ADVANCES IN CARBOHYDRATE CHEMISTRY
VOLUME 8
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Advances in
Carbohydrate Chemistry Edited by MELVILLE L. WOLFROM CLAUDE S. HUDSON National Institutes of Health Bethesda, Maryland
Department of Chemistry The Ohio State Universily Columbus, Ohio
Associate Editors for the British Isles STANLEY PEAT MAURICE STACEY The Universily Birmingham, England
University College of North Wales Bangor, Caernarvonshire, Wales
E. L. HIRST The University Edinburgh, Scotland
Board of Advisors C. B. PURVES J. C. SOWDEN ROYL. WHISTLER
WILLIAML. EVANS HERMANN 0. L. FISCHER R. C. HOCKETT W. W. PIGMAN
Volume 8
1953
ACADEMIC PRESS INC., PUBLISHERS NEW YORK, N. Y.
Copyright, 1953, by ACADEMIC PRESS INC. 125 EAST2 3 STREET ~ ~ NEWYORK10, N. Y.
All Rights Reserved No part of this book may be reproduced in any form, by photostat, microfilm, or any other means without written permission from the publishers. Library of Congress Catalog Card Number (45-11351)
PRINTED I N THE UNITED STATE8 OF AMERICA
CONTRIBUTORS TO VOLUME 8 G. 0. ASPINALL, The University of Edinburgh, Scotland W. W. BINKLEY,Department of Chemistry, The Ohio State University, Columbus, Ohio
H. G. BRAY,Department of Physiology, Medical School of the University, Birmingham, England EDWARD J. HEHRE,Department of Bacteriology and Immunology, Cornell University Medical College, New York, New York C. L. MEHLTRETTER, Northern Regional Research Laboratory, Agricultural Research Administration, U. S. Department of Agriculture, Peoria, Illinois T. MORI,Tokyo University, Tokyo, Japan W. G. OVEREND, The Pennsylvania State College, U . S. A., and Chemistry Department, University of Birmingham, England M. STACEY, Chemistry Department, University of Birmingham, England JAMESM. SUGIHARA, Department of Chemistry, University of Utah, Salt Lake City, Utah R. STUART TIPSON,Department of Research in Organic Chemistry, Mellon Institute, Pittsburgh, Pennsylvania M. L. WOLFROM, Department of Chemistry, The Ohio State University, Columbus, Ohio
V
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PREFACE The sudden death of Claude S. Hudson on December 27, 1952, in his home at Washington, D. C., removes from carbohydrate chemistry one of its great and inspiring leaders. Thus, in the space of a few years, have passed away three great pioneers in this field, W. N. Haworth (1950), J. C. Irvine (1952), and C. S. Hudson (1952). The last had been a guiding spirit for ((Advances in Carbohydrate Chemistry” since its inception in 1944. For the past four years he had been an active editor and, indeed, since his retirement in January, 1951, the editorship of the “Advances” had occupied the greater portion of his time. Dr. Hudson set up exacting standards for his own writing and research and held to a high quality of scholarship in these endeavors. He laid down the policy that the attempt should be made to hold all of the chapters in “Advances in Carbohydrate Chemistry ” to the criteria established in his own writing, while maintaining the integrity of the authors concerned and changing nothing without their full consent. The enforcement of such a policy is not without attendant difficulties; its degree of success may be judged by the readers of these volumes. The manuscripts for the present edition were in the hands of Dr. Hudson at the time of his demise and all had received his editorial attention. Carbohydrate nomenclature has been an ever-present problem in this series. It has recently been the subject of rather extensive consultations between representatives of the American and British carbohydrate chemists, and the final results have appeared in printed form, Chem. Eng. News, 31, 1776 (1953) and J . Chem. SOC.,5108 (1952). Meanwhile, the present volume represents rather a transition stage in this development, particularly as regards the use of the 0-substitution indication, which has been employed only in part. More.uniform usage may be expected in the future. Dr. R. Stuart Tipson has rendered important service in the editing of this volume and has prepared the index. M. L. Wolfrom Columbus, Ohio
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CONTENTS CONTRIBUTORS TO VOLUME 8 . . . . . . . . . . . . . . . . . . . . . . .
v
PREFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
vii
JAMES COLQUHOUN IRVINE . . . . . . . . . . . . . . . . . . . . . . . .
xi
Relative Reactivities of Hydroxyl Groups of Carbohydrates
BY JAMES M . SUGIHARA, Department of Chemistry. University of Utah. Salt Lake City. Utah
. Introduction .
I I1. I11. IV . V VI
. .
1
. . . . . . . . . . . . . . . . . . . . . . . . . . .
Configurational Relationships and Neighboring-group Effects . . . . . . Selective Etherification . . . . . . . . . . . . . . . . . . . . Selective Esterification and Hydrolysis . . . . . . . . . . . . Selective Oxidation . . . . . . . . . . . . . . . . . Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 16 24 38 44
The Chemistry of the 2-Desoxysugars BYW . G . OVEREND, The Pennsylvania State College, U . S . A . , and Chemistry Department, University of Birmingham, England, A N D M. STACEY,Chemistry Departmen.1, University of Biriiiinghain, England
I. I1. I11. IV . V. VI .
Introduction . . . . . . . . Nomenclature . . . . . . . Occurrence and Isolation . . Detection . . . . . . . . . Synthesis of 2-Desoxysugars . Transformation Products . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
45 46
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
53 66 91
49
Sulfonic Esters of Carbohydrates
BY R . STUARTTIPSON, Department of Research in Organic Chemistry, Mellon Institute, Pittsburgh, Pennsylvania
I . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . I1. Methods for Sulfonylation of Carbohydrates . . . . . . . . . . I11. Physical Properties and Chemical Stability . . . . . . . . . . IV . Reductive Desulfonylation and Desulfonyloxylation . . . . . . V. Action of Some Alkaline Reagents on Sulfonic Esters . . . . . . . VI . Action of Alkali-Metal Halides on Sulfonic Esters . . . . . . . . VII . Action of Other Salts on Sulfonic Esters . . . . . . . . . . . . .
. . . . . .
. . . . . .
108 . 111 . 140 . 161 . 165 . 180
. . . 212
The Methyl Ethers of D-Mannose
BY G . 0. ASPINALL,The University of Edinburgh, Scotland . . . . . . . . . . . . . . . . . . . . . .
I . Introduction . . . . . . I1. Monomethyl-D-mannoses I11. Dimethyl-D-mannoses . . IV. Trimethyl-D-mannoses . V . Tetramethyl-D-mannoses
217 . . . . . . . . . . . . . . . . . . . . . . 218 . . . . . . . . . . . . . . . . . . . . . . 220 . . . . . . . . . . . . . . . . . . . . . . 224 . . . . . . . . . . . . . . . . . . . . . . 228 ix
CONTENTS
X
The Chemical Synthesis of D-Glucuronic Acid BY C.L. MEHLTREFTER. Northern Regional Research Laboratmy. Agrakultural Research Administration. U S. Department of Agriculture. Peoria. Illinois I Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 I1 Reduction of 1.4. ~.Glucosaccharolactone . . . . . . . . . . . . . . . 233 111 Oxidation of D-Glucose Derivatives by Various Agents . . . . . . . . . 236
.
. .
.
D-Glucuronic Acid in Metabolism
. .
BY H G BRAY.Department of Physiology. Medical School of the University. Birmingham. England
. . . . . . .
I Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251 I1 D-Glucuronide Formation in Vivo . . . . . . . . . . . . . . . . . . . 252 I11 Structure of Glucuronides . . . . . . . . . . . . . . . . . . . . . . 254 IV Origin of D-Glucuronic Acid and Mechanism of D-Glucuronide Synthesis . 257 V Site of D-Glucuronide Formation . . . . . . . . . . . . . . . . . . . 259 VI Kinetics of D-Glucuronide Formation . . . . . . . . . . . . . . . . . 260 VII Enzymes and PGlucuronide Formation . . . . . . . . . . . . . . . . 261 The Substituted-Sucrose Structure of Melezitose
.
BYEDWARD J HEHRE.Department of Bacteriology and Immunology. Cornell University Medical College. New Ymk.New York: 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277 I1 The Concept of Structural Relationship of Meleeitose and Sucrose . . . . 278 I11 A Bacterial Degradation of Melezitose to Sucrose. . . . . . . . . . . . 282 IV Meleritose Degradation by Cell-free Proteus Enzymes . . . . . . . . . . 287 V Melezitose as a Sucrose-ended Sugar . . . . . . . . . . . . . . . . . 288
. . .
. .
Composition of Cane Juice and Cane Final Molasses
. .
.
BY W W BINKLEY AND M.L WOLFROM. Department of Chemistry. The Ohio Shte University. Columbus. Ohio I Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291 I1 Composition of Cane Juice . . . . . . . . . . . . . . . . . . . . . 292 I11 Composition of Cane Final Molasses . . . . . . . . . . . . . . . . . 303
. . .
Seaweed Polysaccharides
BY T. MORI.Tokyo University. Tokyo. Japan I Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.Agar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I11 Mucilage of B k e a Edulis . . . . . . . . . . . . . . . . . . . . . . IV Carrageenin . . . . . . . . . . . . . . . . . . . . . . . . . . . . V.Fucoidin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . VI Laminarin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VII Other Polysaccharidee . . . . . . . . . . . . . . . . . . . . . . . A~TEIORINDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SUBJEOTINDEX. . . . . . . . . . . . . . . . . . . . . . . . . . . . . ERBATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Contents of Volumes 1-7 . . . . . . . . . . . . . . . . . . . . . .
. . . . .
.
316 317 328 330 340 344 347 351 370 405 . 406
JAMES COLQUHOUN IRVINE 1877-1952 The importance of Sir James Irvine’s contributions to carbohydrate chemistry can best be appreciated by recalling, in the first place, the position attained by this branch of science at the close of the nineteenth century. The significance of the carbohydrates had been recognized both by biologists and by chemists and spectacular advances in our knowledge of this group had been made by Emil Fischer. Despite his genius, however, the available methods of investigation had failed to provide a solution to many fundamental structural problems. Fischer began to turn to other fields of enquiry and there was a feeling that for the moment the limit had been reached in structural work on the sugars. It was Irvine’s great achievement to realize that Purdie’s recently discovered methylation process provided a technique which could be applied in structural work in all branches of sugar chemistry. But to understand more clearly how this came about and why Irvine, still a very young chemist, proceeded to undertake a systematic exploration of the methylated sugars, we must go back a little. James Colquhoun Irvine was born in Glasgow, in the west of Scotland, on 9th May, 1877. His early education was a t Allan Glen’s school in that city and this was followed by a period a t the Royal Technical College, Glasgow. Then in the autumn of 1895 he matriculated at the University of St. Andrews. Here he became a student of the oldest of the Scottish Universities and he quickly acquired an abiding love for the city and for the University in which he was to serve so brilliantly as student, lecturer, professor and principal. When Irvine commenced his chemical studies a t St. Andrews the head of the department was Professor Thomas Purdie, F.R.S., who was quick to appreciate the quality of his new pupil. Purdie was one of the great figures in chemistry and Irvine retained a lifelong regard and veneration for him as teacher and friend. After gaining the B.Sc. degree in 1898 Irvine went to study with Wislicenus a t Leipzig. It was during this period that the idea came to him of using Purdie’s methylation process as a means for the study of the molecular structure of the sugars. He realized from the start the full significance of the new procedure which has been found to be so powerful a weapon that its usefulness is by no means exhausted after fifty years of intensive application by chemists in all xi
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JAMES COLQUHOUN IRVINE
parts of the world. Irvine returned to St. Andrews to develop the new method and so successful was he during the next few years that when Purdie retired in 1909 he was appointed to the chair of chemistry in St. Andrews. I n 1905 he married Mabel Violet, younger daughter of John Williams of Dunmurry, County Antrim, and throughout his career he owed much to her neverfailing devotion and counsel. Sir James and Lady Irvine had three children: two daughters, and a son who died while on active service during the second world war. From 1909-1914, a period which included the celebration in 1911 of the 500th anniversary of the foundation of the University, the work on sugars was continued without interruption but at the outbreak of the first world war in 1914 academic work ceased and the laboratories were hurriedly re-organized for the preparation on a large scale of fine chemicals and medicinal substances which were urgently required by the British and Allied Governments. Few trained chemists were available and facilities for the manufacture of fine chemicals were woefully inadequate. With the assistance of W. N. Haworth (afterwards Sir Norman Haworth) Irvine organized the laboratories for the preparation of dulcitol and other carbohydrates, orthoform and novocaine. During the later stages of the war much difficult and dangerous work was carried out on the manufacture of mustard gas. It would take long to tell how the many steps of the various syntheses were itemized and reduced to a series of routine operations which could be performed successfully by voluntary assistants, many of whom had never previously handled a piece of scientific apparatus. Fundamental research was resumed in 1919 and in a very short time an enthusiastic group of workers had gathered together for a systematic study of the sugar group. Irvine was then a t the height of his powers as teacher and director of research. No one who had the good fortune to attend his lecture courses will ever forget them. The chemistry lecture was assuredly one of the events of the day, with the long lecture bench crowded with experiments by which all the important points were illustrated. The timing of these was so exact that there was no interruption of the argument, and speech and experiment became perfectly integrated. The lectures themselves were models of clear exposition inspiring the audience with a keen desire for further understanding. They were delivered in the grand manner and in the tradition of the old masters of chemical science. Irvine’s method was different, but equally stimulating and effective in the informal discussions with small groups of research workers. On these occasions concise summaries of recent publications were given with an ease and clarity which delighted and amazed his hearers. Equally memorable were his talks a t the bench with
JAMES COLQUHOUN IRVINE
...
Xlll
research students whose difficulties appeared much less formidable after the suggestions and kindly encouragement they received during Irvine’s rounds of the laboratories. I n 1921 Irvine was appointed Principal and Vice-Chancellor of the University of St. Andrews. A new stage in his life now began, and he had to face tasks which might well have daunted a man of lesser faith and spirit. I n his early days at St. Andrews he found the University, old in years and proud of its tradition of learning, suffering from lack of buildings and equipment for scientific research. The number of students was small and the financial position was difficult. But Irvine possessed an unconquerable faith in the destiny of St. Andrews and as the result of a rare combination of vision and driving power in practical affairs he succeeded during his thirty-one years of office as Principal in changing the face of the University. It stands indeed today a monument to the inestimable services of this distinguished Principal and Vice-Chancellor. Developments took place in all faculties. New buildings were constructed in St. Andrews and Dundee, where rapid advances were being made, particularly in the schools of medicine and engineering. In St. Andrews a graduation hall was built and the student life of the University was transformed by the construction of new halls of residence and the extension of existing buildings. This and the institution of a system of Regents responsible for guiding and advising small groups of students were projects to which Irvine gave special at,tention and he was greatly helped in reaching this goal by the generous Harkness benefactions to the University. Sir James Irvine’s services to his University were so great that no adequate account can be given in a brief notice. It is no secret that on various occasions he was asked to undertake positions involving wider spheres of responsibility and activity, yet he chose to remain in St. Andrews, feeling that his real life-work lay in the University and city he loved so well. Nevertheless he could not escape calls to act as adviser and administrator outside the walls of St. Andrews and as the years passed he found himself called upon to play a more and more prominent part in these extramural activities. He gave much time and thought to the preservation of the historical buildings in St. Andrews. He served on many boards and committees, often as Chairman. These included the Scottish Universities Entrance Board and the Forest Products Research Board of the Department of Scientific and Industrial Research (Chairman, 1927-1939). He was Chairman of the Advisory Council of the Scottish Education Department (1925-31), of the Inter-University Council for Higher Education in the Colonies (1946), of the Viceroy’s Committee on the Indian Institute of Science (1936), and of the Adult
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Education Committee for Scotland (1927-1929). He was a member of the Prime Minister’s Committee on the Training of Biologists (1931). He played a notable part in the foundation of the University College of the West Indies. This was work in which he was deeply interested and it was a great satisfaction to him to be present at the inauguration of the College and to realize that in many respects, including the adoption of the Red Gown by its students, it was founded on the traditions of his own University in Scotland. He had a warm regard and respect for the United States of America and took special pride in his work for the Pilgrim Trust and the Commonwealth Fellowship Fund. He travelled widely in the U. S. A. where he made many lasting friendships. Amongst these many activities may be mentioned his visits to Williamstown as Foreign Lecturer at the Institute of Politics (1926), t o Princeton as Vanuxem Lecturer (1929) and to Yale as Woodward Lecturer (1931). In his character and personality Irvine displayed a wide versatility. He was a great scientist yet he possessed in full measure a love and understanding of humanistic studies which were reflected in his writing and in the appeal of his oratory. He had unusual powers in reducing complicated problems to their essentials, yet his memory could retain the minutest detail. Persuasive in argument, he was forceful and determined in carrying through cherished projects once the decision had been made. He was genial and charming in human relationships and one to whom his students turned as a trusted friend and counsellor. He was deeply sensible of the traditions and aspirations of the University as a whole, but he could always find time, no matter how pressing the business of the moment, to write in his own hand letters of kindly encouragement and congratulation t o his youthful colleagues and acquaintances. Throughout his life he spent his energies freely, finding relaxation during such vacations as came his way, in swimming, fishing and reading. The war-time years had been a great strain but he faced the post-war problems with his usual zest. It was his great desire to pilot the University through the difficult period of re-adjustment and reconstruction but this wish remained unfulfilled. He had a very serious illness in the summer of 1951 and although he made a remarkable recovery he was never again able to undertake in full the multifarious duties of the Principalship. He insisted, nevertheless, in doing more than his strength could bear, and only two days before his death, which came suddenly on June 12th, 1952, he had presided over a long and important meeting of the University Court at St. Andrews. His contributions to learning as teacher and investigator, his devotion to College and University, his achievements in many-sided activities in the widest fields of scholarship and statesman-
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ship ensure for him a lasting place as one of the most illustrious in the long line of Principals of the University of St. Andrews. Irvine received many honors in recognition of his achievements. The work he carried out during the first world war brought him the C.B.E. in 1920. Five years later he was given a Knighthood and in 1948 he was accorded the high honor of K.B.E. His scientific work was recognized by his election to the Fellowship of the Royal Society in 1919. He received the Davy Medal of the Royal Society in 1925 and the Longstaff Medal of the Chemical Society in 1933. He became a Fellow of the. Royal Society of Edinburgh in 1917, being Vice President (1922-25) and Gunning Victoria Jubilee Prize winner, one of the Society’s highest honors, in 1940. He was an honorary member and Willard Gibbs Medallist of the American Chemical Society, Medallist and honorary member of the Franklin Institute and honorary member of the American Philosophical Society. He was President of the Chemistry Section of the British Association for the Advancement of Science at the Hull meeting in 1922. Academic honors included the degrees of Ph.D. (Leipzig), D.Sc. (St. Andrews), Hon. D. Sc. (Liverpool,Princeton and McGill), Hon. Sc. D. (Cambridge, Pennsylvania and Yale), Hon. D.C.L. (Oxford and Durham), Hon. LL.D. (Glasgow, Aberdeen, Edinburgh, Wales, Toronto, Columbia and New York). He was a Justice of the Peace and Freeman of the City of St. Andrews. Irvine’s scientific work was essentially that of a pioneer. He understood the full power of Purdie’s methylation process as a method for structural investigations in the sugar group and while he was still working for his doctorate at Leipzig he wrote to Purdie outlining the whole field. At that time little was known with certainty concerning the fine structure of the simple sugars and still less of the disaccharides and polysaccharides. Irvine realized that the transformation of the reactive hydroxyl groups of the sugars into stable methyl ethers by the use of Purdie’s reaction with silver oxide and methyl iodide provided a method by which the next stage in carbohydrate chemistry could be initiated. He indicated how the procedure could be elaborated to determine the position of the linkages in the disaccharides and in the higher sugars. As a necessary preliminary to such work, however, it was essential to have a series of reference compounds and on returning to St. Andrews he began a systematic study of the methylated sugars. Purdie and he reported on the alkylation of sugars at the meeting of the British Association for the Advancement of Science in 1902, and this was followed by a note on applications t o disaccharides, given at the following meeting of the Association in 1903. At St. Andrews work was continuing on the preparation and properties of the methyl derivatives of the simple sugars, amongst which mention may
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be made of tetramethylglucose and its a- and P-methyl glucosides, and the carresponding derivatives of galactose, mannose and other sugars. Derivatives of these methylated sugars, for example oximes, anilides and hydrazones were also prepared and their properties studied. It was shown also that a non-reducing octamethyldisaccharide of the trehalose type was formed by the condensation of two molecules of tetramethylglucose under the influence of an acid catalyst in a non-aqueous medium. Another stage in the development of the sugar work came with the preparation of the partly methylated derivatives. These were obtained in various ways and the investigations led to detailed studies of the isopropylidene derivatives of glucose, fructose, and mannose. Much was learned in this difficult field but in many instances exact structural formulas could not be assigned until the nature of the ring systems present in the stable and labile forms of the sugars became known in later years. Irvine's first publication (1899) dealt with the rotatory powers of the optically active methoxy- and ethoxy-propionic acids prepared from lactic acid. In those early days the Purdie reactJionafforded so rich a field for investigation that Irvine and his collaborators continued work on various types of hydroxy bodies in addition to the sugars. There appeared papers on the isopropylidene derivatives and methyl ethers of glycerol and mannitol, and on the chemistry of benzoin and benzoin-like materials. The constitution of the glucoside salicin was studied and its pentamethyl ether was synthesized. Another example from the monosaccharide group of the insight which led Irvine to discern which problems were of special importance is found in his work on glucosamine, in the course of which'he endeavored to decide whether this substance was related stereochemically to D-glucose or to D-mannose. He discovered that it could be transformed at will into derivatives of D-glucose or D-mannose by alternative procedures. Here again much important information was gleaned, but the final resolution of the problem came only many years afterwards when later workers, by using entirely novel methods, provided a proof of the presence of the D-glucose type of configuration in glucosamine. It had been realized from the beginning that the final goal was the application of the new methods to structural studies in the wider fields of oligosaccharides and polysaccharides. The important reference substance, 2,3,6-trimethyl-~-glucosewas isolated by Denham in the course of work at St. Andrews on the methylation of cellulose in which he made use of dimethyl sulfate as the methylating agent. At about the same time (1912-13) W. N. Haworth who was then a member of staff a t St. Andrews, became interested in carbohydrate
JAMES COLQUHOUN IRVINE
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chemistry and developed the dimethyl sulfate method, applying it to sucrose, cellobiose, lactose, maltose and raffinose. Irvine’s own special interests now leaned more towards the polysaccharides and he began (with Miss E. S. Steele) a series of studies on the methylation of inulin and on the partly methylated fructoses obtainable from the methylated polysaccharide. Investigations into the structure of cellulose were also undertaken and reference may be made to the quantitative transformation of cellulose into methyl D-glucoside, the preparation of trimethylcellulose and the proof, derived from examination of its hydrolysis products, that methylated cellulose is built up exclusively, or almost exclusively, of residues of 2,3,6-trimethyl-~-glucose. Pioneering work was carried out also on the structure of starch and certain degradation products of starch, using the methylation technique. These studies involved a reconsideration of the then-accepted structure of the disaccharide maltose and proof was given that octamethylmaltose yields on hydrolysis 2,3,6-trimethyl-~-glucose. Residues of this sugar were shown therefore to constitute some of the units of which the starchmoleculewascomposed. Irvine had always been specially interested in sucrose and he devoted much attention to attempted syntheses of this important sugar. He examined with meticulous thoroughness the condensation of D-glucose with derivatives of D-fructofuranose but, in no case could any trace of sucrose be detected, a conclusion which has been confirmed by many subsequent investigators. An isomeride of sucrose was obtained the properties of which were studied. In later years much important work was carried out in the St. Andrews laboratories on anhydro-sugars and their derivatives (G. J. Robertson) and on the nitrate esters of methylated sugars (J. W. H. Oldham). Irvine never diminished his keen interest in this work but it was inevitable that less time could be devoted to chemical research after he had assumed the onerous duties of Principal and Vice-Chancellor in 1921. It was characteristic of him, however, that only a few days before his death he was busy propounding long-term schemes of research on possible developments of sugar derivatives for use in chemotherapy. Irvine’s pioneering activities covered a wide range of problems in carbohydrate chemistry. His publications are characterized by the clear and precise thinking and by the elegance of style which are evident in all his writings. The ideas he put forward have been singularly fruitful and the exploits of the small band of research workers in St. Andrews half a century ago inspired an ever-increasing volume of important work which has been carried out since those days in many different laboratories in all parts of the world. E. L. HIRST
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RELATIVE REACTIVITIES OF HYDROXYL GROUPS OF CARBOHYDRATES
BY JAMESM. SUQIHARA Department of chemistry, University of Utah, Salt Lake City, Utah
CONTENTS I. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . 11. Configurational Relationships and Neighbo 1. Acyl Migration.. . . . . . , . . . . . . . . . . . . . . 2. Anhydride Formation. . . . . . . . . . . . . . . . . 3. Osazone Formation... . . . . . . . 4. Glycol Complexes.. . . . . . . . . . . . . . . . . . 111. Selective Etherification. . . . . . . . . 1. Methyl Ethers.. . . . . . . . . . . . . . . . . . . . . . 2. Other Ethers.. . . . . . . . . . . . . . . IV. Selective Esterification and Hydr 1. Tosyl and Mesyl Estere.. . . . . . . . . . . . . .
..........
16
...................
3. Other Esters.. . . . . . . . . . . . . . . . . . . . . . . . . ., . . . . . . . . . . . . . . . . . . 33 V. Selective Oxidation.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 VI. Conclusions. . . . . . . . . . . . . . . . . ................ . . . . . . . . . . . . . 44
I. INTRODUCTION Differences in reactivities of the hydroxyl groups of carbohydrates have been recognized for some time. Certain of these differences are understandable from the point of view of classical organic chemistry; in this respect the differencesin reactivity of primary and secondary alcohols may be cited. The advent of a much better knowledge of mechanisms of organic reactions, in many cases initiated and promoted in the area of carbohydrate chemistry, has clarified some of the complex properties of the polyfunctional carbohydrates. Further impetus and stimulus in this direction should be of material value in clarifying the reactions and possibilities of carbohydrate chemistry. A better understanding of the relative reactivities of hydroxyl groups in carbohydrates may be of considerable value in the field of syntheses. The usual approach t o the preparation of partially or heterogeneously substituted polyhydroxy compounds requires the use of blocking groups, which are subsequently removed. Any synthesis which permits the 1
2
JAMEB M. SUGIHARA
elimination of several steps in a multistage process, is obviously desirable provided that the yields and operations are comparable. Some direct synthetic reactions that have been found to be possible by the proper control of conditions are well established. Further progress in this direction has been aided, and should continue to thrive, by the proper application of refined separation methods, such as chromatography, either alone or in combination with ion-exchange purification. The resolution of complex reaction mixtures, containing substances of very similar properties, has been realized in many cases. Thus the execution of a reaction under optimum conditions to realize the maximum amount of the desired substance, and followed by chromatographic and ion-exchange separation of the products and excess reactants, should permit many new direct syntheses to be attainable. Much of the earlier work on selective reactivity was motivated by the preparation and study of polysaccharides of industrial importance. It appears that more effort may have been exerted in this field than in that of monomeric chemistry. Some of the topics that will be discussed in this chapter have been included in previous volumes of this publication and in other review articles. Such items will be briefly reconsidered from the point of view of selective reactivities of hydroxyl groups.
11. CONFIGURATIONAL RELATIONSHIPS AND NEIGHBORING-GROUP
EFFECTS Configurational relationships and neighboring-group effects are undoubtedly of primary importance in modifying the behavior of carbohydrates. In this connection certain types of reactions, which are reasonably well established, are described in this section because they are of importance for the explanation of the selective reactions of carbohydrate hydroxyl groups. 1. Acyl Migration The isomerization of a compound by intramolecular transesterification has been observed many times.' Fischer2 was the first to observe
H-C-OH
I
H-C-0
I
/ \
OH
H-C-0-
I
8
(1)
-R
(1) For a brief review see E. L. Hirst and S. Peat, Ann. Repts. on Progr. Chem. (Chem. SOC.London), 81,172 (1934). (2) E. Fischer, Ber., 63, 1621 (1920);see A. P.Doerschuk, J. Am. Chem. Soc., 74, 4202 (1952).
RELATIVE REACTIVITIES O F HYDROXYL GROUPS
3
this reaction and to postulate a mechanism based upon a neighboring group effect with an ortho acid ester as an intermediate (1). I n most instances where acyl migration has been observed, such as in the methylato form methyl tion of methyl 2,3,4-tri-0-acetyl-a-~-glucopyranoside 2-0-methyl-3,4,G-tri-O-acetyl-a-~-glucopyranos~de,~ the proximity in space (2) of the migrating group to the free hydroxyl group would be sufficiently close to permit an intermediate cyclic structure as proposed by Fischer.2 The methylation per se is not the determining factor; the
alkaline conditions imposed in using silver oxide doubtless must play the important role. When the analogous benzoyl ester, methyl 2,3,4-tri-Obenzoyl-a-D-glucopyranoside, was methylated, the expected 6-0-methyl derivative was ~ b t a i n e d . ~Acyl migration has been observed in other methylation reactions. The methylation of 1,2,3,6-t,etra-O-acetyl-fi-~glucopyranose (I) with methyl iodide and silver oxide gives methyl 2,3,4,6-tetra-0-acetyl-fi-~-glucopyranoside (11); 5 migration of acetyl from position 1 t o position 4 occurs. A study of molecular models appears t o indicate the probability of a shift sequence 1 + 6 + 4 through orthoester intermediates. 5-0-Acetyl- 1,2-0-isopropylidene-3-0-methyl-G-O-tritylD-glucofuranose (IV) is obtained in the methylation of 3-0-acetyl-1,2-0isdpropylidene-6-0-trityl-D-glucofuranose (III).6 Robertson' obtained AcO
b
-1
y
MeOCH
I
HCOAc
HkOAc
b
AGO H HkOH
L
H 0-
(3) (4) (5) (6) (7)
hiel
-
AoO
b
AcO H
I
HCOAc
h
H 0-
W. N. Haworth, E. L. Hirst and Ethel G. Tcece, J . Chem. Soc., 2858 (1931). B. Helferich and E. Giinther, Ber., 64, 1276 (1931). B. Helferich and W. Klein, Ann., 466, 173 (1927). 1,. v. Vargha, Ber., 67, 1223 (1934). G. J. Robertson, J . Chem. Soe., 737 (1933).
T
A
(4
HO-lA%,d
HO-
HhOH
H OAc
LH*OCPhs
A
AHnOCPha
I11
IV
a mixture of methyl 2,3,6-tri-O-methyl- and 2,3,4-tri-0-methyl-a-~-g1ucopyranosides from the methylation of methyl 4-0-acetyl-2,3-di-O-methyla-D-glucopyranoside, and further examples of acyl migration have been noted. In the majority of the cases the movement of acyl is toward the primary hydroxyl group. The comparative values of the equilibrium constants of acetates of primary and secondary alcohols*would favor the shift in this direction. Helferich and Kleine found that 1,2,3,4-tetra-Oacetyl-0-D-glucose is isomerized by the alkali present in soft glass to form Molecular models again show the lJ2,3,6-tetra-O-acety1-~-D-glucose. probability of an acetyl shift from position 4 to 6. 3-0-Acetyl-1,2-0isopropylidene-D-glucofuranose (V) forms the 6-0-acetyl derivative (VI) in good yield.'O The same rearrangement occurs with 3-0-benzoyl-1,20-isopropylidene-D-glucofuranose." These reactions are catalyzed by alkali. I n all the investigations cited so far, suitable cyclic ortho acid ester structures with little strain are sterically possible. \ HCO
HCO
HAOH
HAOH
A&OH V
AHaOAc VI
(8) G. B. Hatch and H. Adkins, J. Am. Chem. Soc., 69, 1694 (1937). (9) B. Helferich and W. Klein, Ann., 460, 219 (1926). (10) K. Josephson, Ann., 472, 217 (1929); H. Ohle, E. Euler and R. Lichenstein, Ber., 62, 2885 (1929). (11) H. Ohle, Ber., 67, 403 (1924).
RELATIVE REACTIVITIES OF HYDROXYL GROUPS
5
Acyl migration has been shown to occur in an acid solution. Brigl in boiling acetylene and Gruner l 2 placed 1,6-di-O-benzoyl-~-mannitol tetrachloride with a little p-toluenesulfonic acid as catalyst and obtained three compounds, which they designated as 2,4-monoanhydro-~-mannito1 1,6-dibenzoate, 2,4 :3,5-dianhydro-~-mannitol l,Bdibenzoate, and 2,5-monoanhydro-~-mannitol1,6-dibenzoate. However, Hockett and coworkers18 reinvestigated this reaction and they have established the correct structures as being 1,4-monoanhydro-n-mannitol2,6- (or 3,6)dibenzoate (VII), 1,4 :3,6-dianhydro-~-mannitol 2,5-dibenzoate (VIII), 1,6-dibenzoate (IX). These findings and 2,5~-monoanhydro-~-glucitol were based upon lead tetraacetate oxidation studies. I n VII and VIII HZC? B ? i f r i HOCH
HbOH
I
CH~OBZ VII
BeOk
1
1
H~COBZ
HO H HLOH
B e!:
0 H2 VIII
H 0AH*OBz IX
benz,oyl migration could have occurred through an intermediate cyclic ortho ester. Anhydro formation may have involved the initial formation of a tosyl ester with p-toluenesulfonic acid. Such an intermediate would permit the necessary inversion about carbon atom 2 in the formation of IX (see the following section on anhydride formation, page 7). I n the classical Wohl degradati~n,'~ a diacetamido derivative is formed as an intermediate. Isbell and Frush16 have proposed a mechanism for its formation, based upon two successive acetyl migrations. The migration of acyl from nitrogen to oxygen has also been observed to occur. In epimeric acetylinosamines McCasland16 noted that a cis relationship of acetylamino to hydroxyl is necessary for facile migration in dilute acid in this rearrangement reaction in which configuration is retained. Among (12) P. Brigl and H. Grliner, Ber., 60, 1945 (1933); 67, 1582 (1934). (13) (a) R. C. Hockett, H. G. Fletcher, Jr., Elizabeth L. Sheffield and R. M. Goepp, Jr., J . Am. Chem. Soc., 68, 927 (1946); (b) R. C. Hockett, H. G. Fletcher, Jr., ElizabethL. Sheffield, R. M. Goepp, Jr., and S. Solteberg, ibid., 930; (c) R. C. Hockett, M. Zief and R. M. Goepp, Jr., ibid., 935. (14) A. Wohl, Ber., 26, 730 (1893). (15) H. S. Isbell and Harriet L. Frush, J . Am. Chem. Soc., 71, 1579 (1949). (16) G. E. McCasland, J . Am. Chem. Soc., 73, 2295 (1951). Further references are contained in this article.
6
JAMES
M. SUGIHARA
the recent studies concerned with this migration, van Tamelen17 has obtained further evidence favoring a cyclic intermediate in the relative ease of acyl migration of Cis and trans N-(pnitrobenroyl)-2-aminocyclopentanols. The &-isomer (X) reacts readily to form the hydrochloride OH
-
.-T=O
NHS
-c-o-c-cH~
I
cH3-!T-
b
OH
I
H-C-FHt
I “ir I 8
-C-O-C-CH3
cH’-8-r
-
,*‘
iHa
I
CHS-C-0-COH
‘
I 1
-C-OH
I
CH3-C-C-
1
A I I
0
I
NI13
-4-OH
t--
A
1
CH3-C-C-
d I
I
1 8 I CH~-C--COH -c-OH I C-I GO-
I /C‘’ *OH
-C-O$
H-C-KH-C-CHI
I
H 1 NH-C-NHC-CHI
CHS
OH
CYH
H
I
H-C-NH
H
I
-
I !
CH J-C-NH-C-NHC-CH~ 0II
-C-OH HO-C-
I I
salt of cis-2-aminocyclopentanol p-nitrobengoate (XI) while the transisomer gave poor yields of the analogous amine hydrochloride over a much longer period of time. This difference is attributed to the auppression of formation of the highly strained cyclic form of the trans-isomer. Orthoesters are formed by a similar mechanism in the Koenigs and KnorrI8 method of synthesis of glycosides from certain acetylglycosyl halides.lg Isbell and Frush20 have shown that the spatial relationship (17) E. E. van Tamelen, J . Am. Chem. Soc., 75, 5773 (1951). (18) W.Koenigs and E. Knorr, Ber., 84, 957 (1901). (19) Orthoester formation is reviewed by E. Pacsu, Advances in Carbohydrate Chem., 1, 77 (1945). (20) H. S. Isbell and Harriet L. Frush, J . Research Natl. Bur. Standards, 48, 161 (1949).
RELATIVE REACTIVITIES O F HYDROXYL GROUPS
7
of the neighboring acetoxyl group on carbon atom 2 to the halogen atom on carbon atom 1 determines whether normal glycoside formation occurs or orthoesters are formed. With a trans relationship (XII) between these
X
XI R = p-O&CGHs-
two substituents an intramolecular back-side displacement reaction takes place with inversion of configuration about carbon atom 1. Alcoholysis of the resulting solvated orthoester int,ermediate (XIII) leads to the formation of the orthoester (XIV). CHs;.C, q o H - A q
ROH'
0-C-H XI1
-
;,o-q-
CHa-C,
0-C-H ROiH XI11
I
'
'0-C-H XIV
The extensive work of Winstein and his coworkers2' on the general concept of the influence of neighboring groups and atoms on the reactivity toward displacement reactions has added much information indicating the validity of cyclic reaction intermediates. 2. Anhydride Formution Anhydro sugarszz and anhydro-pentitols and - h e ~ i t o l shave ~ ~ been described in earlier volumes of this publication and the mechanism of anhydro ring formation by alkaline reagents has been discussed. The method of formation of ethylene-oxide and tetrahydrofuran derivatives appears to involve the back-side approach of a hydroxyl group to a carbon atom containing an attached tosyl group (or any sulfonic ester group), a halogen atom, or a trimethylamino group. Creation of a new carbon to oxygen bond is accompanied by simultaneous elimination of tosyloxy, (21) S. Winstein and R. Boschan, J . A m . Chem. Soc., 7 2 , 4669 (1950); S. Winstein and K. C. Schreiber, ibid., 74, 2171 (1952); and preceding articles in each series. (22) S. Peat, Advances in Carbohydrate Chem., 2, 37 (1946). (23) L. F. Wiggins, Advances in Carbohydrate Chem., 6 , 191 (1950).
8
JAMES M . SUGIHARA
halogen, or trimethylamino, and inversion of configuration about the carbon atom from which the substituent is eliminated. When fixed in a semi-rigid ring structure, the spatial arrangement of the hydroxyl and the group or atom that is eliminated must be trans to permit ring formation. I
"oq-k-G I
-
I
I C-
+ ZH
0 I: C-
-c-c-
I
-c-c-
If-c- --,c-z
b./'
I
I
- -Y\o/Y-I I I
I
# -kZH
I H Z = -OTs, -X (halogen), or -N(CHJ8
The investigations of Lucas and his coworkers with 2,3-disubstituted butanes have contributed much to the clarification of the mechanism of ring closure and ring opening of ethylene oxides and ethylene imines. ~-threo-2,3-Butanediol(XV) is converted into a chlorohydrin (XVII) via the diacetate (XVI).24 In the formation of the chlorohydrin (XVII) a Walden inversion occurs.26 The dehydrochlorination of XVII with
x""
HO H
1
HCOH AHa
xv
CHa
-
AcnO CsHd
A
AcO H
iH3
HClHO H
HAOAc -+ C1AH AHa XVI
AH3 XVII
alkali yields an epoxide (XVIII), ~-trans-2,3-epoxybutaneand a second inversion is involved in the ring closure.2s In like manner a Walden inversion is involved in the formation of cis-2,3-epoxybutane (XX) (XIX).28 from the dehydrobromination of ~,~-threo-3-bromo-2-butanol I n ring opening another inversion is involved; cis-2,3-epoxybutane (XX) yields ~,~-2,3-butanediol (XXI) upon hydrolysis. 27 The stereochemistry of the closing and opening of the ethylene imine ring is entirely analogous.28 A mechanism for the formation of levoglucosan (1,6-anhydro-p-~glucopyranose) from glucopyranosides and glucopyranosylammonium (24) H. J. Lucas and H. K. Garner, J. Am. Chem. Soc., 70, 990 (1948). (25) H. J. Lucasand C. W. Gould, J . Am. Chem. Soc., 08,2541 (1941); S.Winstein and H. J . Lucas, ibid., 61, 1581 (1939). (26) S. Winstein and H. J. Lucas, J. Am. Chem. SOC.,61, 1576 (1939). (27) C. E. Wilson and H. J. Lucas, J . Am. Chem. Soc., 68, 2396 (1936). (28) F. H. Dickey, W. Fickett and H. J. Lucas, J . Am. Chem. Soc., 74,944 (1952).
RELATIVE REACTIVITIES O F HYDROXYL GROUPS
9
halides has been proposed by McCloskey and Coleman.29 Montgomery, Richtmyer and Hudson30 had shown earlier that the alkaline degradation of certain phenyl 0-D-glycopyranosides proceeded smoothly to form glycosans < 1,5 >0< l,6 >. McCloskey and Colemanz9 noted that in
CIkH
-
AH3 XVII CHa BrkH HAOH AHa XIX CHJ I
HAH3 XVIII
x""-
H BrKox-rH+
HoAH
H-A/
AH3
0 '
AHa
xx CHI I
CHa I
all compounds in which facile reaction occurs the phenoxy group is trans to the hydroxyl group on carbon atom 2. This structural relationship suggested the possibility of the formation of a l12-epoxide. This was in contrast to the 113-anhydro derivative proposed earlier by Micheel
and Micheel.a1 The l13-anhydro ring appeared improbable because of the high strain involved and because substitution in the 3-position does not inhibit reaction. Moreover, from the numerous illustrations which have been described, the formation of a propylene oxide ring, when an (29) C. M. McCloskey and G. H. Coleman, J . Org. Chem., 10, 184 (1945). (30) Edna M. Montgomery, N. K. Richtmyer and C. S. Hudson, J. Am. Chem. SOC.,66, 3, 1848 (1943). (31) F. Micheel and Hertha Micheel, Ber., 63, 258 (1932).
10
JAMES M. BUGIHARA
ethylene oxide ring is possible, is not to be expected. 32 Further evidence3s for the proposed mechanism29was obtained when the formation of levoglucosan from 3,4,6-tri-0-acetyl-l,2-anhydro-~-glucopyranose and the inertness of phenyl 2-O-methyl-~-~-glucopyranoside to alkali were demonstrated. On the basis of this mechanism two Walden inversions H C CHtOH Y F ' h
KO
OH
H
,:H
OH-
(inversion)
H 0-H Phenyl 8-D-gluoopyranoside
HCZ CHP-0,
HO
OH
/
H
I1
H 1,2-Anhydro-~-glucopyranose
H
HO
OH
H OH Levoglucosan
are involved at carbon atom 1 in the closing and opening of the ethylene oxide ring. 3. Osazone Formation34 Since the discovery of the reaction of phenylhydrazine with sugars to form osazones by F i s ~ h e r many , ~ ~ investigations have utilized this reaction in the identification and separation of sugars, but the precise structures of osazones and their mode of formation are still in There is no doubt, however, that the initial reaction involves the formation of a hydrazone, which then reacts further to yield eventually a bis-l12-hydrazone or osazone. Several mechanisms3' have been proposed for this reaction. That of W e ~ g a n din , ~which ~ an Amadori rearrangement is proposed, has considerable merit. 37 Illustrations of unusual osazone formation are described by Bonner and Drisko. When phenyl P-D-xylopyranosyl sulfone (XXII) or 0-D-glucopyranosyl sulfone (XXIV) is oxidized by periodic acid, a dialdehyde oxidation product (XXIII or XXV), which is susceptible toward further oxidation, is obtained. The reaction of XXIII or XXV with phenylhydrazine yields glyoxal phenylosazone and benzenesulfinic acid. Surprisingly, both XXII and XXIII react with phenylhydrazine to form n-xylosazone and D-glucosazone, respectively. (32) W. P. Evans, Z. physik. Chem., 7, 337 (1891). (33) M. P. Bardolph and G. H. Coleman, J. Org. Chem., 16, 169 (1950). (34) See the review article by E. G. V. Percival, Advances in Carbohydrate Chem., 3, 23 (1948). (35) E. Fischer, Ber., 17, 579 (1884). (36) F. Weygand, Ber., 73, 1284 (1940). (37) Further evidence for this mechanism was advanced by F. Weygand and Margaret Reckhaus, Chem. Ber., 82,438 (1949). (38) W. A. Bonner and R. W. Drisko, J. Am. Chem. Soc., 73, 3699, 3701 (1951); see E. Blanchfield and T. Dillon, ibid., 78, 647 (1953).
RELATIVE REACTIVITIES O F HYDROXYL GROUPS
11
I
I
Ho?H H3-60SUd
'OIH c-
Ho?H -OYH
IIIXX 1-
IIXX
1
H3-'OSW
H3-'OS4d 'OIH
HfoH
c-
OH3
-OfH
T
AXX
JO
IIIXX
0
HOZI
OH3-
il-'Of396
1
O'H
PhS02H 4-CHO PhNHNHn
HAOH -
osazone
I
Smith and Andersonag prepared the three 3-C-phenyltrioses, 3-Cphenylglyceraldehyde (XXVI), a#-dihydroxypropiophenone (XXVII), and 3-C-phenyldihydroxyacetone (XXVIII) and found that XXVI is (39) L. I. Smith and R. H. Anderson, J . Org. C h m . , 61, 963 (1951).
JAMES M. SUGIHARA
12 CHO
CHsOH
CHZOH
&HOH
bHOR
b=O
AHOH
b=O
AHOH
Ah XXVII
Ph
Ah XXVI
I
I
H+ CHzOH
ArNH-+CH LHOH bHoH Ah
AHOH
b-OH
+
?h
xxx
XXIX
1
-H+
ArNH-CH
XXVIII
IH+ CHzOH +&OH bHOH
I
Ph XXXI
1
-H+
CHiOH
&OH
AOH
bHOH
EOH
l!’h
Ah
1
I
-0H-
1
-0H-
ArNHCH
+CH2
O H !(
AOH
+AH
JOH
A
Ah
CHO
CHa
I
XXXII
I
XXXIII
converted into benzylglyoxal (XXXII) with primary aromatic amines via the Amadori rearrangement. The phenylketotrioses, XXVII and XXVIII are transformed into acetylbensoyl (XXXIII) in dilute acetic acid in the absence of an amine. The primary amine is believed to stabilize a carbonium ion (XXIX) from X X V I and this intermediate is
RELATIVE REACTIVITIES OF HYDROXYL GROUPS
13
believed to be necessary for the rearrangement. In the case of XXVII and XXVIII the secondary carbonium ions (XXX and XXXI) have sufficient stability in tho absence of an amine. The preferential formation of an osarone from a reducing sugar such that the hydroxyl group on carbon atom 2 is involved (but not other hydroxyl groups present), poses a question which has not been satisfactorily answered. Fieser and Fieser‘O suggest that stabilization of the bis-hydrazone through chelation may prevent further reaction. Perciva134 states that an equally satisfactory explanation may be made by NHPh
I
N
N
// LH
HC
HC
‘N-Ph
kHPh
assuming the phenylosaaone structure shown in XXXIV. HC=NNHPh
f iI HLOH
A
0 HI XXXIV
These recent investigations may lead to further clarification of the mechanism of osarone formation] one of the classical sugar reactions. 4. Glycol Complexes
Much knowledge of the structures of carbohydrates has been gained by reagents which selectively attack two hydroxyl groups. In addition to those substances which react with glycols to form isolable derivatives, there are certain compounds which form rather unstable] but nonetheless important, complexes. I n this category the cuprammonium-glycoside complexes have been shown by Reeves“ to be very valuable for fine structure determination. Using compounds of known structure, Reeves (40) L. F. Fieser and Mary Fieser, “Organic Chemistry,” D. C. Heath and Co., Boston, 1950, p. 371. (41) R. E. Reeves, Advances in Carbohydrate Chem., 6, 107 (1951).
14
JAMES M. SUGIHARA
haw shown that optimum complexing 2ccurs when the two hydroxyl groups are located at a distance of 2.51 A, which is the distance between the oxygen atoms in the hydroxyl groups in the true cis arrangement. Tendency to complex decreases with increased distance up to 3.45 8, where no detectable reaction occurs. The reactivity of acetone, or any aldehyde or ketone, with glycols to form a cyclic acetal is probably determined by the same factor, namely, spatial relationship of the hydroxyl g r ~ u p s . ~There ~ . ~ appears ~~ to be a correlation in the formation of isopropylidene derivatives and cuprammonium complexe~.~'The rate of cleavage of an adjacent glycol linkage with lead tetraacetate or periodic acid is dependent upon spatial relationships of the hydroxyl groups. 4' It is probable that initial complexing occurs and then is followed by oxidative degradation. *Ib With a true trans relationship and added structural rigidity to prevent movement from this position, Dimler and found that D-glucosan < 1,4> a < 1,6> (XXXV) and
f3
HHCOH rC
xxxv
0
HCOH
I
1
0
H&
XXXVI
D-galactosan < 1,4> (Y < 1,6 > (XXXVI) are unreactive t o both lead tetraacetate and periodic acid. Thus inertness to periodic acid or lead tetraacetate should not always be considered evidence for the absence of l,%-glycolgroupings. The ability of boric acid to react with glycols to form complexes has also been of value in structure determination. A detailed review of the literature is provided by B O e ~ e k e n . ~Again ~ a cis relationship of the hydroxyl groups, when fixed in a semi-rigid ring, is necessary to permit reaction. A very interesting and significant application of borate complexes to the separation of sugars is described by Khym and 2i11.44 (41a) R. M.Hann and C. S. Hudson, J . Am. Chem. SOC.,66, 1909 (1944). (41b) L.J. Heidt, E. K. Gladding and C. B. Purves, Paper Trade J., 121, No. 9, 35 (1946). (42) R. J. Dimler, H. A. Davis and G . E. Hilbert, J . Am. Chem. Soc., 68, 1377 (1946); B. H. Alexander, R. J. Dimler and C. L. Mehltretter, ibid., 73, 4658 (1951). (43) J. Boeseken, Advances in Carbohydrate Chem., 4, 189 (1949). (44) J. X. Khym and L. 1'. Zill, J . Am. Chem. Soe., 73, 2399 (1951);74, 2090 (1952).
15
RELATIVE REACTIVITIES O F HYDROXYL GROUPS
Borate complexes of sugars are placed on anion exchangers and eluted with boric-borate buffers. Separation of disaccharides from monosaccharides and of the components of hexose and pentose mixtures has been realized. The results obtained could be explained on the basis of the proposed structures for these cornplexe~,~~ in which an equilibrium prevails among the three complexes XXXVII, XXXVIII, and XXXIX. The properties of these complexes have been by considering changes in optical rotation at different borate and sugar concentrations. Different sugars appear to form a varying number of complexes. FuranI
-C-OH
-&-OH
- L O
\ -C--0 ! /
I XXXVII
XXXVIII
H+
-c-0
+ 2Hz0
o-cXXXIX
ose-pyranose interconversions are believed to be of primary importance in the extent of complexing with boric The observed order of elution of the sugars from anion exchangers is interpreted on this basis. Rose and S c h ~ e i g e r have t ~ ~ been able to separate ribosides from a mixture containing free purine and pyrimidine bases and desoxyribosides by forming borate complexes of the ribosides and then chromatographing on paper. The ribosides do not migrate in this form. Borate complexes have been utilized by Brigl and G ~ - i i n e rto~ ~effect partial esterification. Anhydrous D-glucose and metaboric acid dissolved in acetone give a complex which exhibits the arialysis of a diborate. Reaction of the latter with an excess of benzoyl chloride gives 2,6-di-0benzoyl-D-glucose (XL). D-Mannitol likewise forms a diborate, which produces the lJ6-di-0-benzoyl derivative (XLI) upon ben~oylation. In the presence of boric acid, D-glucose diethyl thioacetal yields the 6-benzoate (XLII). In the non-aqueous medium the formation of complexes (45) H. S. Isbell, J. F. Brewster, Nancy B. Holt and Harriet L. Frush, J . Research Matl. Bur. Standards, 40, 129 (1948). (46) I. A. Rose and B. S. Schweigert, J . A m . C'henh. SOC.,73, 5903 (1951). (47) P. Brigl and H. Griiner, Ann., 496, 60 (1932).
16
JAMES M. SUGIHARA
of the types XXXVIII and XXXIX would be suppressed. However, the spatial requirements of hydroxyl groups favoring complexing would not be expected to be altered appreciably. Although these ideas seem pertinent, there still remains the possibility that the role of boric acid in the benzoylation of the thioacetal may be incidental, since selective
g.. c!
CHiOBs HObH
H OBa
HobH
HO H
HC (SC2Hd2 HAOH HobH
HAOH
HAOH
HAOH
HbOH
HdoH
HCOH
AHzoBs XL
LH20Bz XLI
1
&HIOBI XLII
esterification of this compound has been demonstrated to occur in the absence of boric acid to yield XLII (see p. 35). Richtmyer and Hudson48 have found that the rotation of several polyols is augmented in an acidified ammonium molybdate solution, and to a much greater extent than in borate solutions. Addition compounds of sugars and sodium bisulfite are reported by S ~ n d m a n . The ~ ~ rate of decomposition of these substances is primarily determined by the arrangement of hydroxyl groups. When the relationship is trans, more rapid decomposition is noted than when cis. The remainder of the molecule has little effect, although there is also a correlation between the rate of mutarotation and the value of the equilibrium constant. These observations are suggestive of a type of complexing similar to that of the borates.
111. SELECTIVE ETHERIFICATION The most widely recognized method of selective etherification of sugars and polysaccharides involves the reaction of primary alcohol groups with triphenylmethyl (trityl) chloride. HelferichS0has described the selective character of this reagent, whose rate of reaction with primary hydroxyl groups is many fold that with secondary groups. Other etherification reagents have been found to be, by and large, less specific toward primary and secondary alcohol groups, and thus selective (48) N. K. Richtmyer and C. S. Hudson, 3. Am. Chem. Soc., 73, 2249 (1951). Much of the extensive earlier literature is there cited. (49) J. Sundman, Finnish Paper Timber J., 81, 187 (1949); Chem. Abstracts, 46, 2204 (1961); Suomen Kemistilehti, 24, 3 (1951); Chem. Abstracts, 46, 2502 (1952). (50) B,Helferich, Advances in Carbohydrate Chem., 3, 79 (1948).
RELATIV& REACTIVITIES O F HYDROXYL GROUPS
17
reaction is more dependent upon the experimental conditions involved. The usual etherification reaction is carried out in an alkaline medium and thus the effect of the alkali on the hydroxyl compound is of importance ; accordingly, this aspect will be considered in this section.
I I
--COH-MOH
or - -OM
I
RX --t
I
-C-OR
I
+ MX
M = any metal; RX = an ester of an inorganic acid
1. Methyl Ethers One of the very important applications of the methyl ethers of sugars and polysaccharides has been in structure determination and for this purpose the complete substitution of all free hydroxyl groups of a given substance is required. Bourne and Peats1 have provided a full description of the principles, reagents, and conditions that are involved. I n contrast with the usual complete methylation, a selective methylation of certain hydroxyl groups has been accomplished by direct reaction (as differing from methods requiring blocking groups and their subsequent removal) in a limited number of cases. Monomeric sugar derivatives will be considered first, to be followed by polysaccharides, since with the latter there are factors involved which introduce complications. In those reactions in which little selectivity is exhibited, of which methylation is an example, refined methods of separation of the products of an incomplete reaction may be of material value. The resolution of complex mixtures is often possible by chromatographys2 when the classical procedures of organic chemistry fail. Differential adsorption on activated carbon is another of the newer methods.62n PacsuSzbobtained 2-O-methyl-~-glucose by the direct methylation of 5,6-0-isopropylidene-~-glucosedibenzyl thioacetal, with subsequent hydrolysis. Lieser and L e c k s y ~ k later ~ ~ reported the 2-0-methyl (51) E. J. Bourne and S. Peat, Advances in Carbohydrate Chem., 6, 145 (1950). (52) For general reviews see W. W. Binkley and M.L. Wolfrom, “Chromatography of Sugars and Related Substances,” Sugar Research Foundation, Inc. (New York), Scientific Reports Ser., No. 10,33 pp., August (1948);L. Zechmeister, “Progress in Chromatography, 1938-1947,” John Wiley and Sons, Inc., New York, 1950; H. G. Cassidy, 1 L Adsorption and Chromatography,” Vol. V, of “Technique of Organic Chemistry,” A. Weissberger, editor, Interscience Publishers, Inc., New York, 1951; R. J. Block, R. LeStrange and G. gweig, “Paper Chromatography, a Laboratory Manual,” Academic Press, Inc., New York, N. Y., 1952; “ A Guide to Filter Paper and Cellulose Powder Chromatography,” H. Reeve Angel and Co., Ltd., London, 1952. (52a) R. L. Whistler and D. F. Durso, J . Am. Chem. SOC.,73, 677 (1950). (52b) E. Pacsu, Ber., 68, 1455 (1925);66, 51 (1932);E.J. Bourne and S. Peat, Advances in Carbohydrate C h m . , 6, 149 (1950). (53) T. Lieser and E. Leckzyck, Ann., 611, 137 (1934).
18
JAMES M. SUOIHARA
derivative of D-glucose diethyl thioacetal (XLIII) and the analogous derivative of the dibenzyl thioacetal by a direct reaction with silver oxide and methyl iodide. It is of interest to note that their procedure fails HC (SCaHs)a
HC (SC2H5) o HbOH
I~LOCHI
+ CHsI-
AgZO
HobH
t:
HO H
to yield the expected products with the diethyl and dibenzyl thioacetals of D-galactose, L-arabinose, and L-rhamnose as well as with the dibenzyl thioacetal of ~-xylose.63 Papadakiss4 found that by the reaction with methyl iodide of a monosodium derivative of D-glucose diethyl thioacetal, obtained earlier by Fischer66 through treatment of the thioacetal with sodium ethoxide, a crystalline monomethyl ether of D-glucose diethyl thioacetal could be obtained; the melting point would indicate this compound to be the 2-0-methyl ether (XLIII). Percival and coworkers66 prepared complexes of sugars with alkalies and then formed methyl ethers by reaction with dimethyl sulfate. Methyl a- and 8-D-gluCopyranosides yield methyl mono-0-methyl glucopyranosides (XLIV), identified by conversion to 6-O-methyl-~-glucosephenylosazone (XLV) Application of the same procedure to maltose, followed by hydrolysis, produces 2-0-methyl- and 2,6-di-O-methyl-~-glucose. In like fashion sucrose gives 6-0-methyl-~-glucose phenylosazone (XLV), and lactose
.
7
HCOCHs
r-
CHIOCH
HboH
c:
H 0 -
HKl
HC=N-NHPh A=N--NHPh
HAOH H oAH
C(H)OCH,
or
HoAH HAOH HAOH H 0--
c:
+Ho H
L
+HO H
HAOH
HboH
HA0
HLOH
(54) P. E. Papadakis, J. Am. Chem. Soc., 62, 3465 (1930). (55) E.Fischer, Ber., 27, 673 (1894). (56) W.J. Heddle and E. G . V. Percival, J. Chem. Soc., 1690 (1938);E. G . V. Percival, ibid., 1160 (1934);648 (1935);E. G. V. Percival and G. G.Ritchie, ibid., 1765 (1936).
RELATIVE REACTIVITIES OF HYDROXYL GROUPS
19
forms 2-0-methyl- and 2,4-di-O-methyl-~-galactose. The position of the alkali in the complex is inferred to be that one upon which methylation occurs. Purdie and Irvine6' treated methyl a-D-ghcopyranoside with methyl iodide and silver oxide and obtained a product which was believed to be methyl 2,3,4-tri-0-rnethyl-c-~-glucoside. However, the hydrolysis and subsequent oxidation with nitric acid failed to yield a crystalline tri-0-methylsaccharic acid. The total substitution of secondary hydroxyl groups without any appreciable reaction of the primary hydroxyl would appear to be improbable. The methylation of methyl a-D-glucopyranoside with methyl iodide in the presence of thallous hydroxide by Barker, Hirst, and J o n e P yielded a mixture of tri-0-methyl derivatives in which substitution in the two and six positions predominated. Fear and Menziessg had earlier demonstrated the formation of a trithallium derivative from methyl a-D-glucopyranoside and thallous hydroxide. The complex reactions of alkalies with reducing sugars have been described extensively. The origin of the initial products that are obtained is usually explained by the classical Lobry de Bruyn and Alberda van Ekenstein transformation,s0 in which an enediol (XLVI) is proposed as the key intermediate. In recent studies Sowden and Schafferel used D-glu~ose-l-c~~, ~-fructose-l-C'~, and D-glucose in DzO to CHOH = I1 HAOH HCOH CHO
I
I
=
I
CHO
HOCH I
XLVI
lt
CHZOH
I I
C=O
study this reaction, applying a radioisotopic dilution analysis for D-glucose and D-fructose. Contrary to some of the other recent findings, which are discussed in their articles, their results could be interpreted in terms of the classical mechanism for this reaction. The observed acidic character of any reducing sugar is also explainable on the basis of the acidic (57) T. Purdie and J. C. Irvine, J. Chem. Soe., 83, 1021 (1903). (58) C. C. Barker, E. L. Hirst and J. K. N. Jones, J. Chem. SOC.,1695 (1938). (59) Christina M. Fear and R. C. Menaies, J. Chem. SOC.,937 (1926). (60) C. A. Lobry de Bruyn and W. Alberda van Ekenstein, Ree. Irav. chdm., 14, 156, 203 (1895); 16, 92 (1896); 16, 257, 262, 274, 282 (1897); 18, 147 (1899); 19, 5 (1900). These (61) . . J. C. Sowden and R. Schaffer, J . Am. Chem. SOC.,74,499,505 (1952).
articles cite other references.
20
JAMES M. SUOIHARA
enol. Conductometric measurements have shown that reducing sugars behave as weak dibasic acids ;az however, conductometric and polarographic r n e a s u r e m e n t ~indicate ~ ~ ~ ~ ~ acidity and complex formation in nonreducing sugars, such as sucrose. Since an analogous enol would not be possible in these compounds or in glycosides, the observed acidic properties might be the result of a permanent polarization. This may serve to explain the observed high reactivity of the hydroxyl group on carbon atom 2 in an alkaline medium.
I
A much more extensive investigation of the effect of alkalies has been made in the case of polysaccharides, especially cellulose; this is understandable in view of the industrial importance of mercerization, of the viscose process, and of cellulose ethers. Various complexes have been reported for cellulose and alkalies depending upon the nature of the alkali, upon its concentration, upon the washing treatment used, and upon the pretreatment of the cellulose. A discussion of this subject has been published by Nicoll and C ~ n a w a y . There ~~ is general agreement on the formation of several compounds, which are susceptible to hydrolysis. The question as to whether these compounds are molecular complexes (XLVII), true alkoxides (XLVIII), or an equilibrium mixture of the two has not been answered. In recent studies Lauere6has reached --(!LOH.NaOH
I XLVII
-A-ONa
I
+ HzO
XLVIII
the conclusions that aqueous sodium hydroxide forms complexes with the hydroxyl groups in positions two and three of the amorphous portions of cellulose, and that the base can attack only the hydroxyl group in position two of the semicrystalline region (on the surface of the crystalline region). Assaf, Haas, and Purvese6in an earlier investigation have suggested that the unavailability of the primary hydroxyl group on carbon atom 6 is a (62) P. Hirsch and R. Schlags, 2.physik. Chem., 141, 387 (1929). (63) P. M. Strocchi and E. Gliozzi, Ann. ehzm. (Rome), 41, 689 (1951); Chem. Abstracts, 46, 4826 (1952). (64) W. D. Nicoll and R. F. Conaway in “Cellulose and Cellulose Derivatives,” E. Ott, editor, Interscience Publishers, Inc., New York, 1943, p. 709. (65) K. Lauer, Makromol. Chem., 7, 5 (1951); Kolloid-Z., 121, 33, 36, 137 (1951). (66) A. G. Assaf, R.H. Haas and C. B. Purves, J . Am. Chem. SOC.,66,66 (1944).
RELATIVE REACTIVITIES OF HYDROXYL GROUPS
21
result of its strong hydrogen-bonding capability. Alkali complexes have also been described for starch,67amylose,68inulin,6s(b)and glyc0gen.6~ The location of the alkali in these complexes has been inferred from the results of a subsequent methylation reaction. A sodium hydroxide cupricellulose is methylated to yield a product containing 0.8 t o 0.9 methoxyl per anhydro-D-glucose unit.70 The latter upon hydrolysis yields a mono-0-methyl-D-glucose, believed to be 3-O-methyl-~-glucose, and unsubstituted D-glucose. Heddle and Percival7’ repeated this investigation and were able t o isolate 2-@methyl-~-glucose and 3-0methyl-D-glucose in the form of the phenylhydrazone (XLIX) and the osazone (L), respectively. In these and subsequent investigations in which acid hydrolysis is involved, the possible cleavage of any 6-methyl ether groups should be kept in mind, in view of the observation by Ohle and Tessmar71athat, although this linkage is more resistant to hydrolysis than the glycosidic bond, it is subject to rupture under more drastic conditions. Heddle and Percivale8@) also obtained %O-methyl-~-glucose from amylose and cellulose treated with alcoholic potassium hydroxide, followed by methylation and hydrolysis. L i e ~ e r ?was ~ able to obtain 2-O-methyl-~-glucose, characterized as its phenylhydrazone (XLIX), from the hydrolysis of a methylated cellulose containing approximately one methoxyl group per anhydro-D-glucose unit. Hess and coworker^'^ hydrolyzed an O-methylcellulose, containing approximately 0.5 methoxyl per anhydro-D-glucose unit, and obtained D-glucose and %O-rnethyl-~glucose; a smaller quantity of either 3- or 6-O-methyl-~-glucose was indicated. In similar work Gaver and report the preparation of uniformly 2-substituted glucopyranose polymers. Using Gaver’s general procedure, Sugihara and W~lfrorn’~ obtained a monomethylcellulose, which was methanolyzed, hydrolyzed, and allowed to react with ethyl mercaptan. The diethyl thioacetal was chromatographed to obtain crystalline 2-O-methyl-~-glucose diethyl thioacetal, with no (67) (a] K. M. Gaver, U. S. Pat. 2,397,732 (Apr. 2, 1946); U. S. Pat. 2,518,135 (Aug. 8, 1950); K. M. Gaver, Esther P. Lasure and D. V. Tieszen, U. S. Pat. 2,572,923 (Oct. 30, 1951); (b) Olga Yovanovitch, Compt. rend., 232, 1833 (1951). (68) (a) W. J. Heddle and E. G. V. Percival, J. Chem. Soc., 1690 (1938); (b) P. Karrer, M. Staub and A. Wiilti, Helv. Chim. Acta, 6, 129 (1922). (69) P. Karrer, Hetv. Chim. A d a , 4, 994 (1922). (70) W. Traube, R. Piwonka and A. Funk, Ber., 69, 1483 (1936); R. Piwonka, ibid., 1965. (71) W.J. Heddle and E. G. V. Percival, J. Cheni. Soc., 249 (1939). (71a) H. Ohle and K. Tessmar, Ber., 71, 1843 (1938). (72) T . Lieser, Ann., 470, 104 (1929). (73) K. Hess, C. Trogus, W. Eveking and E. Garthe, Ann., 606, 260 (1933). (74) J. M. Sugihara and M. 1,. Wolfrom, J . Ant. Chem. Soc., 71, 3509 (1949).
JAMES M. SUGIHAFlA
22
other crystalline compounds isolable. Karrer and EscheP hydrolyzed a highly methylated cellulose (42.5-43% ’ methoxyl) and obtained a di-0-methyl-D-glucose, isolated as the crystalline methyl 2,3-di-0methyl-4,6-di-O-tosyl-cw-~-glucopyranoside @I). HC=N-NHPh
A
H OCHs HobH
7
HC=N-NHPh
H OCHs
A=N--NHPh
HAOCH,
CHadH
CH,dH
HAOH
HAOH
HLTs
HAOH
HLOH
H 0 -
(!2H20H XLIX
AHaoH L
c:
AHaOTs
LI
These investigations are striking in showing a lack of reactivity of the six position in contrast t o analogous reactions with monomeric compounds, such for example, as a methyl glucopyranoside (see p. 18). A possible explanation for this observation has been suggested, based upon alkylation reactions in quaternary ammonium bases. Compton7*found that cellulosic materials are dispersed in quaternary ammonium bases as microscopic particles. Mahoney and P ~ r v e shave ~ ~ compared the reactivity of primary and secondary hydroxyl groups of cellulose in caustic and in quaternary ammonium bases. With the latter, the primary hydroxyl groups are approximately twice as reactive. In caustic solutions the reactivity of the secondary hydroxyl groups is dependent upon the alkali concentration; increased reactivity is observed with increased alkali concentrations. These observations are suggestive that the hydroxyl group of cellulose at position 6 is unreactive because of a strong hydrogen b ~ n d , ~which ? , ~ remains ~ intact in a topochemical and heterogeneous reaction. It is of interest to note that alkylation of cellulose in quaternary ammonium bases leads to the formation of watersoluble products, which have a low degree of substitution. Bock?*attributes this difference to a random substitution which is believed to be possible because of a greater accessibility factor. In addition to increasing the rate of the alkylation reaction, increased alkali concentrations favor, and indeed are necessary to achieve, a high degree of substit~tion.7~Completeness of reaction may require a higher alkali concentration in order (75) P.Karrer and E. Escher, Helv. Chim. Acta, 19,1192 (1936). (76) J. Compton, J Am. Chem. Soc., 60,2823 (1938). (77) J. F.Mahoney and C. B. Purves, J. Am. Chem. Soc., 64, 15 (1942). (78) L. H. Bock, Znd. Eng. Chem., 29,985 (1937). (79) E.J. Lorand, Znd. Eng. Chem., 31, 891 (1939).
RELATIVE REACTIVITIES O F HYDROXYL GROUPS
23
to permeate the more lyophobic cellulose derivative*O formed upon partial alkylation. Spurling' has made a mathematical analysis of substituents in methylcellulose and found a statistical distribution based upon the relative reactivities of the three hydroxyl groups. 2. Other Ethers Many other ethers of carbohydrates have been prepared and described; among these the more common additional ones are the following: ethyl, benzyl, hydroxymethyl, hydroxyethyl, allyl, and cyanoethyl ethers. In the vast majority of the cases complete or nearly complete substitution of the hydroxyl groups was effected. In other instances partial substitution was obtained, but often little or no information was supplied concerning the location of substituents. Investigations of these types will be mentioned briefly, in order mainly to indicate the extent of the information that is available. The distribution of ethoxyl groups in a technical ethylcellulose, containing 2.48 ethoxyl per anhydro-D-glucose unit, was studied by Mahoney and Purves.82 Lead tetraacetate oxidation, as well as tosylation and iodination, was utilized to locate free hydroxyl groups. For a total of 0.52 (ie., 3.00 - 2.48 = 0.52) free hydroxyl per anhydro-D-glucose unit, only 0.12 mole is located in position 6, and 0.14 in position 2, but 0.26 is present in position 3. Using the same approach, Dyer and Arnolds3 determined the distribution of hydroxyl groups in a carboxymethylcellulose. The extent of substitution at the primary (ie., 6) position is nearly equal to the sum of substitutions at the secondary positions. The periodate oxidation of a 2-cyanoethyl ether of starch, of degree of substitution of approximately 1.1, indicated that substitution is predominantly in the 6-positions4 (LII). These three confirm the anticipated high reactivity of the primary hydroxyl group at the 6-position; in addition, the research of Mahoney and Purves82 clearly demonstrates that the reactivity of the hydroxyl group at the 2-position greatly exceeds that of the hydroxyl group at the 3-position. The course of heterogeneous benzylation of cellulose was followed microscopically by Lorand and GeorgilS6who found that a topochemical (80) G. G. Johnston, J. Am. Chem. Soc., 63, 1043 (1941). (81) H. M. Spurlin, J . Am. Chem. Soc., 61, 2222 (1939). (82) J. F. Mahoney and C. B. Purves, J . Am. Chem. Soc., 64, 9 (1942). (83) Elizabeth Dyer and H. E. Arnold, J . Am. Chem. Soc., 74, 2G77 (1952). (84) 0. A. Moe, S. E. Miller and Marjorie I. Buckley, J . Am. Chem. Soc., 73, 4185 (1951). (85) E. J . Lorand and E. .4.Georgi, .I. Am, Chem. Soc., 69, 1166 (1937),
24
JAMES M. SUQIHARA
reaction occurs, with no observable selectivity. Gomberg and Buchlers6 were able to carry out partial benzylation of methyl a-D-glucopyranoside, sucrose, starch, and cellulose but in no case was any preferential reactivity of any type of hydroxyl group noted. Tomecko and Adamsg7 have reported partially substituted allyl ethers of sucrose, inulin, starch, and
(R
a
-CH,CH&N) LII
cellulose. The location of the allyl group in the resulting products was not ascertained. The 2-cyanoethyl ethers of varying degrees of substitution of a guar galactomannan were subjected to periodate oxidation.88 The results that were obtained are indicative of a random distribution of the cyanoethyl grouping.
IV. SELECTIVE ESTERIFICATION AND HYDROLYSIS 1. Tosyl and MesyP9Esters
Sulfonic acid esters of carbohydrates have been extensively studied. No attempt will be made to review the entire literature.898 Only those investigations which make a significant contribution in illustrating the selective nature of sulfonylation as well as those in which the selective cleavage of sulfonic esters is concerned, will be considered. The selective tosylation of primary hydroxyl functions, leaving secondary groups untouched, has been described many times. Compton obtained the 6-0-tosyl derivatives (LIII for the a-anomer) of methyl a- and P-D-glucopyranosidesgowith tosyl chloride and pyridine. I n a similar manner, preferential tosylation of the primary hydroxyl groups (86) M. Gomberg and C. C. Buchler, J. Am. Chem. Soe., 43, 1904 (1921). (87) C. G . Tomecko and R. Adams, J. Am. Chem. Soe., 46,2698 (1923). (88) 0. A. Moe, S. E. Miller and Marjorie I. Buckley, J. Am. Chem. SOC.,74, 1325 (1952). (89) Tosyl = p-toluenesulfonyl;mesyl = methanesulfonyl. (89a) See the comprehensive review by R. S. Tipson, this vol., p. 107. (90) J. Compton, J. Am, Chem. Soc., 60, 396 (1938).
25
RELATIVE REACTIVITIES O F HYDROXYL GROUPS
of methyl @-cellobiosideglis realized even more readily than in the cases
AI
H 0 CHzOTs
LIII
of the a- and p-D-glucopyranosides. 2,4-O-Benzylidene-~-glucitol yields the 1,G-di-0-tosyl derivative (LIV) when treated with tosyl chloride and p ~ r i d i n e . ~Selective ~ mesylation has also been shown to occur in the same way. Helferich and coworkerss3prepared methyl 6-O-mesyl-a-~glucopyranoside, methyl 6,6'-di-O-mesyl-/3-cellobioside (LV), and 6-0mesyltrehalose (LVI). Tritylation is found to be specific in its reactivity toward primary hydroxyl and dependent on the nature of the hydroxyl compound in the same manner as t o s y l a t i ~ n . ~ ~ H
CH,OMs
OH
CHZOTs
I
H7°1
H
OH
HoyHAcHph HCO I I
HCOH
CHiOMs
LV
v
CH~OMS
OH
CHsOTs
LIV H LVI (91) J. Compton, J . Am. Chem. SOC.,60, 1203 (1938). (92) .L. v. Vargha, Ber., 68, 1377 (1935). (93) (a) B. Helferich and A. Gniichtel, Ber., 71, 712 (1938); (b) B. Helferich and F. von Stryk, ibid., 74, 1794 (1941). (94) B. Helferich, Advances i n Carbohydrate Chem., 3, 79 (1948); I. Sakurada and T. Kitabatake, J. SOC.Chem. I d . , Japan, 37, suppl. binding, 604 (1934). (95) R. C. Hockett, H. G. Fletcher, Jr., and J. B. Ames, J. Am. Chem. Soc., 63, 2516 (1941); R. C. Hockett and M. L. Downing, ibid., 64, 2463 (1942).
J A M E S M. SUGIHARA
26
The selective tosylation and mesylation of sugars with reducing groups have also been realized. 6-O-Tosyl-~-g~ucose,~~ 1,6-di-O-tosyl-Dfructose (LVII),87 2,3-0-isopropylidene-5-O-tosyl-~-rhamnose (LVIII) ,98 and 6 - ~ - m e s y ~ - ~ - g ~ uhave c o s ebeen ~ ~ prepared. By the reaction of two
rYHoH
CHzOTs &=O
HOt'H IIbOH I
H~OH
&HnOT8
AH3
LVII
LVIII
moles of tosyl chloride in pyridine upon D-glucose, followed by acetylation, Hardegger, Montavon, and Juckeriooobtained crystalline 1,3,4-triO-acetyl-2,6-di-O-tosyl-a-~-glucose (LIX) as the principal product accompanied by 1,2,3,4-tetra-0-acety~-6-0-tosy~-~-~-g~ucose (LX) and a little 1,3,4-tri-0-acety~-2,6-d~-~-tosyl-~-~-glucose (LXI). These results again D-Glucose
-
+ 2 p-CH&,,H4S0&l CrHsN, AczO
bHaOTs LIX
bHnOTs LX
1
CH~OTS LXI
indicate the unusual reactivity of the hydroxyl group of position 2 as compared with that of the other secondary hydroxyl groups. One of the most important of the properties of tosyl esters is the ease of cleavage of those derived from primary alcohols. In this regard the formation of an iodo compound by reaction with sodium iodide in (96) E.Hardegger and R. M. Montavon, Helv. Chim. Acta, 29, 1199 (1946). (97) W. T.J. Morgan and T. Reichstein, Helv. Chim. Acta, 21, 1023 (1938). (98) P.A. Levene and J. Compton, J . B i d . Chem., 116, 169 (1936). (99) B. Helferich, H. Dresaler and R. Griebel, J . prakt. Chem., 165, 285 (1939). (100) E.Hardegger, R. M. Montavon and 0. Jucker, Helv. Chim.Acta, 51, 1863 (1948).
RELATIVE REACTIVITIES O F HYDROXYL GROUPS
27
acetone has had wide application.lol It should be noted that replacement of secondary tosyloxy groups has been shown to occur in some cases, for example, 2,5-di-O-tosyl-l,4 :3,6dianhydro-~-mannitol (LXII) and 2,5di-0-tosyl-1,4:3,6-dianhydro-~-glucitol(LXIII).ls~a)~(b) However, the conditions necessary to effect reaction were more drastic. Wiggins and Wood102found that the reactivity of secondary tosyl and mesyl
LOLH, LXII
(--OhHz LXIII
groups toward replacement by halogen is dependent upon the stereochemistry of the hexitol. A primary tosyl ester with an adjacent free hydroxyllo3or with an adjacent second tosyl grouping,lo4when treated with sodium iodide, may give rise to a double bond between the carbon atoms concerned. The iodo derivative is a useful intermediate for the preparation of a wide variety of different types of compounds. Primary mesyl esters also react with sodium iodide in acetone, but the selectivity of this cleavage is less because of the greater reactivity of secondary mesyl ester^.^^(^) Methyl 2,3,4-tri-0-acetyl-6-o-mesyl-ce-~-glucopyranos~de is converted with acetic anhyinto methyl 2,3,4,6-tetra-0-acetyl-cu-~-glucopyranoside dride and potassium acetate. Replacements of a primary mesyloxy group with fluorine by use of potassium fluoride in methanol,lo5with chlorine by use of lithium chloride,'02 and with pyridine to form a pyridinium deoxy derivative, Io6 have been reported. Primary tosyloxy groups have been replaced by hydrogen,106aby thiocyanate, lo7 and by (101) J. W. H. Oldham and Jean K. Rutherford, J. A m . Chem. Soc., 64, 366 (1932); K. Freudenberg and K. Raschig, Ber., 60, 1633 (1927). (102) L. F. Wiggins and D. J. C. Wood, J . Chenz. Soc., 1180 (1951). (103) D. J. Bell, E. Friedmann and S.Williamson, J. Chem. Soc., 252 (1937). (104) R. M. Hann, A. T. Ness and C. 8. Hudson, J. AWL.Chem. Soc., 66,73 (1944). (105) B. Helferich and A. Gnuchtel, Ber., 74, 1035 (1941); B. Helferich and M. Vock, ibid., 1807. (106) B. M. Iselin and J. C. Sowden, J. A m . Chem. Soc., 73, 4984 (1951). (106e) H. Schmidt and P. Karrer, Helv. Chim. Acta, 32, 1371 (1949). (107) A. Muller and A. Wilhelms, Ber., 74, 698 (1941).
28
JAMES M. SUOIHARA
ammonia and amines,lo8 either directly or through' an intermediate anhydro derivative (see p. 8 for mechanism of anhydro formation). Other substituents may be introduced via the latter. Replacement of secondary tosyloxy groups with ammonia and amines is also possible.109 The removal of secondary tobyl groups is difficult and is usually attended with complications, although the reductive c1eavage"O with sodium amalgam proceeds smoothly. Alkaline hydrolysis occurs with more difficulty, and frequently inversions are observed. Ohle and coworkers"' HHO OTs i T l
NLOM:!
I
o
+HfJ
I
1
I
concluded that alkaline methanolysis of tosyl esters having an adjacent hydroxyl group in the trans position leads to compounds containing ethylene oxide rings. These inversion reactions have been extensively utilised in the synthesis of rare sugars from those readily available. This neighboring-group participation has been found t o apply to groups other than unsubatituted hydroxyls. Winstein, Hess, and Buckles112 found that trans-2-acetoxycyclohexyl p-toluenesulfonate (LXIV) is converted into the diacetate (LXV) with retention of configuration. A neighboring trans-acylamino group may participate in a CHI
LXIV
CHa
LXV
aimilar manner.Il8 When there is no trans neighboring group t o a (108) S. N. Danilov and I. 6. Lishanskii, Zhur. Obschl Khim., 21, 366 (1951); Chern. Abstracts, 46, 7529 (1951); H.Ohle and L. v. Vargha, Ber., 61, 1203 (1938); H. Ohle and E. Euler, ibid., 69, 1022 (1936);H.Ohle, E. Euler and W. Malerczyk, z%id., 1636;H. Ohle, H.Friedeberg and G. Haeseler, ibid., 2311. (109) K. Freudenberg, 0. Burkhart and E. Braun, Ber., 69, 714 (1926);E. W. Bodycote, W. N. Haworth and E.L. Hirst, J . Chem. Soe., 151 (1934). (110) K.Hess and K. E. Heumann, Ber., 72, 149 (1939). (111) H.Ohle and C. A. Schultz, Ber., 71, 2302 (1938);and earlier papers in that
series. See also reference 22. (112) S. Winstein, H. V. Hess and R. E. Buckles, J . Am. Chem. Soc., 64, 2796 (1942). (113) G. E. McCasland, R. K. Clark, Jr. and H. E. Carter, J . A m . Chem. SOC., 71, 637 (1949);S. Winstein and R. Boschan, ibid., 72, 4669 (1950).
RELATIVE REACTIVITIES O F HYDROXYL GROUPS
29
secondary tosyl ester function or any other group permitting ring formation, cleavage is usually much more difficult t o effect;114this hydrolysis appears to occur without any Walden inversion. 116 I n reactions in which complete tosylation is desired, unexpected products may sometimes result. Hess and Stensel"" found that although methyl 4-0-acetyl-2,3di-0-tosyl-~-~-glucopyranoside gives the expected 2,3,6-tri-O-tosyl derivative when it reacts with tosyl chloride and pyridine, the a-anomer forms the 6-chloro-6-deoxy derivative (LXVI) instead. Methyl a-D-glucopyranoside can yield the tetra-0-tosyl derivative under suitable conditions, but at a higher temperature a tri-0-tosyl monochloro or a di-0-tosyl dichloro derivative can be obtained. Pyridine hydrochloride in pyridine was shown to convert the tetra-0-tosyl or the tri-0-tosyl-monochloro compound into the dichloro substance LXVII by replacement of tosyloxy groups; the chlorine atoms are attached at the 4 and 6 positions. Bernoulli and Stauffer"' found that an excess of tosyl chloride in the presence of pyridine will react with D-glucose t o form tetra-0-tosyl-D-glucosyl chloride.
r---
HCOCHI
H AOTs TsOAH
H L O Ac
c!I
H 0CH2C1
LXVI
A very important application of the replacement of primary tosyloxy groups by iodine atoms from sodium iodide is in the determination of the distribution of substituents in cellulose derivatives. Mahoney and PurvesB2were able to determine the degree of substitution of the 6 position in a technical ethylcellulose by this method (see page 23). Lead tetraacetate and periodate oxidations of the ethylcellulose, the ethyl 0-ethyl-D-glucopyranosides formed by ethanolysis, and the free sugars formed by hydrolysis, indicate the extent of substitution of the hydroxyl groups in the 2 and 3 positions. This technique permits a more exact method of determining the distribution of substituents than the classical (114) A. Muller, Maria Morioz and G. Verner, Bet-., 72,745 (1939);D.J. Bell and S. Williamson, J . Chem. SOC.,1196 (1938). (115) G.J. Robertson and D. Gall, J . Chem. Soc., 1600 (1937). (116) K.Hess and H. Stenzel, Bcr., 68, 981 (1935). (117) A. I,. Bernoulli and H. Stauffer, Helv. Chim. Ada, 23, 615 (1940).
30
JAMES M. SUGIHARA
method of hydrolysis and separation of the resulting products. The techniques, which have been applied for the latter procedure, have yielded semi-quantitative results only. In addition, Mahoney and PurvesS2 made kinetic measurements and found first-order rate constants for tosylation in the approximate ratio of 15 for position 6, 2.3 for position 2 and 0.07 for position 3. In the same manner an acetone-soluble cellulose acetate was tosylated and the comparative rate constants determined and found to be 23, 2.2, and 0.11 for positions 6, 2, and 3, respectively.”* The suppressed reactivity a t position 3 may be a steric effect.11g A group present in position 2 may markedly inhibit the entrance of the relatively large tosyl group. The group present may also exert a deactivating effect on the unsubstituted hydroxyl group. Starch has been tosylated and iodinated to form a di-0-tosyl-monoiodo derivative. However, Dumazert121found that starch treated with sodium hydroxide is more difficult to tosylate and one primary hydroxyl group in seven D-glucose units appears to be blocked. The tosylation-iodination and periodate oxidation procedures were applied to carboxymethylcellulose by Time11122 and by RydholmlZ3without success, but were found t o be applicable in the hands of Dyer and Arnold.83 Tasker and P ~ r v e s were ’ ~ ~ not able to determine the distribution of substituents in a commercial hydroxyethylcellulose by this method because the iodination reaction resulted in a loss of combined tosyl and halogen substituents. A possible explanation for this observation is based upon the formation of a cyclic compound of the type illustrated by LXVIII. 1
0-
bH, ‘OTs
HbOIbHo
bH
\ 0-CH2 I
\-
LXVIII
(118) (a) T. S.Gardner and C. B. Purves, J . Am. Chem. SOC.,64, 1539 (1942);(b) F. B. Cramer and C. B. Purves, ibid., 61,3458 (1939). (119) W.W.Pigman and R. M. Goepp, Jr., “Chemistry of the Carbohydrates,” Academic Press, Inc., New York, 1948,p. 549. (120) K. Hess and R. Pfleger, Ann., 607, 48 (1933). (121) C. Dumaaert, BuU. soe. chirn. bioZ., 32, 983 (1950). (122) T. Timell, Suensk Papperstidn., 63, 61 (1949); Chem. Abstracts, 43, 4849 (1949). (123) S. Rydholm, rSoensk Papperstidn., 63, 561 (1950);Chem. Abstracts, 46,5403 (1951). (124) C.W.Tasker and C. B. Purves, J . Am. Chem. SOC.,71, 1023 (1949).
RELATIVE REACTIVITIES OF HYDROXYL GROUPS
31
2. Xanlhution
Interest in the xanthates of carbohydrates has arisen almost entirely through the importance of the viscose process in the technical production of rayon and related products.12s The selective character of the reaction of carbon disulfide and alkali with polyhydroxy compounds has been studied. Lieser and Nage112efound that a monoxanthate is formed with polyhydric alcohols and methyl a-D-glucopyranoside when they react with carbon disulfide and aqueous barium hydroxide. The xanthation that has been demonstrated in the cases of glycerol 1,3-dimethyl ether and levoglucosan (LXIX) shows that secondary hydroxyl groups can S
-&-OH
I
+ CSs + Ba(OH)l-+ -A- O-G-S-Ba/2 ”
Fr I
react. Copper and silver xanthates have been prepared,la7 which are convertible to methyl xanthates with methyl iodide. Xanthation proceeds to a small extent beyond the mono stage with methyl a-D-glUC0-
H 0-
OCHz LXIX
pyranoside. 12* When phenyl p-D-glucopyranoside reacts with an excess of carbon disulfide in a quaternary base, a tetraxanthate is obtained. Information concerning the structure of the monoxanthate of methyl a-D-glucopyranoside was obtained by forming its methyl xanthate (LXX) by reaction of methyl iodide with its silver salt. 129 Controlled benzoylation of this methyl xanthate yielded a monobenzoyl monoxanthate (LXXI). Acid hydrolysis of the xanthate linkage of LXXI, followed again by selective benzoylation yielded methyl 2,6-di-O-benzoyl-a-~glucopyranoside (LXXII). Since xanthation of secondary hydroxyl (125) For a review of t h i process see E. Kline in “Cellulose and Cellulose Derivatives,” E. Ott, editor, Interscience Publishers, Inc., New York, 1943, p. 808. (126) T. Lieser and W. Nagel, Ann., 496, 235 (1932). (127) T. Lieser and A. Hackl, Ann., 611, 121 (1934). (128) T. Lieser and R. Thiel, Ann., 622,48 (1936). (129) T. Lieser and E. Leckayck, Ann., 619, 279 (1935).
32
JAMES M. BUGIHARA
groups has been demonstrated to be possible, and since benzoylation of primary hydroxyl groups is preferred, the xanthate grouping was assumed to occupy position 2 and not position 6.
C!XInOBa ? LXXI
I
CHgOBz LXXII
The xanthation of cellulose yields products of varying degrees of substitution, depending upon the conditions used. When cellulose is dispersed in tetraethyl-ammonium hydroxide so that all hydroxyl groups are available for reaction, a cellulose trixanthate salt of the base is obtained. 130 When cellulose is xanthated with carbon disulfide and sodium hydroxide, a product containing about one xanthate group per two anhydro-D-glucose units may be obtained. When such a product reacts with diazomethane, which attacks free hydroxyl groups to only a negligible extent, and the resulting methylated cellulose is hydrolyzed, D-glucose and 2-O-methyl-~-glucose are obtained;72.128*132 the inference that the hydroxyl group at carbon atom 2 has selective reactivity is justified, and indeed there appears to be evidence that leads to an impor' ~ ~ that tant specification concerning this carbon atom 2. L a ~ e r found heterogeneous xanthation t o the extent of approximately 0.5 xanthate per anhydro-D-glucose unit, leads t o substitution in the 2-position on half of the D-glucose units. Further heterogeneous xanthation results in substitution in the 3-position of the once substituted units, indicating that the amorphous regions only are attacked. These results are in agreement with x-ray investigations.134 (130) T. Lieser and E. Leckzyck, Ann., 622, 56 (1936); T. Lieser, Kolloid-Z., 81, 234 (1937). (131) T. Lieser, Chem.-Zlg., 80, 387 (1936); Chem. Abstracts, 30, 8604 (1936). (132) T. Lieser, Papier-Fabr., 36, Tech.-wiss. Tl., 272 (1938); Chem. AbsCacts, 34, 6857 (1938). (133) K. Lauer, Makromol. Chem., 6, 287 (1951). (134) K. Hess and C. TroguB, Cellulosechemia, 18, 84 (1932); W. Schramek, Papier-Fabr., 36, Tech.-wiss. TI.,226 (1938); Chem. Abstracts, 32, 6855 (1938); G. Centola, Atti X" wngr. intern. chim., 4, 117, 129, 138, 722, 728 (1938); Chem. Abstracts, 34, 2169, 2169, 5277, 5279, 6279 (1940).
RELATIVE REACTIVITIES OF HYDROXYL ffROUP8
33
3. Other Esters Polyhydric alcohols are nearly quantitatively acetylated by the common procedures. Both primary and secondary hydroxyl groups are nearly completely esterified but there is a distinct difference in the equilibrium constants concerned. However, acetylation has not been successfully applied for the selective esterification of primary hydroxyl groups in the presence of secondary ones. On the other hand, selective deacetylation has been realized in some instances. The product that was formed136by the treatment of a- or P-D-glucose pentaacetate with piperidine was isolated in crystalline condition by Hodge and Ristlas and shown to be N (3,4,6-tri-O-acetyl-~-glucopyranosyl)-piperidine (LXXIV). Since 2,3,4,6-tetra-0-acetyl-~-glucopyranose (LXXIII),but not N(2,3,4,6tetra-O-acetyl-D-glucopyranosyl)-piperidine(LXXV), yields LXXIV, the
Ho+7 HCOAc
F
H OAc
HCO
HkO-
I
1
CHpOAc LXXIII
CHZOAC LXXIV
HCOAc HCO
I
CHZOAO LXXV
removal of acetyl from carbon atom 2 is required for the reaction. 2-Substituted D-glucose derivatives are preparable from LXXIV. Bourne, Stacey, Tatlow, and Tat10w”~found that methyl 4,6-0-benzylidene-2,3bis(0-trifluoroacety1)-a-D-glucopyranoside (LXXVI) can be methanolyzed to form methyl 4,6-0-benzylidene-0-trifluoroacetyl-a-~-gluc0(135) (136) (137) Soc., 820
H. Vogel, Ber., 70, 1193 (1937). J. E. Hodge and C. E. Rist, J . Am. Chem. Soc., 74, 1498 (1952). E J. Bourne, M. Stacey, (Mrs.) C.E.M. Tatlow and J. C.Tatlow, J . Cliem, (1951).
34
JAMES M. SUGIHARA
pyranoside (LXXVII). The mono(0-trifluoroacetyl) compound is converted into the following derivatives of methyl 4,6-0-bensylidene-t~glucopyranoside: the 2-0-tosyl-3-0-trifluoroacetyl derivative (LXXX) with tosyl chloride in pyridine, the 3-0-acetyl-2-0-trifluoroactyl derivative (LXXVIII) with acetic anhydride in pyridine, and the 2-0-acetyl-30-trifluoroacetyl derivative (LXXIX) with acetic acid and trifluoroacetic acid. Since an orthoester structure for LXXVII appears unlikely because of the trans arrangement of substituents about carbon atoms 2 and 3, a migration of trifluoroacetyl is believed to be responsible. Since migration is favored by alkaline conditions, the trifluoroacetyl group is believed to occupy position 3 in LXXVII. If these assumptions are correct, the trifluoroacetyl group on position 2 is more susceptible
LXXVIII
LXXIX
LXXX
Acetone-soluble cellulose acetate is prepared by deacetylating cellulose triacetate. The product formed directly is unsatisfactory. Thus the distribution of free hydroxyls and acetate groupings is of primary importance. Cramer and Purves118@)studied the distribution by tosylation and found that the acetyl removal from primary and secondary hydroxyl groups occurs at approximately the same rate, but th&t the number of
RELATIVE REACTIVITIES OF HYDROXYL GROUPS
35
free hydroxyls in position 3 is approximately one and one-half times as great as in position 2.118(.) This is in agreement with tritylation experiments which indicate that approximately one-third of the free hydroxyl groups are primary.94~138 The number of free glycol groupings in positions 2 and 3 in the acetone-soluble cellulose acetate is found to be much lower than would be predicted on a random distribution basis.Ia9 This suggests the possibility of decreased tendency of hydrolysis of acetate groups in positions 2 or 3 when the adjoining position bears a free hydroxyl group. Selective benzoylation of the hydroxyl groups of carbohydrates has been observed frequently. Thus, Levene and Raymond13gaobtained from the corresponding methyl 2,3,6-tri-0-benzoyl-~-~-glucopyranoside 2,3-dibenzoate. 1,6-Di-O-benzoyl-~-glucitolwas prepared by direct benz~ylation;'~ proof ~ that the ester linkages are primary ones was demonstrated by lead tetraacetate oxidation. 141 A di-0-benzoyl-D~ shown to mannitol that was prepared by Einhorii and H ~ l l a n d t ' *was be the 1,6-di-O-benzoyl derivative. 143 3,4-Di-O-tosyl-~-mannitol,~~~ as well as D-mannitol in the presence of boric acid,47is esterified at the primary hydroxyl groups only, to yield the 1,6-di-O-benzoyl derivative. 1,2,3-Tri-O-benzoyl-~-glucoseand benzoyl chloride in pyridine give 1,2,3,6-tetra-0-benzoyl-~-g~ucose, leaving the 4-position free. 146 Further examples of preferential benzoylation of primary hydroxyl groups are the following: 6-O-benzoyl-~-glucose diethyl thioacetal (LXXXI) from 6-0the thioacetal in the presence of boric acid4?and without boric ben~oyl-D-glucose dibenzyl thioacetal, 5-O-benzoyl-~-arabinose diethyl thioacetal, and 6-O-benzoyl-2-0-methyl-~-glucosediethyl thioacetal from the corresponding t h i o a ~ e t a l s ,and ~ ~ ~ phenyl 6-O-benzoyl-/3-~-glucopyra~iosidel~~ and o-cresyl 6-O-benzoyl-p-~-glucopyranoside (LXXXII) from the corresponding glucopyranosides. When reaction is carried (138) P. P. Shorygin, A. E. Veitsman and N. N. Markarova-Zemlyanskaya, J . Gen. Chem. (U.S.S.R.), 7 , 430 (1937). (139) F.B.Crrtmer, R. C. Hockett and C. B. Purves, J . Am. Chem. Soe., 61,3463 (1 939). (139a) P. A. Levene and A. L. Raymond, J . Biol. Chem., 97, 763 (1932). (140) A. MWer, Ber., 66, 1055 (1932);67, 830 (1934);K. Heyns and W. Stein, Ann., 668, 194 (1947). (141) R. C. Hockett and H. G. Fletcher, Jr., J . Am. Chem. Soc., 66, 469 (1944). (142) A. Einhorn and F.Hollandt, Ann., 301,95 (1898). (143) P. Brigl and H. Griiner, Ber., 66,641 (1932). (144) P. Brigl and H. Griiner, Ber., 67, 1969 (1934). (145) P.Brigl and H. Gruner, Ber., 66, 1428 (1932). (146) T. Lieser and R. Schweizer, Ann., 619, 271 (1935);Naturwissenschujten, 23, 131 (1935). (147) N.K.Richtmyer and Eleanor H. Yeakel, J. A m .Chem. SOC.,66,2495 (1934).
36
JAMES M. SUGIHARA
beyond the stage of esterification of primary hydroxyl groups, selective reactivity is still indicated in some cases. Methyl a- and /3-n-glucopyranosides yield the 2,6di-O-benaoyl derivatives, 146 n-xylose dibenzyl thioacetal yields a di-0-benzoyl derivative, 148 and n-glucose in the presence of boric acid yields the 2,6-diben~oate.~’On the other hand, HC(SCdh) z HboH HObH
a - O - C H I \CH,HAOH
HobH
Brigl and M u h l ~ c h l e g e were l ~ ~ ~able to isolate 3,4,5,6-tetra-O-benzoyl-nglucose diethyl thioacetal from the thioacetal and benzoyl chloride in an aqueous solution of alkali. When the reaction is carried out in pyridine, both the tetra- and the penta-benzoate are obtained. The tetrabenzoate has been described as a convenient intermediate for the synthesis of 2-0-methyl-D-glucose and its derivatives. 149 It is somewhat surprising that position 2 should exhibit this resistance to benzoylation, since preferential methylation occurs in this position. A benzoyl migration could possibly explain the anomalous observations. Selective debenqoylation has been shown to occur by Restelli de Labriola and DeulofeulKOin the cleavage of penta-0-benzoylhexonic acid nitriles (LXXXIII) to form 0-benzoyl-pentose dibenzamides (LXXXIV) with ammonia. Since tetra-0-benzoyl-L-rhamnonic acid iiitrile (LXXXV) yields 5-deoxy-~-arabinose dibenzamide (LXXXVI), the benzoyl group in the Wohl degradation products is assumed to be in the 5 positions of the resulting pentoses. Formic acid appears to show some selectivity in preferentially describes the preparaesterifying primary hydroxyl groups. Traquair lK1 tion of unstable starch formates. The monoformate is believed to be esterified at position 6. The periodate oxidation of monoformates of starch and limit dextrin indicates that ester linkage is predominantly (148) (149) (150) (151)
P. Brigl and H. Mtihlschlegel, Ber., 63, 1551 (1930). P. Brigl and R. Schinle, Ber., 63, 2884 (1930). E. Restelli de Labriola and V. Deulofeu, J . Org. Chem., 12, 726 (1947). J. Traquair, J . SOC.Chem. Ind., 28, 288 (1909).
RELATIVE REACTIVITIES OF HYDROXYL GROUPS
37
at position 6.lS2 Moe, Miller and Buckleys4have repeated this investigation and have demonstrated the necessity of pH control during the CN
HC(NHBz)z
AHOBa
AHOH
AHOBz
NH,
+
AHOH
&HOBa
&HOH
bHOBz
hHaOBa
AHIOBs LXXXIII CN
HC(NHB2)z
H&OBa HhOB2
LXXXIV HhoH
NHf HOAH
BzdH
c:
HObH
Be0 H AH* LXXXV
AH3
LXXXVI
periodate oxidation, since hydrolysis of the formate ester linkage may occur. Selective denitration is illustrated in the reaction of pyridine and D-mannitol hexanitrate (LXXXVII). The product of this reaction was
02NobH 02Noc TONo2
ZH20N02
CsHsN OzNO O Z N 0H C
H ON02
HhOH
HAON02
H ON02
CHpONOa I LXXXVII
A€IsONOt LXXXVIII
&
identified by Hayward163 as being D-mannitol 1,2,3,5,6-pentanitrate (LXXXVIII). This cleavage of a secondary nitrate ester grouping is in agreement with the observations of Gladding and P u r v e ~ who , ~ ~found ~ (152) D.Gottlieb, C. G. Caldwell and R. M. Hixon, J . Am. Chem. Soc., 62, 3342 (1940). (153) L. D. Hayward, J . Am. Chem. Soc., 73, 1974 (1951), (154) E.K.Cladding and C. B. Purves, J . Am. Chem. Soc., 66, 76 (1944).
38
JAMES M. SUGIHARA
that methyl 3,4,6-tri-O-acetyl-~-~-glucopyranoside 2-nitrate denitrates in alkali more readily than methyl 2,3,4-tri-O-acetyl-/3-~-glucopyranoside 6-nitrate. They call attention to the close analogy of the cleavage of nitrate ester groups t o the cleavage of tosyl ester linkages. A classical selective reaction, described by Fischer and Armstrong, Is5 in which 6-bromo-6-deoxy-2,3,4-tr~-0-acetyl-a-~-g~ucopyranosy~ bromide (LXXXIX) is obtained from /3-D-glucose pentaacetate and liquid hydrogen bromide, has had application in the synthesis of 6-substituted D-glucose derivatives. The action of liquid hydrogen chloride on D-glucose has been studied by Hess, Stricker and Rutkowski,166who have postulated a 1,1-chlorohydrin (XC) as an initial intermediate of the reaction.
c1 HbOAc AcOiH
I
H ~ O A CI
HbCl H&OH 1 HO~H HAOH
HbOH
AHzOH LXXXIX
xc
The resistance to hydrolysis of phosphate esters of primary alcohols167 was used to advantage by Seegmiller and Horecber,ls8 who allowed D-glucose to react with polyphosphoric acid and subjected the resulting mixed phosphate to acid hydrolysis to obtain D-glucose 6-phosphate. D-Glucopyranose polymers that are uniformly substituted selectively in position 2 are claimed.16g These products are obtained by treating starch with amides and amines in a non-aqueous medium. WinterlB0 prepared condensation products of urea and mono- and poly-saccharides from aqueous solutions.
V. SELECTIVE OXIDATION Among the very selective oxidants are the glycol-cleaving reagents, periodic acid and lead tetraacetate. These have been briefly mentioned (155) E. Fischer and E. F. Armstrong, Ber., 36, 833 (1902). (156) K. Hess, F. Stricker and R. Rutkowski, Cellulosechemie, 21, 125 (1943). (157) Kathleen R. Farrer, J. Chem. Soc., 3131 (1949). (158) J. E. Seegmiller and B. L. Horecker, J. Bid. Chem., 192, 175 (1951). (159) K. M. Gaver, Esther P. Lasure and L. M. Thomas, U. S. Pat. 2,538,903 (Jan. 23, 1951). (160) H. Winter, Brauwissenschuft, 113 (1951) ; Chem. Abstracts, 46, 3009 (1952).
RELATIVE REACTIVITIES OF HYDROXYL GROUPS
39
in the section on glycol complexes. Red lead161and lead dioxide162have been proposed as glycol-spli tting oxidants; they are believed to function in the same manner as lead tetraacetate. Sodium bismuthate has also been established as a glycol-splitting reagent. 162a Enzymic oxidation1s3has been of great value in the synthesis of rare ketoses. The selective action that is involved may be described in terms of the structural features that have been found to be necessary. When Acetobacter xylinum is used as the oxidizing organism, polyhydric alcohols (XCI or XCII) with two secondary hydroxyl groups which are configurationally cis with respect t o each other and adjacent to a primary hydroxyl group are required, to permit the oxidation of the secondary hydroxyl, adjacent to the primary group, to a keto group. This generalization is known as " Bertrand's Rule." 16* A cetobacter suboxydans
(A
HA-OH
€I -OH
AHZOH
€I -OH
A . rylinum ____ + o r A . svboxydnnn
A=O
1
CHZOH
XCI
""bH A HO-
H hH*OH
A . zylinum
A
"O-(L9,
I
CHzOH
XCII
has been found to be more desirable since higher yields of ketoses are generally obtained. Hann, Tilden and Hudsonls5 have determined that the structural requirements of A . suboxydans are similar to those for A . xylinum except that there is greater specificity since only the D-forms (XCI) of polyhydric alcohols are oxidized. Extensive studies by Hudson and coworkers166have confirmed the generalization made earlier. (161) L. Vargha, Nature, 162, 927 (1948); L. Vargha and M. Remhyi, J . Chem. SOC.,1068 (1951).
(162) Y . Matsushima, J . Chem. SOC.Japan, 69, 159 (1948). (162a) W. Rigby, Nature, 164, 185 (1949); J . Chem. SOC.,1907 (1950). (163) R. Lohmar and R. M. Goepp, Jr., Advances in Carbohydrate Chem., 4, 226 (1949). (164) G . Bertrand, Compl. rend., 126, 762 (1898); Ann. chim. phys., [S], 3, 181 (1904). (165) R. M. Ham, Evelyn B. Tilden and C. S. Hudson, J . Am. Chem. Soc., 60, 1201 (1938). (166) J. W. Pratt, N. K. Richtmyer and C. S. IIudson, J . Am, Chem. Soc., 74, 2210 (1952); and preceding articles.
40
JAMES M. SUGIHARA
A recent important extension of the Hann, Tilden and Hudson rule has its origin in their observation that a reducing substance is produced by the action of Acetobacter suboxydans on L-fucitol; this result was confirmed by Bollenback and Underkofler.ls7 Inspection of the stereoformula of L-fucitol (XCIII) shows a trans position for the hydroxyl CHzOH (1) HobH
(2)
IHZoH
HO H
HboH
(3)
HbOH
HboH
(4)
A=O
H d H (!!HI XCIII L-Fucitol
(5)
(6)
HObH &Ha XCIV
groups at carbon atoms 2 and 3 and also for those at carbon atoms 4 and 5 , and the rule specifies that Acetobacter suboxydans would not be expected to attack such arrangements. Some years later, when the identity of the reducing substance was established by Richtmyer, Stewart and Hudson,188it proved to be a ketose sugar of a new type; they named it ~-fuco-4-ketose. The oxidation of the hydroxyl group of carbon atom 4 of L-fucitol indicates that the configuration XCV is equivalent qualitatively to XCVI (the asterisks mark the hydroxyl groups that are oxidized) with respect to the action of the organism, and that the oxidation of HAOH
(3)
b
H OH
HAOH* (4) d O H * HoAH
(5)
bH20H
AH8
xcv
XCVI
L-fucitol by it conforms with this extended interpretation of the Hann, Tilden and Hudson rule. Further studies of the action, or lack of action, of Acetobacter suboxydans on other w-deoxy-alditols are being reportedlB9 and so far they indicate the general applicability of the rule under the extended interpretation that a terminaE methyl group is to be regarded as qualitatively equivalent to a hydrogen atom, insofar as the specificity of the oxidation by Acetobacler suboxydans is concerned. (167) G.N. Bollenback and L. A. Underkofler, J . Am. Chem. SOC.,72,741 (1950). (168) N. K.Richtmyer, Laura C. Stewart and C. S. Hudson, J . Am. Chem. SOC., 72, 4934 (1950).
(169) N. K.Richtmyer, private communication.
RELATIVE REACTIVITIES OF HYDROXYL GROUP8
41
The stereospecificity of the oxidation of cyclitols and deoxycyclitols by Acetobacter suboxydans has been defined by Magasanik, Franzl and
A
H -OH
HL-oH
H L H
HLOH
H L O H or NO-LH AH$
AH*
t:
H -OH A=O A . eubozgdanr
---+
i-
Ht:--OH
H L o R or H+ AH*
H
AH8
Chargaff.l?O Only a polar hydroxyl group is oxidized which has an equatorial hydroxyl group in the meta position (counterclockwise if north polar and clockwise if south polar) to the polar hydroxyl (see Fig. 1).
Fro. l.-epi-Inositol (Carbon to Oxygen Bonds Shown; Carbon to Hydrogen Bonds Not Shown). North Polar Hydroxyk a t G I and C-3. Equatorial Hydroxyle at (2-2, C-4, C-5, and C-6. North Polar Hydroxyl a t C-1 Oxidized; North Polar Hydroxyl at C-3 Not Oxidized.
The chemical oxidation of hydroxyl groups of carbohydrates in which there is no cleavage of carbon to carbon bonds may involve a primary or a secondary alcohol function. Many of the oxidants are relatively non-specific in action. Some are specific only when the reaction conditions are carefully controlled. Nitric acid has found some application in the oxidation of primary alcohol functions to carboxyl groups. However, yields are generally low and specificity poor. Nitrogen dioxide is much more selective in its action, and in the absence of labile aldehydic groups, primary hydroxyl groups are quite smoothly oxidized to the corresponding carboxylic acid. Maurer and Drefahl”’ obtained methyl uronic acids (XCVII) from methyl glycosides, and Maurer and Reiff172 prepared an incompletely oxidized celluronic acid. In the hands of (170) B. Magaeanik, R. E. Franzl and E. Chargaff, J . Am. Chem. Soc., 74, 2618 (1952). (171) K. Maurer and G. Drefahl, Ber., 76, 1489 (1942).
(172) K. Maurer and G. Reiff, J . makromol. Chem., 1, 27 (1943).
42
JAM=
M. STJQIHARA
Kenyon and coworkers17amuch information concerning the preparation and properties of the product of oxidation of cellulose with nitrogen dioxide has been elaborated. This oxidation has been shown to occur with the initial rapid incorporation of nitrogen by the cellulose followed by a slower 10ss.l~~ This is interpreted as an initial nitration followed
7
bHOH AHO-
Ao,a
AH2OH
XCVII
by an oxidative denitration. Use of anhydrous nitric acid and nitrogen dioxide allows the formation of a cellulose mononitrate, which is interpreted to be the 6-nitrate (XCVIII) since in the subsequent slower denitration reaction, which appears to be catalyzed by nitric acid, celluronic acid (XCIX) is obtained. This mechanism has been suggested as being illustrative of nitric acid oxidations of any organic compound - -0-CH
n HNOI __f
kH20H
n
XCVIII
containing one or more hydroxyl groups. K e r F has applied this method of oxidation to starch and found that more uronic acid carboxyl is obtained from amylose than from amylopectin, and therefore this evidence is construed as qualitative support for branching at carbon 6 in amylopectin. (173) E.C . Yackel and W. 0. Kenyon, J . Am. C k m . Soc., 64, 121 (1942); C. C. Unruh and W. 0.Kenyon, ibid., 64, 127 (1942); E. C. Yackel and W. 0. Kenyon, U.S. Pat. 2,232,990 (Feb. 25, 1941). (174) P. A. McGee, W. F. Fowler, Jr., E. W. Taylor, C. C. Unruh and W. 0. Kenyon, J . Am. Chem. Isoc., 69, 355 (1947). (175) R. W. Kerr, J . Am. Chem. Soc., 74, 816 (1950).
RELATIVE REACTIVITIES O F HYDROXYL GROUPS
43
Oxidation of hydroxyl groups with oxygen with no cleavage of carbon to carbon bonds is in general rather non-specific. Only in a few instances has there been demonstrated the selective oxidation in good yield, of a primary hydroxyl group in the presence of secondary hydroxyl groups. D-Glucuronic acid (CI) has been obtained in a yield of 50-600/, by the oxidation of 1,2-O-isopropylidene-~-glucofuranose(C) with oxygen over a platinum-carbon catalyst. 176 D-gluco-Saccharic acid has been obtained
__f
HbOH
H 0-
CI
in a yield of 54% by the oxidation of D-glucose with air or oxygen over platinum. l77 Catalytic oxidation with platinum permits the preparation of 2-keto-~-gulonic acid (CIII)17* from L-sorbose (CII) and 2,3-O-isopropylidene-2,5-anhydro-~-gulo-saccharicacid (CV)179 from 2,3-isopropylidene-L-sorbose (CIV), although yields are low in both instances. CHtOH
COiH
A=O
b=O
c:
HO H
HAoH
b
1:
HO H
-+
HO H AH2OH CII
T-co2 IP LOCH
HbOH
HAOH
AI
HO H CHnOH CIII
-0bH AOzH
cv
The oxidation of sugars and polyols by halogenslso has been extensively studied. Polyols may be oxidized to aldoses and ketoses albeit in (176) C. L. Mehltretter, B. H. Alexander, R. L. Mellies and C. E. Rist, J . Am. Chem. Soc., 73, 2424 (1961); aee p. 231. (177) C. L. Mehltretter, C. E. Rist and B. H. Alexander, U. S. Pat. 2,472,1(38 (June 7, 1949). (178) K. Heyna, Ann., 668, 171 (1947); 0. Dalmer and K. Heyns, Canadian Pat. 381,575 (May 23, 1939). (179) N. R. Trenner, U. S. Pat. 2,428,438 (Oct. 7, 1947). (180) J. W. Green, Advances in Carbohydrate Chem., 3, 129 (1948).
44
JAMES M. SUGIHARA
most instances in poor yields. The oxidation of D-glucose with aqueous hypobromite yields D-gluconic acid.Is0 Further oxidation is believed to lead to the formation of 2-keto-D-gluconic acid and 5-keto-~-gluconic acid with the former decarboxylating rapidly to yield D-arabonic acid. lS1 SmithlS2describes methods of synthesis of 2-keto acids.
VI. CONCLUSIONS The apparent selective reactivity of hydroxyl groups of carbohydrates in many instances seems to be a consequence of spatial arrangement of these groups. This is especially indicated in those reactions, such as acyl migration, where the postulation of a cyclic intermediate seems to explain the course of the reaction. Neighboring groups in general may have a very pronounced effect on the reactivity of a given hydroxyl group. The enhanced reactivity of the 2-hydroxyl as compared to other secondary hydroxyl groups has been noted primarily in reactions requiring alkaline media. This effect is probably a result of the greater acidity of hydroxyl groups adjacent t o a carbonyl or a potential carbonyl group. In many instances the reactivity of the primary alcohol group is greater than that of a secondary alcohol group. Certain oxidation reactions, tritylation, tosylation, and some acid catalyzed esterification reactions are those which exhibit this selectivity. The greater steric availability of this necessarily terminal function may be a factor. The greater reactivity of the primary and the 2-hydroxyl group over those of the other secondary alcohol groups is strongly indicated. However, differences between the reactivities of the primary and the 2-hydroxyl group frequently appear to be small and therefore dependent upon reaction conditions and structural variations. (181) C. L. Mehltretter, W. Dvonch and C. E. Rist, J . Am. Chem. SOC.,73, 2294 (1950); M. Honig and F. Tempus, Ber., 67, 787 (1924). (182) F. Smith, Advances in Carbohydrate Chem., 2, 84 (1946).
THE CHEMISTRY OF THE 2-DESOXYSUGARS BY W. G. OVEREND
AND
The Pennsylvania State College, t 7 .S . A . and Chemistry Department, University of Birmingham, England
M. STACEY Chemistry Department, University of Birmingham, England
CONTENTS I. 11. 111. IV.
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..... .........,....,. Nomenclature.. . . . ............................................. Occurrence and Isolation . . . . . . . . . . . . . . . . . . . . . . . . . . . Detection. . . ................................................... ....
.
2. Diphenylamine Reaction. . . . , . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . 3 . Tryptophan Reaction. . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4. Feulgen Reavtion.. . . . . . . . . . . . ...... . . .... ... . .. . . . . ... 5. Other Methods , . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . .,, .. . ... .... . ... V. Synthesis of 2-Desosyxugars . . . . . . . . . . . . . , . . . 1. Biosyxithesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .... 2. Glycal M e t h o d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 . Fiucher and Sowden Method ................................... 4. From 2,a-Anhydro Sugars.. . . . . . . . . . .,.. . . . . . . . . , _ . . . 5. Ot)her Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6. Synthesis of 2,:3-L)idesoxysugars. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 . Synthesis of 2-Desoxyhexomethyloses IYhich Orcur in Cardiac Glycositles VI. Transformation Products . . . . . . . . . . . . . . . . . . . . . . . . . . . ......... _..... 2. 3. 4. 5.
45 46 49 53 53 53 58 61 64
66 66 68 73 75 83 88 89 91 91 ............................. . . ... ............ N-Glycosides . . . . . . . . . . . . . . . . . . . . . . . . . . . ’ . . . . . . . . . . . . . . . . . . . . . 96 Oxidation Reactions and Products. . . . . . . . . . . _ . . . . . . . . . . . . . . . . 99 101 Reduction Products. . . . . . . . . . . , , . . . . . . .. . Phosphate Esters. . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
I. INTRODUCTION The 2-desoxypentoses form the carbohydrate component of the desoxynucleic acids and are therefore of particular biological importance. I n recent years the chemistry of 2-desoxysugars generally, has been considerably broadened. I n particular, new methods of synthesis have been developed for the preparation of many of the didesoxysugars known as the (‘2-desoxyhexomethyloses ” which occur naturally as components of the cardiac glycosides. The formation, structure, arid stability of various 0- and N-glycosides of sugars of this class have been examined in 45
46
W. G . OVEREND AND M. STACEY
detail, as also have the properties of many other derivatives and transformation products. No comprehensive account of these advances has appeared so far in the literature and it is hoped that this review will bring into perspective the numerous publications on the chemistry of 2-desoxysugars and will stimulate further investigations. Specialized aspects of the chemistry of 2-desoxyhexoses have been described in detail already. An excellent review of the chemistry of the carbohydrate components of the cardiac glycosides appeared in 1945 in Volume I of this series,1s2and consequently only developments in this subject since that date will be included in the present account. The composition and function of desoxyribonucleic acids have been studied extensively in recent years, and wider knowledge of the behavior of 2-desoxy-~-ribosebecame urgent. In this review developments in nucleic acid chemistry which have led t o advances in our knowledge of 2-desoxypentoses (and vice versa) will be stressed. 11. NOMENCLATURE The nomenclature used for the class of compounds known as “desoxysugars” is extremely confusing. The term “deoxy ” as in present English usage is likely to replace “desoxy.” It has been a common practice t o adopt the source of preparation rather than the actual structure of the sugar as the basis of nomenclature. When such a system of nomenclature is applied to substances having fewer asymmetric centers than the parent compounds from which they are named, it may be found that more than one name can be directly applied to a single chemical compound. For example, the first 2-desoxyhexose synthesized, was prepared from D-glucose and so was named 2-desoxy-~-glucose,~ but this sugar could also be prepared from D-mannose by the same series of reactions, so 2-desoxy-~-mannose is a n alternative name. Recently4 this same 2-desoxyhexose has been prepared from D-arabinose without using either D-glucose or D-mannose as intermediates, so that at first sight this system of nomenclature would appear to be outmoded. Sometimes less obvious names were used since the source of preparation itself was given a trivial or unsystematic name. %Desoxy-~-xylose was obtained by Kiliani and Loeffler5by the degradation of metasaccharin and consequently they named it “metasaccharopentose.” Gakhokidze6. (1) R. C. Elderfield, Advances i n Carbohydrate Chent., 1, 147 (1945). (2) See also T. Reichstein, Angew. Chem., 63, 412 (1951). (3) E. Fischer, M. Bergmann and H. Schotte, Ber., 63, 509 (1920). (4) H. 0. L. Fischer and J. C. Sowden, J. Am. Chem. SOC.,69, 1048 (1947). (5) H. Kiliani and P. Loeffler, Ber., 38, 2667 (1905). (5a) A. M. Gakhokidze, Zhur. ObshcheZ Khim., 16, 1907 (1946).
CHEMISTRY O F THE
2-DESOXYSUGARS
47
(for other references, see page 69) in his work on the synthesis of 2-desoxypentonic and 2-desoxyhexonic acids has used a somewhat similar type of nomenclature. Bergmann and his coworkersa did not regard desoxysugars as true sugars and introduced a system of nomenclature whereby the ending ‘‘desose” was used t o denote a desoxysugar. Thus 2-desoxyglucose was referred t o as glucodesose. The system never attained universal acceptance, and in the early development of desoxysugar chemistry mainly led to an undesirable duplication of names. Other confusions arise from the fact that frequently desoxysugars were named from the materials in which they occurred naturally. 2-DesoxyD-ribose, the sugar component of thymonucleic acid, was often designated as thyminose. Likewise the 2-desoxyhexose derivatives found in the cardiac glycosides were named from the source, as for example, cymarose, digitoxose, diginose, etc. Derivatives and transformation products were named on the basis of this terminology and names such as cymaronic acid and diginonic acid are encountered in the literature. Although these trivial names are nowadays not used so frequently by chemists, they are still found in contemporary publications relating to the biological sciences. Proposals have been made to systematize the nomenclature of desoxysugars. Sowden7 suggested a type of nomenclature similar to th a t advanced by Wolfrom, Thompson and EvansRto replace the trivial and non-systematic names for the ketose sugars. It was proposed to denote by a prefix the stereochemical configuration of the hydroxyl groups in desoxypentoses and desoxyhexoses. Thus I (2-desoxy-~-ghcose)on this system of nomenclature is named ~-arabo-2-desoxyhexose. The dotted outline denotes the portion of the sugar to which the prefix relates. Likewise, I1 (2-desoxy-~-ribose) is termed ~-erythro-2-desoxypentose. CHO
CHO
I
CHn
HAOH
I
HCOH
I1 (6) M. Bergmann, H. Schotte and W. Lechinsky, Ber., 66, 158 (1922). (7) J. C. Sowden, J . A m . Ch,em. SOC.,69, 1047 (1947). (8) M. L. Wolfrom, A. Thompson and E. F. Evans, J. A m . Chem. SOC.,67, 1793 (1945).
48
W. 0. OVEREND AND M. STACEY
This system is admirable for naming 2-desoxysugars but is not considered 90 good for didesoxysugars, especially when the desoxy sites are not adjacent, as for example in 2,4-didesoxysugar derivatives. In future publications of original researches it might be advantageous to adopt a scheme of this type. Fieserg suggested an alternative scheme for sugar nomenclature. Each asymmetric center in the sugar molecule is denoted by a- or p- depending upon whether the attached hydroxyl (or substituted hydroxyl) group is disposed to the right or to the left, respectively, in the Fischer projection formula as conventionally written. Positions of desoxy-groups, where there is no asymmetry, would be denoted by the absence of either symbol at these positions in the carbon chain of the sugar molecule. Neither of these systems has beer) generally adopted and it is not proposed to use them in this review. Instead, the older procedure of naming a desoxysugar from its parent hexose or pentose, will be used, with the added proviso that of the two names generally applicable, the one adopted will be that derived from the parent sugar in the D-series which has the hydroxyl group a t carbon atom 2 directed to the right in the Fischer projection formula. (We are indebted t o Dr. E . J. Bourne for helpful suggestions regarding this system of nomenclature.) For example, I will be considered as derived from D-glucose (111) rather than from D-mannose (IV) and so will be named 2-desoxy-~glucose. Similarly V will be referred t o as 2-desoxy-~-alloserather than 2-desoxy-~-altrose,since the hydroxyl group at carbon atom 2 in the parent sugars is directed t o the right in the projection formula of D-allose (VI) whereas it is to the left in D-altrose (VII). CHO HboH
H oAH
CHO HOAA
HObH
CHO
CHO
8"'
H OH
I
H OH
A
c:I
HIoH
IHO
KO H
HAOH
HbOH
HAOH
H OH
H OH
HAOH
HAOH
H OH
HLOH
HLOH
HAOH
bHzOH 111
h20H
IV
h Z 0 H
v
CHzOH I
VI
bHzOH VII
Although this system of naming desoxysugars may be less rigid than that devised by Sowden' i t has the advantage of maintaining continuity and familiarity with the nomenclature used in the majority of previous publications. To avoid confusion it is considered important in a review summarizing the chemistry of 2-desoxysugars, that changes in nomenclature from that adopted by most previous authors, should be minimized. (9) L. Fieser, J . Am. Chem. Soc., 72, 623 (1950).
CHEMISTRY O F THE
2-DESOXYSUGARS
49
The whole question of carbohydrate nomenclature is now under review by a joint Anglo-American Committee.*
111. OCCURRENCE AND ISOLATION 2-Desoxy-~-riboseoccurs naturally as the carbohydrate component of desoxyribonucleic acids. From an examination by the ultraviolet chromatographic technique, of a range of nucleic acids isolated from animal, plant and bacterial sources, Chargaff and his coworkers1° have concluded that this sugar is the only 2-desoxypentose found so far to occur naturally in the nucleic acids. 2-Desoxy-~-riboseexists in nucleic acids, linked glycosidically to either a purine or pyrimidine base. The purine bases found are adenine and guanine and originally the only pyrimidine bases were considered t o be thymine and cytosine. Recent investigations have revealed th a t 5-methylcytosine is also present. i n some nucleic acids in small quantity,"-13 and is linked glycosidically t,o 2-desoxy-~-ribose.l~ Of the nucleic acids so far examined, wheat-germ desoxypentose nucleic acid appears to contain the largest amount of 5-methylcytosine-3 (2'-desoxyD-riboside) and the nucleoside has been isolated from this source." Despit'e a claim to the contrary, it is doubtful whether 5-methylcytosine3 (2'-desoxy-~-riboside) occurs in bacterial nucleic acids. Using as a basis for identification the optical properties of the crystalline picrate, Johnson and Coghill17 claimed over a quarter of a century ago to have discovered 5-methylcytosine among the hydrolysis products of tuberculinic acid (a degraded sample of desoxypentose nucleic acid from M . tuberculosis). This claim must be accepted with great reserve since Chargaff and his colleagues, l 8 using the chromatographic method, could find no trace of 5-methylcyt,osine in avian tubercle desoxypentose nucleic acid. Moreover, Wyatt and Smith19 could find no 5-methylcytosine desoxyriboside in certain viral and bacterial nucleic acids, including a
* Since this review was completed, agreed rules of carbohydrate nomenclature have been published (see Editorial Report on Nomenclature, Appendix 2, J . Chem. Soc., 5108 (1952)). (10) 15. Chargaff, E. Vischer, R. Doniger, Charlotte Green and F. Misani, J . Biol. Chem., 177, 405 (1!149). (11) G, R . FVyatt, N a l w e , 166, 237 (1950); Riocherrz. J., 48, 581 (1951). (12) It. D. Hotchkiss, J . Bid. Chem., 176, 315 (1948). (13) 8. C;. I,aland, \V. C. Overend and M. Webb, J . Cheni. SOC.,3224 (1952). (14) W. I<. Cohn, * J . Am. Cliem. Soc., 73, 1539 (1951). (15) G. R. Wyatt, Biochem. J., 48, 585 (1951). (16) C. A. Dekker and D. T. Elmore, J . Chem. Soc., 2864 (1951). (17) T. 1%. Johnson and R. D. Coghill, J . A m Chern. Soc., 47, 2838 (1925). (18) $3. Vischer, E. Chargaff and S. Zamenhof, J. Biol. Chem., 177, 429 (1949). (19) G. R. Wyatt and J. D. Smith, Biochem. J., 49, 144 (1951).
50
W. G . OVEREND AND M. S T A C E Y
product isolated from tubercle bacilli. Similarly, in a thorough examination of bacterial nucleic acids, Laland, Overend and WebbI3 have been unable to detect this desoxyribonucleoside among the constituents. Repetition of Coghill and Johnson’s work afforded a sample of tuberculinic acid which on chromatographic analysis gave no evidence indicative of the presence of 5-methylcytosine desoxyriboside. Although not a normal component of desoxypentose nucleic acids, the desoxyriboside of uracil has been obtained from an enzymic hydrolysis of a commercial sample of herring-sperm desoxypentose nucleic acid.20 Since the original nucleic acid contained no uracil and the cytosine desoxyriboside content of the hydrolyzate was much reduced, i t was assumed that the uracil desoxyriboside had been formed by an enzyme introduced by bacterial contamination. Such an enzyme (cytosine desoxyriboside deaminase) has been found to occur in extracts of cells of E. c o l i Z 1 I n these nucleosides, 2-desoxy-~-riboseis linked to position 9 of the purine bases or to position 3 of the pyrimidine bases.22 There is no conclusive evidence concerning the stereochemical disposition of the desoxyribose-base linkage, although FurburgZ3considers that desoxyribonucleotides may have the same shape as ribonucleotides. By x-ray analysis he confirmed that the sugar-base linkage in ribonucleotides is of the P-D-type. Hammarsten and colleagues24 have presented evidence from biochemical experiments which can be interpreted as indicating a P-D-configuration for the sugar-base linkage in desoxyribonucleotides. By separating the desoxypentose and pentose nucleic acids produced by rats after injection of labeled nucleosides, they found that cytidine was a good precursor for both types of nucleic acid. The pyrimidine ring of cytidine appeared in all the pyrimidines of both classes of nucleic acids, and so it seems that the rat is capable of converting D-ribose to 2-desoxyD-ribose when the sugar is linked to cytosine. This conversion, which must have occurred with the nucleoside linkage intact since cytosine itself is not utilized, provides further evidence that the glycoside linkage in the pyrimidine desoxyribonucleosides is a t position 3 of the base, as it is in the pyrimidine ribonucleosides. Furthermore, since pyrimidine ribonucleosides are P-D-glycosides, this interconversion points to a similar P-D-configuration for the desoxyribonucleosides since the possibility of a Walden inversion occurring a t carbon atom 1 during reduction at carbon atom 2 of the sugar, is seemingly remote.26 (20) (21) (22) (23) (24) (25)
C. A. Dekker and A. R. Todd, Nature, 166, 577 (1950). T . P. Wang, H. Z.Sable and J. 0. Lampen, J . Biol. Chem., 184, 17 (1950). J. M. Gulland and L. F. Story, J. Chem. Soc., 259, 692 (1938). S. Furburg, Acta Chem. Scand., 4, 751 (1950). E. Hammarsten, P. Reichard and E. Saluste, J . B i d . Chem., 183, 105 (1950). See J. Baddiley, Ann. Rev. Biochem., 20, 172 (1951).
CHEMISTRY O F T H E 2-DESOXYSUGARS
51
Until recently the lactol ring structure of 2-desoxy-~-ribosein nucleic acid had been proved conclusively only for the thymidine nucleoside component and in this case it was furanose in form.26 Subsequently Brown and L y t h g ~ e b, ~y ~application of the periodate oxidation procedure t o the 2'-desoxyribosides of guanine, hypoxanthine, cytosine and thymine, afforded proof of the presence of a furanose sugar in each compound. I n the past the isolation of 2-desoxy-~-ribosefrom desoxyribonucleic acid has proved to be very difficult. It was usual to degrade the nucleic acid by chemical methods to the constituent nucleosides, separate these, and then hydrolyze the glycosidic linkage and isolate the sugar portion. Separation of the nucleosides was a tedious procedure, and since acidic treatment for hydrolysis results in the conversion of some of the desoxypentose t o levulinic acid, yields were poor. Following attempts b y Thannhauser and Ottenstein,2swho employed picric acid for the hydrolysis of thymus nucleic acid and obtained diphosphoric esters of pyrimidine desoxyribosides, Levene and London29 resorted t o enzymic methods. A solution of thymus nucleic acid was passed through a segment of the gastrointestinal tract of a dog and collected from a n intestinal fistula. After incubation for several days, the desoxy-ribonucleosides of guanine, hypoxanthine (arising from deamination of adenine), cytosine and thymine, were isolated. Very mild hydrolysis of the guanine nucleoside gave the desoxy-sugar in crystalline form.30,31Similar mild acidic hydrolysis of hypoxanthine desoxyriboside gave a solution with the same optical rotation as an equivalent amount of 2-desoxy-~-ribose.29 Attempts t o isolate the sugar from the pyrimidine desoxyribonucleosides (i. e., thymine and cytosine desoxyribonucleoside) were unsuccessful, as the sugar was immediately converted into levulinic acid under the more drastic hydrolytic conditions necessary to cleave the linkage between the pyrimidine base and the d e s o x y s ~ g a r . ~ ~ Development of an enzymic hydrolysis by Klein32 afforded the possibility of preparing with comparative ease quantities of mixed nucleotides from desoxypentose nucleic acid, but the problem remained of obtaining the individual compounds in pure form by separation of the mixture. The development of chromatographic methods and of ion(26) (1935). (27) (28) (29) (30) (31) (32)
P. A. Levene and It. S. Tipson, Science, 81,'38 (1935); J. B i d . Chern., 109, 623 D. ILI. Brown and B. Lythgoe, J . Chern. Soc., 19'30 (1950). S. J. Thannhauser and B. Ottenstein, Z . physiol. Chem., 114, 17, 39 (1921). 1.' A. Levene and E. S.London, J. BioZ. Chem., 83, 793 (1929). P. A. Levene and T. Mori, J . Biol. Chern., 83, 803 (1929). P. A. Levene, L. A. Mikeska and T. Mori, J . Biol. Chern., 86, 785 (1930). W. Klein, 2. physiol. Chem., 218, 164 (1933).
52
W. G. OVEREND AND M. STACEY
exchange resins has solved this problem and it is now possible to isolate from enzymic digests of desoxypentose nucleic acids, desoxyribo-nucleotides and -nucleosides in greatly improved yield and in a high degree of purity. By chromatographic separation on a column of alumina, SchindleP was able to obtain the desoxyribosides of guanine, hypoxanthine, thymine and cytosine in reasonable amounts from an enzymic hydrolyzate of sodium thymonucleate. Chromatography on Dowex-50 and starch was also effe~tive.~4According to Volkin, Khym and C ~ h n , ~ ~ the separation in good yield of desoxyribonucleotides on ion-exchange resins is achieved “speedily and with precision under mild conditions.” Other workers36 have described similar experiences with this method. By very mild hydrolysis of the purine desoxyribonucleosides which had been separated by ion-exchange resin chromatography, the writers and colleague3’ have been able to isolate 2-desoxy-~-ribosein fair yield. Enzymic evidence has been provided38 to show that the desoxyribonucleotides isolated by the above methods are esterified by phosphoric acid a t carbon atom 5 of the sugar moiety. Consequently there is also the possibility that in the near future 2-desoxy-~-ribose &phosphate will be obtainable from nucleic acid by application of the above methods. Kent39 demonstrated that mercaptanolysis of desoxyribonucleic acids resulted in the liberation of the sugar, which was isolated as the dibenzyl mercaptal. A unique 3-desoxysugar has been isolated and characterized by Spring and his coworkers.40 It is named cordycepose, as it is obtained together with adenine by acidic hydrolysis of cordycepin, a crystalline metabolic product isolated from the culture solutions of Cordyceps militaris (Linn.)Link. Cordycepin has antibiotic properties and inhibits the growth of many strains of Bacillus subtilis. Cordycepose has been shown t o be a 3-desoxysugar with a branched carbon chain, and the structure assigned to it is as shown in VIII.4l Obviously it is closely related chemically to apiose (IX),42a sugar which occurs in parsley. In (33) 0. Schindler, Helv. Chim. Acta, 32, 979 (1949). (34) P. Reichard and B. Estborn, Acta Chem. Scand., 4, 1047 (1950). (35) E. Volkin, J. X. Khym and W. E. Cohn, J . A m . Chem. SOC.,73, 1533 (1951). (3G) R. L. Sinsheimer and J. F. Koerner, Science, 114, 42 (1951); see also, W. Andersen, C. A. Dekker and A. R. Todd, J . Chem. SOC.,2721 (1952). (37) S. G. Laland, W. G. Overend and M. Stacey, unpublished results. (38) C. E. Carter, J . Am. Chem. SOC.,73, 1537 (1951). (39) P. W. Kent, Nalure, 166, 442 (1950). (40) K. G. Cunningham, S. A. Hutchinson, W. Manson and F. S. Spring, J . Chem. Soc., 2299 (1951). (41) H. R. Bentley, K. G. Cunningham and F. S. Spring, J . Chem. Soc., 2301 (1951). (42) C. S. Hudson, Advances i n Carbohydrate Chem., 4, 57 (1949).
CHEMISTRY OF THE
2-DESOXYSTJGARS
53
addition to relatively common sugars, as for example D-glucose and L-rhamnose, much rarer sugars are also found as components of the cardiac glycosides. These rarer sugars are frequently 2-desoxyhexomethyloses, the majority of which have a methyl ether grouping at posi-
tion 3. Details concerning the isolation and characterization of these sugars, together with literature references, were described by Elderfield' in Volume I of this series; consequently, for further information the present authors refer readers to that account. IV. DETECTION 1. Introduction
I n addition t o the usual tests employed for the detection of carbohydrates, other reactions have been introduced which are designed to detect specifically 2-desoxy-pentoses and -hexoses. In particular many of these tests have aimed a t the detection of 2-desoxyribose and at its differentiation from ribose, since these two sugars occur naturally in the desoxypentose and pentosenucleic acids. Many of the procedures nowadays employed for the detection of 2-desoxyribose have been applied directly t o biological materials. I n attempts to elucidate the mechanisms of these tests, data have been discovered not only about the behavior of 2-desoxyribose1 but also about 2-desoxypentoses generally. For this reason these tests will be described in some detail. Likewise the occurrence naturally of some 2-desoxyhexomethyloses, as components of certain cardiac glycosides, has stimulated attention towards the need for specific tests for their detection. The following account describes some of the more common tests which have been deveIoped. 3-Desoxysugars, being of less importance, have not been studied extensively and specific tests for their detection have not been developed, as far as we are aware. 2. Iliphenylamine Reaction D i s ~ h describes e~~ a reagent consisting of a mixture of diphenylamine, acetic acid and concentrated sulfuric acid which on being heated under carefully controlled conditions with solutions of desoxyribonucleic acids (43) Z. Dische, Mikrochetnie, 8, 4 (1930).
54
W. 0. OVEREND AND M. STACEY
gives an intense blue coloration. Replacement in the reagent of concentrated sulfuric acid by either trichloro- or trifluoro-acetic acid results in no color formation when the test is carried out in the usual manner. Substitution of concentrated sulfuric acid by concentrated hydrochloric acid afforded some color when the reagent was heated with desoxyribonucleic acid, but this color was less intense than that obtained with the of normal reagent.44 When suitable concentrations ( e . g., 0.024.20/,) desoxyribonucleic acid were used with the normal reagent, the intensity of the blue color appeared to be proportional to the amount of desoxyribonucleic acid present. As commonly employed, the test is not suitable for the estimation of pyrimidine deso~yribosides~~ and it has been noted by M i r ~ k ythat ~ ~ the diphenylamine reaction enabled estimations to be made of purine desoxyribosides exclusively. If, however, thymidine and desoxy-cytidine are given a preliminary treatment with bromine there is a marked increase in color development with thymidine and a lesser increase with desoxy-cytidine on treatment with the diphenylamine reagent.47 The color obtained with brominated thymidine approaches in intensity that obtained with desoxy-inosine. Since the development of color, compared with its production from purine desoxy-ribosides, is more gradual it is usual to extend the period of heating to thirty minutes. The test depends on the 2-desoxyribose component of the nucleic acid and in experiments directed towards the synthesis of this sugar and its derivatives, the diphenylamine reaction has been used to obtain indications of the formation of the required product. Originally it was claimed that the test was specific for 2-desoxyribose but more recent investigations by Stacey and his coworkers4shave shown that the test is given by 2-desoxypentoses generally. Moreover, these workers have elucidated in part the mechanism of the test.48 These studies will be discussed more fully subsequently. Owing to the important role which desoxyribonucleic acids play in the nucleal materia146~49~50 of cells and the necessity for their detection and accurate estimation and more particularly the need for their differentiation from ribonucleic acids, the test has been investigated intensively. (44) W. G. Overend, J . Chem. Soc., 1484 (1951). (45) W. C. Schneider, J . B i d . Chem., 161, 293 (1945). (46) A, E. Mirsky, Advances in Enzymol., 3, 1 (1943). (47) T. G. Brady and E. McEvoy-Bowe, Nature, 168,299 (1951). (48) R. E. Derias, M. Stacey, Ethel G. Teece and L. F. Wiggins, (a) Nature, 167, 740 (1946); (b) J . Chem. SOC.,1222 (1949). (49) A. E. Mirsky and A. Pollister, froc. Natl. Acad. Sci. U . S., 28, 344 (1942). (50) 0.T. Avery, C. M. MacLeod and M. MoCarty, J . Exptl. Med., 79, 137 ( 1944).
CHEMISTRY O F THE 2-DESOXYSUQARS
55
It was adapted by Sevag and coworkers61for the determination of desoxyribonucleic acids in cellular material. The validity of such determinations is doubtful, however, since O ~ e r e n d 4has ~ demonstrated that amino acids affect the intensity of the blue color developed. Seibertb2varied the method slightly to account for colors due to impurities in the solution to be analyzed, and Douncefi3took additional precautions in minimizing turbidities in the colored solution. The elimination of turbidities by means of preliminary enzyme hydrolysis, before the estimations, has been employed for tissues and vaccinia1 elementary bodies.64 It was noted by Stacey and that if the diphenylamine reagent contained higher concentrations than usual of sulfuric acid, certain keto sugars give a blue color apparently similar to that given by 2-desoxyribose in the standard test. These workers were able to introduce a modification which overcame this difficulty. Certain anomalous purple colors are given by some materials which contain carbohydrate.66 These colors may well obscure, or otherwise be mistaken for, a positive diphenylamine test, and PirieS8has emphasized that great care must be exercised in interpreting the results of the test. Nevertheless, in spite of the above anomalies, the diphenylamine reaction is still probably the most specific test available for the detection of desoxyribonucleic acid and 2-desoxyribose. Stacey and his coworkers48submitted a wide range of carbohydrate derivatives to the precise conditions of the diphenylamine test and found that in general the color reactions obtained could be classified into four categories. The following were typical : aldopentoses, aldohexoses, disaccharides (such as maltose and lactose), polysaccharides (such as starch and glycogen) and many esters and ethers of these substances gave no coloration. Aldehydes and ketoses gave a green coloration. Hexals (e. g., D-glucal) gave a pink to violet color and the characteristic blue color given by desoxyribonucleic arid was only afforded by ZdesoxyD- and -L-ribose, D- and L-arabinal and furfuryl alcohol. It was known that arabinal (X) can readily be transformed into 2-desoxyribose (XI) by and both furfuryl aIcohol (XII)58and 2-desoxyribose (XI)30 (51) M. G. Sevag, J. Smollens and D. B. Lackmann, J. BioZ. Cheni., 134, 523 (1'340). (52)Florence B. Seibert, J. Bid. Chem., 133, 593 (1940). (53)A. L. Dounco, J . Biol. Chem., 161, 221 (1943). (54) C.L. Hoagland, G. I. Lavin, J. E. Smadel and T. M. Rivers, J. E'zptl. Med., 72, 139 (1940). (55) S. S. Cohen, J. Biol. Chem., 106, 691 (1944). (56) If. W.Pirie, Brit. J . Exptl. Path., 17, 269 (1936). (57) J. Meisenheimer and H. Jung, Ber., 60, 1462 (1927). (58) R. Pummerer and W. Gump, Ber., 66, 999 (1923).
56
W. G. OVEREND AND M. BTACEY
yield levulinic acid (XIV; methyl ester) as the end product of acid hydrolysis. Since levulinic acid gives a completely negative diphenylamine test, search was made for a common intermediate in the conversion of X, X I and XI1 into XIV. Pummerer and his ~ o w o r k e r shave ~~~~~ shown that furfuryl alcohol (XII) can be converted by 0.1 percent methanolic hydrogen chloride into w-methoxylevulinaldehyde dimethyl acetal (XIII), which on further hydrolysis with 2 percent methanolic hydrogen chloride is converted into methyl levulinate (XIV). It was demonstrated that 2-desoxyribose (XI) could be converted into XIII by heating at 180" in a sealed tube with 0.1 percent methanolic hydrogen chloride; XI11 gives an intense blue color with the diphenylamine reagent. CH-CH
\
/OH CH
'C 0 II'HXI1 C-CH,OH II
HAOH A H
;Ar
c I -q
.
q
CHIO
CHaOCH&O-CH&H&H(OCHs)n
XI11 1'2 % MeOH/HCl
CH&O-CH&H&O&HI XIV
In Fig. 1, absorption curves with a characteristic band due to the Dische color, with the maximum at X = 5800 A, are shown, and it is obvious that the most intense color is given by XIII. It appears that any substance which, under the conditions in which the diphenylamine test is carried out, can be converted into XI11 will give a blue color with the reagent. Hence the test is not specific for 2-desoxyribose and is given generally by 2-desoxypentoses since it has been shown that 2-desoxyxylose and xylal both give a blue color with the reagent'O (see Fig. 2). 3-Desoxy- and 2,&didesoxyribose and derivatives thereof, also give faint blue colors with the diphenylamine reagents1 but in these cases it is necessary to heat for a longer time than is usual. Woodhouses2recom(59) R. Pummerer, 0. Guyot and L. Birkofer, Ber., 68, 480 (1935). (60) W. G. Overend, A. F. Shafiradeh and M. Stacey, J . Chem. SOC.,1027 (1950). 255 (1952). (61) R. Allerton, W. G. Overend and M. Stacey, J . Chem. SOC., (62) D. 1,. Woodhouse, Brit. J . Cancer, 3, 510 (1949).
CHEMISTRY OF THE 2-DESOXYSUGARS
57
mends longer heating as a standard procedure, claiming that more reproducible results are obtained thereby. Very little is known about the nature of the reaction-products resulting from the interaction of w-hydroxylevulinaldehyde and diphenylamine. Stacey and his coworkers4* compared oxidation products of diphenylamine with products isolated from the reaction, and concluded that the
4000in 360C
A,
A
FIG. 1.-Curves for Light-absorption in the Dische Test; ( a ) 2-Desoxy-~-ribose; D-Arabinal; ( b ~ L-Arabinal; ) (c) Furfuryl alcohol; ( d ) o-Methoxylevulinaldeliyde Dimethyl Acetal; ( e ) Sodium Thymonucleate; (f) Methyl 2-desoxy-p-~-ribopyranoside; (g) Methyl 3,4-Dimethyl-2-desoxy-P-~-ribopyranoside. (bl)
substance responsible for the blue coloration was not identical with diphenylbenzidine-violet. Attempts were made to isolate on an alumina column the substance responsible for the blue coloration, but it was not possible to identify this coloration with the presence of a single condensation product of the secondary amine. Because of these results the Dische reaction is unlikely t o be of high reliability in the absolute quantitative sense. Cohenb5 discussed the diphenylamine reaction on the basis of his
58
W. G. OVEREND AND M. BTACEY
hypothesis of the mechanism of the tryptophan test. Although the colors that are produced in the diphenylamine reaction at 100" do not fit this hypothesis, the same reaction at room temperature over extended periods produced colors with 2-desoxyribose1 furfural and benzaldehyde which possess a similar shift of the absorption maximum in the visible range. Thus 2-desoxyribose gives a reddish-purple color, furfural a 3600
2800 E
2000
1200
400 I
4200
I
1
1
5000
I
5800
A,
I
1
6600
A.
FIG.2.-Curves
for Light-absorption in the Dische Test; (A) 2-Desoxy-~-xylose; ( B ) D-Xylal; (C) a-Methoxylevulinaldehyde Dimethyl Acetal.
green color and benzaldehyde a blue coIor. This suggests that the heating procedure in the diphenylamine reaction as commonly carried out results in some course of events that is more complex. 3. Tryptophan Reaction
C ~ h e nintroduced ~~ the tryptophan reaction for the detection and estimation of desoxyribonucleic acids. Since the reaction is given equally well by 2-desoxyribose1 the test obviously depends on this component of the nucleic acid. It is likely that this test is given generally by 2-desoxypentoses. In the recommended procedure the suspected nucleic acid is heated at 100' for 10 minutes with tryptophan and 30 percent (final concentration) perchloric acid, and in a positive test there is a rapid development of a red color. Quantitative estimations can be carried out
CHEMISTRY O F THE 8-DESOXYSUQARS
59
by measuring the intensity of the color that is developed, in a photoelectric colorimeter with filters having a transmission range of 485-550 mp. Using desoxyribonucleic acid solutions (with concentrations ranging from 0.1 to 0.5 mg. per ml.) it was demonstrated that there is a linear relationship between concentration and the intensity of the color developed; the maximum difference in duplicate determinations was 2.5 percent. Of a series of reagents tested, perchloric acid proved t o be the most useful, both for the hydrolysis of all types of nucleosides and for aiding the condensation of desoxyribose and other aldehydic substances with tryptophan. According to S c h ~ i e i d e rthe ~ ~ sensitivity of the method is enormously increased if the fluorescence of the heated solutions is measured. Straight-line relationships were found to exist between the concentration of the desoxyribonucleic acid (even when as low as 0.5 to 2 . 5 ~ )and the intensity of the fluorescence. This fluorescence is characterized by a sensitivity to ultra-violet light and it decreases in intensity considerably on prolonged exposure to such radiation. In the tryptophan reaction, aldehydes and fructose derivatives are among the most important interfering substances. Proteins interfere with the test, but C o h e ~ eliminated i~~ complications due to such interference, and hence increased the value of the test, by developing a method for extracting the colored reaction-product of desoxyribose and tryptophan without simultaneous extraction of other reaction-products. I n addition to tryptophan, P-methylindole, indole-3-acetic acid and indole-3-propionic acid were tested under identical conditions and molar concentrations. The intensities of the color developed with 30 percent perchloric acid alone were in the order : tryptophan < indole-3-acetic acid < indole-3-propionic acid < p-methylindole. The first three of these indole derivatives produced red condensates with desoxyribose in perchloric acid, that due to indole-3-acetic acid being markedly less than that arising from the other two. Examination of the absorption spectra, i n the visible range, of alcoholic extracts of the reaction-products revealed that that from tryptophan was the simplest. Hence it appears that tryptophan is the most satisfactory readily-available Bindole derivative for use in the estimation of 2-desoxyribose and probably also of other 2-desoxypentoses. Cohen55has forwarded a hypothesis to describe the observed effects in this test. Any hypothesis must account for the specificity of the reaction for deaoxyribose as contrasted t o ribose, the roles of tryptophan and perchloric acid in the reaction, and the shift in absorption maximum observed between the desoxyribose and furfural condensates. (This latter observation indicates that the tryptophan reaction is not due t,o
60
W. G . OVEREND AND M. STAGEY
the conversion, of all substances giving a positive test, into a common intermediate such as w-hydroxylevulinaldehyde or hydroxymethylfurfural, which would enter into reaction with tryptophan.) Cohen’s explanation of the observed effects was based on the Amadoria3rearrangement in which the cation of the Schiff’s base form of a nitrogen glycoside (XV) becomes rearranged to give substances of the general formulas XVI and XVII. It is apparent that in this system the condensation with tryptophan, of carbohydrates with a free hydroxyl group at carbon atom 2 (i. e., XV and XVI, R”’ = -OH) will not increase the number
+
RNR’
I1
HC HA,‘’‘
I
R” XV
RNR’
RNR’
- A‘’
--H+Hb H L AR’‘t -+
I R”
XVI
XVII
of conjugated double bonds in proceeding to the ketone XVII. However, in this conversion 2-desoxy derivatives of the sugars will be unable to proceed beyond the stage represented by XVI (R”‘= H) and will exist in equilibrium with derivatives represented by the general formula XV (R”’ = H). Thus 2-desoxyribose, furfural and benzaldehyde yield reaction products with tryptophan represented by XVIII, XIX and XX, which are colored red, green and blue respectively. They contain one, three and four additional double bonds conjugated to the indole
3s” N+
8,,
HObH
A
b’I1
‘CH
CH-CH
I1
HO,H CH~OH XVIII
XIX (R = -CHg-CH-CO*OH)
XX
I
N&
nucleus and hence the direction of shift of the absorption maximum is in agreement with the increase in conjugated double bonds. (63) M. Amadori, Atli reale accad. nag. Lincei, 2, 337 (1925); 13, 72, 195 (1931).
CHEMISTRY OF THE 2-DESOXYSUQARS
61
The perchlorates of various secondary amines, such as diphenylamine and indole derivatives, are colorless.64 The similarity of colors produced in the presence of hydrochloric acid also attests to the non-auxochromic character of the perchlorate ion in the production of the colored derivative. Consequently, the only role attributable to the perchloric acid in this test is that with nucleic acids it leads t o more effective hydrolysis and releases more 2-desoxyribose for reaction with tryptophan. This reaction leads to the production of a substance of the type represented by XV and XVI (R”’ = H), and the increase in the number of conjugated double bonds results in the product being colored. With ribose, which has a free hydroxyl group at carbon atom 2, a ketone of the type shown in XVII can be formed, and in this case the net result is no increase in the number of double bonds conjugated with the indole nucleus and no comparable increase in color. Hence the test will distinguish between ribose and 2-desoxyribose. 4. Feulgen Reaction Feulgen and R o ~ s e n b e c kintroduced ~~ a test for the detection of desoxyribonucleic acid which has been extensively used in cytochemical work. It is usually considered that the carbohydrate portion of the nucleic acid is reponsible for the test. Many modifications of the original technique have been made, but the procedures most frequently employed are those developed by de Tomasi66 and by St0well.~7 Essentially the reaction consists of two parts: a short hydrolysis of the nucleic acid with N hydrochloric acid heated to GO”, followed by reaction of the product with leucofuchsiri to produce a magenta colored compound. Neither unhydrolyzed desoxyribo- or ribo-nucleic acids give this reaction, but it is given non-specifically by aldehydes and its use is contra-indicated unless special precautions have been taken to eliminate such interfering compounds. Divergent views exist concerning the deductions to be drawn from results obtained by using the Feulgen In part these misunderstandings are due to incomplete evidence about the reactions involved. (64) K. A. Hofmann, A. Metaler and I<. HGbold, Rer., 43, 1080 (1910). (65) R. Feulgen and H. Rossenbeck, 2. physiol. Chem., 136, 203 (1924). (66) J. A. de Tomasi, Stain Technol., 11, 137 (1936). (67) R. E. Stowell, Stain Techno/., 20, 45 (1945): rf. C.Widstrom, Biochem. Z., 199, 298 (1928). (68) J. F. Danielli, (a) Nature, 167, 755 (1946); (b) S y m p . Soc. Ezptl. Biol., 1, 101 (1947); ( c ) Quart. J . Microscop. Sci., 90, 67 (1949). Natl. Acad. Sci. U.S., 34,75 (1948); Chromosoma, 3, (69) H. S. Di Stefano, PTOC. 282 (1948). (70) E. Stedman and Ellen Stedman, Symp. Soc. Ezptl. Biol., 1, 232 (1947); Biochenb. J . , 47, 508 (1950).
62
W. G . OVEREND AND M. STACEY
The general view is that acid hydrolysis breaks the purine-sugar glycosidic linkage in desoxyribonucleic acid, enabling the 2-desoxypentose to exist to some extent in its straight-chain aldehydo form. In this form it can react with Schiff’s reagent,71 forming a reddish colored compound. This general view contains many assumptions. For example, it is assumed that in this test 2-desoxyribose would react, to some extent at least, in its aldehydo form with Schiff’s reagent and that under the test conditions only purine bases are cleaved from the nucleic acid. Moreover, it is assumed that the color developed is not due to the desoxypentose decomposing in the acid medium to yield w-hydroxylevulinaldehyde (cf. diphenylamine test) which could react with Schiff’s reagent to give a soluble dye. In the test this soluble dyestuff could be adsorbed from solution onto protein material. The validity of some of these assumptions has been investigated by O ~ e r e n d . The ~ ~ intensities of the colors produced by normal hexoses and pentoses and their 2-desoxy analogues, when Schiff’s reagent was added to them, were measured quantitatively. Strict controls of temperature and air-contamination were maintained since both affect the intensity of the Schiff’s color. Results obtained with D-ghcose, D-galactose, n-ribose and their Zdesoxy analogues, showed that in all cases the desoxysugar gave a color of much greater intensity. The effect was most pronounced in the hexose series and it was observed that 2-desoxy-D-galactose gives a more intense color than 2-desoxy-~-glucose. I n this connection it is noteworthy that other derivatives of D-galactose are known (e. g., 3,6-anhydro-~-galactose) which exist predominantly in the aldehydo form.?a The sugar component of desoxyribonucleic acid is fixed in the furanose form26~27~74 and so the effect on the intensity of the color developed, by preventing the above sugars from existing in the pyranose form, was investigated. This was achieved by suitable protection of the hydroxyl group at carbon atom 5 in these sugars. It was found that if the sugars can exist only in furanose or aldehydo forms, the intensity of color developed when Schiff’s reagent is added is much enhanced. n-Glucofuranose 5,6-m0nocarbonate~~ and 2-desoxy-D-glucofuranose 5,6-m0nocarbonate~~ for example, both show more intense colors than do D-glucose and 2-desoxy-~-g~ucose respectively, when treated according to the test procedure. Similarly, 3,5-dimethyl2-desoxy-~-ribofuranosegave a more intense color with the reagent than (71) H . Schiff, Ann., 140, 102 (1866). (72) W. G. Overend, J . Chem. Soc., 2769 (1950). (73) W.N. Haworth, J. Jackson and F. Smith, J . Chem. Soc., 620 (1940). (74) K. Makino, Biodem. Z., 282, 263 (1935). (75) W.N.Haworth and C. R. Porter, J . Chem. Soe., 2796 (1929). (76) I. W.Hughes, W. G. Overend and M. Stacey, J . Chem. Soc., 2846 (1949).
CHEMISTRY OF THE 8-DESOXYSTJGARS
63
did 3,4-dimethyl-2-desoxy-~-ribopyranoseand both of these sugars gave more intense colors than derivatives of n-ribose. The most intense color obtained in the experiments was with a sugar which could exist only in its aldehydo form, namely diethylidene-aldehydo-L-xylose, indicating that the development of color is associated with the aldehydo form of the sugar. The outcome of these experiments demonstrated that 2-desoxysugars give a much more intense color with Schiff’s reagent than do their normal analogues under comparable conditions, an effect enhanced if they are prevented from existing in the pyranose form. A consequence of these measurements is that even if the sugar-base glycosidic linkages in ribonucleic acid are cleaved during the Feulgen test, the freed reactive group at carbon atom 1 of the sugar and Schiff’s reagent do not react t o give a compound colored as intensely as that which results from similar treatment of desoxyribonucleic acid. According to O ~ e r e n d , ’ the ~ intensity of color developed may also be influenced by the phosphate ester substituents on the desoxysugar. For the reaction between a simple aldehyde and Schiff’s reagent it has been postulated7’ that a complex is formed between two molecules of the aldehyde and the fuchsin-sulfurous acid reagent and there is evidence to support this idea.78~7~ In the Feulgen test, O ~ e r e n dhas ~ ~provided data which indicate that a reaction occurs between the available reactive group at carbon atom 1 of the desoxypentose and Schiff’s reagent. Furthermore, a preliminary examination of the bases liberated in the Feulgen test indicated that these were the purine bases, adenine and guanine, with only very slight amounts of pyrimidine bases. Li and Staceyso succeeded in isolating the purine bases in crystalline form. It is well known that if there is over-hydrolysis inlthe Feulgen test, the intensity of the color developed is much reduced. Lately, renewed interest in this effect has led to several interpretations being f o r ~ a r d e d . ~ ~ ~ ~ The work of Stacey and his coworkers on the properties and reactions of desoxy-pentoses and -hexoses and in particular of 2-desoxy-~- and -L-ribose, indicates that over-hydrolysis of the nucleic acid not only brings it into a more diffusible form, but also changes the desoxypentose (77) H. Wieland and G. Scheuing, Ber., 64, 2527 (1921). (78) P. Rumpf, Ann. chim. (Paris), 3, 327 (1935). (79) R. L. Shriner and R. C. Fuson, “The Systematic Identification of Organic Compounds,” John Wiley and Sons, New York, 1944, pp. 62-63. (80) Chong-fu Li and W. Stacey, Nature, 163, 538 (1949). (81) H. Bauer, Z. Zellforsch., 16, 225 (1932). (82) B. B. Hillary, Botan. Gaz., 101, 276 (1939).
64
W. Q. OVEREND AND M. STACEY
to some extent into o-hydroxylevulinaldehyde. S t a ~ e y ~tentatively ~(~) suggested that this aldehyde was responsible for the development of color in the normal Feulgen test, but this suggestion was criticized by Danielli.ss(b) There is little doubt, however, that if the time of hydrolysis is extended this compound would be formed, and if in staining procedures washing was not exhaustive, a colored compound would be obtained on addition of Schiff’s reagent, The overall effect of carrying out the Feulgen test on solutions containing only nucleic acids seems to be that mainly the purine-sugar linkages are cleaved, and the desoxysugar can then react to some extent in its aldehydo form and so combine with Schiff’s reagent t o give a colored complex. This effect is probably intensified by the fact that the sugar is prevented from coexisting in its pyranose form. When the Feulgen procedure is carried out on cells or tissue sections, other factors need consideration. It is conceivable that materials occur in cells which could give a color with Schiff’s reagent.88 Moreover, proteins are likely to influence to some extent the formation of the colored comp l e ~since , ~ ~Sibatanis6 reports that the presence of histones increases the intensity of the Feulgen color. This remarkable color-enhancing effect is, however, by no means confined to histones, for proteins such as eggalbumin, casein, ribonuclease (and also lanthanum chloride) exhibit similar properties. Methods for the quantitative estimation of desoxyribonucleic acids, based on the Feulgen nucleal reaction have been reported,*8but because of factors like the color-enhancing effects, these methods must be accepted with reservations.87 5. Other Methods
Gurin and Hood88 have demonstrated that addition of a solution of carbazole to an ice-cold mixture of sulfuric acid and 2-desoxyribose results in the formation of an intense yellow color. This test, however, is not aa suitable as the diphenylamine reaction for the detection and estimation of Z-desoxyribose. It is markedly unspecific since sulfuric (83) See J. F. Lhotks and H. A. Davenport, Stain Technot., 26, 35 (1951) for a discussion of this subject. (84) Y. Hamazaki, Nissin Zgaku Tokyo, 28, 46 (1939). (85) A. Sibatani, Nature, 166, 355 (1950);see also, A. Sibatctni and M. Fukuda, Biochim. Biophys. Ada, 10, 93 (1953). (86) H. Ris snd A. E. Mirsky, J . Gen. Physiol., 33, 125 (1949). (87) See J. 0.Ely and M. H. Rose, And. Record, 104, 103 (1949)for a discussion of some of these reservations. (88) S. Gurin and D. B, Hood, J . Biol. Chem., 131, 211 (1939);139, 775 (1941).
CHEMISTRY O F T H E 2-DESOXYSUGARS
65
acid, of the concentration prescribed, converts most carbohydrates into products which will form some colored substances with carbazole. Moreover, when carrying out the test, there are often evident signs of decomposition of the sugar. Although the method has been used,46 it is not reliable for estimating the nucleic acid content of mixtures, using either 2-desoxyribose or 2-desoxyguanosine as a standard material. IJnlike results with the diphenylamine test, there is a partial hydrolysis of pyrimidine desoxyribosides. The reaction of cysteine and sulfuric acida9with 2-desoxyribose has also been used for the estimation of desoxyribonucleic acids.90 Riboiiiicleic acids do not interfere but fructose derivatives give slight yellow colors. In the cysteine-sulfuric acid reaction, cytosine desoxyriboside does not behave in the same manner as either the free desoxypentose or guanine desoxyriboside, hypoxanthine desoxyriboside, or thymidine, since the color obtained is considerably less intense than that formed in this reaction by a corresponding amount of 2-desoxy-~-ribose.~' Only aldehydes with an a-methylene group (i. e., R.-CH&HO) condense with 3,5-diaminobenxoic acid to form quinaldines.92 Consequently, in the carbohydrate series only 2-desoxysugars will react. The usual procedure adopted is to add to the unknown sugar solution an equal volume of a 1.3 percent solution of 3,5-diaminobenzoic acid hydrochloride in 50 percent aqueous perchloric acid. If the carbohydrate solution contains a 2-desoxysugar it will assume a yellow color with a green fluores~ence.~3Use of an ester instead of a salt of 3,5-diaminobenzoic acid reduces the sensitivity of the test. Attempts have been made to estimate 2-desoxyribose by the orcinol reacti0n'4-~7 for pentoses, but in the test the desoxysugar is mainly converted into levulinic acid which gives no color with the reagent. Consequently, in tests for nucleic acids the intensity of the color given by desoxyribonucleic acid corresponds to only about one eighth of that obtained with the same quantity of ribonucleic a ~ i d . ~ ~ ~ ~ ~ . ~ ~ (89) Z. Dische, Proc. Soc. Ezptl. Biol. Med., 66, 217 (1944). (90) P. K. Stumpf, J . Biol. Chem., 169, 367 (1947). (91) L. A. Manson and J. 0. Lampen, J . Biol. Chem., 191, 87 (1951). (92) L. Velluz, G. Amiard and M. Pesea, Butl. sac. chim. France, 16, 680 (1948). (93) M. Pesez, Bull. SOC. chim. biol., 32, 701 (1950). (94) E. W. Allen and B. Tollens, Ann., 260, 305 (1890). (95) M. Bial, Deut. med. Wochschr., 28, 253 (1902); 29, 477 (1903); Biochem. Z . , 3, 323 (1907). (96) Z. Dische and K. Schwarz, Mikrochim. Acta, 2, 13 (1937). (95) W. Mejbaum, 2.physiol. C h m . , 268, 117 (1939). (98) L. Hahn and H. von Euler, Svensk Vit. Akad. Ark. f. Kemi A . , 22, No. 23 (1946);Svensk Kern. Tidskr., 68, 251 (1946).
66
W. CT. OVEREND AND M. STACEY
Turchini and Gosselin de Beaumonts9 reported the use of 9-phenyl(or 9-methyl-)2,6,7-trihydroxy-3-fluoronefor the differential staining of ribo- and desoxyribo-nucleic acids. The former gives rise to a yellowpink color and the latter t o a bluish-violet tint. It is necessary to hydrolyze the nucleic acid since it is the pentoses thereby liberated which yield the color, indicating that the reagent differentiates between ribose and its 2-desoxy analogue. The Dreywoodlooanthrone reagent, which gives a positive qualitative test for a large variety of carbohydrates, as well as for furfural and its 5-hydroxymethyl derivative, gives a negative test for 2-desoxyribose.lol During their investigations with digitoxose, Kellerlo2and Kilianilo3 found a testio4which is general for 2-desoxyhexoses. As usually carried out, the test consists in layering concentrated sulfuric acid with a solution of a few milligrams of the substance in glacial acetic acid containing iron sulfate. The production of a deep blue ring at the interface, with the color gradually diffusing into the upper layer, is taken as a positive test. It should be emphasized that this test is not specific for 2-desoxysugars, but is given also by other substances, notably certain indole derivatives.l Fort,unately, these are not likely t o be confused with carbohydrates. This test has been extensively used during investigations of the carbohydrate components of certain cardiac glycosides. A spot test sometimes employed is the pine shaving test. A pine splinter is impregnated with a solution of the sugar and exposed t o warm vapors of aqueous hydrogen chloride. If a 2-desoxysugar is present the splinter is turned dark green. Recently, color tests have been found by which desoxysugars may be distinguished from other sugars or sugar derivatives on paper chromatograms. Io4.
V. SYNTHESIS OF %DESOXYSUGARS 1. Riosynthesis
As a component of desoxypentosenucleic acids, the synthesis of desoxyribose must play an important part in the metabolism of cell (99) J. Turchini and L. A. Gosselin de Beaumont, Arch. SOC.Sci. Med. Biot. Montpellier et Languedoc, 2s-24, 599 (1943); Bull. Hislol. Appl. Physiol. Path. Tech. Microscop., 21, 124 (1944);Compt. rend., 189, 584 (1945). (100) R.Dreywood, Ind. Eng. Chem., Anal. Ed., 18, 499 (1946). (101)L. Sattler and F. W. Zerban, J. Am. Chem. SOC.,72, 3814 (1950). (102) C. C.Keller, Bey. Pharm. Ges., 275 (1895). (103) H.Kiliani, Arch. Pharm., 234, 273 (1896); 261, 562 (1913); Ber., 88, 4040 (1905). (104) See A. W. van der Haar, “Monosaccharide und Aldehydsauren,” Borntraegen Geb., Berlin, 1920,p. 10. (104e) J. T,Edward and Deirdre M. Wddron, J . Chem. Soc., 3631 (1952).
CHEMISTRY OF THE
2-DESOXYSUGARS
67
nuclei. The suggestion was forwarded by Hough and Joneslob that desoxypentoses may arise from the aldol-type condensation of acetaldehyde and glyceraldehyde, and essentially this could be correct. It has been demonstrated that a condensation of this type leads t o the formation of a desoxypentose, since acetaldehyde reacts with 2,%isopropylidene-~glyceraldehyde in the presence of potassium carbonate to yield some 4,5-isopropylidene-2-desoxy-~-ribose~~~ (see page 84). Racker'O' has deduced evidence which indicates a similar route for the enzymic synthesis of desoxypentose from triose phosphate and acetaldehyde. Extracts of E. coli, C . diphtheriae and S . fecalis, prepared by sonic disintegration of the bacterial cells or by grinding with alumina, are capable of catalyzing the reversible reaction: Glyceraldehyde phosphate
+ acetaldehyde
desoxypentose phosphate
The heat-labile enzyme which catalyzes this aldol condensation was purified eightfold from the extracts of E. coli. By combining this phosphodesoxyriboaldolase with purified phosphoriboaldolase from yeast, was able t o demonstrate the long sought conversion of D-ribose into desoxy-D-ribose, e. g., (2 enzymes)
n-Ribose 5-phosphate + desoxy-D-ribose 5-phosphate (+ acetaldehyde) (+ glyceraldehyde)
It is apparent that a triose phosphate is the commoii intermediate between D-ribose and Zdesoxy-D-ribose in metabolism. No experimental data are available concerning the biosynthesis of 2-desoxyhexoses. The naturally occurring 2-desoxyhexomethyloses (XXII) could be formed, possibly, by condensation of two molecules of acetaldehyde (which can arise from oxalacetic acid or pyruvic acid) and one molecule of glycol aldehyde-that is, from 4-desoxytetroses (XXI) and acetaldehyde. Similarly, 3-methyl-2-desoxyhexomethyloses (XXIV), which occur in the cardiac glycosides, may arise from the methyl hemi-acetals of 4-desoxytetroses (XXIII) and acetaldehyde. l o 6 2. Glilcal Method The best known and probably still the most direct'method for the synthesis of 2-desoxysugars is the Fischer glycal m e t h ~ d . a ~ The '~~ (105) L.Hough and J. K. N. Jones, Nature, 167, 180 (1951). (106) W.G. Overend and M. Stacey, J . Sci. Food Agric., 1, 168 (1950). (107)E.Racker, (a) Nature, 161, 408 (1951);(b) J . Bio2. Chem., 196, 347 (1952). (108)Quoted by S. P. Colowick and N. 0. Kaplan, Ann. Rev. Biochem., 20, 526 (1951). (109) E.Fischer, Ber., 47, 196 (1914).
W. Q. OVEREND AND M. STACEY
HoHP OH3
OH3
zH9
Ho'H? OH3
H0H;7 OH3'H3 HoH? *OH?
68
+
OH3
t
IH?
IIoH? 6H?
IIXX
IXX 'H30HT Z H HOH? ; Y3\ O'H3 OH3
zH9
HoHP HOH?
hIXX
HO
sHf HoHP
IIIXX
essential stages involve conversion of an acetyIated aldose (XXV) into a 1-bromoaldose acetate (XXVI) which is reduced by zinc dust and acetic acid and subsequently deacetylated to give the glycal (XXVII).logs To obtain the desoxysugar (XXVIII) the elements of water are added to the olefinic linkage in the glycal by treatment with dilute sulfuric acid at low temperature. The method has been widely used for many
I
HCOAc
A
xxv
1
Hbtlr
0
o + HCOAc I
I
I
XXVI
XXVII
XXVIII
years, and the following desoxysugars have been obtained from the ,~~.~~~.~~~ appropriate glycal : 2-desoxy-w110-114 and - ~ - r i b o s e , ~ ~2-desoxy(10Qa) Glycals and their reactions are reviewed by B. Helferich, Advances in Carbohydrate Chem., 7, 209 (1952). (110) G . 13. Feiton and W. Freudenberg, J . Am. Chem. SOC.,67, 1637 (1935). (111) A. M. Gakhokidze, Zhur. ObshcheZ Khim., 16, 539 (1945). (I 12) R. E. Deriaz, W. G. Overend, M. Stacey, Ethel G. Teece and L. F. Wiggins, J . Chem. SOC.,1879 (1949). (113) K. Ohta, J . Biochem. Japan, 38, 31 (1951). (114) K. Ohtn and K.Mnkino, Science, 113, 273 (1951). (115) M. Gehrke and F. X. Aichner, Ber., 60, 918 (1927).
CHEMISTRY OF THE 8-DESOXYSUQARS
69
D-xylose,30-60v116 2 - d e s o x y - ~ - g ~ u c o s e ,3-methyl-2-desoxy-~-glu~~~~~~~~~~-~~~~ cose, 122 3,4,6-trimet hyl-2-desoxy-n-glucose1lZ8 Zdesoxy-~-galactose,124-128 2-desoxy-~-fucose,~~~ 2 - d e s o x y - ~ - r h a m n o sand e ~ ~its ~ ~3-methyl ~~~ ether, 132 3-methyl-2-desoxy-~-chinovose,~~~ 2-desoxy-~-cellobiose~~~~~~~ and its and 2-desoxy-~-gulomethy1hexaacetate,1362-desoxy-~-allomethylose~~~ 0 ~ 8 The . ~ method ~ ~ proved to be unsatisfactory for the preparation of 3-methyl-2-desoxy-~-allomethylose. 139 It is possible to replace the sulfuric acid used in this procedure by trifluoroacetic acid. 128 The glycal transformation has also been carried out in oivo. D-Glucal was was given per as to rabbits and from the urine 2-desoxy-~-g~ucose isolated as the p-nitrophenylhydraaone in an amount corresponding to 3 percent of the original glucal. By feeding 2-desoxy-~-glucoseit was possible to recover 7 percent from the urine.140 If the glycal is treated with a 2-3 percent solution of hydrogen chloride in methanol instead of with diIute aqueous acid, then the methyl glycoside of the 2-desoxysugar is obtained. In this way L-arabinal was converted into methyl 2-desoxy-fl-~-ribopyranoside,1 4 1 D-glucal into methyl (116) A. RI. Gakhokidze, zhur. Obshchei Khim., 16, 530 (1945). (117) M. Bergmann and H. Schotte, Ber., 64, 440 (1921). (118) M. Bergmann, H. Schotte and W. Lechinsky, Ber., 66, 1052 (1923). (119) D. Barnard and F. Challenger, J . Chem. Sor., 110 (1949). (120) W. G. Overend, M. Stacey and J. Stangk, J. Chem. Soc., 2841 (1949). (121) S. G. Laland, W. G. Overend and M. Stacey, J. Chem. Soc., 738 (1950). (121a) F. B. Cramer, J . Franklin Znst., 263, 277 (1952). (122) €I. R. Bolliger and D. A. Prins, Helv. Chim. Acfa, 29, 1121 (1946). (123) 14:. L. Hirst and C. S. Woolvin, J . Cheni. SOC.,1131 (1931). (124) P. A. Levene and R. S. Tipson, 1.Rtol. Chem., 98, 644 (1931). (125) 11. S. Isbell and W. W. Pigman, J . Research Natl. Bur. Standards, 22, 397 (1939). (126) C. Tamm and T. Reichstein, Helv. Chrnt. Actu, 31, 1630 (1948). (127) W. G. Overend, F. Shafizadeh and X I . Stacey, J. Chem. SOC.,671 (1950); 992 (1951). (128) A. B. Foster, W. G. Overend and hZ. Stacey, J . Chem. Soc., 974 (1951). (129) €3. Iselin and T. Reichstein, Helv. China. A d a , 27, 1200 (1944). (130) B. Iselin and T. Reichstein, Helu. C h m . Bcfo, 27, 1146 (1944). (131) M. Bergmann and S. Ludewig, Ann., 434, 105 (1923). (132) F. Blindenbacher and T. Reichstein, Helu. Chzm. Acta, 31, 2061 (1948). (133) E. Vischer and T. Reichstein, Helu. Chim. A d a , 27, 1332 (1944). (134) M. Bergmann and W. Breuers, Ann., 470, 38 (1929). (135) A. M. Gakhokidse, Zhur. Obshcheg Khim., 16, 1914 (1946). (136) W. N. Haworth, E. 1., Hirst, H. R. L. Streight, 13. A. Thomas and J. I. Webb, J . Chern. Soc., 2636 (1930). (137) B. Iselin and T. Reichstein, Helv. Chinz. A d a , 27, 1203 (1944). (138) A. S. Meyer and T. Reichstein, Helv. Chim. Acta, 29, 139 (1946). (139) C. A. Grob and D. A. Prins, Helv. Chim. Ada, 28, 840 (1945). (140) M. Kondo, Biochem. Z., 160, 337 (1924). (141) R . E. Deriaz, W. G. Overend, M. Stawy and L. F. Wiggins, J . Chem. SOC., 2836 (1949).
70
W. 0. OVEREND AND M. STACEY
2-desoxy-a-~-glucopyranoside~~~~~~ and D-gslactal into methyl 2-desoxycr-~-galactopyranoside.~~~.~~~ By the use of ethanolic hydrogen chloride, Dgalactal was converted also into ethyl 2-desoxy-cr/3-~-galactopyranoside. 12* The reactions involved in the glycal synthesis have been studied in considerable detail, especially in the conversion of arabinose into 2-desoxyribose. For this particular conversion the overall yield has been doubled by recently introduced improvements but it is still very low.11a The reduction of the acetobromoaldose to the acetylated glycal by zinc dust and acetic acid was found to proceed in better yield if a few drops of chloroplatinic acid were added at intervals to maintain a vigorous reaction.112g120-127 Moreover, the reaction could then be conducted at lower temperatures (i. e., -5” to - 10’). This was particularly the case in the pentose series, and the simultaneous formation of the pentose tetraacetate by replacement of the bromo group by an acetyl residue, was much reduced.60a112 Hughes14* demonstrated that the maximum yield of triacetylglucal from acetobromoglucose was obtained when the addition of zinc dust and catalytic amounts of chloroplatinic acid was spread over several hours and the reaction mixture was maintained at 0”. A modification of Fischer’s method dispenses with the isolation of the acetobromoaldose and permits the isolation of the acetylated glycal in improved yield. 130 For the conversion of arabinose into diacetylarabinal, however, Deriaz and coworkers112claim that it is preferable to isolate both tetraacetyl-a-arabinose and acetobromoarabinose in crystalline form, if maximum yields are desired. Deacetylation of the glycal was effected smoothly by the ZemplBn-Pacsu meth0d,’~4 a procedure which was much more convenient than that employed originally by Bergmann and S ~ h o t t e , who ~ ~ ?used methanol saturated a t 0’ with gaseous ammonia. From a survey of the results of various investigators, P r i n P concluded that the yields of glycal obtained vary apparently according to the structure of the aldose used, thereby pointing to steric effects exerting an influence on the course of the reaction. He forwarded a mechanism which might conceivably explain the formation of a glycal from an acetobromoaldose. 146 (142) W.J. M.Philpott, M. Sc. Thesis, University of Birmingham, 1951. (143) I. W.Hughes, Ph. D. Thesis, University of Birmingham, 1949. (144) G.Z e m p l h and E. Pacsu, Ber., 62, 1613 (1929). (145) D.A. Prins, HeZu. Chim. Acta, 29, 1 (1946). (146) This mechanism was suggested by D. A. Prins and discussed by B. Iselin in “Synthese der 1-Rhamnodesose, 1-Fucodeaose 7~ndD-Digitoxme,” Doctoral Thesis, Univ. of Basel, 1944. See also D.A. Prins and R. W. Jeanloz, Ann. Reu. Biochern., 17, 67 (1948).
71
CHEMISTRY O F THE 2-DESOXYSUGARS
Ionization of acetobromoaldose (XXIX) furnishes the cation (XXX) which may subsequerit,ly yield either the neutral compound (XXXI) or the anion (XXXII). I n the former case, simple substitution a t carbon atom 1 occurs. The extent of t>hisreaction will depend on the relative rates of the reaction velocities X X X X X X I and X X X + X X X I I . Steric hindrance from the substituent 0 1 1 carbon atom 2 will favor the latter change. During the change X X X 3 XXXI, Walden inversion may occur. If the cation X X X is transformed to the anion XXXII, two further reactions may occur, probably simultaneously. The negative charge or1 carbon atom 1 in X X X I I gives rise to an electronic displacement, resulting in the ejection of an aretate ion from carbon atom 2 and formation of the glycal XXXIV. Alternatively, a proton may satisfy
-
H
I
C
m 0
-
-
ljrs
I
HCoAc I
H'!q I
-
HCoAc I
H
+BQ
0
I
R
xxx
XXIX
I
I
C
n
0
- H7°Ac I
-OH or -0Ac XXXI
2 Electrons from metal
c I
n
0
H7°Ac I XXXIII
+ €I@
H
v c
HC OAc
I
XXXII
I
-O
A
~
~H
11
HC
I
C
7 I
XXXIV
the negative ion in XXXII, resulting in the formation of an alditol anhydride (XXXIII). Here also the relative ratio of the velocities of the conversions X X X I I X X X I I I and X X X I I + XXXIV will influence the course of the reaction; even more predominantly so, since steric eflects which would operate in the change X X X I I + XXXIII should exert only a minor influence due to the smallness of the entering proton. Theoretically also the interaction of X X X and X X X I I t o form a dimer is conceivable. That carbon atom 2 must carry an ionizable substituent if a glycal is to be formed, is substantiated by the fact that 2-methyl-aldoses do not furnish glycals. 147 The varying steric effects mentioned might furnish an explanation for the varying yields obtained from different aldoses. So far compounds of the anhydroalditol type (XXXIII) seem to have escaped detection. (147) H. R. Bolliger and D. A. Prins, unpublished data, quoted by R. W. Jeanloz and D. A. Prins, Ann. Rev. Biochem., 17, 67 (1948).
72
W. 0. OVEREND AND M. STACEY
It was assumed by Isbell and PigmanlZ5that on treatment of D-galactal with dilute sulfuric acid the desoxysugar was formed via an intermediate ester which was hydrolyzed when heated with barium carbonate found that a t 60” for a relatively long period. Overend and the desoxysugar could be obtained in improved yield by introducing a rapid neutralization of the reaction mixture with barium hydroxide at room temperature. Moreover, potentiometric titrations (with N potassium carbonate) of 5 percent aqueous sulfuric acid containing D-galactal or D-glUCal did not materially differ from those of 5 percent aqueous sulfuric acid alone, thereby indicating that the acid concentration was not decreased by entering into stable ester formation with the glycal. Polarimetric observation of a solution of D-galactal in dilute sulfuric acid indicated that the reaction yielded directly 2-desoxy-~-galactose,since the final value of the optical rotation of the solution was the same as that of the desoxysugar in similar sulfuric acid solution. Whether an unstable transient ester is formed is not known, but it would appear that the process described by Isbell and PigmanlZ6as intermediate ester hydrolysis by barium carbonate, was merely slow heterogeneous-phase neutralization of the sulfuric acid. Cramer121aconsiders it likely that a probable mechanism would be the proton-catalyzed opening of the oxygen bridge of the glycal, resulting in a vinyl-alcohol structure which would immediately rearrange to the aldehyde form. 2-Desoxysugars may also be obtained by the addition of hydrogen bromide to glycals. Fischer, Bergmann and Schottea recorded that triacetyl-D-glucal and hydrogen bromide in acetic acid gave a crystalline “ diacetyl-D-glucal hydrobromide ” which on reacetylation yielded “ triacetyl-D-glucal hydrobromide.” The bromine atoms in these compounds were stated to be inert towards silver nitrate, a behavior which supported Fischer’s view that these were 2-bromo-2-desoxysugar derivatives. This opinion seemed to be difficult to accept since in the above described “glycal procedure” on the addition of water to glycals in the presence of dilute sulfuric acid, the opposite type of orientation is obtained, the anion becoming attached to carbon atom 1. Repetition of this work by Davoll and L y t h g ~ e yielded ’ ~ ~ a sirup which behaved as 3,4,6-triacetyl-l-bromo-2-desoxy-~-glucose, since on condensation with theophylline silver, followed by deacetylation, they obtained 2’-desoxyD-glucopyranosyltheophylline, identical with that first prepared by Levene and Cortese. 150 Consequently it was concluded that additions to glycals and acetylated glycals follow identical courses. A similar (148) W. G . Overend, F. Shafizadeh and M. Stacey, J . Chem. Soc., 992 (1951). (149) J. Davoll and B. Lythgoe, J . Chem. Soc., 2526 (1949). (150) P. A. Levene and F. Cortese, J. Biol. Chem., Q2,53 (1931).
CHEMISTRY OF THE 2-DESOXYSUGARS
73
conclusion had been earlier reported by Stacey and his colleagues, 1 4 8 , 1 5 1 who showed that both n-galactal and triacetyl-D-galactal reacted in the same way with methanol containing 2 percent hydrogen chloride, affording respectively methyl 2-desoxy-~-galactopyranoside and its triacetate. However, in neither case was the reaction simple, since the glycosidic product was accompanied by furfural derivatives.162 3. Pischrr and XowtJeii Method
Another route to 2-desoxysugars has been described by Fischer and Sowden and is based on an early discovery by Schmidt and Rutz.lss These latter workers demonstrated th at treatment of a-acetoxy primary nitroparaffins in ethereal solution with potassium hydrogen carbonate results in their ready loss of one molecule of acetic acid to give rise to the corresponding primary nitro-olefins. Fischer and S ~ w d e nshowed '~~ that condensation of a n aldose with nitromethane yields a mixture of epimeric C-nitro-alcohols, and subsequently showed th a t these on acetyIat,ion and treatment with bicarbonate in nonpolar solvent give rise t o a n acetylated nitro-olefin. Partial hydrogenation of this affords the l-nitro-1,2-didesoxy-derivative,the acid-sodium salt of which is hydrolyzed t o a 2-desoxysugar by sulfuric acid.155 The method was used successfully initially for the preparation of 2-desoxy-~-ghcose.~D-Arabinose was treated with nitromethane in the presence of sodium methoxide and gave a mixture of I-nitro-1-desoxy-nmannitol (XXXV) and 1-nitro-1-desoxy-D-glucitol (XXXVI). The mixture was not separated, but was acetylated and subsequently treated with bicarbonate to convert it into ~-arabo-3,~,5,6-tetraacetoxy-l-nitro1-hexene (XXXVII). Reduction of XXXVII with hydrogen in the presence of a palladium catalyst yielded l-nitro-3,4,5,6-tetraacetyl 1,2-didesoxy-~-glucitol(XXXVIII) which on treatment with sulfuric acid readily afforded 2-desoxy-~-glucose (XXXIX). The desoxyhexose was isolated as the benzylphenylhydrazone and the free sugar was obtained by cleavage of the hydrazone residue with benzaldehyde."' A mixture of isomers was obtained, with the a-form predominating. Essentially similar results have been described by Stacey and coworkerslZ0who were able to isolate directly crystalline 2-desoxy-~-glucose, without first forming t,he benzylphenylhydraxone. (151) For an account of this work see Chemistry & Industry, 466 (1949). (152) F. Shafizadeh and M. Stacey, J. Chem. SOC.,3608 (1952). (153) E. Schmidt and G. Rutz, Ber., 61, 2142 (1928). (154) 1-1. 0. L. Fischer and J. C. Sowden, J . Am. Chent. SOC.,66, 1312 (1944); 67, 1713 (1045); 68, 1511 (1946); 69, 1963 (1947). (155) J. C. Sowden, I J . S. Pat. 2,530,342 (1950).
74
W. G. OVEREND AND M. STACEY
CHzNOz
A
HO H H o AH
CHzNOz HAOH H d H
Ai'.
CHNOz
iH
AcO H
CHzN02
AcO H
CHO
I
CH2 H o AH
HboH
H h H
HhAc
HAOAc
HAOH
HAOH
H h H
HhAc
HLOAC
H OH
AH20H
xxxv
&H20H
XXXVI
AHzOAc
XXXVII
I
CHzOAc
XXXVTII
t:I
CHzOH XXXIX
Recently D-arabinose was combined with nitromethane which had been and so rendered radioactive by the incorporation of the C14 isot0pe,~6~ there is a possibility of preparing radioactive 2-desoxy-~-glucose. 2-Desoxy-~-ribosehas been prepared by this method, using D-erythrose or derivatives thereof as the initial material. 167.168 Sowdenls7 used both 2,4-benzylidene-~-erythrose and D-erythrose as initial materials. The former compound was obtained from 4,6-benzylidene-~glucose16gby reducing it to 4,G-benzylidene-~-glucitol and then oxidizing the hexitol derivative with sodium metaperiodate. Hydrolysis of the benzylidene-n-erythrose readily gives the unsubstituted tetrose. Since 4,6-benzylidene-~-glucose is obtained only in low and uncertain yields by the method of Z e r ~ a s , Hockett '~~ and his colleagues160recommend as preferable the conversion of 4,6-ethylidene-~-glucose t o D-erythrose by this method. Treatment of 2,4-benzylidene-~-erythrose with nitro-methane and sodium methoxide gave a mixture of 3,5-benzylidene-l-nitro-l-desoxyD-ribitol and -D-arabitol, which was separated by virtue of a remarkable difference in the solubility of the isomers in chloroform. Hydrolysis and acetylation of the arabitol derivative resulted in the which was formation of 1-nitro-2,3,4,5-tetraacetyl-l-desoxy-~-arab~tol, converted into D-erythro-triacetoxy-1-nitro-1-penteneby boiling under reflux in benzene solution with sodium bicarbonate. Similarly, this compound could be prepared from D-erythrose. Reduction of the pentene derivative, followed by treatment with sulfuric acid, yielded 2-desoxy-~-ribose. S ~ w d e n ' purified ~~ the product by forming the benzylphenylhydrazone and regenerating the desoxypentose by treating with either benzaldehydes7 or formaldehyde.161 Overend and coworkers168favored formation of the anilide of the 1673168
' (156) J. C. Sowden, J . Bid. Chem., 180, 55 (1949). (157)J. C. Sowden, J . Am. Chem. Soc., 71, 1897 (1949);72, 808 (1950). (158) W.G.Overend, M. Stacey and L. F. Wiggins, J . Chem. SOC.,1358 (1949). (159)L. Zervas, Ber., 64, 2289 (1931). (160) R. C. Hockett, D. V. Collins and A. Scattergood, Abstracts Papers Am. Chem. SOC.,113, 2Q (1948). (161) 0.Ruff and G. Ollendorff, Ber., 32, 3234 (1899).
CHEMISTRY OF T H E
75
2-DESOXYSUGARS
desoxypentose as a means of isolation and purification. De-anilination was effected by treatment with 0.5 percent oxalic acid in aqueous solution, and 2-desoxy-~-ribosewas obtained in highly crystalline form. Good yields are obtained at all stages of this synthesis of 2-desoxyD-ribose, and for preparative purposes S ~ w d e nclaims ' ~ ~ that the isolation of intermediates is unnecessary. The method would be a valuable one for the preparation of 2-desoxy-~-ribose if D-erythrose were obtainable ~~ in a pure state in large quantities. Overend and c o ~ o r k e r s 'have investigated various methods for the preparation in bulk of this tetrose from easily accessible materials, but a completely satisfactory method is still required. 4. From d,S-Anhydro Sugars
A number of methods available for the synthesis of 2- and 3-desoxysugars depend upon the cleavage by various reagents of a 2,3-anhydro ring in alkyl aldosides. An anhydro ring of this type can theoretically cleave in two ways, giving rise to two different products, e. g.,
\I
I/
c-c
\ /
0
/AA"
\I
\'&&-
c-c
I/
\LA,! x-
-
I (!--\I
X
OH I
I
x
c-c.I /
The product that is obtained experimentally depends upon the structure of the molecule containing the ethylene oxide ring. By using appropriate reagents for the cleavage, however, it is possible to obtain either 2- or 3-substituted derivatives which can be converted directly to 2or 3-desoxysugar derivatives. The protection afforded by the glycosidic residue increases the possibility of improved overall yields of the desoxysugars. From a study of the action of sodium alkylmercaptides on methyl 2,3anhydrohexosides, Reichstein and his colleagues were able t o develop a new method for the preparation of desoxysugars. When methyl 2,3-anhydro-4,6-benzylidene-cr-~alloside(XL) was heated under reflux with sodium methylmercaptide in methanol solution, cleavage of the anhydro ring occurred, and after purification by chromatographic procedures, methyl 4,6-beneylidene-2-methylthio-2-desoxy-c~-~-altroside (XLI) was obtained. Hydrogenation of this in the presence of Raney nickel readily converted it into methyl 2-desoxy-a-~-nlloside(XLII) .1623168
(162) R. Jeanloz, D. A. Prins and T. Reichstein, Experienliu, 1, 336 (1845). (163) R. Jeanloz, D. A. Prins and T. Reichstein, H e b . Chin&.Actu, 29, 371 (1946).
76
W. 0. OVEREND AND M. STAGEY
If a large excess of nickel is used for the reductive desulfurization, the 4,6-benzylidene substituent is also split off, whereas if less nickel is employed this substituent is retained. Sodium ethylmercaptide can be used equally successfully for the cleavage of the anhydro ring and the HCOCH3
HCOCHa
I
HCOCHs CHa8L€I HAOCH,
.
I
HCO
HCO
I
I
HCO-
/
CH20
XLI
w b 5
CH-CaHs
h,OH XLII
A&O/
XL
\\
CHO CONHz
HCOCHs
AH*
HCOH 1
HA011
H &OCII,
HA0
HboH
CONHz
&H,OH XLIV
~HzOH XLV
I
I
XLVI
resultant methyl 4,6-benzylidene-2-ethylthio-2-desoxy-cr-~-altrosid~ can readily be converted by simultaneous reductive desulfurization and debensylidenation into methyl 2-desoxy-a-~-alloside (XLII) by Bougault, Cattelain and Chabrier’s procedure. 165 That the desoxyglycoside (XLII) had been correctly designated as a 2-desoxysugar derivative was proved by the following sequence of reactions. Methylation of the product of ring scission, with silver oxide and methyl iodide, afforded a methyl henzylidene-monomethyl-methylthio-2-desoxy-cr-Dhexoside (XLIII), which was converted into a methyl monomethyl-2desoxy-a-D-hexoside (XLIV) by simultaneous debenzylidenation and reductive desulfuriEation. Hydrolysis afforded a monomethyl-2-desoxyhexose which on oxidation with potassium permanganate gave L#-(-)methoxysuccinic acid which was isolated as the diamide (XLVI). The isolation of this isomer of methoxysuccinic acid proves conclusively that the methylthio substituent in the product of ring cleavage (i. e., in XLI) (164)F.H. Newth, G. N. Richards and 1., F. Wiggins, J . Chem. Soc., 2356 (1950). (166) J. Bougault, E. Cattelain and P. Chabrier, BulZ. 80c. chim., 7, 781 (1940).
77
CHEMISTRY OF THE 2-DESOXYSUGARS
had been correctly assigned to carbon atom 2. If in the initial reaction the substituent had entered a t position 3, then D ~ - (+)-methoxysuccinic acid would have been obtained from this sequence of reactions. It follows that XLIII is methyl 4,6-benzylidene-3-methyl-2-desoxy-2-methylthio-a-D-altroside, XLIV is methyl 3-methyl-2-desoxy-a-~-alloside and XI,V is 3-methyl-2-desoxy-~-allose. Similar treatment of methyl 2,3-anhydro-4,6-benzylidene-1~-~-guloside166*'67(XLVII) with sodium methylmercaptide gave methyl 4,6benzylidene-2-methylthio-2-desoxy-a-~-idoside (XLVIII), which could
01'H CeH,-CH
/' \
I
HCO-
\I
OCH?
XLVII
XLIX
CHO
-8"
H OH
--I
HCOCII 3
I
O/TH 'CH HA0
1
\\
HCO-CH-CeHs
&&OH
L
readily be converted into methyl 2-desoxy-a-~-guloside~~*~~~~ (XLIX). That the desoxy-group was correctly located a t carbon atom 2 in XLIX wm proved by preparing the 4,6-benzylidene derivative and then methylating it. Hydrolysis of the product yielded a monomethyl 2-desoxyhexose (L) which on oxidation with potassium permanganate gave L~-(-)-methoxysuccinic acid, indicating that the desoxy group must be located at carbon atom 2 in L,which consequently is 3-methyl2-desoxy-~-gulose. (166) (16i) (168) (169)
E. Sorkin and T. Reichstein, Helv Chim. Ada, 28, 1 (1945). M. Gyr and T. Reichstein, Helu. Chim Acta, 28, 226 (1945). A. C. Maehly and T. Reichstein, He2v. Chim. Acta, 30, 496 (1947). H. Hauenstein and T. Reichstein, Helu. C h i m Ada, 82, 22 (1949).
78
W. G. OVEREND AND M. STACEY
With methyl 2,3-anhydro-4,6-benzylidene-a-~-mannoside (LI), cleavage of the anhydro ring by this method results in the formation of methyl 4,6-benzylidene-3-methylthio-3-desoxy-ru-~-altroside (LII) in practically quantitative yield. Reductive desulfurization gave methyl 4,6-benzylidene-3-desoxy-ru-~-altroside (LIII) l'o,lT1 since under the conditions used only slight " debenzylidenation " occurred. -I
CH30&
I
A
CsH6-CH-O , H
I' I
/
CHIO
LII
LIII
IJV
r--
CHaOCH
1:I
TI0 I I HCSMc
I
OCH CRHs-CH
//
I
HCO - -
\
\ OCH? I
LV
I
//
CEHS-CH \
HCO I
-\I
OCH2
LVI
Likewise, from treatment of methyl 2,3-anhydro-4,G-benzylideneP-D-taloside (LIV) it was shown that the products, which were obtained in excellent yield, were methyl 4,6-benzylidene-3-methylthio-3-desoxy0-D-idoside (LV) and then methyl 4,6-benzylidene-3-desoxy-P-~-idoside (LVI).172 The allocation of the desoxy-group t o position 3 is based on the same scheme of reasoning as previously described. From these experiments it appears that the splitting of the ethylene oxide ring of methyl 2,3-anhydro-4,6-benzylidene-hexosidesoccurs in the same way both with sodium methoxide and sodium thiomethoxide (sodium methylmercaptide) and reaction occurs according to the follow(170) H. R. Bolliger and D. A. Prins, Helv. Chim. Ada, 29, 1061 (1946). (171) D. A. Prins, J . Am. Chem. Soc., 70, 3955 (1948). (172) M. Gut, D. A. Prins and T. Reiohstein, Helv. Chim. Acta, 90, 743 (1947).
79
CHEMISTRY O F THE 2-DESOXYSUGARS
ing rule: in the D-series the thiomethyl or methoxyl group enters the Zposition when the ethylene oxide ring is pictured as to the right in the Fischer projection formula, and enters the 3-position when t o the left; while for the L-series, the thiomethyl or methoxyl group enters a t position 2 if the anhydro-ring is represented to the left and a t position 3 if represented to the right. Hence, by using a methyl 2,3-anhydro-hexoside of known configuration it is possible to predict which methyl desoxyhexoside will be formed on carrying out the reactions described above. The rule cannot be extended to include the cleavage of 2,3-anhydropentosides with sodium methylmercaptide, and attempts to convert 2,3-anhydropentosides to 2-desoxypentopyranosidesby t,his method have met with very limited success. In those cases where substitution was expected t o ocwr at carbon atom 2, the nucleophilic portion of the reagent molecule entered predominantly at position 3, giving derivatives from which 3-desoxypentopyranosides were obtained ; the reasons for this unfavorable orientation are not known. Methyl 2,3-anhydro-p-~-ribopyranoside(LVII) was caused to react with sodium methylmercaptide and thereafter the product was boiled under reflux with Raney nickel. The main desoxypentoside obtained was methyl 3-desoxy-P-~-riboside (LVIII) and only traces of methyl 2-desoxy-p-~-riboside were d e t e ~ t e d . ~ That ~ J ~ ~the structure assigned to LVIII was correct was demonstrated by hydrolysis to the desoxy-&OCII,
I
‘CH
bI
HO H -0CHz LVII
JOCII,
HC) H
I I IIOCH I
IICI-I
-OCH2 LVIII
COOH
I I CHI I IIOCH I HOCH
CHzOH LIX
peritose and oxidation of this w--h bromine water. Since L-erythro-1 ,3,4trihydroxyvaleric acid (LIX) was obttained, the desoxy group in the desoxypentoside must be located at position 3. Change of configuration at the glycosidic center had no effect since similar results were obtained Likewise, change in with methyl 2,3-anhydro-a-~-ribopyranoside.~~~ the size of the lactol ring had no effect on the orientation of the substituents. 174 In attempts t o synthesize 2’-desoxyribonucleosides, Lythgoe and his colleague^^'^ investigated the reaction between 2’,3’-anhydro-5’trityl-7-~-~-~bofuranosyl-theophy~~~ne (LX) and sodium ethylmercaptide. (173) 5. Mukherjee and A. R.Todd, J . Chern. Soc., 969 (1947). (174) J. Davoll, B. Lythgoe and S.Trippett, J . Chern. Soc., 2230 (1951).
80
W. 0. OVEREND AND M. STACEY
3'-Ethylthio-5'-trityl-3'-desoxy-7-~-~-xylofuranosyl-theophy~l~ne (LXI) was formed in higher yield together with a very small amount (ca. 1 percent) of 2'-ethylthio-5'-trityl-2'-desoxy-7-~-~-arabinofuranosyl-theophylline. The latter compound was not isolated, but after isolation of LXI, the mother liquors were desulfuriaed and the amount of 2'-desoxyC~H~O~NI \ Hf:q
HC/
1
HC-0
I
CHzOC (CsHs)8 LX
C7H70zNd H!Oj \CH EtSCIl HCO-
I
CHzOC (C6Ha)3 LXI
'7
/C7H702N4
"
I
CHzOH LXII
H : B/C7H70zN4
H SEt HC
I
CHzOH LXIII
pentose present was estimated by the method of Sevag and coworker^.^^ By successive detritylation, acetylation, desulfuriaation and deacetylation of LXI, 3'-desoxy-7-~-~-ribofuranosyl-theophylline was obtained. The conclusion that evidence provided by a negative Dische test indicated that the desoxypentose component was in reality 3-desoxy-~-ribosewas substantiated by hydrolysis of the compound designated above as 3'-desoxy-7-~-~-ribofuranosyl-theophylline. Reduction of the desoxypentose so obtained yielded a desoxypentitol which was optically inactive. This would result only if the desoxy group was located a t position 3 in the desoxy-pentose component of the above-mentioned nucleoside. Since ring scission of 2',3'-anhydro- 7-a-~-lyxofuranosyl-theophylline (LXII) with sodium ethylmercaptide also resulted in the entering sub~ ~ e., an almost quantitative yield stituent taking up the 3 - p o ~ i t i o n ' (i. of 3'-ethylthio-3'-desoxy-7-c~-~-arabinofuranosyl-theophyl~ne(LXIII) was obtained) it is obvious that the rule enunciated to explain the behavior of 2,3-anhydrohexopyranosidesis not valid for the explanation of the mode of scission of 2,3-anhydropentofuranosides. The action of halogen acids on alkyl 2,3-anhydro-aldosides results in the formation of an alkyl 2-halogeno- or 3-halogeno-desoxyaldoside which can readily be reduced to give the corresponding alkyl 2- or 3-desoxyaldoside. The action of hydrochloric and hydrobromic acids on methyl 2,3anhydro-4,6-benzylidene-a-~-allosidewas studied by Newth, Overend and Wiggins.176 Each reagent was shown to produce two distinct methyl halogeno-desoxy-a-D-hexosides. Hydrobromic acid gave methyl 2-bromo-2-desoxy-a-~-altroside and methyl 3-bromo-3-desoxy-a-~-glu(175) F. H. Newth, W. G. Overend and L. F. Wiggins, J . Chem. Soc., 10 (1947).
81
CHEMISTRY O F THE 2-DESOXYSUGARS
coside. Hydrochloric acid furnished the corresponding 2-chloro- and 3-chloro-derivatives. I n each reaction the main product was the glucose derivative. Although in this case repeated attempts to convert the chloro-sugars into desoxysugars were unsuccessful, it was possible to convert the bromo derivatives into desoxysugars. Hydrogenation of methyl 4,6-benzylidene-3-bromo-2-methyl-3-desoxy-~-~-glucoside in the presence of Raney nickel as a catalyst, and with potassium hydroxide added to neutralize the hydrogen bromide formed in the reaction, was completed successfully, and it was possible to isolate methyl 4,6-benzylidene-2-methyl-3-desoxy-c~-~-allos~cle.~~~ The potassium hydroxide can C H , O L H
CH,O~II
I I
I
BrCH HCOH HAOH
LXIV
LXV
I -I CHaOCH CHaOCH
&HZ
I
HbOH
HCOH HLOH
I
CHzO-
LXVII
HLOH
I
CH2O
LXVIII
be replaced by barium carbonate, calcium hydroxide or diethylamine176-177 and reduction can be effected equally well with sodium amalgam.164.178 In attempts to develop a satisfactory method for the synthesis of 2-desoxy-~-ribose,Stacey and his colleagues179investigated the action of hydrobromic acid on methyl 2,3-anhydro-P-~-riboside (LXIV), The anhydro ring was cleaved with the formation mainly of methyl 3-bromo3-desoxy-p-~-xyloside(LXV) and of only a small amount (10 percent) of methyl 2-bromo-2-desoxy-~-~-arabiaoside (LXVI). Since the derivative of methyl xyloside crystallized with ease, whereas the derivative of (176) W. T. Haskins, R. M. Ilann and C . 8. Hudson, J. Ant. Chem. Soc., 68, 628 (1940). (177) E. Hardegger and R. M. Montavon, Helu. Chim. Ada, 29, 1199 (1946). (178) G. N. Richards, Ph.D. Thesis, University of Birmingham, 1951. (179) P. W. Kent, M.Stacey and L. F. Wiggins, Nature, 161, 21 (1948); J . Chem. Soc., 1232 (1949).
82
W. G. OVEREND AND M. GTACEY
methyl arabinoside remained liquid, these isomers were easily separated. Separation could also be secured by acetonation of the mixture, since only the arabinose isomer formed an isopropylidene derivative. An alternative and precise separation was achieved by chromatographic adsorption of the mixture on a column of alumina. The methyl 2-bromo2-desoxy-/I-n-arabinoside (LXVI) was more readily eluted from the column than was methyl 3-bromo-3-desoxy-~-~-xyloside(LXV). Catalytic hydrogenation of LXVI in the presence of Raney nickel and calcium hydroxide afforded methyl 2-desoxy-P-~-riboside (LXVII). This on hydrolysis with dilute acetic acid yielded 2-desoxy-~-ribose, which was isolated as the aniline 2-desoxy-~-riboside. Likewise dehalogenation of LXV gave methyl 3-desoxy-p-~-riboside (LXVIII). The position of the desoxy group in LXVIII was established by hydrolyzing it and hydrogenating the product. The resultant desoxypentitol and its tetrabenzoate were both optically inactive, indicating that the 3-desoxypentitol must be 3-desoxyribitol (LXIX). Allerton and Overendlsoshowed that the action of hydrochloric acid on LXIV leads to a slightly better yield (18.4%) of the methyl 2-halogeno2-desoxy-~-arabinoside, but these methods have no value for the large scale synthesis of 2-desoxy-~-ribose. Reactions between compounds of the ethylene oxide type and Grignard reagents have long been known, and a t first it was accepted that the normal reaction was that in which opening of the ring by RMgX occurred to yield compounds of the type R’-CHR-CHOH-R”. Thus Henryl*l found that propylene oxide and ethyl magnesium bromide yielded 2-pentanol. It soon became apparent, however, that certain reactions which initially were regarded as abnormal, were in fact quite common. These resolved themselves into two classes: (i) the formation of halogenohydrin derivatives, and (ii) rearrangement of the epoxy compound to a ketone or aldehyde which subsequently reacted with the reagent in the usual way. BlaiselE2first noted that ethylene oxide and ethylmagnesium bromide formed ethylene bromohydrin, and Grignardl** then showed that by conducting the reaction a t - 15’ and removing the solvent (ether) by distillation before hydrolysis, 1-butanol was obtained. More recently, Wiggins and Wood184have found that the action of methylmagnesium iodide on 1,2 :5,6-diepoxy-hexane leads to dihydroxy-l,6diiodohexanes, and that similar treatment of 3,4-isopropylidene-l,2 :5,6(180) (181) (182) (183) (184)
R. Allerton and W. G. Overend, J. C h m . SOL, 1480 (1951).
L. Henry, Compt. rend., 146, 453
(1907).
E. E. Blaiae, Compt. rend., 134, 551 (1902). V. Grignard, Bull. SOC. chim., [a], 89, 946 (1903). L. F. Wiggins and D. J. C. Wood, J. Ghem. SOC.,1566 (1950).
CHEMISTRY O F THE
2-DESOXYSUGARS
83
dianhydro-D-mannitol gives 3,4-isopropylidene-l,6-diiodo-l16-didesoxyD-mannitol. Similarly, 4,5-isopropylidene-l,2 :3,B-dianhydro-~-mannitol is converted into 4,5-isopropylidene-3,6-anhydro-l-iodo-l-desoxy-~-mannitol by treatment with methylmagnesium iodide.185 In fact it becomes increasingly likely that this type of reaction is the more common, and Wiggins and his coworkers'64 were prompted to investigate the reactions between alkylmagnesium iodides and anhydro sugars of the ethylene oxide type. The formation of iodinated sugar derivatives is valuable since compounds of this class can be readily convertible into desoxy sugars. I n 1948, PrinsI7l introduced another method for the direct reduction of sugar epoxides t o desoxysugars. Methyl 2,3-anhydro-4,6-benzylidenea-walloside was reduced with lithium aluminum hydride according to the general procedure of Nystrom and Brown.'s6 The product was methyl 4,6-benzylidene-2-desoxy-a-~-alloside. Likewise, treatment of methyl 2,3-anhydro-4,6-ditosyl-a-~-alloside with lithium aluminum Similar hydride afforded methyl 2-desoxy-4,6-ditosyl-a-~-alloside.~~~~ reduction of methyl 2,3-anhydro-4,6-benzylidene-a-~-guloside gave methyl 4,6-benzylidene-2-desoxy-a-~-guloside.'~~ However, if methyl 2 ,3-anh ydr 0-4 ,6-benzylidene-a-~-mannoside was used in this reaction) the desoxy group in the product was located at position 3 since methyl 4,6beneylidene-3-desoxy-a-~-altroside was obtained.'?' Consequently, it seems that reductive cleavage by lithium aluminum hydride of the anhydro ring in these derivatives follows the same course as the action of either sodium methoxide or thio-methoxide. Anomalous results are obtained with methyl 2,3-anhydro-pentosides, since reaction between lithium aluminum hydride and methyl 2,3-anhydro-p-~-riboside gave mainly methyl 3-desoxy-@-~-ribosideand only a small amount (14 percent) of methyl 2-desoxy-P-~-riboside, whereas according to prediction the 2-desoxy isomer would have been expected t o be formed predominantly. 5 . Other Methods
Several general synthetic routes for the preparation of 2-desoxy-Dribose have been described. H o ~ g h ' ~has ' outlined a novel method for the synthesis of 2-desoxyD-ribose. An excess of allylmagnesium bromide was allowed to react with 2,3-isopropylidene-~-glyceraldehyde~~~ in ethereal solution and, (185) A. B. Foster and W. G. Overend, J. Chem. Soc., 1132 (1951). (186) R. F. Nystrom and W. G. Brown, J. Am. Cheni. SOC.,69, 1197 (1947). (186a) H. R. Bolliger and M . Thiirkauf, Helv. Chzrn. A d a , 36, 1428 (1952). (187) L. IIough, Chemzslry tC Industry, 406 (1951). (188) E. Baer and H. 0. L. Fischer, J. Bzol. Cheni., 128, 463 (1939).
84
W. G. OVEREND AND M. STACEY
after decomposition of the resultant complex, sirupy 5,6-isopropylidenel-hexene-4,5,6-triol (LXX) was obtained in excellent yield. This reaction results in the formation of a new asymmetric center(*) a t carbon atom 4. Catalytic hydrogenation of LXX, followed by hydrolysis, resulted in the production of a crystalline 1,2,3-tridesoxyhexitol in high yield. Since in these conversions only one isomer was isolated, it seems
*~HOH I
LXX
that an asymmetric synthesis occurs. The substance LXX may possess either the erythro or the threo type of configuration, but since 2-desoxyD-ribose is obtainable from this synthesis it would appear that LXX and the tridesoxyhexitol largely contain the erythro isomer. On treatment of LXX with a solution of hydrogen peroxide in tertbutyl alcohol containing a little osmium tetroxide as catalyst, the double bond is hydroxylated and a new center of asymmetry is produced a t carbon atom 2. Chromatographic analysis on paper strips revealed that the product contained a t least four components, which were separated on a column of cellulose using 1-butanol:petroleum ether (40 :60 parts v/v) as the mobile phase. A fraction containing 5,6-isopropylidene-3desoxyhexitols was obtained. Oxidation of this fraction with sodium metaperiodate in a phosphate buffer destroyed the asymmetric center a t carbon atom 2 and gave a mixture of 4,5-isopropylidene-2-desoxypentoses. Hydrolysis of these with sulfuric acid liberated the free sugars, which were isolated in sirupy form. Chromatographic examination indicated that the major component of the product was 2-desoxy-~ribose and this was separated from a small quantity of another sugar (2-desoxy-~-xylose?) by heating with ethanolic aniline. Crystalline aniline 2-desoxy-~-riboside~~~ was obtained, from which the parent sugar was easily regenerated. Another method for the preparation of 2-desoxy-~-ribose, using 2,3-isopropylidene-~-glyceraldehyde as an initial material has been outlined briefly by Overend and Stacey. l o o The glyceraldehyde derivative was condensed with acetaldehyde in the presence of anhydrous potassium
CHEMISTRY O F THE
2-DESOXYSUGARS
85
carbonate and afforded a mixture of 4,5-isopropylidene-2-desoxy-~-xylose and 4,5-isopropylidene-2-desoxy-~-ribose. This mixture was not separated but was hydrolyzed with acid and gave 2-desoxy-~-ribose and 2-desoxy-~-xy~ose, which were separated by chromatographic means. For both of these syntheses 2,3-isopropylidene-~-glyceraldehydeis readily accessible as an initial material since it can be prepared by oxidation of 1,2 :5,6-diisopropylidene-~-mannitol with lead tetraacetate in solution in dry From the account already given of the methods employed for the preparation of desoxyhexose derivatives by the action of various reagents on 2,3-anhydro derivatives of methyl hexosides, it is apparent th a t 3-substituted derivat,ives and thence methyl 3-desoxy-hexosides frequently are obtained. These desoxyglycosides on hydrolysis and subsequent oxidation with bromine water readily afford 3-desoxyhexonic acids. Application of the Ruff and Ollendorf method161of descent of the sugar series to an acid of this type should lead directly to a 2-desoxypentose, and indeed, many years ago Kiliani and Loeffler5 succeeded in degrading 3-desoxy-~-gulonolactone t o 2-desoxy-~-xylose b y this method. Recently, derivatives of 3-desoxy-~-glucose have become a ~ a i l a b l e and , ~ ~ consequently ~~~~~ efforts have been directed towards the preparation of 2-desoxy-~-ribose from either calcium or barium 3-desoxy-~-ghconate. It has been shown in the writers’ laboratory that when the modificatioii of Ruff’s method that was introduced by Hockett and is employed, calcium 3-desoxy-D-gluconate can be degraded t o 2 - d e s o x y - ~ - r i b o s e . ~Recently, ~~~ Weygand and WOlziBgb prepared 2-desoxy-~-xylose by treating 3-desoxy-~-gu~ose(-galactose) oxime with 2,4-dinitrofluorobenzene, As the cleavage of 2,3-ethylene oxide rings in sugar derivatives leads to the production of isomers, various workers have sought to prepare by other methods sugar derivatives with substituents in the 2- or 3-position which could be converted easily into desoxy groups. When triacetylD-glucal is treated with bromine, for example in chloroformic solution, addition occurs a t the double bond and liquid lJ2-dibromo-3,4,6-triacetylhexose is formed. Treatment of t,his with methanol and silver carbonate readily effects glycosidation and two isomeric forms of methyl 3,4,6triacetyl-2-bromo-2-desoxyhexoside were obtained and separated. Each form readily underwent deacetylation. Either form of the resultant methyl 2-bromo-2-desoxy-~-hexoside on reduction with sodium amalgam gave methyl 2-desoxy-~-glucoside, from which 2-desoxy-~-glucose was (189) It. C. Hockett and C. S. Hudson, J. Am. Chem. SOC.,66, 1632 (1934). (189a) It. Allerton, W. H. Overend and M. Stacey, unpublished results. (189b) 1‘. Weygand arid H. Wolz, Ber., 86, 256 (1952).
W. 0. OVEREND AND M. STACEY
86
obtained by hydrolysis.3 This method has been used by Helferich and Iloff Ig0 to prepare phenyl 2-bromo-2-desoxy-a-~-glucoside and thence by reductive dehalogenation, phenyl 2-desoxy-a-~-glucoside. More recently, using this method the preparation of pyrimidine 2-desoxyglycosides has been reported.lg1 If 3,4,5,6-tetrabenzoyl-~-glucosediethyl mercaptal is treated with ethanethiol and hydrochloric acid, a thioethyl substituent enters the molecule a t carbon atom 2 and the product is 2-thioethyl-3,4,5,6-tetrabenzoyl-2-desoxy-D-hexose diethyl m e r ~ a p t a l ' ~ ~(LXXI). -'~~ This com-
1 " . rc2H5 h"? E"\
cH /SC2Hs
/OCH3
I
\SC& CHSCZHK
I
BzOCH
/OCHi
OCHI
OCHi
BaO H
HAOBz
HAOBz
..Ot."H OBz
HAOBa
H OBz
H OBz
c1
c1
I
CHzOBz
LXXI
/
CI H ~ O B Z
AH20Bz
IJXXII
LXXIII
OCHs
YH\
OCHI CHSC2Hb
I
IlOCH
CH
/OCH3
/
'OCH3 CHZ H oAH
HAOH
HAOH
HAOH
HAOH
AH2OH
AH20H
LXXIV
LXXV
pound is usually referred t o as a D-glucose derivative but it is not known whether Walden inversion occurs at carbon atom 2 during the reaction, so that it could equally well be a D-mannose derivative. (190) (191) (1949). (192) (193) (194) (195) (196)
B. Helferich and A . Iloff, Z . physiol. Chem., 221, 252 (1933). I. Goodman and J. P. Howard, Abstracts Papers A m . Chem. SOC.,116, 24C
P. Brigl and R. Schinle, Ber., 63, 2884 (1930). P. Brigl, H. Miihlschlegel and R. Schinle, Ber., 64, 2921 (1931). P. Brigl and R. Schinle, Ber., 66, 1890 (1932). H. R. Bolliger and M. D. Schmid, Helv. Chim. Acta, 34, 1597 (1951). H. R. Bolliger and M. D. Schmid, Helu. Chim. Acta, 34, 1671 (1951).
CHEMISTRY O F THE
2-DESOXYSUGARS
87
Bolliger and SchmidlgB" demercaptalated l 1 LXXI by the standard method of Wolfrom and coworkers1g7and obtained 3,1,S,6-tetrabenzoyl2-thioethy1-2-desoxy-hexose1 which was isolated as the dimethyl acetal (LXXII). Debenzoylation gave a crystalline 2-thioethyl-2-desoxyhexose dimethyl acetal (LXXIV) which was reductively desulfurized with nickel to afford 2-desoxy-~-glucose dimethyl acetal (LXXV).I98 Alternatively, LXXII could be reductively desulfurized to give 3,4,5,6tetrabenzoyl-2-desoxy-~-glucose dimethyl acetal (LXXIII), which could then be debenzoylated to yield LXXV, hydrolysis of which readily liberated 2-desoxy-~-glucose in good yield. (Another method for the introduction of a thiol residue into a sugar molecule was proposed by Freudenberg and Wolff. lg9) The replacement of toluene-p-sulfonyloxy a d methane-sulfonyloxy groups by iodine, using sodium iodide in acetone, has not been of great value in synthesizing 2-desoxysugars. Very recently however, Stacey and his colleagues'8gnsucceeded in directly replacing by hydrogen the toluene-p-sulfonyloxy group in methyl 2-toluene-p-sulfonyl-p-~-arahinoside. When either methyl 2-toluene-p-sulfonyl- or methyl 2-methanesulfonyl-3,4-isopropylidene-~-~-arabinoside was treated with lithium aluminum hydride, loss of the sulfonyl residue occurred and in both cases was obtained. When a similar methyl 3,4-isopropylidene-@-~-arabinoside reaction was carried out with methyl 2-toluene-p-sulfonyl- or methyl 2-methanesulfonyl-~-~-arabinoside, a complex mixture was obtained from which it was possible to isolate methyl p-L-arabinoside, methyl 2,3-anhydro-p-L-riboside, methyl 2-desoxy-p-~-riboside and methyl 3-desoxy-p-~riboside. During the reaction, loss of the toluene-p-sulfonyl residue is accompanied by anhydro ring formation yielding methyl 0-L-arabinoside and methyl 2,3-anhydro-p-~-riboside. The ethylene oxide ring in this latter compound is then apparently cleaved by excess lithium aluminum hydride with the formation of methyl 2 (and 3)-desoxy-p-~-riboside. If the formation of the anhydro ring is prevented, as is the case with either methyl 2-toluene-p-sulfonyl- or methyl 2-methanesulfonyl-3,4isopropylidene-p-L-arabinoside, then only removal of the toluene-psulfonyl group occurs and the sole product is methyl 3,4-isopropylidenep-L-arabinoside. Wolfrom and coworkersZn0applied the reaction of WolffZo1to acetyl(197) M. L. Wolfrom, L. J. Tanghe, R. W . George and S. W. Waisbrot, J . Am. Chem. Soc., 60, 132 (1938). (198) H. R. Bolliger, Helw. Chim. Acta, 34, 989 (1951). (199) K. Freudenberg and A. Wolff, Ber., 60, 233 (1927). (200) M. L. Wolfrom, S. W. Waisbrot and R. L. Brown, J . Am. Chem. Soc., 64, 1701 (1942). (201) L. Wolff, Ann., 394, 23 (1912).
W.
88
Q. OVEREND AND
M. STACEY
ated aldonic acids and succeeded in preparing from them, acetylated "aldodesonic" acids containing one additional carbon atom. Thus pentaacetyl-mgluconyl chloride (LXXVI) 202 was converted into l-diazo1-desoxy-lceto-n-ghcoheptulose pentaacetate (LXXVII) by treatment with diazomethane. Water and silver oxide in catalytic amount, transCOG1
HboAc
b
AGO H
HbOAc
HboAc bH*OAC
CHNi A0
bHz
HA0Ac
HbOAc HObH
AcObH WbOAc HAOAc kH20Ac
LXXVI
L
0
LXXVII
H&OAc bHzOAc
LXXVIII
HbOH bH,OII
LXXIX
formed this into tetraacetyl-2-desoxy-~-glucoheptonolactone (LXXVIII). Since the lactone was rapidly titrated to a stable end-point in 1.5 minutes from solution in aqueous acetone it must be a 6-laetone. De-acetylation of LXXVIII with barium hydroxide yielded 2-desoxy-~-glucoheptonolactone (LXXIX), designation of which as a t-lactone was based on Hudson's lactone rotation rule.
6. Sgnthesie of dl5-Didesoxysugars The most convenient method for the preparation of 2,3-didesoxysugars was introduced by Bergmann203s204 and depends upon the change undergone by glycals on warming them in water. When triacetyl-Dglucal (LXXX) is heated in water a t 100' for 15 minutes, an acetyl group is liberated and there is a simultaneous migration of the double bond, resulting in the formation of 4,6-diacetyl-2,3-didehydro-2,3-didesoxy-~glucose (LXXXI). Evidence adduced by Laland, Overend and Stacey206 indicates that the ethylenic linkage between carbon atoms 1 and 2 activates the acetyl substituent a t carbon atom 3 so that gentle heating with water is sufficient to eliminate it, and the acidity consequently developed induces migration of the double bond. Treatment of LXXXI with ethyl orthoformate in ethanol results in glycosidation and the (202) M. L. Wolfrom, D. I. Weisblat, W. H. Zophy and 5. W. Waisbrot, J . Am. Chern. Soc., 83, 201 (1941). (203) M. Bergmann, Ann., 443, 223 (1925). (204) M. Bergmann and W. Freudenberg, Ber., 64,168 (1931). (205) S. G . Laland, W. G. Overend and M. Stmey, J . Chem. Soc., 738 (1950).
CHEMISTRY O F THE
2-DESOXYSUGARS
89
production of ethyl 4,6-diacetyl-2,3-didehydro-2,3-didesoxy-~-allos~de (LXXXII). -I
HC
II IIC I
AcOCH
I
-I CHOH
I
HC
He
J
/
HC-
I HC I1 HC I
HCOAc
H OAc
HCOAc
H O-
a'co-
H O-
bI
CH~OAC LXXX
A
HCAH2
I
I
HCO -
CHzOAc I
bH2OAc
AI3,OH
LXXXI
LXXXII
LXXXIII
Since deacetylation of LXXXII and subsequent ozonization and treatment with water afforded glyoxal (isolated as the phenylosazone) it followed that the ethylenic linkage must be between carbon atoms 2 and 3.'04 Reduction of LXXXII, followed by deacetylation, yields ethyl 2,3-didesoxy-~-alloside (LXXXIII), Alternatively, LXXXI could be which on glycosidation converted into 4,6-diacetyl-2,3-didesoxy-~-allose, as above yielded ethyl 4,6diacetyl-2,3-~didesoxy-~-allo~de. I n this instance the product was a mixture of isomers, since on deacetylation, two forms (m. p. 72-72.5" and go", respectively) were isolated. Derivatives of 2,3-didesoxy-~-ribose~'have been prepared from 3,4-diacetylL-arabinal,
7. Synthesis of bDesozyhexomethyloses Which Occur in Cardiac Glycosides Using the various methods described for the preparation of 2-desoxysugars, Reichstein and his colleagues have synthesized the 2-desoxyhexomethyloses and 3-methyl-2-desoxyhexomethyloses which occur naturally as carbohydrate components of the cardiac glycosides. The present account refers briefly only to those researches reported since 1945 (see ref. 1). Digitoxose (2-~esoxy-D-at?lomethy~ose) and Cymarose (3-Methyl-2-desoxy D-allomethylose) .-Although digitoxose (2-desoxy-~-allomethylose~~~) had been prepared by Iselin and R e i c h ~ t e i nfrom ~ ~ ~ D-alIomethylose by the glycal method, Gut and Prins207devised another route for its synthesis. Methyl 2-desoxy-a-~-alloside was prepared from methyl 2,3-anhydro4,6-benzylidene-cr-~-alloside by the method devised by Reichstein and c o w o r k e r ~ 'and ~ ~ ~converted ~~~ into methyl 3,4-diacetyl-6-toluene-p(206) F. Micheel, Ber., 63, 347 (1930). (207) M.Gut and D. A. Prins, Helv. Chirn. Acta, 30, 1223 (1947).
90
W. G. OVEREND AND M. STACEY
sulfonyl-2-desoxy-~-~-alloside. The toluene-p-sulfonyloxy residue was exchanged for an iodo group by heating with sodium iodide and thereby was obtained. Demethyl 3,4-diacetyl-6-iodo-2,6-didesoxy-a-~-allos~de which halogenation afforded methyl 3,4-diacetyl-2,6-didesoxy-a-~-all0side on acidic hydrolysis gave 2-desoxy-~-allomethylose (digitoxose) . A synthesis of digitoxose has been described by Bolliger and U l r i ~ h . ~ " ~ ~ Cymarose, the 3-methyl ether of digitoxose,208was also prepared by PrinsZo9and by Bolliger and U l r i ~ h . ~ " ~ ~ D-Diginose (S-~%fethyl-2-desoxy-~-fucose) .-The synthesis of D-diginose was accomplished successfully by Tamm and Reichstein. 126 2-DesoxyD-galactose was prepared from D-galactose by the glycal method and converted into methyl 4,6-benzylidene-3-methyl-2-desoxy-a-~-gala~t0s~de by the established methods of carbohydrate chemistry. Debenzylidenation was achieved by heating at 80" in an atmosphere of hydrogen with Raney nickel. The product, methyl 3-methyl-2-desoxy-a-~-galactoside, was contaminated with some of the 4,6-hexahydrobenzylidene derivative. That the methoxyl group was correctly assigned a t carbon atom 3 was established by hydrolyzing the galactoside to a monomethyl-2-desoxyD-galactose which on oxidation with potassium permanganate yielded DS-( +)-methoxysuccinic acid (isolated as the diamide). This isomer of methoxysuccinic acid would only be obtained if in the monomethyl-2desoxyhexose the methoxyl group was adjacent to the desoxygroup, i. e., it must be 3-methyl-2-desoxy-~-galactose. Toluene-p-sulfonation of the galactoside afforded a mixture of methyl 6-toluene-p-sulfonyl- and methyl 4,6-ditoluene-p-sulfonyl-3-methyl-2-desoxy-~-~-galactoside. The former substance was readily converted into methyl 6-iodo-3-methyl-2,6didesoxy-a-D-galactoside, whereas the latter gave methyl 3-methyl-6iodo-4-toluene-p-sulfonyl-2,6-didesoxy-a-~-galactoside on treatment with sodium iodide in acetone. Both of these could be converted into methyl 3-methyl-2-desoxy-a-~-fucoside and thence into 3-methyl-2-desoxy-~fucose (D-dighose). Sarmentose (S-Methyl-2-desoxy-~-gulomethylose).-By employing a series of reactions similar t o those already outlined for the synthesis of diginose, Hauenstein and Reichsteinzl0 were able to convert methyl 3-methyl-2-desoxy-a-~-guloside into 3-methyl-2-desoxy-~-gulomethylose, which proved to be identical with natural sarmentose. L-Oleandrose (3-Methyl-d-desoxy-L-glucomethy1osel S-Methyl-2-desoxy-~rhamnose) .-3-Methyl-~-rhamnal was converted by Vischer and Reichstein133by use of the glycal method into 3-methyl-2-desoxy-~-rhamnose, (207a) H. R. Bolliger and P. Ulrich, Helv. Chim. Acta, 36, 93 (1952). (208) R. C. Elderfield, J . B i d . Chem., 111, 527 (1935). (209) D. A. Prins, Helv. Chim. Acta, 29, 378 (1946). (210) H. Kauenstein and T. Reichstein, Helv. Chim. Acta, 33, 446 (1950).
CHEMISTRY OF THE
2-DESOXYSUGARS
91
and it was apparent that this sugar was identical with Poleandrose. The natural product was shown to be L-oleandrose and its synthesis was ~ achieved at a later date by Blindenbacker and R e i ~ h s t e i n . ’ ~3-MethylL-rhamnose was converted by the glycal method into 3-methyl-2-desoxyL-rhamnose, and the product was identical with natural L-oleandrose from oleandrin. VI. TRANSFORMATION PRODUCTS 1. O-Glycosides
2-Desoxysugars are characterized by their ease of conversion to 0-glycosides. When 2-desoxy-~-glucose is treated for 15 minutes with
+80°
-
I1
0
20
40 Time, minutes
60
FIG.3.-Action of hlethanolic Hydrogen Chloride [0.03% (I), 0.3% (II), 3.0% (III)] on 2-Desoxy-~-ga~actose.
0.25-1.0 percent of hydrogen chloride in methanol, even at room temperature it forms methyl 2-desoxy-a-~-glucopyranoside.* Similarly, treatment of 2-desoxy-~-cellobiose with 1.O percent methanolic hydrogen chloride affords methyl a- and @-glycosidesof this sugar.ls4 The action of methanolic hydrogen chloride on a 2-desoxyhexose was first studied in detail by Stacey and his c ~ l l e a g n e swho , ~ ~ observed that treatment of 2-desoxy-~-glucose resulted in a series of characteristic changes in the optical rotation of the sugar. A similar series of changes was revealed when 2-desoxy-~-gahctose was placed in methanolic hydrogen chloride, but in this case the magnitude of the changes was much greater than was noted with 2-desoxy-n-glucose. 128 Figure 3 is indicative of the changes observed. For both desoxysugars, treatment with fairly low concentra-
92
W. Q. OVEREND AND M. STACEY
tions of hydrogen chloride in methanol results in a decrease in the optical rotation to a minimum value, followed by a subsequent increase in this rotation (Fig. 3, Curve 11). Termination of the reaction a t the minimum value of the optical rotation afforded the methyl (~/3-glycofuranosidesof the desoxysugars, whereas more extended treatment led to the formation of the methyl (Y- and P-glycopyranosides. With higher concentrations (i. e., 3 percent) of hydrogen chloride in methanol, the minimum value of the optical rotation was obtained instantaneously and was followed by a rapid increase to a final maximum value corresponding to the formation of the methyl glycopyranosides of the desoxysugars. A series of similar changes was observed on treatment of 2-desoxy-~galactose with ethanolic hydrogen chloride and it was possible t o prepare ethyl Z-desoxy-a/i?-D-galactofuranoside and ethyl 2-desoxy-a/i?-~-galactopyranoside. Essentially similar results were observed with desoxypentoses, and the methyl glyco-furanosides and -pyranosides of 2-desoxyL-ribose were prepared. 1 4 1 Other methods have been used to prepare O-glycosides of desoxysugars. Bergmann and his coworkers1ls converted tetrabenzoyl-2desoxy-D-glucose into l-bromo-tribenzoyl-2-desoxy-~-glucose by the standard procedure. This latter compound, when treated with methanol in the presence of silver carbonate, afforded after debenzoylation, methyl 2-desoxy-~-~-glucoside. The preparation of alkyl 2-desoxyglycosides from glycals has already been described, and the same products have also been obtained from desoxysugar mercaptals by the procedure of Pacsu and Green.l12r211 O-Glycosides of 3-desoxysugars can be obtained by the usual reactions of carbohydrate chemistry and the synthesis of glycosides of 2,3-didesoxysugars has already been discussed. Bergmann and his colleague^^^^^* obtained isomeric methyl 2-desoxywglucopyranosides of optical rotations -48.8' and 137.9"in water and described the latter as an a-form and the former as a p-form. These assignments were based on Hudson's system212that the more dextrorotatory anomer of a D- compound is termed a - ~ -the , other anomer being the @-D-forrn. Davoll and L y t h g ~ e lhave ~ ~ pointed out that these assignments would be unwarranted if they rested on the above rotational data alone, since it is not certain that the contribution of the asymmetric center at carbon atom 1 will be of the same sign in methyl 2-desoxyglycosides as in the related methyl glycosides. That this is true and that the configurational allotments are sound, is established by the circiim-
+
(211) E. Pacsu and J. W. Green, J . Am. Chem. Soe., 60, 1205 (1937); 60, 2056 (1938). (212) C. S. Hudson, J . Am. Chem. Soc., 81, 66 (1909).
CHEMISTRY O F THE
93
2-DESOXYSUGARS
stance that methyl 2-desoxy-@-~-glucopyranosidehas been connected configurationally with methyl 3,4,6-triacetyl-@-~-glucoside.~~~ Similarly, the product of glycosidation of 2-desoxy-~-ribose,designated by Stacey and his colleagues'41 as methyl 2-desoxy-p-~-ribopyranoxide was shown to be the optical enantiomorph of the compound obtained by Kent and coworkers17gfrom the catalytic hydrogenation of methyl 2-bromo-2desoxy-/?-D-arabinoside. For the latter compound there was no doubt of the @-D-configurationof the glycosidic component.
30 FIG. 4.-Isonierization
60 Time, minutes
90
120
of Methyl a- and /3-2-desoxy-~-galactopyranoaide by
2.5% HCI in Methanol.
The ap relationship between methyl 2-desoxyglycosides was studied by Stacey and his colleague^.'^^^^^^ They showed that one percent methanolic hydrogen chloride separately converts the a- and &isomers of methyl 2-desoxy-~-ribopyranoside into the a/?-mixture from which they were initially isolated. Similar results were obtained on treatment with two percent of hydrogen chloride in methanol of either the a- or p-forms of methyl 2-desoxy-~-galactopyranoside. Figure 4 illustrates the changes in the latter example. From Table I it will be seen that there is good agreement between the difference in the molecular rotations of the respective a- and @-formsof the methyl glycopyranosides of some sugars and their 2-desoxy-analogues. Until recently the configurations assigned to the alkyl glycosides of 2,3-didesoxysugars were based solely on Hudson's system. As the (213) E. W. Bodycote, W. N. Haworth and 13.1,. Hirat, J . Chem. Soc., 151 (1934).
94
W. G. OVEREND AND M. STAGEY
action of sodium carbonate on methyl 4,6- benzylidene-2-toluene-psulfonyl-3-desoxy-c-~-altrosideled t o the formation of methyl 4,fi-bensylidene-2,3-didehydro-2,3-didesoxy-a-~-alloside, and then, by reduction, 170 an alternative met,hod methyl 4,6-benzylidene-2,3-didesoxy-cu-~-alloside, TABLE I Molecular Rotations of Anomers of Methyl Glycopyranosides and of Methyl 2-Desoxyglycopyranosides Methyl glycopyranoside of L-Arabinose
lnomer +17.3 +245.5
2840 40,260
-37,420
214
-43.4 +202.3
- 6420 29,940
-36,360
141
+158.9 -31.97
30,830 -6200
+37,030
215, 216
f138 -48.2
+24,600
+33,100
3, 6
+178.8 -0.42
33,300 -80.5
+33,380
217-22 1
B a
+170
127
+O
30,300 0
+30,300
B
a
B 2-Desoxy-~-ribose (2-Desoxy-~-arabinose)
a
D-Glucose
a
B
s a
P u-Galactose !%Desoxy-D-galactose
References
[MI
a
-8500
was made available for checking the accuracy of configurations assigned to methyl glycosides of 2,3-didesoxysugars on the basis of Hudson's system, The lactol ring structures of the methyl glycosides of 2-desoxy-pentoses and -hexoses were established by the classical methods of carbohydrate chemistry. To illustrate the procedures adopted, investigations carried out with the methyl glycosides of 2-desoxy-~-ribose'~~ will be described, similar methods having been adopted to establish the structures of alkyl glycosides of other 2-desoxysugars. (214) (215) (216) (217) (218) (219) (220) (221)
C. S. Hudson, J. Am. Chem. SOC.,47, 270 (1925). C. N. Riiber, Ber., 67, 1797 (1924). T. S. Patterson and J. Robertson, J. Chem. Soc., 300 (1929). E. Fischer and 1,. Beensch, Bet-., 27, 478 (1894). E. Fischer, Ber., 28, 1145 (1895). W. Voss, Ann., 485, 283 (1931). F. Micheel and 0. Littrnann, Ann., 466, 115 (1928). A. Muller, Ber., 64, 1820 (1931).
95
CHEMISTRY OF THE 2-DESOXYSUOARS
When 2-desoxy-~-ribose was treated with one percent methanolic hydrogen chloride it afforded a methyl 2-desoxyriboside mixture which was separated into crystalline a- and @-isomers(A and B, respectively). If 0.1 percent methanolic hydrogen chloride was used, then a third methyl 2-desoxypentoside (C) was obtained. The glycoside C was much 2-Desoxy-~-ribose
/
/I
/% MeOH/HCI
\
HOCH I
(CHdzCO
No reaction
CHIOH
C
1(CHa)aCO A H O C H3
HCOCH~
I
I I TsOCH I TsOCH
OCH,
FIG.5.-Reactions
CH?
I I
TsOCH (CHa)tCO + NaI -OCH
I
+
at 105-110° for 3 hours
--OCHI
CHiOTs
1
+ NaI at 105-110°
I
(CH8)aCO
1 Mole of NaOTs
for 3 hours
No reaction of th Three Forms (A, B and C) of Methyl 2-Desoxy-~-riboside.
more rapidly hydrolyzed by acids than were the glycosides A and B.141 It is a general property of aldose glycofuranosides to be more labile to acids than the corresponding glycopyranosides and so this would seem to indicaie that C was a glycofuranoside. The glycosides A, B and C were separately mechanically shaken with acetone and anhydrous copper sulfate. Glycosides A and B readily formed monoisopropylidene derivatives whereas C was recovered unchanged.ls0 Since it is usual for acetone to condense with adjacent cis hydroxyl groups, this would imply that A and B had pyranose structures and C a furanose structure (see Fig. 5 ) . When the glycosides B and C were treated with toluene-p-
96
W. G. OVEREND AND M. STAGEY
sulfonyl chloride in dry pyridine they both yielded a ditoluene-p-sulfonyl derivative. That from the glycoside C readily underwent exchange with one mole of sodium iodide when heated at 105-110" for 3 hours with excess sodium iodide in acetone, whereas the derivative from B was unaffected by this treatment. This result indicates that the glycoside C must have had a free primary hydroxyl group, the p-toluenesulfonate of which reacted with sodium iodide in acetone, whereas in B the toluenep-sulfonyloxy groups were formed by esterification of secondary hydroxyl groups (see Fig. 5). This could only be so if the glycosides B and C had pyranose and furanose structures respectively. Oxidation of the glycosides A, B, and C by lead tetraacetate resulted in the uptake by both A and B of one mole of oxidant, whereas C was unaffected.141 These results confirm that A and B are pyranosides and that C is a furanoside. Conclusive proof of the structures of the glycosides B and C was obtained by methylation, hydrolysis, oxidation and comparison of the rates of hydrolysis of the lactones so obtained. From the glycoside B a 1,5-lactone was obtained,I4l whereas a l14-lactone was derived from C, showing that the glycoside R had a 1,8pyranose lactol ring and C a 1,4-furanose lactol ring. Since A and B were a- and p-anomers, it followed that A also had a pyranose structure. Independent proof of the structure of B was furnished by the fact that it could be obtained from methyl 2,3-anhydro-p-~-ribopyranoside by a series of transformations which did not affect the lactol ring structure of the initial material or intermediates in the conversion.17* An outstanding property of the 0-glycosides of 2-desoxysugars is their lability towards acids, a property still further enhanced in the 2,3-didesoxysugar series. It was noted by Stacey and that on distillation of methyl 2-desoxy-ap-~-ribofuranoside,polymeric material was formed whenever cautious superheating occurred. Similar effects were observed with the corresponding methyl 2-desoxy-a~-~-glucofuranoside~~ and methyl 2-desoxy-cu~-~-galactofuranoside.~~~ Examination of the product from such a thermal condensation of methyl 2-desoxy-ap-~-ribofuranoside revealed that it was a hard glass, soluble in water but insoluble in the usual organic solvents, and was a nonreducing oligosaccharide. 2. N-Glycosides The study of amine N-glycosides has been stimulated by the occurrence of this type of compound in nucleic acids, certain coenzymes and vitamin BIZ. Amine N-Zdesoxyglycosides have been prepared, using (222) W. G. Overend,
F.Shafizadeh and M. Stacey, J . Chem. Soc., 994 (1951).
CHEMISTRY O F THE
97
2-DESOXYSUQARS
simple aromatic amines such as aniline, and also pyrimidine and purine bases and dimethylbenzimidaaole. Simple Aromatic Amines.-Crystalline anilides of 2-desoxy-~-galactose,22s2 - d e s o x y - ~ - g l u c o s e 2-desoxy-~-xylose,~~ ,~~~~~~~ and 2 - d e s o x y - ~ - ~ ~ ~ and -L-ribose112have been obtained by the usual method of synthesis of -110
-120
-
0
-130
U
Y
-140
-150
- 160' - 65'
5
10
15
20
25
30
35
r
(d)
-75c p
c
-85'
U
I
-95a -105O
- IW
I
1
10' 20
I
30
I
I
40 50 Time, minutes
I
I
60
70
FIG.6.-Mutarotstion of 2-Desoxy-~-galactose p-Toluidide; (a) In Pyridine (c, 1.0); (b) As ( a ) with 1 N H2S04 (one drop) added; (c) In Methanol (c, 1.0); ( d ) As (c) with 0.1 N H&O4 (one drop) added.
sugar anilides, namely, by heating a solution or suspension of the sugar with freshly distilled aniline in absolute or aqueous methanol. Similarly, the p-toluidides of 2-desoxy-~-galactose~~* and 2-desoxy-~-glucose224have been prepared. These derivatives are excellent for the characterization of desoxysugars. They exhibit mutarotation in solution in dry pyridine or absolute methanol, indicating that in all probability they have the N-glycoside rather than the Schiff base type of structure. Figure 6 (223) K. Butler, S. Laland, W. G. Overend and M. Stacey, J . Chem. SOC.,1433 (1 950).
(224) R. Kuhn and A. Dansi, Ber., 69, 1745 (1936).
98
W. G. OVEREND AND M. STACEY
shows the mutarotational changes of 2-desoxy-~-galactose p-toluidide Addition of one drop of 0.1 N (p-toluidine N-2-desoxy-~-galactoside).~~* sulfuric acid results in rapid attainment of the mutarotational equilibrium. Attempts to obtain chemical data to support the optical rotation evidence for the N-glycoside type of structure were unsuccessful, owing to the labile nature of the desoxysugar-base linkage.223 By infrared absorption spectra measurements, however, it was demonstrated that
\
the C=N-
grouping was absent in the products of reaction of 2-desoxy-
/ sugars and aniline, confirming the N-glycoside structure for these compounds. Furthermore, by analogy with other anilides of known structure, it was clear that they possessed the 1,5-(pyranose)-lactol ring st,ructure. Consequently, desoxysugar anilides may be more correctly named as aniline N-2-desoxy-glycopyranosides. The stereochemical configuration of the sugar-base linkage is unknown. Various reactions of the nitrogen-glycosides have proved subject to generalization in the light of the Amadori rearrangement.225 2-Desoxysugar derivatives are unable to undergo this rearrangement and it is considered likely that the specificity of the reaction of desoxyribose with secondary amines to yield colored products is a function of the inability of 2-desoxysugars to participate in the Amadori reaction. Purine and Pyrimidine Bases.-Desoxyribonucleosides have been isolated from natural sources, and the separation of enzymic digests of nucleic acids, on ion-exchange resins, has greatly facilitated the isolation procedures. Attempts t o synthesize these nucleosides have been less successful and a review of their properties will be more appropriate at some future date. Initially, because of its greater availability, 2-desoxyD-glucose was used in model experiments, and the reaction that was investigated was the coupling of an aceto(or benzoyl)-l-bromo-2-desoxysugar with the silver salt of a base. Benzimidazole Derivatives.-In recent years benzimidazole glycosides have become of interest in the chemistry of anti-pernicious anemia factors. This interest prompted Petrow and his colleaguesZ36to prepare benzimidazole glycosides with 2-desoxysugars as the carbohydrate component. Reaction of l-bromo-3,4,6-triacetyl-2-desoxy-~-glucose with 5,6dimethylbenzimidazole silver in hot xylene gave a non-crystalline mixture of a- and &isomers which could not be resolved by fractionation pro(225) H. s. Isbell, Ann. Rev. Biochen., 12, 205 (1943). (226) G. Cooley, B. Ellis, P. Mamalis, V. Petrow and 13. Sturgeon, J . Pharm. and Pharmacol., 2, 579 (1950).
CHEMISTRY O F THE
2-DESOXYSUGARS
99
cedures. However, deacetylation, followed by treatment with picric acid, readily gave a crystalline 5,6-dimethylbensimidazole-l (2‘-desoxyD-glucopyranoside) picrate, from which by acetylation and regeneration of the base, 5,6-dimet hylbenzimidasole- 1 (3’,4’, 6’-triacetyl-2’-desoxy-~glucopyranoside) was obtained in crystalline form. Deacetylation by the Zempl6n-Pacsu method furnished pure 5,6-dimethylbenzimidasole1 (2’-desoxy-D-glucopyranoside). A second possible isomer was not isolated. In contrast to these results, reaction between 5,6-dimethylbenzimidasole silver and l-chloro-3,4-diacetyl-2-desoxy-~-ribose in xylene solution at 100” readily gave a homogeneous 5,6-dimethylbeneimida5ole-l (3’,4‘-diacetyl-2’-desoxy-~-ribopyranoside) , hydrolysis of which furnished 5,6-dimethylbenzimidazole-1 (2’-desoxy-~-ribopyranoside), characterized as the picrate. These observations contrast with those recorded by Davoll and Lythgoe, 149 who obtained two isomeric desoxyribosides and only one desoxyglucoside by condensation of the appropriate acetohalogenosugar with theophylline silver. 3. Oxidation Reactions and Products
In view of their importance in structural determinations, oxidation reactions and products of 2- and 3-desoxysugars have been extensively studied. Oxidation with Bromine Water.-With 2- or 3-desoxy-hexoses or -pentoses, oxidation by bromine water follows the usual course and converts them into t,he corresponding 2- or 3-desoxy-hexonic or -pentonic acids, The oxidation is more rapid if the hydrobromic acid that is produced in the reaction is removed as it is formed, by barium or calIn view of the sensitivity of cium carbonate227or barium 2-desoxysugars to prolonged contact with mineral acids, it is advantageous to adopt this latter, procedure for their oxidation.112 Sometimes for the preparation of desoxy -pentonic and -hexonic acids the method of oxidation (or slight modifications thereof) introduced by G0ebe1~~9 is employed. Lactones derived from 2-desoxysugars behave like normal lactones prepared from hexoses and pentoses. Rates of hydrolysis of d-lactones are much greater than those of the r-type. Whereas hydrolysis of 3 ,4 ,6-trime t hyl-2-desosy-~-galact orlolact one was complete in approximately 100 hours, 3,5,6-trimethyl-2-desoxy-~-galactonolactonewas (227) H. S. Isbell, J. Research Nutl. Bur. Standards, 8, 615 (1932). (228) C . S. Hudson and H. S. Isbell, J. A m . Chem. Soc., 61, 2225 (1929). (229) W. F. Goebel, J. Biol. Chem., 72, 801 (1927).
100
W. 0. OVEREND AND M. STACEY
hydrolyzed exceedingly slowly.lZ7 Similar differences were observed with 3,4,6-trimethyl- and 3,5,6-trimethyl-2-desoxy-~-gluconolactone.~~ Likewise, hydrolysis of 3,4-dimethyl-2-desoxy-~-ribonolactone was comunderplete in 96 hours, whereas 3,5-dimethyl-2-desoxy.~-ribonolactone went negligible hydrolysis. 141 Oxidation with Potassium Permangunate.-Oxidation with potassium permanganate of 2- and 3-desoxyhexose monomethyl ethers, obtained from the cardiac glycosides or by synthesis, has been employed extensively by Reichstein and his colleagues, since valuable information on the structures of the sugars is thereby provided. This reaction results in the formation from either a 2-desoxyhexose 3-methyl ether or a 3-desoxyhexose 2-methyl ether, of one of the isomers of methoxysuccinic acid, which is usually isolated as the diamide. with Oxidation of methyl 3,4-isopropylidene-2-desoxy-ru-~-galactos~de potassium permanganate in the presence of potassium hydroxide afforded methyl 3,4-isopropylidene-2-desoxy-a-~-galacturonos~de (LXXXIV) as its potassium salt. This could readily be converted into methyl 2-desoxya-wgalacturonoside (LXXXV) and both LXXXIV and LXXXV afforded crystalline esters and a m i d e ~ .The ~ ~ ~uronic acid derivative could be reduced by lithium aluminum hydride in ethereal solution to give Although 2-desmethyl 3,4-isopropylidene-2-desoxy-a-~-galactoside.~~~ HFOCH, AH2
HObH BO&H
b
HO-kOOH LXXXIV
AOOH LXXXV
oxy-wgalacturonic acid derivatives readily give the Tollens naphthoresorcinol reactionza1for hexuronic acids, they do not exhibit the brick-red color with basic lead acetate which was described by S t a ~ e as y ~specific ~~ for galacturonic acid. Numerous oxidation studies on various desoxysugars have been made with nitric acid and also with lead tetraacetate and sodium metaperiodate. (230) W.G. Overed, F. Shafizadeh and M. Stacey, J . Chem. Soc., 1487 (1951). (231) B. Tollens, Ber., 41, 1788 (1908). (232) M.Stacey, J . Chem. Soc., 1529 (1939).
CHEMISTRY OF THE 2-DESOXYSUGARS
101
4. Reduction Products 2-Desoxyhexitols are readily obtained by reduction of 2-desoxyhexoses. Reduction by sodium amalgam of 2-desoxy-~-glucose and 2-desoxy-~-allomethylose affords 2-desoxy-~-glucitol (2-desoxy-sorbitol) and 2-desoxy-~-allomethylitol. Catalytic reduction is equally effective and 2-desoxy-~-allitol and 2-desoxy-~-galactitol have been prepared from 2-desoxy-~-allose and 2-desoxy-~-galactose. 2-Desoxy-nglucitol can be obtained also directly from D-glucal."* Wolfrom and his colleagues233effected this same conversion by reducing D-glucal catalytically in a high-pressure bomb. The catalyst employed was nickel supported on kieselguhr. 2-Desoxy-~-glucitol (5 %) has also been obtained together with D-glucitol and D-mannitol (1 %) by the electroreduction of D-glucose under alkaline conditions (i. e., pH 7-10) below 30°.288
5 . Phosphate Esters
To gain an insight into the preparation and properties of phosphoric esters of 2-desoxysugars, Stacey and his colleagues234have synthesized and examined 2-desoxy-~-galactose 3- and 6-phosphoric acid esters. In these compounds it is the hydroxyl group adjacent to the methylene group, and the primary hydroxyl group, respectively, that are esterified, and in this respect these compounds are analogous to 2-desoxy-~-ribose3and 5-(dihydrogen phosphate), both of which are significant components of desoxypentose nucleic acid. Hence the derivatives synthesized were used in model experiments to study hydrolysis rates of the phosphate ester substituent group under acidic and alkaline conditions, and by enzymes. When methy1 1,6-benzylidene-2-desoxy-a-~-galac toside (LXXXVI) was treated with phosphorus oxychloride in pyridine at - B O O , followed by barium it gave amorphous barium methyl 4,6-benzylidene-2-desoxy-a-~-galactoside 3-phosphate (LXXXVII). If diphenylin phosphoryl chloride [diphenylchlorophosphonate, (PhO)2POC1]2aa-240 pyridine was used as the phosphorylating agent, then crystalline (met,hyl (233) hl. L. m-olfrom, M. Konigsberg, F. B. Moody and R. M. Goepp, Jr., J . A n . Chem. SOC.,68,122 (1946). (234) A. B. Foster, W. G . Overend and M. Stacey, J. Chem. SOC., 980 (1051). (235) P. A. Levene and R. S. Tipson, J. Bid. Chern., 106, 113 (1934); 111, 313 (1935); 121, 131 (1937). (236) J. M. Gulland and G. I. Hobday, J . Chem. SOC.,746 (1940). (237) P. Brig1 and H. Miiller, Ber., 73, 2121 (1939). (238) H. Bredereck, E. Berger and Johanna Ehrenberg, Ber., 73,269, 1124 (1940). (239) E. Baer and H. 0. L. Fischer, J . Biol. Chem., 160, 213, 223 (1943). (240) Kathleen R. Farrer,'J. Chem. Soc., 3131 (1949).
102
W. 0. OVEREND AND M. STACEY
4,6-bensylidene-2-desoxy-c~-~-galactoside-3) diphenyl phosphate (LXXXVIII) was obtained. When this compound was subjected to hydrogenation in the presence of catalytic amounts of platinum oxide, cleavage. of the phenyl groups occurred and it was possible to isolate methyl 4,6benzylidene-2-desoxy-cr-~-galactoside 3-(diacid phosphate) (LXXXIX) as a H&OCH$
H&OCH~
I
\ OCHz LXXXVI
-I HCOCH,
H A G
CHO
I
h z OAK
I
HCO-
\
\I
OCHz LXXXIX
xc
H
'
C
I
L
AHzOPO(OPh)2
XCII
XCI
bH&PosHa XCIII
colorless glass, which yielded a crystalline acridine salt. Smooth hydrolysis of the protecting groups was achieved by heating at 100" with 0.01 N sulfuric acid. After purification through the lead salt, S-desoxy-~galactose 3-(dihydrogen phosphate) (XC) was obtained as an amorphous white powder.
CHEMISTRY O F THE
2-DESOXYSUGARS
103
For the synthesis of 2-desoxy-~-galactose6-(dihydrogen phosphate), methyl 3,4-isopropylidene-2-desoxy-c~-~-galactoside (XCI)128was used as initial material. Treatment with diphenylphosphoryl chloride in pyridiphenyl dine gave methyl 3,4-isopropylidene-2-desoxy-a-~-galactos~de 6-phosphate (XCII), from which 2-desoxy-~-galactose 6-(dihydrogen phosphate) (XCIII) was obtained by the reactions outlined for the preparation of the 3-(phosphoric acid ester) (XC). The properties of these compounds were compared with those of *galactose 3- and 6-(phosphoric acid esters). The int,eresting results obtained correlated with those derived from studies of other derivatives of 2-desoxysugars. Recently, Stacey and his have described, in a preliminary report, the chemical synthesis of some phosphates of 2-desoxy-~-ribose. Some phosphoric acid derivatives of 2desoxy-~-ribose have been obtained by enzymic methods of preparation. A reaction analogous to the phosphorolysis of glycogen to D-glucose l-phosphateZ4l has been effected with either hypoxanthine- or guanine-D-riboside, both of which could be split by enzymic phosphorolysis with the formation of D-ribose l - p h ~ s p h a t e . ~The ~ ~successful conclusion of these experiments prompted similar investigations with desoxyribonucleosides. Manson and L a r n ~ e reported n ~ ~ ~ that they obtained the phosphorolysis and arsenolysis of hypoxanthine desoxyriboside by enzyme preparations from calf-thymus gland and rat liver. An acid-stable phosphate ester was isolated as a product of phosphorolysis. Results to be outlined suggested that this ester was 2-desoxy-~-ribose5-phosphate and evidence was obtained for its formation by a mutase type reaction from 2-desoxyD-ribose 1-phosphate. This evidence was extended and reinforced when Manson and L ~ m p e nobtained ~ ~ ~ indications for the formation of desoxy-D-ribose 1-phosphate during the phosphorolysis of thymidine. Consequently the conversions outlined may be depicted as shown.
+ inorganic phosphate AL t 2-Desoxy-~-ribose 1-phosphate + hypoxanthine
Hypoxanthine desoxy-D-riboside
*J 2-Desoxy-~-ribose5-phosphate (240a) R. Allerton, W. G . Overend and M. Stacey, Chemistry and Industry, 952 (1952). (241) C. F. Cori, Gerty T. Cori and A. A. Green, J . Biol. Cheni., 161, 39 (1943). (242) H. M. Kalckar, J . B i d . Chem., 167, 477 (1947). (243) L. A. Manson and J. 0. Lampen, Abstracts Papers Am. Chem. Soe., 114,53C (1948); J . B i d . Chem., 191, 95 (1951). 8, 224 (1949). (244) L. A. Manson and J. 0. Lampen, Federation PTOC.,
104
W. G. OVEREND AND M. STACEY
F r i e d k i i ~has ~ ~shown ~ that reaction A is reversible by demonstrating that hypoxanthine desoxy-D-riboside was formed enzymically from desoxy-D-ribose 1-phosphate and hypoxanthine. Similarly, guanine desoxy-D-riboside could be formed by using guanine in place of hypoxanthinesZ46 That true enzymic synthesis of these desoxy-D-ribosides occurred was substantiated by microbiological assay with Thermobacterium acidophilus R 26. Good agreement was obtained between microbiological and differential spectrophotometric methods of estimation of enzymically produced desoxy-~-riboside.~~7 When nucleoside phosphorylase from rat liver was used, the formation of desoxy-D-riboside with desoxy-D-ribose 1-phosphate appeared to be specific for hypoxanthine and guanine; no synthesis occurred with adenine and pyrimidines. Manson and Lampen248 also observed nucleoside synthesis with the enzyme found in cell-free extracts of Escherichia coli. Determination of the equilibrium constant ( K phosphorolysis = 1/54) indicates that the synthesis rather than the splitting of hypoxanthine desoxy-D-riboside is fav0red.~46 The enzyme catalyzing reaction B (i. e., the conversion of 2-desoxy-~-ribose1-phosphate to the 5-phosphate) can be called a phosphodeso~yribomutase~~* by analogy with phosphoglucomutase. Reversal of this mutase reaction has not yet been demonstrated. The enzymic phosphorolysis of guanine desoxy-D-riboside yielded a labile phosphate esterz46which Friedkinz46was able to purify and isolate in crystalline form as a salt. Guanine desoxyribonucleoside was incubated with nucleoside phosphorylase from calf liver. The free guanine formed was converted to insoluble xanthine, due to the presence of guanase in the enzyme preparation. After extraction of the incubation mixture with n-butanol, inorganic phosphate was removed with magnesia mixture, and the barium salt of the sugar phosphate was precipitated by addition of ether. Crystallization via the cyclohexylamine salt was successful. This is the sugar phosphate designated above as 2-desoxy-~-ribose1-phosphate and used in the experiments on nucleoside synthesis (i. e., reverse reaction A). Several reasons are forwarded to support the structure assigned to this compound. The phosphate ester, which contains one mole of 2-desoxy-~-riboseper mole of phosphorus is extremely acid-labile-50 percent of the phosphorus present is released as inorganic phosphate within 10-15 minutes upon hydrolysis a t pH 4 at 23'. This lability of the phosphate ester linkage points to carbon (245) (246) (247) (1950). (248)
M. Friedkin, J . Biol. Chem., 184, 449 (1950). M. Friedkin and H. M. Kalckar, J . Biol. Chem., 184,437 (1950). E. Hoff-Jplrgeneen, M. Friedkin and H. M. Kalckar, J . BWZ. Chem., 184,461 L. A. Manson and J. 0. Lampen, Federation PTOC.,0, 397 (1950).
CHEMISTRY OF THE
2-DESOXYSKlffARS
105
atom 1 of Z-desoxy-~-riboseas the site of esterification, and indeed, a free aldehyde group is also released upon hydrolysis at pH 4. Consequently, on the basis of origin, analyses and properties, the ester was designated as 2-desoxy-~-ribose1-phosphate. The phosphate ester resulting from the mutase action on 2-desoxyD-ribose 1-phosphate was isolated as the barium salt. Hydrolysis with N hydrochloric acid for 7 minutes liberated 45 percent of the organicbound phosphate. The following data were considered in assigning a structure to this compound. Since it was a reducing sugar, carbon atom 1 was eliminated as the site of esterification. The method of formation from hypoxanthine desoxy-D-riboside, in which the sugar has the furanose form, makes it unlikely that, the suhstit,uent is a t carbon atom 4 of the sugar. Distinction between positions 3 and 5 as possible sites for the phosphate substituen t was obtained by periodate oxidation. As no formaldehyde was formed, it follows that the substituent cannot be a t carbon atom 3 and hence the sugar must be 2-desoxy-~-ribose 5-phosphate. Arsenolysis of hypoxanthine desoxy-D-riboside resulted in the formation of hypoxanthine and free 2-desoxy-~-ribose.p 4 3 Probably the primary product is 2-desoxy-D-ribose 1-arsenate, which decomposes in aqueous media to 2-desoxy-~-riboseand arsenate ions.
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SULFONIC ESTERS OF CARBOHYDRATES BY R. STUART TIPSON Department of Research in Organic Ch,eniistry, Mellon Institute, Pittsburgh, Pennsylvania
CONTENTS . . _ . . . . . . . . . _ . . . _ _ _ _ _ _ _ _ . _ . . . . . 108 I. Introduction. . . . 11. Methods for Sulf rates . . . . . . . . . . . . . . . . . . . . . . , . . . . 111 1. The Use of Metallic Salts of Sulfonic Acids. , . . . . . . . . . . . . . . . . . . . . . . . 1 1 1 2. The Use of Sulfonyl Halides.. . . . . . . . . . . , . . . . . . , , . . . . . . . . . . . . , . . . 112 a. With No Neutralizer.. . . . . . . , . , . . . . . . . . . , , , , , . . . , . . , , , . , . . . 112 b. In Presence of Inorganic Bases.. . . . . . . . . . . . , , , , , , . . , . , . . . . , , c. I n Presence of Organic Bases.. . . . . . . . . . . . , . . . . . . . . , . . . . . , , . . . 110 d. Side-reactions in Presence of Organic Bases.. . . . . , . . , . . . . . . . . , , . . . 117 e. Practical Details of Sulfonylation in Pyridine . . . . . . . . . . . . . . . . . . . . . 127 f. Re-evaluation of Literature Reports. . 3. Other Methods for Sulfonylation.. . . . . . . . . . . . . . . . . . . . . . . . . . . 139 a. Use of the Sulfonic Anhydride.. , , . . . . . . , , . . . . . . 139 b. Use of Anhydro Derivatives of Sugar Alc 111. Physical Properties and Chemical Stability. . . . . . . . . . . . . . _ . . . . . . .140 1, Some Physical Properties of Sulfonic Esters.. . . . . , . . . . . . . . . . . . . . . . . . 140 2. Chemical Stability of Sulfonyl or SuIfoqylox a . Various Acidic Environments. . . . . . . . . . . h. Slightly Acidic, Neutral, and Slightly Basic Environments.. . . . . . . . 152 IV. Reductive Desulfonylation and Desulfonyloxylat,ion , . , , , . . . . . . . . . . . . 1. The Use of Sodium Amalgam ....................... 161 2. The Use of Raney Nickel.. . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . 163 3. The Use of Lithium Aluminum Hydride.. . . . . . . . . . . . . . . . . . . . . . . . . . 164 V. Action of Some Alkaline Reagents on Sulfonic Esters.. . . . . . . . . . . . . . , . . . 165 1. lieaction with Alcoholic Alkalis and with Sodium Methoxide.. . . , . . , . 166 a. Desulfonylation a t the “Isolated” Primary Sulfonyloxy Group. , . . , 166 11. Desulfonylation a t an “Isolated” Secondary Sulfonyloxy Group. . . . . 187 c. Desulfonyloxylation at a “Non-isolated ” Primary Sulfonyloxy Group 170 d. Desulfonyloxylation at a “ Non-isolated ” Secondary Sulfonyloxy Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ . . . . . _ _ . _ . _ 171 .._ e. Scission of Anhydro Rings.. . . . . . . . . . . . . . . . , , . . . . . . . . . . . , . . . , 174 2. Reaction with Ammonia and Amines.. . . . . . . . . . . , . . . . . . , . . . 175 . . a. Desulfonyloxylation with Ammonia. 177 ....... b. Desulfonyloxylation with Amines. , . . . . . . . . . . 3. Reaction with Alkali-Metal Mercaptides and Sul . . . . . . . . . . . . . . . 178 a. Desulfonyloxylation with Alkali-Metal Mercaptides. . . . . . . . . . . . . . . . 178 b. Desulfonyloxylation with Alkali-Meta.1 Sulfide . . . . . . . . . . , . . 179 4. Reaction with Other Hydrolysts.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 VI. Action of Alkali-Metal Halides on Sulfonic Esters. . 1 . Action of Sodium Iodide on Primary Sulfonyloxy Groups.. . . . . . . . . a. Primary Sulfonyloxy Group of a Mono-0-sulfonylated Aldose.. . . . . . 181 11. Primary Sulfonyloxy Groups of a-,W-, or a,o-0-Sulfonylated Alditols 186 c. Primary Sulfonyloxy Group of a Mono-0-sulfonylated Aldonic Acid. 189 d. Primary Sulfonyloxy Group of a-,W-,or a,w-0-Sulfonylated Ketoses 190 107 ,
,
,
,
,
,
, , , , ,
I
I
108
R. STUART TIPBON
2. Action of Sodium Iodide on Secondary Sulfonyloxy Groups.. . . . . . . . . . 191 a. Secondary Sulfonyloxy Groups Non-contiguous to, or .Not Accompanied by, B Primary Sulfonyloxy Group, in Cyclic-Sugar Derivatives 191 b. Secondary Sulfonyloxy Group Contiguous to Primary Sulfonyloxy Group in Alditol and Acyclic-Sugar Derivatives, . , , , , . . . . . . . . . . . . . 201 c. Secondary Sulfonyloxy Group Non-contiguous to Primary Sulfonyloxy Group, in Alditols.. . . . . , , . . . . . . , . , . , . , . . . . . . . . . . . . . . . . . . . . 204 d. Secondary Sulfonyloxy Group Contiguous to Primary Sulfonyloxy Group, in Cyclic-Sugar Derivatives.. ... . . . . . . . . . . . . . . . . . . . . . . . . . 205 e. Secondary Sulfonyloxy Groups (Only), in Sulfonylated Alditols and Aldonic Acids.. . . . . . . . . . . . . , , . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . 205 3. Applicability of Oldham and Rutherford’s Rule.. , . . . . . . . . . . . . . . . . . . . 210 4. Action of Other Alkali-Metal Halides on Sulfonic Esters.. . . . . . . . . . . . . 211 VII. Action of Other Salts on Sulfonic Esters.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
I. INTRODUCTION
Although benzenesulfonyl (CeH&02-; phenylsulfonyl = Ps) chloride was discovered’ just a century ago,a and synthesis of the three toluene~ ~and the two sulfonyla-” (CH3.CeH4So2-;p-tolylsulfonyl = “ t 0 s y 1 ” ; ~Ts) naphthalenesulfonylg~la(CloH7S0r; gnaphthylsulfonyl = rrnasyl”;ll Ns) chlorides followed within the next two decades, it was not until 1907 that a sulfonyl chloride was employed for esterification of a carbohydrate.I2 In that year, the tosy2ation of a degraded cellulose was perfunctorily examined.l 8 G. Chancel, Compt. rend., 36, 690 (1852). (2) Cf.,C. Gerhardt and L. Chioaaa, Ann., 87, 296 (1853); W. Kalle, ibid., 119, 153 (1861);R.Otto and H. Ostrop, ibid., 14i, 365 (1867). (3) ortho- H.Hubner, J. Post, and M. Terry, Ann., 169, 27 (1873);F. Jenssen, ibid., 172,230 (1874). meta- H. Hubner, J. Post, and F. C. G. Miiller, Ann., 169, 47 (1873); J. J. Grifk, Am. Chem. J., 19, 183 (1897). (4) para- W. Jaworsky, 2. Chem., [2],1, 220 (1865). (5) para- R. Otto and 0. von Gruber, Ann., 142,92 (1867). (6) para- C. Miircker, Ann., 136, 75 (1865);Anna Wolkow, Z.Chem., [2],6,321 (1870);H.Beckurts and R. Otto, Ber., 11, 2061 (1878). (7) K.Hess and R. Pfleger, Ann., 607, 48 (1933). (8) Cf.,A. M. Patterson, Chem. Eng. News, 29, 4116 (1951). (9) alpha- J. Kimberly, Ann., 114, 129 (1860);A. Schertel, ibid., 132,91 (1864). (10) alpha-, beta- B. Maikopar, 2. Chem., [21, 6, 710 (1869). beta- P.-T. ClBve, Bull. soc. chim. France, [2],26, 256 (1876). (11) M.Bergmann and W. H. Stein, J . Biol. Chem., 129, 609 (1939). (12) Earlier, n-glucose N-phenylsulfonylhydrasone (H. Wolff, Ber., 28, 160 (1895);R. Kahl, Z . Ver. deut. Zucker-Id., 64, 1091 (1904)), and the N-p-naphthylsulfonylhydraaones of D-ghCOSt? and Icarabinose (Kahl, loc. cit.) had been described. In 1902, E. Fischer and P. Bergell (Ber., 36, 3779 (1902)) prepared N-fl-naphthylsulfonyl-D-“ gdaheptosaminic ” acid. (13)Aktien-Gesellschaft fiir Anilin-Fabrikation, German Pat. 200,334 (1907); Chem. Abstracts, 2, 3410. (1) C. Gerhardt and
SULFONIC ESTERS O F CARBOHYDRATES
109
Then, over another decade elapsed before Od6n14 described the formation of methyl tetra-0-/3-naphthylsulfonyl-a-D-glucopyranosideby the action of ~-naphthalenesulfonyl chloride on methyl a-Dglucopyranoside in quinoline-chloroform. Similarly, he prepared methyl tetra-0-(a-bromocamphor-~-sulfonyl)-a-D-glucopyranoside, 2’,4’,6’-tribroand15 mophenyl tetra-O-(cu-bromocamphor-n-sulfonyl)-D-glucopyranoside, hendeca-0-p-naphthylsulfonylraffinose. Four years later, 1,2:5,6-di-0isopropy~idene-~-0-tosy~-~-glucose and, therefrom, 3-O-tosyl-~-glucopyranose and derivatives were ~ e c u r e d . ’ ~In , ~ ~1926, ethanesuljonyl (C2H5S02-; ethylsulfonyl = “esyl”;l* Es) esters of D-glucofuranose and of D-fructopyranose were isolated ;I9 and these researches were followed by the synthesis of benzenesulfonyl esters20 of sugars in 1932. (Such esters of related polyhydric alcohols had been prepared earlier.21-22)Finally, ~~~~* in 1937, methanesulfonyl (CH,$302--;methylsulfonyl = “ m e ~ y l ” ; Ms) esters were i n t r o d ~ c e d . ~ ~ , ~ ~ OdCn and certain subsequent workers apparently envisaged such sulfonic esters of carbohydrates as merely of use for identiJication purposes via their physical properties (particularly since many of these esters crystallize with comparative ease). However, starting with the work of Freudenberg’s s c h 0 0 l ’ ~ Jin~ ~1922, ~ ~ various aspects of their chemical behavior were accumulated, and the remarkably interesting properties and potentialities of these compounds gradually came to be appreciated. Indeed, because of the kinds of reactions which they can undergo, sulfonic esters have turned out t o be one of the most useful groups of carbohydrate derivatives. Yet many years elapsed before this truth emerged and attained full development. It appears that the initial lack of interest in sulfonic esters of carbohydrat>escan be attributed to the fact that sugar chemists were so accustomed to thinking of sugar esters in terms of carboxylic esters (particularly, acetates and benzoates) that they overlooked an earlier (14) S. OdPn, Arkiv Kenti. Mzneral. Geol., 7, No. 15, 1 (1918);Chem. Abstracts, 14, 2170. (15) S. O d h . Arkiv Kenii. Mzneral. Geol., 7 , No. 15, 23 (1918); Chem. Abstracts, 14,2170. (16) K.Freudenberg and 0. Ivers, Ber., 66, 929 (1922). (17) K . Freudenberg and F. Brauns, Ber., 66,3233 (1922). (18) B. Helferich and M. Vock, Ber., 74, 1807 (1941). (19) I<. Freudenberg, 0. Burkhart, and E. Brrtun, Ber., 69, 714 (1926). (20) J. W. H. Oldham and Jean I<. Rutherford, J . Ant. Chem. Soc., 64,366 (1932) (21) A. Fairbourne and G . E. Foster, J . Chem. Soe., 127, 2759 (1925). (22) Z. Foldi, Ber., 60, 656 (1927). (23) B. Helferich and R. Hiltmann, tlnn., 631, 160 (1937). (24) B. Hrlferich and A. Gnuchtel, Ber., 71, 712 (1938). (25) K . Freudenberg and A. Doser, Ber., 66, 1243 (1923).
110
R. STUART TIPSON
contribution of Ferns and Lapworth’s,26and failed to realize that sulfonic esters are really substituted esters of sulfuric acid and that, consequently, instead of behaving as do carboxylic esters, sulfonic esters usually act and nitric acid. similarly to esters of sulfuric acid, hydrochloric Thus, if R is an allcyl radical, reaction of the ester with sodium hydroxide proceeds as follows: R.Cl R-NOa RsSOd
+ +
+
NaOH = R.OH +NaCl NaOH = R.OH NaNOs 2 NaOH = 2 R.OH Na&3Od.
+
+
Comparative studies on carboxylic and sulfonic esters of some simple, aliphatic alcohols (see p. 167) brought t o light the fact that, whereas an ester of a carbozylicacid (R”CO0H) usually reacts by acyl-oxygen fission :28
or, more precisely (where the curved arrow indicates the direction of the electron shift) :
an ester of a sulfonic acid (R’S0;jB) usually undergoes a2kyZ-oxygen fission:28
resulting in the transitory formation of a carbonium cation. The latter reaction, when completed, may then be expressed by the equation (26) J. Ferns and A. Lapworth, J . Chem. Soc., 101,273 (1912).
(27) F. Ullmann and G . Nadai, Ber., 41,1870 (1908). (28) J. N. E. Day and c. K. Ingold, Trans. Faraday Soc., 87,686 (1941). Balfe, J. Kenyon, and A. L. TArnoky, J . Chenz. SOC.,446 (1943).
M. P.
SULFONIC E S T E R S OF CARBOHYDRATES
RIOS02R’
111
+ NaOH = R.OH + NaSOaR.
This kind of behavior towards nucleophilic reagents is the basis for the many fascinating transformations which can be brought about with sugar derivatives through appropriate treatment of their sulfonic esters.
11. METHODS FOR SULFONYLATION OF CARBOHYDRATES Of the various ways in which sulfonic esters may be synthesized, only twoz9have so far achieved importance in carbohydrate chemistry. 1. The Use of MetaZlic Salts of Sulfonic Acids
This method consist^^^^^^ in the action32of an alkyl halide or sulfate on a metallic salt of the sulfonic acid, for example: RSBr
+ Ag.0S02R'+ ROSOJt' + AgBr.
(1)
Apparently, the first use of this reaction in the sugar series was in the preparationa3of tetra-0-acetyl-l-0-tosyl-"a~'-D-glucopyranose(probably the &derivative actually, by Walden inversion a t carbon atom 1) by the action of silver p-toluenesulfonate on tetra-0-acetyl-a-D-glucopyranosyl bromide in boiling, dry diethyl ether:
7
HCBr
HbAc AcO H H&OAc
-l
TsOCH
HhOAc (Inversion)
(AnOsOrC,H1-p;
AcdH
H&OAo
The corresponding 1-0-mesyl ester has been obtainedz4by shaking a dry benzene solution of the same bromide with finely powdered silver methanesulfonate for two days at room temperature. The same kind of reaction can be brought about at the primary (w-), and sometimes at a secondary, carbon atom. Thus, treatmenta4of a (29) R. S. Tipson, J . Org. Chem., 9, 235 (1944). (30) H. Gericke, Ann., 100, 207 (1856); P.-T. ClBve, Bull. SOC. chim. France, “4, 26, 444 (1876); 29, 414 (1878); Ber., 19, 2179 (1886). (31) F. Ullmann and P. Wenner, Ber., 83, 2476 (1900). (32) Cf.,R. Schiller and R. Otto, Ber., 9, 1638 (1876). (33) B. Helferich and R. Goota, Ber., 62, 2788 (1929). (34) D. J. Bell, E. Friedmann, and S. Williamson, J . Chem. Soc., 252 (1937).
112
R. STUART TIPSON
solution of 3,5-0-benzylidene-6-deoxy-6-iodo-1,2-0-isopropylidene-~-glucose in acetonitrile with silver p-toluenesulfonate (in a sealed tube a t 100” during 12 hours) afforded 3,5-0-benxylidene-l,2-0-isopropylidene-6-0I
I
-+‘-I
I
HCObHJ
AH20Ts
tosyl-D-glucose. Similarly, action of the same salt on 2,3-dibromopropyl acetate in benzene, under reflux during 15 hours, gives361-0-acetyl-2,3di-0-tosyl-D,L-glyceritol.
2. The Use of Suljonyl Halides a. With N o Neutralizer.-This method of sulfonylation involves the action6~9~38*31 of the hydroxylic compound on the sulfonyl halide, as follows: R0.H
+ X.SOeR’ -+
ROS02R’
+ HX.
(2)
I n the simple form given in equation (2), the reaction finds limited use (for example, with certain liquid aliphatic alcohols or molten phenols), but has not apparently been applied to treatment of solid carbohydrates with liquid or molten sulfonyl halides. Several kinds of side-reaction are possible. I n the first place, it is desirable that the rate of reaction between the ester produced and the unreacted, hydroxylic starting-material shall be so low that very little or none of the corresponding ether will be formed by the following type of reaction R’S0sO.R
+ R0.H
--t
R’SOaH
+ R20.
(3)
Such intermolecular or “ cross-linking ” ether formation can u ~ u a l l ybe ~.~~ held to the minimum by conducting the reaction a t room temperature; it (35) J. H. Chapman and L. N. Owen, J . Chem. Soc., 579 (1950). (36) F. Krafft and A. ROOS, Ber., 26,2255 (1892); G. R. Clemo and W. H. Perkin, Jr., J. Chem. Soe., 121, 642 (1922). (37) H. Gilman and N. J. Beaber, J. Am.,Chem. Soc., 46, 839 (1923). (38) F. Krafft and A. Roos, Ber., 26, 2823 (1893); L. Blanchard, Bull. soc. chim. France, 41, 824 (1927). (39) R. Otto, 2. Chem., [2], 2, 655 (1866).
SULFONIC ESTERS OF CARBOHYDRATES
113
does not appear to have been encountered during sulfonylation of carbohydrates under any of the conditions to be described, although, as mentioned later (see p. 117), formation of inner ethers (e.g., anhydrosugar derivatives) sometimes results. However, certain sulfonic esters of sugars and sugar alcohols may be employed for hydroxyalkylation. Thus treatment of potassium apocupreine with 2,3-di-0k.opropyhdene-l-O-tosyl-D,t-glyceritol gave fl,-pO-isopropylidene-fl,rdihydroxy-npropyl-apocupreine. Similarly, interaction of the 3-sodium salt of 1,2:5,6-di-O-isopropylidene-1)-glucose with 1,2:3,4-di-0-isopropylidene-(j-0-tosyl-~-ga~actose in benzene (during 12 hours at loo", and 36 hours a t 128") afforded" the corresponding tetra-0-isopropylidene-"disaccharide" having an ether linkage joining carbon atom 3 of the glucose residue to carbon atom 6 of thc galactose residue.
The second desideratum is that the hydrogen halide evolved in reaction ( 2 ) should have little or no action either on the hydroxylic substance to be esterified or on the desired ester. To minimize this effect, Slotta and Fr~inke4~ aspirated dry air through the hot reaction-mixture, thereby removing hydrogen halide almost as fast as it was liberated. This simple expedient has apparently not been applied in sulfonylation of carbohydrates. Instead, it is customary to add a sufficiency of a compound which will neutralize the hydrogen halide as fast as it is formed. For this purpose, both inorganic and organic (t'ertiary nitrogenous) bases have been employed. 6 . I n Presence of Inorganic Ba~es.--Schotten~~ had introduced the use of sodium hydroxide& this role in benzoylating amines, and Baumann" soon applied it in benzoylating alcohols (including sugars). Four years later, H i n ~ b e r gemployed ~~ it46in preparing sulfonic esters. Essentially, the method consists in shaking the sulfonyl chloride with a solution or suspension of the alcoholic compound in sufficient concentrated aqueous alkali to neutralize the hydrochloric acid liberated. Use of a large excess of 35-50% aqueous sodium hydroxide at 35 t o 50" has been recommendedS47 After pretreatment with zinc chloride plus hydrochloric acid until it became alkali-soluble, cellulose was tosylated13 in this way; and, (40) 11. S.Tipson, Mary A. Clapp, and I,. H. Cretcher, J. Am. Chem. SOC.,66, 1092 (1943). (41) Violet E. Gilbert, I?. Smith, and M.Stacey, J . Chem. Soc., 622 (1946). (42) K. H. Slotta and W. Franke, Ber., 63, 678 (1930). (43) C. Schotten, Ber., 17, 2544 (1884). (44) E. Baumann, Rer., 19, 3218 (1886). (45) 0. Hinsberg, Ber., 23, 2962 (1890); Ann., 266, 178 (1891). (46) Cf.,M. Georgescu, Ber., 24,416 (1891); V. A. Izmail'skii and B. A. Raeorenov, J . Russ. Phys.-Chem. SOC.,62, 359 (1920); Z. Foldi, Bet-., 63, 1836 (1920). (47) D. It. Jackson (to Wyandotte Chemicals Corp.), U. 5. Pat. 2,486,416 (Nov. 1, 1949); Chem. Abstracts, 44,2023. D. R. Jackson and W. K. Langdon (to Wyandotte Chemicals Corp.), [J. S. Pat. 2,486,417 (Nov. 1, 1949); Chem. Abstracts, 44, 2024.
114
R. BTUART TIPSON
later, cellulose itself was so sulfonylated4*,49(after having been converted to alkali-cellulose). The first application to sulfonylation of a monosaccharide derivative was in the preparation of 1,2:5,6-di-O-isopropylidene3-O-tosyl-~-glucoseby Freudenberg and Iversl8in 1922.
Sometimes, the sulfonyl chloride is dissolved in an indigerent, waterimmiscible solvent. Thus, tosylation of cellulose was brought about by treating alkali-cellulose with a solution of p-toluenesulfonyl chloride in carbon tetrachloride,b",61 ben~ene,61-~4or toluene.66 The number of (48) (a) L. Cassella and Co., G. m. b. H., British Pat. 224,502 (1924); Cenlr., 96, I, 1251 (1925). (b) Chemische Fabrik vorm. Sandoz, British Pat. 233,704 (1924); Chem. Abstracts, 20, 670; ( c ) French Pat. 604,433 (1924); Centr., 97, 11, 515 (1926). (d) I. G. Farbenindustrie A.-G., French Pat. 641,043 (Sept. 16, 1927); Chem. Abstracts, 23, 1266. (e) N. M. Sokolova, Khlopchalobumuzhnaya Prom., 7, 38 (1937); Chem. Abstracts, 33, 4792. (f) G. W. Rigby (to E. I. du Pont de Nemours & Co.), U. S. .
Pat. 2,123,806 (July 12, 1938); Chem. Abstracts, 32, 7263. (49) Chemische Fabrik vorm. Sandoa, British Pat. 241,854 (1924); Chem. Abstracts,
20, 3577. (50) Textilwerk Horn Akt.-Ges., German Pat. 396,926 (1922); British Pat. 195,619 (1923); Chem. Abstracts, 17, 3613; French Pat. 563,735 (1923); Centr., 96, 11, 3398 (1924); Chemische Fabrik vorm. Sandoz and A. E. Woodhead, British Pat. 246,609 (1924); Chem. Abstracts, 21, 501; Chemische Fabrik vorm. Sandoz, French Pat. 683,751 (1929); Chem. Abstracts, 24, 5168; G. Tagliani, Bull. soc. ind. Rouen, 68, 418 (1930); Chem. Abstracts, 26, 3173. (51) Chemische Fabrik vorm. Sandoz, British Pat. 325, 961 (1928); Cenlr., 102, I, 384 (1931); German Pat. 521,121 (1929); Chem. Abstracts, 26,2862. (52) G. Eta, T. Nakashima, and I. Sakurads, Cellulose Ind., Tokyo, 2,47 (1926); Centr., 98, I, 1429 (1927); G.Kita, I. Sakurada, and T. Nakashima, Kunstsloffe, 17, 269 (1927); C a t r . , 99, I, 900 (1928). (53) I. Sakurada and T. Nakashima, Sci. Papers Znst. Phys. Chem. Research (Tokyo), 6 , 214 (1927); Centr., 99, I, 2143 (1928). (54) Cj.,G. Tagliani, J. Sac. Dyers Colourisls, 41, 165 (1925); Textile World, 67, 3547 (1925); Melliand8 Teztilber., 6, 425 (1925); 7, 765 (1926); U. s. Pat. 1,633,617 (June 28, 1927); C h . Abstracts, 21, 2805. (55) Chemische Fabrik vorm. Sandoz, French Pat. 690,280 (1930); Cenlr., 102, I, 526 (1931); German Pat. 645,323 (1929); Chem. Abstracts, 26, 3121.
SULFONIC ESTERS OF CARBOHYDRATES
115
sulfonyl groups introduced per glucose residue depends on the precise conditions employed : a t temperatures below 30°, Sakurada and Nakashimas*found that a single treatment gave a product corresponding t o somewhat less than a mono-ester, but repeated esterification gave a mixture of mono- and di-ester; above 30°,the degree of tosylation decreased, indicating partial detosylation by the alkali (see p. 166). (On sulfonylation, cellulosic fibers are immunised to direct, sulfur, and vat dyes, suggesting use in design d ~ e i n g . ~Interest ~ - ~ ~ in such possible industrial applications has undoubtedly stimulated academic research on sulfonic esters of carbohydrates.) In a manner similar to the above, starchS7has been sulfonylated by shaking a suspension of it, in sodium hydroxide solution, with a benzene solution of the sulfonyl chloride. Another modification of possible utility consistsbs in addition of acetone, which dissolves sulfonyl chlorides and certain alcoholic compounds and which is itself partly soluble in the sodium hydroxide solution; thus, by slow addition of the latter a t 1 to 3", followed by stirring at this temperature during a further 5 hours, a 64% yield of tri-0-tosyl-glyceritol was obtained from gly cer01. Obviously, these methods are inapplicable t o esterification of free sugars and of alkali-labile glycosides and esters (including the resultant sulfonic esters) , but may be employed with sugar alcohols, non-reducing di- and oligo-saccharides, and alkali-stable glycosides and acetals (e.g., certain-0-isopropylidene derivatives), Sodium c a r h a t e , also used in aqueous solution as neutralizer in preparing many sulfonic csters27~42~sB~@0 does not appear to have been used in sulfonylation of carbohydrates; as with sodium hydroxide, its value lies in the avoidance of certain sidereactions often encountered when tertiary nitrogenous bases are employed; furthermore, it is less likely to cause subsequent desulfonylation than is sodium hydroxide. A related method, which also has apparently not been employed for sulfonylation of carbohydrates, involves".a* portionwise addition of finely powdered potassium hydroxide to a stirred solution of the alcoholic compound plus the sulfonyl chloride in dry diethyl ether, below 4'. In another modification,83the sulfonyl chloride, dissolved in the molten alcoholic compound, is added to the sodium derivative of the latter. (56) Cf., W. Herzog, Monatschr. Teztil-Znd., 46, 480 (1930); Chem. Abstracts, 26, 3925. (57) A. A. Houghton and Imperial Chemical Industries, Ltd., British Pat. 493,513 (Oct. 6, 1938); Chem. Abstracts, 33, 2626. (58) F. Drahowzal and D. Klamann, Monatsh., 82,452 (1951). (59) F. Ullmann and 0. Loewenthal, Ann., 332, 62 (1904). (60) F. Ullmann and S. M. SanB, Ber., 44, 3730 (1911); S. M. Sane and S. S. Joshi, J . Chem. Soc., 126, 2481 (1924); S. M. SanB, S. N. Chakravarty, and B. N. Parmanick, J. Indian Chem. SOC.,9, 55 (1932). (61) F. L. Hahn and H. Walter, Ber., 64, 1531 (1921). (62) H. Gilman and N. J. Beaber, J . Am. Chem. Soc., 41, 518 (1925). (63) H. Erdmann and C. Suvern, Ann., 276, 230 (1893); P. Bourcet, Bull. SOC. chim. France, [4], 11, 361 (1912).
116
R. STUART TIPSON
A similarly limited procedure is t o allow the sulfonyl halide to react with a sodium alkoxide in dry diethyl ethere4or dry benzene.65 Thus, a solution of 1,2:5,6-di-0-isopropylidene-~-glucose in dry diethyl ether was treated10 with sodium, and the resulting monosodium compound was permitted to react with p-naphthalenesulfonyl chloride, yielding the 3-O-p-naphthylsulfonyl derivative, The same authorsIg synthesized 1,2 :4,5-d~-0-~sopropyl~den~-O-tosy~-~-fructopyranose in a similar manner. Muskate"prepared the potassium salt of 1,2 :5,6-di-O-isopropylideneD-glucose in liquid ammonia, removed the latter, dissolved the salt in dry diethyl ether, and then allowed it to react with p-toluenesulfonyl chloride to give the 3-O-tosyl derivative. These procedures involving the introduction of an alkali-metal are obviously of little or no value in preparing the sulfonic esters of such substances as partially acylated sugars or alkali-sensitive glycosides, except when liquid ammonia6ais the solvent employed during formation of the metal compound. c. I n Presence of Organic Bases.-Tertiary nitrogenous bases which have been used in the formation of sulfonic esters of alcohols (and phenols) include pyridine167*68q ~ i n o l i n e , ~and ~ . ' ~diethylaniline.27.eo.68Thus, the first tosyl ester of a sugar derivative, viz., 1,2:5,6-di-O-isopropylidene-3O-tosyl-D-glucose, was obtainedLein 85 % ' yield by treating 1,2:5,6-di-Oisopropylidene-D-glucose with 1.5 molecular proportions of p-toluenesulfonyl chloride (in dry pyridineduring 14 hours at 30'). pretreated with pyridine, and starch,? similarly pretreated, were then sulfonylated in this way. is Sometimes, an extraneous, dry, inert or non-polar solvent14~1b~70 added. Thus, methyl tetra-0-P-naphthylsulfonyl-a-D-glucopyranoside was synthesizedL4in quinoline-chloroform a t 40°, and cellulose was sulfonylated by means of a sulfonyl halide plus pyridine, quinoline, triethylamine, or diethylaniline, in the presence of nitrobenzene or other indifferent solvent. Raymond and Schroeder?* successfully employed acetone as added solvent in tosylation of 1,2:3,4-di-O-isopropylidene-~(64) R. Hubner, Ann., 223, 235 (1884); cf., Ref. 32. (65) R. Otto, Ber., 19, 1832 (1886). (66) I. E. Muskat, J . Am. Chem. SOC.,66, 2449 (1934). (67) F. Reverdin and P. Crbpieux, Her., 36, 1439 (1902); T. S. Patterson and J. Frew, J . Chem. Soc., 89, 332 (1906). (68) F. Ullmann and W. Bruck, Ber., 41, 3932, 3939 (1908). (69) P. Karrer and W. Wehrli (to Chemische Fabrik vorm. Sandoe), U. S. Pat. 1,824,671 (Sept. 22, 1932); Chem. Abatracta, 26, 318. (70) D. L. Tabern and E. H. Volwiler, J . Am. Chem. SOC.,66, 1139 (1934). (71) Chemisehe Fabrik vorm. Sandoz, British Pat. 284,358 (1927); Chem. Abstracts, 22, 4834. (72) A. L. Raymond and E. F. Schroeder, J . Am. Chem. ~ o c . 70, , 2785 (1948).
SULFONIC ESTERS OF CARBOHYDRATES
117
galactose, and dichloromethane in the unimolar tosylation of methyl 8-D-ghcopyranoside (to yield its 6-0-tosyl derivative). Ohle and D i c k h a u ~ e claimed r~~ that presence of chloroform in the reaction mixture improves the yield of the 5,6-di-0-tosyl derivative on tosylating 1,2-0isopropylidene-D-glucofuranose in dry pyridine ; the effect may be attributable to consequent diminution of side-reactions, and needs further study. It would seem that a solvent such as which tends to throw pyridinium chloride out of solution in pyridine (as well as t o lessen the degree of ionization of dissolved pyridinium chloride), would be more efficacious (see p. 134). On comparing the effect of added solvents on the formation of methyl p-toluenesulfonate (from methanol plus p-toluenesulfonyl chloride in the solvent, with stirring and dropwise addition of 2 molar equivalents of pyridine at 1 to 3’) the yields of ester were:74with carbon tetrachloride, 71 %; with chloroform, 72%; and with diethyl ether, 87 % of the theoretical yield. However, the respective reaction times were 2,2.5, and 1.5 hour#, so the results may be inconclusive. d . Side-reactions in Presence of Organic LZuses.-In the preparation of sulfonic esters in the presence of, e.g., pyridine, at least four different types of side-reaction (usually undesired) van occur. One of these is ether-f0rmation,26as in equation (3); it appears not to have been encountered as a n intermolecular process in sulfonylntion of carbohydrates, but, under rat her drastic (or prolonged) conditions, intramolecular formation of a n inner cyclic ether (“dehydration”) sometimes occurs. Thus, when 1,2-0-isopropyhdene-~-glucofuranose is t r e a t e ~ lwith ~ ~ .excess ~ ~ (3.3 molar proportions) of p-toluenesulfonyl chloride in boiling pyridine-chloroform during 8 hours, there is isolated, instead of the 3,5,6-tri-O-tosyl derivative : obtained a t do”, 3,G-anhydro-1,2-O-~sopropyl~dene-5-~-tosyl-~-gl~i~~o~e
I I
HCOH HOCHi
Another example is the formation of an anhydro-l,6-di-O-benzoyl-di-Otosyl-o-hexitol (along with the expect,ed 2,3,4,5-tetra-O-tosyl derivative) (73) H. Ohle and E. Dickhiiuser, Ber., 68, 2593 (1925). (74) F. Drahowxal and D. KIamann, Monatsh., 82, 460 (1951). (75) C:f., H. Ohle, L. von Vargha, nnd H. Erlbach, Ber., 61, 1211 (1928).
118
R. STUART TIPSON
on treatit~g'~-'~ 1,6-di-O-benzoyl-~-mannitolwith 4.4molar proportions of p-toluenesulfonyl chloride in pyridine during 96 hours a t 35-40'. Similarly, the formation of a cyclic ether on some of the glucose residues of hydroxyethylcellulose when it is tosylated in presence of pyridine (for only 3 hours a t 25") has been postulated;*Oa tentative formulation, involving intra-alkylation by the highly reactive P-tosyloxyethyl group, is as follows :
:q
iOTs 1------_ _ _ _ _ _ _€$OCH I CH, HC-
1
CH
I-
-0CH
I
HCOH
I
___)
I
r O C IH CHn HC-
I
HCO
CHI
I
HCO-
L-OAH2
I O L H ,
This is feasible, because the hydroxyl of the hydroxyethyl group is tosylated much more rapidlys1than the secondary hydroxyl groups of the glucose residues. The second kind of side-reaction consists in formation of the pyridinium quaternary salt,2B as in equation (4). Recognition of this type of
R/+
-
OSO&,Hr
reaction has not often been recorded in the numerous reports on sulfonylation of carbohydrates in pyridine, and it is evidently of minor importance in most instances ;but there is a possibility that its occurrence has been overlooked in certain cases, since any water-soluble quaternary salt formed would be discarded in aqueous washings when isolation of the desired product is effected merely by precipitation with water. Thus, salt-formation may account for the poor yields obtained in some sulfonylations. Apparently, this side-reaction is most likely to occur when the carbohydrate to be sulfonylated has a free hydroxyl group at carbon atom 1 or (76) A. Miiller, Ber., 66, 1051, 1055 (1932). (77) A. Muller and L. von Vargha, Ber., 66, 1165 (1933). (78) P. Brig1 and H . Griiner, Ber., 66, 1945 (1933). (79) A. Miiiler, Ber., 67, 830 (1934). (80) C. W. Tagker and C. B. Purves, J . Am. Chem. Soc., 71, 1023 (1949). (81) P. L.-E. Fournier, Ann. chirn., [12], 7, 75 (1952).
SULFONIC ESTERS OF CARBOHYDRATES
119
if this group is already substituted by a halogen atom. Thus, treatment of 2,3,6-tri-0-methyl-~-glucopyranose with 2.2 molar proportions of p-toluenesulfonyl chloride in pyridine, during 3 days at 15-20', givess2a 36 % yield of 2,3,6-tri-0-rnethyl-4-O-tosyl-~-glucosylpyr~d~n~um p-toluenesulfonate (and, as will be seen later (p. 125), this reaction is probably preceded by chlorination a t carbon atom 1).
";I - "-.1:g
HSCOCH HCOCHa
C;H,SOa
HaCOCH
HCOH
HCOTs
HCO
HCO
I
I
CHaOCH,
CH~OCHI
Similarly, when 3,4,6-tri-0-acetyl-a-~-glucosyl chloride is tosylated in pyridine-chloroform during 48 hours at room temperature, one product (obtained in 53 % of the theoretical yield) is its 2-0-tosyl d e r i v a t i ~ ebut ,~~ 3,4,6-tri-0-acetyl-2-O-tosyl-~-g~ucosy~pyridinium p-toluenesulfonate was isolated84from the mother liquor. This is in agreement with an earlier discovery85 that 2,4,6-tri-0-acetyl-3-O-tosyl-a-~-glucosyl bromide reacts with dimethylaniline a t 100' to give the corresponding quaternary bromide (without occurrence of any effect a t the 3-tosyloxy group). Quaternary-salt formation can also occur, particularly a t elevated temperatures, if the sulfonylation product has a primary sulfonylozy group. Thus, 2,3-0-isopropy~idenel-O-tosyl-~,~-glyceri~o~ readily reacts86 with hot pyridine to give the corresponding pyridinium p-toluenesulf onate :
I
I
-
c
Studies on sulfonic esters of sugar alcohols have revealed that sulfonic (82) (83) (84) (85) (86)
K. Hem and F. Neumann, Bm., 68, 1360 (1935). Thelma M. Reynolds, J . Chem. Soc., 2626 (1931). Thelma M. Reynolds, J . Chem. Soc., 223 (1933). H. Ohle and V. Marecek, Bet., 63, 612 (1930). P. Karrer and W. Wehrli, 2.angew. Chem., 89, 1509 (1926).
120
R. STUART TIPSON
esters of primary alcohols (‘quaternize” much more readily than do those of secondary alcohols. Thus, boiling pyridine is without effectx7 on 1,3:4,6-di-0-beneylidene-2,5-di-0-tosyl-dulcitol during 1.5 hours, but, under the same conditions, 2,3,4,5-di-0-isopropylidene-l,6-di-O-tosyldulcitol gives a 78 % yield of the corresponding di-pyridinium derivative. affordsss 1,2,3,4Similarly, tetra-~-acetyl-6-0-mesyl-/3-~-glucopyranose tetr~-acetyl-6deoxy-~-D-glucose-6-pyridiniummethanesulf onate. This principle has been employedxgfor determination of the percentage of free primary hydroxyl groups in a partially acetylated cellulose, by tosylating and then treating with pyridine, 3-picoline, or isoquinoline at 100’. It should be noted that formation of pyridinium salts by the action of silver p-toZuenesulfonate in pyridine on glycosyl halides, or (less readily) on wdeoxy-whalogeno-glycose derivatives, had been discovered earlier. Thus, trcatment90 of tetra-0-acetyl-a-D-glucopyranosyl bromide with these reagents at r o o m temperature rapidly yields tetra-0-acetyl-P-D-glucopyranosylpyridiniump-toluenesulfonatc, isolated as crystals, together with its syrupy a-isomer; by similar treatment during 3 hours at the boiling temperature, methyl tri-0-acetyl-0-bromo-6-deoxy-~-~-glucopyranoside gave a 70 % yield of methyl tri-O-acetyl-6-deoxy-~-~-glucopyranoside-6pyridinium p-toluenesulfonste. Shaking of 2,4,6-tri-0-acety1-3-O-tosyl-a-~-glucosyl bromide with silver sulfate in pyridine during 48 hours at room temperature affordede1-*2 a somewhat related pyridinium compound.
As regards this side-reaction of quaternary-salt formation during sulfonylation in pyridine, Sekera and Marvelg3have pointed out that it usually proceeds t o only a minor extent if the reaction is performed at 0”. For polyvinyl sulfonic esterslQ4 the rate of quaternary-salt formation with pyridine is in the order: benzenesulfonate > p-toluenesulfonate > methanesulfonate. Formation of quaternary salts was found94 to proceed most readily with pyridine and its p- or 7-substituted derivatives; less readily with a-substituted pyridines; and only slightly with tertiary alkyl- or aralkyl-amines such as triethylamine, diethylaniline, and N-methylmorpholine. For example, the tendency to “ quaternize ” with simple sulfonic esters decreasesgsin the order: 2-methylpyridine > 2,4-dimethylpyridine > 2,G-dimethylpyridine (2,6-lutidine). The last (87) W. T. Haskins, R. M. Hann, and C. S. Hudson, J . Am. Chem. SOC.,64,132 (1942). (88) B. M.Iselin and J. C. Sowden, J . Am. Chem. Soc., 78, 4984 (1951). (89) F. N. Hayes and C.-H. Lin, J . Am. Chem. SOC.,71, 3843 (1949). (90) H.Ohle and K. Spencker, Ber., 60, 1836 (1926). (91) H.Ohle, V. Marecek, and W. Bourjrtu, Ber., 62, 833 (1929). (92) Cf.,H. Ohle, Biochem. Z., 131, GO1 (1922);H. Ohle and W. Bourjau, Ber., 68,721 (1925). (93) V. C.Sekera and C . S. Marvel, J . Am. Chem. Soc., 66,345 (1933). (94) D.D.Reynolds and W. 0. Kenyon, J . Am. Chem. Soc., 72, 1587 (1950). (95) D.D.Reynolds and W. 0. Kenyon, J . Am. Chem. Soc., 72, 1593 (1950).
SULFONIC ESTERS O F CARBOHYDRATES
121
quaternizes so much more slowly than does pyridine that its use permits ready formation of certain cyclic ethers, as a preparative method. Perhaps, quaternization may be completely obviated by use of a base still more stericnlly-hindered, e . g . , 2,4,&trimethyIpyridine (2,4,G-collidirie"G). The use of " pyridine bases " instead of pyridine in the unimolar tosylatioii of a-D-glucose led, however, to no improvement in yield,Y7and about 3 times the volume was needed for dissolution of a given weight of the sugar. The third, and, as far as carbohydrates are concerned, the most important type of side-reaction is that of alkyl-chloride formation or "chlorination," in the sense R.OH + 11.C1.
That sulfonyl chlorides can function as chlorinating agents had been proved long before the above phenomeiion mas encountered in the carbohydrate field. Thus, on heating sodium wetate with excess p-toluenesulfonyl chloride, acetyl chloride9*results; similarly, henzoyl chloride is formed27 from benzoic acid on treatment with p-toluenesulfonyl chloride in pyridine a t 100". Phenols (e.g., in the presence of ~ y r i d i n e ' ~ or diethylanilineZ760,68) may likewise he so chlorinated. According to Borsche and F e ~ k ethe , ~sulfonyl ~ chloride i s not itself the chlorinating agent; instead, the mechanism of the reartion (in the presence of diethylaniline) was thought t o be as follows: 1tO.H
+ CI.OzSC7H7 + It0802C7H7 + HCl C6H5
R.0S02C7H7
I
+
N
Et
+
/ \
Et
Et
Et
I
/ \
/ \
6S02C~H7 Et
CaHs
CeH.5
R-N+
R-&+
(ISO2C7H7 Et
+ HCI
4
R.CI
I
+
+ CTH~SO~H.
N
Et
/ \
Et
Such chlorination of alcohols has also beeii observed;lOO~lO1 a simple example is the chlorinationlooof 2-phenoxyethanol : (96) C. G. Bergstrom and S. Siegel, J . Am. Chem. SOC.,74, 145, 254 (1952). (97) E. Hardegger and R. M . Montrtvon, Helv. C h z m Acta, 29, 1199 (1946). (98) Chemische Fabrik von Heyden, A.-G., German Pat. 123,052 (hug.29, 1900); Centr., 72, 11, 518 (1901). (99) W. Borsche and E. Feske, Ber., 60, 157 (1927). (100) C. L. Butler, Alice G. Renfrew, L. H. Crrtcher, and B. 1,. Souther, J . Am. Chem. Soc., 69, 227 (1937). (101) G. M. Ilennett and M. M. Hafez, J . Chent. Soc., 652 (1941); H. Rapoport, J. Am. Chenz. Soc., 68, 341 (1946); H. Rapoport (to Heyden Chemical Corp.), U. S. Pat. 2,441,595 (May 18, 1948); Chem. Abstracts, 42, 7323.
122
R. STUART TIPSON
The alcohol here undergoes alkyl-oxygen fission and the resulting carbonium cation combines with anionic chlorine. This fission is facilitated
FIG.l.-Effect106 of Temperature on Uptake of Sulfur, Chlorine, and Nitrogen by Cuprammonium Rayon (on Tosylation in Presence of Pyridine during Four Days). (Taken from K. Heis and N. Ljubitsch, Ann., 607, 62 (1933).)
by increase in the electron-releasing properties of the alkyl group. By raising the temperature, the tendency for chlorination to occur is increased; thus, treatment of glycerol a-monochlorohydrin with p-chlorobenzenesulfonyl chloride at 25-35' giveslo2its di-ester, but at 100' a mixture of 1,3-dichloro-2-0-p-chlorophenylsulfonyl-l,3-dideoxy-glyceritol plus 1,2,3trichloropropane results. Prolonged heating increases the proportion of (102) M. Kulka, J. Am. Chem. SOC., 72, 1215 (1960).
SULFONIC ESTERS O F CARBOHYDRATES
123
the latter. (Instead of being merely a “neutralizer,” the pyridine exerts a catalytic effect in esterification. Particularly at low temperatures, its function is probablylo3 to promote removallo‘ of the proton from the hydroxyl group, so that the carbon-oxygen bond is not disturbed and esterification occurs.) I n 1933, Hess and Pfleger’ found that, in presence of pyridine, tosylation of starch results in the 2,3,6-tri-O-tosyl derivative (containing less than 1% of chlorine) if the reaction is performed by shaking a t 18-20’ for 9 days; but, at higher temperatures, the product is essentially a monochloromonodeoxy-di-0-tosyl derivative. On the other hand, with ceZZulo~e7~~0~ an ester containing 2 tosyl groups per glucose residue (and only 0.2% of chlorine and 0.7 % of nitrogen) is obtained on treating 1 mole with 10 moles of p-toluenesulfonyl chloride in 40 moles of pyridine during 4 days at 15-20’ (see Fig. 1). I n attempts to introduce a third tosyl group, chlorination followed so readily during this treatment that a triO-tosyl derivative was not isolated; thus, treatment at 70’ for 13 days gave a product containing 10.91% of sulfur, 11.9397, of chlorine, and 0.90% of nitrogen (see, also, Fig. 1). Furthermore, if the di-ester is heated with pyridinium chloride in pyrldine during 2 days a t 70°, a product containing 13.4% of sulfur, 11.36% of chlorine, and 3.63% of nitrogen is obtained. Mesylation of cellulose proceeds in an analogous manner. lo6 I n the following year, Levene and Tipsonlo7discovered that chlorination of a monosaccharide derivative can also occur: on tosylation of uridine in pyridine during 18 hours a t room temperature, 3’-(5-chloro-5-
deoxy-2,3-di-0-tosyl-/3-~-ribofuranosy~)-uracil results. Practically simultaneously, methyl 4-O-acetyl-6-chloro-6-deoxy-2,3-di-O-tosyl-~-~-glucoside was ~ b t a i n e d (in ~ ~48.5% *~~~ ~ on attempting to tosylate the yield) (103) M.P.Balfe, M. A. Doughty, J. Kenyon, and R. Poplett, J . C h m . SOC.,605 (1942). (104) W. Gerrard, J . Chem. SOC.,218 (1940). (105) K. Hess and N. Ljubitsch, Ann., 607, 62 (1933). (106) M. L. Wolfrom, J. C. Sowden, and E. A. Metcalf, J . Am. Chem. SOC.,68, 1688 (1941). (107) P. A. Levene and R. S. Tipson, J . Biol. Chem., 106, 419 (1934). (108) 0.Littmann and K. Hess, Ber., 67, 519 (1934). (109) K. Hess and W. Eveking, Ber., 67, 1908 (1934).
124
R. STUART TIPSON
free hydroxyl group of methyl 4-0-acetyl-2,3-di-0-tosyl-a-~-glucoside, using 1.5 molar proportions of ptoluenesulfonyl chloride in pyridine during 23 hours at 100";a t 48", unchanged starting material was allegedly recovered. (It should be noted, however, that chlorination does not occur with the corresponding 8-glucoside, which is readily tosylatedlogt o methyl 4-0-acetyl-2 ,3,6-tri-0-t osyl-8-D- glucoside.) 0t her examples of such chlorination have since been accumulated.34~110-"2Thus, attempted t ~ s y l a t i o nat~ ~positions 5 and 6 of 1,2-O-isopropylidene-3-0-methyl-~glucofuranose gave the 6-chloro-6-deoxy-5-0-tosyl derivative; however, the 5,6-di-O-tosyl derivative has since been isolated113in 52% yield by employing suitable operating conditions, viz., reaction during 4 days at 40' with alcohol-free, dry chloroform as diluent. It will be noticed that, in all the foregoing examples involving monosaccharide derivatives, a free primary hydroxyl group is eventually replaced by chlorine. Occurrence of the same phenomenon probably accounts for the variable results previously obtained on dimolar tosylation114 of 3-O-acetyl-l,2-O-isopropylidene-D-glucofuranose. (Examples in which it appears likely that primary benzoyloxy groups have been replaced by chlorine, on attempted tosylation in pyridine, have also been encountered.116,116) The next advance was made by Hess and Stenzel,117who proposed a mechanism of chlorination slightly different from Borsche and F e s k e ' ~ . ~ ~ They, too, decided that chlorination is increased in extent by raising the temperature' and that it is preceded by sulfonylationg9at the hydroxyl group concerned, but concluded that it occurs according to equation (6) : R.OSO&?H,
+ CrHbNH.Cl+
R.C1
+ C&HSNH.SO&?Hr.
They found that treatment of methyl a-D-glucopyranoside with 6 molar proportions of p-toluenesulfonyl chloride in pyridine a t 20" during 16 days gives an almost theoretical yield of the tetra-0-tosyl derivative, whereas reaction at 35" during 4 days, or a t 75" during only 2 days, gives 25 % and 29 % yields, respectively, of a monochloro-monodeoxy derivative which, rather surprisingly, was found to be methyl 4(?)-chloro-4(?)-deoxy-tri-Otosyl-a-D-"glucoside" (or -D-galactoside, if Walden inversion had occurred at carbon atom 4). Thus, chlorination here proceeds first at a (110) (111) (112) (1942). (113) (114) (115) (116) (117)
P. A. Levene and R. S. Tipson, J. Biol. Chem., 109, 623 (1935). P. A. Levene and R. S. Tipson, J. Biol. Chem., 121, 131 (1937). J. K. Wolfe, R. M. Hann, and C . S. Hudson, J . Am. Chern. Soc., 64, 1493 E. Vischer and T. Reichstein, Helv. Chim. Ada, 27, 1332 (1944). H. Ohle, E. Euler, and R. Lichtenstein, Ber., 62, 2885 (1929). H. Ohle, H. Erlbach, H. Hepp, and G. Toussaint, Ber., 62, 2982 (1929). P. A. Levene and A. L. Raymond, J . B i d . Chem., 107,75 (1934). K. Hess and H. Stenzel, Rer., 68, 981 (1935).
SULFONIC E S T E R S O F CARBOHYDRATES
125
secondary carbon atom. Furthermore, on treatment a t 80" during 4 days, chlorination a t the primary carbon atom occurs, too, giving a 54% yield of the 4(?),6-dichloro-4(?),6-dideoxy-di-0-tosylderivative (said t o be identical with the product previously obtainedl18 by tosylating methyl 4(?),6-dichloro-4(?),6-dideoxy-m-~-"glucoside"~~~). The same compound was also isolated*I7 after heating the tetra-0-tosyl derivative with pyridinium chloride in pyridine during 2 days at 95", although this reagent has no effect on methyl a-D-glucopyranoside under similar conditions. The behavior of methyl m-D-glucopyranoside, on tosylation, thus resembles that of cellulose (but the latt,er presumably has no free hydroxyl groups a t carbon 4 of all but one of its chain-linked glucose residues). On the other hand, methyl 0-D-glucopyranoside behaves more like starch: t ~ s y l a t i o n , "even ~ for 4 days a t 95" gave only a 16% yield of the 4(?),6dichloro-4(?),6-dideoxy-di-0-tosylderivative; a 44 % yield of the monochloro-monodeoxy-tri-0- tosyl derivative was obtained after 2 days a t 65'; and 4 days' treatment a t either 35" or 20' resulted in practically quantitative yields of methyl tetra-0-tosyl-P-D-glucopyranoside. Finally, the discovery was made that, if the hydroxyl group a t carbon atom 1 of a n aldose is free, attempted sulfonylation may result in chlorination at this position. (This behavior is somewhat analogous t o the formation of tetra-0-acetyl-D-glucopyranosyl chloride by the action120 of acetyl chloride on D-glUCOSe, and resembles the preparation of 2,3 :5,6-diO-isopropylidene-D-mannosyl chloride by the interaction12' of thionyl chloride with 2,3:5,6-di-O-isopropylidene-~-mannose in dry pyridinechloroform. A hint as to such chlorination of the latter compound with p-toluenesulf onyl chloride in pyridine is contained in a n article published122in 1923; and the peculiar results obtained on attempted unimolar tosylation of 2,3,0-isopropylidene-~-ribofuranose had been reported12' ten years later.) In 1937, Hess and I
B. Helferich, G. Sprock, and E. Bcsler, Rer., 68, 886 (1925). 1%.Helferich, A. Lowa, W. Nippc, and H. Riedel, Ber., 66, 1083 (1923). A. Colley, Compt. rend., 70, 401 (1870); Ann. chim.p h y s . , [4], 21,363 (1870). K. Freudenberg, A. Wolf, E. Knopf, and S. H. Zaheer, Ber., 61, 1743 (1928). K. Freudenberg and R. M. Hixon, Ber., 66, 2119 (1923). P. A. Levene and E. T. Stiller, J . Biol. Chern., 102, 187 (1933). K. Hess and L. Kinae, Ber., 70, 1139 (1937). E. Elizabeth Percival and E. G. V. Percival, J . Chem. Soc., 1585 (1938).
126
R. STUART TIPSON
methanesulfonyl chloride t o a suspension of anhydrous D-glucose in dry pyridine at O”, shaking a t this temperature for a short time (until the glucose dissolved), and then preserving in the refrigerator during 14 hours. I n contrast, only a 36 % yield of 2,3,4,6-tetra-0-tosy~-D-glucosy~ chloride resulted126on dropwise addition of a dry chloroform solution of p-toluenesulfonyl chloride t o a cooled, stirred suspension of the anhydrous sugar in dry pyridine, followed by shaking a t room temperature for 5 days; this is somewhat surprising inasmuch as, for sulfonic esters of polyvinyl alcohol, t he rates a t which the sulfonyloxy groups are replaced by chlorine, on reaction with pyridinium chloride, decrease‘27in the order : methylsulf onyloxy > phenylsulfonyloxy > p-tolylsulfonyloxy. Similar treatment of cellobiose12*allegedly gave a mono-( or di-) chloro-mono-(or di-) deoxy-tetra-0-tosyl-“cellobiose.” I n an attempt to obviate chlorination in these two cases, dry powdered magnesium oxide’2Rwas added as intended neutralizer for the hydrogen chloride liberated, but proved ineffective in this role. On the other hand, magnesium oxide completely “prevented ” (see p. 139) both tosylation and chlorination of cellulose1o1 in presence of pyridine (unless the cellulose had been pretreated with a solution of pyridinium chloride in pyridine, in which case the oxide was ineffective). It was suggested that part of the chlorination of cellulose might occur at carbon atom 1 of any glucose residues possessing a free hydroxyl group a t this position. However, Cramer and P u r v e ~ were ’~~ of the opinion that the chlorination observed on tosylating acetone-soluble cellulose acetate in pyridine takes place a t carbon atom 6. As regards sulfonylation of polyvinyl alcohol, the rates of the foregoing three kinds of side-reaction decrease127 in the following order: (1) chlorination by reaction of sulfonyloxy groups with pyridinium chloride; (2) formation of pyridinium quaternary salts; and (3) intramolecular etherification by reaction of sulfonate groups with alcoholic groups. Judging from the general results obtained, the same order apparently holds true in the carbohydrate field, although no precise studies have yet been made. Another possible side-reaction, for which the sugar chemist should be on the alert, is double-bond formation. This might arise from interaction of a n active hydrogen atom with a vicinal sulfonyloxy group (as with a halogen atom), particularly on heating with a tertiary nitrogenous b a s e as in the dehydration of borneol to camphene, and of menthol t o A3-menthene, by action of diethylaniline on the respective p-toluenesulfon(126) (127) (128) (129)
A. L. Bernoulli and H. Stauffer, Helv. Chim.A d a , 23, 615 (1940). D. D. Reynolds and W. 0. Kenyon, J. Am. Chern. Soc., 72, 1584 (1950). A. L. Bernoulli and H. Stauffer, Helv. Chim.Ada, 23, 627 (1940). F. B. Cramer and C. B. Purves, J. Am. Chem. Soc., 61, 3458 (1939).
127
SULFONIC E S T E R S O F CARBOHYDRATES
ates.2s*1soI n this category is the formation95 of 1,3-pentadiene by the
action of beneenesulfonyl chloride on 2,4-pentanediol in pyridine under reflux. The reaction is likely to be encountered when sulfonylation of the non-terminal deoxy-sugars and their acyclic forms receives intensive study. Yet a further possibility involves double-bond formation from suitably activated, vicinal sulfonyloxy groups, 1 3 1 perhaps via an unstable, vicinal dichloro-dideoxy derivative, as follows : I ~-----,
HC;OTs j 1: I H? [o-‘h;
- p:j -
I HCI1
I
Such a transformation is most likely to occur with acyclic sugars, sugar alcohols, sugar acids, and their derivatives (or, for example, between carbon atoms 5 and 6 of 5,6-di-O-sulfonyl-aldohesofuranosederivatives), and may have taken place to some extent, without having been recognized, during prolonged sulfonylations in presence of pyridine, particularly in those conducted above room temperature. In view of the resemblance in reactivity of sulfonyloxy groups to that of Lalogen substituents, formation of an intermediate di-halogeno derivative may, in some cases, not even be a necessary step. e. Practical Details of Sulfonylation in Pyridine.-Despite the possibility that one or more of the above side-reactions may be encountered, more sulfonylations of carbohydrates have been performed with pyridine than with any other base as “neutralizer.” Some of the practical details of this procedure will, therefore, now receive attention. As a rule, the first requisites are to know (a) how marly primary and how many secondary hydroxyl groups the hydroxylic compound possesses; and (b) how many of these groups are to be sulfonylated. Relative Reactivity of Hydroxyt Groups.-The question early arose as to whether, in a polyhydroxy compound having bot,h a primary and several secondary hydroxyl groups, there is (with respect to a given (130) Cf.,I<. Freudcnberg, H. Fikcntscher, and M. Harder, Ann., 441, 157 (1925); E. Rothstein, J . Chem. Soc., 309 (1937); M. L. Dhar, E. D. Hughes, C. K. Ingold, A. M. M. Mandour, G. A. Maw, and L. I. Woolf, ibid., 2093 (1948); F. G. Bordwell and G . D. Cooper, J . Am. Chem. Soc., 74, 1058 (1952). (131) R. S. Tipson and Mary A. Clapp, i n E. R. Weidlein, “Current Scientific Researches in Mellon Institute,” (1951), p. 10, Pittsburgh, Pa.
128
R. STUART TIPSON
sulfonyl chloride) any difference in reactivity (a) between this primary group and the secondary groups; and (b) between one secondary hydroxyl group and another. Now, in 1924, Ohle'32had discovered that treatment of 1 molar proportion of 1,2-O-isopropylidene-~-g~ucofuranose in pyridine with 1 molar proportion of benzoyl chloride (slowly added dropwise, with stirring) gave rise to the 6-0-benxoyl derivative. Hence, in this compound, the primary hydroxyl group (at carbon atom 6) is more reactive than the secondary hydroxyl groups (at carbon atoms 3 and 5). I n the following year, a similar procedure was successfully applied73for the preparation of the corresponding 6-0-tosyl derivative: a solution of 1 molar proportion of p-toluenesulfonyl chloride in dry chloroform was added dropwise to a stirred pyridine solution of the 1,2-0-isopropylideneD-glucofuranose, and the mixture was kept overnight at room temperature. Similarly, 1,2-0-isopropylidene-3-0-tosy~-o-glucofuranose(pre-
-
HO~H HA0 HAOH LH20H
I
-I
HO~H HA0 HbOH (!3H20Ts
pared by removal of the 5,6-O-isopropylidene group from 1,2 :5,6-di-Oisopropylidene-3-0-tosyl-~-g~ucofuranose; see p. 143) gave73the 3,6-di-0tosyl derivative. I n neither of these acylations was cooling applied, but, in many of the unimolar acylations subsequently reported, cooling during admixture of the reactants has been deemed advisable as a result of the experience gained in unimolar phosphorylation (with phosphorus oxychloride in pyridine) of the primary hydroxyl group of related compounds. Cooling retards reaction sufficiently that a greater proportion of the primary hydroxyl groups are targets for the acylating agent, before some of i t is used up by the less reactive, secondary hydroxyl groups. Thus, in the preparation of 1,2-~-~sopropy~~dene-5-~-tosy~-~-xy~ofuranose,'~~ a sohin dry pyridine was cooled in tion of 1,2-0-isopropylideiie-~-xylofuranose ice and, with mechanical stirring and continued cooling, a solution of p-toluenesulfonyl chloride (1.1 molar proportions) in dry chloroform was added dropwise during 20 minutes. After a further 60 minutes at O", (132) H. Ohle, Ber., 67, 403 (1924). (133) P. A. Levene and A. L. Raymond, J . Bid. Chem., 102, 317 (1933).
SULFONIC ESTERS OF CARBOHYDRATE6
129
the mixture was kept overnight a t room temperature; the yield was 61 % of the theoretical. A useful application of unimolar tosylation is in the preparation of 5-O-sulfonyl-aldopentose dialkyl mercaptals which, having the hydroxyl group on carbon atom 5 blocked, are an excellent source134 for aldopentofuranose derivatives.
0
80
I60 240 Time, minutes
320
FIG.2.-Acti0n'~~ of Tosyl Chloride (8 Moles) on 1,2:3,4-Di-O-isopropylidene-~galactose (1 Mole) in Pyridine a t 23 k 2". (Taken from R. C. Hockett and M. L. Downing, J . Am. Chern. Sac., 64,2463 (1942).)
00
I 60 Time, hours
240
I 320
FIG.3 . - A ~ t i o n ' ~ ~of Tosyl Chloride (8 Moles) on 1,2:5,6-Di-O-isopropylidene-~glucose (1 Mole) in Pyridine at 23 k 2". (Taken from R. C. Hockrt,t and h f . L. Downing, J. Auz. Chem. Soc., 64,2463 (1942).)
Despite the immediate application of unimolar sulfonylation for the preparation of many w-sulfonic esters of sugar derivatives, a kinetic study of the reaction was not made until 1942; Hockett and Downingl36 then found that, with p-toluenesulfonyl chloride-pyridine a t 23" rl: 2", the time t o half-esterification for a mole of 1,2 :3,4-di-O-isopropylidene-~galactose (with a primary hydroxyl group) is 0.272 hours (see Fig. 2 ) , whereas for 1,2:5,6-di-O-isopropylidene-~-glucose (with a secondary hydroxyl group) it is 20.2 hours (see Fig. 3). T h a t is, after about 120 minutes, nearly all of the compound with the free primary hydroxyl group (134) P. A. Levene and J. Compton, J . Biol. Chem., 116, 189 (1936). (135) R.C. Hockett and M. L. Downing, J . Am. Chem. Soc., 64, 2463 (1942).
130
R. STUART TIPSON
had been tosylated, but about 120 hours was required for tosylation of most of the material with the secondary hydroxyl group. [2,3:4,6-Di-Oisopropylidene-L-sorbose (having a primary hydroxyl group) showed a time (to half-esterification) of 0.583 hours, and required about 240 minutes for almost complete tosylation; as will be mentioned later (see p. 190), the primary hydroxyl group a t carbon atom 1 of ketoses differs in reactivity from the o-primary hydroxyl group of aldoses.] The greater reactivity, towards p-toluenesulfonyl chloride, of the primary hydroxyl group of D-galactopyranose, as compared with that of a secondary hydroxyl group a t carbon atom 3 of D-glucofuranose, was found t o be of about the same order as towards triphenylmethyl (trityl) ch10ride.l~~ These results, though extremely valuable, might have been even more informative had appropriate derivatives of the same sugar been employed for the comparisons of reactivity. For ' I heterogeneous" tosylation of c e l l ~ l o s e , 'in ~ ~ which differentiation between the secondary hydroxyl groups of a glucose residue was not feasible, the rate of esterification of the primary hydroxpl groups was found t o be 5.8 times that of the secondary hydroxyl groups (averaged). The second discovery was that secondary hydroxyl groups may differ noticeably, inter se, in reactivity. Thus, again considering l12-O-is0propylidene-D-glucofuranose, addition of a second, and even of a third, molar proportion of p-toluenesulfonyl chloride, with reaction permitted during 3 days a t ,36", gives73the 5,B-di-0-tosyl derivative, a d m i ~ e d ' ~ ~ , ~ ~ ~
A
II OTs
A
€I OTs &H20Ts
with some of the 3,5,6-tri-O-t0syl~~~ derivative.
Hence, in this instance,
(136) R. C. Hockett, H. G. Fletcher, Jr., and J. B. Ames, J . Am. Chem. SOC.,63, 2516 (1941). B. Helferich, Advances in Carbohydrale Chem., 3, 79 (1948). (137) E. Heuser, M. Heath, and W. M. Shockley, J . Am. Chem. SOC.,72, 670 (1950). (138) H. Ohle, H. Erlbach, and K. Vogl, Ber., 61, 1875 (1928). (139) R. Montgomery and L. F. Wiggins, J. Chem. SOC.,390 (1946). (140) H. Ohle and H. Wilcke, Bey., 71, 2316 (1938).
SULFONIC ESTERS O F CARBOHYDRATES
131
the secondary hydroxyl group a t carbon atom 5 is more reactive than th a t at carbon atom 3. Knowing this, it then became feasible t o prepare, for example, 6-0-benzoyl- 1,2-0-isopr opylidene-5-0-t osyl-D-glucofuranose, b y unimolar tosylation of the corresponding 6-benzoate1 which had itself been formed by unimolar henzoylation. (Dimolar tosylation gave73the 6-0-benzoyl-3,5-di-0-tosyl derivative.) HCO, I *,CH3
Ho&H
I
HCO
I
HCOH
I
CH~OBZ
~1
H&O/
~
c
I HOCH I
'CHs
1x0___
I
HCOTs
I
CHZOBZ
I n aldohexopyranose derivatives, the hydroxyl group a t carbon atom 5 is, of course, engaged by the oxygen ring, and the secondary hydroxyl group at carbon atom 2 of glucose is found to be more reactive than those a t positions 3 and 4. Thus, dimolar benzoylation of methyl a-D-glucopyranoside yields '' the 2,6-di-O-benzoyl derivative. Similarly, dimolar tosylation of anhydrous a-D-glucose in pyrjdine, followed by acetylation, affordst4? 1,3,4-tri-0-acetyl-2,6-di-0-tosyl-a-~-glucose (in 20% yield) together with a little of its p-anomer and some 1,2,3,4-tetra-0-acetyl-6-0tosyl-0-D-glucose. In the same way, methyl a-D-galactopyranoside is said to give113a separable mixture of the (i-0-tosyl and the 2,6-di-O-t0syI~~~ derivatives; the latter constituent may also be prepared143by unimolar tosylation of the former. Likewise, unimolar tosylation of methyl
HCOH HOCH
HCO
I
CHzO (141) T. Lieser and R. Schweitzer, Ann., 619, 271 (1035). (142) E. Hnrdegger, R . M. Montavon, and 0. Jucker, Helv. Chim. Ada, 31, 1863
(1948). (143) W. N . Haworth, J. Jackson, and F. Smith, J . Chern. Soc., G20 (1940). (144) Mrs. Prem A. Rao and F. Smith, J . ('heni. SOC.,229 (1944).
132
R. STUART TIPSON
4,6-0-benzylidene-a-~-glucopyranosideafford^'^^,'^^ the 2-0-tosyl derivative plus some of the 2,3-di-O-tosyl compound (separable146by chromatography). Again, experiments on the “homogeneous” tosylation of partially ethylated cellulose indicated147that the rate-order constants for esterification of the hydroxyl groups a t positions 6, 2, and 3 are approximately as 15:2.3 :0.07; in a chain, the hydroxyl groups a t positions 4 of all but the terminal, glucosidically-bound glucose residue are, of course, engaged in chain formation. For tosylation of acetone-soluble, partially acetylated cellulose, the rates were found to be‘48in the approximate ratio of 23.4 :2.16 :0.106. I n all the foregoing examples, the decreasing order of reactivity of secondary hydroxyl groups of D-glucopyranose derivatives is: position 6 > position 2 > position 3, yet it has been claimed’49that tosylation of 7’- (4,6-0-benzylidene-P-~-glucopyranosyl) theophylline gives a separable mixture of the 2,3-di-O-tosyl derivative with the 3-0-tosyl derivative. In contrast to that of glucose, the hydroxyl group a t position 3 of D-galactopyranose derivatives is more reactive than that at position 2. Thus, t o s y l a t i ~ nof~ ~methyl ~ 4,6-O-benzylidene-t(or -P)-D-galactoside ~ - ~a ~ ~ gives a preponderance of the 3-0-tosyl derivative a d r n i ~ e d l ~with little of the 2-0-tosyl and 2,3-di-O-tosyl derivatives. Relative Reactivity of Sulfonyl Chlorides; Steric Hindrance.-In sulfonylation of polyvinyl the degree of sulfonylation achieved under specified conditions is a function of the molecular size of the sulfonyl radical introduced, in qualitative agreement with steric considerations. Of those sulfonyl chlorides examined, the fastest and most complete sulfonylation resulted with methanesulfonyl chloride, followed by benzenesulfonyl and p-toluenesulfonyl chlorides; the least reactive was 8-naphthalenesulfonyl chloride. I n this connection, it is claimed’64 that cannot be tosylmethyl 2,3-di-0-acetyl-6-0-trityl-/3-~-galactopyranoside ated, although it is readily acetylated or mesylated. This behavior was attributed t o steric hindrance by the trityl group (Tr) t o entrance of the tosyl group, but not to entrance of the (smaller) acetyl and mesyl groups. In support of this concept, it is that the 4,6-di-O-tosyl deriva(145) (146) (147) (148) (149) (150) (151) (152) (153) (154)
G. J. Robertson and C. F. Griffith, J. Chem. SOC.,1193 (1935). H. R. Bolliger and D. A. Prins, Helu. Chim. Acta, 28, 465 (1945). J. F. Mahoney and C. B. Purves, J. Am. Chem. SOC.,64, 9 (1942). T. S. Gardner and C. B. Purves, J. Am. Chem. Soc., 64, 1539 (1942). W. E. Harvey, J . J. Michalski, and A. R. Todd, J . Chem. SOC.,2271 (1951). E. Sorkin and T. Reichstein, Helu. Chim. Acta, 28, 1 (1945). M. Gyr and T. Reiohstein, Helv. Chim. Acta, 28, 226 (1945). A. C. Maehly and T. Reichstein, Helv. Chim. Acta, 30, 496 (1947). H. Huber and T. Reichstein, Helv. Chim. Acta, 31, 1645 (1948). A. Miiller, Maria Mbrics, and G. Verner, Ber., 72, 745 (1939).
133
SULFONIC ESTERS OF CARBOHYDRATES
n
-I
I
HLOAc AcOAH 4
TsOAH H 0 -
tive can be prepared; and no difficulty had been reported in preparing156
r-
7-
HCOCH3
bI
H 0--
CHlOTr
1
H A 0 1
t:HrOTr
the 4-0-tosyl derivative of methyl 2,3-di-O-benzoyl-6-0-trityl-a-~-g2ucopyranoside, in which the 3-0-benzoyl group is sterically remote from the 4-0-tosyl group. A related example is encountered on t o ~ y l a t i n g ' ~ ~ 1,6-anhydro-D-glycero+?-D-pdo-heptopyrslnose (formerly called "D-gZUCOD-gulo-heptosan<1,5>p<1,6> "): instead of the expected 2,3,4,7-tetra0-tosyl derivative, there is obtained the 2,3,7-tri-O-t osyl compound. This is attributed to the spatial proximity of the primary hydroxyl group a t Carbon atom 7 (which is tosylated .first) t o that at carbon atom 4. Entrance of the tosyl group at carbon 7 hinders tosylation at carbon 4. A steric factor may also account for the extreme difficulty ex~erienced'~' in attempting t o tosylate 3,4-0-isopropylidene-l,~-di-0-phenyl-~-mannitol; treatment during 8 hours at 120-130" was found necessary for formation of the 2,5-di-O-tosyl derivative. Optimal Conditions for Sulfony1ation.- In attempting t o decide the optimal conditions to be employed for any projected sulfonylation in the presence of pyridine, tl number of factors should receive attention. We may first consider the question of the proporiion of sulfonyl chloride to be added, reIative to the proportion of carbohydrate derivative t o be esteri(155) J. W.H.Oldhain and G. J. Robertson, J. Cheiri. SOC.,085 (1935). (156) Edna M. Montgomery, N. K. Richtinyer, and C. S. Hudson, J . Am. Chem. Soc., 66, 1848 (1943). (157) G. P. McSweeney, L. F. Wiggins, and D. J . C. Wood, J . Chem. Sac., 37 (1952).
134
R. STUART TIPSON
fied. If the latter compound has only one free hydroxyl group, an excess of sulfonyl chloride as great as 50% has been employed with excellent results, as in the preparation of 1,2 :5,6-di-O-isopropylidene-3-0tosyl-D-glucoselR (yield, 85 % of the theoretical) and of 1,2:3,4-di-O-isopropylidene-6-O-tosyl-~-ga~actose~~~ (yield, 95 % of the theoretical). For sulfonylation of all free hydroxyl groups of polyhydroxy compounds, an even greater excess has sometimes been employed. However, a 10% excess is probably ample in most instances, even if the sulfonyl chloride hm not been prepurified, provided that it contains only traces of free sulfonic acid or of hydrogen chloride. Where all the free hydroxyl groups are to be esterified, the order of admixing the reagents is usually immaterial, and, with appropriate cooling, portionwise addition is unnecessary. Even in the special cases of unimolar and dimolar sulfonylations, already discussed, a 10 % excess (over the corresponding calculated amount) is customarily employed nowadays. Little attention has been paid to the proportion of pyridine to be used. In nearly all experiments, sufficient has been added, not only to neutralize all of the hydrogen chloride which would be liberated if the sulfonylation proceeded to completion (equation (2)), but also t o dissolve all of the starting materials. This usually entails the use of considerably m o r e than one mole of pyridine per mole of sulfonyl chloride; even in heterogenous sulfonylations (e.g., of cellulose*37)use of a large excess of pyridine is customary. However, Freudenberg and observed that, although 2,4-dinitrophenol treated with ptoluenesulfonyl chloride in excess pyridine at 40' gives the pyridinium salt, the ester results if only one molar proportion of pyridine (dissolved in dry chloroform) is used, even though the reaction be performed a t 90". (The latter treatment is tantamount to employing the pyridine-sulfonyl chloride 1: l - a d d ~ c t . ' ~ ~ ) Moreover, in a study of the esterification of certain unstable, secondary alcohols, Mills16oconcluded that poor yields were probably occasioned by dehydration or rearrangement catalyzed by the acidic pyridinium ion. For esterifications in which there is likelihood either that such changes or that an exchange reaction with chloride ion may occur, he advocated the use of only a 10% excess (1.1 mole) of pyridine per mole of sulfonyl chloride (per 1 mole of a monohydric alcohol), in an ice-cold reaction medium (e.g., dry benzene-petroleum ether) which almost completely precipitates pyridinium chloride as fast as it is formed and which suppresses ionization of the trace remaining dissolved. Such ideal conditions may be difficult or impossible t o devise for sulfonylation of many (158) K. Freudenberg and H. Hess, Ann., 448, 121 (1926). (159) G. L. Schwartz and W. M. Dehn, J . Am. Chem. Soc., 39, 2444 (1917). (160) J. A. Mills, J . Chem. Soc., 2332 (1951).
SULFONIC ESTERS OF CARBOHYDRATES
135
carbohydrate derivatives, but there seems to be no doubt that a suitable, inert d i l ~ e n t ~ should ~ ~ ~ 0be~ added ~ ~ ' (see p. 116) whenever feasible and that the weight of pyridine employed should exceed the theoretical amount by as small a proportion as is consistent$with initial dissolution of at least part of the reactants (except, perhaps, in 1"heterogeneous" sulfonylations). Thus, 1,3-di-O-tosyl-glyceritol was obtained74 from ' yield by using only 1.25 moles of pyridine per 0.55 mole of glycerol in 71% p-toluenesulfonyl chloride; a 93 % yield of the tri-ester resulted with use of 0.75 mole of pyridine per 0.36 mole of p-toluenesulfonyl chloride. A further, rather obvious refinement, which may in many instances prove beneficial, consists in dropwise addition of the pyridine (rather than of the sulfonyl chloride or a solution thereof) ;this technique was successfully employed74by Drahowzal and Klamann. As regards the temperature at which a sulfonylation in pyridine should be performed, reference has already been made to the fact that the rate of each of the possible side-reactions is much lower if the esterification is performed at (or below) room temperature than it is if higher temperatures are used. During the early years of study of the reaction, the effect 4 0 °,1 4 ~1 b ~7 3 of various temperatures (for example, 30°,16162 37°,73*163 60°,122~164 or the boiling t e m p e r a t ~ r e 114 ' ~ of the chloroform-containing reaction mixture) was rather haphazardly examined; it was found that the yield of desired product was not necessarily impaired by use of the higher temperatures. If the compound to be sulfonylated possesses hydroxyl groups of low reactivity, and if the resultant sulfonic ester is not very susceptible t o any of the side-reactions previously mentioned (see p. 117), use of a higher temperature may actually be advantageous. However, as a rule, it is advisable to perform the reaction at room t e m p e r a t ~ r e ~ ~ * ~ ~ ? ' ~ or166at 0". Use of the latter, or a lower, temperature is particularly rec~mrnended'~~ for unimolar sulfonylation (see p. 128) of a primary hydroxyl group in a compound also possessing free secondary hydroxyl groups. Finally, there is the matter of how long a time the reaction should be permitted to proceed. Almost complete reaction of a primary hydroxyl group is often achieved in several hours, even at 0", but the secondary hydroxyl groups react more slowly. As judged by the yield of product, (161) Cj., T. Reichstein, Helv. Chim. Acta, 9, 799, 803 (192G); D. T. C. Gillespie,
A. K. Macabeth, and J. A. Mills, J. Chem. SOC.,996 (1948); 0. M. Friedman and A. M. Seligman, J. Am. Chem. SOC.,72, 624 (1950). (162) (163) (164) (165) (166)
E. E'acsu, Ber., 67, 849 (1924). H. OhIe and Ilse Kollcr, Ber., 67, 1566 (1924). W. N. Haworth and C. R. Porter, J. Chem. SOC.,2796 (1829). B. Helferich and W. Klein, Ann., 460, 219 (1926). H. 0. L. Fischer and C. Taube, Ber., 67, 1502 (1924).
136
R. STUART TIPSON
the rate of esterification by means of sulfonyl chlorides in dry pyridine has appeared, in certain cases, t o be lower than that with acetic anhydride or benaoyl chloride in the same solvent; hence, it has often been deemed necessary t o extend the reaction time t o a period of several days,73,117*163 or even weeks,1u5in the hope of ensuring a satisfactory yield. However, since all of the possible kinds of side-reaction are probably preceded by formation of the sulfonic ester, it is improbable that the yield will usually be increased, and often possible th at it may actually be decreased, by using a reaction time much exceeding about 24 hours. Indeed, treatment of methyl 3,4-O-ethylidene-/?-~-arabinosidewith a 50 54 excess of p-toluenesulfonyl chloride in pyridine during SO miiwtes a t room temperature reputedly gavel6’ an 86 % yield of its 2-0-tosyl derivative; reaction of 3,B-anhydro-4,5-0-isopropylidene-~-mannitol with methanesulfonyl cbhloride (2.5 molar equivalents) during 2.6 hours at room temperature affordedI6*a satisfactory yield of its ll2-di-O-mesy1 derivative; for longer and mesylation of methyl 3,4-0-isopropylidene-a-~-galactoside than 5 hours (with 2.3 molar equivalents of methanesulfonyl chloride in pyridine) was foundi69to be definitely inadvisable owing t o separation of unidentified, tarry by-products. I n all these examples, sulfonylation of secondary hydroxyl groups was satisfactorily accomplished ; a large proportion of any primary hydroxyl groups of a sugar derivative would certainly have been sulfonylat,ed under the same conditions. Thus, dimolar tosylatiori of 2,4-0-methylene-~-glucitol during 4 hours at 25” gave1Iua 69% yield of the 1,B-di-0-tosyl derivative. With the possible exception of Hess and Stenael’s work, l1’ no really comprehensive study of the effect of reaction time on yield of sulfonic esters of polyhydric, sugar derivatives has been encountered in the literature. As a result of these considerations, T i p ~ o n was ? ~ able t o devise a simple, fairly general method for sulfonylation of monohydric alcohols (and phenols) in pyridine which has since been widely and successfully used; it is applicable t o sulfonylation of many carbohydrate derivatives. Of the various precautions advocated in the literature as being advisable (including stirring, portionwise addition of sulfonyl chloride, and extensive prepurification of the latter), only two were found to be really necessary in all cases. First, since sulfonyl chlorides are rapidly hydrolyzed by slightly moist pyridine, it is essential that both the pyridine and the (167) J. Honeyman, J. Chem. Soc., 990 (194G). (168) A. B. Foster and W. G. Overend, J . Chem. Soc., 680 (1951). (169) A. B. Foster, W. G. Overend, M. Stacey, and L. F. Wiggins, J . Chem. Soc., 2542 (1949). (170) A. T. New, R. M. Hann, and C. S. Hudson, J . Am. Chem. SOC.,66, 1901 (1944).
SULFONIC ESTERS O F CARBOHYDRATES
137
hydroxylic compound t o be sulfonylated be dry, and that the reaction be performed with rigorous exclusion of atmospheric moisture. (Except for formation of a loose a d d ~ c t , p-tolueiiesulfonyl ’~~ chloride, for example, ~~ has no effect on dry pyridine, and may even be r e ~ r y s t a l l i z e dtherefrom after boiling.) Secondly, with alcohols yielding sulfonic esters susceptible to one or more of the possible side-reactions, the temperature of the reaction mixture should be kept at, or somewhat below, 0’; in other cases, room temperature proved satisfactory. For convenience in judging rates of sulfonylation by observing deposition of pyridinium chloride, the ratio of p-toluenesulfonyl chloride to pyridine was kept constant a t 25 g. per 100 ml. (although, in view of Mills’ more recent160observations, the proportion of pyridine might well be decreased wherever feasible) ; and a 10% excess of sulfonyl chloride, relative to the alcoholic (or phenolic) groups t o be sulfonylated, was used. With a reaction time of 2 hours under these conditions, substances which had normally undergone chlorination were sulfonylated in high yield without formation of even a trace of chloro derivative; and certain alcohols and phenols which, it had been alleged, could not be tosylated in the presence of pyridine (owing t o rapid formation of their pyridinium salts) readily gave their tosyl esters in high yield by using a reaction time of ca. 15 minutes. In isolating the product, excess sulfonyl chloride is hydrolyzed by slow, portionwise addition of a small volume of water, with cooling and agitation, followed by addition of a larger volume of water. This simple treatment should not be omitted; some workers have poured the reaction mixture directly onto a large volume of ive or into much water (which hydrolyzes sulfonyl chlorides a t a surprisingly low rate), thereby obtaining a crude product contaminated with unhydrolyzed sulfonyl chloride. If the ester does not crystallize out a t this stage, it, is extracted into chloroform and the chloroform extract is freed from pyridine (by washing with cold, dilute sulfuric acid, and water), and from acids (by washing with aqueous sodium bicarbonate solution, and water) ; the resulting chloroform solution is then dried with anhydrous sodium sulfate, filtered, and the filtrate evaporated to dryness under diminished pressure. Separation and purification procedures are discussed on p. 140. In unimolar or dimolar sulfonylations in which the product still has free hydroxyl groups (and is usually a mixture of compounds), crystallization may not occur. Very often, separation may be accomplished after the mixture has been acetylated. A useful procedure is t o add acetic anhydride to the sulfonylation m i ~ t u r e ~ ~ , (after 1 7 ~ ~sulfonylation ~7~ is judged to have proceeded to completion, but before addition of water) (171) J. Compton, J . Am. C h e m SOC.,60, 395 (1938). (172) J . Compton, J. Am. Chem. Soc., 60, 1203 (1938).
138
R. STUART TIPSON
and then permit sufficient time to elapse for acetylation to occur, before ~ ~ ~ ~ ~preferable ~~ water is added. I n some cases, b e n ~ o y l a t i o nproves because of the crystallizability of the resulting benaoates. f. Re-evaluation of Literature Reports.-Many “irregular ” sulfonylations reported in the literature now become understandable, and some require re-examination in the light of our accumulated knowledge. The following are a few examples, but many more are t o be encountered, scattered through the literature. It was found122that 2,3:5,6-di-0-isopropylidene-~-mannose reacts with p-toluenesulfonyl chloride in pyridine, but the only product isolated was the corresponding mannofuranosylpyridinium p-toluenesulfonate. On the other hand, when 2 moles of the sodium salt of 2,3:5,6-di-O-isopropylidene-D-mannose, dissolved in dry petroleum ether, were treated with one mole of p-toluenesulfonyl chloride, there apparently resulted the nonreducing-disaccharide derivative, 2,3:5,6-di-O-isopropylidene-~mannofuranosyl 2,3:5,6-di-0-isopropylidene-~-mannofuranoside (a compound later prepared121by condensation of 2,3:5,6-di-O-isopropylidene-~mannosyl chloride with 2,3:5,6-di-0-isopropylidene-~-mannose).Presumably, the following reactions had taken place (Ip = isopropylidene) :
+ NaCl HbO
I
>IP CH2O
HA0
\
CHzO
CHzO
HA0 CHzO
HA0
CH2O
HA0
\
CHzO
(173) W. T. Haskins, R. M. Hann, and C. S. Hudson, J . Am. Chem. Soc., 68, 628 (1946). (174) R. C. Hockett, Maryalice Conley, M. Yusem, and R. I. Mason, J . Am. Chem. Soc., 68, 922 (1946).
SULFONIC ESTERS OF CARBOHYDRATES
139
A further attempt to ascertain the reason for the poor yield of 1,2-0isopropylidene-5,6-di-0-tosyl-~-glucose resulting73on tosylation of either 1,2-O-isopropylidene-~-glucose or its 6-0-tosyl derivative might be advisable. A supposed steric factor was held responsible?o for the failure to obtain more than a 50% yield of crystalline methyl 4,6-di-O-phenylsulfonyl-2,3-di-O-methyl-fl-~-glucoside(on treating methyl 2,3-di-0methyl-fl-D-glucopyranoside with benzenesulfonyl chloride in pyridine, during several days a t room temperature) ; this behavior was attributed t o difficulty in sulfonylating the secondary hydroxyl group at carbon atom 4 after the primary hydroxyl group at carbon atom 6 had been sulfonylated. However, the same workers obtained175a 60% yield of the crystalline 3,4,6-tri-0-tosyl derivative of methyl 2-O-methyl-fl-~-glucopyranoside; this suggests that steric hindrance is not here responsible for the observed results. Again, Hess and LjubitschlOb remarked that a combination of the phenomena of sulfonylation, chlorination, and quaternization failed to provide a coherent explanation for their observations on the prolonged treatment of cellulose with tosyl chloride in pyridine. Re-examination thereof, with special attention to the possible formation of anhydro rings (and, perhaps, of double bonds), is indicated. 3. Other Methods for Sulfonylation
a. Use of the Sulfonic Anhydride.-It is possible that a solution to some of the foregoing difficulties engendered by side-reactions may, in certain cases, be found in the use of the pyridine adduct of the appropriate sulfonic anhydride, for sulfonylation i n an inert solvent. Thus, benzenesulfonic anhydride,17E~177 (CsHjS02)20, gives an a d d ~ c t , 'probably ~~ 1-phenylsulfonyl-pyridinium benzenesulfonate, which reacts with phenol in dry benzene to yield phenyl benzenesulfonate. However, it appears that the only fruitful applications, to date, of sulfoiiic anhydrides in the carbohydrate field consist in the mesylationZ4of methyl a-D-glucOpyranoside (with methanesulfonic anhydride in pyridine) and the tosylation of (alkali-) cellulose48fwith p-toluenesulfonic anhydride.176 Some doubts exist, however, as to the validity of the latter claim, since later workers128observed absolutely no reaction, even after treatment for 24 days at room temperature. (175) J. W. H. Oldham and Jean K. Rutherford, J . Am. Chem. Soc., 64, 1086 (1932). (176) H. Meyer and K. Schlegl, Monatsh., 34, 561 (1913). (177) F. Fichtcr and E. Stocker, Helv. Chin%..4cta, 7, 1064 (1924). (178) L. Field, J . Am. Chem. Soc., 74, 394 (1952).
140
R. STUART TIPSON
b. Use of Anhydro Derivatives of Sugar Alcohols.-Treatment of 1,2anhydro-3-deoxyglyceritol(propylene oxide) in dry ether with one molar proportion of p-toluenesulfonic acid (added portionwise, and the solution kept overnight at room temperature) aff o r d ~ ~ ~ 2-0-tosyl-3-deoxyt'7~ D,L(?)-glyceritol (2-tosyloxypropyl alcohol) plus 1-0-tosyl-3-deoxy-~,~glyceritol (l-tosyloxy-propan-2-ol), which are separable after beneoylation. An even more interesting reaction, with potentialities which should be further explored, is that which occurs when 1,3-anhydro-2,4-O-methyleneD,L-xylitol is treatedIs0 with p-toluenesulfonyl chloride in pyridine (during 3 days a t room temperature and then 8 hours a t 70"). The expected 5-0-tosyl derivative is accompanied by a monochloro-monodeoxy-2,4-0methylene-di-0-tosyl-D1L-xylitol formed by opening of the anhydro-ring.
111. PHYSICAL PROPERTIES AND CHEMICAL STABILITY I n purifying, and assessing the purity of, sulfonic esters of sugars, a knowledge of some of their general physical properties is helpful. 1. Some Physical Properties of Sulfonic Esters Many sulfonic esters of monosaccharides and their derivatives crystallize with comparative ease, thereby affording a means of purification. As a consequence, little attention has been paid t o appliccLtion of other methods of purification. A few sulfonic esters of sugars have been purified chromatographically. 148,1b1- 3 18' However, the p-toluenesulfonates of a number of simple monohydric alcohols may be distilled29In2without decomposit,ion, a t a pressure of 0.1 mm. Hg. Similarly, 3,3-dimethyl-3-deoxy-2-O-tosyl-~(?)-glycerotetrono- l14-lactone (" d ( - )-a-hydroxy-p,p-dimethyl--pbutyrolactone p-toluenesulfonate") distils'83 a t 205"/0.5 mm., and methyl 3,4-diO-acetyl-2-O-methyl-6-O-tosyl-cu-~-altroside may be distil led'^^ a t 10 mm. Hence, this method may sometimes prove useful in separation and purification. Certainly, sublimation md er high vacuum186 should prove applicable in many instances. As a rule, crystalline sulfonic esters of monosaccharides and their derivatives are colorless, and exhibit sharp melting points. Many, of (179) G. A. Haggis and L. N. Owen, J . Chem. Soc., 2250 (1950). (180) R. M. Hann, N. K. Richtmyer, H. W. Diehl, and C. S. Hudson, J . Am. Chem. SOC., 72, 561 (1950). (181) M. Gut and D. A. Prins, Ilelu. Chim. Acta, 30, 1223 (1947). (182) C. W. Tasker and C. B. I'urves, J . A m . Chem. SOC.,71, 1017 (1949). (183) H. Bretschneider and H. Haas, Monatsh., 81, 945 (1950). (184) F. G. Young, Jr., and R. C. Elderfield, J. Org. Chem., 7, 241 (1942). (185) R. S.Tipson, "Sublimation," in I ' Technique of Organic Chemistry," Interscience Publishers, Inc., New York, N. Y., 1951, IV, pp. 603-645.
SULFONIC ESTERS O F CARBOHYDRATES
141
course, exhibit optical rotatory power in solution. For tosyl esters which melt without decomposition, the molar refraction of the -0S02- group has been foundln2to be 10.5 k 0.35. The ultraviolet and infrared absorption spectra are often invaluable
WAVELENGTH IN MILLIMICRONS F I G . 4.-Ultraviolet Absorption of Methyl p-Toluenesulfonate (in Hexane). (Taken from A. L. Bernoulli and H. Stauffer, Helv. C h h . Acta, 2S, 615 (1940).)
for rapidly determining the relative purity of routine preparations of a sulfonic ester when once the spectra of a specially-purified sample have been recorded. Sometimes, they also serve t o reveal previously unsuspected structural details. To provide examples of the contributions of the tosyloxy group to such spectra, the ultraviolet126and infraredls6 absorption spectra of methyl p-toluenesulfonate are shown in Figs. 4 (186) K. C. Schreiber, Anal. Chem., 21, 1168 (1919).
142
R. STUART TIPSON
and 5. The contributions of the tosyloxy group to the infrared spectra of the tosyl esters of two sugar alcohols have re~ently'~' been reported. WAVE LENGTH, MICRONS
1300 WAVE NUMBERS, CM.-'
1400
1500
FIQ. 5.-Infrared Absorption of Methyl p-Toluenesulfonate (in Carbon Tetrachloride). (Taken from K. C. Schreiber, Anal. Chem., 21, 1168 (1949).)
The dipole moments of several p-toluenesulfonates have been determined. 126 2. Chemical Stability of Sdfonyl or Sulfonyloxy Groups
In order that full advantage may be taken of the chemical transformations that sulfonic eaters of sugars can undergo, a knowledge of the conditions under which they are chemically unreactive is essential. In this connection, specific chemical reagents and the physical conditions of their application must both receive consideration. First, however, the special case of 1-0-sulfonyl-aldoses will be mentioned. A sulfonyloxy group attached at the reducing or glycosidic carbon atom of a ring-form of an aldose shows a reactivity somewhat comparable t o that of a halogen atom at this position. Thus, tetra-0acetyl-1-0-tosyl-p-D-glucopyranosereadily decomposes33on attempted recrystallization, and the corresponding 1-0-mesyl derivative24yields I
MsOCH
h
H OAc ACOAH
A
H OAc
c!
H 0-
AH*OAc
bH,OAc
methyl tetra-O-acetyl-&D-glucopyranosideon boiling a solution in abso(187) R. S. Tipson, J . Am. Chem. Soc., 74, 1354 (1952).
SULFONIC ESTERS OF CARBOHYDRATES
143
lute methanol, in the presence of calcium carbonate, for several hours (presumably via intermediate formation of an ortho ester1Y8). In contrast, sulfonyl groups introduced onto the alcoholic hydroxyl groups of carbohydrates are bound much more tenaciously and are stable to the influence of a wide variety of reagents. No case has been encountered in which a sulfonyl group “migrates.” As a rule, the more readily is the sulfonyl group introduced, the more readily is the sulfonyloxy group removed; that is t o say, a secondary sulfonyloxy group is usually more stable towards a given chemical reagent than is a primary sulfonyloxy group. However, exceptions to this generalization (possibly attributable in some cases to stereochemical effects) may be encountered. The following are examples of the conditions under which true sulfonic esters are normally unaffected by common reagents, together with exceptions which have been reported. a. Various Acidic Environments.-A sulfonyloxy group is usually stable to aqueous organic acids and to dilute, aqueous mineral acids. Thus, in if a 2 % solution of 1,2:5,6-di-O-isopropylidene-3-0-tosyl-~-glucose glacial acetic acid plus water (3 :1, by vol.) is kept73at room temperature results : during 48 hours, 1,2-0-isopropy~idene-3-O-tosy~-~-gIucofuranose
A
H 0-
Ib
HA 0
HkHLOH
LH20H
CHZO
(In a quicker procedure, the same product was obtainedlR9from a 20% solution in aqueous acetic acid of the same strength, during 4 hours at 50”. Very similar conditions were employedlgOfor preparation of the corresponding 3-0-meeyl derivative.) Likewise, treatment of 1,2 :3,5-diO-isopropy~idene-6-~-t-tosyl-~-g~ucose (10 % solution in 80 % acetic acid) at room temperature during 96 hours giveslgl 1,2-0-isopropylidene-6-0tosyl-D-glucofuranose (without loss of the primary tosyloxy group) ; if the latter compound is now dissolved1Y1 in 70% acetic acid (to give a (188) H. S. Isbell and Harriet L. Frush, J. Research Natl. Bur. Standards, 45, 161 (1949). (189) L. von Varghe, Bw., 69,2098 (1936). (190) B. Helferich, H. Dressler, and R. Griebel, J. prakt. Chem., 163, 285 (1939).
(191) H . Ohle and L. von Vargha, Ber., 62, 2425 (1929).
144
R. STUART TIPSON
10% solution) and kept a t 37” for 144 hours, 6-0-tosy~-~-~-g~ucose~~~ is formed. A one-step hydrolysis of 112:3,4-di-0-isopropylidene-6-0-tosylHbO,
H60,
Hb0/IP
Hb0/Ip
1
HO~H HbOH
D-galactose t o 6-O-tosyl-@-~-galactosewas achievedlS2by heating an 8 % solution in acetic acid-water (3 : 1, by vol.) on the steambath for 2 hours. Similar procedures have been applied to “deacetonation ” of tosyl esters of 0-isopropylidene-ketoses, 193-6 to 1,2:5,6-di-O-isopropylidene-3,4-diO-tosyl-D-mannitol,1Se~1’7 t o methyl 3,4-O-isopropylidene-2-O-mesyl-~L ~ and ~ -2-0-tosyl-i3-~~~~-arabinoside, ~ and t o monotosyl esters of various monoanhydro-mono-0-isopropylidene-aldohexoses;2QQ-2Q2 and in no case were tosyl groups hydrolyzed off. (A boiling solution in 20% acetic acid was used in two201*202 instances.) There is a hint that partial de-mesylation of methyl 3,4-0-isopropylidene-2-O-mesyl-/?-~-arabinoside occurred on hydrolysis1s8with boiling 50% acetic acid. By treatment of N-tosyl-2,3-di-O-tosyl-5-O-trityl-adenosine (8% solution in 80 % acetic acid, under reflux for 30 minutes), the trityl group was removedlll without hydrolysis of the ribofuranosyl-adenine bond or detosylation, It should be noted that, on boilingyo3a 10% solution of 5,0-anhydro-2,4-0-benzylidene-1-0-tosyl-sorbitol in 50 % acetic acid, the tosyl group was retained and the benzylidene radical was removed, but the product was204 2,5anhydro-1-0-tosyl-L-iditol, formed as follows : (192) (193) (194) (195) (196) (197) (198) (199) (200) (201) (202) (203) (204)
H. Ohle and H. Thiel, Ber., 66, 525 (1033). H. Ohle and F. Just, Ber., 68, 601 (1935). W. R. Sullivan, J . Am. Chem. SOC.,67, 837 (1945). T. 5. Gardner and J. Lee, J . Org. Chem., 12, 733 (1947). P. Brig1 and H. Griiner, Ber., 07, 1969 (1934). L. F. Wiggins, J . Chem. SOC.,1403 (1947). J. K. N. Jones, P. W. Kent, and M. Stacey, J . Chem. Soc., 1341 (1947) P. W. Kent, M. Stacey, and L. F. Wiggins, J . Chem. SOC.,1232 (1949). H. Ohle and E. Euler, Ber., 63, 1796 (1930). R. M. Hann and C. S. Hudson, J . Am. Chem. SOC.,64,925 (1942). R. M. Hann and C. S. Hudson, J . Am. Chem. SOC.,08, 1867 (1946). L. von Vargha, Ber., 68, 1377 (1935). L.von Vargha and T. PuskBs, Ber., 70, 859 (1943).
SULFONIC ESTER8 OF CARBOHYDRATES
145
HzCOTs
KzCOTs I
I
____t
HbO' I
HkO
b H 3
Another organic acid which has been employed for debenzylidenation without desulfonylation is oxalic acid206 (3%, in boiling aqueous acetone). For a one-step hydrolysis of 1,2 :5,6-di-0-isopropylidene-3-O-tosyl-~glucose t o 3-O-tosyl-~-glucose (monohydrate), treatmentL6with sulfuric acid (0.15 M ) in aqueous ethanol a t 70" for 8 hours, followed by treatment with 0.3 N aqueous sulfuric acid at 70" for 8 hours, was employed. A similar, aqueous sulfuric acid-ethanol reagent was usedzosfor deacetonation, without demesylation, of 1,6-anhydro-3,4-0-isopropylidene-2-0mesyl-8-D-galactose (by boiling overnight). The isopropylidene group of 3,4-0-isopropylidene-l ,6-di-0-phenyl-2 ,5-di-0-t osyl-D-manni to1 was found'b' to be remarkably stable; refluxing for 8.5 hours was necessary or to cause deacetonation. Sulfuric acid in aqueous methanol,190~207-209 aqueous dioxane, lY4 has also been used to effect deacetonation without desulfonylation. Aqueous sulfuric acid (1 N ) during 4 hours under reflux simultaneously deacetonated and removed the glycosidic methyl group210 from methyl 3,4-0-isopropylidene-Z-O-mesyl-~-~-arabinos~de; to achieve the same effect with the corresponding ethyl glycoside, treatment210with boiling 1.75 N sulfuric acid during 5 hours was employed. Sulfuric acid in boiling aqueous acetone was eff ective211 for preparation of methyl 2,3-di-0-tosyl-/3-~-glucosidefrom its 4,6-O-benzylidene derivative. I n contrast t o these successful applications, it is recorded13that treatment of 1,2-0-isopropylidene-5,6-di-O-tosyl-~-glucose (having a primary and a secondary tosyloxy group adjacent) with 0.7 M sulfuric acid in aqueous ethanol (during 5 minutes at the boiling temperature, and then for 6 days a t 37") causes removal not only of the isopropylidene group but also of one tosyloxy group, to give a monoanhydro-mono-0-tosyl-D-glucose. (205) L. F. Wiggins, J. Chem. Sac., 522 (1944). (206) Sybil P. James, F. Smith, M. Stacey, and L. F. Wiggins, J. Chem. SOC.,625 (1946). (207) P. A. Levene and E. T. Stiller, J. Riol. Chem., 106, 421 (1934). (208) B. Helferich and H. Jochinke, Ber., 13, 1049 (1940). (209) S. Mukherjee and A. R. Todd, J . Chem. Soc., 969 (1947). (210) W. G . Overend and M. Stacey, J. Chem. Sac., 1235 (1949). (211) D. J. Bell and R. L. M. Synge, J. Chem. Sac., 1711 (1937).
146
R. STUART TIPSON
Hydrochloric acid in boiling aqueous acetone accomplishes debenaylidenation,z12-214deacetonation,216 and simultaneous deacetonation and detritylation,z06~216 all without desulfonylation. Hydrochloric acid in aqueous methanol causes (without desulfonylation) deacetonation, 167,169,210 and, more rapidly, de-ethylidenation. 167 Deacetonation, without desulfonylation, has also been brought about with hydrochloric acid in aqueous dioxanelg4 or aqueous a~etonitrile,~l7and with 0.5 N aqueous hydrochZoric acid.*0*21R Aqueous hydrochloric acid (0.1 N ) has also been used for de-ethylidenation. l g 4 Absolute methanol containing dry hydrogen chloride may be used for a variety of purposes without causing desulfonylation; thus, it brings about deacetonadetritylati~n,'~'deacetylation121g debensylidenati~n,~~**~~~ tion,144J69*220 glycoside formation, 116*19z-221 glycmide formation without deacetonation,222 and simultaneous gIycoside formation and deacetonation212~217~223-226 or de-cycl~hexylidenation~~~ (with some desulfonylation) In these reactions, the appropriate temperature, reaction time, and concentration of hydrogen chloride must be chosen with care; it is claimedzz3that methanol containing 1 % of hydrogen chloride not only deacetonates and glycosidates but also delosglutes 1,2-0-isopropylidene5-O-tosyl-~-xylose(and its 3-methyl ether), by treatment during 10 hours at room temperature. On the other hand, methyl 3,4-0-benzylidene-2O-tosyl-P-L-arabinosideis una$ectedla7by prolonged boiling with methanol containing 0.45% of hydrogen chloride; this may be an example of the greater stability of a secondary, as compared with a primary, tosyloxy group, or may be related to the effects of the differing cyclic-acetal rings present. Methanol containing dry hydrogen chloride has also been (212) D. J. Bell and S.Williamson, J . Chem. Soc., 1196 (1938). I
(213) J. S. D. Bacon, D. J. Bell, and J. Lorber, J . Chem. SOC.,1147 (1940). (214) G. J. Robertson and W. Whitehead, J . Chem. Soc., 319 (1940). (215) P. Karrer and P. C. Davis, Helv. Chim. Ada, 31, 1611 (1948). (216) J. S. D. Bacon, D. J. Bell, and H. W. Kosterlita, J . Chem. Soc., 1248 (1939). (217) J. W. H. Oldham and Mary A. Oldham, J . Am. Chem. Soc., 61,1112 (1939). (218) J. C. Sowden and H. 0. L. Fischer, J. Am. Chem. SOC.,64, 1291 (1942). (219) R. E. Reeves, M. H. Adams, and W. F. Goebel, J . Am. Chem. Soc., 62, 2881 (1940). (220) E. Elizabeth Percival and E. G . V. Percival, J . Chem. Soc., 690 (1950). (221) I. A. Forbes and E. G . V. Percival, J . Chem. Soc., 1844 (1939). (222) P. A. Levene and J. Compton, J . Biol. Chem., 116, 169 (1936). (223) G. J. Robertson and D. Gall, J. Chem. SOC.,1600 (1937). (224) S.Peat and L. F. Wiggins, J . Chem. SOC.,1088 (1938). (225) M. H. Adams, R. E. Reeves, and W. F. Goebel, J . BWE. Chem., 140, 653 (1941). (226) B. Iselin and T. Rcichstein, Helv. Chim. Ada, 29, 508 (1946). (227) R. C. Hockett,, R . E. Miller, and A. Scattergood, J . Am. Chem. SOC.,71, 3072 (1949).
SULFONIC ESTERS O F CARBOHYDRATES
147
employed for preparation228of methyl 2-0-phenylsulfonyl-3-deoxy-~(?)glycerate directly from the corresponding nitrile. Hot absolute methanol containing p-toluenesulfonic acid effectedZ28detoside. acetonation of methyl 3,4-0-isopropylidene-2,6-di-O-tosyl-c~-~-galac Absolute acetone containing dry hydrogen chloride has been employed for "acetonation l 1 (e.g., of 3-O-tosyl-~-glucose to16 its 1,2:5,6-di-O-isopropylidene derivative, by keeping a 6.6% solution in 1% hydrogen chloride-acetone for 20 hours a t room temperature), for simultaneous de-glycosidation and acetonation (as in the t r a n s f o r m a t i ~ nof~ ~methyl ~ 5-O-tosyl-~-arabinoside t o 1,2-0-isopropylidene-5-0-tosyl-L-arabinose) , and for d e b e n z y l i d e n a t i ~ nwithout ~~~ desulfonylation. A solution of concentrated sulfuric acid in acetone has also found use144for acetonation without desulfonylation. However, all other workers have preferred t o conduct this condensation in presence of a fourth component, viz., anhydrous copper sulfate, in much the manner first described by Ohle and von VarghaZ3lfor the preparation of 1,2 :3,5-di-0-isopropylidene-6-0-tosylD-glucose (originally called 6-tosy~-isodiacetone-~-g~ucose) ; this involves shaking a t room temperature for 2 days. Addition of a few drops of acetaldehyde232per liter of acetone has been recommended. Acetonation of 6-O-tosyl-~-ga~actose diethyl mercaptal gave a mixture233of its monoand di-0-isopropylidene derivatives. A mixture of acetic anhydride, glacial acetic acid, and concentrated sulfuric acid (60 :40 :2.5, by vol.) transformss2 methyl 2,3,6-tri-0-methyl4-O-tosy~-a,/3-~-g~ucoside t o l-O-acetyl-2,3,6-tri O--methyl-4-O-tosyl-~glucose after 2 days a t 15 to 20"; the p-form of the latt,er is converted to the a-form by a similar mixture (70:30:2.5; by vol.) in 24 hours a t room temperature. The corresponding 5-O-tosyl-p-~-glucofuranoside behaves234similarly. By treatment with the acid acetylating solution, simultaneous debenzylidenation and acetylation of 2,3,4,5-di-O-henzylidene-l16-di-0-tosyl-~-mannito~ occurs (during 19 hours a t 25'), affordin 85 % yield. On ing2362,3,4,5-tetra-~-acetyl-l,6-d~-~-tosyl-~-mariri~tol the other hand, action of the acidic acetylating solution on 1-0-mesyl2,4:3,5-di-0-methylene-~,~-xylitol during 15 minutes at 0" gives rise'*O t o (228) J. Lichtenberger and C. Faure, Bull SOC. chim. France, 995 (1948). (229) E. L. Hirst, J. K. N. Jones, and Elin hl. L. Williams, J . Chem. Soc., 1062 (1947). (230) D. S. Mathers and G. J . Robertson, J . Chem. SOC.,1076 (1933). (231) H. Ohle and L. von Vargha, Ber., 61, 1208 (1928). (232) H. B. MacPhillamy and R. C. Elderfield, J . Org. Chevn., 4, 150 (1939). (233) J. English, Jr., and W. H. Schuller, J . Am. Chem. SOC.,74, 1361 (1952). (234) K. Hess and K. E. Heumann, Ber., 72, 149 (1939). (235) W. T. Haskins, R. M. H a m , and C. 8. Hudson, J . Am. Chem. SOC.,66, 1419 (1943).
148
R. STUART TIPSON
3-0-acetoxymethyl-5-O-acetyl-1-0-mesyl-2,4-0-methylene-~,~-xylitol ;the 1-0-tosyl derivative behaves analogously. Glacial acetic acid plus concentrated hydrochloric acid was usedlg6for deacetonation of a di-0-benzoyl. mono-0-isopropylidene-di-0-tosyl-Dmannitol (during 5 hours a t 15-20'>, and for hydrolysis23Eof the diethyl acetal of 2,3-di-0-tosyl-~,~-glycerose by treatment during one hour at 100-105°. Glacial acetic acid containing dry hydrogen bromide (usually prepared by saturation a t 0') yields glycosyl bromides, without desulfonylation. The reagent gives best results if the hydroxyl group at carbon atom 1 isJirst acetylated. Thus, by reaction during 14 hours at O", it transforms16 1,2,4,6-tetra-0-acetyl-3-0-toayl-~-~-glucose into 2,4,6-tri-O-acetyl3-0tosy~-a-D-glucosylbromide (in 96% yield). The reagent is just as
7
AcOCH
I
HCOAc
TsOhH H A 0 Ac
I
HCOhH*OAc
satisfactory if a mesyl group is situated a t position 3lg0or 6;24 and with 47 238 61 143-171~1*2-221-239 compounds having a tosyl group a t position 2;l4*gZa7 or at positions 2 and 6.142By action on 2,3,6-tri-O-tosyl-~tarch,~~~ during 15 days a t room temperature, it causes hydrolysis to monosacch ride units, and glycosyl-bromide formation, to yield 4-0-acetyl-2,3,6-tri-Otosyl-a-D-glucosyl bromide. Analogous results are obtained with 2,3,diO-tosyl-6-deoxy-6-iodo-starch,10gand with 2,3-di-0-tosyl-6-formylstarch.241 Another use is exemplified by the conversion,239in 75% yield, chloride to the corresponding of 3,4,6-tri-0-acetyl-2-O-tosyl-a-~-g~ucosy~ bromide by treatment during 48 hours a t room temperature. Usable, though frequently less satisfactory, because of complications, is the action of hydrogen bromide-acetic acid on sulfonic esters of 1,2-0(236) P. Karrer, E.Schick, and R. Schwyser, Helv. Chim. Ada, 31, 784 (1948). (237) E.Hardegger, 0.Jucker, and R. M. Montavon, Helv. Chim. Ada, 31,2247 (1948). (238) B Helferich and A. MiiIler, Ber., 63,2142 (1930). (239)B. Helferich and S. Griinler, J . prakt. Chem., 148, 107 (1937). (240) K.Hem, 0.Littmann, and R. Pfleger, Ann., 607, 56 (1933). (241) D.Gottlieb, C.G. Caldwell, and R. M. Hixon, J . Am. Chem. SOC.,62,3342 (1940).
SULFONIC ESTBRS O F CARBOHYDRATES
149
isopropylidene-aldoses. Here, its usual function is deacetonation, followed by acetylation and glycosyl-bromide formation. If the hydroxyl group at carbon atom 5 of glucose is free, or is substituted by an acidlabile group, e.g. , a (shared) isopropyliderie group, hydrolysis of the isopropylidene groups occurs and the oxygen-ring changes from furanose to pgranose before acetylation and bromide formation take place, but the ~ ~ material containing firmly bound, nonproduct is ~ o n t a m i n a t e d 'with ionizable bromine. Thus, treatment of 1,2:5,6-di-O-isopropylidene-3O-tosyl-D-glucose16~1g~8s or of 1,2-O-isopropy~idene-3-O-tosy~-~-glucofuranI
TsOr I
€I I 0-
HhO
I \
ose90 with the reagent gives 2,4,6-t~ri-0-acetyl-3-C-tosyl-a-~-glucosyl bromide, identical with that obtainedI6from similar treatment of 1,2,4,6tetra-0-acety~-3-0-tosyl-D-g~ucose. The same kind of behavior is shownH5,lY by 1,2:3,5-di-0-isopropylidene-6-O-tosyl-~-glucose~ though the yield is low (possibly because of some det,osylation);and it is claimedgo.*al that, on treatment'38 of 1,2-O-isopropylidene-6-O-tosyl-~-glucofurano~e, there is retention of the furanose ring in at least part of the resulting bromide, The furanosyl bromide was not readily isolated, but was recognixed by transformation, by means of methanol plus silver carbonate, t o methyl 2,3,5-tri-0-acetyl-6-O-tosyl-~-~-g~ucoside, On the other hand, if the hydroxyl group at carbon atom 5 is protected by an acid-stable group (e.g., an acyl group), the furanose ring is unquestionably retained. Thus, 5,6-di-O-acetyl-l,2-O-isopropylidene-3-O-tosylD-glucose gives86,242 2,5,6-tri-0-acety~-3-O-tosy~-a-D-g~ucosy~ bromide; and the 3 ,5,6-tri-0-tosyl, 6-0-beneoyl-3,5-di-O-tosyl, 138 and 5,6-diO - b e n ~ o y l 3 - O - t o s y lderivatives ~ ~ ~ ~ ~ ~ ~ of 1,2-O-isopropylidene-aglucofuranose behave similarly. In isolat,ing these rather labile furanosyl bromides, removal of excess hydrogen bromide is best achieved86 by addition of an ethereal solution of ethyl-magnesium bromide; in this way, 2-O-acety1-3,6-anhydro-5-0-tosyl-a-~-glucosyl bromide was successfully preparedzn0from both the l12-di-0-acetyl and the l12-0-is0(242) H. Ohle and H. Erlbach, Ber., 61, 1870 (1928).
150
R. STUART TIPSON
propylidene derivatives of 3,6-anhydro-5-O-tosyl-~-glucose.In reference to the previously mentioned material containing tenaciously bound bromine, it should be noted that the action of hydrogen bromide-acetic acid on 5,6-di-0-acetyl-1,2-O-isopropylidene-3-O-mesyl-~-glucose had been thought lgO to yield 2,5,6-tri-0-acetyl-3-0-mesyl-~~-~-glucosyl bromide, but the product was later recognised to be2435,6-di-O-acetyl-1,2-0-(~~bromoethylidene)3-0-mesyl-D-glucose,formed as follows : HbO
t:
MsO H HA0 HbOAc LHIOAC
CHs
HhO
Br
b i4 &-MsO H
HAOAC
AII,OAo
A less concentrated solution of hydrogen bromide in glacial acetic acid is useful for achieving d e t r i t y l u t i ~ n ' ~without ~ , ' ~ ~ ~desulfonylation, ~~~ as in the preparation of methyl 4-0-acetyl-2,3-di-0-to~yl-a10E (or plO9)-~glucoside from the corresponding 6-0-trityl derivative by reaction for 5 minutes at 0". (Simultaneous detritylation and acetylation has been accomplished164with acetyl bromide in glacial acetic acid during 10 minutes at OO.) An interesting property of acetic anhydride-hydrogen bromide (saturated at 0') is that it demethylates and then acetylates a methylated sugar, as well as forming the glycosyl bromide (without desulfonylation) ; thus, it changesa44methyl 2,3,6-tri-0-rnethyl-4-0-t0syl-~~,~-~-glucoside into 2,3,6-tri-0-acety~-4-O-tosy~-cr-D-g~ucosy~ bromide on reaction in a sealed tube at +loo for 40 hours.
(243) B. Helferich and H. Jochinke, Ber., 74, 719 (1941). (244) K. Hem and F. Neumann, Bey., 68, 1371 (1935).
SULFONIC ESTERB OF CARBOHYDRATES
151
For the preparation of glycosyl chlorides without desulfonylation, acetic anhydride-hydrogen chloride (saturated a t - IS') is a valuable reagent which convertsls2for example, methyl 2,3,6-tri-O-methy1-4-0tosyl-a,p-D-ghcoside (in a sealed tube at +lo' for 3 days) to 2,3,6-tri-Omethyl-4-0-tosyl-a-D-glucosyl chloride. 2,4,6-Tri-O-methyl-3-O-tosyl-c~D-galactosyl chloride has been prepared lZ6 similarly. The same reagent, or dry ether saturated with hydrogen chloride, t r a n s f o r m ~ ~methyl ~~~~4~ 2,3,6-tri-O-methy1-5-0-tosyl-cu (or P)-D-glucoside to a 30: 70 mixture of the a and fl forms of 2,3,6-tri-O-methyl-5-0-tosyl-~-glucosyl chloride. Some other reactions which have been conducted under acidic conditions without causing desulfonylation are as follows. Methylenation of 6-deoxy-2,4-O-methylene-l-0-tosyl-sorbitoloccurred170when a solution of the compound in dioxane plus 37% aqueous formaldehyde was sat8urated at 0" with dry hydrogen chloride and then kept at -1-5" for 24 hours. Benzylidenation of 1,4-anhydro-6-0-tosyI-sorbitolwas achieved72 by stirring with benzaldehyde plus aqueous hydrochloric acid during 3 hours at room temperature. A less convenient method of benzylidenation employs zinc c h l ~ r i d 217 e ~246~instead ~ ~ ~ ~of hydrochloric acid. Mercaptalation of 6-0-mesyl-D-galactose to its diethyl and dibenzyl mercaptals was effected16gby mixing the compound with the respective mercaptan plus concentrated hydrochloric acid at 0", and then shaking for 2 hours a t room temperature. Here, too, zinc chloride may replace the hydrochloric acid, as in the preparationzq7of 6-O-tosyl-~-galactosediethyl mercaptal. may replace sulfuric acid in Likewise, anhydrous copper condensing the 3 - 0 - t 0 s y l ~ ~ (but , ' ~ ~ notz3] the 6-0-tosyl) derivative of 1,2-O-isopropylidene-~-glucofuranosewith acetone. Removal of a nitrate group, without desulfonylation, is readily accomplished by Oldham's method248which consists of reduction by boiling a 5 % solution of the compound in glacial acetic acid with iron dust until a test portion shows no response to the diphenylamine-concentrated sulfuric acid test for nitrate. An improvement20 is the use of a mixture of zinc dust and iron dust, instead of iron dust alone, for removal of 6-nitrate20-176a249 and 3-nitrateZs0groups. Other reactions accomplished in glacial acetic acid without desulfonylation, include osazone formation120'J semicarbazone formation,2K and oxidation a t a terminal hydroxyl or a t (245) K. Hess and K. E. Heumann, Ber., 72, 1495 (1939). (246) A. 5. Meyer and T. Reichstein, Helv. Chim. Acla, 29, 139 (1948). (247) F. Micheel and H. Ruhkopf, Ber., 70, 850 (1937). (248) J. W. H. Oldham, J . Chem. SOC.,127, 2840 (1925). (249) D. J. Bell, J . Chem. SOC., 1180 (1935). (250) J . Dewar and G. Fort, J . Chem. Soc., 496 (1944). (251) W. T. Haskins, R. M. Ham, and C . S. Hudson, J . Am. Chem. Soc., 67, 1800 (1945).
152
R. STUART TIPSON
vicinal free hydroxyl groups by means of lead t e t r a a ~ e t a t at e ~ room ~~~~~ temperature. (Oxidation with lead tetraacetate may also be perforrned2O4 in benzene solution.) Chromium trioxide in acetic acid was employedlg4 for oxidizing 1,3:2,4-di-0-ethylidene-6-0-tosyl-~-glucitol t o keto-3,5 :4,6di-0-ethylidene-1-0-tosyl-L-sorbose; this, incidentally waa a new way for preparing keto-sugars. Metallic acetates, e.g., of thallium, l8 ~ i l v e r , ~ ~ ~ ~ or leads6Bzoo(tetraacetate, with an air current t o remove liberated bromine), react with glycosyl halides in acetic acid to give the corresponding 1-0-acetyl derivatives, without desulfonylation. b. Slightly Acidic, Neutral, and Slightly Basic Environments.-By treatment with boiling acetic anhydride, acetylation of free hydroxyl groups (without desulfonylation) may often be a c c ~ m p l i s h e d . ~ Thus, ~~ after exactly 5 minutes, 1,2-0-isopropy1idene-5,6-~di-0-tosy1-~-g1ucose was transformed to its 3-acetate (but, after 10 minutes, decomposition had commenced). Introduction of anhydrous sodium acetate is therefore advisable; the acetylation may then be performedy9~1z4~190~zz4 at 100". [If, however, such a mixture is boiled for 5 hours under reflux, there is a danger that some tosyl groups may be r e p l a ~ e by d ~acetyl ~ ~ ~ groups; ~ both a 6-0-mesyP4 and a 6-0-tosyl group have been so replaced2S2 (see, also, p. 214). Similarly, acetic anhydride containing anhydrous zinc chloride can cause247simultaneous detosylation and acetylation a t position 6 of a hexose; thus, treatment of 2,3,4,5-tetra-O-acetyl-6-0-tosylaldehydo-D-galactose with these reagents, during 4 hours on the steam bath, gave247hepta-0-acetyl-aldehydo-~-galactose.] A related acylation, with no complications, is the preparation263of methyl 4,6-0-benl;ylidene2-0-tosy~-3-0-trifluoroacety~-a-~-glucoside by the action of trifluoroacetic anhydride plus sodium trifluoroacetate in carbon tetrachloride (under reflux, during 75 minutes) on methyl 4,6-0-benzyIidene-2-O-tosyl-a-~-glucoside. Methylation of free hydroxyl groups by means of Purdie's reagents usually proceeds smoothly, 176 without occurrence of desulfonylation. 230 Thus, by treatmentz0 of methyl 2,3-di-O-methyl-4-0-phenylsulfonyl@-D-glucosidewith silver oxide plus boiling methyl iodide under reflux, the 2,3,6-trimethyl ether was obtained. However, although methyl 2-0-tosyl-P-~-g~ucosideis readily methylated2S4 t o yield its 3,4,6-trimethyl ether, methyl 3-O-tosyl-/3-~-glucosideallegedly decomposesz17on attempted methylation with Purdie's reagents. In view of the fact that the same authors217 experienced no difficulty in methylating methyl 3-O-tosyl-a-P-~-glucoside, the most likely explanation is that the sample (252) K. Freudenberg and K. von Oertzen, Ann., 674, 37 (1951). (253) E. J. Bourne, M. Stacey, Mre. Clarice E. M. Tatlow, and J. C. Tatlow, J . C h m . SOC.,826 (1951). (254) W. N. Haworth, E. L. Hirat, and L. Panizzon, J . Chem. Soc., 164 (1934).
SULFONIC ESTERS O F CARBOEYDRATES
153
of supposed methyl 3-0-tosyl-P-~-glucosideused as starting material had already been partially detosylated during its preparation (by action of sodium methoxide on methyl 2,4,6-tri-0-acetyl-3-O-tosyl-/3-~-glucoside; see p. 167); another possible explanation is that the specimen of silver oxide employed in the methylation had been imperfectly freed from alkali prior to use. The same authors were unable2I7 to methylate and “it was assumed methyl 4,6-0-benzylidene-3-O-tosyl-p-~-glucoside that methylation had been prevented by steric hindrance,” yet methyl 4,6-0-benzylidene-2-O-tosyl-a-~-glucoside~~~ and methyl 4,6-O-benzylidene-3-O-tosyl-~-~-galactoside~~~ may be methylated without difficulty. It should be noted that methylation by Haworth’s method (with dimethyl sulfate plus aqueous sodium hydroxide solution) is inapplicable t o methylation (without desulfonylation) of sulfoiiic esters of carbohydrates, because of the alkaline environment employed, Thus, on subjecting266 methyl 2,4,6-tri-0-acetyl-3-O-tosyl-~-~-glucoside to the action of Haworth’s reagents, the product was224methyl 3,4-anhydro-2,6-di-Omethyl-p-D-alloside (see p. 172). Introduction of a methyl group at carbon atom 1 mayLbe brought about by the Koenigs and K n 0 1 - rmethod. ~~~ This involves the reaction of anhydrous methanol with a glycosyl halide, in the presence of anhydrous silver carbonate (which serves to neutralize the hydrogen halide liberated). The mixture is shaken (usually, at room temperature; with provision for escape of the carbon dioxide formed) until a filtered test portion of the solution is free from ionizable halogen. Thus, after shaking for 14 hours at room temperature, 2,4,6-tri-~-acety~-3-0-tosy~-a-~-g~ucosy~
7
HCBr
h TsOhH
H OBc
HhAc
A
H 0I
7
MeOCH
(Inversion)
CH~OAC
&OAc
b
TsO H HLOAc
A
H 0-
I ~H~OAC
bromide gavel6methyl 2,4,6-tri-0-acetyl-3-O-tosyl-/3-~-glucoside. (Vanillin may be used, instead of methanol, for preparing239the corresponding vanillin p-D-glucoside.) Furanosyl halides react as s a t i s f a c t ~ r i l yas~ ~ ~ ~ ~ ~ ~ pyranosyl halides. However, as previously mentioned (see p. 150), supposed glycosyl bromides prepared from certain isopropylidene derivatives may consist partly (or even solely) of material containing firmly-bound (255) K. Freudcnberg and E. Plankenhorn, Ann., 636, 257 (1938). (256) W. Koenigs and E. Knorr, Ber., 34, 957 (1901).
154
R. STUART TIPSON
bromine; such specimens giveg0unsatisfactory results. The glycosyl bromide which is actually2435,6-di-0-acetyl-l,2-0-~a-bromoethylidene)-3-0-mesyl-~-ghcose reacts with methanol (in the presence of benzene and pyridine) t o give the corresponding a-methoxyethylidene derivative :
-
HbO
Br
I
HbO
b
H OAc
I
HbO
OCHs
&
H OAc
&H20Ac
AHpOAc
The a-amyloxyethylidene and a-benzyloxyethylidene derivatives were prepared243similarly. A sulfonyl group a t positions 4,164288,289 5 138 or 6,23,86.90.148.171,191,221, 2a1*289,257 does not change the reactivity of the bromide, but a tosyl group at position 2840230 apparently lowers the reactivity of the bromide124~142~240 and most certainly lowers that of the chloride. Thus, in order to prepare from the corresponding methyl 3,4,6-tri-0-acetyl-2-O-tosyl-~-~-glucoside a-D-glucosyl chloride it was found necessarys3 to boil the methanol solution with silver nitrate plus pyridine under reflux for 8 hours (yield, 60 %) ; similarly, 2,3,4,6-tetra-0-tosy~-cu-~-g~ucosyl chloride was boiled under reflux with methanol plus silver oxide for ten days126in order to produce the corresponding @-D-glucoside. If, in the foregoing reaction of glycosyl bromides, the methanol is replaced by moist acetone, exchange of the bromide ion for hydroxyl takes place. For example, 2,4,6-tri-0-acetyl-3-O-tosy~-a-~-g~ucosy~ bromide givesl9. 2,4,6-tri-O-acet yl-3-04 osyl-p-D-gluc ose :
(Inversion)
"j
TsO H
HAOAc HbO
(257) B. Helferich, R. Hiltmann, and W. Reischel, Ann., 684, 276 (1938).
SULFONIC ESTERg O F CARBOHYDRATES
155
The reaction succeeds equally ell^^^^^^^ with furanosyl bromides, includ~~ presence of a tosyl group at posiing those having a 5 - O - t o ~ y l 'group; tion 2 may reduce the reactivity since, for preparation of 4-0-acetyl-2,3,6tri-0-tosyl-~-glucose, treatment with silver oxidel 2 (instead of silver carbonate) was used. Here, again, the chlorides are less reactive than the bromides; thus preparation of 2,3,6-tri-0-methyl-4-0-tosyl-~glucose from its glucosyl chloride requiredS2shaking for 3 days, and shaking for 50 hours was used in converting'26 2,4,6-tri-O-methy1-3-O-tosyl-aD-galactosyl chloride to the corresponding sugar. bromide Despite the fact that 2,4,6-tri-0-acetyl-~-0-tosy~-a-~-g~ucosy~ reactss5 with silver p-toluenesulfonate in pyridine to give a glucosylpyridinium p-toluenesulfonate (see, also, p. 120), it is claimed23' that bromide with treatment of 3,4-di-0-acetyl-2,6-di-O-tosyl-a-~-glucosyl silver acetate in pyridine (at 50' for only d minutes) affords 1,3,4-tri-Oacetyl-2,6-di-O-tosyl-~-~-glucose. Titanium tetrachloride, a very powerful electrophilic compound introduced by Pacsu268for converting P-glycosides to a-glycosides and for preparing a-glycosyl chlorides, can be employed for these purposes without causing desulfonylation. Thus, the conversion of methyl 2,3,6-tri-0-methyl-5-O-tosyl-P-~-glucoside to its a-form by means of 1.1 molar proportions of titanium tetrachloride in very dry chloroform is in~tantaneous~3~ a t room temperature; similar conversion of methyl 2,4,6-tri-0-acetyl-3-O-tosyl-~-~-glucoside to its a-form requiredI4O one hour's refluxing. For preparation of a-glycosyl chlorides from the l-0-acetyl derivatives, treatment in dry chloroform a t 50" for to 18OZo0minutes is necesscary. Titanium tetrabromide has been similarly employed200 for preparation of an a-glycosyl bromide from the corresponding l-0-acetyl derivative. Stannic ch2oride in dry chloroform, also U , ~used ~ ~for transforming86 1,2,3,4-tetra-Ointroduced by P ~ C S was acety~-6-0-tosyl-~-~-glucose to its a-anomer by treatment at 50" during 5 hours. Mercuric chloride in dry benzene effected the conversion124(on refluxing for 16 hours) of 4-0-acetyl-2,3,6-tri-O-tosy~-a-~-glucosy1 bromide to the corresponding chloride, a compound which, in addition to being a chloride, has a 2-O-tosyl group; it is therefore very unreactive. A solution of silver nitrate in acetonitrile converts w-deoxy-w-iodo-aldose derivatives to the corresponding w-nitrates without20~123-Z80 occurrence of desulfonylation. Thus, methyl 2,3-di-0-acetyl-6-deoxy-6-iod0-4-0tosyl-P-~-glucosidegavez0an 89% yield of the &nitrate after boiling for 2 hours. Boiling for 4 hours was required for preparation of methyl 2,3,4(258) E. Pacau, Ber., 61, 1508 (1928). (259) E.PacBu, Ber., 61, 137 (1928). (260) D.J. Bell, J . Chem. Soc., 1177 (1934).
156
R. STUART TIPSON
tri-0-tosyl-6-D-glucoside 6-nitrate, and methyl 6-deoxy-6-iodo-2,3-di-Omethyl-4-0-phenylsulfonyl-/3-D-glucoside was even less reactive, requiring overnight treatment at 100’ to give an 80% yield of crude 6-nitrate. Silver acetate in acetic anhydride-pyridine (4 : 1, by vol.) similarly conv e r t ~6-deoxy-6-iodo ~ ~ ~ # ~ ~ derivatives ~ to the 6-acetates by boiling gently for 5 minutes; thus, both the (Y and @ anomers237and the p-glu~oside’~~ of 1,3,4-tr~-0-acetyl-6-deoxy-6-iodo-2-0-tosyl-~-glucose give the corresponding 6-acetates. Similarly, silver acetate (formed in situ from silver nitrate plus an equimolar proportion of sodium acetate) in 25% aqueous acetone reacted249with methyl 6-0-dichloroacetyl-2,3,4-tri-O-tosy~-P-Dglucoside (under reflux during 3 hours) t o give, supposedly, the 6-0-acetyl derivative; but methyl 2,3-di-0-benzoyl-6-0-dichloroacetyl-4-O-to~y1-c~D-glucoside was unaffected24gby this reagent under the same conditions. Silver fluoride in pyridine is capableTg of reacting on an w-deoxy-w-iodo derivative to give a compound containing a terminal double bond, without causing desulf onylation. Demercaptalation (without desulfonylation) is readily accomplished2e1 by Wolfrom’s method.261a Thus, treatment of a stirred solution of 5-O-tosyl-~-arabinosediethyl mercaptal in aqueous acetone with cadmium carbonate plus mercuric chloride (for 16 hours at room temperature and then 4 hours at 50”) gives134 5-O-tosyl-~-arabinose. Similarly, 2,3,4,5tetra-0-acety~-6-0-tosyl-~-galactosediethyl mercaptal affords247 2,3,4,5-tetra-0-acetyl-6-0-tosyl-a~dehydo-~-ga~actose. By using Pacsu’s method,262which involves treatment with a boiling solution of mercuric chloride in absolute methanol for 10 minutes, 5-O-tosyl-~-arabinosediethyl mercaptal was converted directly to134methyl 5-O-tosyl-~-arabinoside. Under appropriate conditions, catalytic reduction may be applied to sulfonic esters of sugars without causing their desulfonylation (see, however, p. 163). Thus, removal of the benzylcarboxy group from 5-0-benzylcarboxy-1,2-0-isopropylidene-3-0-tosyl-~-xy1ose was accomplished’le by shaking a suspension in 95% ethyl alcohol with Raney nickel plus hydrogen (at a pressure of 45 lbs. per square inch) during 4 hours at room temperature. Debenzylidenation may also be accomplished; thus, by hydrogenationI8 of 5,6-O-benzylidene-l,2-0-isopropylidene-3-O-mesyl-~glucose in the presence of a palladium catalyst, during one hour, 1,2-0isopropylidene-3-0-mesy~-~-glucofuranosewas produced. Levene and Compton’s catalytic method263for transformation of an w-deoxy-w-iodosugar derivative t o the w-deoxy compound may be successfully applied (261) F. Micheel and F. Suckfull, Ann., 602, 85 (1933). (261a) M. L. Wolfrom,J. Am. Chem. SOC.,61, 2188 (1929). (262) E. Pacsu, Bey., 68, 509 (1925). (263) P. A. Levene and J. Compton, J . Biol. Chem., 111, 325 (1935)
SULFONIC ESTERS O F CARBOHYDRATES
157
to sulfonic esters without causing desulfonylation (despite the alkaline conditions required), provided that the sulfonyloxy group is “isolated.” That is t o say, the hydroxyl groups of the carbon atoms adjacent t o the sulfonyloxy group should bear substituents not hydrolyzed off by alkali (see. p. 169). Alternatively, the alkali usually employed should prefera~ l acceptor for the hydriodic acid bly be replaced by d i e t h y l ~ r n i n e ~as liberated. An example of the first procedure is the preparation264of 6-deoxy-2,3-0-isopropylidene-l-O-tosyl-~-sorbose (formerly called “2,30-isopropylidene-1-0-tosyl-L-sorbomethylose”)by shaking a solution of the 6-deoxy-6-iodo derivative in methanol containing sodium hydroxide with hydrogen under slight pressure, in the presence of Raney nickel, during 30 minutes. The method has also been utilized for formation of the w-deoxyalcoholic (w-C-methyl) groups of (sulfonic esters of) 6-deoxy~ - f r u c t o s e (“D-fructomethylose”), ~~~ 6-deo~y-sorbitol’~~ (“D-epirham~~ ”) , nitol ”) , l15-dideoxy-ribitol, 266 6 - d e o x y - ~ - a l t r o s e(“~ D-altromethylose 6-deoxy-3-0-methyl-~-galactose~~~ (“D-digitalose ”), 2,6-dideoxy-3-0methyl-~-ribo-hexose~~~ (2,6-dideoxy-3-0-methyl-~-“allose,” (‘cymarose”), 6-deoxy-~-galactose~~~ (“D-fucose”), 2,6-dideoxy-3-0-methyl~ - l y x o - h e x o s e ~(2,6-dideoxy-3-0-methyl-~-“galactose,” ~~ “2-deoxy-3-0methyl-D-fucose,” or D-diginose ”), and 2,6-dideoxy-3-O-methyl-~-xylohexose2T1(2,6-dideoxy-3-0-methyl-~-“gulose” or (‘~-sarmentose”)derivatives. On so h y d r ~ g e n a t i n g ‘ 3,5-di-O-acetyl-6-deoxy-6-iodo-2,4-0~~ methylene-1-0-tosyl-sorbitol, absorption of excess hydrogen was noted, suggesting a side-reaction involving formation of an anhydro-ring or of an unsaturated derivative; the yield of 6-deoxy-2,4-0-methylene-l-Otosyl-sorbitol was only 28 % of the theoretical when 3.3 molar equivalents of sodium hydroxide (two of which were presumably taken up by the acetyl groups) were employed. For reduction of 1,5-dideoxy-lJ5-diiodo2,4-0-methylene-3-0-tosyl-ribitol,1.1 molar proportions of barium methoxide were used, and the diiodo compound and Raney nickel were addedzBB in two portions, the second addition being made after 10 minutes of hydrogenation and being followed by a further 15 minutes of hydrogenation; this gave a 91 % yield of desired l15-dideoxy derivative. However, the best way of avoiding excess alkalinity (when sodium hydroxide is used) consists in slow, dropwise268addition of 0.8% sodium (264) (265) (266) (267) (268) (269) (270) (271)
H. Miiller and T . Reichstein, Helv. Chinz. Acta, 21, 263 (1938). W. T. J. Morgan and T . Reichstein, Helu. Chim.Acta, 21, 1023 (1938). R. M. Hann and C. S. Hudson, J. Am. Chem. SOC.,66, 1906 (1944). C. A. Grob and D. A. Prins, Helv. Chim. Acta, 28, 840 (1945). F. Reber and T . Reichstein, Helv. Chim.Acta, 29, 343 (1946). D. A. Prins, Helv. Chim.Acta, 29, 378 (1946). C. Tamm and T . Reichstein, Helv. Chim.Acta, 31, 1630 (1948). H. Hauenstein and T. Reichstein, Helv. Chim.Acta, 88, 446 (1950).
158
R. STUART TIPSON
hydroxide in absolute m e t h a n 0 1 , ~ ~ 6 - ~during 6 ~ - ~ ~the ' hydrogenation. An even safer procedure261entails use of 2 molecular equivalents (per iodine atom) of diethylamine, instead of the sodium hydroxide. This method has been employed for formation of (sulfonic esters of) l,g-dideoxy-~mannitol, 261 1,6-dideoxy-~-mannitol (" l-deoxy-L-rhamnitol ") ,261 and 6-deoxy-~-glucose (" D-quinovose") .272 Sulfonyloxy groups are usually stable under the conditions employed for acetylation, benzoylation, and tritylation in pyridine. However, with acetyl chloride, benzoyl chloride, and triphenylmethyl chloride in pyridine, the possibility of chlorination (by replacement of sulfonyloxy groups, see p. 121) must be borne in mind. Furthermore, quinolinium chloride (and, to a lesser degree, pyridinium chloride) can catalyze migration273of isopropylidene groups, particularly in reactions performed above room temperature. For these reasons, instead of acetyl chloride, acetic anhydride in pyridine is the preferred acetylating agent; it is usually employed instead of acetic anhydride or acetic anhydride-sodium acetate because these reagents, too, may cause undesired side-reactions (see p. 151). Whereas p-toluenesulfonyl chloride in pyridine does not cause migration of a trifluoroacetyl group, acetic anhydride in pyridine26a does; this is the only untoward effect of the latter reagent which has been encountered in the literature. The first example of acetylation of a sulfonylated sugar was the preparation16 of 1,3,4,6-tetra-O-acetyl-3-0tosyl-@-glucose by treatment of 3-O-tosyl-~-glucose with excess acetic anhydride plus pyridine during 20 hours a t room temperature; 1,2,3,4tetra-0-acety~-6-0-tosy~-~-~-g~ucose was similarly prepared1g1by acetylation during 3 days at 37". The reagent may be applied to acetylation of O-sulfonyl-sugars bearing such groupings as 1,2-O-i~opropylidene,7~~~~~ methyl g l y c o ~ i d e , diethyl ' ~ ~ ~ ~m ~~ e r ~ a p t a l 6-0-trity1,219~22b ,~~~ 6-deoxy-6i 0 d 0 , l ~3~, 6 - a n h y d r 0 , ~andzo1 ~ ~ ~ ~ 1,6-anhydro. ~~ For preparation249of the latter the 6-dichloroacetate of methyl 2,3,4-tri-0-tosyl-P-~-glucoside, was dissolved in dry pyridine at - lo", a solution of dichloroacetyl chloride in dry benzene was added dropwise, with stirring, and the mixture was kept at 0" for 3 hours (yield, 94%). Benzoylation of free hydroxyl groups by means of benzoyl chloride in pyridine may usually be satisfactorily achieved at room temperature; but, if the reaction a t this temperature is prolonged or if elevated temperatures are employed, impure products (possibly containing contaminants formed by reaction, particularly of primary tosyloxy groups, with (272) E. Hardegger and 0. Jucker, Helv. Chim. Ada, 32, 1158 (1949). (273) R. M. Hann, W. D. Maclay,.and C. 5. Hudson, J . Am. Chem. Soc., 61,2432 (1939).
SULFONIC ESTERS O F CARBOHYDRATES
159
pyridine or pyridinium chloride) may result. Thus, no difficulty was experienced in the u n i m ~ l a r ~ or~ dim01ar~~ ~ ' ~ ~ benzoylation of 1,2-0isopropy~idene-~-0-tosyl-~-g~ucofuranose (having a secondary tosyloxy group) to yield the 6-benzoate and 5,6-dibenzoate, respectively. On the other hand, dimolar b e n ~ o y l a t i o n ~ of ~ . "1,2-0-isopropylidene-6-O-tosyl~ D-glucofuranose (having a primary tosyloxy group) was unsatisfactory when performed either during 6 days73at 40" or during 30 hours114at 60". Furthermore, on treating 1,2-O-isopropylidene-5,6-di-O-tosy~-~-g~ucose with 2 molar proportions of benzoyl chloride in pyridine, during 4 days at 37", one third of the starting material was recovered unchanged, and, instead of being the expected 3-0-benzoyl-5,6-di-0-tosyl derivative, the product was allegedly73 a mono-O-benzoyl-l,2-0-isopropylidene-mono0-tosyl-D-glucofuranose. By benzoylation during 16 hours at room gave133 an 88 % temperature, 1,2-0-isopropy~idene-5-O-tosyl-~-xylose yield of its 3-benzoate; and p-nitrobenzoylation of methyl 2-O-tosyl-p-~arabinoside readily aff ~ r d e d its ~ ' 3,4-bis-p-nitrobenzoate. ~ Since the procedure of tritylation in pyridine has so far only been employed for introduction of a triphenylmethyl group at a free primary hydroxyl group of 0-tosyl derivatives of sugars, the possible complications engenderable by reaction of a primary tosyloxy group with pyridinium chloride have naturally not been reported. For isolation of a crystalline product, it is often necessary that any free secondary hydroxyl by addition of acetic anhydride after the groups be acetyEated10g.214,21g,226 tritylation is judged to be complete. Thus, treatmentlo* of methyl 2,3-di-O-tosyl-a-~-glucoside with 1.1 molar proportions of trityl chloride in pyridine, during 4 hours a t loo", was followed by addition of excess acetic anhydride and preservation of the mixture for 4 hours a t 55"; this gave a 77 % yield of the 4-0-acetyl-6-0-trityl derivative. Tosyl esters of sugars having a free reducing group can be transformed without causing to the phenylhydra~onela~ and p-nitrophenylhydrazonez'J'J desulfonylation. Although, under certain conditions (see p. 167), sulfonyl or sulfonyloxy groups may be removed in an alkaline environment, carboxylic ester groupings (e.g., 0-acetyl and 0-benzoyl) may often be detached without much (or without any) accompanying desulfonylation. Thus, an 80% yield of methyl 6-O-tosyl-cr-~-glucopyranosidere~ulted27~ when a solution of its 2,3,4-tribenzoate (prepared via the 6-0-trityl derivative) in absolute methanol was saturated at 0" with dry ammonia and then kept a t room temperature for 4 days. Similarly, deacetylation20'Jmay be brought (274) R. Allerton and W. G. Overend, J . Chem. SOC.,1480 (1951). (275) B. Helferich and Johanna Becker, Ann., 440,1 (1924).
160
R. STUART TIPSON
about; thus, a 75 % yield of methyl 2-0-tosyl-@-~-ghcopyranosidewas obtainedaTBfrom its 3,4,6-triacetate. On adding one molecular equivalent of 0.33 N barium hydroxide to a warm solution of 1,2-0-isopropylidene-3-O-tosyl-~-g~ucose 5,6-carbonate in 50% (by vol.) aqueous ethyl alcohol, almost the theoretical yieldIB4of 1,2~-isopropy~dene-3-~-tosyl-~-glucofuranose (plus a small amount of 1,2-0-iaopropy~dene-~-g~ucofuranose) was obtained. A similar procedure was appliedaT7to preparation of 1,2-0-isopropylidene-3-O-tosylD-xylofuranose from its 5-O-carbomethoxy derivative. By the action of aqueous acetone containing sodium hydroxide, only the acetyl and acetoxymethyl groups were removed180 from 3-O-acetoxymethyl-5-O-acetyl2,4-0-methylene-l-0-tosyl-~,~-xylitol after preservation at 20" during 5 hours (yield, 92 %). Similar treatment27sof methyl 4,6-0-benzylidene2-0-tosyl-3-0-trifluoroacety~-a-~-g~ucoside hydrolyzes off only26sthe tri~luoroacetylgroup. By keeping a solution of methyl 4,6-O-benzylidene3-0-carbethoxy-2-0-tosyl-ar-~-galactoside in aqueous methanol containing potassium carbonate, during 20 hours a t 18", a 95% yield162of the de-carbethoxylated compound results, with no appreciable detosylation occurring. Often, sodium methozide, cautiously employed, accomplishes similar deacylations. Either of two methods may prove applicable. I n one, a solution of one molecular equivalentaT9of sodium methoxide in absolute methanol is cooled to -10" and added, with shaking, to a similarly cooled, chloroform solution of the compound to be deacylated. After shaking at -10" for a short time, the reaction is arrested by cautious addition of ice-water, followed by neutralization with acetic acid. I n the other procedure, a catalytic arnountz8O(e.g., one six-hundredth t o one thirtieth of the theoretical quantity) of sodium methoxide is employed; the reaction may then often be performed, in the absence of chloroform, at room temperature, or even under reflux. Examples of successful use of the low-temperature procedure include the deacetylation of: 1,2,3,6tetra-0-acetyl-4~-tosyl-D-glucose;281 methy184*2'6(and benzylE4) 3,4,6tri-0-acetyl-2-O-tosyl-/3-~-glucoside (but if the deacylation of the methyl glycoside is performedS54at 0", the product isa8*methyl 2,3-anhydro(276) E.W.Bodycote, W. N. Haworth, and E. L. Hirst, J. Chem. Soc., 151 (1934). (277) W. N. Haworth, C. R. Porter, and A. C. Waine, Rec. trav. chim., 67, 541 (1938). (278) E.J. Bourne, Mrs. Clarice E. M. Tatlow, and J. C. Tatlow, J . Chem. Soe., 1367 (1950). (279)G.Zemplh, Ber., 69, 1254 (1926). (280) G.Zomplh and E. Paosu, Ber., 02, 1613 (1929). (281)B. Helferich and W. Klein, Ann., 466, 173 (1927). (282) W.H.G.Lake and S. Peat, J . Chem. Soe., 1417 (1938).
SULFONIC ESTERS OF CARBOHYDRATES
161
8-D-mannoside) ; phenyl 2,3,4-tri-0-acetyl-6-O-tosyl-~-~-glucoside~~~ (in which contrast to pheiiyl 2,3,6-tri-0-acety~-4-O-tosy~-~-~-g~ucoside,~~~ gave only a 7 % yield (isolated) of phenyl 4-O-tosyl-p-~-glucoside, but a 22% yield of a phenyl anhydro-p-D-hexoside); the t r i a c e t a t e ~of~ ~ ~ vanillin 2-, 3-, and 4-O-tosyl-p-~-glucoside; methyl 2,3,6-tri-O-acetyl4-O-mesyl-p-~-glucoside;~~* phenyl 2,4,6-tri-0-acety~-3-o-mesyl-fl-~-glucoside;lY0andzs4hepta-0-acetyl-6-0-mesyl-trehalose. Catalytic deacetylation at room temperature was successfully applied to methyl 2,3,4-triO-acetyl-6-O-tosyl-c-~-glucoside~~~ and -p-~-galactoside.143 Similar catalytic debenzoylation has been accomplished.79~214~223 Catalytic deacetylat o 15267minutes under reflux has als023-208~23y found use. tion during was employed for Catalytic deacylstioii with barium (in 88% preparation of 1,2-O-isopropylidene-3-0-tosy~-~-xylofuranose~~~ yield) from its 5-0-benzylcarboxy derivative, and of methyl 3-0-tosylP-D-glucopyranosideZz6from its 2,4,6-triacetate (with, however, about 25% ' detosylation).
IV. REDUCTIVE DESULFONYLATION AND DESULFONYLOXYLATION 1. The Use of Sodium Amalgam Shortly after the preparation l6 of 1,2:5,6-di-O-isopropylidene-3-0tosyl-D-glucose had been described, Freudenberg and Brauns17discovered that detosylation to the parent 1,2:5,6-di-0-isopropylidene-~-glucose is readily achieved by treating an ice-cold solution of the ester (in 80% aqueous ethanol) with an excess of 2% sodium amalgam, added in portions, and then keeping the mixture at room temperature during 24 hours. In this way, the tosyl group was split off and converted to p-toluenesulfinic acid (sodium salt), which was isolated and characterized:
(283) B. Helferich and F. Strauss, J. prakt. Chem., 142, 13 (1935). (284) B. Helferich and F. von Stryk, Ber., 74, 1794 (1941). (285) W. N. Haworth, L. N. Owen, and F. Smith, J. Chem. Soc., 88 (1941). (286) H. S. Isbell, Bur. Standards J . Research, 6, 1179 (1930); cf., W. Weltzien and R. Singer, Ann., 445, 71 (1925). (287) P. A. Levene and R. S. Tipson, J . Biol. Chem., 93, 631 (1931).
162
R. STUART TIPSON
TABLEI Some Compounds Reductive1y Desulfonylated with Sodium Amalgam Compound
References
134 1,2-O-Isopropylidene-5-O-tosyl-~-arabinose 229 1,2-O-Isopropylidene-3-O-methyl-5-0-tosyl-~arabinose 17 1,2:5,6-Di-O-isopropylidene-3-O-tosyl-~-glucose 225 Methyl 2,4-di-0-methyl-3-0-tosyl-fl-~-glucoside 146 Methyl 4,6-0-ben~ylidene-3-0-methyl-2-O-tosyl-~-~-glucos~de 245 Ethyl 2,3,6-tri-0-methyl-5-O-tosyl-~-~-glucos~de 234 Methyl 2,3,6-tri-0-methyl-5-0-tosyl-c~-~-glucoside 234 Methyl 2,3,6-tri-0-methyl-5-0-tosyl-j3-~-glucoside 245 2,3,6-Tr~-0-methyl-5-~-tosyl-fl-~-glucosyl-trimethylammon~um chloride 265 2,3-O-Isopropylidene-1,6-di-0-tosyl-~-fructose 265 6-Deoxy-2,3-~-~sopropy~~dene-1-O-tosyl-~-fructose 288 5,6-Anhydro-l,2-0-isopropylidene-3-O-tosyl-cidose 289 Methyl 4,6-0-bensylidene-3-deoxy-2-0-tosyl-~-~-"mannoside" 290 Methyl 6-deoxy-2,3-0-isopropylidene-4-O-tosyl-~mannoside 290 Methyl 6-deoxy-2,3-0-isopropylidene-5-O-tosyl-~-mannoside 220 Methyl 6-deoxy-2,3-di-0-methyl-4-0-tosyl-ar-~mannoside 150 Methyl 4,6-0-bensylidene-2-0-methyl-3-0-tosyl-~-~-galactoside 268 Methyl 6-deoxy-3-0-methyl-2,4-di-O-tosyl-fl-~-galactoside 220 Methyl 6-deoxy-3,4-di-0-methyl-2-0-tosyl-~~-~-galactoside 270 Methyl 2,6-dideoxy-3-0-methyl-4-0-tosyl-a-~-"galactoside " 222 Methyl 6-deoxy-2,3-O-~opropylidene-5-0-tosyl-~-a1los~de 291 Methyl 2,6-dideoxy-4-0-tosyl-~~-~-"rtlloside I' 269,291 Methyl 2,6-dideoxy-3-0-methyl-4-O-tosyl-c~-~-"alloside " Methyl 4,6-O-hexahydrobenzylidene-3-O-methyl-4-O-tosyl-~~-~-altroside267 267 Methyl 6deoxy-3-0-methyl-2,4-di-O-tosyl-~~-~-altroside 292 1,6-Anhydro-3,4-0-~opropylidene-2-0-tosyl-~-~-altrose 271 Methyl 2,6-dideoxy-3-0-methyl-4-0-tosyl-~~-~-zylo-hexoside 271 Methyl 2,6-dideoxy-3-0-methyl-4-0-tosyl-~-~-sylo-hexoside 264 6-Deoxy-2,3-0-isopropylidene-l-0-tosyl-~-sorbose 170 2,4:3,5-Di-0-methylene-l-0-tosyl-~-epirhamnitol
The reaction has since been extensively employed, with only such ~ 3 ~ ~ ~ of 80% minor modifications as use of 80% m e t h a n 0 1 ~ ~(instead ethanol) and 4 %222,290 sodium amalgam, and and passing in of carbon dioxidezs8during the reduction. Some of the compounds to which the method has been successfully applied are listed in Table I; this constitutes impressive evidence as t o the value of the method. However, it should be noted that, if the sulfonyl groups are so situated (288) A. S. Meyer and T.Reichstein, Helv. Chim. Acta, 29, 152 (1946). (289)H.R.Bolliger and D.A. Prins, Helv. Chim. Acta, 29, 1061 (1946). (290) P.A. Levene and J. Compton, J . A m . Chem. SOC.,67, 2306 (1935). (291) H.R. Bolliger and P.Ulrich, Helv. Chim. Acta, 86, 93 (1952). (292)F.H.Newth and L. F. Wiggins, J . Chem. SOC.,1734 (1950).
SULFONIC ESTERS OF CARBOHYDRATES
163
and disposed as to permit of anhydro-ring formation (see p. 172) by dehydrogenation-desulfonyloxylation, such formation may occurzg3to some extent. Thus, sodium-amalgam reduction of 2,5-anhydro-l-Otosyl-L-iditol during 3 days gavez33the expected 2,5-anhydro-~-iditol plus a dianhydrohexitol. 1,2-O-Isopropylidene-6-O-tosyl-~-glucofuranose gavezg3a 40 % yield of the expected 1,2-O-isopropylidene-~-ghcofuranose plus an oily product of unidentified character; and reduction in presence of carbon dioxide afforded a 70 % yield of 5,6-anhydro-1,2-0isopropyhdene-D-ghcofuranose. Finally, 1,2-O-isopropylidene-5,6-di-Otosyl-D-glucose yielded29a3,6-anhydro-1,2-0-isopropylidene-5-0-tosyl-~glucose plus a trace of unidentified product, and, in presence of carbon dioxide, an almost quantitative yield of unchanged starting-material was recovered. 2. T h e Use of Raney Nickel Under appropriate conditions, Raney nickel can also cause reductive desulfonylation (compare, p. 156). Two proceduresz84 have been worked out, both involving, for tosyl esters, the over-all reaction:
+
RO4302C~Hr Nix(H)2
+ 2 H2
-+
ROH
+ Ni,(S) + C,Ha + 2 H 2 0 .
The first method employs, per unit weight of substance to be desulfonylated, about 5 times the weight of Raney nickel; the reduction is conducted at room temperature in absolute ethanol, with hydrogen at (or slightly above) atmospheric pressure. Except with the benzylsulfonic esters studied, poisoning of the catalyst, by attachment of sulfur thereto, slows the reaction markedly. Two molecular proportions of hydrogen are absorbed per sulfonic group and, in favorable cases, the reaction is completed in 0.5 to 2 hours. The second method, essentially that of Mozingo and involves boiling with ethanol, diethyl ether, or cyclohexane plus a similar large excess of reduced Raney nickel, under reflux for many hours, and is usually less satisfactory. Applicationzg4of the first method to 1,2 :5,6-di-O-isopropylidene-3-0tosyl- or -3-0-benzy~sulfonyl-~-glucose and to 1,2:3,4-di-O-isopropylidene6-O-benzylsulfonyl-~-galactose gavezg4the following yields (time, in parentheses) of corresponding desulfonylation product: 96 % (2 hrs.) ; 100% (0.25 hr.); and 95% (0.25 hr.). Treatment of 1,2,3,4-tetra-Oacetyl-6-O-benzylsulfonyl-/3-~-glucose during 0.15 hour gave294an oil from which some penta-0-acetyl-/3-D-glucopyranose was obtained on acetylation. The second procedure, appliedzg4to 1,2:5,6-di-O-isopropyIi(293) L. von Vargha, T. PuskBs, and E. Nagy, J . Am. Chem. Soc., 70, 261 (1948). (294) G. W. Kenner and M. A. Murray, J . C'hem. Soc., 5178 (1949). (295) R. Mozingo, D. E. Wolf, S. A. Harris, and K. Folkers, J . Am. Chem. Soc., 66, 1013 (1943).
184
R . STUART TIPSON
dene-3-0-tosyl- or -3-0-benzy~sulfony~-~-glucose during 3 hours, and to during 7 hours gavezs4 1,2 :3,4-di-0-isopropylidene-6-0-tosyl-~-galactose satisfactory yields of the expected desulfonylation products. When, however, these methods were triedzg4with compounds capable of transformation to anhydro-sugars by desulfonyloxylation-dehydrogenation (see p. 172), only small yields of the expected products were obtained, although the products were free from sulfur. Thus, 1,2-O-isopropylidene6-0-tosyl- and -5,6-di-0-tosyl-~-glucose gavezg4(in 24 hours) 39 % and 25 % yields, respectively, of 1,2-0-isopropy~idene-~-g~ucofuranose; and methyl 2-O-tosyl-a-~-arabinoside aff ordedzg4a 30 % yield of methyl a-L-arabinoside after 7 hours under reflux. 3. The Use of Lithium Aluminum Hydride Finally, lithium aluminum hydride is a valuable reagent for desulfonylation or desulfonyloxylation. With this reductant, in boiling benzene,z98ether,z91,z96 or tetrahydrofuranlZg1 reductive splitting is sometimes slow but, apparently, always occurs. A primary tosyloxy group of an aldose derivative is readily removedzg1to give, by alkyl-oxygen fission, the corresponding w-deoxy derivative pluszg8p-toluenesulfonic R j OSOzR‘
-+
RH
+ R’SOzH
acid; a secondary tosyl group is split off less readily,z91with formation (by acyl-oxygen fission) of the corresponding, free secondary alcoholic group pluszg8 p-toluenesulfinic acid. Thus, 1,2:3,4-di-O-isopropyliRO j SOZR’ -+ ROH
+ R’SOZH
dene-6-0-tosyl-~-galactose giveszg66-deoxy-1,2 :3,4-di-O-isopropylideneD-galactose (6-deoxy-~-galactose = D-fucose), and, after treatment in boiling tetrahydrofuran for only SO minutes, methyl 3-0-methyl-2,4,6~~ 6-deoxy-3-0-methyl-2,4-di-Otri-0-tosyl-P-D-idoside aff0 1 - d ~ methyl tosyl-p-D-idoside. Moreover, treatment of methyl 4,6-O-benzylidene3-0-methyl-2-0-tosyl-a-~-altroside during 1 hour is without much effect,291and refluxing for SO hours is required for production of a quantitative yieldzg1 of methyl 4,6-0-benzylidene-3-O-methyl-a-~-altroside. Similarly, 1,2:5,6-di-O-isopropylidene-3-0-tosyl-~-g~ucose is merelyz98 detosylated. On the other hand, 2,3:4,5-di-0-isopropylidene-l-0-tosylD-fructose is also simply detosylated; this is a further example of the special properties of 1-0-tosyl-ketose derivatives (see p. 190). An interesting application of stepwise reduction is the following. (296) H. Schmid and P. Karrer, Helv. Chim. Ada, 32, 1371 (1949).
SULFONIC ESTERS OF CARBOHYDRATES
165
Treatment of methyl 2,3-anhydro-4,6-di-O-tosyl-a-~-alloside with a boiling solution of lithium aluminum hydride in tetrahydrofuran for only one hour aff ordsZg1methyl 4-O-tosyl-a-~-digitoxoside, by simultaneous opening of the anhydro-ring (at carbon atoms 2 and 3) and detosyloxylation at carbon atom 6 : HbOCH3 I
1
HCOCHa I
But if the treatment, with about 3 times as much lithium aluminum hydride, is prolonged for 6 hours there resultszg1a 70% yield of methyl a-D-digitoxoside; with ether as solvent, a reaction time of 15 hours was necessary.
V. ACTIONO F SOMEALKALINEREAGENTSON SULFONIC ESTERS Much of the development in this field is traceable to two quite different original interests. The first goes back to Ullmann and NBdai's observationz7 that the p-toluenesulfonate of 2,4-dinitrophenol, like 2,4-dinitrochlorobenzene, reacts with amines; these cause desulfonyloxylation. For example, with aniline, the following reaction occurred :
Soon after the application of sulfonylation to sugar derivatives, the action and of hydrazinel7 on 1,2:5,6-di-O-isopropylidene-3-0-tosyl-~-glucose, of ammoniazg7on 1,2 :3,4-di-0-isopropylidene-6-0-tosyl-~-galactose, was found to proceed similarly. Immediate application of this principle to preparationz98 of "aminated" cellulose d e r i ~ a t i v e s ,of~ ~possible ~~~~ (297) K . Freudenberg and A. Doser, Ber., 68, 294 (1925). (298) P. Karrer, British Pat. 249,842 (1025); Chem. Abstracts, 21, 1019; British Pat. 263,169 (1925); Chem. Abstracts, 22, 171; German Pat. 438,324 (1925); Chem. Centr., 98, I, 1391 (1927); German Pat. 459,200 (1925); Chem. Centr., 99, I, 3115 (1928). (299) P. Karrer and W. Wehrli, Helv. Chim. Acta, 9, 591 (1926); Teztile World, 71, 2031 (1927).
166
R. STUART TIPSON
industrial value because of their affinity for acid dyes, greatly stimulated activity48(d) 4 8 ( c ) 56.67,81.105,106,300 in the field. The second kind of investigation derives from a speculation by Robinson,301in 1927, that the sugar-ester moiety in pentose-nucleic acids302is really that of D-XylOSe 3-phosphate1 and that, on hydrolysis of the nucleic acid, this undergoes a Walden inversion at carbon atom 3 to give the D-ribose which is actually isolated. To test the validity of this hypothesis, Levene and coworkers examined the behavior of a variety of sugar phosphates on hydrolysis and decided that Walden inversion never occurs. I t is now believed that, if such sugar interconversions ever occur in Nature, they probably proceed via sugar sulfates. Studies on the mechanism of alkaline hydrolysis, e.g., using water made from heavy oxygen, show that phosphates behave like carboxylic esters, with rupture at the P-0 linkage: I
I
RO~PO~H~ -+ R0.H H~OI~H
+
+ HzPOa0’8.
In the course of some of these investigations, the behavior of sulfonic esters of carbohydrates (on alkaline hydrolysis) was studied, laying the foundation for the extensive knowlege on this subject which has gradually been accumulated. 1. Reaction with Alcoholic Alkalis or with Sodium Methoxide
a. Desulfonylation at the “Isolated” Primary Sulfonyloxy Group.-If only the primary hydroxyl group of an aldose sugar derivative is esterified by a sulfonic acid, and all the other hydroxyl groups are protected by substituents not hydrolyzable by alkali (e.g., methyl or isopropylidene groups), so that the compound may be regarded as the substitution product of an opticably-inactive monohydric alcohol, the “isolated ” w-sulfonyl group is removed on treatment with alkali, giving the effect of an acyl-oxygen fission (see p. 110). However, some of the related glycoseen derivative may be simultaneously formed, presumably by simultaneous alkyl-oxygen fission and dehydrogenation; this is com(300) I. Sakurada, Bull. Znst. Phys. Chem. Research (Tokyo), 8, 265 (1929); T. Nakashima and I . Sakurada, ibid., 8, 272 (1929); Chem. Abstracts, 23, 3572. V . R. Hardy (to E. I. du Pont de Nemours & Co.) U. S. Pat. 2,136,296 (Nov. 8, 1938); J. F. Haskins (to E. I. du Pont de Nemours & Co.) U. S. Pat. 2,136,299 (Nov. 8, 1938); Chem. Abstracts, 33, 1495. (301) R. Robinson, Nature, 120, 44, 656 (1927). (302) R. S. Tipson, Advances in Carbohydrate Chem., 1, 193 (1945). (303) J. B. M. Herbert and E. Blumenthal, Nature, 144,248 (1939); E. Elizabeth Percival and E. G. V. Percival, J. Chem. Soc., 874 (1946).
SULFONIC ESTERS O F CARBOHYDRATES
167
parable with the formation of camphene from borne01 p-toluenesulfonate (and of ASmenthene from menthol p-toluenesulfonate) by the action of pyridine (see p. 126). For example, treatment of 1,2:3,5-di-O-isopropylidene-6-0-tosyl-~-glucose with either alcoholic sodium hydroxide or sodium methoxide solution (under reflux) giveslgl 1,2:3,5-di-O-isopropylidene-D-glucose plus some 1,2 :3,5-di-0-isopropylidene-~-glucoseen-5,6 : HCO,
HCO
HCO,
Hb0/Ip
HbO)"
H&O/IP
+
/O&H
I
+
/OhH
Similarly, action of alcoholic potassium hydroxide on 2,3:4,5-di-O-isopropylidene-l-0-tosyl-D-fructose during 2 days at 37”gave163some 2,3:4,5di-0-isopropylidene-D-fructose (plus a large proportion of unchanged starting mterial). Occurrence of such desulfonylation in alkaline solution permits use of sulfonic esters as alkylating agents, as previously mentioned (see p. 112), R’SOzOR
+ R”0Na -+
R OR”
+ R’S08Na,
provided that cleavage of the ester is reasonably facile. However, sulfonic esters of some sugars, e.g., methyl 3,4-0-isopropylidene-2-0methyl-6-0-tosyl-a-~-galactoside, are very stable212to alkaline hydrolysis; 6-sulfonic esters of galactose are also very stable to sodium iodide (see p. 185). b. Desulfonylation at a n “Isolated ” Secondary Sulfonyloxy GroupDepending on the conditions, hydrolysis of a carboxylic ester of a n optically-active, monohydric alcohol can take place304 with or without Walden inversion, but the latter seems to he much the more common. In contrast, alkaline hydrolysis of sulfonic esters of such alcohols usually results305in Walden inversion; this effect is, of course, only to be expected when the G O bond is ruptured. Thus, using for alkaline hydrolysis of the esters a specimen of water in which the oxygen was the isotope of (304) J. Kenyon, Bull. soc. chim. France, 1061,C64; E. D. Hughes, ibid., 1961,C17. (305) (a) H. Phillips, J . Chem. Soc., 123, 44 (1923); (b) J. Kenyon, H. Phillips, and H. G. Turley, ibid., 127, 399 (1925); (c) A. J. H. Houssa, J. Kenyon, and H. Phillips, ibid., 1700 (1929); (d) J. Kenyon and H. Phillips, Trans. FaTaday SOC.,26, 451 (1930); (e) J. Kenyon, H. Phillips, and F. M. H. Taylor, J . Chem. SOC.,173 (1933); (f) J. Kenyon, H. Phillips, and Valerie P. Pittman, ibid., 1072 (1935); (g) E. D. Hughes, Trans. Faraday Soc., 34, 202 (1938).
168
R. BTUART TIPSON
mass 18, a carboxylic ester gaveao6an alcohol containing no 01*,but the acid contained Ole: RO-;-CO-R”
+ H--~-O’~H + ROH +
~ ” ~ 0 0 1 8 ~ .
On hydrolyzing a! sulfonic ester, the following reaction occurred : R-;-OSO~R’
+ HO~~-:--H
-+
~
0
1
+ R’SO~H. 8
~
Now, when one secondary hydroxyl group of a sugar is esterified by a TABLE I1 Some Alkaline Hydrotyses of a Secondary Sulfonyl Group, without Walden Inversion Compound
Reagent
References
5-Deoxy-l,2-0-isopropylidene-3-O-tosyl-~-xylose KOH-aq. MeOH 263 1,2-O-Isopropylidene-5-0-methyl-3-0-tosyl-~xylose 307 Methyl 2,5-di-0-methyl-3-0-tosyl-a-~-xyloside KOH-aq. EtOH 223 Methyl 2,5-di-0-methyl-3-0-tosyl-~-~-xyloside 223 KOH-aq. EtOH Methyl 2,3-0-isopropylidene-5-0-tosyl-~ rhamnosidea 290,307,308 KOH-aq. MeOH Methyl 2,3-0-isopropylidene-4-O-tosyl-~rhamnoside KOH-aq. MeOH 290 Methyl 3,6-anhydro-4-0-methyl-2-0-tosyl-aD-galactoaide 144 NaOH-aq. EtOH Methyl 4,6-0-bensylidene-3-0-methyl-2-0tosyl-a-n-galactoside MeONa-MeOH 309 Methyl 2,4,6-tri-0-methyl-3-O-tosyl-rw-ogalactoside MeONa-MeOH 125, 212 Methyl 2,4,6-tri-0-methyl-3-0-tosyl-(3-~galactoside MeONa-MeOH 212 3,6-Anhydro-1,2-0-isopropylidene-5-O-tosyl-~glucose NaOH-aq. EtOH 75 Methyl 2,3-di-0-methyl-4-0-tosyl-6-0-trityl-a-~~ MeONa-MeOH-CaHB glucoside 155 Methyl 2,3,6-tri-O-met hyl-4-0-phenylsulf onyl19-D-glucoside 20 Methyl 2,3,6-tri-O-methy1-4-0-tosyl-a,(3-~glucoside MeONa-MeOH 82 Methyl 3,4,6-tri-0-methyl-2-0-tosyl-@-~MeONa-MeOH glucoside 254 0 Gives a 9 0 4 5 % yield of the corresponding glyooseen-6,6 (together with some of ‘the expected methyl 2,3-0-isopropylidene-~rhamnofuranoside).
(306) (307) (308) (309)
M. Polanyi and A. L. Ssabo, Trans. Faraday SOC.,80, 508 (1934). P. A. Levene and J. Compton, J . Am. Chem. SOC.,67, 777 (1935). I. E. Muskat, J . Am. Chem. SOC.,66, 2653 (1934); 67, 778 (1935). C. Tamm, Helv. Chim. Acta, 84, 163 (1949).
SULFONIC ESTERS O F CARBOHYDRATES
169
sulfonic acid, and all the other hydroxyl groups are protected by substituents not hydrolyzable by alkali, hydrolysis at the secondary sulfonyl group may be difficult but, if achieved, proceeds by acyl-oxygen fission, involving no Walden inversion. Thus, in 1922, Freudenberg and coworkers that 1,2:5,6-di-0-isopropylidene-3-0-tosyl-~-glucose is “extraordinarily stable” on treatment with concentrated alcoholic alkalis, even when heated; by boiling a 5 % solution in 2.5 N potassium an almost quantihydroxide (in 50% ethanol) for 7 hours it affords166J07 tative yield of 1,2:5,6-di-0-isopropylidene-~-glucose.Other examples of this kind of desulfonylation are listed in Table 11; it has proved valuable in synthetic studies. It was claimed308that alkaline hydrolysis of methyl 6-deoxy-2,3-O-isopropylidene4-0-tosyl-~mannoside (I) gives, by Walden inversion a t carbon atom 4, “methyl 6-deoxy-2,3-0-isopropylidene-~talopyranoside ” (11) ; and that alkaline hydrolysis of methyl 6-deoxy-2,3-0-isopropylidene-5-O-tosyl-~-mannoside (111) yields,808 by ” inversion a t carbon atom 5, “methyl 6deoxy-2,3-0-isopropylidene-~-gulofuranoside (IV) plus methyl 6-deoxy-2,3-O-isopropylidene-~rnannosid-5,6-een (C). The formation of C has since been confirmed,a80 but IV was shown to be290~307actually methyl 6-deoxy-2,3-O-isopropylidene-~mannofuranoside ( B ) , and I1 is indeed methyl 6~eoxy-2,3-O-isopropylidene-~mannopyranoside ( A ) . Thus, this claim to discovery I H O M e
CH3 I E H O M e
c:
TsO H
A
17HOMe
A
HO H
riHOMe
AH
II
AH3
AH3
CH2
I11
B
C
of Walden inversion on alkaline desulfonylation a t an isolated secondary sulfonyl group of a sugar derivative has been disproved.
Desulfonylation without Walden inversion also occurs with com-
170
R. STUART TIPSON
pounds having hydroxyl groups which are free (or substituted by alkalilabile groups, e.g., acetyl), provided that these hydroxyl groups are not in suitable spatial proximity to permit of anhydro-ring formation. Thus, r e a ~ t i o nof~ 5,6-di-0-acetyl-1,2-O-~sopropylidene-3-O-tosyl-~-glucose ~~,~~~ with boiling aqueous acetone containing sodium hydroxide, during 5 hours, gave an 83 % yield140of 1,2-0-isopropy~dene-~-glucofuranose; and the same product r e s ~ l t e d ~in* ~almost * ~ ~ ~quantitative yieldlE9 from (and similar treatment of 1,2-O-isopropylidene-3-O-tosy~-~-glucofuranose 3-su1fate3l0). Similarly, 6-0of 1,2-O-isopropylidene-~-g~ucofuranose benzoyl-l,2-0-isopropylidene-5-0-methyl-3-0-t osyl-D-glucose afforded lS9 1,2-0-isopropylidene-5-O-methyl-~-glucose, thus providing a route to the synthesis of 5-O-methyl-~-glucose. I n the same way, methyl 2,3-di-0-methyl-4-0-tosyl-a-~-glucoside gavelKK methyl 2,3-di-O-methyla-D-glucoside plus a small proportion of a supposed glucoseen derivative, together with much unchanged starting material. c. Desulfonyloxylation at a “Non-isolated” Primary Sulfonyloxy Group.311-1n contrast to the foregoing behavior, if the o-sulfonyl-aldose derivative bears an appropriately placed hydroxyl group which is free (or substituted by an alkali-hydrolyzable group), alkaline hydrolysis leads to establishment of a n anhydro-ring, through transitory formation of a carbonium cation (see p. 172), by desulfonyloxylation, with dehydrogenation. For such ring-formation, it is necessary that the sulfonyl group be spatially vicinal to, and on the same side of the sugar ring as, the free (or potentially free) hydroxyl group; this circumstance may not always be apparent in the Fischer projection formula, but will be evident on inspecting the Haworth formula of the compound. I n the aldohexoses having a protected hydroxyl group at carbon atom 6 , two cases require consideration. First, there is the aldohexofuranose with a free (or potentially free) hydroxyl group a2 carbon atom 3; this gives the corresponding 3,6-anhydro-hexofuranose. For example, treatment of 1,2-0-isopropylidene-5,6-di-0-tosyl-~-glucose (which has a difficultly hydrolyzed, secondary tosyl group) with boiling, aqueous ethanol containing sodium hydroxide, during 2 hours, g i v e ~ 7 ~a ~76~ to 3 ~90% yield the same prodof 3,6-anhydro-l,2-0-isopropylidene-5-O-tosyl-~-glucose; uct may be prepared3’$ by using the chloroform-methanol-sodium methoxide technique (10 minutes at - 10’). It is the compound obtained (310) E. G. V. Percival, J . Chem. Soc., 119 (1945). (311) S. Peat, “The Chemistry of Anhydro Sugars” in Advances in Carbohydrate Chem., 2, 37-77 (1946). The next two sections (V Ic and V Id, on formation of anhydro sugars) briefly cover, from a somewhat different point of view and with the minimum of duplication, a mass of information which has been authoritatively discussed b y this author (who gave references to the end of 1944). (312) H. Ohle and L. von Vargha, Ber., 62, 2435 (1929).
SULFONIC ESTERS O F CARBOHYDRATES
171
by Ohle and D i c k h a ~ s e on r ~ ~treating 1,2-0-isopropy~idene-~-g~ucofuranose with excess p-toluenesulfonyl chloride in boiling pyridine-chloroform (see p. 117). The same 3,6-anhydro ring results if the hydroxyl group at position 3 is free and that at position 5 is engaged as the pyranoside. The following are some examples discovered since3111944: (with sodium hydroxide) : methyl 3,6-anhydro-a-~-mannopyranoside from’73 methyl 2,3,4-tri-0benzoyl-6-0-tosyl-a-~-mannoside (using aqueous methyl Cellosolve as solvent); methyl 3,6-anhydro-2-0-tosyl-/3-~-glucoside from237 methyl 3,4-di-0-acetyl-2,6-di-0-tosyl-~-~-glucoside (aqueous acetone as solvent) ; and methyl 3,6-anhydro-2-0-mesyl-cu-~-galactoside from169methyl 2,G-di0-mesyl-a-D-galactopyranoside; (with sodium methoxide and then sodium hydroxide) : methyl 3,6 :3‘,6’-dianhydro-@-maltosidemonohydrate from313 (a1so3l4the analogous methyl penta-0-acetyl-6,6’-di-O-mesyl-/3-maltoside methyl dianhydro-8-cellobioside). [Similar results are obtained with hexitols in which position 5 is already engaged with position 1; thus, 1,5-anhydro-2,3,4-tr~-0-benzoyl-6-0-tosyl-~-mannitol givesal6 1,5:3,6-dianhydro-D-mannitol (“neomannide”), and 1,5-anhydro-2,3,4-tri-O-benzoy~-6-0-tosy~-~-galactito~ yields3141,5:3,6-dianhydro-~-galactitol.]3 ,GAnhydro-hexoses are also preparable311 from their appropriately substituted w-deoxy-w-halogeno derivatives, w-sulfates, and w-nitrates. Since the w-carbon atom is not asymmetric, none of the above transformations can involve Walden inversion. In aldohexofuranoses having a jree (or potentially free) hydrozyl group at carbon atom 5 , alkaline hydrolysis proceeds readily (e.g., with cold sodium methoxide), with loss of the elements of water and resultant formation of an ethylene-oxide ring between3“ carbon atoms 5 and 6. Indeed, even if other hydroxyl groups are also available for ring formation, the ethylene-oxidic ring is formed preferentially. 5,6-Anhydrohexoses are also preparable311 from appropriate w-deoxy-w-halogeno derivatives and inorganic w-esters of sugars. Thus, alkaline hydrolysis of barium 1,2-0-isopropylidene-3-O-methyl-~-glucofuranose 6-sulfate affords316 5,6-anhydro-1,2-0-isopropylidene-3-O-methyl-~-glucose. Because carbon atom 6 is not asymmetric, the 5,ganhydro sugars possess the configuration of the parent sugar. d. Desulfonyloxylation at a Non-isolated ” Secondary Sulfonyloxy Gro~p.~l’-If the secondary sulfonyloxy group is trans to a single, con(313) F. H. Newth, s. D. Nicholas, F. Smith, and L. F. Wiggins, J. Chem. SOC., 2550 (1949). (314) H. G . Fletcher, Jr. and C. S. Hudson, J . Am. Chem. Soc., 72, 886 (1950). (315) R. C. Hockett and Elizabeth L. Sheffield, J. Am. Chem. SOC.,68,937 (1946). (316) E. G . V. Percival and R. B. Duff, Nature, 168, 29 (1946); R. B. Duff and E. G. V. Percival, J. Chem. SOC., 1675 (1947).
172
R. STUART TIPSON
tiguous, free (or potentially free) , secondary hydroxyl group, anhydroring formation involving a Walden inversion occurs (e.g., with a tosyl ester) as follows: I
H-C-
I
r----,
.--, I [HjO-C-H
iOJ?ej
,C-H 0 , I
(Inversion) ____c
C-H
I
I
By loss of a proton, the contiguous trans hydroxyl group becomes an anion on the side opposite to the positive charge. Consequently, when the charges neutralize, the hydrogen atom of the carbonium cation is pushed over to the other side; thus, when the oxide ring is formed, by dehydrogenation, there is Walden inversion at the carbon atom which originally bore the sulfonyloxy group, as follows : H-
HO-
bb-H I
-0Ts 3
"-x'
:O-
I
-
I
(Inversion)
I
-H
I
-H
and the oxygen atom of the resulting ethylene-oxide ring is on the other side of the sugar plane. An interesting example, in which there are three oxygen rings, is 1,6:2,3-dianhydro-P-~-talopyranose, formedzo6 by alkaline demesyloxylation-dehydrogenation of 1,6-anhydro-2-0-mesyl0-D-galactopyranose :
(Inversion)
HO~H I
(This dianhydro derivative proved of importance in establishing the configuration of chondrosamine.) The same product results317 on alkaline treatment of 1,6-anhydro-/3-~-galactopyranose 2-sulfate. Contiguous, trans, secondary sulfonyloxy groups, as in17s methyl 2,6-di-0-methyl-3,4-di-O-tosyl-/3-~-glucoside, are often very difficult to hydrolyze. If the secondary sulfonyloxy group is trans to two free (or potentially free), secondary hydroxyl groups, both of which are contiguous to it, two (317) R. B. Duff, J . Chem. Soc., 1597 (1949).
173
SULFONIC ESTERS O F CARBOHYDRATES
products can obviously result on alkaline dehydrogenation-desulfonyloxylation : H+oH [TiOjYH H COH
I
-
I
(Inversion)
HC’I HCOH
I
+
HFoH Hy\() HC’
I
It is not to be expected that these two anhydro compounds should be formed in equimolecular proportions, except in the case of a balanced molecule (e.g., certain sugar alcohols) with the sulfonyloxylated carbon atom situated in the middle. However, if the secondary sulfonyloxy group is cis to one contiguous, free secondary hydroxyl group (or, if feasible, to two), anhydro-ring formation obviously cannot take place with Walden inversion, and so neither anhydro-ring formation nor W a l d e n inversion occurs.311 Such desulfonylations are usually achieved only under drastic hydrolytic conditions. Should the secondary sulfonyloxy group be contiguous to a free, primary hydroxyl group (a situation which arises, for example, in 5-0sulfonyl-aldohexofuranose derivatives) , inversion a t carbon atom 5 can be caused. Thus, L-idose was synthesized288from D-glucose as follows. 1,2:5,6-Di-0-isopropylidene-~-glucose was benzylated and the product cautiously hydrolyzed to the 3-0-benzyl-l,2-O-isopropylidenederivative. Unimolar benzoylation, followed by tosylation, gave 6-0-benzoyl3-O-benzyl-l,2-O-isopropyl~dene-5-0-tosyl-~-glucose which, on alkaline hydrolysis, afforded 5,6-anhydro-3-O-benzyl-l,2-O-isopropylidene-~idofuranose, a compound readily hydrolyzed by acid to give L-idose. D-Allose should similarly be synthesizable from 5-O-tosyl-~-talose. Finally, in regard to predicting the hydrolysis product of a sugar derivative having a secondary sulfonyloxy group vicinal to the free (or potentially free) reducing group, and so substituted in every other position (e.g., with 0-methyl groups) that an anhydro-ring cannot possibly form (but a sugar anhydride could form), there still appearsa” to be some uncertainty. behave similarly, except that the Sulfonic esters of sugar influence of a sugar ring is, of course, absent. The first non-terminal epoxide in the hexitol series was prepared319in 1950. Alkaline hydrolysis of sulfonic esters of other acyclic sugar derivatives (e.g., of aldonic and glycaric acids) has not been extensively investigated. (318) L. F. Wiggins, “Anhydrides of the Pentitols and Hexitols” in Advances in Carbohydrate Chem., 6, 191 (1960). (319) P. Bladon and L. N . Owen,J . Chem. Soc., 604 (1950).
174
R. STUART TIPSON
e. Scission of Anhydro Rings.-The principal value of compounds having anhydro rings liesS1lin the products obtained w h e n the anhydro ring i s ruptured. This scission is usually accomplished rather readily with ethylene-oxide rings, and, if both carbon atoms are secondary, the reaction can obviously proceed in two ways. Thus, if sodium methoxide is the hydrolyst, the methoxyl anion (HaCO-) can approach either of the two secondary carbon atoms involved :
I
HsCO-C-H (Inversion) A
H-
1. I
--OH
and the methoxyl group appears in the product on the side of the sugar plane opposite to where the ethylene-oxide ring had been, Hence, in both product,s, the two new groups (methoxyl and hydroxyl) have the trans configuration; this means that, starting from the original trans grouping (sulfonic ester and hydroxyl group), one of the products has the configuration of the original sugar, but the other has the configuration resulting from a Walden inversion a t both carbon atoms involved. Although two products are always formed, their relative proportions depend on the over-all structure of the anhydro compound. The reaction permits the preparation of new methylated sugars. Similarly, if sodium hydroxide is used for rupture of this kind of ethylene-oxide ring, the products are as follows :
H6
c! "-L>O H-
I
(Inversion)
Na+-
HO-
H-
I h-H H-C-OH cI -OH ! +HO- hI -H
This reaction affords a method for the preparation, from common sugars (usually in good yieId), of sugars which used to be rare. I n the D-aldohexose group, these originally rare sugars are allose, altrose, gulose, idose, and talose. It is obvious that allose cannot be prepared by the above type of reaction (because all its configurational asymmetric groupings are cis to each other) ;it might, however, be synthesized from a 5-0-tosylL-talofuranose derivative (via the Ei,B-anhydro-~-allose derivative).
SULFONIC ESTERS O F CARBOHYDRATES
175
Similar interconversions may be accomplished with appropriate ketoses and sugar alcohols. Scission of 5,6-anhydro-aldohexofuranosesand of four- to sevenmembered anhydro rings (and use of a variety of reagents for such cleavage) has been discussed by Peat.311 2. Reaction with Ammonia and Amines a. Desulfonyloxylation with Ammonia.-If the compound treated with ammonia has an isolated, primary sulfonyloxy group, the corresponding w-amino-w-deoxy derivative is formed. Thus, 1,2:3,4-di-O-isopropylidene-6-0-tosyl-~-galactose yields2g7 6-amino-6-deoxy-l,2 :3,4-di0-isopropylidene-D-galactose on treatment with liquid ammonia at room temperature or with alcoholic ammonia a t 100"; but about 50% of the product is the tetra-0-isopropylidene derivative of the bis-6-deoxy-~ga1actose"imine." Similarly, treatment with saturated methanolic ammonia during 2 hours at room t,emperature readily transforms320 1,2-0-isopropylidene-6-O-tosy~-~-glucofuranose to the corresponding acetal of 6-amino-6-deoxy-~-glucofuranose (N-p-toluenesulfonate). The 1,2:3,5-di-O-isopropylidenederivative results1g1 from 1,2:3,5-di-O-isopropylidene-6-0-tosyl-~-glucose, and is readily deaminated to "isodiacetone-glucose." By-products in the ammonolysis are bis-di-0-isopropylidene-6-deoxy-~-glucose"imine " and 6-deoxy-1,2 :3,5-di-O-isopropylidene-~-glucoseen-5,6. Liquid ammonia, in a sealed tube a t room temperature during 3 weeks, transforms3213,5-0-benzylidene-l,2-O-isopropylidene-6-0-mesyl-~-g~ucoseto the corresponding 6-amino-6-deoxy derivative, in 85 % yield. Similarly, ~-l-O-tosyl-2,3-O-isopropylideneglyceritol affords218the ~-l-amino-2,3-O-isopropylidene derivative of propane-2,3-&01. Should the compound treated with ammonia have an isolated, secondary sulfonyloxy group, the corresponding aminodeoxy derivative is H
L
T
H bI 0 ) I P
b
H 0HbO I
\
(320) H. Ohle and L. von Vargha, Ber., 61, 1203 (1928). (321) B. Helferich and R. Mittag, Ber., 71, 1585 (1938).
176
R. STUART TIPSON
formed, but with greater difficulty. Thus, 1,2:5,6-di-O-isopropylidene3-O-tosyl-~-glucose is substantially unaff ectedl6 by liquid ammonia in a sealed tube at 100” for 24 hours; but by treatment with alcoholic ammonia (saturated a t 15’) during 40 hours a t 172O, the corresponding 3-amino3-deoxy derivativel8 (which, on “deacetonation,” differed from “ epiglucosamine”) was obtained. Likewise, methyl 3,4,6-tri-O-methyl2-O-tosyl-~-~-glucoside affords with the corresponding 2-amino-2-deoxy derivative ;the related D-galactoside behaves206similarly. A “non-isolated” primary sulfonyloxy group in proximity to a potentially free hydroxyl group at carbon atom 3 can give an anhydro ring under mild conditions. Thus, treatment of 1,3,4-tri-O-acety1-2,6-di-O-tosyl-aD-glucose with saturated ethanolic ammonia, during 24 hours a t 20°, aff ~ r d e 3,6-anhydro-2-0-tosyl-/3-~-glucopyranose. d ~ ~ ~ If the secondary suljonyloxy group is not isolated and is trans to a single, contiguous, free (or potentially free) secondary hydroxyl group, the intermediate formation of an anhydro ring occurs (as previously described in reference to anhydro-ring formation with sodium hydroxide and sodium methoxide; see p. 172). Ammonia then causes ring scission as follows: H2N-
“-H-A>”c:
(Inversion)
H+-
t!
H2N H
HAOH
A1 +
t!I
H OH
I
H2N H
For example, treatment of 2,3-anhydro-l,4-dideoxy-erythritol(meso2,3-epoxybutane) with ammonia aff ~ r d s ~ D( ~ -), *L( +)-threo-3-amino2-butanol:
ra 8““ L! Hr
CHs
H
(Inversion)
HA>-
H2N H
H OH
AHS
AH a
D(
-1
+ HaN
H
AH*
L(+)
Of course, if the original molecule is not symmetrical, equimolecular proportions of the two aminodeoxy derivatives will not result. Such conversions of sugars311have been by Stacey. An example is the preparation of methyl 3-amino-3-deoxy-/3-~-altroside (methyl “epiglucosaminide”) in 40% yield from276methyl 3,4,6-tri-O-acetyl(322) W. 0. Cutler and S. Peat, J . Chem. SOC.,782 (1939). (323) F. H. Dickey, W. Fickett, and H. J. Lucas, J . Am. Chem. SOC.,74, 944 (1952). (324) M. Stacey, “The Chemistry of Mucopolysaccharides and Mucoproteins ” in Advances in Carbohydrate Chem., 2, 161-201 (1946).
177
SULFONIC ESTERS OF CARBOHYDRATES
2-O-tosyl-p-~-glucoside, presumably via methyl 2,3-anhydro-p-~-mannopyranoside :
HacoF 1: H OTs
AGO H
(Inversion)
HAOAc
--
(Inversion)
1:
jH NHz HAOH
(LI
H 0-
H 0-
CHzOH
AH.O*e
Such reactions have proved valuable in elucidating the structure of naturally occurring aminosugars, e.g., chitosamine and chondrosamine. Sulfonic esters of sugar alcohols often react similarly with ammonia; and -sorbitol give326the thus, 1,4 :3,6-dianhydro-2,5-di-O-tosyl-~-mannitol corresponding 2,5-diamino-2,5-dideoxy derivatives. However, 1,4:3,6dianhydro-L-iditol aff ords328a compound thought to be 1,4:3,6-dianhydro2,5-dideoxy-2,5-imino-~-mannitol, 6. Desulfonyloxylation with Amines.-As previously mentioned, Ullmann and N&dai27found, in 1908, that alkyl sulfonates, like alkyl halides, can alkylate primary and secondary amines. I n 1922,investigation17 of the behavior of sulfonic esters of sugars commenced with the p r e p a r a t i ~ n 'of ~ ~the ~ ~ 3-deoxy-3-hydrazino derivative (together with some of the 3-deoxy-~-glucoseen-3,4derivative) by action of anhydrous hydrazine a t 140' on 1,2:5,6-di-O-isopropyl~dene-3-0-tosyl-~-glucose. Attention should be drawn to a fascinating conversion said to be undergonez6by the product, on hydrolysis of the isopropylidene groups with hydrochloric acid: N%H
H~OH HA0
\
c1
€1 OH
hH20H
/!H22IP
Replacement can also be caused at a primary carbon atom; thus, 1,2:3,4di-0-isopropylidene-6-O-tosyl-~-galactose reacts l Z 2with anhydrous hydra(325) R. Montgomery and L. F. Wiggins, J. Chem. SOC.,393 (1946). (326) V. G. Bashford and L. F. Wiggins, J . Chem. SOC.,371 (1950).
178
R. STUART TIPSON
zine a t 60" t o give the corresponding 6-deoxy-6-hydrazino derivative plus some of the unsymmetrical bis-(6-deoxy-di-0-isopropylidene-galactose)hydrazine. Hydrazine reacts with methyl 2,3-anhydro-4,6-0-benzylidene-a-D-alloside to give2I4 methyl 2-deoxy-2-hydra~ino-4~6-O-benzylidene-a-D-altroside, and with methyl 2,3-anhydro-4,6-O-benzylidene-a-~mannoside t o give214 methyl 3-deoxy-3-hydra~ino-4~6-0-benzylidenea-D-altroside. Other nitrogenous bases, e.g., dimethylamine,84~1s8~327 behave similarly. Secondary tosyloxy derivatives may give risex6*to unsaturated compounds by dehydrogenation-desulfonyloxylation.
3. Reaction with Alkali-Metal Mercaptides and Sulfides a. Desulfonyloxylation with Allcali-Metal Mercaptides.-In 1925, Gilman and Beaber observed328that alkali-metal mercaptides (e.g., sodium n-butyl mercaptide) desulfonyloxylate simple, primary, alkyl sulfonic esters with formation of the corresponding thio-ether plus sodium p-toluenesulfonate, and Raymond329first applied the reaction to sulfonic esters of sugars in 1934. Thus, treatment of l12-O-isopropylidene5-O-tosyl-~-xylose with potassium methyl (or ethyl) mercaptide in dry acetone at 100" for 2 hours (in a sealed flask) gave 5-deoxy-l,2-0-isopropylidene-5-methylthio- (or -5-ethylthio-)~-xylose in 75 % yield; and 1,2-0-isopropylidene6-O-tosyl-~-glucofuranose with potassium methyl mercaptide in dioxane, during 75 minutes a t 100°, aff ~ r d e d 6-deoxy~~Q 1,2-0-isopropylidene-6-methylthio-~-glucofuranose.Similarly, methyl 2,3-O-isopropylidene-5-O-tosyl-n-ribofuranoside gives33aa 62% ' yield of the corresponding 5-deoxy-5-methylthio derivative; and 9'-(2,3-O-isopropylidene-5-0-tosyl-~-~-ribofuranosyl)-hypoxanthine~~~~~~~ yields, with sodium methyl mercaptide in acetone,332or with potassium methyl mercaptide in dry dimethylformamide, 9'-(5-deoxy-2,3-0-isopropylidene5-methylthio-~-~-ribofuranosyl)hypoxanthine, probably identical with the O-isopropylidene derivative of the nucleoside obtained by deaminating from yeast. Attempts to apply the deoxy-methylthiopentosyl-adenine334 the same reaction for direct synthesis of this adenine nucleoside (by action K. Freudenberg and K. Smeykal, Ber., 69, 100 (1926). H. Gilman and N. J. Beaber, J. Am. Chem. Soc., 47, 1449 (1925). A. L. Raymond, J . Biol. Chem., 107, 85 (1934). W. G. Overend and L. F. J. Parker, Nature, 167, 526 (1951). P. A. Levene and R. S. Tipson, J. Biol. Chem., 111, 313 (1935). K. Satoh and K. Makino, Nature, 167, 238 (1951). J. Baddiley, 0. Trauth, and F. Weygand, Nature, 167, 359 (1951); J. Baddiley, J. Chem. Sac., 1348 (1951); F. Weygand and 0. Trauth, Chem. Ber., 84, 633 (1951). (334) A. L. Raymond, "Thio- and Seleno-Sugars" in Advances in Carbohydrate C h m . , 1, 129-145 (1945). (327) (328) (329) (330) (331) (332) (333)
SULFONIC ESTERS O F CARBOHYDRATES
179
of sodiumaa2or potassiumaaamethyl mercaptide o n a supposed 2,3-0-isopropylidene-5-0-tosyl-adenosine, X ) gave a product which, though allegedly consisting of 5-deoxy-2,3-0-isopropylidene-5-methylthio-adenosine, can at present only be accepted with dubiety in view of the fact that tosylation of adenosine derivatives (to yield compounds of the type of X ) actually give@ N-tosyl-O-tosyl derivatives. Like sodium hydroxide and sodium methoxide, sodium methyl mercaptide merely detosylates an isolated secondary sulfonyloxy group, as in methyl 6-deoxy-3,4-0-isopropylidene-2-0-tosyl-~-~-galactos~de~~~ and methyl 4,6-0-benzylidene-3-O-methyl-2-O-tosyl-t-~-galactoside. ls2 b. Desulfonyloxylation with Alkali-Metal Sulfides.-In 1935, it was notedao6(') that the p-toluenesulfonate of ( -)P-octanol reacts with hydrogen sulfide to give ( --)P-octyl thiol, and that the p-toluenesulfonate of a-benzylethanol, with disodium sulfide in ethanol, yields bis-a-benzylethyl sulfide. Simple dialkyl sulfides and dialkyl disulfides were prepared336by stirring a boiling, saturated aqueous solution of disodium sulfide or disodium disulfide with the alkyl sulfonate, but such reactions have apparently not yet been applied to sulfonic esters of monosaccharides. Disulfide cross-links have been introduced into celluloseaa6 by treating tosylated cellulose acetate with hydrogen sulfide (in pyridine) , or with sodium thiosulfate or thiourea, and then gently oxidizing the product. (Polyvinyl p-toluenesulfonate was similarly treated with thiourea.) The action of disodium sulfide on tosyloxyethyl-cellulose has also*l been studied. 4. Reaction with Other Hydrolysts Soda-lime, finely powdered, intimately mixed with half its weight of 1,2:3,5-di-0-isopropylidene-6-0-tosyl-~-gluco~e, and the mixture heated a t 200" under high vacuum during 30 minutes, transforms the glucose ester intoaa76-deoxy-1,2:3,5-di-0-isopropylidene-~-glucoseen-5,6. Similarly, 1,2:5,6-di-O-isopropylidene-3-O-tosyl-~-glucose givess3* 3-deoxy1,2:5,6-di-O-isopropylidene-~-glucoseen-3,4 (in 68% ' yield) , identical with that obtained" by treating the 3-O-tosyl derivative with hydrazine. The 3-O-mesyl derivative gave only a 4.2 % yield on identical treatment with soda-lime. In the same way, methyl 4,6-0-benzylidene-3-deoxy2-O-tosyl-a-~-mannoside giveszE9methyl 4,6-0-benzylidene-2,3-dideoxya-~-"mannoside"-2,3-een : (335) (336) (337) (338)
F. Drahowsal and D. Klamann, Monatah., 82, 970 (1951). E. F. hard and P. W. Morgan, Znd. Ens. Chem., 41, 617 (1949). H. Ohle and R. Deplanque, Ber., 66, 12 (1933). F. Weygand and H. Wolz, Chem. Ber., 86, 256 (1952).
180
R. STUART TIPSON
CHzO'
Potassium carbonate in aqueous methanol transforms162methyl 4,6-0-benzylidene-3-0-tosyl-a-~-galactoside into methyl 2,3-anhydro4,6-0-benzylidene-a-~-guloside, on boiling under reflux for 15 hours.
VI. ACTIONOF ALKALI-METAL HALIDESON SULFONIC ESTERS In 1897,it was observed88@that potassium iodide (in hot alcohol or acetone) converts ethyl p-bromobenaenesulfonate to ethyl iodide. Many years later, methyl and ethyl i0dides8~0~~~1 and ethyl a-iodopropionate*05" were prepared in good yield by the action of the same iodide (in boiling water or alcohol) on the corresponding p-toluenesulfonates. In these examples, the reaction obviously proceeded as an alkyl-oxygen fission,**in accordance widh the following equation:
Not until 1927 was the reaction applied841to a sulfonic ester o j a sugar derivative. The idea of trying it in this connection presumably arose from (a) the earlier observations*6ea' that, toward nucleophilic reagents, sulfonic esters usually act similarly to alkyl halides and eaters of nitric acid, and (b) the then-recent discovery that Finkelstein's reagent848 (uit., a solution of anhydrous sodium iodide in anhydrous acetone, which had been used for converting alkyl bromides and chlorides to the corresponding iodides) transforms both methyl 6-bromo-6-deoxy-2,3,4-tri-~-methyl-~-glucoside~~~ and methyl 2,3,4-tri-O-methyl-~-glucoside 6-nitrate24a to methyl Bdeoxy-6-iodo2,3,4-tri-O-methyl-~-glucoside, in good yield; treatment with 2 molecular proportions
AHp:-ONO*
I
! Na
of sodium iodide in acetone, during 6 hours at 100" (in a sealed tube) was employed.
(339) J. H. Kastle, P. Murrill, and J. C. Fraeer, Am. Chern. J . , 18, 894 (1897). (340) D.H. Peacock and B. K. Menon, Quart. J . Indian Chem. Soc., 2,240 (1925). (341) W.Rodionow, Bull. 8oc. chim. France, [4],3@,305 (1926). (342)K.Freudenberg and K. Rsschig, Bw., 60, 1633 (1927). (343) H.Finkelstein, Ber., 43, 1528 (1910). (344) J. C. Irvine and J. W. H. Oldham, J . Chem. Soc., 187, 2729 (1925).
SULFONIC ESTERS OF CARBOHYDRATES
181
1. Action of S o d i u m Iodide o n Primary Sulfonyloxy Groups
For work in the sugar series, the advantage of acetone as a solvent (compared with w a t e F or ethanol, employed in the earlier studies mentioned) is that it dissolves the sodium iodide, the sulfonic ester, and the deoxyiodosugar derivative, but dissolves practically none of the sodium sulfonate formed. Use of other solvents is discussed on p. 197. a. Primary Sulfonyloxyl Group of a Mono-0-sulfonylated A1dose.-On treating 1,2:3,4-di-O-isopropylidene-6-0-tosyl-~-galactose with a 10% solution of sodium iodide in acetone during 36 hours a t 125' (sealed tube), desulfonyloxylation occurred, giving342,34b the corresponding 6-deoxy-6odo derivative:
-+
CHJ
Prior to 1932, a year of some significance in this field (see p. 191), the reaction was, for example, applied to the preparation of methyl 2,3,4tri-0-acetyl-6-deoxy-6-iodo-a-~-g~ucoside~*~ (25 hours at 130"), 2,3,4,2',(24 hours a t 130"; 3',4'- hexa-0-acetyl-6,6'-ddeoxy-6,6'-diiodo-trehalo~e~~~ 89 % yield) , and methyl 2,3,4,2',3'-penta-0-acetyl-6,6'-dideoxy-6,6'diiodo~-cellobioside"4s (60 hours at 100"; 94% yield of product; 100% yield of sodium p-toluenesulfonate) . Such products are valuable in the preparation of other w-derivatives, e.g., w-deoxy sugars (see p. 157). Some other mono-0-sulfonylated-aldose derivatives to which the iodination reaction has since been successfully applied (either preparatively or diagnostically, or both) are listed in Table 111. The yields given therein are those recorded by the authors, and have not been recalculated. Where the yield approaches the theoretical, there is seldom any indication that the same yield might not have resulted a t a lower temperature or after a shorter reaction-time, or both. Low yields might, in some instances, be attributable to poor experimental technique. However, despite its deficiencies, Table I11 contains sufficient information to warrant a few conclusions, some of which are to be found scattered through the literature. (345) (346) (347) (348)
K. Freudenberg and K. Raschig, Ber., 62, 373 (1929). B. Helferich and E. Himmen, Ber., 61, 1825 (1928). H. Bredereck, Ber., 8S, 959 (1930). B. Helferich, E. Bohn, and S. Winkler, Ber., 63, 989 (1930).
182
R. STUART TIPSON
TABLEI11 Replacement,' b y Iodine, of Primary Sulfonyloxy G o u p of Mono-0-sulfonyl-aldose Derivatives
NO.
__
1 2
3 4 5 6 7 8
9 10
11
~
~~
Temp., Time, Compound "C. hrs. ~1,2,3-Tri-O-acetyl-5-O-tosyl-~-arabinose 100 1 lJ2-O-Isopropylidene-5-O-tosyl-~ 100 6 arabinose Methyl 2,3-di-O-acetyl-5-O-tosyl-cu-~arabinoside Methyl 2,3-0-isopropylidene-5-0-tosyln-ribofuranoside 100 2 9'- (2,3-Di-O-acetyl-5-O-tosyl100 2 99c j3-D-ribofuranosyl)-N-tosyl-adenine 9'-( 2,3-O-Isopropylidene-5-0-tosyl-~-~99c 100 2 ribofuranosy1)-hypoxanthine 3'-(2,3-Di-0-methyl-5-0-tosyl-p-~100 2 ribofuranosy1)-uracil 3'-(2,3-0-Isopropylidene-5-0-tosy~-~-~100 2 ribofuranosy1)-uracil 3-O-Acetyl-l,2-0-isopropylidene-5-0100 tosyl-D-xylose 59 32d 3-0-Benzoyl-l ,2-O-isopropylidene-5-0100 38d 62 tosyl-D-x ylose
{f { 100 {f
References
134 134 134 207 111 331 107
I I I
1,2-0-Isopropylidene-5-0-tosyl-~-xylose 88 67d 11 1,2-0-Isopropy~idene-5-0-tosyl-~-xylose 100 6 98b 12 1,2-O-Isopropylidene-5-O-tosyl-~-xylose 100 2 4 ~ 13 Methyl 3,4di-O-acetyl-2-deoxy-6-080 2 tosy1-a-D-alloside 54c 14 Methyl 2-deoxy-3-0-methyl-6-O-tosyl80 CY-D-"allopyranoside '' 3 15 Methyl 4-0-acetyl-2,3-anhydro-6-080 4 tosyl-cu-D-alloside 70c 16 Methyl 2-0-methyl-6-0-tosyl-cu-~100 6 altropyranoside 17 Methyl 3,4-di-O-acetyl-2-0-methyl-6-0100 6 bsyl-cu-D-altroside 77b 18 Methyl 2,3,4tri-0-acetyl-6-O-tosyl-a-~100 4 altroside 19 Methyl 2,3,4-tri-O-benzoyl-6-0-tosyla-D-altroside 70' 18 93" 20 3,4-O-Isopropylidene-6-o-mesyl-~115-25 galactal 5.: 11 .2c.g 21 3,4-0-Isopropylidene-6-O-tosyl-n115-25 galactal 5.1 13.8evu 22 1,2:3,4-Di-O-isopropylidene-6-O-mesyl- (115-25 5.t 1130-35 40 93°C D-galactose
349 133 133 133 263 350 181 269 181 184 184 351 352 169 169 169
183
SULFONIC ESTERS O F CARBOHYDRATES
TABLEI11 (Continued)
No.
Compound
Temp.,
"C.
V'
an hri
Yield,b*c* References percent
-
22 1,2:3,4Di-O-isopropylidene-6-0-mesylD-galactose 100 96 23 1,2:3,4-Di-O-isopropylidene-6-0-tosylD-galactose 105-10 36 23 1,2:3,4-Di-O-isopropylidene-6-O-tosyl- f 115-25 5 D-galactose I 115 20 24 6-O-Tosyl-D-galactose 115-25 5 25 Methyl 2-0-acetyl-3,40-isopropylidene6-O-tosyl-a-~-galactoside 120 6 26 Methyl 2-deoxy-3,4-0-isopropylidene6-O-tosyl-a-~-"galactoside " 140 5 27 Methyl 2-0-methyl-3,40-isopropylidene-6-0-tosyl-a-~-galactoside 140 5 28 Methyl 3,4-0-isopropylidene-6-0-tosyl112 15 a-D-galactoside 29 Methyl 2,4di-O-acetyl-3-0-methyl-6-0tosyl-a-D-galactoside 124 36 30 Methyl 2,4di-O-acetyl-3-0-methyl-6-0125 6 tosyl-p-D-galactoside 31 Methyl 2-deoxy-3-0-methyl-6-O-tosyla-D-"galactopyranoside " 80 B 32 1,2,3,4-Tetra-O-acetyl-6-O-mesyla-nglucose 100 2 33 1,2,3,PTetra-O-acetyl-6-0-mesyl-@-~glucose 100 2 33 1,2,3,4Tetra-O-acety1-6-~-mesy~-@-~-I 20 36 Ireflux 3 glucose 34 1,2,3,4-Tetra-0-acetyl-6-0-tosyl-a-~refluxh 1 glucose 35 1,2,3,4Tetra-0-acetyl-6-0-tosyl-~-~refluxh glucose 1 36 Ethyl 2,3,4-trideoxy-6-0-mesyl-a-~"glucoside" 115-20 5 37 Methyl 2,3,4-tri-0-acetyl-6-O-to~yl~-~100 1 glucoside 37 Methyl 2,3,4-tri-0-acety1-6-0-tosyl-a-~refluxi glucoside 3 38 Methyl 2,3,4-tri-O-acetyl-6-0-tosyl-fi-~glucoside 100 1 39 Methyl 2,3,4-tri-O-benzoyl-6-O-tosyla-D-glucoside 40 Methyl 6-O-tosyl-fi-~-glucopyranoside 100 2 41 Methyl 2,4-di-O-acetyl-3-0-methyl-6-0tosyl-@-D-glucoside 100 20
-
99b 85b
1 ooc 1 23 .9c*o 1 9ib 1 76.8c90 67b 1 8W I 36c ca.
50b
190 72, 353 169 169 226 354 232 355
81b
309
60"
268
75 c
270
65b
190
96b
190 24
396
97
95b
97
53c
356 171 357 171 260 72, 358
72b
359
184
R, STUART TIPSON
-
TABLEI11 (Continued)
No.
Temp.,
Compound
“C.
zm Yield,b+*’ References hrs percent
1.
-
42 Methyl 2,3,4tri-O-methy1-6-O-toayl100
cu-D-ghcoside
43 3,5-Di-O-acetyl-l,2-0-isopropylidene6-O-tosyl-~-gluoose
44 3,5-O-Benzylidene-l,2-0-isopropylidene45 46 47
48 49 50 51
-
100 -74
64b SOb
4 reflux 6-O-mesyl-~-ghcose 3,5-O-Benzylidene-l,2-0-isopropylidene90 3 6-O-tOt3yl-D-ghCOSe 1,2-O-Isopropylidene-6-O-tosyl-~refluxh 2. glucofuranose 1,2:3,5-Di-O-isopropylidene-6-0-tosylD-glucose 80 3 Methyl 2,3,4,2’,3’-penta-O-acetyl-6,6’di-0-mesyl-p-oellobioside Methyl 2,3,4,2’,3’-penta-O-acetyl-6,6’di-0-tosyl-8-cellobioside 100 60 Methyl 2,3-di-O-acetyl-4-0-methyl6-O-tosyl-a-~-mannoside 100 2 Methyl 2,3,4-tri-0-bensoyl-6-O-tosyla-D-mannoside 100 2
*
360
5
-
LOO“
1 I
113,359 321 146 (34,361)
86b
362 246 946 LOOC
1 I
284 172,348
LOOb*C
251
l0OC
173
a Unless otherwise noted, acetone was the solvent. Yield of deoxyiodo-sugar derivative. 0 Yield of sodium sulfonete. d Yield by determination of sodium iodide consumed. Free iodine liberated. I Acetonylacetone. 0 Corrected for solubility of sodium sulfonate in acetone. Acetic anhydride. Isobutyl methyl ketone.
(349) P. A. Levene and R. 8. Tipson, J . Biol. Chem., 106, 113 (1934). (350) H. Miiller and T. Reichstein, Helv. Chim. Acta, 21, 251 (1938). (351) M. Gut and D. A. Prim, Helv. Chim. Acta, 29, 1555 (1946). (352) D.A. Rosenfeld, N. K. Richtmyer, and C. S. Hudson, J . Am. Chem. SOC., 70, 2201 (1948). (353) A. L.Raymond and E. F. Schroeder (to G. D. Searle & Co.), U. S. Pat. 2,365,777(Deo. 26,1944); Chem. Abstracts, 39, 4434. (354) A. B.Foster, W. G. Overend, and M. Stacey, J . Chem. Soc., 974 (1951). (355) 0. T.Schmidt and E. Wernicke, Ann., 668, 70 (1947). (356) S.Laland, W. G. Overend, and M. Stacey, J . Chem. Soc., 738 (1950). (357) M.Zief and R. C . Hockett, J . Am. Chem. SOC.,67, 1267 (1945). (358) A. L. Raymond and E. F. Schroeder (to G. D. Searle & Co.), U. S. Pat. 2,365,776(Dec. 26,1944); Chem. Abstracts, 89, 4434. (359) B. Helferich and 0. Lang, J . prakt. Chem., 132,321 (1932). (360) C. C.Barker, E. L. Hirst, and J, K. N. Jones, J . Chem. Soc., 1695 (1938). (361) P. A. Levene and A. L. Raymond, Ber., 66, 384 (1933). (362) G. R. Barker and R. W. Goodrich, J . Chem. SOC.,S 233 (1949).
SULFONIC ESTPRS O F CARBOHYDRATES
185
For D-galactose, a 64osyloxy group (compounds 21, 23) i s somewhat more reactive than the (smaller) 6-mesyloxy group (compounds 20, 22), and the same is probably true of D-glucose derivatives (compounds 34 and 32; 35 and 33). Secondly, a conjigurational eflect (e.g., as between one sugar and an isomer) is noticeable. Allose, altrose, mannose, and ribose derivatives react almost quantitatively under relatively mild conditions, and so do many glucose derivatives. However, there seems to be no doubt that D-galactose derivatives (compounds 20 to 31), and, probably, xylose derivatives (compounds 9 to 12) require much more drastic conditions for accomplishing desulfonyloxylation than do derivatives of D-glucose (compounds 32 to 49) and, possibly, of L-arabinose (compounds 1 to 3). For example, a 6-O-mesyl-~-glucose (compound 33) is much more reactive than a 6-O-mesyl-~-galactose (compound 22) ; the same appears to be true of the corresponding 6-O-tosyl derivatives (cf., compounds 47 and 23). This observation suggests a steric effect arising from spatial proximity of the 6-sulfonyloxy group t o differing groups in t8he respective sugar molecules. A somewhat related influence appears to be exhibited by anomers. Thus, derivatives of P-D-galactose (e.g., compound 30) are more reactive than derivatives of a-D-galactose (compound 29) ; similarly 8-D-glucose derivatives (e.g., compounds 33 and 35) are more reactive than a-D-glucose derivatives (compounds 32 and 34). Presence of a methylene group in the sugar chain (e.g., the 2-deoxy group of compound 31) greatly increases the reactivity; this effect will be discussed subsequently (see p. 195). An acetal ring reduces the reactivity of the 6-sulfonyloxy group, and two acetal rings may reduce it even more; compare, compounds 20 and 21; 26; 23 and 24; 32 and 43. The effect of an acetal ring (on reactivity) is greater with a mesyloxy group than with a tosyloxy group (cf., compounds 20 and 21). Finally, the nature of the group on the carbon atom contiguous to that bearing the sulfonyloxy group has an effect on the behavior of the latter group. An influence is noticeable with the following groupings attached at the penultimate carbon atom : hydroxyl, carboxylic ester, acetal ring, (anhydro ring, see p. 189), and sugar ring. In 6 of the 7 cases in which liberation of free iodine has been definitely reported (compounds 12, 23, 25, 29, 30, 31, 43) the primary sulfonyloxy group is contiguous to the carbon atom engaged in ring formation; presumably the hydrogen of this LObH bHeI --t
AH,
carbon atom is detached, with formation of a deoxy-glycoseen by desul-
186
R. STUART TIPSON
fonyloxylation-dehydrogenation. (In compound 43, the secondary hydroxyl group contiguous t o the sulfonyloxy group is acetylated, and the nature of the by-product, possibly an anhydro-sugar, was not estab-
'J
HCO I
H0-J I
lished.) In none of the examples cited did this side-reaction (involving iodine liberation) occur to a pronounced extent, although Raymond and Schr~eder'~ point out that, under their conditions, compound 23 gave an 85% yield of desired 6-deoxy-6-iodo derivative (with liberation of only a trace of iodine) , whereas, by use of Freudenberg and Raschig's original conditions, 5 4 2 a considerable amount of decomposition occurred. However, one compound is known with which formation of the 5-deoxyglycoseen-5,6 proceeds34to completion (in acetone) in 2 hours a t 100'; this compound is 1,2-0-isopropylidene-6-O-tosyl-~-glucofuranose.However, if the reaction is conducted in boiling acetic anhydride under reflux (Table 111, compound 46), acetylation362 takes place, and 3,5-di-O-acetyl6-deoxy-6-iodo-1,2-O-isopropylidene-~-glucose may be isolated (as from compound 43). As regards compound 5 (Table 111),it may be noted that the O-tosyloxy group reacts, but the N-tosyl group does not. A so-called 2,3-0isopropylidene-5-0-tosyl-adenosineis saida6ato undergo the iodination reaction with simultaneous cyclization, to yield 2,3-0-isopropylidene-5,3'cyclo-adenosine iodide. b. Primary Sulfonyloxy Group(s) of a-, W-, or a,w-0-Sulfonylaled A1ditols.-Much the same behavior characterizes the primary sulfonyloxy groups of sulfonylated sugar alcohols. Some compounds to which the reaction has been applied (either preparatively, or diagnostically, or both) are listed in Table IV. Here again, iodine is liberated with a compound having a primary sulfonyloxy group next to a secondary carbon atom whose oxygen atom is engaged in ring formalion (as in the isopropylidene acetal, compound 13) or is present as a free hydroxyl group (cf., compounds 20 and 21). In the latter category is 1,4-anhydro-6-0-tosylsorbitol which, on treatment12 with the hot reagent, "decomposes with liberation of iodine." Furthermore, when 3,6-anhydro-l-deoxy-l-iodo4,5-O-isopropylidene-~-mannitol is with this reagent during 12 hours a t 210-1501 3,6-anhydro-4,5-0-isopropylidene-~-mannitoleen-l,2 (363) V. M. Clark, A. R. Todd, and J. Zussmm, J . Chem. SOL, 2952 (1951).
SULFONIC ESTERS OF CARBOHYDRATES
187
TABLEI V Replacement,a b y Iodine, oj Primary Sulfonyloxy Group(s) of a-, W - , or a,@-0-Sulfonylated Alditols
--
No.
Compound
1 [Di-0-tosyl ethylene glycol]
Temp.
"C. 25
I
28
I24e
16d' 7sdJ 364 48d 179 1OOd 365
2 2-O-Benzoyl-3-deoxy-l-0-tosyl-~, Lreflux 2.5 glyceritol 2 95-10 3 2,3-O-Isopropylidene-1,4-di-O-tosylD-threitol 100 2.7 4 1,3:2,4-Di-O-methylene-5-O-tosyl-~,~-ribitol801 4 1OOb 5 1,3-Anhydro-2,4-0-methylene-5-0-tosyl88b1 D,GXylitOl 100' 46 9 PJ 6 3,5-O-Benzylidene-2,4O-methylene-l-Otosyl-D,L-xylitol 1201 48-72 96b 7 2,4:3,5-Di-O-methylene-l-0-tosyl-~, L-xylitol 100 4 50d] 1201 4 1OOd reflux' 1 iwdj 8 2,3,4.5-Di-O-isopropylidene-l-0-tosyl100 2 94d1 D,Gxylitol reflux 2 i8dJ 8 2,3,4,5-Di-O-isopropylidene-l-0-tosyln,Lxylitol 601 19 88b 9 2,4:3,5-Di-O-methylene-l,6-di-O-tosyl-allitol 100 7.5 85d 10 2,3,4,5-Di-O-benrylidene-l, 6-di-0-tosyldulcitol (I and 11) refluxh 1 100" 11 2,3,4,5-Di-O-isopropylidene-1,6-di-0-tosyl- 100 2 81d dulcitol refluxh 1 1OOd 12 I,5-Anhydro-2,3,4tri-0-benzoyl-6-O-tosylD-galactitol 100 2 21-23d 13 2,3,4,5-Di-O-isopropylidene-l-O-tosylL-fucitol 100 1" 2;. lOOd :2,4-di-O-ethylidene-614 5-0-Acetyl-l,3 0-tosyl-sorbitol 00-10 5 80d 15 2,3,4,5-Tetra-O-benzoyl-l,6-di-O-tosylsorbitol 100 2.5 16 l,PAnhydro-2,3,5-tri-0-benzoyl-6-0-tosylsorbitol 100 1 85b (or 2),5-0-benzylidene17 1,4-Anhydro-3 6-0-tosyl-sorbitol 100 2 80b 18 1,4,5-Tri-O-acetyl-3,6-anhydro-l-0-tosylsorbitol 110 80d PO-methylene-1,619 1,5-Di-O-acetyl-2, 100 2 di-0-tosyl-sorbito1 801 5 20 i-Deoxy-6-iodo-2,4-O-methylene-l-O-tosylsorbitol 100 3 1;" 50d 5' :a,&di-O-methylene21 j-Deoxy-6-iodo-2,4 1-0-tosyl-sorbitol .efluxh 2 92c
-
-
Time, Yield,b-c*c Rejerhrs. Percent encea
366 266 180
180 367 368 369 370 371 273 87 314 372 373 374 72 72 139 170 170 170 -
188
R. STUART TIPSON
-
TABLE IV (Continued)
No.
--
Compound
Pemp., rime, Yield,b+Id Zeferhrs. Percent mces "C.
-
22 2,4-0-Methylene-l,6-di-O-tosyl-sorbitol 22 2,4O-Methylene-l,6-di-O-tosyl-sorbito1 23 2,4:3,5-Di-O-methylenel,&di-O-tosylsorbitol 24 2,5-Anhydro-l,6-di-0-tosyl-~-iditol 25 2,4:3,5-Di-O-methylene-l,6-di-O-tosyl-~iditol 26 2,4,5-Tri-O-acetyl-1,3-0-ethylidene-6-0tosyl-D-mannitol 27 1,3,4-Tri-0-acetyl-2,5-0-methylene-6-0tosyl-D-mannitol :3,4-di-O-isopropylidene-628 5-0-Acetyl-1,2 0-tosyl-D-mannitol 29 1,5-Anhydro-2,3,4-tri-O-benaoyl-6-0tosyl-D-mannitol 30 3,6-Anhydro-2,4,5-tri-O-acetyl-l-O-tosylD-mannitol 31 3,6-Anhydro-2-O-acetyl-4,5-O-isopropylidene-l-O-tosyl-D-mannitol 32 3,6-Anhydr0-4,5-O-isopropylidene-l-Otosyl-D-mannitol 33 2,3,4,5-Tetra-O-bensoyl-1,6-di-O-tosylD-mannitol 34 2,3,4,5-Di-O-benaylidene-l,6-di-O-tosylD-mannitol 35 2,3,4,5-Di-0-methylene1,6-di-O-tosylD-mannitol 6-di-0-tosyl36 2,4:3,5-Di-0-methylene-I, D-talitol 37 2,5-Anhydr0-3,4-deoxy-1,6-di-O-tosyler ythro-hexitol
-
100 100 110 *efluxh 100 100 100 110' Sefluxh
5 2 80d 8 91" 2 2 100b 70c 5 2 95;"97d 24 1.5
100
3
100
2
05-10
2.5
96d
170 375 376 170 204 377 378
100"d
251
90d
373
100
3
100
12
78d
380
15-20
4
88d
381
80-90
4
91d
382
379
76
100
2.5
100
2
9gC
235
100
2
99
383
reflux*
1
low
384
05-10
5
1OOd
385
-
0 Unless otherwise noted, acetone was the solvent. b Yield of monodeoxy-monoiodo-alditol derivative. 0 Yield of dideoxy-diiodo-alditol derivative. d Yield of sodium sulfonate. Free iodine liberated. Aaetonylacetone. 0 Plus sodium bicarbonate to prevent cleavage of the benaylidene group. h Acetic anhydride.
(364) R.S.Tipson,Mary A. Clapp, and L.H. Cretcher, J. Org. Chem.,12, 133 (1947). (365) W. C . J. Ross, J.Chem.Soc.,2257.(1950). (366) L. J. Rubin,H.A.Lardy,and H.0.L.Fischer, J.Am. Chem.Soc., 74, 425 (1952). (367) R. M. Hann, A. T.Ness, and C.S. Hudson,J. Am. Chem. Soc., 66, 670 (1944).
SULFONIC ESTERS O F CARBOHYDRATES
189
is formed. After the discovery that a l-0-tosyloxy group of a tosylated ketose is resistant to the reagent (see p. 190), the same kind of behavior was found with the 1-0-tosyloxy group of tosylated hexitols (e.g., compounds 22 and 23) ; it is therefore possible to prepare both a 6-deoxy-6iodo-l-O-tosyl- and a 1,6-dideoxy-l,6-diiodo-hexitolderivative from a 1,6-di-0-tosyl-hexitol. With acetone as solvent, the yield of the dideoxydiiodo derivative is improved170if all free hydroxyl groups are first acetylated; hence acetic anhydride is preferable to acetone as the reaction medium in such iodinations. These a- and w-deoxyiodo and a,w-dideoxydiiodo derivatives are useful for the preparation of other a- and w-derivatives, including a- and w-deoxy- and a,w-dideoxy-alditols (see p. 157). Probably most significant is the observation that presence of an anhydro ring may, like presence of an acetal ring, confer stability on a primary sulfonyloxy group (cf., compounds 5 and 8; 12 and 13; 27 and 30, for example). c. Primary Sulfonyloxy Group of a Mono-O-sulfonylated Aldonic Acid. Very little information is as yet available regarding the behavior of compounds of this class towards Finkelstein's reagent. TreatmentaBo of methyl 2,4 :3,5-di-O-bensylidene6-O-tosyl-~-idonate with the reagent (368) R. S. Tipson and L. H. Cretoher, J. Org. Chem., 8, 95 (1943). (369) R. M. Hann, A. T. Ness, and C. S. Hudson, J. Am. Chem. Soc., 66, 73 (1944). (370) M.L. Wolfrom, B. W. Lew, and R. M. Goepp, Jr., J. An. Chem. Soc., 68, 1443 (1946). (371) W. T.Haskins, R. M. Ham, and C.S. Hudson, J. Am. Chem. Soc., 64, 137 (1942). (372) A. T. Ness, R. M. Ham, and C. S. Hudson, J. Am. Chem. Soc., 64, 982 (1942). (373) L. F. Wiggins, J. Chem. Soc., 388 (1946). (374) Y. Hamamura, J . Agr. Chem. Soc. Japan, 18, 581 (1942); Chem. Abstracts, 46, 4652. (375) E.J. Bourne and L. F. Wiggins, J . Chem. Soc., 517 (1944). (376) R. M. Hain, J. K. Wolfe, and C. 8. Hudson, J. Am. Chem. Soc., 66, 1898 (1944). (377) R. M. Hann and C. S. Hudson, J. Am. Chem. Soc., 67, 602 (1945). (378) E.J. Bourne, a. T. Bruce, and L. F. Wiggins, J . Chm. SOC.,2708 (1951). (379) L. Zervas and Irene Papadimitriou, Ber., 73, 174 (1940). (380) L. F. Wiggins, J. Chem. Soc., 4 (1945). (381) A. B. Foster and W. G. Overend, J. Chem. Soc., 1132 (1951). (382) A. B. Foster and W. G. Overend, J. Chem. Soc., 3452 (1951). (383) W.T.Haskins, R. M. Ham, and C. S. Hudson, J. Am. Chem. Soc., 6.5, 67 (1943). (384) R. M.Hann, W. T.Haskim, and C.S. Hudson, J. Am. Chem. Soc., 69,624 (1947). (385)L. F. Wiggins and D. J. C. Wood, J. Chem. Soc., 1566 (1950). (386) E. Seebeck, E.Sorkin, and T. Reichstein, Helu. Chim. Ada, 28, 934 (1945).
190
R. STUART TIPSON
(during 5 hours a t 100") gave a sulfur-free product, said to be methyl
2,4:3,5-di-O-benzylidene-~-idonate (on the dubious basis aff orded by a mixed melting-point determination). On the other hand, the corresponding 6-0-mesyl derivative remained completely unchanged on treatment as above (or even during 5 hours at 120"); this is a further example of the lower reactivity of a 6-0-mesyl group as compared with a 6-O-tosyl group. In contrast to these results, methyl 2,4:3,5-di-Omethy~ene-6-0-tosyl-~-gluconate givesas7methyl 6-deoxy-6-iodo-2,4 :3,5di-0-methylene-D-gluconate,in practically quantitative yield, on treatment with the reagent during 2.5 hours a t looo. d. Primary Sulfonyloxy Group of a-,W - , or a,w-O-Sulfonylated Ketoses. Because'the reactivity of the primary hydroxyl group at carbon atom 1 is profoundly affected by the presence of the adjacent ketonic function at carbon atom 2 of k e t w s , Levene and Tipson"8 became curious as t o the behavior of a lone 1-0-tosyl group (towards Finkelstein's reagent). They therefore tested 2,3 :4,5-di-O-isopropy~dene-l-O-tosy~-~-fructose, CH~OTS I
and discovered388that it is completely unagected at lOO", during either 2 or 8 hours; the solution remained colorless, and no sodium p-toluenesulfonate was formed. The experiment was repeated and, even after 5 days at 130-135", only a trace of sodium p-toluenesulfonate was isolated; a trace of free iodine was liberated, but a large proportion of the starting material was recovered unchanged. Similarly, the reagent is without effect208 on phenyl 3,4,5-tri-O-acetyl-l-O-mesyl-~-~-fructoside (during 40 hours a t 125-130'). However, on treating2666-deoxy-2,3-0isopropylidene-1-0-tosy1-D-fructose during 48 hours at 125", sodium p-toluenesulfonate and some free iodine are formed, and some of the 1-deoxy-1-iodo derivative (yield, not stated) may be isolated. 6-Deoxy2,3-0-isopropylidene-l-O-tosyl-~-sorbose b e h a v e P similarly (36 hours at 125'). Under even more conditions, uiz., 100 hours at 100" under nitrogen pressure of 1,000 lbs. per sq. in., the exchange reaction (387) C.L. Mehltretter, R. L. Mellies, C. E. Rist, and G. E. Hilbert, J . Ant. Chern. 69,2130 (1947). (388) P.DA. Levene and R. S. Tipson, J . Biol. Chm., 120, 607 (1937).
Soc.,
SULFONIC ESTERS O F CARBOHYDRATES
191
proceeded to the extent of some 50% with 2,3 :4,6-di-O-isopropylidene1-0-tosyl-L-sorbose ; re-treatment under the same conditions afforded some of the 1-deoxy-1-iodo derivative (yield, not stated). I n contrast, the 6-tosyloxy group of 1,6-di-O-tosylketohexofuranose derivatives is more readily re'placed by iodine. Thus, by reaction during 24 hours a t 90-lOO", 2,3-0-isopropylidene-1,6-di-0-tosyl-~-sorbose gives284 the corresponding 6-deoxy-6-iodo-1-0-tosylderivative (possibly accompanied by some unisolated 1,6-dideoxy-l,6-diiodo derivative) ; and 2,3-0isopropylidene-1,6-di-0-tosyl-~-fructose behaves2s6 similarly (16 hours at 100"). 2. Action of S o d i u m Iodide o n Secondary Sulfonyloxy Groups
I n all the examples so far considered, the reaction of sodium iodide with one or more primary sulfonyloxy groups, only, was involved. However, in 1932, Oldham and RutherfordZ0published the first study of the behavior (towards this reagent) of some D-glucose derivatives containing secondary sulfonyloxy groups, thereby opening up a field of research whose possibilities have still not been fully explored. a. Secondary Sulfonyloxy Groups Non-contiguous to, or N o t Accompanied by, a Primary Sulfonyloxy Group, in Cyclic-Sugar Derivatives.-On treating methyl 2,3-di-O-methyl-4,6-di-O-phenylsulfonyl-~-~-glucoside with an equal weight of sodium iodide in acetone (volume, not stated) during 2 hours a t lOO", these authors20 found that, in conformity with the experience of the earlier workers (see p. 181), the 6-phenylsulfonyloxy group reacts readily and quantitatively, but they also found that the secondary sulfonyloxy group does not react appreciably under these conditions, and the product was recognized to be methyl 6-deoxy-6-iodo-2,3di-0-methyl-4-0-phenylsulfonyl-/3-~-glucoside. They stated20 that "it
is important to limit the time of heating t o two hours, since prolonged treatment seems t o lead also to the replacement of the 4-group and t o other complications." By using these very clearly stipulated conditions, they found that non-contiguous primary and secondary tosyloxy groups
192
R. STUART TIPSON
of tosylated D-glucose derivatives similarly display differential reactivity, and that, in the absence of a primary tosyloxy group, secondary tosyloxy groups are practically unreactive. Thus, methyl 2,3-di-O-acetyl-4,6-diO-tosyl-P-~-glucosidegavez0a 92 % yield of the corresponding 6-deoxy-6iodo-4-0-tosyl derivative, and methyl tetra-0-tosyl-P-D-glucopyranoside gave a 93% ’ yield of the 6-deoxy-6-iodo-2,3,4-tri-O-tosylderivative. Furthermore, under their conditions, the following compounds (having no primary sulfonyloxy group) did not react20 with sodium iodide in acetone: 2,3,4-tri-O-phenylsulfonyl-glucosan, methyl 2,3,6-tri-O-methyl-5-O-tosylD-glucoside, methyl 4,6-di-O-rnethyl-2,3-di-O-tosyla-~-glucoside, and 1,2:5,6-di-0-isopropylidene-3-0-tosyl-~-glucose. Hence, they clearly demonstrated20that, in such compounds of D-glucose, under the prescribed conditions of treatment, (a) a phenylsulfonyloxy or tosyloxy group at position 6 reacts almost quantitatively ; (b) these substituents a t positions 2,3,4, or 5 are unreactive; and (c) these properties are independent of the ring structure (furanose or pyranose) of the D-glucose derivative. These principles have often been referred to as “Oldham and Rutherford’s Rule.” Oldham and RutherfordZ0therefore proposed use of the following method for ascertaining the presence of a free primary hydroxyl group in substituted D-glucopyranose derivatives: (1) tosylate the compound ; ( 2 ) permit the tosylation product to react with sodium iodide (used in excess) in acetone during 2 hours a t 100”; and (3) treat the iodinat,ion product with silver nitrate in acetonitrile (see p. 155), and weigh t,he resulting silver iodide. (They did not imply that this method would be applicable either to D-glucofuranose derivatives having a secondary sulfonyloxy group contiguous to the primary sulfonyloxy group, or to O-sulfonyl derivatives of other sugars, sugar alcohols, etc.) It may be noted that Oldham and Rutherford20 recommended use of a standard temperature and reaction time, but only once mentioned the proportion of sodium iodide they employed (“an equal weight,” as already noted); in no case did they indicate how much acetone they employed. However, experience has shown that neither too great nor too small an excess of sodium iodide should be used, and that the acetone solution should not be too dilute. A series of comparative experiments has been performed389 under the followinga64standard conditions: a weighed amount of the sulfonic ester is treated with one hundred per cent excess (2 molecular equivalents per sulfonyloxy group) of a 10%solution of anhydrous sodium iodide in anhydrous acetone, in a sealed tube at 100” during 2 hours. Nowadays, the third step of Oldham and Rutherford’s diagnostic procedure is usually omitted, since a highly satisfactory indicationSB4 of the (389) R. S. Tipson and P. Block, Jr., J . Am. Chem. SOC.,66, 1880 (1944).
SULFONIC ESTERS OF CARBOHYDRATES
193
extent of reaction is afforded by weighing the sodium p-toluenesulfonate which crystallizes out in the second step, because the solubility of the sodium sulfonates in the reaction solution is slight. However, a correction (not physico-chemically proper) has been introduced169by assuming that the solubility in the reaction solution is the same as in pure acetone, viz., for sodium methanesulfonate, 0.04 g.; and for sodium p-toluenesulfonate, 0.12 g. per 100 cc. of acetone a t 18". No case has been reported in which the solubility of the sodium sulfonate is appreciably modified, or its crystallization inhibited, by a sulfonic ester or its iodination product. However, a method which is unaffected by these possibilities and is adaptable t o use on a micro scale, consists133in determination of the sodium iodide consumed during the reaction, by titration of aliquots of the reaction solution, for in-organic iodide, with staadardized silver nitrate-ammonium thiocyanate (and ferric alum as indicator). Should free iodine be liberated, the sealed tube should be cooled in Dry Icechloroform immediately after elapse of the heating period, opened, and the iodine estimated3" by titration with standardized sodium thiosulfate solution (with starch as indicator); if the iodination reaction is prolonged, the results may be deceptive, because of some iodination of the acetone. I n the iodination of some tosyl esters of primary monohydric alcohols, three molecular equivalents of dry sodium iodide in pure acetonylacetone were employed, and the reaction was followed182by observing the change in refractive index of the reaction mixture; as for the action of sodium ethoxide on ethyl sulfonates, 390 the iodination reaction followed secondorder kinetics. Confirmation of Oldham and Rutherford's Rule, as applied t o D-glucose derivatives, was not long in forthcoming; and little time elapsed before attempts were made to find out whether the Rule could be extended to other sugars. Table V lists the behavior of some cyclic-sugar derivatives bearing one or more secondary 0-sulfonyl groups non-conliguous to the primary 0-sulfonyl group. I n 1933, confirmation of the fact that, under drastic conditions, a secondary as well as a primary tosyloxy group can react, was afforded24O by the isolation of some methyl 4-0-acetyldideoxy-diiodo-mono-0-tosyl-P-D-" glucoside" on treating compound 19 (Table V) with 4.6 molecular equivalents of sodium iodide in acetone during 25 hours at 130"; similar behavior, to a lesser extent, was observed in 1937 with compound 11, treated a t 90" and then 115". I n these, and all other, instances of replacement of a secondary sulfonyloxy group, Walden inversion may have occurred, but this point is, as yet, not settled for the iodination reaction. A 6-0-mesyl group (as in compound 23) may be so reactive that, by correct choice of conditions, only the (390) M. S.Morgan and L. H.Cretcher, J. A m . Chern. Soc., 70, 375 (1948).
194
R. STUART TIPSON
TABLEV Replacementla by Iodine, of Non-contiguous Primary and Secondary Suljonyloxy Groups in Derivatives of Cyclic Sugars
-
-
No.
Compound
1
2 3 4 5 (i
7
7 8 9 10
11
feferences
Temp., Time, hrs. “C.
if-(2-Deoxy-3,5-di-O-tosyl-p-~-“ribosyl”)-5’00 methyluracil Methyl 2-deoxy-3,5-di-O-tor~yl-a,B-~.05-10 “riboside” Methyl 3-0-methyl-2,4,6-tri-0-tosyl-a-~10 altroside Methyl 2,3-di-O-acety1-4,6-di-O-tosyl-j3-~40 galactoside Methyl 2-deoxy-3-0-methyl-4,6-di-O-tosyl10-90 a-n-“galactoside ” Methyl 3,4-0-isopropylidene-2,6-di-O-mesylL 15-25 a-D-galactoside Methyl 3,4-O-isopropylidene-2,6-di-O-tosyl115-25 a-D-galactoside Methyl 3,4-0-isopropylidene-2,6-di-O-tosyl120 a-D-galactoside 115-25 Methyl 2,6-di-O-mesyl-a-~galactopyranoside 115 Methyl 2,G-di-0-tosyl-a-~-galactopyranosideL 15-25 Methyl 3-0-methyl-2,4,6-tri-O-tosyl-P-~I20 galactoside $0then 1,4Di-O-acetyl-2,3,6-tri-O-tosyl-P-~-glucose
115
2,
1OO;d 430
110
3
LOOd
274
16
>Od
267
16f
30d
154
8f
35d
270
5.5 3.9d
169
5.5 17.gd
169
G 5.5 30 5.5
3 6 ; b 91d 37.5d 36.4d 31.2d
9, 77d 15the1 lOld 2f 55b
refluxu 0.083 12 1,3,4Tri-0-acetyl-2,6-di-O-tosyl-~-~-glucose 4Tri-0-acety l-2,6-di-O-tosyl-~-n-glucose refluxu 0.083 13 1,3, 14 Benzyl 2,3-di-O-acetyl-4,6-di-O-tosyl-j3-~2 99b 100 glucoside 15 Ethyl 2,3-dideoxy-4,6-di-0-mesyl-a-~105-10 3 “glucoside 16 Ethyl 2,3-dideoxy-4,6-di-O-tosyl-u-~-
110 “glucoside ” 17 Ethyl 2,3-didehydroxy-4,6-di-O-mesyl-a-~1105-10 “glucoside ” 18 Ethyl 2,3-didehydroxy-4,6-di-O-tosyl-a-~110-15 “glucoside” 18 3thyl 2,3-didehydroxy-4,6-di-O-tosyl-a-~- 18 “ glucoside ” 25 30
169 169 268 124 237 237 391 356
6
lOOd
356
3
93d*
356
3
934. 75’ 83. 100’ 130d
356
216, 216 216 25
19 Methyl 40-acetyl-2,3,6-tri-O-tosyl-p-~-
130
glucoside 20 Methyl 3,4di-~-acetyl-2,6-di-O-tosyl-,3-~glucoside
reflux0 0.083 lOOd
-
226
356 240 (109) 142
SULFONIC ESTERS OF CARBOHYDRATES
TABLEV (Continued) NO.
<.
-
Compound
-
Temp., Time, Yiel@*e*d*a Referhrs. Percent ences "C.
21 Methyl 2,3-di-O-benaoyl-4,6-di-O-tosyl-cu-~glucoside 100 22 Methyl 4chloro-4-deoxy-2,3,6-tri-O-tosyl-~D-"ghcoside " 105 23 Methyl 2,3,4,6-tetra-O-mesyl-cy-~-glucoside reflux 24 Methyl 2-0-methyl-3,4,6-tri-O-tosyl-B-~glucoside 100 25 Methyl 2-deoxy-3-0-methyl-4,6-di-O-tosyla-D-xylo-hexoside 97 26 Methyl 2-deoxy-3-0-methyl-4,6-di-O-tosyl-~98 D-xylo-hexoside 27 4O-Acetyl-l,6-anhydro-2,3,7-tri-O-tosyl-~glycero-8-D-gulo-heptose 70h
-
195
-l
2
low
24 4
56b 1OOd
2
' 8
117
24
175 18d
12 18
260
271 271
lOOd
156
a Unless otherwise noted, acetone was the solvent. 6 Yield of monodeoxy-monoiodo derivative. Yield of dideoxy-diiodo derivative. d Yield of sodium sulfonate (for removal of primary sulfonyloxy group). a Yield of sodium sulfonate (for removal of one secondary sulfonyloxy group). I Free iodine liberated. I .4cetic anhydride. * Acetonylacetone.
0
6-deoxy-6-iodo derivative results; thus, the latter was formed24 by reffuxing a solution of compound 23 either (a) plus sodium iodide in acetone for 4 hours or (b) plus potassium iodide in water for 3 hours. Recent experiments3b6have demonstrated that presence of a double bond between carbon atoms 2 and 3 (as in 2,3-didehydroxy-~-"glucose," i.e., 2,3-didehydroxy-erythro-hexose,see compounds 17 and 18) gives a reversal in reactivity, so that the secondary mesyloxy group is more reactive than the primary. Thus, treatment of compound 17 with sodium iodide in acetone, during 5 days a t 18", y i e l d P the 4-deoxy-4iodo-6-0-mesyl derivative; but treatment during 3 hours a t 105-10" gives the 4,6-dideoxy-4,6-diiodo derivative (a very unstable product which loses iodine after 1 day in the dark). Compound 18 behaves similarly; after treatment during 9 days at 18" in the dark, the 4deoxy4-iodo-6-0-tosyl derivative results. If the double bond is now saturated, giving compounds 15 and 16, the 6-deoxy-6-iodo-4-0-tosyl derivative is obtainable366from compound 16, and the 4,6-dideoxy-4,6-diiodo derivative from compound 15. This increase of reactivity of a secondary sulfonyloxy group by a vicinal d-deoxy (i.e., methylene) group had been discovered by Levene and Tipsonllo in 1935 (see compound 1, Table V); the secondary group reacted to the extent of some 43 % under Oldham and Rutherford's conditions. (391) A. L. Raymond, R. S. Tipson, and P. A. Levene, J. Bid. Chenz., 130, 47 (1939).
196
R. STUART TIPSON
As regards other sugars, it may be seen from Table V that, by suitable choice of conditions, the primary sulfonyloxy group is usually replaceable by iodine without agecting secondary sulfonyloxy groups noncontiguous to it. In compounds of D-galactose (compounds 6 and 7; 8 and 9) the enormous effect of a 3,4-0-isopropylidene groupinglBgon the reactivity of a 6-sulfonyloxy group is again noticed. Liberation of free iodine was reported for compounds 4,5,10,11,18, and 25, all of which conform t o the requirement previously mentioned (p. 185). Of interest in this connection is 1,6-anhydro-2,3,7-tri-0-tosyl-~-glycero-~-~-gu~o-heptop~anose which, on treatment166with sodium iodide in acetonylacetone, affords 1,6:4,7-dianhydro-2,3-di-O-tosyl-~-glycero-~-~-gulo-heptopyranose (having three oxygen rings), presumably by elimination of the elements of hydrogen iodide from the (non-isolable) 7-deoxy-7-iodo derivative. No such behavior was observedl66 with the 4-acetate (compound 27). Compound 25 exhibits unusual behavior in that, on treatment with sodium iodide in acetone it is anomerized to the 6-form (compound 26), which is271 actually isolable ; both anomers then give their 6-deoxy-6-iodo derivatives. The proportions of the three products depend2" on the temperature and the reaction-time. observed that differential reactivity In 1937, Levene and TipsonSBB also obtains with cyclic ketoses; thus, when 2,3-0-isopropylidene-1,4-diO-tosyl-D-threo-pentulose ("-D-xylulose ") is treated with sodium iodide in acetone during 2 hours a t lOO", the solution remains colorless, and no sodium p-toluenesulfonate is formed. (After treatment during 8 hours a t lOO", some of the latter was formed and some deoxyiodo derivative ' of the starting material was recovered unchanged. resulted, but over 50% It is still unknown whether iodination had proceeded at position 1 or 4, or both.) Use of this information has assistedS92in solving the structure of 2,7-anhydro-~-~-altro-heptulopyranose (sedoheptulosan) which, although it possesses a primary hydroxyl group at carbon atom 1, yieldsSg2 a 1,3,4,5-tetra-O-tosyl derivative which is unaffected by sodium iodide in acetone during 65 hours a t 100". Of incidental interest is the observation that an w-chlorine atom may be replaced by iodine under Oldham and Rutherford's conditions, without affecting secondary sulfonyloxy groups. Thus, Levene and Tipsonlo' found that 5-chloro-5-deoxy-2,3-di-O-tosyl-uridine affords the corresponding 5-deoxy-5-iodo derivative plus sodium chloride; on the other hand, methyl 4-chloro-4-deoxy-2,3,6-tri-0-tosyl-cr-~-''glucoside"gives1" the 4-chloro-4,6-dideoxy-6-iodo derivative. These observations, taken (392) J. W. Pratt, N. K. Riohtmyer, and C. S. Hudson, J . Am. Chem. Soc., 75, 1876 (1951); 74, 2200 (1952); W. T. Haskina, R. M. Hann, and C. S. Hudson, ibid., 74, 2198 (1952).
SULFONIC ESTERS O F CARBOHYDRATES
197
together, arouse suspicion regarding the supposed 6-chloro-6-deoxy1,2-0-~sopropyl~dene-3-O-methyl-5-O-tosyl-~-glucose which, it is allegedlad is unaffected by a hot solution of sodium iodide in acetone. Use of the differential reactivities of non-contiguous primary and secondary sulfonyloxy groups of cyclic-sugar derivatives has been made in elucidating the structures of larch-wood arabogalactan,aQaguar mannoand Iirna-bean galactan, 394 the hemicelluloses of corn (maize) p 0 d s 3 ~(in ~ whose tosyl derivatives some secondary tosyloxy groups reactag4with sodium iodide in acetonylacetone during 12 hours at 100acetone-soluble cellulose acetatelO~~'29~148.*~~ lo"), cellulose,10s~137~3g4~s0s (for which the 6-mesyloxy group gave less iodine uptake106 than the 6-tosyloxy group, and secondary tosyloxy groups were398 slowly replac,ed by iodine), partially ethylated,147~a97 propylated,s97 or hydroxyethylated80*81 cellulose, and starch .7,109,240,394 I n addition to varying the conditions (prescribed by Oldham and Rutherford) by trying the effects of other temperatures and reactiontimes, solvents other than acetone have been successfully employed. Thus, for compounds whose w-sulfonyloxy group is not particularly reactive, use of a ketone with a boiling point higher than that of acetone may permit conducting the reaction at an adequately high temperature under rejlux instead of in a sealed tube; e.g., acetonylacetone was introducedag8 as solvent for iodination at position 6 of nitrocellulose, but was quickly adoptedOQ'~1~7~147~148~a94.396 for use (see Tables 111, IV, V, IX) with sulfonic esters of sugar derivatives. Isobutyl methyl ketone357has also been used. Hudson and coworkersa7'introduced use of acetic anhydride as solvent (under reflux) for compounds37scontaining no free hydroxyl groups, and then, realizing that free hydroxyls should be protected in order to obviate successfully the possibility of glycoseen formation, also applied it168*170 to compounds containing free hydroxyl groups; a much later application3e2 of the same principle has already been mentioned (see p. 186). Soon after the appearance of Oldham and Rutherford's classic paperlZo Levene and his school began a systematic study of the behavior of cyclicsugar derivatives bearing only secondary O-sulfonyl groups. In 1933, they found that 5,6-O-benzylidene-l,2-O-isopropylidene-3-0-tosyl-~-glucose is completely unaff e ~ t e d under ~ ~ ' Oldham and Rutherford's conditions, but that the sulfonyloxy groups of 5-O-acetyl- and 5-0-benzoyl-1,2-0(393) (394) (395) (396) (1948). (397) (398)
W. Low and E. V. White, J . Am. Chern. Soc., 66, 2430 (1943). J. F. Carson and W. D. Maclay, J . Am. Chem. Soc., 70, 2220 (1948). J. Honeyman, J . Chem. Soc., 168 (1947). C. J. Malm, L. J. Tanghe, and Barbara C. Laird, J . Am. Chem. Soc., 70,2740 T. Timell, Svensk. Kem. Tidskr.,61, 146 (1949); Chem. Abstracts, 44, 325. G . E. Murray and C. B. Purves, J. Am. Chem. SOC.,62, 3194 (1940).
198
R. STUART TIPSON
isopropy~idene-3-0-tosyl-~-xy~ose slowly react with sodium iodide in acetone at 100"; the extent of this reaction is, however, negligible compared with that of a 5-tosyloxy group in D-xylose derivatives (see Table VI). Hence, the method is applicable, as a diagnostic procedure (as well TABLEV I A ~ t i o n ' ~of3 Sodium Iodide-Acetone on Tosyl Derivatives of D-Xylofuranose, at 100"
Derivative of 1,2-O-isopropyZidene-~-xylose
3-O-Acetyl-5-O-tosyl 3-O-Beneoyl-5-O-tosyl 5-O-To~yl 5-O-Acetyl-3-O-tosyl 5-O-Benzoyl-3-O-tosy1
Percent of Tosyl Group Replaced, on Heating for
32 38 67
59 62 88
6
4 5
3
as a preparative procedure) , to D-xylofuranose derivatives. The results of study of some other cyclic-sugar derivatives having only secondary sulfonyl groups are presented in Table VII. Of the 34 substances listed therein, only three (compounds 7, 9, and 20) react with sodium iodide in acetone. The faint reactivity of compound 9 may be attributable t o the acidic nature of the aglycon and to the free primary hydroxyl group a t carbon atom 5. Compound 7 shows more pronounced reactivity; it has not only an acidic aglycon but also a 2-deoxy group (which, as previously mentioned, seems to exert an activating effect, see p. 195) and a 5-O-trityl group. As regards compound 20, the extremely drastic conditions of reaction, resulting in liberation of free iodine, should be noted. When free iodine is formed, it can gradually iodinate the acetone; development of acidity is likely, and partial deacetylation might ensue, thus permitting of double-bond or anhydro-ring formation. The behavior of compound 20 needs further study. A trace of free iodine was liberated in the reaction with compound 9, possibly because of anhydroring formation with the free primary hydroxyl group. From these results, the conclusion seems justifiable that secondary hydroxyl groups attached to carbon atoms in the ring of cyclic-sugar derivatives are unreactive towards sodium iodide in acetone, except in the special circumstances mentioned. This has permitted use of the reaction for conjirmation of structures assigned from other evidence (e.g., methylation studies) and, used judiciously, as a diagnostic test for presence or absence of a primary sulfonyloxy group in related compounds. For instance, discovery that the 4-tosyloxy group of tosylated pentopyranoses,
199
SULFONIC ESTERS OF CARBOHYDRATES
TABLEVII Action” of Sodium Iodide on Cyclic-Sugar Derivatives Containing Secondary 0-Sulfonyl Groups
No,
-
Compound
-
Temp., “C.
Time, hrs.
Yield,’sc Percent
References
.~
1
Ethyl 3,40-isopropylidene-2-O-mesyl@-n-arabinoside 2 Methyl 3,4di-O-acetyl-2-0-mesyl-@-~arabinoside 3 Methyl 3,40-isopropylidene-2-O-mesyla-D-arabinoside
!25
2
210
I10
5
210
! 10
5
210 198 210 210
I10 or 13( 8 4 Methyl 3,4-0-isopropylidene-2-O-mesylI25 5 0-D-arabinoside !OO 2 5 Methyl 3,4-O-isopropylidene-2-O-tosylL 10 0-D-arabinoside 2 5 6 %ethyl 2-O-mesyl-@-~-arabopyranoside I10 2 100 35, then osyl-5-0-tri ty l-0-D8,ther 7 3 ‘-(2-Deoxy-3-0-t “ribosyl”)-5’-methyluracil
LOO, then
!, then
35
8
8 9’-(2,3-Di-O-tosyl-@-~ribofuranosy1)-N-tosyl-adenine LOO 9 3’-(2,3-Di-O-tosyl-p-~-ribofuranosyl)L 00 uracil 10 Methyl 2-deoxy-3,4-di-O-tosyl-D-~105-10 “riboside” 11 Methyl 2,3-0-isopropylidene-4O-tosylLOO D-riboside 12 4,6-O-Ethylidene-l,2-O-isopropylidene3-O-mesyl-~-galactose 130-35 13 4,6-0-Ethylidene-l,2-0-isopropylidene130-35 3-0-tosyl-~-galactose 14 Methyl 3,6-anhydro-2-O-rnesyl-a-~- 110-15 110-15 galactoside 15 Methyl 3,6-anhydro-2,4-di-O-mesyl-a110-15 D-galactoside l G Methyl 2,3,6-tri-O-benzoyl-4-0-tosyl-@LOO D-galactoside 17 Methyl 4,6-0-benzylidene-2-deoxy-3-0110-15 tosyl-a-“ D-galactoside ” 18 Methyl 2,6-di-O-methyl-3,4di-O-tosyla,B-D-galactoside LOO 19 Methyl 4,6-di-O-methy1-2,3-di-O-tosylLOO 0-D-galactoside 20 1,2,3,6-Tetra-0-acetyl-4o-mesyl-~- 135 glucose
-
198 210 ,110
2
111
26
107
3
274
2
207
0
399
0
399
5 LO
5
.169 169 216
5
354
2
400
213 ’0-72d
.24
200
R. STUART TIPSON
-
TABLEVII (Continued)
No.
1 I
Compound
Temp., "C.
Yield,bsc ReferPercent encea
Time, hrs. ~~
21 lJ6-Anhydro-2,3,5-tri-0-tosyl-~-~100 glucose reflux 22 1,2:5,6-Di-O-cyclohexylidene-3-0phenylsulfonyh-glucose reflure 23 6-O-Acetyl-l120-isopropylidene-5-0100 tosyI-D-glucose 24 lJ2-O-Isopropylidene-3-O-mesyl-~ 100 glucose 5,Bcarbonate 25 42:5,6-Di-O-isopropylidene-3-0-tosyl-~-100 glucose 26 Methyl 2,3,6-tri-0-benzoyl-4-O-tosyl-cu100 D-ghcoside 27 Methyl 3,5,6-tri-0-benzoyl-2-O-tosyl-~n-glucoside 100 28 Methyl 4,6-0-benzylidene-3-deoxy-2-0tosyh-D-" glucoside l J 140 29 Ethyl 2,3,6-trideoxy-4-0-mesy1-a-~"glucoside " 115-20 30 7'-(4,6-0-Bensylidene-3-~-tosyl-~-~glucosy1)-theophylline 110 31 1,3:2,4Dianhydro-5-O-tosyI-ketohexopyranosazone 100 32 Methyl 4,6-0-benzylidene-3-deoxy-2-0tosyl-cu-D-"mannoside " 140 33 Methyl 6-deoxy-2,3-0-isopropylidene-P 0-tosyl-bmannoside 100 34 Methyl &deoxy-2,3-0-isopropylidene-5100 0-tosyl-kmannoside 0
Unlesa otherwise stated, acetone was the solvent.
6
of sodium sulfonate, for removal of one sulfonyloxy group.
2 2 14d7
Ob
decomp 7 Ob
401 }227
2
34
5 2
402 20, 368
2
260
2
34
1
403
5.5
356
6
149
15
404 289
2
405
2
406
Yield of deoxyiodo-sugar derivative. 0 Yield 1 Free iodine liberated. a Acetic anhydride.
(399) A. B. Foster, W. G. Overend, and M. Stacey, J. Chem. SOC.,980 (1951). (400)E.T. Dewar and E. G. V. Percival, Nature, 166,633 (1945);J. Chem. Soc., 1622 (1947). (401)R. J. Dimler, H. A. Davis, and G. E. Hilbert, J. Am. Chem. SOC.,68, 1377 (1946). (402) W. G.Overend, M. Stacey, and L. F. Wiggins, J. Chem. Soc., 1358 (1949). (403) D. A. Prins, Helv. Chim. Acla, 29, 1 (1946). (404)E. G. V. Percival, J. Chem. SOC.,1384 (1938). (405) P. A. Levene and I. E. Muskat, J. Biol. Chem., 106, 431 (1934). (406) P. A. Levene and I. E. Muskat, J. Biol. Chem., 106, 761 (1934).
SULFONIC ESTERS OF CARBOHYDRATES
201
and the 2- or 3-tosyloxy groups of tosylated pentoses, are replaced by iodine with difficulty, whereas the 5-tosyloxy group of tosylated pentofuranoses is readily replaced, permitted confirmatory and diagnostic use902of the reaction in elucidating the furanose ring structure of, and positions of substituents in, derivatives of D-ribose- and 2-deoxy-~‘ribose ’’-(2-deox y-n-erythro-pent ose-)nu cleosides. b. Secondary Sulfonyloxy Group Contiguous to Primary Sulfonyloxy Group in Alditols and Aeyelie-Sugar Derivatives.-In 1937, Levene and Mehltretter407“found that the tosyl[oxy] group was removed with equal ease from the primary and from the secondary carbon atoms” of D,L-~-Omethyl-2,3-di-0-tosyl-glyceritol and 1,2,3-tri-0-tosyl-glyceritol under Oldham and Rutherford’s conditions, but unfortunately did not appreciate the fundamental significance of their observation (though they realiaed that, as a diagnostic tool, the method was inapplicable to their immediate problem). In 1943,Tipson and Cretcheras8made a discovery which provided the explanation for Levene and Mehltretter’s observation: on treating 1,2,3,4-tetra-0-tosyl-erythritol with Finkelstein’s reagent (during 2 hours a t 100”), 91% of the amount of sodium p-toluenesulfonate required by removal of all four tosyloxy groups was isolated, and free iodine and butadiene were recognized as the other products. (
CH~OTS I
H ~ O T ~ H OTs
+4NaI+
I
~H~OTS
CHI I1
&H
AH
+21~+4NaOTs
11
bH2
Furthermore, the tosyloxy groups were found to be so reactive that the reaction could be performed in boiling acetone under reJIux, affording the following yields of sodium p-toluenesulfonate: 41 % (2 hrs.); 50.5% (4 hrs.); and 74.5% (12 hrs.). Attention was drawn368 t o the f a ~ t ~ ~ ~ , ~ o * ( I that diiodo compounds having the iodine atoms attached a t adjacent carbon atoms cannot be prepared by the action of sodium iodide in acetone on the corresponding dichloro or dibromo derivatives, since the diiodo compounds readily lose iodine to form unsaturated substances ”; this observation was, incidentally, probably first made by Perkin40gin 1871. Tipson and C r e t ~ h e ralso ~ ~ *pointed out that OIdham and Rutherford’s Rule (see p. 192) ‘(cannot be extended t o the tosyl esters of sugar alcohols” and that such attempted applications had probably led t o erroneous conclusions (a comment since amply justified, see p. 189), and (407) P. A. Levene and C. L. Mehltretter, Enzymologia, 4, 232 (1937). (408) E. Hiilmann, Rec. tmv. chim., 56, 313 (1916); 57, 245 (19181. (409) W. H. Perkin, J . Chenl. Soc., 24, 37 (1871).
202
R. STUART TIPSON
they suggested that ' I the method might prove of use in the preparation of certain unsaturated hydrocarbons from the corresponding sugars, through the sugar alcohols." TOLE VIII Actiona of Sodium Iodide on Alditol Derivatives Having a Secondary Sulfonyloxy Group Contiguous to a Primary Suljonyloxy Group
No 1
2 3 4
5 6
7 8 9
-
Compound
Temp., Time, Yield,b-cJ Referhrs. Percent ences "C. __-
3,6,-Anhydro-4,5-0-isopropylidene-1,2-di-Omesyl-D-mannitol 100-105 3,6-Anhydro-4,5-O-isoprop ylidene- 1,2-di-0- 100-105 tosyl-n-mannitol 125-30 3,4-O-Cyclohexylidene-l,2,5,6-tetra-O-tosylD-mannitol 100-10 1,2:3,4Di-O-isopropylidene-5,6-di-O-mesylD-mannitol 100 1,2:3,4-Di-O-isopropylidene-5,6-di-O-tosyI-~mannitol reflux reflux 1,2,5,6-Tetra-O-tosyl-n-rnannitol 1,3:2,4-Di-O-benzylidene-5,6-di-O-tosylsorbitol 1,3:2,4-Di-O-ethylidene-5,6-di-O-mesylsorbitol 100 1,3:2,4-Di-O-ethylidene-5,6-di-O-tosyl100 sorbitol
1.5"
-43.3c 168
1.5e 4' 8'
93.Sd 410
8.58
65.5b 411 215 215
fP
369 6" 6"
lOOc 73b lO0c
411
} 411
4 In acetone. b Yield of glycoseen derivative. 0 Yield of sodium sulfonate, for removal of two sulfonyloxy groups. d Yield of sodium sulfonate, for removal of four sulfonyloxy groups. e Free iodine liberated.
Several other examples of this kind of behavior have since been accumulated (see Table VIII). The depressant effect of a 3,6-anhydro ring is seen in compounds 1 and 2. I n reference t o compound 5, the strange procedure adopted216 consisted in boiling the solution under reflux, with periodical cooling followed by filtration of accumulated sodium p-toluenesulfonate (NaOTs) and reheating. The reaction mixture presumably became moist and then acidic, because the product had lost the isolated (~-mannitoleen-5,6or 5,6-didehydroxy-~-mannitol) original isopropylidene groups : (410) E.J. Bourne, W. M. Corbett, and D. Erilinne, J. Chem. Soc., 786 (1950). (411) P. Bladon and L. N. Owen, Nature, 163, 140 (1949); J. Chem. SOG.,598 (1950).
203
SULFONIC ESTER13 OF CARBOHYDRATES
CHzOH
A
HO H HCOH
I
HC
I
II
CHZOTS
CHz
Very little of this “deacetonated” material was obtained when the corresponding 5,6-0-mesyl derivative (compound 4) was treated411 in the customary manner. As regards compound 6 (Table VIII), the procedure of Karrer and Davis216led to partial “acetonation”: TsOHzC
CII 2
CHz
‘I’sOkH
CH
CH
HobH
HOAA
H OH
AI
H OTs
II
- 1 :I
II I
+ I&-/
OCH
H OH
HCOd
CH
CH
CH 2
CH,
I
II
CH20Ts
II
The suggestion had been made369that these reactions proceed as follows : -CHOTs-CHjOTs
+ -CHOTS-CH~I
+
[-CHI-CH21]
-CH=CH*,
i
but recent experiments382 indicate that formation of the hypothetical dideoxy-diiodo derivative may not actually occur. Instead, it appears likely that anionic attack a t the primary carbon atom of A results in the iodine-exchange reaction to give B; then, anionic attack a t the iodine I
TsOCH I‘ 4 HI z O T s A
TsO?&I 7
CHS-I -1 +I’ B
-
I TsO’ CH II CHs C
+ 1s
atom of B brings about an intramolecular displacement, with consequent release of the tosylate ion from B, liberation of molecular iodine, and ~ ~ ~demonstrated that step formation of c . Foster and O ~ e r e n dhave (B + c) proceeds more readily than step (A 4 B); thus, step (B -+ c ) for 3,6-anhydro-l-deoxy-l-iodo~,5-0-isopropylidene-2-O-tosyl-~-manni-
204
R. STUART TIPSON
to1 is not effected by acetone alone (4 hours at 130-35"), but i s brought about not only by sodium iodide (yield of NaOTs, 95.1%) but also by sodium trifluoroacetate (yield of NaOTs, 96.5 %) and by sodium salicylate (yield of NaOTs, 91.7%), with formation, in all these cases, of 3,6anhydro-4,5-0-isopropylidene-~-mannitoleen-1,2 plus free iodine. A similar mechanism undoubtedly accounts382for the analogous case (see pp. 186 and 196) of the grouping -CHOH.CH20Ts, as follows: HO-CH q'
HOCK 1 I
It+ CHlOTs
&-I
+I'
-
I II
HO' CH CHI
+ 11
because treatment of 3,6-anhydro-4,5-0-isopropylidene-l-0-tosyl-~-mannitol affords the 1-deoxy-1-iodo derivative which, on further treatment during 12 hours a t 210-20", gives 3,6-anhydro-4,5-0-isopropylidene-~mannitoleen-1,2 plus free iodine. A compound which might be expected to react according to the forehowgoing scheme is 1,3-0-ethylidene-2,4,5,6-tetra-0-tosyl-~-mannitol; ever, on treatment378with sodium iodide-acetone during 8 hours at 100-lo", only 97% of the sodium p-toluenesulfonate which should be formed on removal of one tosyloxy group was isolated; this might represent 48.5% removal of two tosyloxy groups (at carbon atoms 5 and 6). Appropriately substituted derivatives of acyclic sugars should behave in the same manner as the alditols. The only examples so far studied are2362,3-di-0-tosyl-~,~-glycerose and its diethyl acetal, which react as follows : CHO AHOTs
+
&€LOTS
CHO
CH(OEt)Z
GH
I
~ H O T B -+ CEI
CH2
AH.DTs
II
CH(0Et)r
I /I
CH?
to yield free iodine plus acrolein and acrolein diethyl acetal, respectively, during 2 hours at 50". 3-O-Tosyl-~,~-glycerose diethyl acetal was said236 to give rise to the corresponding 3-deoxy-3-iodo derivative, but this was not characterized. c. Secondary Sulfonyloxy Group Non-contiguous to Primary Sulfonyloxy Group, in Aldito1s.-In compounds of this type, the primary sulfonyloxy groups are much more reactive than the secondary, so that preparation of w-deoxy-w-iodo derivatives is feasible. Thus, treatment of 2,3 :5,6-di-O-isopropylidene-1,4-di-0-tosyl-~,~-galactitol with sodium iodide-acetone (during 90 minutes at 100") yields27sthe corresponding 1-deoxy-1-iodo-4-0-tosyl derivative; similarly, 2,4-0-methylene-1,3,5tri-0-tosyl-ribitol gives, by treatment in acetonylacetone (during 24 hours at SO"), a quantitative yield26Eof 1,5-dideoxy-l,5-diiodo-2,4-0-
205
SULFONIC EBTERS O F CARBOHYDRATES
methylene-3-0-tosyl-ribitol. The 2,5-0-methylene-l,3,4-triand -1,3,4,6tetra-0-tosyl derivatives of 6-deoxy-~-mannitol and of D-mannitol, respectively, giveZ61 the corresponding l-deoxy-l-iodo-3,4-di-0-tosyl and 1,6-dideoxy-l,6-diiodo-3,4-di-0-tosyl derivatives. d . Secondary Sulfonyloxy Group Contiguous to Primary Sulfonyloxy compounds of this type, the Group, in Cyclic-Sugar Derivatives.-In reactive sulfonyloxy groups are on carbon atoms attached as an alditol chain to the sugar ring. Hence they behave Like the corresponding derivatives of alditols (see Section V I 2b, page 201). Examples are methyl 2,3-anhydro-5,6-di-0-tosyl-/3-~-alloside~~~ and l12-0-isopropylidene-5,6-di-0-tosyl-~-glucose,118 Such compounds cannot, of course, be -1
HCO, HbO/IP HOAH
c:I
H 0-
+ 2 NaI+
HOAH HA0
1+
2 NaOTs
+ IZ
I
HCOTs ~HzOT~
provided by aldotrioses, aldotetroses, and aldopentoses; and the aldoheptose derivatives (whose behavior would be highly interesting) have not, as far as is known, been so tested. The aldoheptofuranose derivatives would have a 3-carbon “tail,” and the aldoheptopyranoses would have the above 2-carbon “tail.” Ketose derivatives of this kind have not, apparently, been studied. e. Secondary Sulfonyloxy Groups ( O n l y ) , in Sulfonylated Alditols and Aldonic Acids.-Attention has already been drawn to two steric influences which may modify the reactivity of a primary sulfonyloxy group towards sodium iodide, viz., (a) the nature of the group o n the conliguous carbon atom (free hydroxyl, carboxylic ester, acetal ring, anhydro ring, or sugar ring), and (b) conjigurational differences in the molecular moieties to which the primary carbon atom is appended, resulting in spatial proximity of the primary sulfonyloxy grouping to differing influences. These two factors are also operative in affecting the reactivity of a secondary sulfonyloxy group towards sodium iodide, but consideration of the evidence already presented indicates that, for secondary groups, a third efect must also be superimposed in certain instances. In order to ascertain what this third effect might be, Tipson, Clapp, and Cretcherae4 intercompared the reactivity of various kinds of secondary tosyloxy group, and compared these reactivities with those of primary tosyloxy
206
R. STUART TIPSON
groups, in model experiments on a number of rather simple esters of p-toluenesulfonic acid. They discovered304that, if a primary tosyloxy group is appended to a six-membered carbon ring, it may be much more reactive than when attached to a carbon chain. Thus, after action of sodium iodide-acetone during 2 hours at room temperature, benzyl p-toluenesulfonate gave a 97% yield of sodium p-toluenesulfonate (NaOTs), whereas n-propyl p-toluenesulfonate (which might be regarded as 2,3-dideoxy-I-0-tosyl-"glycerito111) gave only a 49.5% yield of NaOTs. Furthermore, as the length of the carbon chain was increased, the reactivity of the primary sulfonyloxy group decreased (methyl, 96.5;ethyl, 51, n-propyl p-toluenesulfonate, 49.5% of NaOTs); and an ether linkage further decreased the reactivity (P-ethoxyethyl, 14.5; P-phenoxyethyl, 12; 0-benzyloxyethyl p-toluenesulfonate, 13% of NaOTs). Hydroxylation a t carbon atoms of the chain further reduces the reactivity of the primary sulfonyloxy group. Secondly, they found304that, if a secondary tosyloxy group is attached to a carbon atom in a chain having few or no attached hydroxyl groups, it may be surprisingly reactive, to a degree not hitherto suspected, towards sodium iodide-acetone. (This finding is actually the corollary of the previous discovery that a methylene group may enhance the reactivity of a sulfonyloxy group.) Furthermore, some secondary tosyloxy groups were found to be more reactive than some primary tosyloxy groups. Thus, at 25", O-tosyl-diethyl carbinol (1,2,4,5-tetradeoxy-3-O-tosyl-pentitol) gave 23 and 85% yields of NaOTs after 2 and after 24 hours, respectively, whereas O-tosyl-P-ethoxy-ethanol gave only 14.5 and 68% yields. Increase in the chain length, symmetrically, increased the reactivity of the secondary tosyloxy group (p-toluenesulfonic ester of dimethyl carbinol, 7.5; of diethyl carbinol, 23; of di-n-propyl carbinol, 24 % of NaOTs, after 2 hours a t 25"). In contrast, a secondary tosyloxy group attached to a carbon atom engaged in a 6- or 6-membered ring (see Tables V, VI, VII) is relatively unreactive. Thus, cyclohexyl p-toluenesulfonate, under the above HzC-CHa
HnC/
\
HzC-CHI
'CHOTf3
/
conditions, gave only 3 and 15% yields of sodium p-toluenesulfonate (but a 98% yield after 2 hours at 100"); because of adjacency of a reactive methylene group, free iodine was also liberated. Hence, the nature of the third depressant of reactivity was revealed. (It is obvious that this factor cannot be operative with a primary sulfonyloxy group, since such a group cannot be attached to a carbon atom in a ring.)
207
SULFONIC ESTERS OF CARBOHYDRATES
TABLEIX Action0 of Sodium Iodide on Secondary Sulfonyloxy Groups (Only) in Sulfonylated Alditols
No.
Temp., Time, Yield,bsc References "C. hrs. Percent
Compound N o Ring
2 1,3,4,6-Tetradeoxy-2,5-di-O-tosylergtho(?)-hexitol (or No, 3) 3 1,3,4,6-Tetradeoxy-2,5-di-O-tosylD,Irthreo(?)-hexitol (or No. 2)
2 2.5
reflux reflux
0
lOOb
365 179 179
I00
7
89"
157
100
8
100c
157
95- 100
1 1-0-Beneoy1-3-deoxy-2-0-tosylg1y cerito1
2 4 1,3,4,6-Tetra-O-acety1-2,5-di-O-tosyl1 15-20' 3 dulcitol 100-103 135-40
412
88C 45c
412
110
tosyl-D-mannitol 8 1,6-Di-O-phenyl-2,5-di-O-tosyl-~mannitol
100 100
9 1,2,3,4-Tetra-O-acetyl-6-O-benzoyl-5-
100-103 Outside The Ring(s) 10 3,6-Anhydro-l-deoxy-4,5-O-isopropylidene-2-O-tosyl-~-mannitol 110-15 11 3,6-Anhydro-4,5-O-isopropylidene1-0-methyl-2-0-tosyl-~-mannitol 125-30 12 1,2,6-Tri-O-beneoyl-3,4-O-beneylidene-100-103 5-O-tosyl-~-mannitol 135-40 13 1,6-Di-0-ben~oyl-3,4-0-isopropylidene-100-103 2,5-di-O-tosyl-~-mannitol 115-20 110 1,2 :5,6-Di-O-isopropylidene-3,4-di-O- 100 :5,6-Di-O-isopropylidene-3,4-di-O14 1,2 mesyl-D-mannitol mesyl-D-mannitol 100,then 125-35 0-tosyl-sorbitol
I
15 1,2:5,6-Di-O-isopropylidene-3,4-di-Otosyl-D-mannitol
412
4
100-103 2 100-103 2 1 15-20 3
5 2,5-Di-O-tosyl-dulcitol 6 3,PDi-O-acetyl-l,6-di-O- beneoyl2,5-di-O-tosyl-~-mannitol 7 1,6-Di-O-beneoyl-2,3,4,5-tetra-O-
0
30 30, then
110
16 3,4-O-Isopropylidene-1,6-di-O-phenylLOO 2,5-di-O-tosyl-~-mannitol 100-103 17 6-0-Beneoyl-1,3 :a,Pdi-O-ethylidene1 15-20 5-0-tosyl-sorbitol 135-40 18 1,3:2,4-Di-O-ethylidene-6-O-o-tolyl-5105-10 0-tosyl-sorbitol
76,77 8
0
6
slight
2
57b
412
4
0
381
0
0
381
2 4 2
2
]
157
412 1I C 54c 0
]
5d 5,then 15d 2 2,then 12d 1o o c 7.5 2
0 0
3
4
82b 1OOb
7
0
412 411
411
]
157 412 157
208
R. STUART TIPSON
TABLH IX (Continued)
-
No.
Temp., "C.
Compound
Inside the Ring(s) 19 1,3-O-Benzylidene-2-O-tosyl-glyceritol 100-103 20 1,3:4,6-Di-O-bensylidene-2,5-di-Otosyl-dulcitol reflux' 21 1,3:4,6-Di-O-methylene-2,5-di-Otosyl-dulcitol reflux* 22 1,4:3,6-Dianhydro-2,5-di-O-mesyl-~iditol 110-20 23 1,4:3,6-Dianhydr0-2,5-di-O-tosyl-~- 115-20 iditol 135-40 24 1,4:3,6-Dianhydro-2,5-di-O-mesyl-~mannitol 110 25 1,4:3,6-Dianhydro-2,5-di-O-tosyl-~110 mannitol 26 6-Deoxy-l,3 :2,5-di-O-methylene-4-0tosyl-L-mannitol LOO 27 1,3:4,6-Di-O-ethylidene-2,5-di-O-tosylD-mannitol 100-105 28 1,3:4,6-Di-O-methylene-2,5-di-O-tosylD-mannitol 140* 29 1,4:3,6-Dianhydro-2,5-di-O-mesylsorbitol 125 120 30 1,4:3,6-Dianhydr0-2,5-di-O-tosyl140, sorbitol reflux0 31 I,3:4,6-Di-O-methylene-2,5-di-O-tosyl100 D-talitol 3Of
1
-
Time, hrs.
Yield,bse References Percent
2
100b
412
1
0
87
0.5
0
413 1
8 3 4
4.lb
8
100c
3.5
33b
414
}
412 414
I { (i:,
loot
2
0
251
6
0
378
0
383
25'
414
2 6 3 5 2 18
22b
)
0 O
}
416)
417 384
4 Unless otherwise noted, acetone was the solvent. 1 Yield of sodium sulfonata. for removal of one eulfonyloxy group. Yield of sodium sulfonate, for removal of two aulfonyloxy pl'oupa. d Free iodine liberated. * Acetic anhydride. Acetonylacotone.
(412) N. K.Matheson and S. J. Angyal, J . Chem. SOC.,1133 (1952). (413) R. M. Ham, W. T.Haskins, and C. S. Hudson, J. Am. Chem. Soc., 64,986 (1942). (414)L. F. Wiggins and D. J. C. Wood, J. Chem. SOC.,1180 (1951). (415) P. Brig1 and H. Griiner, Ber., 67, 1582 (1934). (416) R. C.Hockett, H. G. Fletcher, Jr., ElizabethL. She5eld, R. M. Goepp, Jr., and S. Soltzberg, J . Am. Chem. Soc., 66, 930 (1946). (417)R.C.Hockett, H. G. Fletcher, Jr., Elizabeth L. Sheffield, and R. M. Goepp, Jr., J. Am. Chem. SOC.,68, 927 (1946).
SULFONIC ESTER8 OF CARBOHYDRATES
209
In order to determine whether these principles hold good when extended to alditols, some of their sulfonic esters have been collected into three groups in Table IX, which shows their behavior towards sodium iodide. I n the first group (compounds 1 to 9), there is no ring involved with the configurational chain of carbon atoms, and all members react to a greater or lesser extent. The least reactive (compound 8) has phenyloxy groups on the carbon atoms contiguous to the sulfonyloxy groups (the phenoxymethyl group had previously been shownae4to exert a depressant effect on reactivity) ; next in reactivity are compounds with acyl groups on the carbon atoms contiguous to the sulfonyloxy groups (compounds 1,4,6,7,9), the effect of which is strikingly evident on comparing compounds 4 and 5. The only compound (in this group) possessing vicinal” tosyloxy groups (compound 7) presumably reacts as follows : CHZOBZ TsOI HHZ O B Z
AH
TsdH
AH
HhTs
‘HA
HhTs AH20Bz
HA AHzOBz
The second group (compounds 10 to 18) consists of compounds having acetal rings or anhydro rings, or both. When both types of ring are present (compounds 10 and ll), the tosyloxy groups are highly unreactive. 6-0-Phenyl (compound 16) and 6-0-o-tolyl (compound 18) groups also cause negligible reactivity. In the third group (compounds 19 to 31), the sulfonyloxy groups are attached to carbon atoms in an acetal ring or a n anhydro ring. The 5-membered acetal ring of compound 19 has no depressant effect as compared with compound 1. But the presence of two acetal rings (compounds 20, 21, 26, 27, 28, 31) causes complete suppression of reactivity. The effect of anhydro rings obviously depends on the configurational disposition. Thus, in compounds 24 and 25, 100% replacement of both sulfonyloxy groups is achievable given sufficient time for reaction; but, in the L-iditol derivatives (compounds 22 and 23), the reactivity is low; and, in the sorbitol derivatives (compounds 29 and 30), one of the two sulfonyloxy groups is replaced, with formation of isolable deoxyiodo-0sulfonyl derivatives. By inspection of molecular models, Matheson and Angya1412 have found a plausible explanation for these observations. The three anhydrides, which differ only in the configurations a t carbon atoms 2 and 5, all have two fused 5-membered rings inclined to each other
210
R. STUART TIPSON
t o give a V-shaped molecule. In attack by a negative ion, with reaction by the SN2mechanism, there is approach of the entering atom to that face of the carbon atom opposite to the group to be displaced, and “if that face is on the inside of the V, the attack is sterically hindered.” In the D-mannitol derivative, there is no steric hindrance because both tosyloxy groups are attached to the inside of the V; in the sorbitol derivative, the reaction is obstructed at carbon atom 2, but not a t carbon atom 5; but in the L-iditol derivative both tosyloxy groups are on the outside of the V, and so approach to the opposite sides of the carbon atoms is impeded. One sulfonylated aldonic-acid derivative of this type has been tested, viz., methyl 2,4:5,6-di-0-methylene-3-0-tosyl-~-gluconate. On treatment41s with sodium iodide-acetone a t 100” it gave free iodine plus sodium p-toluenesulfonate (50%, 2 hours; 57%, 4 hours). If heated with sodium iodideacetic anhydride under reflux for 2 hours, a 98% yield of sodium p-toluenesulfonate resulted. What contribution the carbomethoxy group makes is, as yet, unknown; but there is reason t o believe131 that it may be considerable.
3. A pplicabilitg of Oldham and Rutherford’s Rule From the foregoing appraisal of the results accumulated to date, it is seen that Oldham and Rutherford’s Rule applies to derivatives of aldopentofuranoses and aldohexopyranoses, and, presumably, of aldoheptoseptanoses. If such compounds bear additional rings, the ease of reaction of the primary sulfonyloxy group is lessened, and this effect is greater with anhydro rings than with acetal rings. Consequently, for both diagnostic and preparative purposes, rupture of these rings, followed by acetylation of all free hydroxyl groups, may often be advisable (if feasible) prior to treatment with sodium iodide. The (separate) acetylation step may often be obviated by performing the iodination with sodium iodide in acetic anhydride. Oldham and Rutherford’s Rule does not apply to, nor was it propounded for, non-cyclic alditol derivatives. Neither does it apply to that part (if any) of a cyclic-sugar molecule which is actually an appended, non-cyclic alditol chain. Thus, it does not apply to carbon atoms 5 and 6 of an aldohexofuranose; nor, presumably, t,o carbon atoms 6 and 7 of an aldoheptopyranose or carbon atoms 5, 6, and 7 of an aldoheptofuranose. Because carbon atom 2 of cyclic-ketose derivatives is engaged in acetal or hemiacetal rings, the Rule does not here apply to a l-sulfonyloxy group, but is applicable to the other primary sulfonyloxy group (if any) (418) C. L. Mehltretter, R. L. Mellies, and C. E. Rist. J . Am. Chem. Soc., 70, 1064 (1948).
SULFONIC ESTERS O F CARBOHYDRATES
211
and to secondary sulfonyloxy groups. Therefore, it presumably does not apply to appended, non-cyclic alditol chains, as a t carbon atoms 6 and 7 of a ketoheptofuranose. As a result of these considerations, a rejuvenescence of interest in sulfonic esters of acyclic-sugar derivatives, e.g., of sugar mercaptals, is to be expected, since they afford a route to the synthesis not only of compounds having one or more methylene groups a t desired positions in the sugar chain (of which 2-deoxy-~-''ribose," or 2-deoxy-~-erythro-pentose, is a conspicuous example) but also of compounds having other groupings, e.g., double bonds, a t selected positions in the chain. Finally, it seems astounding that a greater variety of sulfonic radicals (attached to sugars and alditols) have not been tested in relation to ease of desulfonylozylation. There can be little doubt that, in this regard, p-nitrophenylsulfony18sogroups would prove superior t o tosyl or mesyl groups (since, for p-substituents on the benzene ring, the order of increasing reactivity of their ethyl esters isagop-CHSO < p-CH3 < p-H < p-Br < p-NOz), and 2,4-dinitrophenylsulfonyl groups might be even more efficacious. 4. Action of Other Alkali-Metal Halides on Sulfonic Esters Potassium bromide,341 sodium br0mide,306,33~and sodium chlorideSS5 have been used for preparing alkyl halides from the corresponding sulfonic esters, but the yields were not as good336as for the iodides. These reagents have not, apparently, been applied to sulfonic esters of carbohydrates. Lithium bromide was used for convertingz3a2,3-0-isopropylidene-l-O-tosyl-D,L-glyceritolinto the corresponding l-bromo-l-deoxy derivative, by refluxing in acetone for 2 hours. Lithium chloride, preferably dissolved in absolute ethanol, has also been ~ s e d ~for ~preparing ~ * ~alkyl ~ chlorides. ~ , ~ ~ Dissolved ~ in absolute ethanol-acetone (1: 1, by vol.), it has recently4l4 found application with alditol sulfonates. Its action on 1,4:3,6-dianhydro-2,5-di-O-mesyl-~iditol, 1,4:3,6-dianhydro-2,5-di-O-mesyl-~-mannitol~ and 1,4:3,6-dianhydr0-2~5-di-O-mesyl-(and -2,5-di-O-tosyl-) sorbitol resembles the action of sodium iodide on these compounds, i.e., the first displays no appreciable reaction, the second gives the 2,5-dichloro-2,5-dideoxyderivative, and the last two afford the respective monochloromonodeoxy-mono-0sulfonyl derivatives. Treatment of 1,4:3,6-dianhydro-2,5-di-O-mesylsorbitol during 48 hours a t 180-90" gives some of a dianhydro-monochloromonodeoxy-sorbit oleen. (419) J. Kenyon, H. Phillips, and G. R. Shutt, J . Chem. SOC.,1663 (1935). (420) Cf.,P. D. Bartlett and L. H. &ox, J . Am. Chem. SOC.,61, 3184 (1939).
212
R. STUART TIPBON
Potassium fluoride (dihydrate) reacts421 with 6-O-mesyl-~-glucose derivatives to form the corresponding 6-deoxy-6-fluoro compounds. Since the reagent is alkaline, it is important that the other hydroxyl groups be first protected by substituents not hydrolyzable by alkali. Treatment421 of 3,5-0-benzylidene-l,2-0-isopropylidene-(i-O-mesyl-~-glucose with the reagent in absolute methanol, in a sealed tube during 15 hours a t 100°, affords a 96% yield of the 6-deoxy-6-fluoro derivative, but the corresponding 6-O-ethylsulfonyl derivative is said to be18 unreand methyl active. 1,2-0-Isopropyl~dene-3,5,6-tr~-~-mesy~-~-g~ucose~~ 2,3,4,6-tetra-0-mesyl-cu-~-glucoside~~~ also give the corresponding 6-deoxy6-fluoro derivatives, but, as might be expected, 5,6-0-benzylidene-l12-0isopropylidene-3-0-mesyl-~-g~ucose~~ is unreactive.
VII. ACTIONOF OTHERSALTSON SULFONIC ESTERS Just as silver fluoride in dry pyridine converts346methyl 2,3,4-tri-Oacetyl-6-deoxy-6-iodo-~~-~-glucoside to the corresponding glucosideen-5,6, so it transforms240methyl 4-0-acetyl-6-deoxy-6-iodo-2,3-di-0-tosyl-/3-~glucoside to the glucosideen-5,6, without affecting the secondary tosyloxy groups. The same reaction may be applied' to 6-deoxy-6-iod0-2,3-di-Otosyl-starch. However, the effect on primary sulfonyloxy groups does not appear to have been studied. Sodium nitrite reacts341 with methyl and ethyl p-toluenesulfonates to yield nitromethane and nitroethane, respectively. No study of its effect on other sulfonic esters has been encountered. Potassium cganide has been caused to react with salts and esters of sulfonic acids t o give nitriles. Thus, an intimate mixture of finely powdered potassium cyanide with the compound may be fused;422this method was successfully applied423t o tetrahydrofurfuryl p-toluenesulfonate and methanesulfonate, but failed with 1,2:3,4-di-O-isopropylidene6-O-tosy~-~-gaiactose.Another method, consisting of treatment of the ester with a stirred, boiling, saturated, aqueous solution of potassium cyanide gaves35a 70 to 83 % yield of nitrile with primary p-toluenesulfonates (ethyl, n-butyl, and n-octyl) and a 43% yield with a secondary p-toluenesulfonate (isopropyl). Similar methods had been applied earliersala41to such,simple esters, but have not apparently found use with sulfonic esters of carbohydrates. Potassium thiocyanate has been employedso5somewhat more extensively. Thus, it was found to react424with the secondary tosyloxy group (421) (422) (423) (1946). (424)
B. Helferich and A. Gniichtel, Ber., 74, 1035 (1941). V. Merz and H. Miihlhiiuser, Ber., 3, 709 (1870). M. Zief, H. G. Fletcher, Jr., and H. R. Kirshen, J . A m . Chem. Soc., 68, 2743
W. Gerrard, J. Kenyon, and H. Phillips, J . Chem. Soc., 153 (1937).
213
SULFONIC ESTERS O F CARBOHYDRATES
of ethyl a-tosyloxypropionate, by refluxing in ethanol for 6 hours, to give ethyl a-cyanothiopropionate. (Under the same conditions, potassium selenocyanate gave424ethyl a-cyanoselenopropioinate.) The first application of potassium thiocyanate t o sulfonic egters of sugars was made426in with the 1941. Orl. treating 1,2,3,4-tetra-0-acety~-6-0-tosy~-~-~-glucose reagent in acetone, in a sealed tube during 10 hours a t 130°, a 47% yield of the corresponding 6-cyanothio-6-deoxy derivative wm isolated; the new substituent is quite stable since, by successive treatment with hydrogen bromide in acetic acid (see p. 148) and with methanol plus silver carbonate (see p. 153), methyl 2,3,4-tri-O-acetyl-6-cyanothio-6deoxy-8-D-glucoside was obtained. The latter compound also resulted on treatink methyl 2,3,4-tri-0-acety~-6-0-tosy~-~-~-glucoside with potassium thiocyanate as above, and the corresponding a-D-glucoside gave a 79 % yield of methyl 2,3,4-tr~-0-acetyl-6-cyanothio-6-deoxy-o-~-glucoside. By treating a cyanothio-deoxy derivative with sodium methoxide, a bis-(6-deoxy-glycose) disulfide results: HhOJ
AHzOTs (IzBcN!
A
Ha:2-,
LJ --(!JHc (MeONa)
H 0
I
CHz-&S--
HI
As might be expected, a secondary sulfonyloxy group in cyclic sugars proved unreactive; thus, the reagent W&F) without &ect on methyl 2,3,6-tri-0-acetyl-4-O-mesyl-(or -&O-tosyl-)P-D-glucoside, and on 1,2:5,6-di-0-isopropylidene-3-O-mesyl-(or-3-O-tosyl-)D-glucose. However, in view of the fact that the secondary sulfonyloxy group of cholesterol tosylate reacts426to give the cyanothiodeoxy derivative, there is no reason to believe that the same replacement will not be accomplishable n hen the reaction is applipd to acyclmic sugars and acyclic alditols of the types previously discussed. Sodium thiocyanate has been appliedaQ4to the tosylation products of potato starch, cellulose, guar mannogalactan, and of the hemicelluloses of corn (maize) cobs and lima-bean pods, by treating in acetonylacetone at 110-12" for 3 to 12 hours. Partial replacement of secondary tosyloxy groups in the two hemicellulose~~~~ was observed. The reagent has also been applied8' to tosylated hydroxyethylcellulose. By the actionlxOof sodium thiocyanate in acetonylacetone on 2,4:3,5-di-O-methylene-l-O-tosyl-~,~-xylitol, during 46 hours at 120°, a 91.5% yield of sodium p-toluenesulfonate plus an 87% yield resulted. By of l-cyanothio-l-deoxy-2,4:3,5-di-0-methylene-~,~-~yl~tol treatment with sodium methoxide, this gave the corresponding disulfide18" which, by reductive desulfurization, afforded 1-deoxy-2,4 :3,5-di-0(425) A. Miiller and Adrienne Wilhelms, Be?., 74, 698 (1941). (426) A. Miiller and E. Bgtyka, Be?., 74, 705 (1941).
214
R. STUART TIPSON
methylene-D,L-xylitol. This represents a new route, an alternative to the iodination and reductive deiodination procedure (see p. 157), for passing from an w-sulfoayloxy to an w-deoxy derivative. In 1925, Kenyon, Phillips, and Turleyso6observed that potassium acetate427 reacts readily with ethyl a-tosyloxypropionate t o give the a-0-acetyl derivative. In 1933, sodium acetate in boiling acetic anhydride was applied" to replacement7v of tosyloxy groups of alditols by acetoxy groups (see p. 152). With D-glucopyranosides, the primary (but not a secondary) sulfonyloxy group is so replaced; thus, methyl 2,3,4,6-tetra0-mesyl-a-D-glucoside treatedz4 with potassium acetate, in boiling acetic anhydride under reflux during one hour, affords an almost quantiSimitative yield of methyl 6-0-acetyl-2,3,4-tri-0-mesy~-a-~-glucoside. larly, 3-(tetra-0-acetyl-~-~-glucopyranosyl)-5-0-acetyl-l,2-0-isopropylidene-6-0-mesyl-(or -6-O-tosyl-) D-glucose giveszb2 the 5,6-diacetate, and 5-(tetra-O-acetyl-~-~-glucopyranosyl)-3-O-acetyl-l,2-O-isopropylidene-6-0-mesyl-(or -6-0-tOSyl-)D-glUCOSe giveszb2the corresponding 3,6diacetate. As already mentioned, this reagent in acetic anhydride does not effect replacement of " ring" secondary sulf onyloxy groups of cyclic-sugar derivatives. Attempts to accomplish replacement of the tosyloxy group of 1,2:5,6-di-0-isopropylidene-3-O-tosyl-~-glucose under a variety of conditions224were fruitless. However, there is no reason t o believe that replacement of secondary sulfonyloxy groups cannot be effected with acyclic-sugar derivatives and acyclic alditol derivatives of the types previously discussed. A rather obvious extension of these uses of potassium acetate consisted in employing, in its stead, potassium thiotacetate (KSAc). In 1950, Chapman and Owen36found that the effects of this reagent are strictly analogous to those of potassium acetate. Thus, 1,2:5,6-di-O-isopropylidene-3-0-tosyl-~-glucoseis unchanged by the reagent (in acetone) during 18 hours at 110" (sealed tube). On the other hand, the simplest compound having two primary tosyloxy groups, namely, 1,Bditosyloxyethane (which is highly reactiveS64towards sodium iodide-acetone; see compound 1, Table IV), gives an 83% yield of potassium p-toluenesulwith fonate plus a 59% yield of l12-bisacetylthioethane on refl~xing4~8 100% excess of potassium thiolacetate in absolute ethanol for only 30 minutes. With alditol derivatives, a somewhat longer period of refluxing suffices to give excellent yields. Thus, 1,3-di-S-acetyl-1,2,3-trideoxy1,3-dithio-tri-itol was obtaineda6in 88% yield on so treating 2-deoxy1,3-di-O-tosyl-tri-itol (-'' glyceritol ") during one hour: (427) Cf.,W. Hiickel and W. Tappe, Ann., 857, 113 (1939). (428) L. N. Owen and P. N. Smith, J . Chem. Soc., 2973 (1951).
SULFONIC ESTERS OF CARBOHYDRATES
CH~SAC
CHoOTs
kHz
215
+
AHn
&Haon hH2SAc Similarly, 3-deoxy-l,2-di-O-mesyl-(or -1,2-di-0-tosyl-)~,~-glyceritol aff ordedab (in 6 to 8 hours) 1,2-di-B-acetyl- l12,3-trideoxy-1,2-dithio- D,Lglyceritol, the mesyloxy groups being less reactive than the tosyloxy gavea5 (in 8 hours) groups ; and 1-0-acety1-2,3-di-0-tosyl-~,~-glycentol l-0-acetyl-2,3-di-S-acetyl-2,3-dideoxy-2,3-dithio-~~~-glyceritol. As might be expected, l-0-benzoyl-3-deoxy-2-O-tosyl-~,~-glyceritoI was less the latter reactive than 2-0-benzoyl-3-deoxy-l-0-tosyl-~,~-glyceritol; after affordeda5 l-Sacetyl-2-0-benzoyl-1,3-dideoxy-l-thio-~,~-glyceritol refluxing an acetone solution for one hour, whereas the former required36 treatment in a sealed tube at 110' for 15 hours in order to give a 56% As yield of 2-S-acetyl-l-O-benzoyl-2,3-dideoxy-2-thio-~,~-glyceritol. regards these, and all other, replacements of a secondary sulfonyloxy group discussed here, it is still unknown whether or not a Walden inversion occurs. The behavior towards potassium thiolacetate of a few alditols bearing acetal rings has been studied. On refluxing in acetone for 6 hours, 2,3,4,5di-0-methylene-1,6-d-O-tosyl-~-mannitol gave36 an 89 % yield of the 1,6-di-S-acetyl-1,6-dideoxy-1,6-dithio derivative, but, after only 4 hours, a 100% yield of potassium p-toluenesulfonate plus the corresponding 1,6-di-S-acetyl-l,6-dideoxy-l,6-dithioderivative w a 0btained4~9from 2,5-di-0-acetyl3,4-0-isopropyliden~1,6di-O-tosyl-~-mannitol (bearing only one acetal ring). After refluxing in acetone for 6 hours, only the 6-tosyloxy group of 1,3:2,4-di-0-ethylidene-5,6-di-0-tosyl-sorbitol reacted, giving85 an 87 % yield of 6-S-acetyl-6-deoxy-l,3 :2,4-di-O-ethylidene-6thio-5-0-tosyl-sorbitol; this product was unchangedab by further treatment during 15 hours a t 110'. The 5,6-di-O-mesyl derivative was less reactive than the 5,6-di-O-tosyl derivative, and gave36no recognizable product. The sulfonylate of only one alditol bearing anhudro rings has been examined thus far. When 1,4:3,6-dianhydro-2,5di-O-mesyl-~-mannitol was treated429 with the reagent plus a small amount of thiolacetic acid in absolute ethanol (in a sealed tube during 12 hours a t 110-15') it gave a 100% yield of potassium methanesulfonate plus 2,5-di-X-acetyl-l14:3,6dianhydro-2,5-dideoxy-2,5-dithio-~-"mannitol."By acid hydrolysis (e.g., with 2.5% hydrogen chloride in methanol during 4 to 8 hours under 9 reflux, with a nitrogen atmosphere), the M A C compounds g i ~ e 3 6 1 4 ~the corresponding thiols, RSH. (429)
P. Bladon and L. N. Owen, J . Chem. Soc., 585 (1950).
This Page intentionally left blank
THE METHYL ETHERS OF D-MANNOSE BY G . 0. ASPINALL The University of Edinburgh, Scotland
CONTENTS I. Introduction. . . . . . . . . .................... 11. Monornethyl-~-m~nnos . . . . . . . . . . . . . . . . . . . . . 1. %Methyl-D-mannose... . . . . . . . . . 2. &Methyl-D-mennose.. ... 3. 6-Methyl-~-mannose....................... 4. Characterization of Monomethyl-D-mannoses 111. Dimethyl-D-mannoses. . . . . . . . . . . . . . . . . . 1. 2,3-Dimethyl-~-mannose.. . . . . 2. 3,4Dimethyl-~-mannose.. . . . . 3. 4,6-Dimethyl-~-mannose.. . . . . . . . . . . . . . . . . . 4. 5,6-Dimethyl-~-msnnose. . 5. Characterization of Dimethyl-D-mannosee. . . . IV. Trimethyl-D-mannoses., . . . . . . . . 1. 2,3,4-Trimethyl-~-mannose. ............... 2. 2,3,6-Trimethyl-~-mannose 3. 2,3,6-Tri~nethyl-n-mannose 4. 2,4,6-Trimethyl-~-msnnose. .... 5. 3,4,6-Ti-imethyl-~-msnnose 6. Characterization of Trimet V. Tetramethyl-o-mannoses.. . . . . . . . . . . 1. 2,3,4,6-Tetramethyl-~-mannose. ............ 2. 2,3,5,6-Tetramethyl-~-mannose. ............ 3. Characterization of Tetramethyl-D-mannoses.
........ ..............
219 220 220
. . . . . . . . . . . . . . . . . . 224
......... ...........
225 226 228 228
I. INTRODUCTION The importance of the methyl ethers of D-mannose lies largely in their occurrence in structural studies in the polysaccharide field. Since previous articles in this series'JJ have discussed the basic principles involved in the preparation and elucidation of the structure of partially methylated aldoses, it is not intended to give unnecessary details in cases where general procedures are already familiar. In every case so far investigated, D-mannose has been found to occur (1) E. J. Bourne and S. Peat, Advances in Carbohydrate Chem., 6 , 145 (1950). (2) D. J. Bell, Advances in Carbohydrate Chem., 6, 11 (1951).
(3) R. A. Laidlaw and E. G . V. Percival, Advances i n Carbokydrale Chem., 7, 1 (1952).
217
218
Q, 0. ASPINALL
naturally in the pyranose form, and apart from 2,3,5-.tnmethyl-~-mannofuranose and 2,3,5,6-tetramethyl-~-mannofuranose, no methylated derivatives containing a furanose ring have so far been synthesized. I n the preparation of partially methylated derivatives, use has been made of benzylidene, isopropylidene and trityl derivatives of D-mannose to protect respectively the 4 and 6, 2 and 3, and 6 positions.
11. MONOMETHYL-D-MANNOSES 1. &MethydD-rnannose
2-Methyl-D-mannose was first obtained crystalline by Pacsu and Trister.' Methylation of 3,4:5,6-diisopropylidene-~-mannose dibenzyl mercaptal by treatment of the sodium alkoxide with methyl iodide was followed by removal of the isopropylidene residues, giving methyl-^mannose dibenzyl mercaptal. The mercaptal group was removed in dry methanol with mercuric chloride, giving a mixture of the methyl a-D-furanoside and the dimethyl acetal. From the hydrolysis of the methyl a-D-furanoside, crystalline 2-methyl-a-D-mannose was isolated. It is probable that this sugar had been obtained before in an impure state, Pacsu and v. KaryKhaving previously methylated diisopropylidene-Dmannose dibenzyl mercaptal and having obtained a sirup which they wrongly supposed to be the 4-methyl ether. Subsequent work by Munro and PercivaP showed that Pacsu and v. Kary's product was not the 4-methyl ether, but these workers were unable to isolate either the 2-methyl ether or any of its derivatives in a pure state. Very little conclusive evidence for the position of the methyl group in %methyl-~-mannoseis available. Pacsu and Trister* showed that the sugar reacted with phenylhydraaine in the cold to give a phenylhydrazone but not a phenylosarone. More drastic conditions were required to form the phenylosazone, during which reaction the methy1 group was lost with the formation of D-glucoaazone. 2. ,$-Meth&~-mannose
The synthesis of 4-methyl-~-mannose was first achieved simultaneously, but independently, in two different ways. Haskins, Hann and Hudson7 methylated 2,3-isopropylidene-l,6-anhydro-P-~-mannopyranose with methyl iodide and silver oxide, the product on hydrolysis yielding (4)E. Paosu and 8.M. Trister, J . Am. C h . SOC.,68,926 (1941). (5) E.Paosu and Charlotte v. Kary, Ber., 82,2811 (1929). (6)J. Munro and E. G. V. Percivd, J . Chem. SOC.,640 (1936). (7) W.T. Haskins, R. M. Hann and C. S. Hudson, J . Am. Chem. Soc., 66, 70
(1943).
METHYL ETHERB OF D-MANNOSE
219
the crystalline 4-methyl-a-~-mannose. Schmidt and his coworkers8.s carried out an alternative synthesis by methylation of 2,3:5,6-diisopropylidene-D-mannonic acid with dimethyl sulfate and sodium hydroxide, followed by removal of the isopropylidene residues to give 4-methylD-mannonic acid, isolated as the b-lactone. Catalytic reduction of the lactone over platinic oxide gave a mixture of the free sugar and the corresponding hexitol, the sugar being isolated via the benzylphenylhydrazone. The sugar has also been synthesized by Smith,’O who methylated methyl 2,3-isopropylidene-6-trityl-cr-~-mannopyranos~de, 4-methyl-~-mannosebeing obtained as a viscous syrup after methanolysis and hydrolysis. The structure of this sugar was established as follows: (a) reaction with phenylhydrazine yielded 4-methyl-~-glucosazone;I1 (b) oxidation (HOBr) yieIded a methylmannonolactone, which exhibited the properties that are characteristic of 6-lactones.’ 3. 6-Methyl-~-mannose Watters, Hockett and HudsonI2 have prepared a non-crystalline monomethylmannose which forms an osazone with the same properties as those of 6-methyl-~-g~ucosazone. The synthesis was achieved by followed methylation of methyl 2,3,4-triacetyl-a-~-mannopyranoside, by hydrolysis. Schmidt and Heiss, studying the epimerization of 6-methyl-~-gluconic acid, have claimed to have isolated the phenylhydrazide of 6-methyl-~-mannonicacid. 4. Characterization of Monomethyl-D-mannoses Table I records appropriate data and references relating to the monomethyl-D-mannoses and their more important derivatives. (8) 0. T. Schmidt, Catharina C. Weber-Molster and Helen Hauss, Ber., 76, 339 (1943). (9) 0.T.Schmidt and Hertha Muller, Ber., 76, 344 (1943). (10) F. Smith, J . Chem. SOC.,2652 (1951). (11) A. E. Knauf, R. M. Hann and C. S. Hudson, J . Am. Chem. Soc., 63, 1447 (1941). (12) A. J. Watters, R. C. Hockett and C. S. Hudson, J . Am. Chem. Soc., 61,1528 (1939). (13) 0.T.Schmidt and H. Heiss, Ber., 82, 7 (1949).
G. 0. ASPINALL
220
TABLEI Monomethyl-D-mannoses and S o m of Their Characteristic Derivatives
Compound %-Methyl-u-~-mannose phenylhydrazone dimethyl acetal methyl a-D-furanoside 4-Methyl-a-~-mannose
136-137 163 111-112 82 127-128 129-130 158 157-158 128-130 75-76 63-64 101- 103 101-102
phenylosazone benzylphenylhydrazone a-tetraacetate (?)@-tetraacetate methyl a-D-pyranoside 4-Methyl-~-mannonicacid sodium salt &-lactone phenylhydraside amide 6-Methyl-wmannose phenylosasone 6-Methyl-~-mannonicacid phenylhydrazide
-
Rotation Refersolvent ences
Melting ooint, "C.
4 4 4 4 7 9 9 7 9 7 7 9 7
172
+7.0-, +4.5 - 4 9 . 1 4 -60.7 -11.3 +129.5 f 3 4 . 0 4 +22.6 +32.4( f 0 . 5 ) 3 +22.3 -32.3( f 2 . 5 ) 3 0 -36+ -14.4 +49.2(f0.6) + +46.9 +59.2 $20.2 +84.9( f0.9) +83.9 +24(f0.4) +2( f0.4) +162.3+ +94.3 +163.8+ +94.2 10 $10.6 f11.7 +11.9 +15.3 - 6 8 . 6 4 -48.0
8 7 8 7 8 7 12 12
178
+3.5 ( k 0.7)
13
-
164-165 165-166 147-148 146-147 176 171-172
-
+
8 8
111. DIMETHYL-D-MANNOSES 1. 2,3-Dimethyl-D-mannose 2,3-Dimethyl-o-mannose has been isolated from the hydrolysis products of the methylated galactomannans from carob seed gurnl4J6 and from guar gumJl6J7and also from mannocrtroloseJ18J9a polysaccharide synthesized by Penicillium chrlesii G . Smith. The synthesis of this sugar, which has not been obtained crystalline, has been accom(14) (15) (16) (17) (18) (19)
E. L. Hirst and J. K. N. Jones, J . Chem. Soc., 1278 (1948). F. Smith, J. Am. Chem. SOC.,70, 3249 (1948). 2.F. Ahmed and R. L. Whistler, J . Am. C h . Soc., 72, 2524 (1950). C. M. Rtlfique and F. Smith, J . Am. Chem. SOC.,72, 4634 (1950). W. N. Haworth, H. Raistrick and M. Stacey, Biochem. J . , 29, 612 (1935). M. Stacey, J . Chem. SOC.,857 (1947).
METHYL ETHERS OF D-MANNOSE
22 1
plished by Robertson.zo Methyl 4,6-benzylidene-cu-~-mannopyranoside was methylated with methyl iodide and silver oxide, the benzylidene residue removed with hot aqueous acetonic hydrogen chloride and the glycoside hydrolyzed to yield sirupy 2,3-dirnethyl-~-mannose. The constitution of the sugar rests upon the following evidence: (a) reaction with phenylhydrazine eliminated a methyl group with the formation of 3-methyl-~-glucosazone;~~ (b) oxidation of the derived 1actone2' and of the methyl glycoside'' with nitric acid gave rise t o erythro-dimethoxysuccinic acid; (c) periodate oxidation consumed 2 moles of periodate per mole of dimethyl sugar with the production of both formic acid and formaldehyde. 2. 3,4-Dimethyl-~-mannose Although this sugar has not yet been synthesized] it has been isolated from the products of methylation and hydrolysis of yeast mannan,22,2a the galactomannan from Lucerne seed,23and the specific somaticz6and lipoid-boundZ6 polysaccharides from M . tuberculosis (Human Strain). The constitution of 3,4-dimethyl-~mannosewas established by Haworth, Hirst and Isherwood.22 The presence of a methyl group in position 4 was indicated since no furanoside formation took place with cold methanolic hydrogen chloride, and oxidation (HOBr) yielded a crystalline dimethyl-D-mannonolactone, which from its rate of hydrolysis was shown to belong to the &series. 4,6-Dimethyl-~-mannosebeing already known, the choice between the 2,4- and 3,4-dimethyl sugars was easily made as the sugar formed an osazone without loss of a methyl group, and the amide derived from the dimethylmannonolactone gave a strong positive Weerman test. Later workz7 showed that periodate oxidation gave a definite though not quantitative yield of formaldehyde, thus confirming the absence of a methyl group in position 6. 3. 4,6-Dimethyl-~-mannose This sugar has been synthesized by Ault, Haworth and Hirst.zs Methyl 2,3-isopropylidene-a-~-mannopyranoside was methylated with (20) G. J. Robertson, J . Chem. Soc., 330 (1934). (21) E. H. Goodyear and W. N. Haworth, J . Chem. SOC.,3136 (1927). (22) W. N. Haworth, E. L. Hirst and F. A. Isherwood, J . Chem. Soc., 784 (1937). (23) W. N. Haworth, R. L. Heath and S. Peat, J . Chem. Soc., 833 (1941). (24) E. L. Hirst, J. K. N. Jones and Winifred 0. Walder, J . Chem. Soc., 1443 (1947). (25) (26) (27) (28)
W. N. Haworth, P. W. Kent and M. Stacey, J . Chem. Soc., 1211 (1948). W. N. Haworth, P. W. Kent and M. Stacey, J . Chem. SOC.,1222 (1948). D. J. Bell, J . Chem. L~oc., 992 (1948). R. G. Ault, W. N. Haworth and E. L. Hirst, J . Chem. Soc., 1012 (1935).
222
Q. 0. ASPINALL
methyl iodide and silver oxide, and the isopropylidene residue removed by mild acid hydrolysis t o give methyl 4,6-dimethyl-a-~-mannopyranoside, which on more vigorous hydrolysis yielded 4,6-dimethyl-~-mannose as a glass. The constitution of the sugar was established as follows: (a) oxidation (HOBr) gave a dimethylmannonolactone which behaved exclusively as a b-lactone; (b) the derived dimethylmannonamide gave a positive Weerman test indicating a free hydroxyl in position 2; (c) oxidation of methyl 2,3-isopropylidene-a-~-mannoside,~~ followed by elimination of the isopropylidene residue, gave methyl a-D-mannuronoside, indicating a free hydroxyl group in position 6 in the starting material and hence a methyl group after methylation. 4. 6,6-Dimethyl-~-mannose
Although 5,6-dimethyl-~-mannose itself is unknown, some of its derivatives have been prepared. Irvine and Patterson3" prepared a dimethylmannitol by the methylation of 1,2:3,4-diisopropylidene-~mannitol followed by hydrolysis of the isopropylidene residues with aqueous ethanolic hydrogen chloride. Nitric acid oxidation of the dimethylmannitol gave a dimethylmannonolactone with behavior characteristic of a y-lactone. The structure of the diisopropylidenemannitol, however, was not proved until Wiggins*' obtained a strongly reducing diisopropylidene-aldehydo-D-arabinoseon oxidation with lead tetraacetate, showing the isopropylidene residues to be attached at positions 1, 2, 3, and 4. 5 . Characterization of Dimethyl-wmannoses Table I1 records appropriate data and references relating to the dimethyl-D-mannoses and their more important derivatives.
R. G. Ault, W. N. Haworth and E.L. Hirst, J . C h m . Soc., 517 (1935). (30) J. C. Irvine and Bina M. Patterson, J . Chem. Soc., 106,898 (1914). (31) L. F. Wiggins, J . Chem. SOC.,13 (1946). (29)
METHYL ETHERS O F D-MANNOSE
223
T~LBLE II Dimethyl-D-mannoses and Bome of Their Characteristic Derivatives Compound 2,3-Dimethyl-~-mannose
oxime methyl a-D-pyranoside 2,3-Dimethyl-~-mannonic acid 7-lactone
Melting poia, "C liquid
112-114 liquid -
109-11( 107 111
phenylhydraaide
1,2-isopropylidenemethyl a-D-pyranoside 3,4Dimethyl-~-mannonioacid &lactone
156 107-109 114 94 87 -
L57-158 L59-160
amide 4,6-Dimethyl-~-mannose 2,3-hpropylidene-a-~-pyranose methyl a-D-pyranoside 4,6-Dimsthyl-~-mannonicacid &lactone
140 141
dw
76-77
liquid -
55
amide
119
phenylhydraeide
151
5,8Dimethyl-~-rnannonicacid y-lactone
+6.0 +10.6 -4.3 -15.8
12-114
-
-
+43.5 -31.0+ 0 (incomplete) +61.1+ +60.5 (incomplete) +60+ +57 (incomplete) +81.5+ 4-52.5 (incomplete) +64.5 + +35 (incomplete)
-
170 L 58(168:
3,CDimethyl-D-mannose a-monohydrate
[alD,
-25 -24.2 +3 (equil.) +30.0 +22+ +4 - 17 $67 107 +32 +174--+ +129 (50 hr., equil.) +178+ +131 (120 hr., equil.) $22 $25.7 +25 +I1 0-4 -9.5 (6 hr., equil.) +80.5 +99 +20+ +68 (150 hr., equil.) +165+ +70 (150 hr., equil.) 145 -3 +15 -3.5 14
+
+
+
+22.4+ 4-16.2 (6 days, equil.)
E&F ewes __ 20 20 20 20 20 20 15
21 14 15 17 14 15 17 22 23 23 23 23 23 22 22 23 22 23 28 28 28 28 28 28 28 28 28 28 28
28
30
-
224
Q. 0 . ASPINALL
IV. TRIMETHYGD-MANNOSES 1. dl3,Q-Trirnethyl-~-mannose
The first synthesis of this sugar, which is known only as a sirup, was achieved by Haworth, Hirst, Isherwood and Jones82by the methylation of methyl 6-trityl-a-~-mannopyranoside. The methyl 6-trityl-2,3,4trimethyl-a-D-mannoside thus obtained was treated with hot glacial acetic acid to remove the trityl residue, and the resulting glycoside gave on hydrolysis 2,3,4-trimethyl-~-mannose. The sugar has also been synthesized by the methylation of 1,6-anhydro-~-~-rnannopyranose~~ with dimethyl sulfate and alkali, followed by hydrolytic cleavage of the has been anhydro ring with dilute acid. 2,3,4-Trimethyl-~-mannose shown to be present amongst the hydrolysis products of methylated yeast mannanJZ8having been isolated as the derived &-lactone. The crystalline trimethylmannose isolated from the hydrolysis of methylated mannocaroloseJ1*and described as the 2,3,4-compound, differed markedly in its properties from the synthetic compound and was obviously a different isomer. Recent work,Ig however, has shown that 2,3,4-trimethyl-~mannose and the crystalline 3,4,6-isomer occur together in equimolecular proportions in the hydrolyxate of methylated mannocarolose. The constitution of the sugar follows from the methods employed in its synthesis. Confirmation wm obtained by the following observations : (a) permanganate oxidation of the methyl a-D-glycopyranoside yielded 2,3,4-trimethyl-~-mcronicacida4 on hydrolysis of the resulting glycoside; (b) oxidation (HOBr) gave a characteristic 6-lact0ne.~~ 2. d , S , 6 - T r ~ m e t h y l - ~ - m o s e This sugar was prepared by Heslop and Smitha6by methylation of methyl 6-trityl-a-~-mannofuranosidewith methyl iodide and silver oxide, followed by removal of the trityl residue with ethereal hydrogen chloride as a and hydrolysis of the glycoside to yield 2,3,5-trimethyl-~-mannose sirup. The constitution of the sugar follows largely from the method of synthesis. Confirmation was obtained by the following observations: (a) oxidation (HOBr) yielded a lactone with properties characteristic of y-lactones; (b) further oxidation gave a trimethylmannosaccharic acid, whose diamide gave a negative Weerman test. (32) W. N. Haworth, E. L. Hirst, F. A. Isherwood and J. K. N. Jones, J . Chern.
Soc., 1878 (1939).
(33) G. Zemplh, A, GereEs and Theodora Valatin, Ber., 73, 575 (1940). (34) F. Smith, M. Stacey and P. I. Wilson, J . Chern. Soc., 131 (1944). (35) (Miss) D.Heslop and F.Smith, J . Chem. Soc., 574 (1944).
METHYL ETHERS OF D-MANNOSE
225
3. 2,S16-Trimethyl-~-mannose Although this sugar has not been prepared synthetically, it is a constituent of the hydrolysis products of methylated polysaccharides containing mannose units linked 1 to 4, for example, the mannans from ivory n ~ t , ~~ a ~l e -p and ,~~ ~~ the seaweed Porphgra umbili~alis,~''and from the galactomannans from ~ a r ' o band ~ ~ gt ~~ a~r ' ~ seeds. ~'' The structure of the sugar follows from the work of Haworth, Hirst and Streighk4I Methylation with methyl iodide and silver oxide gave a mixture of methyl 2,3,4,6tetramethyl-D-mannopyranosides from which the methyl 0-D-glycoside was obtained crystalline and from the hydrolysis of which the 2,3,4,6tetramet hyl-D-mannose was characterized as the anilide. The presence of a second free hydroxyl group, in position 4, was shown by oxidation (HOBr) of the free sugar to a y-lactone which on methylation gave 2,3,5,6-t etramethyl-D-mannonolactone.
4. S,4,6'- Trimethyl-~-mannose This sugar was isolated as its monohydrate from the hydrolysis products of methylated yeast mannan and its structure proved by Haworth, Heath and Peat.23 Methylation of the methyl glycoside gave the crystalline methyl 2,3,4,6-te trame t hyl-a-D-mannopyranoside, indicating a pyranose structure. It seemed likely that the compound was the monohydrate of 2,4,6-trimethyl-~-mannose,as the 2,3,4- and 2,3,6-isomers were known as sirups that did not form hydrates, and the crystalline 3,4,6-isomer could not be converted into a hydrate; furthermore, the derived anilide was different from those of the 2,3,6- and 3,4,6-trimethylD-mannoses. Oxidation (HOBr) gave a 6-lactone that is different from the isomeric 2,3,4- and 3,4,6-trimethyl-~-mannonolactones, and the derived amide gave a negative Weerman test, confirming the presence of a methyl group in position 2. 5 . S,~,G-Trirnethyl-~-mannose
3,4,6-Trimethyl-~-mannose was first synthesized by Bott, Haworth and H i r ~ tduring , ~ ~ their study of the obstructed form of methyl Z-acetyla-D-mannoside, methylation of which compound, followed by acid J. Patterson, J . Chem. SOC.,123, 1139 (1923). F. Klages, Ann., 609, 159 (1934). F. Klages, Ann., 612, 185 (1934). F. Klages and R. Niemann, Ann., 623, 224 (1936). (40) J. K. N. Jones, J . Chem. Soc., 3292 (1950). (41) W. N. Haworth, E. L. Hirst and H. R. L. Streight, J . Chern. Soc., 1349 (1!131). (42) H. G. Bott, W. N. Haworth and E. L. Hirst, J . Chem. SOC.,1395 (1930).
(36) (37) (38) (39)
226
G . 0. ASPINALL
hydrolysis, yielded the sugar in its crystalline a-pyranose form. The sugar has also been derived from the hydrolysis of methylated polysaccharides, notably from yeast mannan,2a the carbohydrate residue in o ~ o m u c o i d and , ~ ~ the specific somatic polysaccharide from M . tubercuand also from the methylation and hydrolysis of the aldobiouronic acid obtained from damson44and cherry The constitution of this sugar was established as follows: (a) oxidation (HOBr) gave a &lactone having the same melting point and the same magnitude of rotation, but of opposite sign, as 3,4,6-trimethyl-~-mannonolactone synthesized by Haworth and Peat46from 2,3,5-trimethyl-~arabofuranose; (b) further methylati0n4~ yielded the known methyl 2,3,4,6-tetramethyl-&~-mannopyranoside,thus confirming the presence of a pyranose ring; (c) treatment of the 8-lactone with liquid ammonia produced an amide44 giving a positive Weerman test, thus showing the presence of a free hydroxyl in position 2. 6. Characterization of Trimethyl-D-mannoses Table 111 records appropriate data and references relating to the trimethy1-D-mannoses and their more important derivatives. (43) (44) (45) (46)
M. Stacey and J. M. Woolley, J . Chem. SOC.,550 (1942).
E.L. Hirst and J. K. N. Jones, J . Chem. Soc., 1174 (1938).
J. K. N. Jones, J . Chem. SOC.,558 (1939). W.N. Haworth and S . Peat, J . Chem. SOC.,350 (1929).
227
METHYL ETHERS OF D-MANNOSE
TABLEI11 TrimelhybD-mannoses and Some of Their Characteristic Derivatives Compomd
2,3,4Trimethyl-~-mannose
1,6-anhydro methyl or-D-pyranoside 2,3,4-Trimethyl-~-mannonic acid &lactone monohydrate
Melting point, "C. liquid 52
liquid 73 74 72-73
amido phenylhydrazide 2,3,5-Trimethyl-~-mannonic acid sodium salt 7-lactone amide 2,3,6-Trimethyl-~-mannose anilide
2,3,6-Trimethyl-~-mannonic acid 7-lactone
143 166 -
118 162
liquid 127-128 133 131
89
Rotation solvent
References
-
+2 -5 -70.7 -65.5 +47
32 33 33 33 34
+138-+ +81 (95 hr., equil.) i-131-t +80 (170 hr., equil.) 4-129.5- +78.4 (72 hr., equil.) +5
32
-31 - 27 $67 4 +63.5 (22 days, incomplete) -28 +6 - 10
-155+
-39
-19.54-39 (23 days) +73+67
34 33 32, 34
40 35 35 35 35 47 14 41, 47 14 15 15 41
(6 days, incomplete) 84-85
amide phenylhydrazide (anhydrouE phenylhydrazide hydrate 2,4,6-Trimethyl-~-mannose a-pyranose monohydrate 8-pyranose anilide
+ 6 5 . 5 - + +38.5 (120 days)
15 14 15, 16
130 125 144 133
-21 -16.5 -21
17
90
+21+
23
104-107 134
+14 (2 hr.) - 5 . 7 - t +19.0 -150.+ +8 (13 hr.)
15, 17
23 23
-
G . 0. ASPINALL
TABLE I11 (Continued) Melting point, "C.
Compound
2,4,6-Trimethyl-~-mannonic acid S-lactone
97-98
amide 145 3,4,6-Trimethyl-a-o-mannose 101-102
104 140-143
anilide
3,4,6-Trirnethyl-n-mannonic acid &lactone phenylh y drazide amide
98-97
99-100 137-139 141 143
Rotation solvent
+141+ $30 (103 hr. a t 30")
+7.0
+36 f21-3 +8.2 f154.5+ -55.5 (24hr.) +31+ +111 +167.5-+ +I10 (74hr., equil.) +168+ +ll6 +25 f28
References
23 23 42 42 43 23 42 42 44 42 44 23
V. TETRAMETHYL-D-MANNOSES 1. d13,.4,6-Tetramethyl-~-mannose
This sugar was first prepared by Irvine and M o ~ d i by e ~the ~ methylation of methyl a-D-mannopyranoside with methyl iodide and silver oxide in the presence of methanol as solvent. The crystalline methyl tetramethyl-a-D-mannoside yielded, on acid hydrolysis, sirupy Z13,4,6-tetramethyl-D-mannose. Methylation has been carried out subsequently ~ ~ *by~ ~ the reaction of using dimethyl sulfate and sodium h y d r o ~ i d e and the potassium salt of methyl a-n-mannopyranoside with methyl iodide in liquid ammonia.61 The Haworth methylation procedure has also been (47) W.N.Haworth, E. I,. IIirst and Millicent M. T. Plant, J . Chem. SOC.,1354 (1931). (48)J. C. Irvine and Agnes M. Moodie, J. Chem. Soc., 87, 1462 (1905). (49) W.N.Haworth, J . C h e w Soc., 107,8 (1915). (50) H.D. K.Drew, E. H. Goodyear and W. N. Haworth, J . Chem. Sac., 130, 1237 (1927). (51) I. E.Muskat, J . Am. Chem. Soc., 66, 693 (1934).
METHYL E T H E R S O F D-MANNOSE
229
extended to the P-D-series.K2 The sugar was first obtained crystalline by Greene and L e w k s 3 2,3,4,6-Tetramethyl-~-mannose has been obtained from the hydrolysis products of a number of methylated polysaccharides, for example the mannans from ivory n ~ t , s~a l~e ~e , 3~ yeast22*23 ~~ and from the seaweed Porphyra ~rnbilicalis.4~The structure of the sugar was confirmed by the following observations: (a) oxidation (HOBr) gave a lactone th a t mutarotated as a S-lactone:6° (b) further oxidation with nitric acid yielded D-arabo-trimethoxyglutaric acid, identified as the crystalline methylamide. 2 1 2 . 2,3,6,6-Tetramethyl-~-rnannose
2,3,5,6-Tetramethyl-~-mannose was first prepared by Irvine and Burts4 by the methylation of methyl " y "-~-maiinoside (now known t o be a mixture of the methyl a- and /3-D-mannofuranosides) with methyl iodide and silver oxide, followed by hydrolysis to the free sugar. Later work,66 however, threw doubt upon the purity of the tetramethyl-Dmannose thus obtained. Haworth, Hirst and Webb, starting with crystalline methyl a-D-mannofuranoside, carried out the methylation both with dimethyl sulfate and sodium hydroxide and with methyl iodide and silver oxide, and obtained crystalline methyl tetramethyl-aD-mannofuranoside, which was readily hydrolyzed with dilute mineral acid t o yield the sirupy 2,3,5,6-tetramethyl-~-mannose.The constitution of this sugar follows from the fact that oxidation (HOBr) gave the crystalline 2,3,5,6-tetramethyl-~-mannono1actone, K6 which had previously been prepared by the methylation of y-D-mannonolactone.67 This methylated lactone mutarotated as a y-lac%one and further oxidation with nitric acid gave only erythro-dimethoxy-succinic acid and no D-arabotrimethoxyglutaric acid. 2 1
3. Characterization of l'etramethyl-D-rnannoses Table I V records appropriate data and references relating to the tetramethyl-D-mannoses and their more important derivatives. (52) H. G. Bott, W. N. Haworth, E. L. Hirst arid R. S. Tipson, J. Chem. SOC., 2653 (1930). (53) R. D. Greene and W. L. Lewis, Science, 64, 206 (1926); J . Am. Chem. SOC., 60, 2813 (1928). (54) J. C. Irvine and W . Burt, J . Chcm. Soc., 126, 1343 (1924). (55) W . N. Haworth, E. L. Himt and J. I . Webb, J . Chem. Soc., 651 (1930). (56) 1'. A. Levexie and G. M. Meyer, J . Riol. Chem., 76, 809 (1928). (57) P. A. Levme and G. M. Meyer, J . Biol. Chem., 60, 167 (1924).
G. 0. ASPINALL
230
TABLE IV Tetramethyb-mannoses and Some of Their Characteristic Derivatives Compound
Melting point, "C. liquid 10.5-51 .!
Rotation solvent 3-1.2 +27.6 +23 .O 3.2.4
Teferences 48 53 53 53
(equil.) a-pyranose form anilide
49-50 142-143 144-145
methyl a-D-pyranoside
37-38
methyl 8-D-pyranoside
38-40 36-37
2,3,4,6-Tetramethyl-~-mannonic acid
sodium salt &lactone
24-25
3.11.5-t +2.5 -87.9+ -8.3 - 9 5 . 5 4 -38.9 - 8 4 . 0 4 -7.5 (11 hr.) -t42.9 -t70.5 +75.5 $43 -80 79 82 87 - 72
58 59 59 23
+14.8
50
48 48 48 52 52 52 52 52 52
-
(initially) 4 - 1 7 . 5 4 f42.0 (24 hr., incomplete) +41.6 f150
57 57 50
(initially) liquid 25
phenylhydrazide
184-185 186-187 183-184
liquid
methyl a-D-furanoside 24 2 3,5,6-Tetramethyl-~-mannonic acid sodium salt y-lactone 107-108 107
+136.4+ +62.8 (6 days) +150--, +67 (100 hr., equil.) -
108-109 167
22 -
-22 +47.4 +48.5 t 3 9 4 +43 +37 +99
CHCla CzH6OH CHsOH H2 0 CHsOH Hz0
-25.3+ -22.5 +64.8 +65.2+
HzO HzO Hz0 HzO
$48.2
+56.3
(incomplete) phenylhy drazide
53
50 28 46 54 54
55 55 55
57 57 56 57 41 21
(58) B. C. Hendricks and R. E. Rundle, J . Am. Chem. SOC.,60, 2563 (1938). (59) J. C. Irvine and D. McNicoll, J . Chem. Soc., 07, 1449 (1910).
THE CHEMICAL SYNTHESIS OF D-GLUCURONIC ACID
BY C. L. MEHLTRETTER Northern Regional Research Laboratory, * Peoria, Illinois CONTENTS I. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11. Reduction of 1,4-~-Glucosaccharolactonc.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111. Oxidation of D-Glucose Derivatives by Various Agents.. . . . . . . . . . . . . . . . . . 1. Potassium Permanganate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2. Nitrogen Dioxide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3. Catalytic Oxidation by Oxygen.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4. Use of Other Oxidants.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
231 233 236 236 239 242 247
I. INTRODUCTION D-Glucuronic acid in conjugate form was first detected in the urine of animals in 1874.' Five years later Schmiedeberg and Meyer2 isolated crystalline D-glucuronolactone from the glucuronoside excreted by dogs that had been fed camphor. It was not until 1891, however, th a t the first chemical synthesis of D-glucuronic acid was effected by Fischer and Pi10ty.~ I n this synthesis Fischer's method for the reduction of aldonic acid lactones by sodium amalgam to the corresponding aldoses4 was applied t o D-glucosaccharolactone. Other methods for preparing D-glucuronic acid were devised during the next forty-eight years, chiefly through the oxidation of derivatives of D-glucose by halogens, hydrogen peroxide, and potassium permanganate. In some of these reactions, only the aldehyde function of D-glucose was protected from oxidation, and in others the secondary hydroxyl groups also were blocked. Even the best of these syntheses6was tedious, however, and gave an overall yield of n-glucuronolactone from D-glucose of only twenty percent. The inadequacy from a preparative standpoint of the early methods
* One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, U. S. Department of Agriculture. (1) M. Jaff6, Ber., 7 , 1673 (1874). (2) 0. Schmiedeberg and H. Meyer, Z. physiol. Chem., 3, 422 (1879). (3) E. Fischer and 0. Piloty, Ber., 24, 522 (1891). (4) E. Fischer, Ber., 22, 2204 (1889). (5) M. Stacey, J . Chem. SOC.,1529 (1939). 23 1
232
C. L. MEHLTRETTER
for obtaining D-glucuronic acid by either chemical means6or by hydrolysis of polyuronide natural gums' fostered use of the relatively simple biological synthesis developed by Quicks and by Williams.@ These investigators were able to obtain yields of forty t o forty-five percent of D-glucuronic acid by hydrolysis of the D-glucuronosides obtained from the urine of animals that had been fed borneol or menthol. The quest for a satisfactory chemical synthesis of D-glucuronic acid was renewed with increased vigor when Petermanlo reported in 1947 that this compound showed promise in the treatment of rheumatic diseases. The search was stimulated also by the development of more efficient techniques for the preferential oxidation of primary alcohol groups to carboxyl groups in carbohydrates. Dalmer and Heyns" in 1940 had selectively oxidized the more active primary hydroxyl group of L-sorbose with oxygen in the presence of platinized carbon catalyst, thereby obtaining 2-keto-~-gulonicacid, the precursor of L-ascorbic acid. Shortly thereafter, the use of nitrogen dioxide for the oxidative preparation of uronic acid derivatives from carbohydrates having the aldehyde function protected through a glycosidic linkage was discovered independently by Maurer12 and by Kenyon,lS with their respective coworkers. Application of the catalytic oxidation procedure of Dalmer and by Mehltretter, AlexHeynsll to 1,2-isopropy~idene-~-~-g~ucofuranose ander, Mellies and Ristl4 has resulted in the preparation of 1,2430propylidene-D-ghcuronic acid in a t least fifty percent yield. Mild hydrolysis of the latter substance eliminated acetone and produced D-glucuronic acid nearly quantitatively. This convenient method for preparing D-glucuronic acid possesses the advantages of simplicity and high yield of product. The procedure should be useful also for synthesizing other uronic acids from appropriately substituted monosaccharides. I n the present chapter, the more significant methods which have been reported for the chemical synthesis of D-glucuronic acid will be described and discussed. They are reductive and oxidative procedures and will be (6) (a) M. Stacey, Aduances in Carbohydrate Chem., 2, 161 (1946);(b) J. W. Green, ibid., 8, 164 (1948). (7) F. Weinmann, Ber., 62, 1637 (1929);J. K. N. Jones and F. Smith, Advances i n Carbohydrale Chem., 4,243 (1949);E.Anderson and Lila Sands, ibid., 1,329 (1945). (8) A. J. Quick, J . BioE. Chem., 74, 331 (1927). (9) R.T.Williams, Nature, 143, 641 (1929). (10) E. A. Peterman, Journal-Lancet (Minneapolis Medical Society), 67, 45 1 (1 947). (11) 0.Dalmer and K. Heyns, U. S. Pat. 2,189,778and 2,190,377 (1940). (12) K.Maurer and G. Drefahl, Ber., 76, 1489 (1942). (13) E.C. Yackel and W. 0. Kenyon, U. S. Pat. 2,232,990(1941). (14) C. L. Mehltretter, B. H. Alexander, R. L. Mellies and C. E. Rist, J. Am. Chem. Soc., 78, 2424 (1951);C.L. Mehltretter, U. S. Pat. 2,659,652(1951).
CHEMICAL SYNTHESIS O F D-GLUCURONIC ACID
233
reviewed in that order. No attempt will be made t o elucidate the chemistry of o-glucuronic acid, since the subject has been adequately treated elsewhere.6(a).16 11. REDUCTION OF
1,4-D-GLTJCOSACCHAROLACTONE
Sodium amalgam has been extremely useful in the synthesis and determination of structure of carbohydrates. KilianilB utilized its reducing action, resulting from liberation of nascent hydrogen from water, to convert the double lactone of a sugar acid to a polyhydric alcohol. Unfortunately, he overlooked the application of sodium amalgam to the partial reduction of the lactone of a sugar acid to form the intermediate aldose. It remained for Fischer4 to discover this synthesis and its utility, in combination with the cyanohydrin reaction, l7 for lengthening the sugar chain. In an extension of this work, Fischer and Piloty3found in 1891 that a monolactone of D-glucosaccharic acid could be reduced to D-glucuronic acid by sodium amalgam. Although the reducing power of the sirup obtained after reduction showed that approximately twenty percent of the D-glucosaccharolactone presumably had been converted t o D-glucuronic acid (11),only a small quantity of crystalline D-glucuronolactone (111) was isolated. The fact that D-glucuronolactone was obtained, however, proved that at least a part of the D-glucosaccharolactones had the 1,4-lactone structure (I). Using an analogous procedure, Kilianil9
ocHbOH
b
HO H
c:
H 0-
CHO
H 0
HCloH
HAOH
+HO H
HObH
I
I
HCOH HAOH
HAOH
I
1
COOH
COOH
I
CHSOH
T I1
111
IV
was able t o obtain a thirty percent reduction of D-glucosaccharolactone but he could not crystallize the product, which again was presumed to be (15) N. E. Artz, and Elizabeth M. Osman, “Biochemistry of Glucuronio Acid,” Academic Press, Inc., New York, 1950. (16) H. Kiliani, Ber., 20, 2714 (1887). (17) Reviewed by C. S. Hudson, Adva?aces in Carbohydrate Chem., 1, 1 (1945). (18) 0. Sohst and B. Tollens, Ann., 246, I (1888). (19) H. Kiliani, Ber., 68, 2344 (1925).
234
C. L. MEHLTRETTER
D-glucuronic acid. Recently Serchi and ArcangeliZ0reported an eightyeight percent reduction t o sirupy glucuronic acid from which D-glucuronolactone was claimed to have been crystallized in nearly quantitative yield. An explanation for the difficulty experienced in obtaining D-glucuronic acid by reduction of D-ghcosaccharolactone was provided by a detailed investigation of the structure of Sohst and Tollens’ D-glucosaccharolactone, first by Rehorst and ScholzZ1and later by Schmidt and his coworkers.22 Their results indicated a 3,6-lactone (V) configuration for the substance. This was substantiated by Sutter and ReichsteinZ3 through reduction of the saccharolactone supplied by Schmidt. Halfreduction with sodium amalgam yielded appreciable amounts of L-guluronic acid (VI), isolated as the phenylhydrazide of the phenylhydrazone. Further reduction gave a good yield of D-gluconic acid (VII) which was characterized as the phenylhydrazide. It was considered significant that L-gulonic acid (IV), the final reduction product of 1,4-~-glucosaccharolactone (I), wa8 not found. Sodium amalgam half-reduction
gHjHoH COOH
HAOH
I
COOH
HAOH
A
COOH
HAOH
c:
HCOH I - t HHLOH oH HCOH I
bHO
v
VI
HLOH
LH,OH VII
of authentic l14-lactone (I)24 by the same investigators2a produced crystalline D-glucuronic acid in forty-one percent yield. Smithz6subsequently attempted t o show that the saccharolactone of Sohst and Tollens was a mixture of 1,4- (I) and 3,6-~-glucosaccharolactone (V). Prolonged treatment of the saccharolactone with methyl iodide and silver oxide had given the tetramethyl derivatives of I and V. The interpretation of this result was criticized by ReichsteinZ6who was of the opinion that a partial isomerization of the 3,6-lactone to 1,4-lactone had occurred during the methylation procedure. I n a succeeding report, (20) G. Serchi and L. Arcangeli, Sperimentale Sez. chim. biol., 2, 108 (1951). (21) K. Rehorst and H. Schola, Be?., 69, 520 (1936). (22) 0. T. Schmidt, H. Zeisser and H. Dippold, Ber., 70, 2402 (1937); 0. T. Schmidt and P. Giinthert, Ber., 71, 493 (1938). (23) M. Sutter and T. Reichstein, Helv. Chim. Acta, 21, 1210 (1938). (24) T. Reichstein, A. Grussner and R. Oppenauer, Helv. Chim. Acta, 16, 1019 (1933). (25) F. Smith, J . Chem. Soc., 571 (1944). (26) T. Reichstein, J . Chem. Soc., 320 (1945).
CHEMICAL SYNTHESIS O F D-QLUCURONIC ACID
235
however, Smithz7 confirmed his original view by separating the two lactones from the saccharolactone preparation, by acetone extraction, and identifying them. His pure 3,B-lactone melted a t 149" as compared with 130-132" observed by Rehorst and Scholz21and 135" reported by Sutter and ReichsteinZ3for Schmidt'szz compound. The 1,blactone monohydrate which he obtained melted at 98" (sintering a t 85") while Reichstein's product melted a t about 85". It would appear from the melting points alone that the D-glucosaccharolactones prepared by Rehorst2' and by Schmidtzz were mixtures. Similar preparations by Mehltretter and Rankin,28which were composed predominantly of 3,6-lactone1 also contained small quantities of 1,4-lactone, which was isolated by extraction with acetone. The recent discovery that aldonic acid lactones may be reduced to aldoses by electrolysis a t a mercury cathodezQrepresents a n improvement over the sodium amalgam method and merits trial in the reduction of 1,4-~-glucosaccharo~actone t o D-glucuronic acid. The electrolytic process was developed t o avoid the hazards associated with the handling of large quantities of sodium amalgam, in connection with the chemical synthesis of riboflavin. Its efficiency was demonstrated by the reduction of ~-ribonolactonelZ9in aqueous solution with sodium sulfate and boric acid, to D-ribose in fifty percent yield. In this case, the sugar was isolated as the crystalline p-bromophenylhydrazone. An alternative method for recovering the D-ribose was reported by Berger and Lee130who treated the catholyte mixture with aniline (or 3,4-dimethylaniline) to obtain an insoluble complex of sodium sulfate with the arylamine D-pentoside that was formed. The isolated aniline D-ribopyranoside, on boiling with dilute acetic acid, decomposed to D-ribose and aniline, the latter of which was removed by steam distillation or extraction of its benzal derivative. Analogously, i t should be possible t o separate D-glucuronic acid from an electrolysis mixture as the insoluble sodium salt of aniline D-glucuronoside. Such a method has been successfully employed t o recover D-glucuronic acid from acid hydrolyzates of ~-glucuronosides.3 1 In the final analysis, however, an efficient synthesis of D-glucuronic acid from 1,4-~-glucosaccharolactone is dependent upon a satisfactory procedure for obtaining the latter compound. Although Reichstein and (27) F. Smith, J. Chem. SOC.,633 (1944). (28) C. L. Mehltretter and J. C. Rankin, unpublished work. (29) (a) 1%.Spiegelberg, U. S. Pat. 2,457,933 (1049); (b) T. Sato, J . Chem. SOC. Japan, 71, 194 (1950); Chem. Abstracts, 46, 9483 (1951). (30) L. Berger and J. Lee, J . Org. Chem., 11, 84 (1946); R. W. Jeanloz and H. G . Fletcher, Jr., Advances in Carbohydrate Chem., 6 , 135 (1951). (31) M. Bergmann and W. Wolff, Ber., 66, 1060 (1923); C. L. Mehltretter, U. S. Pat. 2,562,200 (1951).
236
C. L. MEHLTRETTER
his coworkersz4stated that the desired lactone can readily be crystallized by appropriate seeding of supersaturated solutions of D-glucosaccharic acid, Mehltretter and RankinZ8obtained only a mixture consisting of the isomeric lactones when authentic seed crystals of 1,4-D-glUCOSaCcharolactone were used. A contributing factor to this phenomenon, no doubt, was contamination from the atmosphere of the laboratory with 3,6-~-glucosaccharolactone in microcrystalline form. This lactone is more rapidly crystallized a t room temperature than its l14-isomer.
111. OXIDATIONOF D-GLUCOSEDERIVATIVES BY VARIOUSAGENTS 1. Potassium Permanganate
The preparation of D-glucuronic acid from D-glucose by oxidation requires t ha t the reaction be limited t o the primary hydroxyl group (on carbon atom 6). This has been accomplished both by protection of the other oxidizable groups through formation of derivatives and by the use of selective oxidants. Potassium permanganate, which has been employed for the oxidation of a number of carbohydrate derivatives, is non-specific in its action. Thus, studies with 1,2-isopropylidene-~~-~g l u c o f ~ r a n o s showed e ~ ~ th at oxidation of the secondary hydroxyl group on carbon atom 5 was accomplished readily in neutral solution, a thirty percent yield of potassium 1,2-isopropylidene-~-xyluronate being attained. An optimal synthesis of D-glucuronic acid through oxidation with potassium permanganate therefore requires that all positions in D-glucose be protected, except the primary alcohol group. The protecting groups, however, must be removed easily, since extensive degradation of D-glucuronic acid can result from too strenuous conditions of hydrolysis for their elimination. This limitation is met by isopropylidene, benzylidene, and ethylidene derivatives, which have been established as useful intermediates in the preparation of specifically substituted monosaccharides. 9 3 The lability of such cyclic acetals in acid solution necessitates, of course, that their reactions be carried out under neutral or alkaline conditions. A cyclic diacetal of this type was employed by Ohle and Berend34ca) and by Link and his c ~ w o r k e r s ~ ~in ( ~the ) , ( ~synthesis ) of D-galacturonic acid. These investigators found that 1,2 :3,4-diisopropylidene-~-galactose was converted by permanganate oxidation in alkaline solution to the (32) (a) H. Ohle, G. Coutsicos and F. Garcia y Gonzalez, Ber., 64, 2810 (1931); (b) S. Akiya and T. Watanabe, J . Pharm. SOC. Japan, 64, 37 (1944); Chem. Abstracts, 46, 5629 (1951). (33) E. J. Bourne and 5. Peat, Advances i n Carbohydrate Chem., 6, 145 (1950). (34) (a) H. Ohle and Gertrud Berend, Ber., 68, 2585 (1925); (b) C. Nieman and K. P. Link, J. BioZ. Chem., 104, 195 (1934); (c) H. M. Sell and K. P. Link, J . Am. Chem. Soc., 60, 1813 (1938).
CHEMICAL S Y N T H E S I S O F D-GLUCURONIC ACID
237
corresponding D-galacturonic acid derivative in sixty-five percent yield. Mild hydrolysis of the substituted galacturonic acid with aqueous acid and concentration t o a sirup gave crystalline D-galacturonic acid. 34(c) I n 1933, Zervas and SessleF used potassium permanganate to prepare 1,2-isopropylidene-3,5-benzylidene-~-glucuron~c acid ( I X ) in fifty percent yield from 1,2-isopropylidene-3,5-benzylidene-~-glucose (VIII). I I
HGO-
I
CHI
I
VIII
Nearly quantitative removal of the acetal groups of I X by hydrolysis with 0.1 N hydrochloric acid in fifty percent ethanol a t 100" for one hour gave D-glucuronolactone in an overall yield from D-glucose of sixteen percent of theory. Alternatively, the acetal groups could be eliminated stepwise, the yield being lowered by several percent. I n this case the benzylidene group in I X was removed with hydrogen in the presence of palladium-black catalyst. The crystalline 1,2-isopropylidene-~-glucuronic acid, which was isolated from the reaction mixture in eighty-eight percent yield, was then easily hydrolyzed with aqueous acid to D-glucuronic acid. The 1,2-isopropylidene-3,5-benzylidene-~-glucose (VIII) used by Zervas and Sessler was made by the reaction of l12-isopropylidene-a-D-glucofuranose with benzaldehyde and phosphorus pentoxide a t room temperature. The procedure was a modification of the method of Brigl and Grune1-3~ who used zinc chloride as the condensing agent in the original synthesis of this substance. Recently Akiya and Watanabe3? claimed to have improved Zervas and Sessler's36 method for the synthesis of D-glucuronic acid through ll2-iso~ro~ylidene-3,5-benzyl~dene-~-g~ucof~ranose. These investigators prepared the latter compound by the following series of reactions: 1,2-isopropylidene-a-~-glucofuranose -+ 1,2-isopropylidene-~-glucose3,5(35) L. Zervas and P. Sessler, Ber., 66, 1326 (1933). (36) P. Brigl and H. Griiner, Ber., 66, 1428 (1932). (37) S. Akiya and T. Watanabe, J . Pharm. SOC.J a p a n , 67, 99 (1947); Chem. Abstracts, 45, 9483 (1951).
238
C. L. MEHLTRETTER
boric ester -+1,2-isopropylidene-6-acetyl-~-glucose + l12-isopropylidene3,5-benzylidene-6-acetyl-~-glucose -+ 1,2-isopropylidene-3,5-benzylideneD-glUCOSe. Permanganate oxidation of 1,2-isopropylidene-3,5-ben~ylidene-~glucose, and hydrolysis of the resulting n-glucuronic acid derivative by essentially Zervas and Sessler’s procedure, gave a twelve and one-half percent overall yield of D-glucuronolactone from n-glucose. 37s An attempt t o oxidize directly the intermediate 3,5-boric acid ester doubtless was discouraged by the result obtained by v. VarghaS8in 1933, wherein potassium permanganate oxidation of the 3,5-monoborate of IJ-isopropylidene-D-glucofuranose in acetone solution had produced potassium 1,2-isopropylidene-~-xyluronaterather than the expected D-glucuronic acid derivative. In 1951 Ishidate and Okada39 prepared l12-cyclohexylidene-3,5benzylidene-D-glucuronic acid in eighty-eight percent yield from 1,2cyclohexylideize-3,5-benzylidene-~-glucoseby permanganate oxidation, Subsequently hydrolysis of the glucuronic acid derivative by a mixture of ethanol and hydrochloric acid produced D-glucuronolactone from D-glucose in an overall yield of approximately twenty-two percent. Acid hydrolysis under less stringent conditions, as well as catalytic reduction, in crystalgave the intermediate 1,2-cyclohexylidene-~-glucuronolactone line form, This compound appears to be identical with that prepared by Mehltretter40 by catalytic, air oxidation of 1,2-cyclohexylidene-cu-~glucofuranose. Protection of the hydroxyl groups in D-glucose in the preparation of D-glucuronic acid has also been effected by derivatives other than cyclic acetals. I n an earlier synthesis Stacey4I had prepared 1,2,3,4-tetraacetyl-6-trityl-~-ghlcose (X) from D-glucose by a modification of the procedure devised by Helferich, Moog and Junger. 42 Detritylation by the procedure of Helferich and Klein43yielded 1,2,3,4-tetraacetyl-j3-~glucose (XI), which upon oxidation in glacial acetic acid-acetone solution with permanganate gave 1,2,3,4-tetraacetyl-~-glucuronicacid (XII). (37a) For comparison of yields of D-glucuronolactone obtained by the methods which utilize 1,2-isopropylidene-a-D-glucofuranoseas an intermediate, all calculations are based on D-glucose with the assumption of a yield of sixty-nine percent, as obtained by Zervas and Sess1er,86for the preparation of l,%isopropylidene-a-D-gIucofuranose. (38) L,v. Vargha, Ber., 66,704 (1933). (39) M. Ishidate and M. Okada, J . Pharm. SOC.Japan, 71, 1163 (1951); Chem. Abstracfs, 46,4996 (1952). (40) C. L. Mehltretter, unpublished work. (41) M. Stacey, J. Chem. SOC.,1529 (1939). (42)L. Helferich, L. Moog and A. Jiinger, Ber., 68,872 (1925). (43) B. Helferich and J. Klein, Ann., 460,219 (1926).
CHEMICAL SYNTHESIS O F D-GLUCURONIC ACID
239
Deacetylation of the substituted glucuronic acid with aqueous barium hydroxide yielded barium D-glucuronate. After removal of barium with sulfuric acid, the aqueous solution of D-glucuronic acid was evaporated in vacuo to a sirup, which crystallized upon seeding with authentic D-glucuronolactone. An overall yield of D-glucuronolactone of twenty percent was obtained.
-I
AcOCH
HbOAc
b
AcobH
H OAc
b-
AcO H HbOAc
+ ACOAK
b-
AcobH + b
H OAc
AcO H
HAoAc
HbOAc
Derivatives of D-glucose in which all the secondary hydroxyl groups are not blocked have been used chiefly in attempts to devise an economical process for the large-scale manufacture of D-glucuronic acid. Recent patents report methods for producing D-glucuronic acid by alkaline permanganate oxidation of soluble starch, 4 4 and of D-glucose derivatives in which the aldehyde function is protected. 4 6 Gallagher claimed t o have effected some degree of preferential oxidation of the primary alcohol group in both methyl a-D-glucopyranoside and 1,2-isopropylidene-a-D-glucofuranose under conditions of relatively high alkalinity and low temperature. Yields of methyl D-glucuronoside and of 1,2-isopropy~idene-~-g~ucuron~c acid were reported to be, respectively, sixty and thirty-four percent of theory as determined by colorimetric analysis of the reaction mixture by the naphthoresorcinol method. However, t.he claims are not convincing, since the products were not8 isolated and characterized. Furt,hermore, by-product uronic produced by oxidative degradation of the D-glucose derivatives at unshielded positions, are also capable of giving a positive naphthoresorcino1 test erroneously indicative of the presence of D-glucuronic acid. 2. Nitrogen Dioxide Maurer and ~ o w o r k e rfound s ~ ~ ~that ~ ~nitrogen dioxide in non-aqueous solution is capable of selectively oxidizing the primary alcohol group (44) T. Ohmori, Japanese Pat. 179,069 (1949); Chem. Abstracts, 46, 1585 (1952). (45) D. M, Gallagher, U. S. Pat. 2,592,266 (1952). (46) (a) K. Maurer and H. Reiff, J . Makromol. Chem., 1, 27 (1943); (b) K. Maurer and G. Drefahl, Ber., 80, 94 (1947).
240
C. L. MEHLTRETTER
of carbohydrates. Their initial experiment indicated that acetal formation, with the aldehyde function of glycolaldehyde, adequately protected that portion of the molecule from oxidation by nitrogen dioxide in chloroform or carbon tetrachloride solution. Accordingly, they oxidized methyl a-D-glucopyranoside,12 and upon hydrolysis of the reaction mixture presumed to have obtained barium D-glucuronate in sixty-seven percent yield. Their conclusion, however, was based solely on barium analyses of the salt, rather than on unequivocal proof by the isolation of crystalline D-glucuronolactone or some other suitable derivative of D-glucuronic acid. The oxidation of methyl a-~-galactopyranoside~~(~) in the same manner was more precise, in that the galacturonoside was recovered as amorphous calcium (methyl wga1actopyranosid)uronate in a yield of eighty percent and was obtained in crystalline form from the latter salt. In spite of numerous trials, Mehltretter4’ was unable to achieve the yield of barium n-glucuronate reported by Maurer and Drefahl.I2 Hardegger and spit^,^^ likewise, obtained only a small quantity of D-glucuronic acid as the lactone, through nitrogen dioxide oxidation of methyl a-D-glucopyranoside, and stated that the synthesis in its present form is not suitable as a preparative procedure. Considerably more oxidation occurred with the P-an~rner*~ but only small amounts of crystalline derivatives of methyl P-D-glucopyruronoside were isolated, while a seventy percent yield of organic acids was reported. A substantial portion of the latter was found t o be wglucosaccharic acid, which was not observed in the oxidation products from methyl a-D-ghcopyranoside. In 1950, two patents were issued to Peterman on methods for synthesizing D-glucuronic acid by nitrogen dioxide oxidation of glucosides. In one processlLoG) methyl D-ghcopyranoside was oxidized with a mixture of nitrogen dioxide gas and oxygen. The crude methyl D-glucuronoside obtained was hydrolyzed with one percent sulfuric acid at 90’ for one hour, to produce n-glucuronic acid. A theoretical yield of D-glucuronic acid was claimed. This is surprising, since it is known that approximately fourteen hours is required to hydrolyze completely the hemiacetal linkage in methyl a-D-hexuronosides with half-normal sulfuric acid at reflux temperature, 61 and that extensive degradation of the liberated uronic acid occurs during this period. The high yield of D-glucuronic (47) C. L. Mehltretter, unpublished work. (48) E. Hardegger and D. Spits, Helu. Chim. Aetca, 32, 2165 (1949). (49) E. Hardegger and D. Spite, Helu. Chim. Acta, 33, 337 (1950). (50) (a) E. A. Peterman, U. 5. Pat. 2,520,255 (1950);(b) U. S. Pat. 2,520,256 (1950). (51)F. Ehrlich and R. Guttmann, Ber., 66, 220 (1933).
CHEMICAL SYNTHESIS O F D-GLUCURONIC ACID
241
acid claimed by Peterman is in marked contrast to that found by previous investigator^.^^.^^ A second p r o c e ~ s describes ~ ~ ( ~ ) the oxidation of ethyl D-glucopyranoside by nitrogen dioxide in chloroform solution over a period of eight days at 20°C. When the reaction was completed the supernatant liquor was decanted and the residual gummy ethyl D-glucuronoside was dissolved in absolute alcohol. The solution was vacuum distilled to a dry product, which was claimed t'o be eighty to one hundred percent ethyl D-glucuronoside. Acid hydrolysis of the glucuronoside with one percent sulfuric acid at elevated temperature produced a mixture of D-glucuronic acid and furfural, the latter of which was removed by condensation with barbituric acid. A more recent patentb2 relates to the production of D-glucuronic acid by oxidation of methyl D-glucopyranoside with liquid nitrogen dioxide. An optimum yield of ~-glucuronicacid was obtained when the reaction was carried out at 20°C. for nine hours. The crude methyl D-glucuronoside was removed from aqueous solution by an anion-exchange resin. It was then eluted from the resin with dilute sulfuric acid, and the resulting solution was refluxed for sixteen hours t o produce D-glucuronic acid. After impurities were removed by extraction with l-butanol, the aqueous solution was concentrated to small volume and D-glucuronolactone crystallized by the addition of glacial acetic acid. From the data given, the yield of crystalline product was seventeen percent of theory. The use of nitrogen dioxide for the selective oxidation of polysaccharides to polyuronic acids was introduced by Kenyoii and his c ~ w o r k e r s ' ~ ~ ~ ~ in 1941. By this means extensive oxidation of the primary alcohol groups in cellulose was obtained, through the mechanism of preferential nitration followed by decomposition of the nitric acid ester with carboxyl format i ~ n . ~ ~ ( ' )Apparently *(~) some undissociated nitration products also were formed, since infrared absorption studies54 indicated the presence of nitrate radicals in the polyuronic acid. Side reactions produced carboxyl, (52) D. H. Couch and E. A. Cleveland, U. S.Pat. 2,592,249 (1952). (53) (a) E. C. Yackel and W. 0. Kenyon, J . Am. Cheni. SOC.,64, 121 (1942); (b) C. C. Unruh and W. 0. Kenyon, ibid., 64,127 (1942); ( c ) E. W. Taylor, W. F. Fowler, Jr., P. A. McGee and W. 0.Kenyon, ibid., 69, 342 (1947); (d) 1'. A. McGee, W. F. Fowler, Jr., and W. 0. Kenyon, ibid., 69, 347 (1947); (e) C. C. Unruh, P. A. McGee, W. F. Fowler, Jr., and W. 0. Kenyon, ibid., 69, 349 (1947); (f) P. A. McGee, W. F. Fowler, Jr., E. W. Taylor, C. C. Unruh and W. 0. Kenyon, ibid., 69, 355 (1947); ( 9 ) P. A. McGee, W. F. Fowler, Jr., C. C. Unruhand W. 0. Kenyon, ibid., 70,2700 (1948); (h) E. C. Yackel and W. 0. Kenyon, U. S. Pat. 2,448,892 (1948); (i) W. 0. Kenyon and W. F. Fowler, Jr., Abstracts Papers Am. Chem. SOC.,118, 4R (1950). (54) J. W. Rowen and E. K. Plyler, J . Research Nall. Bur. Standards, 44, 313 (1950).
242
C. L. MEHLTRETTER
aldehyde, and ketone groups from the secondary hydroxyl positions of the polysaccharide.6a(g)t66 Although the uronic acid content of cellulose oxidized by nitrogen dioxide was found to be high,6s(a),(d),(n),66,66(a),(b) satisfactory acid hydrolysis to D-glucuronic acid has not yet been achieved. Starch also has been oxidized with nitrogen dioxide.67 As expected, the product obtained by oxidation with nitrogen dioxide in carbon tetrachloride at room temperature gave a qualitative naphthoresorcinol test for D-glucuronic acid. No quantitative data are available, however, on the hydrolysis of such polyglucuronosides to D-glucuronic acid. A wider variety of oxidation products can be anticipated from corn starch, since it is composed of a linear or amylose fraction, present to the extent of about twenty-five percent and containing predominantly a-ll4-glucosidic linkages, and a branched or amylopectin fraction whose branches are considered to be formed mostly through a-1,6-glucosidic linkages. Kerr6’cd)has shown that amylose oxidized with gaseous nitrogen dioxide has significantly more anhydroglucuronic acid units than amylopectin that had been similarly treated. Whole starch, oxidized in the same manner, gave an amount of uronic acid intermediate between those obtained with the two fractions. From a practical point of view, nitrogen dioxide is not a satisfactory oxidant for the preparation of D-glucuronic acid. Anhydrous conditions of reaction are generally necessary and the oxidation progresses slowly. Periods of a t least nine hours are required for completion of an oxidation when liquid nitrogen dioxide is used. Reactions with nitrogen dioxide in chloroform solution or in the gaseous state take a number of days. Side reactions occur to some extent, and lower the yield of the main product. 3. Catalytic Oxidation by Oxygen The oxidation of aliphatic aldehydes and primary alcohols t o acids by use of oxygen in the presence of noble-metal catalysts, has long been known.68 Its application, however, to the preferential oxidation of aldehyde and primary alcohol groups in carbohydrates is quite recent. In 1941 B u s ~ hquantitatively ~~ converted D-glucose to D-gluconic acid with air, using a palladium-impregnated, calcium carbonate catalyst and (55) T. P. Nevell, J . Textile I d . , 43, T91 (1951). (56) (a) A. S. Perlin, Can. J . Chem., SO, 278 (1952); (b) P. Hirsch, Rec. truu. chim., 71, 999 (1952). (57) (a) W. 0.Kenyon and C. C. Unruh, U. S. Pat. 2,472,590 (1949); (b) J. W. Mench and E. F. Degering, Proc. Indiana Acad. Sci., 66, 69 (1945); (c) J. E. Pierce and E. F. Degering, Abstracts Papers Am. Chem. Soc., 113, 17D (1947); (d) R. Kerr, J . Am. Chem. Soc., 73, 816 (1950). (58) J. Houben, “Die Methoden der Organischen Chemie,” 3rd ed., 1952, p. 22. (59) M. Busch, German Pat. 702,729 (1941).
CHEMICAL SYNTHESIS O F D-GLUCURONIC ACID
243
the theoretical amount of alkali for neutralization of the acid. Somewhat later, Heyns and Heinemannso prepared D-gluconic acid in analogous manner with a platinized-carbon catalyst. With this more active catalyst, Dalmer and Heynsll*slwere able to oxidize L-sorbose, under neutral or slightly alkaline conditions, to 2-keto-~-gulonic acid for the production of ascorbic acid. Similarly, Trenners2 converted 2,3-isopropylidene-L-sorbose in aqueous solution to 2,3-isopropylidene-2-ketoL-gulosaccharic acid. The oxidation of D-glucose to D-glucosaccharic acid in fifty-four percent yield also has been carried out with this catalyst,68although Heyns and HeinemannG0were unable to detect D-glucosaccharic acid as an oxidation product of D-glucose in their experiments. Mehltretter, Alexander, Mellies and Rist l 4 then prepared D-glucuronic acid through catalytic oxidation of 1,2-isopropy~idene-a-~-glucofuranose (XIII). The intermediate 1,2-isopropylidene-~-glucuronic acid (XIV), obtained in fifty to sixty percent yield, was hydrolyzed quantitatively to D-glucuronic acid, which was isolated as the crystalline lactone. An overall yield of t,hirty percent of D-glucuronolactone, based on D-glucose, has consistently been realized by these investigators. A similar study reported at approximately the same time by Col6n and his associatesa4 7
-
I
HCOH
I CHzOH XI11
1
I
I
HCOH
bOOH XIV
Direct hydrolysis attained only half' this amount of D-glucuronolactone. of the oxidation mixture, after the removal of cations by ion exchange, produced a sirup from which an overall yield of approximately fifteen percent of crystalline D-glucuronolactone, based on D-glucose, was obtained. (60) (61) (62) (63)
K. Heyns and R. Heinemann, Ann., 668, 187 (1947). K. Heyns, Ann., 668, 177 (1947). N. R. Trenner, U. S. Pat. 2,428,438 (1947); 2,483,251 (1949). C. L. Mehltretter, C. E. Rist and B. H. Alexander, U. S. Pat. 2,472,168
(1949). (64) R. Fernandez-Garcia, L. Amoroa, Hilda Blay, E. Santiago, Hilda SolteroDiaz and A. A. Col6n, El Crisol, 4, 40 (1960).
244
C. L. MDHLTRETTER
Because the synthesis by catalytic oxidation represents the most satisfactory preparative method t o date for D-glucuronolactone, it will be described more elaborately than the previously mentioned procedures. The oxidation of 60 grams of 1,2-isopropy~idene-a-n-glucofuranose in 900 milliliters of water was carried out in the presence of 6.8 grams of platinum-activated carbon catalyst which contained 13 percent of platinum by weight. After being heated to 50°C., the mixture was vigorously stirred at about 3,500 r.p.m., while introducing air at the rate of 112 liters per hour. A volume of 10 percent sodium hydroxide solution, which represented the theoretical quantity of alkali for the complete conversion of 1,2-isopropy~idene-a-~-glucofuranose t o sodium 1,2-isopropylidene-~glucuronate, was immediately added dropwise to maintain the pH of the reaction mixture at 8-9 throughout the addition. All of the alkali generally was introduced in one to two hours, after which the pH of the oxidation mixture was allowed to decrease to 7. The reaction was then stopped, the light-brown solution filtered from catalyst, and the latter washed with hot dilute sodium chloride solution to prevent colloid formation and loss of platinum. The combined filtrate and washings were concentrated in vucuo t o approximately 200 milliliters and oxalate ions were precipitated by the addition of 2 grams of calcium chloride. The addition to the filtered mixture of 13 grams of calcium chloride in concentrated aqueous solution caused almost immediate crystallization of calcium 1,2-isopropylidene-~-glucuronate.After filtration, the product was washed with 50 percent ethanol and air dried, t o yield 41.8 grams hydrate. . (fifty-three percent) of calcium 1,2-isopropylidene-~-glucuronate The fairly pure calcium salt was treated with the theoretical quantity of oxalic acid to precipitate calcium oxalate and liberate 1,24sopropylideneD-glucuronic acid. Hydrolysis of the filtered solution at 90-100" for two hours gave D-glucuronic acid quantitatively, as determined by the reducing power of the solution. The nearly colorless hydrolyzate was concentrated on the steam bath to crystallization of D-glucuronolactone in eighty percent yield. Slightly more D-glucuronic acid was obtained when barium 1,2-isopropylidene-~-glucuronatewas precipitated from the oxidation mixture in lieu of the calcium salt. were Calcium, barium and sodium 1,2-isopropylidene-~-glucuronates prepared from authentic 1,2-isopropylidene-~-glucuronicacid. The crystalline calcium salt contained 5.5 molecules of water and had [a],z6 - 1-54" ( 6 , 1.97, water), while the barium salt was a monohydrate insoluble in water. The anhydrous sodium salt had [aIDz6-2.58' (c, 10.74, water). Catalytic oxidation of 1,2-cyclohexylidene-~-glucofuranoae~~ in an (65) R. C. Hockett, R. E. Miller and A. Scattergood, J . Am. Chem. Soc., 71,3072 (1949).
CHEMICAL SYNTHESIS O F D-GLUCURONIC ACID
245
analogous manner yielded the sodium salt of 1,2-cyclohexylidene-~glucuronic acid in solution. Addition of calcium chloride to the filtered and concentrated oxidation mixture precipitated relatively insoluble crystalline calcium 1,2-cyclohexylidene-~-glucuronate.Removal of calcium with sulfuric acid and concentration of the solution to dryness gave a sirup, which was extracted with hot ethanol. On cooling the extract, 1,2-cyclohexylidene-~-glucuronolactonec r y ~ t a l l i z e d . ~D-Glucuronolac~ tone was prepared from this substance by hydrolysis and evaporation to crystallization. Oxidation of the anomers of methyl D-glucopyranoside, D-galactopyranoside, D-mannopyranoside,6E(8)~(”) Z-menthyl ~-glucopyranoside,~’ and of 2-naphthyl P-D-g1ucopyranosidee8to their corresponding D-glycuronosides has also been readily achieved by this method. Acid hydrolysis of the glucuronosides, however, left much to be desired, and produced D-glucuronolactone in relatively low yield. In Mehltretter’s synthesis66(8) the oxidation mixture containing the sodium salt of methyl a-D-glucuronoside was adjusted to pH 2 with sulfuric acid and concentrated in vacuo to dryness. The crude methyl a-D-ghcuronoside was separated from sodium sulfate by extraction with hot methanol. After removal of solvent, the glucuronoside was hydrolyzed with N sulfuric acid at 95-100” for fifteen hours to yield a relatively small quantity of n-glucuronic acid. Sulfuric acid was removed as barium sulfate and the crude D-glucuronic acid solution was neutralized wit.h sodium hydroxide and concentrat.ed in vacuo to small volume. An alcohol solution of aniline was then introduced and the mixture adjusted to approximately pH 4 with acetic acid to enhance crystallization of the sodium salt! of aniline D-glucuronoside. The salt in dilute acetic acid solution was heated to generate aniline, which was removed by solvent extraction or steam distillation. The aniline also could be eliminated by Schiff-base formation with benzaldehyde, followed by ether extraction of the benzalaniline. The resulting aqueous soIution was concentrated, and sodium D-glucuronate monohydrate was conveniently crystallized by the addition of ethanol, a yield of fourteen percent, based on methyl D-glucopyranoside, being obtained. Neutralization with potassium or ammonium hydroxide instead of sodium hydroxide, before reaction with aniline, resulted in the precipitation of potassium6g or ammonium salts of aniline D-ghcuronoside. (66) (a) C. L. Mehltretter, U. S. Pat. 2,562,200 (1951); (b) S. A. Barker, E. J. Bourne and M. Stacey, Chemistry & Industry, 970 (1951). (67) C. A. Marsh, Nature, 168, 602 (1951); J. Chern. SOC.,1578 (1952). (68) K. C. Tsou and A. M. Seligman, J . Am. Chem. SOC.,74, 5605 (1952). (69) H. Thierfelder, 2.physiol. Chem., lS, 275 (1889).
246
C. L. MEEILTRETTER
Recently Smith and William~'~described a p-toluidine-ammonium D-glucuronate complex, containing one mole of toluidine and one mole of the toluidide of ammonium D-glucuronate, which might have utility in the recovery of D-glucuronic acid from glucuronoside hydrolyzates. Little is known about the configuration and properties of the salts of arylamine D-glucuronosides, and investigations paralleling those of Howard, Kenner, Lythgoe and Todd7' with amine glycosides would appear t o be desirable. The catalytic oxidation of methyl- a-D-glucopyranoside by Barker, Bourne and Staceys6ch)yielded eighty-seven percent of the glucuronoside, which upon hydrolysis gave an overall yield of sixteen percent of D-glucuronolactone. Methyl p-D-glucopyranoside upon oxidation produced glucuronoside to the extent of sixty-eight percent of theory. Formic acid hydrolysis of the latter subst,ance gave an overall yield of D-glucuronolactone of fifteen percent. Only a small amount of D-glucuronolactone was obtained by hydrolysis of the glucuronate secured through oxidation of dipotassium a-D-glucose 1-phosphate. The weak link in any synthesis of D-glucuronic acid which employs methyl a-D-glucopyranoside is the degradation of D-glucuronic acid which takes place during the hydrolysis step. To obtain a more efficient hydrolysis, Barker, Bourne and Stacey66(b)have suggested oxidation of the more easily cleaved methyl D-ghcofuranosides, or enzymic splitting of a salt of D-glucuronic acid 1-phosphate. p-D-Glucuronidase has been utilized for the hydrolysis of phenolphthalein p-D-glucuronoside,T2 I - m e n t h ~ l ~and ~ ( ~phenyl ) & ~ - g h c u r o n o s i d e s , and ~ ~ ~2-naphthyl ~) 8-D-glucopyranuronoside. 68 The successful application of catalytic oxidation by air or oxygen t o the preparation of uronic acids depends on a number of factors which are discussed below. (1) The activity of the platinum-carbon catalyst is of prime concern in obtaining maximum yields of product in a minimum of time. It was found by Mehltretter and his associatesI4that a modification of Trenner's procedures2consistently produced an effective catalyst. In the modified method, platinum from an aqueouR solution of chloroplatinic acid was deposited on acid-washed Darco (2-60brand of activated carbon by means of formaldehyde and sodium carbonate. To maintain high activ(70) J. N. Smith and R. T. Williams, Biochem. J., 44, 250 (1949). (71) G. A. Howard, G. W. Kenner, B. Lythgoe and A. R. Todd, J . Chem. SOC.,855 (1946). (72) P. Talalay, W. A. Fishman and C. Huggins, J . Biol. Chem., 166, 757 (1946). (73) (a) G. A. Levvy, Biochem. J., 42,2 (1948); (b) L. M. H. Kerr, A. F. Graham and G. A. Lewy, Biochem. J . , 42, 191 (1948).
CHEMICAL SYNTHESIS O F D-GLUCURONIC ACID
247
ity of the catalyst the reactants in the oxidation must be extremely pure. Mehltretter has used the same catalyst for at least five oxidations of 1,2-isopropy~idene-a-~-glucofuranose before it became sufficiently inactive to require replacement. Poisoning of the catalyst was relatively insignificant in repeated oxidations of recrystallized methyl a-D-glucopyranoside. (2) Heterogeneous reactions of this type require vigorous agitation t o obtain increased contact of the catalyst with the aerated aqueous solution of the carbohydrate. The use of creased flasks and high-speed stirring enabled oxidations to be carried out efficiently in small-scale experiments. For the oxidation of several liters of solution, however, the employment of 8 turbo-mixer was more practical. In such cases the heat of reaction was great enough to require cooling of the mixture t o maintain a constant temperature of 50-60” throughout the oxidation. Satisfactory oxidations were obtained with stirrer speeds of 3,500 r.p.m. but doubtless the rate of reaction can be increased significantly by even greater a g i t a t i ~ n . ’ ~Other ways to enhance the reaction rate are t80 increase (a) the ratio of catalyst t,o t.he subst,ance being oxidized, (b) the air flow or air pressure during the reaction, and (c) the temperature of the reaction. The extent of their use, however, is limited by such factors as cost, design of equipment, and the occurrence of majorside reactions. 4. Use of Other Oxidants
Early methods for preparing D-glucuronic acid from D-glucose or D-glucosides utilized hydrogen peroxide or the halogens as oxidizing agents, in neutral or alkaline solution. The syntheses developed, however, proved to be unsat,isfactory because of the low yields obtained in both the oxidation and hydrolysis stages. One of the first attempts to use hydrogen peroxide in such a synthesis was made by J01les.’~ A two-percent solut,ion of D-glucose was oxidized over an extended period of time but only an insignificant quantity, if any, of D-glucuronic acid was detected in the oxidation mixture. I n 1924 Smolenski7Bdevised a procedure in which a twenty to thirty percent yield of methyl a-D-glucuronoside was obtained by hydrogen peroxide oxidation of methyl a-D-glucopyranoside. Fifteen years elapsed before the use of hydrogen peroxide was again reported for the preparation of D-glucuronic acid. By means of hydrogen peroxide generated at, the cathode of an electrolytic cell, Leutgoeb and Heinrich7I converted (74) (75) (76) (77)
A. W. Hixson, Ind. Eng. Chern., 36,488 (1944). A. Jolles, Biochem. Z., 34, 243 (1911). K. Smolenski, Roczniki Chemji, 3, 153 (1924); Chem. Abstracts, 19,41 (1925). R. A. Leutgoeb and H. Heinrich, J . A m . Chem. Soc., 61, 870 (1939).
248
C.
L. MEHLTRETTER
methyl a-D-glucopyranoside to the corresponding wglucuronoside. PGlucuronic acid was recovered as its cinchonine salt in low yield after hydrolysis of the glucuronoside. The preparation of D-glucuronic acid by hydrogen peroxide oxidation of soluble has also been investigated. Hydrolysis of the polyuronide with sulfuric or oxalic acid gave D-glucuronic acid, which was isolated as the crystalline lactone. The preparation of glucuronosides by halogen oxidation of D-glucosides was first reported by Bergmann and Wolff ,78 Menthyl a-D-glucopyranoside in pyridine solution was subjected to the action of sodium hypobromite in dilute aqueous alkali, and gave only a low yield of the glucuronoside. When methyl a-D-glucopyranoside was treated with proportionately more barium hypobromite in aqueous barium hydroxide solution, the hydrolyzed reaction mixture gave a high reducing value and a pronounced naphthoresorcinol test for D-glucuronic acid, However, only the crystalline benzylphenylhydrazone of glyoxylic acid could be isolated from the hydrolyzate. The following year, Sm0lenski7~claimed the preparation of methyl D-ghcuronoside in nearly thirty percent yield by alkaline hypobromite oxidation of methyl a-D-glucopyranoside. Further illustration of the inadequacy of hypobromite oxidation for the conversion of glycosides to uronides is the work of Jackson and Hudson.79 Only a twelve percent yield of the brucine salt of methyl a-D-mannuronoside was obtained because of oxidative cleavage of the carbon chain of methyl a-D-mannopyranoside. A number of workers have investigated the oxidation of dextrinssO and starchs1 with halogens in neutral and alkaline solutions and have reported the presence of significant amounts of anhydroglucuronic acid units in the products obtained, as determined by furfural formation. No attempt has been made, however, to develop a practical synthesis of wglucuronic acid by this means. Sowden82recently has prepared n-glucuronic acid isotopically labeled a t carbon atom 6 for certain chemical and biochemical studies. In this novel synthesis, 5-aldehydo-1,2-isopropylidene-~-xylofuranose** (XVI), prepared by periodate cleavage of 1,2-isopropy~idene-a-~-glucofuranose (XV), was condensed with V4-1abeled sodium cyanide. Alkaline (78) M.Bergmann and W. Wolff, Ber., 66, 1060 (1923). (79)E.L. Jackson and C. S. Hudson, J . Am. Chem. Soc., 69,994 (1937). (80) W.Syniewski, Ann., 441, 277 (1925). (81) G. Felton, F. F. Farley and R. M. Hixon, Cereal Chem., 16, 678 (1938); F. F. Farley and R. M. Hixon, I d . Ens. Chem., 34, 677 (1942);C. Dumazert and H. Lehr, Trav. membres. soc. chim. biol., 23, 1284 (1941), B i d . Abatrmts, 21, 2373 (24202)(1947). (82)J. C. Sowden, J . Ana. Chem. Soc., 74,4377 (1952). (83) K.Iwadare, BUZZ. Chem. SOC.Japan, 16, 40 (1941).
CHEMICAL SYNTHESIS O F D-GLUCURONIC
ACID
249
hydrolysis of the cyanohydrin (XVII) gave sodium 1,2-isopropylidene-~glucofuranuronate (XVIII). Ion exchange of this salt to remove sodium ions produced the free acid, which was lactonized to 1,2-isopropylidene-~glucofuranurono-y-lactone (XIX). Isolation of XIX in high yield indi-
HCOH I
CHO
I
k*N
~H,OH
xv
XVI
XVII
I
H c o l/CH3
1 y\
I
HO~H
I
HCO
HCO-O&H
I HCO.
CHs
I--*
HC
I
HLOH
I
C*OONa XVIII
H~OH
I
-c*o XIX
HboH
I -c*o xx
cated that only a minor quantity of the diastereoisomeric nitrile was formed during the cyanohydrin reaction. Hydrolysis and lactonization of X I X gave, quantitatively, ~-glucuronolactone-6-C'4 ( x x ) .
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D-GLUCURONIC ACID IN METABOLISM
BY H. G. BRAY Department of Physiology, Medical School of the University, Birmingham, England
CONTENTS I. 11. 111. IV. V. VI. VII.
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-Glucuronide Formation in Viuo.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Structure of Glucuronidee.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Origin of D-Glucuronic Acid and Mechanism of D-Glucuronide Synthesis. . . Site of D-Glucuronide Formation.. ................................... Kinetics of D-Glucuronide Formation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Enzymes and D-Glucuronide Formation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
251 252 254 257 259 260 261
I. INTRODUCTION Of the three naturally occurring hexuronic acids, D-glucuronic acid appears t o be by far the most widely distributed. It has not been found free in ru’ature, except possibly in small amounts in blood and urine,1.2.8 but it occurs in a wide variety of polysaccharides and mucoproteins of plant, animal-and bacterial origin, and plays an important part in the metabolism of many types of organic compounds. As early as 1855 it was obtained as a copper-reducing substance from euxanthic acid14 the D-ghcuronide of euxanthone (3,6dihydroxyxanthone), which is excreted as a metabolic conjugation product when euxanthone is administered to animals, and Baeyer in 18706 suggested that it was a type of saccharic acid. Sustained interest in D-glucuronic acid dates from about 1875 when von Mering and Musculus6 showed it to be a component of urochloralic acid, a metabolite of chloral hydrate, and Jaff 67 isolated it from a metabolite of o-nitrotoluene. Later Schmiedeberg and Meyer8 obtained ,D-gIucurone from camphor-D-glucuronic acid, a metabolite of camphor. Gladys J. Fashena and H. A. Stiff, J . Biol. Chem., 187,21 (1941). P. Mayer, 2. physiol. Chem., 82, 518 (1901). R. Lepine and R. Boulud, Compt. Tend., 188, 138; 184, 398 (1901). W. Schmid, Ann., QS,83 (1855). A. Baeyer, Ann., 166, 257 (1870). J. von Mering and 0. Musculus, Ber., 8, 662 (1875). M . Jaffd, 2.phpiol. Chem., 8, 47 (1878-9). (8) 0. Schmiedeberg and H. Meyer, Z. physiol. Chem., 8, 422 (1879). 26 1 (1) (2) (3) (4) (6) (6) (7)
252
€ a. I.BRAY
The structural relationship of D-glucuronic acid to D-glucose was established by Fischer and Pilotye in 1891 when they obtained it by reduction of D-saccharic acid with sodium amalgam. The first glucuronides to be synthesized appear to have been those of phenol and euxanthone, which Neuberg and Neimann‘O prepared by the action of the “acetobromo” derivative of D-glucuronolactone on the potassium salts of the phenols in methanolic solution. Since the early years of this century a large number of biosynthetic D-glucuronides have been isolated and numerous investigations into the origin of D-glucuronic acid and the mechanism of D-glucuronide formation have been made. It is mainly with these topics that this article will be concerned. 11. D-GIJJCURONIDE FORMATION in Vivo In the fields of biochemistry and pharmacology interest in n-glucuronic acid has centered round the part it plays in the metabolism of drugs and other foreign organic compounds. While the ability of the organism to synthesize D-glucuronic acid in response t o the administration of such compounds is truly remarkable, the extent to which it participates in normal metabolism is virtually unknown, except for the fact that it is concerned in the metabolism of certain steroid sex hormones (see e. 8. reference 11). This function appears t o be similar t o that involved in the metabolism of foreign organic compounds and throws no light on the part, if any, which it plays in carbohydrate metabolism in-general. From a theoretical standpoint, D-glucuronides may be regarded as being formed by the elimination of water between the hydroxyl group of position 1 of D-glucuronic acid and either the hydroxyl group of a phenol or alcohol or the carboxyl group of an acid. In this way two types of D-glucuronide arise, which are illustrated by formulas I and 11. COOH
I
COOH
I1
A typical glucuronide of type I is bensoyl p-D-glucuronide (R = CaH6-) and of type I1 phenyl p-wglucuronide (R = CsHb-), which are, respectively, metabolites of benzoic acid and phenol in most species. Glucuronides of types I and I1 are often designated “ester” and “ether” (9) E. Fisoher and 0. Piloty, Ber., 24, 521 (1891).
(10) C. Neuberg and W. Neimann, 2.physiol. Chem., 44, 114 (1905). (11) W.H.Fishman, Vitamins and Hormones, 8, 226 (1951).
D-OLUCURONIC ACID I N METABOLISM
253
glucuronides, respectively. Ester glucuronides are, in general, directly reducing to alkaline copper reagents, on account of the alkali-lability of the glycosidic link, while most ether glucuronides, especially if R is an aromatic grouping, are not reducing unless previously hydrolyzed by acid. The designation “ether glucuronides ” is questionable because the substances are really glycosides or acetals rather than true ethers. The preliminary evidence for the metabolic formation of a glucuronide by a compound administered t o an animal is usually the observation of an increase in the reducing power of the urine before or after hydrolysis, or in the uronic acid content as determined by a naphthoresorcinol method. Normal urine contains a small amount of reducing material, part of which is D-glucuronic a ~ i d , ~but - ~this ~ -may ~ ~be increased several fold when glucurogenic compounds are administered or formed in vivo from administered compounds. There is no evidence to suggest that the resources of the animal body which produce D-glucuronic acid for purposes of conjugation can be exhausted by any dosage which the animal will tolerate. This synthetic capacity of most species, and especially of the rabbit, provided the most convenient source of D-glucuronic acid (see e. g. reference 15) until synthetic D-glucuronic acid became readily available. The percentage of the dose of an administered compound excreted as D-glucuronide depends on several factors, such as the nature of the compound and the magnitude of the dose, and can range from a very small value to 60-707, in the case of certain phenols and terpenes. Evidence of D-glucuronide formation has been obtained for compounds too numerous t o mention. In a large number of cases crude non-crystalline glucuronide-containing material has been isolated and in many instances the glucuronides themselves or derivatives of them have been obtained crystalline. The most usual method of isolation of glucuronides from urine makes use of the insolubility of their basic lead salts, which are precipitated and decomposed with hydrogen sulfide. The details of this procedure have been described frequently (see e. g. reference 16). Some glucuronides can be isolated from metabolic urines directly by extraction with a solvent, e. g. xylenyl glucuronides, which are soluble in ether, and (12) (13) (1938). (14) (15) (16) (17) (1960).
W. B. Deichmann, J . Lab. Clin. Med., 28, 770 (1943). G. B. Maugham, K. A. Evelyn and J. S. L. Browne, J. Biol. Chem., 126, 567
P. Mayer and C. Neuberg, 2. physiol. Chem., 29, 256 (1900). R. T. Williams, Biochem. J., 34, 272 (1940). H. G. Bray, Brenda E. Ryman and W. V. Thorpe, Biochem. J.,41,212 (1947). H. G. Bray, Brenda G. Humphris and W. V. Thorpe, Biochem. J., 47, 395
254
H. 0 . BRAY
others may be precipitated as salts, e. g. the ammonium salt of menthyl D-glucuronide crystallizes from urine on saturation with ammonium sulfate. A list of a number of D-glucuronides which have been obtained in pure form or as crystalline derivatives is given in Table I1 at the end of this article. It will be seen that the groupings which may be metabolically conjugated with D-glucuronic acid are as follows : (i) phenolic hydroxyl group; (ii) aliphatic primary, secondary or tertiary alcoholic groups; (iii) hydroxyl groups in reduced ring systems; (iv) aliphatic and aromatic carboxyl groups. In the absence of evidence to the contrary, it can be assumed that any compound containing the requisite grouping may give rise to a glucuronide, but, as will be seen from Section VI (page 261), whether it in fact forms an appreciable amount of such a conjugate depends on other factors, which may not be at once obvious from a mere inspection of the chemical formula. Free D-glucuronic acid has been found in urine as a consequence of the administration of certain compounds, e. g., aniline, l8 ~henetidine,'~ although they might be expected to form glucuronides in the usual way. It was suggested that the glucuronides actually formed are labile, but their constitution was not determined. Table I1 contains some examples of the same glucuronide being formed after administration of either the parent compound or a metabolic precursor. I n general the metabolic pathways followed by a compound formed in vivo are qualitatively identical with those taken by the compound administered as such, but there are usually quantitative differences, the reasons for which are considered in Section VI (page 260).
111. STRUCTURE OF GLUCURONIDES Glucuronides arising from the conjugation of hydroxyl groups have the properties of true glycosides. The first evidence of their constitution was provided by the synthesis of phenyl D-glucuronide and euxanthic acid by Neuberg and Neimann, referred t o earlier.'O The glucuronic acid moiety of bornyl p-D-glucuronide excreted as a metabolite of borneol by man or rabbit was shown by Pryde and Wilbarnsz0 to have a pyranoid structure. The glucuronide, on treatment with methyl iodide and silver oxide, gave crystalline bornyl 2,3,4-tri-Omethyl-p-D-glucuronide methyl ester. This was converted to a mixture of a! and 0 anomers of methyl tri-0-methyl-D-glucuronides by the action of 0.2 N sulfuric acid in methanol at 100" under pressure. Oxidation of (18) J. N. Smith and R. T. Williams, Biochem. J . , 44, 242 (1949). (19) J. N. Smith and R. T. Williams, Biochem. J . , 44, 250 (1949). (20) J. Pryde and R. T. Williams, Biochem. J . , 27, 1197 (1933).
D-QLUCURONIC ACID I N METABOLISM
255
this derivative by nitric acid gave D-dimethoxysuccinic acid, xylo-triThe methoxyglutaric acid and 2,3,4-tri-O-methy~-~-saccharo-3-lactone. isolation of the last two compounds shows that the D-glucuronic acid in this conjugate has a pyranoid configuration. Sammons and Williamsz1 showed that the fully methylated glucuronide of vanillic acid, on hydrolysis with methanolic hydrochloric acid, gave methyl vanillate and the methyl ester of methyl 2,3,4-tri-O-methyl8-D-glucuronide, showing that the original conjugation involved position 1 of the D-glucuronic acid molecule. There was some controversy before the constitution of benzoyl P-D-glucuronide, the simplest known ester glucuronide, was settled. This conjugate was first isolated by Magnus-Levyzz in 1907 from the urine of sheep dosed with benzoic acid and without evidence was assumed to be l-0-benzoyl D-glucuronide. I n 1926 Quickz3 obtained the same compound as the crystalline free acid from the urine of dogs dosed with benzoic acid. He found that its aqueous solutions underwent a rapid change in rotation in the presence of traces of alkali and attributed this t o mutarotation. On the basis of this observation and the fact that benzoyl glucuronide reacted with hydrocyanic acid with the complete loss of its reducing power, he suggested that the potential aldehydic position 1 was free in the conjugate and that the glucuronide was the 2- or 5-benzoic ester. Pryde and Williamsz4 interpreted the reducing properties of ester glucuronides in terms of the lability of the glycosidic link in alkaline solution and favored Magnus-Levy’s suggested structure. This was also supported on theoretical grounds by the fact that benzoyl D-glucuronide and benzoyl D-glucoside are not exceptions t o the rule that P-Dglucosides and p-D-ghcuronides have similar specific rotations (see Table I, which is based on data cited by Pryde and Williamsz4). They considered the action of cyanide t o be due t o fission of the benzoyl group, followed by mutarotation and the formation of a cyanohydrin of D-glucuronic acid. They isolated benzoic acid from the reaction mixture. QuickzSre-investigated the effect of alkali and hydrocyanic acid on benzoyl glucuronide and found that in 21 hours only 8.9 % of the benzoic acid was liberated, while only 3.9 % of the original reducing power of the glucuronide remained. The problem was resolved by GoebellZ6who prepared the fully (21) (22) (23) (24) (25) (26)
H. G. Sammons and R. T. Williams, Biochem. J., 36, 1175 (1941). A. Magnus-Levy, Bioehem. Z., 6 , 502 (1907). A. J. Quick, J. B i d . Chem., 69, 549 (1926). J. Pryde and R. T. Williams, Bioehem. J., 27, 1210 (1933). A. J. Quick, Biochem. J., 26, 403 (1934). W. F. Goebel, J . Biol. Chem., 122, 649 (1937-8).
256
H . Q. BRAY
acetylated methyl ester of biosynthetic bensoyl glycuronide and showed it to be identical with 1-0-bensoyl-2,3,4-tr~-o-acety~-~-~-glucuron~c acid methyl ester, obtained by condensing l-bromo-1-deoxy-2,3,4-tri-0acetyl-D-glucuronic acid methyl ester with sodium benzoate in boiling acid chloroform. Since l-bromo-1-deoxy-2,3,4-tri-0-acetyl-~-g~ucuronic methyl ester condenses with alcohols to give only p-D-glucuronideslzB* it is likely that benzoic acid also forms a p-D-derivative so that benzoyl TABLE I Specific Rotations,
[&ID,
Derivative
of Corresponding D-Glucosides and DGlucuronides
I
O-DGhcoside [OLID
Benaoyl Phenyl deztro-Bornyl levo-Bornyl levo-Menthyl Phlorogluciuyl W = water; E = ethanol.
and Solvento
-26.8”(W) -71.7(W) -42.4(E) -60 . 1(E) -93.6(E) -74.8(W) r,
I
p-D-Glucuronide [&ID
and sobJenta
-25.3”(W) -82(W) -37b(W) -66.6( W) 104.6(E) -80,8c(W)
-
Na salt. * K salt.
D-glucuronide is as shown in formula I. Goebel suggested that Quick’s observations were not due to mutarotation and postulated that the phenomenon observed was due t o a complex series of reactions initiated by the migration of the bensoyl group, the process being catalyzed by hydroxyl ions. The migration of the bensoyl and acetyl groups of partially acetylated or benzoylated sugar derivatives under alkaline conditions is a well-known phenomenon. 27 (Sammons and Williams28 observed a similar change in rotation with veratroyl glucuronide in the presence of hydrocyanic acid.) Goebel further suggested that the dextrorotatory sodium salt of benzoyl glucuronide isolated by MagnusLevyz2 from urine which had become alkaline on long standing was possibly a derivative of the original glucuronide, which is levorotatory. Structural investigations of glucuronides have so far been confined to very few compounds. It is possible that further work may be undertaken as a result of the recent investigations of Marshzeand of Hardegger and who have shown that glucosides may be readily oxidized to (26a) R. D. Hotchkiss and W. F. Goebel, J . Biol. Chem., 116, 285 (1936). (27) W. W. Pigman and R. M. Goepp, Jr., “Carbohydrate Chemistry,” Academic Press, New York, 1948, p. 166. (28) H. G . Sammons and R. T. Williams, Biochem. J . , 40,223 (1946). . (29) C. A. Marsh, Nature, 168, 602 (1951). (30) E. Hardegger and D. Spita, Helv. Chim. Acia, 33, 337 (1950).
D-GLUCURONIC ACID I N METABOLISM
257
glucuronides by means of nitrogen tetroxide or with platinum catalysts. The smooth catalytic air oxidation of 1,2-0-isopropylidene-cr-~-glucofuranose has been described by Mehltretter and associates (see Chapter V, page 244).
IV. ORIGINOF D-GLUCURONIC ACIDAND MECHANISM OF D-GLUCURONIDE SYNTHESIS The demonstration by Fischer and Piloty9 of the close chemical relationship between D-glucuronic acid and D-glucose gave rise to speculation as to the possibility of a similarly close biological relationship. This problem has not yet been satisfactorily resolved. The earliest theory is due to Schmiedeberg and Meyer18who postulated that D-glucuronic acid was a normal intermediate in the catabolism of D-glucose and was “fixed” by the aglycon. Schiiller31later showed that in phloridzinized dogs, where carbohydrate metabolism was seriously impaired, D-glucuronic acid conjugation could still take place. Fischer and Pilotyg and S ~ n d v i ksuggested ~~ that a n-glucoside was first formed and then oxidized to the corresponding D-glucuronide. Although this is chemically possible (Caillela3MarshlZ9Hardegger and Spitz30), there is no convincing evidence that it occurs in vivo. Hildebrandt34isolated glucuronides from the urine of rabbits which had been injected with certain glucosides, but Pryde and Williams36 showed that injected phenyl 4-D-glucoside gives rise to ethereal sulfate in the rabbit. Thus it is probable that Hildebrandt’s results may be explained by suggesting that the glucosides are first hydrolyzed and the aglycons metabolized as if they themselves had been administered. It is also of interest to note that the glucuronide obtained by SchUller3l as a metabolite of phloridzin still contained a D-glucose residue, so that the D-glucuronic acid residue did not arise by its oxidation. Many investigations were made by early workers using techniques such as starvation and pancreatectomy, but these for the most part gave equivocal results (for summary see WilliamP) , probably because the close interrelation of fat, protein and carbohydrate metabolism was not then fully appreciated and because the analytical methods used were often (31) J. Schuller, 2.B i d , 66, 274 (1911). (32) E. Sundvik, Jahresber. Tierchem., 16, 76 (1886). (33) E. Caille, Thesis, Medicine, Paris (1921); cited by M. A. Leulier, J . pharm. chim., [8] 24, 64 (1936). (34) H. Hildebrandt, Beitr. chem. P h y s k l . Path., 7 , 438 (1906). (35) J. Pryde and R. T. Williams, Biochem. J . , 30, 794 (1936). (36) R. T. Williams, “Detoxication Mechanisms,” Chapman and Hall, London, 1947, p. 188.
258
H. Q. BRAY
inadequate. Later studies of this type, for example those of Q ~ i c k , ~ ’ - ~ ~ using intact dogs, both normal and insulin-treated, of Dziewiatkowski using l frogs, suggested that and Lewis,do using rats and of S ~ h m i d , ~ glycogen, glucogenic amino acids or simpler compounds such as lactic acid were concerned in the formation of D-glucuronic acid. Evidence that small molecules, such as those now known to be intermediates in normal carbohydrate catabolism, might be involved was also obtained by Lipschitz and B ~ e d i n gwho ~ ~ found that the conjugation of borneol, menthol, tribromoethanol and phenol by guineapig liver slices waa an oxidative process, probably involving phosphorylation. It was depressed by adrenaline and stimulated by insulin and by lactate, pyruvate and dihydroxyacetone; glyceraldehyde and hexose diphosphate were ineff ective. Storey43 found that lactate and pyruvate did not stimulate glucuronide formation from o-aminophenol by mouse liver slices and that D-glucuronic acid itself inhibited conjugation. He also obtained evidence that high energy phosphate bonds were involved, and, since conjugation was stimulated by bicarbonate, suggested that carbon dioxide fixation might be concerned in the process. Lipschitz and B ~ e d i n galso ~ ~found that D-glucuronate did not stimulate bornyl glucuronide formation, but De Meio and Arnoltd4obtained indirect evidence that combination of phenol and D-glucuronic acid could be directly brought about by rat liver slices. Levvy and Storey,46however, dispute the validity of De Meio and Arnolt’s evidence. Florkin, Crismer, Duchateau and H o ~ e found t ~ ~ that borneol and D-glucuronic acid could be directly conjugated to a small extent by purified spleen P-glucuronidase in vitro. Martin and StenselJ4’using normal rats, found that dihydroxyacetone, glycerol, lactic acid, succinic acid, malic acid and adenylic acid increased the excretion of D-glucuronic acid and suggested that it is synthesized via dihydroxyacetone phosphate, glycerophosphate and phosphoglyceraldehyde. More recently, isotopic labeling procedures have been applied t o the (37) A. J. Quick, J . Biol. Chem., 70, 59 (1926). (38) A. J. Quick, J . Biol. Chem., 70, 397 (1926). (39) A. J. Quick, J . Biol. Chem., 98, 537 (1932). (40) D. D.Dziewiatkowski and H. B. Lewis, J . Biol. Chem., 163, 49 (1944). (41) F. Schmid, Compt. rend. soc. biol., 123, 223 (1936). (42) W. L. Lipschitz and E. Bueding, J . Biol. Chem., 129, 333 (1939). (43) I. D.E.Storey, Biochem. J . , 47, 212 (1950). (44) R. H.De Meio and R. I. Amolt, J . Biol. Chem., 166, 677 (1944). (45) G.A. L e w y and I. D. E. Storey, Biochem. J . , 44, 295 (1949). (46) M.Florkin, R. Crismer, G. Duchateau and R. Houet, Enzymologia, 10, 220 (1941-2). (47) G.J. Martin and W. Stenzel, Arch. Biochem., 3, 325 (1944).
D-GLUCURONIC ACID I N METABOLISM
259
problem. Mosbach and King,48using D-glucose labeled in all positions with CI4, obtained evidence that D-glucuronic acid excreted by guineapigs as conjugates of borneol was formed without rupture of the D-glucose carbon chain, or in such a way as to involve recombination of fragments without detectable dilution effect. Packham and Butler49found that Cl4-labeled lactate, pyruvate and D-glucose were incorporated to equal extents into P-naphthyl D-glucuronide by rats. Labeled D-glucuronate was also utilized, but when given intraperitoneally it was twenty times as effective as when administered orally. Eisenberg and Gurin,6O investigating the menthyl D-glucuronide isolated from the urine of menthol-treated rabbits which had also received ~-glucose-l-Cl4, suggested that the precursor of D-glucuronic acid is D-glucose or an equivalent six-carbon compound. DoerschukKon has studied the role of glyceroll-C14 in glucuronide formation from borneol in guineapigs and has concluded that a three-carbon compound of the same type as glycerol may be involved. Thus it seems certain that glucuronide formation is closely related to carbohydrate metabolism, but the details of the mechanism are, as yet, unknown. The important points which have to be elucidated refer to the immediate precursor or precursors of D-glucuronic acid and to the nature of the conjugation process, for example, whether D-glucuronic acid is built up on the aglycon molecule or whether direct union of the acid with the aglycon can occur. The suggestion of Miller and his coworkersK1J2that D-glucuronic acid for conjugation is derived from mucin and is not directly concerned with major metabolic processes does not appear to have received much support. V. SITE OF D-GLUCURONIDE FORMATION Little work has been done to determine the site of D-glucuronide formation in vivo, but the evidence available suggests that the liver is mainly responsible. Hemingway, Pryde and Williams,63in experiments with a perfused dog lung-liver-kidney preparation concluded that the liver was the main site of D-glucuronic acid conjugation. Schrnid4l reached a similar conclusion for the frog. (48) E. H. Mosbach and C. G. King, J. Biol. Chem., 186, 491 (1950). (49) Marian A. Packham and G. C. Butler, J. Biol. Chem., 194,349 (1952). (50) F. Eisenberg, Jr., and S. Gurin, J. Biol. Chem., 196, 317 (1952). (50a) A. P. Doerschuk, J. Biol. Chem., 196, 855 (1952). (51) C. 0.Miller, F. G. Brazda and E. C. Elliott, Proc. SOC.Ezptl. Biol. Med., SO, 633 (1932-3). (52) C. 0. Miller and J . A. Conner, Proc. SOC.E x p t l . Biol. Med., 30, 630 (1932-3). (53) A. Hemingway, J. Pryde and R. T. Williams, Biochern. J . 28, 136 (1934).
260
I%. G. BRAY
In in vitro experiments, Lipschitz and B ~ e d i n found g ~ ~ that the liver, and, to a much lesser extent, the kidney were the only tissues of the rabbit, rat and guineapig which could conjugate various hydroxy compounds with D-glucuronic acid. L e w y and S t ~ r e yfound ~ ~ ,that ~ ~mouse liver slices conjugate o-aminophenol with D-glucuronic acid, but that kidney was much less active and spleen inactive.
VI. KINETICSOF D-GLUCURONIDE FORMATION A series of investigations of the metabolism of foreign organic compounds in the intact rabbit recently r e p ~ r t e d have ~~-~ given ~ information about the kinetics of glucuronic acid conjugation in vivo. Treatment by the usual graphical methods of physical chemistry of the excretion curves obtained for the elimination by the rabbit of the metabolites of benzoic acid and certain of its precursors (benzamide, toluene, benzyl alcohol and benzaldehyde) and of various phenol and phenol precursors suggests that, to a first approximation, the metabolic processes involved follow simple reaction kinetics, Conjugation of benzoic acid or of phenols with D-glucuronic acid, hydroxylation, oxidation of methyl, hydroxymethyl and aldehyde groups and hydrolysis of amides followed first-order kinetics with respect t o the administered compound (i. e., the formation of the metabolite was proportional t o the body level of the administered compound), while conjugation of benzoic acid with glycine and of phenols with sulfuric acid followed first-order reaction kinetics below a certain body level and zero-order kinetics (i. e., the metabolite was formed at a uniform rate) above this level. Considering the rabbit and its urine as a closed chemical system, a mathematical model was derived to express such combinations of first- and zeroorder processes as occur in the metabolism of the compounds in question. The amount of glucuronide arising from the conjugation of a phenol or benzoic acid is given by G = B - v,T - v,/k, where B is the dose level of the acid or phenol, v, the zero-order velocity constant of the second conjugation process (i. e., with glycine or sulfuric Ic,, these being the first-order velocity constants for acid) and k , = k ,
+
(54) H. G. Bray, W. V. Thorpe and K. White, Biochem. J., 48, 88 (1951). (55) H. G. Bray, Brenda G. Humphris, W. V. Thorpe, K. White and P. B. Wood, Biochem. J., 62, 412 (1962). (56) H. G. Bray, Brenda G. Humphris, W. V. Thorpe, K. White and P. B. Wood, Biochem. J., 62, 416 (1952). (57) H. G. Bray, Brenda G. Humphris, W. V. Thorpe, K. White and P. B. Wood, Biochem. J., 62, 419 (1952). (58) H. G. Bray, W. V. Thorpe and K. White, Biochem. J., 62, 423 (1952).
D-QLUCURONIC ACID IN METABOLISM
26 1
the first (i. e., glucuronide formation) and second conjugation processes. T is the time after dosage a t which the critical body level is reached. The amount of glucuronide arising from administration of a precursor (at dose level A ) which is converted to the acid or phenol by a process having a first-order velocity constant k b is given by G =A
- v,T
- (kl/km)(Ae+"
+ v*/k*).
The percentages of compounds excreted conjugated with glucuronic acid therefore depend on the values of constants typical of the compound itself, on the dose level and on the value of v,, which appears to be a property of the organism that is relatively constant for a given species. If the values of the "velocity constants" obtained by graphical treatment of excretion curves were substituted in the above expressions (T may be calculated), the values obtained for glucuronide excretion (and conversely for that of sulfuric acid or glycine conjugate, since the two processes are complementary) agreed well with those observed in actual experiments. It cannot be decided, on existing evidence, what the exact nature of the velocity constants determined is, i. e., whether they are true chemical reaction rate constants, or concern some phase of an enzymic or diffusion process, but application of the expressions derived makes possible an interpretation of various observations such as the variation in glucuronide excretion with varying dose level, the differences in the amounts of metabolites formed by different species from the same administered compound and the differences in the amounts of metabolites excreted after administration of a compound and of its precursor. The results of experiments concerning the relation between the values of the constants and the chemical nature of various compounds were also rep0rted.~'*~7The value of k, for para substituted phenols appeared t o depend on the size of the substituent grouping rather than on its electronic nature, while the value of k, was not simply related to either. Further studies of this type may elucidate the significance of the constants derived and may throw light on the mechanism of the processes involved. VII. ENZYMES AND D-GLUCURONIDE FORMATION
It has been known since 1905 that ether glucuronides, as glycosides, may be hydrolyzed by a variety of enzyme preparations, e. g., emulsin hydrolyzes euxanthic acid, l o phenyl D-glucuronidelo and camphor-Dglucuronic r t ~ i d . " ~ -The 6 ~ enzyme responsible, p-glucuronidase, appears (69) J. Hiimiiliiinen, Skand. Arch. Physiol., as, 297 (1910). (00) M . Ishidate, J . Pharm. SOC. Japan., 49, 336 (1929).
262
H. Q. BRAY
to be distinct from p-glucosidase.61 Serat2 observed that chloroformwater extracts of liver, spleen and kidney of ox, rabbit and dog hydrolyzed the D-glucuronides of orcinol and phloroglucinol. Hofmannea showed that P-naphthyl glucuronide was hydrolyzed by rabbit and horse liver and kidney. O ~ h i m ashowed ~ ~ ~ that ~ ~ spleen and various endocrine organs were better sources of p-glucuronidase than were liver and kidney; tissues of carnivores were richer sources than those of herbivores. A glucuronide-hydrolyzing enzyme has also been found in bacteria.8e-6s Many accounts of active p-glucuronidase preparations have been given, e. g., by M a s a r n ~ n eFishman,To ,~~ Mills and his c o ~ o r k e r s , Graham,’* ~~J~ Le w y and his c ~ w o r k e r s . ~ ~ItJ ~seems probable that there may be several closely related enzymes (see e. g., reference 72). At the present time there is lively interest in the metabolic function of p-glucuronidase, stimulated by the observation of FishmanT6 that it hydrolyzes oestriol glucuronide more readily than the glucuronides of borneol or menthol. In recent review^^^^^' this worker discusses the hypothesis that the enzyme may be related to oestrogenic activity. He foundTs that administration of non-oestrogenic substances, such as borneol or menthol, to mice increased the 8-glucuronidase activity of liver, kidney and spleen, but not that of uterus, testis, ovary or vagina. In contrast, the uterine enzyme in ovariectomized mice was increased (61) W. W. Pigman and R. M. Goepp, Jr., “Chemistry of the Carbohydrates,” Academic Press, New York, 1948, p. 490. (62) Y. Sera, 2.phpiol. Chem., 02, 261 (1914). (63) E. Hofmann, Biochem. Z., 281, 438 (1935). (64) G. Oshima, J . Biochem. (Japan), 20, 361 (1934). (65) G. Oshima, J . Biochem. (Japan), 23, 305 (1936). (66) Mary Barber, B. W. L. Brooksbank and G. A. D. Haslewood, Nature, 182, 701 (1948). (67) H. J. Buehler, P. A. Katzman, P. P. Doisy and E. A. Doisy, PTOC.Soc. Erptl. Biol. Med., 72, 297 (1949). (68) Evelyn E. B. Smith and G. T. Mills,Biochem. J., 47, xlix (1950). (69) H. Masamune, J . Biochem. (Japan), 10, 353 (1934). (70) W. H. Fishman, J . B i d . Chem., 127, 367 (1939). (71) G. T. Mills, Biochem. J., 43, 125 (1948). (72) G. T. Mills and J. Paul, Biochem. J . , 44, xxxiv (1949). (73) A. F. Graham, Biochem. J., 40, 603 (1946). (74) Lynda M. H. Kerr and G. A. Lewy, Biochem. J., 48, 209 (1951). (75) P. G. Walker and G . A. Levvy, Biochem. J., 40, 620 (1951). (76) W. H. Fishman, J . Biol. Chem., 1S1, 225 (1939). (77) W. H. Fishman, “The Enzymes,” edited by J. B. Sumner and K. MyrbLick, Academic Press, New York, Vol. 11, Pt. 1, 1950, p. 636. (78) W. H. Fishman, J . Biol. Chem., 136, 229 (1940).
D-GLUCURONIC
ACID I N METABOLISM
263
greatly by the administration of oestrogens, such as oestrone and oestradiol, while the liver enzyme was virtually ~ n c h a n g e d . ’ ~In considering t!hese results it was assumed that the hydrolytic and synthetic enzymes were identical and it was suggested that the increase in activity is a protective mechanism evoked to control hyperaction of the oestrogen or t o facilitate the metabolism of a foreign organic compound. Its action under the conditions of the experiments performed was compared to the enzymic adaptation frequently observed in bacteria, but studied comparatively rarely in animals. This idea of a reversible glucuronide synthesis is in accord with the observation of Florkin and his coworker^,^^ referred to earlier, and with the results of other workers, also mentioned above, which showed that D-glucuronic acid itself could stimulate glucuronide synthesis, but is opposed t o the findings of Lipschitz and R ~ e d i n gand ~ ~of Storey.43 Levvy and his coworkers, on the basis of an intensive investigation, concluded that two separate enzyme systems are involved. It was foundsothat the increase in the hydrolytic activity of various tissues was related to cell proliferation resulting from the physiological action of oestrogens or due t o repair following the toxic action of foreign organic compounds. An increase in hydrolytic activity was produced by the administration of compounds which could not form glucuronides, e. g., yellow phosphorus, uranyl acetate, mercuric nitrate. Mills and his coworkerss1 found, however, that in the growing rat and in liver regenerating after hepatectomy there was no relation between the rate of cell proliferation and p-glucuronidase activity. Levvy also obtained direct evidence for the existence of both hydrolytic and synthetic enzyme sy~tems.~~-*4 The hydrolytic enzyme was found in almost all mouse tissues, while the synthetic system was confined almost entirely to liver. D-Saccharic acid inhibited the hydrolytic enzyme, but had only a slight effect on the synthetic process. The synthetic activity of liver did not vary with the degree of cell proliferation. (79) W. H. Fishman and Lillian W. Fishman, J . Biol. Chem., 162, 487 (1944). (80) G. A. Levvy, Lynda M. H. Kerr and J. C. Campbell, Biochem.J., 42, 462 (1948). (81) G. T. Mills, Evelyn E. B. Smith, Beatrice Stary and I. Leslie, Biochem. J . , 47, xlviii (1951). (82) M. C. Karunairatnam, Lynda M. H. Kerr and G. A. Levvy, Biochem. J . , 46, 496 (1949). (83) M. C. Karunairatnam and G. A. Levvy, Biochem. J., 44,599 (1949). (84) M. C. Karunairatnam, Lynda M. H. Kerr and G. A. Lewy, Biochem. J., 44, xxx (1949).
Subatitwnt
None
pNRCOCHi
TABLE I1 Biosynthetic Glueuronides and Their Derivatives" Aromatic Ether Glucuronides Phenol and Its Derivatim Compound Melting adminiahredb Species" Derivatived . Point, "C. P 161-2(d.) R A 161-2(d.) P R A. 2HaO 207-8(d.) P R A. Benzylamine salt 153 P R B 116 P R C or D 256 (d ) benzene 158 R E A 193(d.) phinophenol 195-7 Acetadide R A. Benzylamine salt
pCHtNHCOCHt WI-O--COCH~ ~ ~ C O C H I pCHO o-NH*
C
205
-90.5"(W) -78.5(W) -62.3(W) -63 f I(M) 0.5(C) -33 -32.5(E) -70 k 5(M) -33 f 1(C) -63.9(W) -63.8(W) -64.1(W) -59(W) -59(W) -6O(W) -22.1(C) -22.4(C)
C F C C C
205-7
-23.5(C)
224(d.)
-15.1(A) -29.05(A) -24.5(A) -21.8(A)
:{
Aniline Phenetidine Phenacetin Acetanilide Aniline Phenetidine Acetanilide
R
R
Resorcinol Quinol
P P
.
R
R R R R R
R R R
E
Refer[a]D ( S O l w @ )
do. do. do.
C
A. 2,4-dinitrophenylhydrazone A A A. Benzylamine aalt
195-8 195-8 195-7 2430-205
174 113-4 151 166
d. 300 d. from 230 204-5
*
- 7 6 . 1(HCI) --87(W) -61.3(W)
en4233
85
85 85 86 86 86
:? 87 W
18 19 88 87 18 19 87 89 90 90 89
87, 91 92 87
2
m-NH2
P
PNHZ
P P Aniline P P P
pN=N-CaH,
P
:{
R R R R R R
R
0-Br
P
R
mBr
P
R
P-Br
P
R
o-CONHZ m-CONHz
P P
R R
pCONHx
P
R
pCOOH
P
D
0-c1
P
m-C1
P
R
PC1
P P
R R
P P or chlorobenzene
:1 R R
A A A. A. A. A A. A. A
HzO Hs0
HzO Benzylamine salt l%H*O
D. Hz0
CP
2Hs0
A A
{ 2. Ba salt
A (Diglucuronide)
C D. ?6HzO E A. Hz0
B C D D E E
{:
d. 300 d. from 220 213(d.) 215-6 215-6 218 211-2 164 164-5 141-3 202-5 (d. ) 121 215-8(d.) 157 157-8 255-265 (d.) 175-6(d.) 163-4(d.) 212(d.) 299-300(d.) c. 200(d.) 151-2 202 126 211 154 151 157 151-2 245-6 244-6 159 157-9
-94(HC1)
-lOo(W)
-82.7(HCl) -82.7(HCl) --83.4(Hzso4) -93(W) -62.7(HCl) -88(E) -64.6(C) -64.3(W) -33.l(C) -57(W) -68.2(W) -28(C) -61(W) -84(W) -67(W) -93(W) -78(W) -15 to (W) - 16 -65(C) -69.5(M) -45.3(E) -84.7(M) -13.3(E) -82(W) -WW) -32.9(C) -85.6(M) -84.9(M) -10.7(E) - lO(E)
91 92 91 87 18 92 87 93 94 95 95 95 95 95 95 95 96 96 16 16 97
95 98 98 98 98 99 95 95 98 100 98 100
7 g? 2
3
g
3
6 U
2
3
i
0
E
g
TABLEI I1 (Continued) Substituent
Compound administer&
Specie@
P
R
o-CN
P
m-CN
P
F C {D. ISHzO
P Phenetole
D
.1:
D Hzo A
P R R
P
PI o-OCHS m-OCHt
Catechol Resorcinol Quinol
P
Derivatived
:{
D D
h3
Melting Point, "C. 175-6 151-2 195 156-7 207(d.) 140(d.) 130-135 21M(d.) 146 151-2 208-2 10(d.) 135 224(d.) 213 227-230
161-2 154 c. 158 167-8 107 216-7 144 21&211 127 238-240 143-4 131 200-202
[a]D (soZuente)
--20.8(C) -71(C) -78(E) -37(C) -63(W) -92(W) -42(C) -72(W) -63
-44.7(C) -71(M) -33(C) -77(M) -81.6(M) -85.7(M) -59(W) -63.3(C) -68.8(W) -68(E) -25.8(C) -49.3(E)
-WM) -61.4(C) -75.5(M) - 12.9(E) -26.3(C) -81.7(M) -28.7(C) -46.7(C) -71.2(E)
Referencea 95 101 101 101 101 101 101 101 102,103 95 95 95 95 95 95 95 95 95 95 95 104 95 95 95 95 95 95 95 95
95
Q, Q,
3 Q
; 4
P
P
i.
{
R *NOS
P P P
P
pCsHs
pOCsHs pSOoNHz pSOiN (CHa)z pNHCONHz
R
~with p D
(0{g.
?(H20
{g B C E
P
Diphenyl ether P p H ydroxybenzencsulf onamide N-Phenylurea “Elbon“ (pUreidophenyl cinmate)
R R R
A. Benzylamiie salt A A. Basalt H
R R
A. K salt A. K salt
93-4 222-4 147(d.)
~
140 257-9 172 173-5 195-6 159-160 206 146 210 c. 123 132 192-6 183 189 192-3 170-1 277(d.) 207-210 205(d.) 174 154-5 257(d.) 231(d.)
-25. 6(C) - 68.7(E) -71.8(W) -34.5
~
-36(C) -76.6(M) +18.5(C) -63.8(E) +31.2(C) -42.6 (C) -91(M) -51(C) -96(M) C. -63(E) -85.3 (C) -WE) -85.3(E) -90. 6(NaOH) -81.8(E) -30.3 (C) -14(C) -69.7(NaOH) -70(W) -5O(W) -42.3 (E) -52.3(W) -7O.l(W) - 74.99 (W)
.
95 95 105 106 95 95 107 107 107 107 107 107 107 95 95 95 95 108
95 95 108 136 109 109 110 111
~ 7
3 g
3 5 u
q 0
5g
Kl
TABLEI1 (Continued) Substilueni
pHydantoylmethy1
Compound administet& l',thyn"' (pUreidopheny1furylacrylate) do. Tyrosinehydantoin
Species"
R D R
Derivatived A. K d t A. K salt A. K salt
Melting Point, "C. 243(d.)
231(d.)
ReferblD
hie)
m
emZ3
-67.8(W)
112
-59.3(W) -98(W)
112 115
-67. 7(Na2COa)
91 91 100 100 116 117 17 17 17 17 17 17 118
Disubstitutd Phenols
P P PChlorocatechol
R
4-Cl-3-OCHs 3-Cl4OCHt 2,3-Di-CHI 2,4-Di-CH1 2,5-Di-CHa 2,6-Di-CHa 3,4-Di-CHs 3,5-Di-CH3 4-CH&O-3-OH
4-Chlororesorcinol Chloroquinol 2,3-Xylen-1-01 2,4-Xylen-l-o1 2,5-Xylen-l-o1 2,6-Xylen-l-ol 3,PXylen-l-ol 3,5-Xylen-l-ol Resacetophenone
R R R R R
3,5-Di-OH 3-OH-5-CHa SOH.PC&IIN=N
Phloroglucinol Orcinol Benzeneaeoresorcinol
R R
R R R R R R R R R
R
%OCH&CHO
R Vanillic acid
R
A. A. D. D. D. D. A. A. A. A A. A. A. A. A.
2?4HaO 2j4H2O 2H20 H2O HzO H20 34H20 2HzO ?$HzO
%HzO HzO HzO HZO K salt A. Bas& A. H20 h A. Snaphthylhydrazone A. 2,4-dinitrophenylhydraaone G
150(d.) d. from 140 218 218 214-5 219-220 156 78 154 185 142 165-170 175-6 (d.) 170(d.)
- 76. 9(Na,COJ)
- 113.5(A) -96.15(A) -103.3(A) -86.6(A) -74.2(W)
-138(W)
-97(W) -5O(W) - lOO(W) -78(W) -99(W)
119
198 189-190 179 200(d.)
-80.8 -73.6 - 114(E)
120 121 93
-78.9(M) -68.2(D)
21 21
137
-86.05(C)
21
94
Q
$
Tri- and Tetra-substitutedPhenols Glueuronide of Phloretin Phloridzin (2,4,6Trihydroxy-3(phydroxypheny1)propiophenone) Phloridzin (Phloretin-2 glucoside) 2,4--Diehlorothymol Thymol
Stilboestrol
’
Hexoestrol
P
P
P
R
A
R
A
M A D A R A Miseellaneoua Phenolic Compounds R A. 2Ht0 R A. 2Hz0 R A R A. Benzylaminesalt R A. 3HzO R A. 3H20
d. from 110
-68.7(W)
31
-102.3(W)
31
125-6 118-9 118
-66.2 -66.5
122 123 124
174-6 179 175 223(d.) 183-4(d.) 1%9(d.) 222
-51.6( -57.6) (E) -56.5(E) -56.6(E) -55.3(A) -66.3(NaOH) -73.4(NaOH) -48.7(HCl/E)
113 10s 114 10s 10s 113 108
175-183(d.) 181-3(d.) 223(d.)
-41.5( -47.2) (E)
113 108
{ t.pToluidine salt
198-9 1540(d.) 202-3
-85(E)
{t.pToluidine salt
149-150 184-6 100 150 151
6
2 g2 d
9
8 g
Dienoestrol 1-Naphthol
P P Naphthalene
%Naphthol
P
R R
Rt R R Rt R R R
A A. HzO
A A
A. Hydrate A A
-45. S(Na0H) -35.4(NaOH)
-89.3 -97(E)
-90.65 -85
-100.8
2
108
0
125 125 126 127 125 1.25 126 127 128
s
E
h3
TABLE I1 (Continued) Substituent Z Hydroxyquinoline (Carbostyril) 8-H ydrox yquinoline
Compound administeredb
Species'
{t.
P
Ksalt A. K salt
3-Hydroxycoumarin Phenolphthalein
"Chinosol" (K salt of ethereal sulfate of 8hydroxyquinoline) or P P P
M R
Indoxyl
Indole
D
Euxanthone 2- (3-Hydroxypheny1)benzoxazole ~(?)-HY&oxYbenzoxazolone
P ZPhenylbenzoxazole
Derivatived
R
A 207 A. Cinchonidinesalt: 19O(d.) EtOH Double Ba salt of A and indoxyl sulfate A 154-160
R
A. HzO
A. 2H20 A. Complex of Bs salt Antipyrine (?)-HydroXywith BaClr antipyrine (A. Basalt Aliphatic Ether DClueuronides Methanol P R C 0-Nitrobeneyl alcohol o-Nitrotoluene D Complex of A with urea, 2!6H20 P R C Ethanol Phenyl methyl earbinol Acetophenone or ethylR A. K salt, HzO benzene 2,2,2-Trichloroethanol Chloral hydrate R A R A. Na salt P R A 2,2,2Tribromoethanol Phenyl ethyl carbinol Propiophenone R A. Ksalt R A. Cd salt Phenyl n-piopyl carbinol Propyi beneyl ketone Benzyl iso-propyl carbinol Isopropyl benzyl ketone R A. K salt Benzoxazolone
Melting Point, "C. d. 250-2 d. 270-2
R
[ a ](soluent') ~
-85.17(W) -83.8
129 129 130
-72.05 -64.5
131 132
-34
133
- 108
134 92
202 193(d.)
15&1
-79(W) -44.4(W)
92 135
-55.56(W)
135
-30.3(C)
147 7
-32.8(C) - 124(W)
137 138
-65.2(W) -7Q.I(W) -126(W) -108.7(W) -54.9(W)
139 140 141 138 138 138
148-9 144 142 145.5
References
t3 3
x P
$
-28.5(W)
h t B u t y l alcohol 1,l-Dimethyl butyl carbinol t e r t h y l alcohol
P
R
A. K salt
P P
R
C A. K salt
104
Di-n-propyl carbinol
P
103
Diphenylacetic acid
P
R C Ester DGlucuronides A
Bencoic acid
P
R
(I i
Strychnine
-34.14(W)
180-5(d.) 1-5 162 170-172 183
C pAminobenzoic acid
P
J3
pHydroxybenzoic acid pDimethylaminobenaoic acid phlethoxybenzoic acid (Anisic acid)
P
D R
Veratric acid (3,4Dimethoxybenmic acid) l,%Dihydroxy1.2-Dihydro-anthracene Pregnane-3 (a),20-diol
pDimethylaminobenzaldehyde Anisaldehyde
R
(%
Complex of A with parcompound A (Diglucuronide) A C
P or veratraldehyde
145 190-1 208-210(d.) 193(d.) c. 200(d.)
d. from 198
I:
143 140 142 143
144 26 2 2 g 23 r
-25.2(W) 25.3(W) -16.9(C) - 16.3(M) 12(W) -5.5(W)
26 26 145 145
-15 to 16(W) -12(HCI)
97 146
-
169-170
-20.5(C) - 13.l(W)
167 144.5
-2.5(M) -9.9(W) -31.3(M)
158
Ether DGlucuronides of Compounds with Reduced Rings 197 R A Rt A 199-200 178-180 178-180(d.) Human pregnancy urine A. HIO 179-180 A. Nasalt m-271 A. Na salt hydrate 283.5-284.5 Anthracene
-34.75(W) -28.S(W)
142
- 197(D) - 1l4(D) -5m
242
148 148 150 151 149 149 151
3 g g ~
n;u 2
~
3
hl
Tmm I1 (Continued) Compovnd
Substihcent Oeatriol
adminiatwe@ do.
P
&Borneo1
Sp&?@
R
Deridived A. Nasalt
11. {t.
A. Hydrate
Melting Point, "C.
-28.2(-21.0)(W) -37.02(W)
184-5 94-5
-36.67(W) -69.030
Nasalt
2-Borneo1
P
A. Hydrate Nasalt
162-3 96-7
-66.83(W)
94-5
P
&Borneo1 dGIsoborneol
P
Camphenilol
P
BHydroxycamphor
R
R
Camphor
A. Strychninesalt
P
Z-Fenchyl alcohol
Ghfenchyl alcohol 2(3?)-Hydroxycineole
Cineole
pMenthan-3,S-diol
Citron-
A A
P
R R R
A A. NHIsalt 'A. K salt, HsO A. Nasslt A. Strychnine salt, 3H20 A A. Brucinesalt A. HtO
163-5 104-6 162-3 150-3 138(d.) 190-5 124-6
Refer-
'
-42.98(W) -47.93(W) -42.62(W)
- 63.09(W) -23.08 -41.06 -63.W(A) -55.94(W) -54.45(W) -53.79(W) -81,02(W)
-12.7(E) -8.l(NaOH)
or P
A. pBromophenacy1 ester, %MeOH B C
152 153 153 155 153 153 155 153 156 153 l53
x
157
9
153 }158,159
)
157
220-2 140-5 186-91 192(193)
196.5 193-4 171-2
8
[ a ] (sduen@ ~
-lo@) --2o(C)
157 160 161 161 161 161 161
* 4
c-
P
1-Menthol &Isomentho1
A. HsO A. NH,salt
P
d-Menthol
lMRZ0
d-Isomenthone
R
{i
120-2 200-202 87-8 110 124-5 126
A. NHdsalt
145(140)
P
d-Neomenthol
or l-Menthone
P
Sabin01
A. NHI salt, HsO A. N H ~ s a l t
R
{t-S-chninedt A. Strychnine mlt,
P
a-Santenol
82.3 196-7 160-1 173-4
-104.1 -42.9(E) -43.2(E) -41.4(W) - 15(- 14.6)(E) -lO(Na0H) -5.9(W) -6.9(W) -39.60(E) -56.6(W)
-52.67(W)
162 162 163 164 165 151: 154
157 157
-
U
2! 157
The detaila of isolation of the glucumnidea and their derivatives, c. u., whether they were obtained directly from urine under the appropriate conditions or prepared from the isolated glucuronide, have heen ignored. All glucuronidea are mono-@luaumnideau n l e otherwise stat8d. P = Parent compound adminisR = Rabbit, D = dog, M man. S = sheep. R* = rat. A = Free gluaumnide. B = methyl ester of glucuronide. C = methyl ester of 2.3.4-tritered. O-acetyl-wglucuronide, D = amide of glucuronide, E = amide of 2.3,~tri-O-acetyl-pglucuronide,F = 2,3,4-tn-O-acetyl-~-glucuronide,0 = methyl ester of 2,3,4-tri-O-methyl-~glucuro~de,H = amide of 2,3,4-tri-0-methyl-ngIucuronide. ' W = Water, E = ethanol, M = methanol, A acetone. C = chloroform, D dioxane.
-
r
165
-55.32(W) -52.48(W) 0
g
is
ki0 E
274
H. 0. BRAY
(References to Table 11) (85) G. A. Garton, D. Robinson and R. T. Williams, Biochem. J., 48, 65 (1949). (86) D. V. Parke and R. T. Williams, Biochem. J., 48, 621 (1951). (87) J. N. Smith and R. T. Williams, Biochem. J., 42, 538 (1948). (88) J. N. Smith and R.T. Williams, Biochem. J., 44,239 (1949). (89) R. L. Hartles and R. T. Williams, Biochem. J., 43, 296 (1948). (90) G. A. Garton and R. T. Williams, Biochem. J., 44, 234 (1949). (91) R. T. Williams, Biochem. J., 37, 329 (1943). (92) H. G. Bray, R. C. Clowes and W. V. Thorpe, Biochem. J., 61, 70 (1952). (93) J. N. Smith and R. T. Williams, Biochem. J., 48, 546 (1951). (94) W. Salant and R. Bergis, J . B i d . Chem., 27, 403 (1916). (95) I. A. Kamil, J. N. Smith and R. T. Williams, Biochem. J . , 60, 235 (1951). (96) H. G. Bray, Brenda E. Ryman and W. V. Thorpe, Biochem. J., 49,561 (1948). (97) A. J. Quick, J . B i d . Chem., 97, 403 (1932). (98) B. Spencer and R. T. Williams, Biochem. J., 47, 279 (1950). (99) B. Spencer and R. T. Williams, Biochem. J., 48, 537 (1951). (100) J. N. Smith, B. Spencer and R. T. Williams, Biochem. J . , 47, 284 (1950). (101) J. N. Smith, Biochem. J., 46, 638 (1949). (102) A. Kossel, 2.physiol. Chem., 4, 296 (1880). (103) V. Lehmann, 2.physiol. Chem., 13, 181 (1889). (104) G. A. Garton and R. T. Williams, Biochem. J., 43, 206 (1948). (105) H. G. Bray, W. V. Thorpe and K. White, Biochem. J., 46, 275 (1950). (106) C. Neuberg and E. Kretschmer, Biochem. Z.,36, 15 (1911). (107) D. Robinson, J. N. Smith and R. T. Williams, Biochem. J., 60, 221 (1951). (108) K. 8.Dodgson, G. A. Garton, A. L. Stubbs and R. T. Williams, Biochem. J . , 42, 357 (1948). (109) H. G. Sammons, Jean Shelswell and R. T. Williams, Biochem. J . , 36, 557 (1941). (110) H. G. Bray, H. J. Lake and W. V. Thorpe, Biochem. J . , 44, 136 (1948). (111) K. Morinaka, 2. physiol. Chem., 124, 247 (1922). (112) S. Tsunoo, J. Biochem. (Japan), 22, 409 (1935). (113) S. A. Simpson and A. E. Wilder Smith, Biochem. J . , 42, 258 (1948). (114) A. Masur and E. Shorr, J . Biol. Chem., 144, 283 (1942). (115) K. Ichihara and 5. Tamura, Z . physiol. Chem., 214, 33 (1933). (116) K. S. Dodgson and R. T. Williams, Biochem. J., 46, 381 (1949). (117) K. S. Dodgson, J. N. Smith and R. T. Williams, Biochem. J . , 46, 124 (1950). (118) K. S. Dodgson, Biochem. J . , 47, xi (1950). (119) M. Nencki, Ber., 27, 2732 (1894). (120) Y. Sera, 2.physio2. Chem., 90, 258 (1914). (121) Y. Sera, 2. physiol. Chem., 88, 460 (1913). (122) F. Blum, Z. physiol. Chem., 16, 514 (1892). (123) K. Katsuyama and S. Hate, Ber., 91, 2583 (1898). (124) K. Takao, 2. physiol. Chem., 191,304 (1923). (125) M. Berenbom and L. Young, Biochem. J., 49, 165 (1951). (126) M. Lesnik and M. Nencki, Ber., 19, 1534 (1886). (127) S. Umesawa and H. Masamune, J . Biochem. (Japan), 28, 487 (1938). (128) F. Bergmann, Biochem. Z., 267, 296 (1933). (129) B. von Fennyvessy, 2. physiol. Chem., 30, 552 (1900). (130) C. Brahm, 2.physiol. Chem., 28, 439 (1899). (131) L. Flatow, Z. physiol. Chem., 84, 367 (1910).
D-C+LUCURONIC ACID IN METABOLISM
(132) (133) (134) (135) (136) (1953). (137) (138) (139) (140) (141) (142) (143) (144) (145)
275
(References to Table 11-continued) A. A. di Somma, J. Biol. Chem., lSS, 277 (1940). C. Neuberg and E. Schwenk, Biochem. Z., 79, 383 (1917). S. v. Kostanecki, Ber., 19, 2918 (1886). D. Lawrow, Z. physiol. Chem., 32, 110 (1901). H. G. Bray, W. V. Thorpe and Marie R. Wasdell, Biochem. J., 64, 547
I. A. Kamil, J. N. Smith and R. T. Williams, Biochem. J., 61, xxxii (1952). H, Thierfelder and K. Daiber, Z. physiol. Chem., 1S0, 380 (1923). E. Kulz, Arch. ges. Physiol. (Pflilgen), 28, 506 (1882). H. Thierfelder, Z. physiol. Chem., 10, 163 (1886). C. Endoh, Biochem. Z., 162, 276 (1924). H. Thierfelder and J. von Mering, Z. physiol. Chent., 9, 511 (1885). I. A. Kamil, J. N. Smith and R. T. Williams, Biochem. J.,49, xxxviii (1951) S. R. Miriam, J. T. Wolf and C. P. Sherwin, J. B i d . Chem., 71, 249 (1927). H. G. Bray, H. J. Lake, F. C. Neale, W. V. Thorpe and P. B. Wood, Biochem. J., 43, 434 (1948). (146) M. JaffB, Z. physiol. Chem., 4Sp374 (1905). (147) I. A. Kamil, J. N. Smith and R. T. Williams, Biochem. J., 64, 390 (1953). (148) E. Boyland and A. A. Levi, Biochem. J., SO, 728 (1936). (149) Eleanor M. Venning and J. S. L. Browne, Proc. SOC.Exptl. Biol. Med., 34, 792 (1930). (150) R. D. H. Heard, M. M. Hoffman andG. E. Mack, J . Biol. Chem., 166,607 (1944). (151) Elisabeth S. Sutherland and G. F. Marrian, Biochem. J . , 41, 193 (1947). (152) S. L. Cohen, G. F. Marrian and A. D. Odell, Biochem. J., SO, 2250 (1936). (153) J. Hamalainen, Skand. Arch. Phyaiol., 23, 86, 297 (1910). (154) R. T. Williams, Biochem. J., S2, 1849 (1938). (155) A. Magnus-Levy, Biochem. Z., 2 , 319 (1906). (156) J. Hamalainen and L. Sjostrom, Skand. Arch. Physiol., 24, 113 (1911). (157) J. Hamiilainen, Skand. Arch. PhysioE., 27, 141 (1912). (158) Y. Asahina and M. Ishidate, Ber., 68, 947 (1935). (159) M. Ishidate, J . Pharm. SOC.Japan., 49, 56 (1929). (160) J. Hamalainen, Skand. Arch. Physiol., 24, 1 (1910). (161) R. Kuhn and 1rmentr.ut Low, Z. physiol. Chem., 264, 139 (1938). (162) R. T. Williams, Biochem. J., SS, 1519 (1939). (163) E. Fromm and P. Clemens, Z. physiol. Chem., S4,385 (1901). (164) H. Fischer, Z. physiol. Chem., 70, 256 (1910). (165) R. T. Williams, Biochem. J., 84, 600 (1940).
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THE SUBSTITUTED-SUCROSE STRUCTURE OF MELEZITOSE
BY EDWARDJ . HEHRE Department of Bacteriology and Immunology, Cornell University Medical College, New Yo&, New York
CONTENTS I. Introduction. . . . ......... 11. The Concept of S tructual Relationship of Melezitose and Suerose ... . . . .278 1. Development of the Concept through Analogy with Other S ugars 2. Incomplete Status of Earlier Evidence on Individual Ring St ructures and Configurations. ................................ 280 111. A Bacterial Degradation of Melezitose to Sucrose.. . . . . . . . . . . . . . . . . . . . . . 282 1. Recognition of the Selective Action of Proteus Bacteria.. . . . . . . . . . . . . . . 282 2. Production of Invertase-sensitive Material from Melezitose by Proteus ............................................. Vulgaris 0x2.. 3. Identification of the Invertase-sensitive Product as Sucrose.. . . . . . . . IV. Melezitose Degradation by Cell-free Proteus Enzymes. . . . . . . . . . . . . . . . V. Melezitose as a Sucrose-ended Sugar.. . . . . . . . . . . . . . . . . . . . . . . . . 288
I. INTRODUCTION The trisaccharide melezitose, found in the mannas, honeydews, and other sweet exudations of a wide range of plants, has been the subject of many studies since its crystallization by Bonastre’ more than a century ago. A notable review of these studies was given by the late Professor C. S. Hudson in an earlier volume of this series.2 The present paper deals with one of the major questions raised in that review, and may be considered an epilogue to it. Throughout most of the long period of development of knowledge about melezitose, chemists have looked upon that compound sugar as a relative of sucrose, namely, as a D-glucosyl-sucrose. This relationship is represented, for example, in the formula 3-a-~-glucopyranosy~-/3-~fructofuranosyl a-D-glucopyranoside, generally assumed in recent times to express the complete structure of melezitose. The analysis of Professor Hudson’sla however, made it clear that while sufficient evidence wa8 available in 1946 to formulate melezitose as 3-a-~-gZucopyranosyl-~jructofuranosyl a-D-glucopyranoside, no experimental data bearing on the configuration of the D-fructose unit, and thus on the important question (1) Bonastre, J . Pharm., 121, 19, 443, 626 (1833). (2) C. S. Hudson, Advunces in Carbohydrate Chem., 2, 1 (1946). 277
278
EDWARD J. HEHRE
of the relationship of melezitose to sucrose, had ever been obtained. The stimulus to investigate this question found a response in our laboratory because of the circumstance that experiments had just been completed on a novel method for detecting trace amounts of sucrose. Through the use of this method as a guide, a biological system was discovered that causes the degradation of melezitose to sucrose (Hehre and Carlsona). It is the present purpose to discuss these experiments in the light of previous observations related to the presence of the sucrose moiety in melezitose.
11. THE CONCEPTOF STRUCTURAL RELATIONSHIP OF MELEZITOSE AND SUCROSE 1. Development of the Concept through Analogy with Other Sugars
It is of historical interest that Berthelot4 in reports published between 1856 and 1859 classified melezitose (along with trehalose) as one of a group of sugars analogous to sucrose. Melezitose was described as a nonreducing, alkali-stable disaccharide that was poorly fermented by yeast until after acid hydrolysis, when D-glucose was formed. Thirty years later Alekhine6 showed that melezitose is not a sucrose-like disaccharide but instead a trisaccharide whose hydrolysis by acid proceeds in two distinct stages, the first with a rapid rate (like the hydrolysis of sucrose) and the second with a slow rate (like that of maltose). Alekhine found D-glucose and a new disaccharide which he named turanose as products of the first stage of acid hydrolysis of melezitose. Turanose was thought to be a D-glucosyl-n-glucose, related to but not identical with maltose, since only D-glucose was identified following acid hydrolysis. However, Georges Tanrete in 1906 finally proved that turanose is composed of D-glucose and D-fructose; both hexoses were isolated from an acid hydrolysate prepared with care to avoid the otherwise extensive destruction of the D-fructose. Tanret showed moreover that turanose is a D-glucosylD-fructose and not a D-fructosyl-D-glucose, since it resists oxidation by bromine. Melezitose was thus discovered to be built up of the same units as gentianose, namely, of two molecules of D-glucose and one molecule of D-fructose. (3) E. J. Hehre and A. S. Carlson, Arch. Biochem. Biophys., 86, 158 (1952). (4) M. Berthelot, Ann. chim. phys., [3], 46, 66 (1856); [3], 66, 269 (1859); also Compt. r e d . , 47, 224 (1858). Berthelot gave the name melezitose (from le mdlhze, the larch tree) to the new sugar that he, following Bonastre, had crystallized from the
larch manna of Briangon. (5) A. Alekhine, Ann. chim. phys., [6], 18, 532 (1889). (6) G. Tanret, Compt. rend., 143, 1424 (1906); Bull. SOC. chim., [3], 86, 816 (1906).
STRUCTURE O F MELEZITOSE
279
Following Tanret’sa discovery that turanose is a D-glucosyl-D-fructose, the possibility was widely recognized that melezitose might have the structure of a D-glucosyl-sucrose, as shown in formula I. Turanose D-glucose
-
< D-fructose < > D-glucose Sucrose
I This formulation received support from studies showing that a similar type of structure is possessed by other sugars. In the case of raffinose, for example, Neuberg’ was able to obtain D-galactose and crystalline sucrose following the action of the a-D-galactosidase of almond emulsin. Similarly, Bourquelot and Bridela obtained D-glucose and crystalline sucrose from gentianose hydrolyzed by the p-D-glucosidase component of almond emulsin. The existence of these trisaccharide analogues of sucrose made it seem the more credible that melezitose was of the same class. The insusceptibility of melezitose to yeast invertase,6 which readily hydrolyzes raffinose and gentianose as well as sucrose, was, however, not easy to reconcile with that view. I n 1926, Kuhn and von Grundherrg seriously argued for the concept of melezitose as a derivative of sucrose after excluding a cyclic arrangement for the three hexose units on the basis that Alekhine6 had obtained a crystalline hendecaacetate from melezitose. (Through elimination of a n extra molecule of water, a cyclic structure would present only nine hydroxyl groups.) These investigatorsg reported no enzymic or chemical cleavage of melezitose yielding sucrose or other non-reducing disaccharide, but they offered evidence suggestive for their hypothesis by analogies drawn between various hydrolyses of melezitose and sucrose. Melezitose was found, for example, to be split to D-glucose by the so-called “glucosaccharase l 1 enzyme preparations from Aspergillus oryzae and Lowenbrau yeast which hydrolyzed sucrose. The long-recognized inability of ordinary yeast invertase to attack melezitose6*10was explained by the assumption that this enzyme is a type of “fructosaccharase” that requires an unsubstituted (terminal) D-fructose molecule. Actually, the experiments of Kuhn and von Grundherr with the aspergillus and Lowenbrau yeast enzymes cannot be taken as evidence that melezitose contains the (7) C. Neuberg, Biochem. Z., 3, 519 (1907). (8) E. Bourquelot and M. Bridel, Compt. rend., 171, 11 (1920). (9) R. Kuhn and G. E. von Grundherr, Ber., 69, 1655 (1926). (10) C. S. Hudson and S. F. Sherwood, J . Ant. Chem. Soc., 42, 116 (1920).
280
EDWARD J. HEHRE
sucrose moiety because, as Bridel and Aagaard" and Weidenhagen12 showed subsequently, these enzymes act on various a-D-glucosidic bonds and not exclusively and specifically on that of sucrose; that is, according to the latter authors these enzymes should be classed as a-wglucosidases rather than as D-glucosaccharases. Likewise, the explanation assumed by Kuhn and von Grundherr for the inactivity of yeast invertase on melezitose does not indicate that the sucrose structure is necessarily present, although it does remove an important objection to the idea. One of the major points advanced by Kuhn and von Grundherrg for the substituted-sucrose structure of melezitose was the extreme ease of acid hydrolysis of one of the linkages, which had earlier led Alekhine6 to the discovery of turanose and the trisaccharide nature of melezitose. For years this feature was accepted as virtual proof of the presence of sucrose in the melezitose molecule. However, the opinion that the ease of hydrolysis was evidence for the furanoid form of the D-fructose ring lost all validity with the discovery by Purves and Hudson1*that methyl D-fructopyranoside is hydrolyzed by acids with the same ease as methyl D-fructofuranoside; moreover, the ease of hydrolysis never was evidence concerning the a- or j3-configuration of the D-fructose unit in melezitose.a Nevertheless, over the years, the concept of melezitose as a D-glucosylsucrose was widely held, especially since no D-glucose < > D-fructose moiety had ever been found in Nature that was not a-D-glucopyranose < > j3-D-fructofuranose (i.e., sucrose). Indeed, this more or less intuitive formulation came to be regarded as a proven structure by many chemists, and was assigned without reservation in many works of reference before the clarifying account given by Hudson.2
2. Incomplete Status of Earlier Evidence on Individual Ring Structures and Configurations Experimental support for the hypothesis that melezitose may be a substituted sucrose came from determinations of the ring structures and configurations of the individual sugar components involved. Actually, final proof was not achieved for the lack of a single point of information. Conclusive evidence for the pyranoid-ring structures of the D-glucose units in melezitose was obtained through the methylation experiments of Zemplh and BraunI4 and especially through those of Leitch16 who isolated two molecular equivalents of crystalline tetramethyl-D-gluco(11) M. Bridel and T. Aagaard, Bull. soc. chim. bid., 9, 884 (1927);T.Aagaard, Tidsskr. Kjemi og Bergvesen, 8, 5, 16, 35 (1928);Chem. Abstractrr, 24, 1089 (1930). (12) R. Weidenhagen, Z. Ver. deut. Zucker-Ind., 78, 406, 781 (1928); 79, 115 (1929);80,383 (1930). (13) C.B. Purves and C. S. Hudson, J . Am. Chem. Soc., 60, 1170 (1937). (14) G. Zemplh and G. Braun, Ber., 69, 2230 (1926). (15) Grace C.Leitch, J . Chem. Soc., 588 (1927).
STRUCTURE O F MELEZITOSE
281
pyranose from the hydrolyzate of hendecamethylmelezitose. The methylation experiments of the latter author also showed that the D-fructose fragment of melezitose in all probability has the same (furanoid) ring structure as the D-fructose component of sucrose. That is, when the trimethyl-D-fructose portion of the hydrolyzate was further methylated and the resulting methyl tetramethyl-D-fructoside hydrolyzed, a reducing sugar (presumably 1,3,4,6-tetramethyl-~-fructofuranose) was obtained that agreed in physical properties with the tetramethyl-Dfructose obtained from the hydrolysis of octa- or heptamethyl-sucrose.'6 By the use of the periodate oxidation technique, Richtmyer and Hudson16 confirmed the pyranoid form of the two D-glucose units in melezitose, and in addition conclusively proved the presence of a furanoid D-fructose unit. Their data show that four moles of periodic acid are consumed, with two moles of formic acid (but no formaldehyde) liberated per mole of melezitose. Some formaldehyde would have been produced if either of the D-glucose rings were of furanoid form, while more than four moles of periodate would have been reduced if either of the D-glucose rings were larger than the six-membered form. Furthermore, since the pyranoid structures thus indicated for both D-glucose units account exactly for the four moles of reagent used and for the two moles of formic acid released, it is evident that the D-fructose unit was not attacked by the periodic acid and therefore must be of the furanoid ring type with no pair of hydroxyl groups on adjacent carbon atoms. Support for this conclusion pertaining to the fructose ring form was obtained by Richtmyer and Hudson16 in additional experiments in which the presence of intact D-fructose in the oxidized melezitose molecule was demonstrated. All of the foregoing evidence is consistent with a D-glucosyl-sucrose structure for melezitose (I). Indeed, when supplemented by experimental data on the structure of turanose, which is now known with assurance to be 3-c~-~-glucopyranosyl-~-jructose, l7 the evidence permits D-glucomelezitose to be written as 3-a-~-glucopyranosyl-~-fructofuranosyl pyranoside. This expression lacks assignment only of the a- or p-form for the D-fructose unit and for the right-hand D-glucose unit, which features however are essential for a decision on the identity or nonidentity of melezitose with a D-glucosyl-sucrose. Reasonably good evidence that the D-glucose unit in question possesses the a-configuration was obtained from enzymic studies which showed that the 8-D-glucosidase of almond emulsin has no appreciable effect upon r n e l e ~ i t o s ewhile ~~~~ preparations containing a-D-ghcosidase from yeast, malt, Aspergillus oryzae, and other organisms hydrolyze melezitose into (16) N. K.Richtmyer and C. S. Hudson, J . Org. Chem., 11, 610 (1946). (17)The reader is referred to the review article2 of Hudson for a thorough treatment of the development of knowledge of the turanose structure.
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EDWARD J. HEHRE
its three hexose components.1lP12 However, as mentioned a t the beginning, no experimental data were obtained bearing on the question of the a- or P-configuration of the D-fructose unit. The well established observation that yeast invertase is without action on melezitose is of no help in choosing the proper allocation, Insusceptibility to invertase cannot be taken as evidence that melezitose contains an a- rather than a P-type D-fructose linkage because the presence of a glucosyl substituent on the D-fructose unit might suffice to prevent the enzyme from acting.Qn12018On the other hand, neither of course does the failure of invertase, or P-D-fructofuranosidase, indicate the presence of a P-D-fructose linkage and consequently sucrose in the molecule. Isolation of the non-reducing disaccharide portion of melezitose would permit the last point of structure to be settled, but this direct type of solution has long been regarded as not likely to be accomplished. Treatment of melezitose with acid causes the preferential rupture of the unknown glycosidic bond, which precludes isolation of the D-glucose < > D-fructose fragment. Moreover, treatments with a-D-glucosidase preparations cause the release of all three hexose components rather than yield any non-reducing disaccharide, presumably, according to Weidenhagen,l2.l9because of the presence and equal susceptibility of the two a-D-glucosidic bonds in melezitose. Weidenhagenlo (p. 187) in fact expressed the futility of seeking the non-reducing moiety through selective enzymic splitting in strong and unequivocal terms, viz., “Die Annahme, dass auf enzymatischem Wege eine Spaltung der Melezitose in Glucose und Rohrzucker oder Glucose und Turanose moglich sei, ist ad absurdurn gefuhrt.” Thus, the final point required to complete the knowledge of the structure of melezitose and show its relationship to sucrose (i.e., a decision on the configuration of the D-fructose unit) not only remained undetermined, but its solution also seemed remote because of the peculiar circumstances noted above. Solution was achieved, however, with the finding by Hehre and Carlson3 of a biological degradation yielding the non-reducing disaccharide entity which, with the kind help of Professor C. S. Hudson, was conclusively proved to be sucrose.
111. A BACTERIAL DEGRADATION OF MELEZITOSE TO SUCROSE 1. Recognition of the Selective Action of Proteus Bacteria
On the premise that previous observations with a few a-D-glucosidase preparations were too limited to establish the biological equivalence (18) Mildred Adams, N. K. Richtmyer, and C . S. Hudson, J . Am. Chem. Soc., 66, 1369 (1943). (19) R.Weidenhagen, Ergeb. Enzymforsch., 1, 168 (1932).
STRUCTURE O F MELEZITOSE
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claimed by Weidenhagen l9 for the two a-D-glucosidic linkages in melezitose, a survey was undertaken in which diverse bacteria were examined for the capacity to split the acid-stable linkage of the trisaccharide a t a faster rate than the acid-labile linkage. The survey was made with the aid of an enzymic-serological test for sucrose, capable of detecting that sugar in exceedingly minute quantities in the presence of large quantities of other sugars, including meleaitose. This test, which seemed ideally suited for recognition of the slightest degradation of melezitose to sucrose, is based on the specific conversion of sucrose to the polysaccharide dextran by the enzyme dextransucrase of Leuconostoc mesenteroides20s21with recognition of the dextran so formed, by serological means.20,22 Suspensions of various barteria wcre incubated with melezitose in the presence of dextransucrase, and the supernatant fluids of such mixtures examined for their capacity to give serological precipitation with dextran-reactive antiserums. Negative results were obtained with bacteria of many genera and species. However, fluids from incubated mixtures of melezitose with variants of Proteus bacteria commonly used in the laboratory diagnosis of rickettsia1 diseases (i.e., Proteus 0x2, X2, 0x19, X19, OXK, XK) gave precipitin reactions for dextran when diluted several hundredfold. This was taken as presumptive evidence that sucrose had been released from the melezitose by the Proteus bacteria; the amount produced in the initial experiment, however, could not have exceeded one per cent of that theoretically obtainable from a D-glucosyl-sucrose, since fluids with degrees of serological reactivity similar to those of the mixtures of Proteus cells plus 10% melezitose could be produced by incubating solutions of 0.02 to 0.1% sucrose with the same dextransucrase preparation under the same conditions.
2. Production of Invertase-sensitive Material from Melezitose by Proteus Vulgaris O X 2 By altering the culture medium used for growing the Proteus bacteria, and by using cell suspensions of greater density, the production from melezitose of abundant amounts of material susceptible to invertase action, as well as of reducing sugars, was readily shown.3 Figure 1 illustrates the degradation of a 5 % solution of melezitose monohydrateZ3 (20) E. J. Hehre, Science, 93, 237 (1941); E. J. Hehre and J. Y. Sugg, J . Exptl. Med., 76, 339 (1942). (21) E. J. Hehre, J. Bid. Chem., 163, 221 (1946). (22) J. Y. Sugg and E. J. Hehre, J. Zmntunol., 43, 119 (1942). (23) The melezitose (Pfanstiehl) used in our experiments was isolated from “honeydew honey,” one of the important sources discovered by Hudson and Sherwood.lo
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EDWARD J. HEHRE
by young, washed cells of Proteus vulgaris, OX2 variety. Three distinct phases are seen: an initial or lag period of two or three days during which little change is found; a phase of rapid production both of invertasesensitive material and of free reducing sugars; and a final phase in which the free reducing sugar content further increases while the “sucrose ”
DAYS
FIQ. 1.LAction of Proteus OX2 bacteria on melezitose monohydrate (initial concentration, 5.0%) in system held at pH 5.6 and 23°C. Open circles represent free reducing sugars, calculated as glucose; solid circles represent invertase-sensitive material, calculated as sucrose.
content declines. The formation and subsequent partial disappearance of invertase-sensitive material, together with the production of reducing sugars in progressively increasing quantity suggests that the Proteus bacteria, possibly after a period of autolysis, had released an enzyme or enzymes catalyzing the reactions: Melezitose Sucrose
+ HzO+ Sucrose + D-Glucose + HzO-+ D-Fructose D-Glucose
Moreover, the disproportionately large amount of reducing sugar liberated in the relatively early period suggests that other degradative reactions also had occurred. The maximal concentration of the invertase-sensitive product, found
STRUCTURE O F MELEZITOSE
285
on the sixth and seventh days of the experiment, was 43% of that theoretically expected from a 5 % solution of a D-glucosyl-sucrose (monohydrate). In other experiments, maximal “sucrose” yields from 38 to 56% were found a t corresponding periods. In view of these favorable results, isolation of the invertase-sensitive material was undertaken. Part of the Proteus-melezitose mixture of Fig. 1, for example, was taken on the seventh day of incubation and, after removal of bacteria and heatcoagulable protein, was placed on a carbon-Celite columnz4for fractionation. After adsorbed reducing sugars (D-glucose and D-fructose) had been eluted with water, a fraction was obtained by elution with 0.5% aqueous phenol that contained about half of the invertase-sensitive material present in the original digest, with little accompanying free reducing sugar or undegraded melezitose. On vacuum evaporation of this fraction and treatment of the resulting sirup with ethanol, a crystalline product was readily obtained.3
3. IdentiJication of the Invertase-sensitive Product as Sucrose The crystalline sugar was non-reducing toward alkaline copper and ferricyanide reagents and, on paper chromatograms, migrated as a single component with the velocity of natural sucrose. Its specific optical +65.8”, in rotation, measured in Dr. Hudson’s laboratory,2bwas good agreement with the rotation of pure sucrose. Moreover, when hydrolyzed with acid or with yeast invertase and analyzed for reducing sugars, the melezitose-derived product yielded an amount of invert sugar corresponding t o sucrose. Chromatograms26 of the acid-hydrolyzed material confirmed the presence of two components that migrated with velocities corresponding to D-glucose and D-fructose. The rate of hydrolysis of the melezitose-derived material by acid was, furthermore, identical with that of natural sucrose (Fig. 2). Additional evidence that the product obtained from melezitose is sucrose was provided by X-ray diffraction patterns made in Dr. Hudson’s laboratory26(Fig. 3). I n common with natural sucrose, the melezitose-derived sugar was found to give an olive-green color reaction with the diazouracil reagent of RaybinZ7whereas melezitose and turanose give negative reactions. By acetylation, Drs. Hudson and Fletcher2b prepared a crystalline (24) Edna M. Montgomery, F. B. Weakley and G. E. Hilbert, J. Am. Chem. SOC., 71, 1686 (1949). (25) The data on the specific optical rotation, X-ray diffraction, and on the octaacetate of the meleeitose product were obtained by Professor C. S. Hudson, Dr.
Hewitt G. Fletcher, Jr., and Dr. Nelson K. Richtmyer of the Laboratory of Chemistry and Chemotherapy, National Institutes of Health. (26) S. M. Partridge, Biochem. J., 42, 238 (1948). (27) H. W. Raybin, J. Am. Chem. SOC.,66, 2603 (1933); 69, 1402 (1937).
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EDWARD J. H E H R E
FIG. 2.cChanges in optical rotation, (Y X 50, observed during hydrolysis of 1.0% “sucrose” from melezitose (solid circles) and of 1.0% Bureau of Standards sucrose (open circles) by 1.0 N HCl a t 22°C.; 1, 2 dm.
FIG.3.8,*6-X-Ray diffraction patterns of melezitose, “sucrose ” from melezitose, natural sucrose, and turanose. The diagrams were made by Mr. William C. White of the National Institutes of Health.
STRUCTURE O F MELEZITOSE
287
derivative with [,IDz0 +60.5” (c 1.4, chloroform) and a melting point of 87-89’ which was not depressed on admixture of the test material with authentic sucrose octaacetate. Rotation of the latter substancez8 is +59.6’; the melting point of the stable allotropeJZg89’. The [,ID melezitose-derived sugar, finally, was found3 to serve as a substrate for three different polysaccharide-synthesizing enzymes (dextransucrase from Leuconostoc mesenteroides,20~21 amylosucrase from Neisseria perJ ~ U V U and , ~ ~ levansucrase from Streptococcus s ~ l i v u r i u s ~ that ~ ) are operative upon sucrose but not upon melezitose, turanose, or the common natural di- or mono-saccharides.
IV. MELEZITOSE DEGRADATION BY CELL-FREE Proteus ENZYMES On the basis of the above evidence, there can be no doubt that the product obtained from melezitose by the action of Proteus bacteria is sucrose. The rather complicated course of the action of the Proteus bacteria on melezitose (Fig. l), nevertheless, might make somewhat uncertain the assumption that the sucrose had been formed by direct hydrolytic degradation rather than through a more complex series of reactions perhaps dependent upon the living bacteria. All uncertainty was dispelled, however, when it was found3 that suspensions of Proteus bacteria in acetate buffer kept a t room temperature for several days attack melezitose without delay, and that active, soluble enzyme preparations could be obtained from such “aged” suspensions. Figure 4 illustrates the action of a cell-free, Proteus enzyme preparation on melezitose. It is evident that a lag period was not present and that essentially equimolecular amounts of free reducing sugar (as glucose) and of invertase-sensitive material (as sucrose) were released during the first four or five days of incubation. On the fifth day, when approximately twothirds of the melezitose had been degraded, paper chromatograma showed the presence of three components, which corresponded to melezitose, sucrose and D-glucose; other sugars, including turanose and D-fructose, were not detected. The maximal quantity of sucrose released corresponded to about 75% of that theoretically expected from a D-glucosyl-sucrose. The disproportionately large amount of reducing sugars present in the mixture after the fifth day of incubation can be accounted for on the basis of degradation of some of the newly formed sucrose. I n separate tests, the (28) C. S. Hudson and J. M. Johnson, J . Am. Chem. SOC.,37, 2748 (1915). (29) R. P.Linstead, A. Rutenberg, W. G . Dauben and W. L. Evans, J . Am. Chem. SOC.,62, 3260 (1940).
(30) E.J. Hehre and Doris M. Hamilton, J . Biol. Chem., 166, 777 (1946);J . Bact., 66, 197 (1948);E.J. Hehre, Advances i n Enzymol., 11, 297 (1951). (31) E. J. Hehre, Proc. SOC.Exptl. Biol. Med., 68, 219 (1945).
288
EDWARD J. HEHRE
same enzyme preparation was found capable of attacking sucrose; whether one and the same enzyme is involved in the action on sucrose and on the turanose linkage of melezitose is not known. However, the important point established by the experiment of Fig. 4 is that the pro30
t
10
D AVS
FIG.4.8-Action of cell-free, Proteus enzyme solution upon melezitose, initial concentration 20 m M . Solid circles represent sucrose; open circles represent reducing sugars, calculated as glucose.
duction of sucrose from melezitose by Proteus action is the result of direct enzymic hydrolysis.
V. MELEZITOSE AS
SUCROSE-ENDED SUGAR Conclusive proof is thus at hand that, as long surmised, the structure of melezitose includes the sucrose moiety; and, since the constitution of sucroses2is known to be fi-D-fructofuranosyl a-D-glucopyranoside, that the full structure of melezitose is 3-ff-D-glucOpyranOSyl-fi-D-frUCtOfUrUnOSyl a-D-glucopyranoside (11). The identification of sucrose as the nonreducing disaccharide portion of melezitose actually establishes only one new point, namely, that the D-fructose unit of the trisaccharide has the fi- and not the a-configuration; but this was the final point required to complete the knowledge of the structure of melezitose. Moreover, the degradation to sucrose is significant beyond resolving the question of the (32) I. Levi and C. B. Purves, Advances in Carbohydrate Chem., 4, 1 (1949). A
STRUCTURE OF MELEZITOSE
289
configuration of the D-fructose unit because it confirms completely and in an easily understandable way all the other details of structure of the D-fructose < > D-glucose entity of melesitose that had been established earlier. The presence of sucrose, for example, proves the pyranoid ring form of the D-glucose unit of the non-reducing entity, in confirmation of the methylation experiments of Zempl6n and Braun14 and Leitchlb and of the periodate oxidation experiments of Richtmyer and Hudson;lB it likewise confirms the a-configuration of the same D-glucose unit, in HOCHI
H
OH
H
OH
H
I1
keeping with the earlier enzymic studies of Weidenhagen.12 The isolation of sucrose also furnishes an independent proof of the furanoid ring form of the D-fructose unit in melesitose, which originally was indicated by the methylation studies of Leitch16 and established through the periodate studies of Richtmyer and Hudson. l6 The complete concurrence with these diverse earlier findings adds strong support to the conclusion that melesitose can now definitely be classed as one of the “sucrose-ended ” sugars of Nature. Melezitose, however, differs in certain respects from most of the currently known members of this rapidly growing (and evidently large) class of saccharide. For example, sucrose, raffinose, gentianose, s t a c h y o ~ e and , ~ ~ v~e~r ~b a s c ~ s e ,as ~ ~well ~ as the recently described “glucofructosane B ” or “inulobiosyl glucose” (l-g-~fructofuranosyl-P-D-fructofuranosyl a-~-glucopyranoside~~~), “kestose” (64D-fructofuranosyl-P-D-fructofuranosyla-D-ghcopyranosideJh),and “erlose ” (33) C. Tanret, Bull. soc. chim., 131, 27, 947 (1902); M. Onuki, Sci. Papers Inst. Phys. Chem. Research (Tokyo), 20, 201 (1933); R. A. Laidlaw and Claire B. Wylam, J . Chem. SOC.,567 (1953). (34a) S. Murakami, Proc. Imp. Acad. (Tokyo), 16, 12 (1940). (34b) R. Dedonder, Bull. SOC.chim. biol., 34, 144, 157, 171 (1952); J. H. Pazur, J . Biol. Chem., 199, 217 (1952). (340) N. Albon, D. J. Bell, P. H. Blanchard, D. Gross, and J. J. Rundell, J. Chem. Boc., 24 (1953).
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EDWARD J. HEHRE
(4-a-~-glucopyranosyl-a-~-glucopyranosyl P-D-fructofuranosideaM),all possess a terminal (unsubstituted) /%linked D-fructofuranose unit; all are susceptible to the action of yeast invertase; and all (except possibly verbascose, for which no report of a test was found) give a positive color reaction with d i a z o u ra ~ i l . ~Only ~ planteose, recently to be 6-cu-D-ga~actopyranosy~~-~-fructofuranosy~ a-D-glucopyranoside, resembles melezitose in lacking a terminal 8-linked D-fructofuranose unit, in being insusceptible to yeast invertase, and in giving a negative reaction with diazouracil. The effects of substitution in the &fructose moiety of sucrose, at least by an a-linked D-glucopyranosyl unit at the third carbon atom (melezitose) or by an a-linked D-galactopyranosyl unit at the sixth carbon atom (planteose), show that neither yeast invertase nor diazouracil is a completely reliable reagent for the recognition of the chemicallycombined sucrose moiety (see Levi and Purvesa2). The presence of a substituent on the &fructose unit of melezitose is associated with still another effect. That is, the a-D-glucopyranosyl residue at the sucrose end of the melezitose molecule, unlike that of sucrose, does not undergo polymerization to dextran or glycogen under the influence respectively of Leuconostoc mesenteroidessJ6or Neisseria per$avaaO systems. By contrast, it has long been known that the /3-D-fructofuranose residue of raffinose, like that of sucrose, does undergo biological polymerization to levan.a1*s6 Molecular models as well as the perspective formula of melezitose (11) suggest the possibility that a sort of structural “ overlapping ” may underlie the failure of certain reactions expected of the sucrose union. The preferential splitting of the turanose(over the sucrose-) linkage, by Proleus enzymes, may also perhaps be based on such a hindrance, though ample evidence has now been obtained87 t o show that the substrate specificity of a-D-ghcosidases is not invariably as broad as originally postulated by Weidenhagen. l8 (34d) J. W. White, Jr., and Jeanne Maher, J. Am. Chem. Soc., 76, 1259 (1953). A ample of this sugar, furnished by Dr. White, was found to give a strongly positive
Raybin” test. (34e) N. Wattiez and M. Hans, BUZZ. acad. roy. med. Belg., 8, 386 (1943); D. French, G. M. Wild, B. Young, and W. J. James, J. Am. Chem. Soc., 76, 709 (1953). (35) H. L. A. Tarr and H. Hibbert, Can. J . Research, B, 6, 414 (1931). (36) M. W. Beijerinck, Folia Microbiol., 1, 377 (1912); F. C. Harrison, H. L. A. Tarr and H. Hibbert, Can. J . Research, B, S, 449 (1930); E. J. Hehre, Dorothy S. Genghof, and J. M. Neill, J . Immunol., 61, 5 (1945). (37) B. Helferich, in J. M. Sumner and K. Myrbitck, “The Enzymes,” Academic Press, New York, 1950, Vol. 1, pp. 95-96; C. Neuberg and Ines Mandl, ibid., pp. 542-544; A. Gottschalk, ibid,, pp. 577-580.
COMPOSITION OF CANE JUICE AND CANE FINAL MOLASSES
BY W. W. BINKLEYAND M. L. WOLFROM Department of Chemistry, The Ohio Slate University, Columbus, Ohio
CONTENTS I. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291 11. Composition of Cane Juice.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292 1. Carbohydrates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292 a. Normal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292 b. Bacterial.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295 2. Enzymes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296 3. Vitamins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296 4. Nitrogen Compounds.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297 5. Non-nitrogenous Acids. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298 6. Pigments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 7. Waxes, Sterols and Lipids.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 8. Inorganic Components.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301 .......................................... 301 9. Summary. . . . . . 111. Composition of Ca . . . . . . . . . . . . . 303 1. Carbohydrates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304 . . . . . . . . 308 2. Vitamins.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308 3. Nitrogen Compounds. . . . . . . . . . . . 4. Non-nitrogenous Acids. . . . . . . . . . . . . . . . . . . . . . . . . . . . 309 5. Pigmented Materials. . . . . . . . . . . . . . . . . . . . . . . . . 311 . . , 311 6. Waxes, Sterols and Lipids. . . . . . . . . . . . . . . . 7. Odorants.. . . . . . . . . . . . . . . . . . . . . . . . . . . 312 8. Inorganic Components.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312 9. Summary . . . . . . . . . . . . ........................................ 312 Addendiim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314
I. INTRODUCTION The expressible juice from sugar cane is the precursor of blackstrap or final molasses. Components of the juice constitute the major part of this by-product. However, a significant portion of the final molasses consists of the altered reaction products formed under factory conditions from the juice constituents. A summary of t,he composition of cane juice is presented as a necessary background for any discussion of cane final molasses. Cane juice is an aqueous solution circulating in the living plant and carrying materials required for growth and metabolism. It is therefore extremely complex. It distinguishes itself from other plant juices or saps by its characteristically high content of sucrose. The 291
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W. W. BINKLEY AND M. L. WOLFROM
cane juices referred t o in this writing are “screenedyycrusher juicea; they closely approximate the normal plant juice. The range in variability of these juices is demonstrated by their empirical analyses’ (basis whole juice) : water, 78-86 % ; sucrose, 10-20 %; reducing sugars, 0.5-2.5 % ; other organic compounds, 0.5-1 .O%; ash, 0 . 3 4 7 % ; p H 5.2-6.2. In the early part of the 1951 season a typical Florida crusher juice showed a pH of 5.8 and contained (basis whole juice) : 18.55’ Brix solids at 2OOC. ; sucrose, 16.22%; reducing sugars, 0.5%.2 The pressure on the crusher rolIs which express this juice from the shredded cane may be as much as 75 tons per foot of roll width.’ Leaving the crushers the cane (bagasse) is extracted during passage through a series of 3-roll mills; considerable water is added and these liquids are then much less representative of the actual juice in the cane.
11. COMPOSITION OF CANEJUICE 1. Carbohydrates a. Normal.-The production of sucrose from sugar cane is revealed in the earliest records of modern ~ i v i l i z a t i o n . ~The ~ ~ application of the scientific method to this process began slightly more than a century ago.6 Three species of the genus Saccharum are grown for the industrial production of sugar; they are spontaneum, robustum and o$cinarum.a The sugar cane is a reed or grass and is propagated by joint cuttings (“plant cane”). Several cuttings (“stubble cane”) are made from each planting.6 Seedlings are required for new varieties and hybrids. As the seeds are very difficult to germinate, this work has been carried out in the experiment stations and has led to such variety designations as POJ 234 (variety 234 of Proefstation Oost Java), BH (Barbados Hybrid) or D (Demarara, British Guiana).8 The cane seldom matures before harvest in Louisiana, the danger of frost there confining the growing period to about nine months. This period is about fifteen months in Cuba and is eighteen to twenty-four months in Hawaii. (1) E. R. Riegel, “Industrid Chemistry,” 5th ed., Reiiold Publishing Corp., New York, 1949. (2) Private communication from Dr. B. A. Bourne of the United States Sugar Corp., Clewiston, Florida. (3) Noel Deerr, “History of Sugar,” Chapman and Hall, London, 1949, Vol. I, p. 12. (4) E. 0. von Lippmann, “Geschichte dea Zuckers,” 2nd ed., J. Springer, Berlin, 1929. (5) J. B. Avenquin, J . chim. ma,pharmacie tosicologie, [2] 1, 132 (1836). (6) A. Van Hook, “Sugar,” The Ronald Press Co., New York, 1949, p. 23.
COMPOSITION
OF CANE JUICE AND CANE FINAL MOLASSES
293
Reducing sugars, 4-8%,’ are known to be present in cane juice; they are n-glucose and D-fructose. The acetylation of lyophiliaed (freeaedried) normal cane juice solids followed by chromatography on a magnesium acid silicate of these acetates led to the iso1at)ion and proper identification of the sugars as crystalline derivatives.8 Methods of approximate analysis in solution for sucrose, D-glucose and D-fructose have been extensively developed and refined.g They depend upon the fact that sucrose is a non-reducing disaccharide of rather high optical rotation, [a],, +66”, and that on acid hydrolysis to its reducing sugar components, the mixture is levorotatory because of the high equilibrium levorotation, [aID -92”, displayed by D-fructose over that of D-glucose, [.ID +52.5”. The fact that n-fructose is highly tautomeric and changes its equilibrium rotation markedly with temperature is also employed in analysis. The other carbohydrates in cane juice are the soluble polysaccharides vaguely classified under the terms “hemi-celluloses, soluble gums and pectins.” It is possible that some of these polysaccharides may enter the juice during the milling of the cane as the plant cell structure is destroyed. A gummy product has been isolated from cane fiber by alkali extraction followed by alcohol precipitation, Acid hydrolysis of this substance yielded crystalline D-xylose and L-arabinose.l o Such gums in Trinidad cane juices were isolated by alcohol precipitation at suitable hydrogen ion concentration and assayed for pentose content by the Tollens 2-furaldehyde assay; the results showed an “apparent pentosan” content of 0.04-0.07%” of the Brix solids. Pectins are present in plant juices. These are now considered to be polymers containing a basic chain, designated pectic acid, of 4-linked Pgalactopyranuronic acids, the. carboxyl groups of which exist in part as methyl esters and in part as salts. Variable amounts of an araban and a galactan are associated with this polysaccharide.12 A method of approximate assay for pectic substances13 depends upon saponification (7) Unless otherwise noted, constituent concentrations of cane juice and of cane final molasses are expressed on the basis of the solids contents of the source materials. When the solids contents are unavailable, the normal values of 17% and 80% for cane juice solids and cane final molasses solids, respectively, have been employed to closely estimate these constituent concentrations. (8) W. W. Binkley and M. L. Wolfrom, J . Am. Chem. Soc., 68, 1720 (1946). (9) C. A. Browne and F. W. Zerban, “Physical and Chemical Methods of Sugar Analysis,” John Wiley and Sons, Inc., New York, 3rd ed., 1941. (10) C. A. Browne, Jr., and R. E. Blouin, Louisiana Expt. Sta. Bull. 91 (1907). (11) R. G. W. Farnell, Intern. Sugar J., 26, 480 (1924). (12) E. L. Hirst and J. K. N. Jones, Advunces in Carbohydrate Chem., 2,235 (1946). (13) M. H. Carre and D. Haynes, Biochem. J . , 16, 60 (1922).
294
W. W. BINKLEY AND M. L. WOLFROM
followed by the precipitation and weighing of the water-insoluble (but impure) calcium pectate. Application of this procedure to Trinidad cane juicesll showed the presence of 0 . 0 4 1 % of pectins (as calcium pectate) in the Brix solids. Uronic acids are readily decarboxylated on heating with hot mineral acids. An assay for their presence depends upon the determination of the evolved carbon dioxide14and when applied to Louisiana cane juice indicated a uronic acid content of 0.44% of the ash-free solids.16 The uronic acids are derived from the cane fiber and pectins. The methoxyl content of the juice was found by a modified hydriodic acid digestion method16 to be 0.08% of the ash-free solids.Is It is presumably derived from the pectins present. Starch is readily detected by iodine coloration and has been reported in the Uba cane juice of South Africa.” The starch content of Louisiana cane juice has been determined quantitatively's by extraction of the nondialyzable juice fraction with perchloric acid, precipitation of the starch with iodine, decomposition of the starch-iodine complex with alcoholic sodium hydroxide, hydrolysis of the starch with aqueous hydrochloric acid and estimation of the starch content from the copper reduction value of the hydr01yzate.l~ The average starch content of this juice was found to be 0.012-0.018%;the maximum value was 0.035%.18 The starch is present in the cane just above the nodes, where it apparently serves as a reserve carbohydrate for growth. It is probably not a normal constituent of the plant juice but enters the crusher juice through the mechanical disintegration of the nodes. Cane juice is a rich source of the cyclic alcohol, myo-inositol (the definitive prefix my0 has been suggested to replace meso for the common inositol, m. p. 225OZ0). It was isolated from cane juice by chromatographyzl; bioassay (Beadle methodzz) of the juice showed 0.041% myoinositol.zl A logical companion of this constituent is phytin (a calcium(14) K. U. Lefhvre and B. Tollens, Ber., 40,4513 (1907); A. D. Dickson, H. Otterson and K. P. Link, J . Am. Chem. SOC.,62, 1775 (1930). (15) C. A. Browne and M. Phillips, Intern. Sugar J., 41, 430 (1939). (16) M. Phillips, J . ASSOC. 03.Agr. Chemists, 16, 118 (1932). (17) L. Fevilherade, Proc. S. African Sugar Tech. Assoc., 71 (1929); Chem. Abstracts, 24, 3127 (1930). (18) R. T. Balch, B. A. Smith and L. F. Martin, Sugar J., 16, No. 6, 39 (1952); R. T. Balch, ibid., No. 8, 11 (1953). (19) G. S. Pucher, C. S. Leavenworth and H. B. Vickery, Anal. Chem., 20, 850 (1948). (20) H. G. Fletcher, Jr., L. Anderson and H. A. Lardy, J . Org. Chem., 16, 1238 (1951). (21) W. W. Binkley, M. Grace Blair and M. L. Wolfrorn, J . Am. Chem. Soe., 67, 1789 (1945). (22) G. W. Beadle, J . Biol. Chem., 166, 683 (1944).
COMPOSITION
OF CANE JUICE
AND CANE FINAL MOLASSES
295
magnesium salt of myo-inositol hexaphosphate) ; it was not found in cane juice.21 This juice contained iron which forms a very insoluble salt with myo-inositol hexaphosphate and the modifiedz3phytin assay,z4depending upon the precipitation of ferric phytate, was thus not applicable. Phytin must certainly be a juice constituent since it is found in blackstrap molasses.21 The amount of organic phosphate in cane juice (average ca. 18.7 mg. of phosphoric anhydride per 100 g. of Brix solids) has been estimated from the difference between the total and inorganic phosphorus contents; the presence of hexose phosphates is suggested.26*26a b. Bacterial.-Slime-producing bacteria are associated with the cane plant and these attack cane damaged by frost or by other agents. Some of these bacteria belong t o the Leuconostoc mesenteroides and Leuconostoc dextranicum classifications and form many strains that are difficultly distinguishable. They contain a transglycosidase enzyme system which acts upon sucrose to transfer the D-glucose glycosidic linkage from D-fructose to the D-glucose of another sucrose molecule with the concomitant liberation of D-fructose. This process continues and a polysaccharide molecule is built up containing a-D-glucopyranose units linked 1 -+ 6 and 1 --+ 4 with the former predominating. I n some products other linkages may be present.25 These substances are termed dext r a n ~ ~ ’and - ~ ~have been the subject of considerable investigation since the recently indicated use of acid-modified dextrans as blood extenders. Other bacteria associated with cane and cane products, such as Bacillus mesentericus, contain a transglycosidase enzyme system that transfers the D-fructose glycosidic linkage in sucrose to the D-fructose unit of another sucrose molecule with the liberation of D-glucose. The polysaccharides formed are termed lev an^^*-^^ and consist of D-fructofuranose units joined 2 -+ 6. The dextran-producing bacteria are thermolabile and are destroyed in the mill processing whereas the levan-producing bacteria persist. D-Mannitol is not a normal constituent of cane juicez1but is always (23) E. B. Earley, Ind. Eng. Chem., Anal. Ed., 16, 389 (1944). (24) W. Heubner and H. Stadler, Biochem. Z., 64, 422 (1941). (25) P. Honig, “Phosphates in Clarified Cane Juice,” West Indies Sugar Corp. Rept. 1 (1952); Abstracts Papers Am. Chem. Sac., 121, 15P (1952). (25a) L. F. Wiggins, Intern. Sugar J., 64, 324 (1952). (26) R. L. Lohmar, J . Am. Chem. SOC.,74, 4974 (1952). (27) E. Durin, Compt. rend., 83, 128 (1876). (28) T. H. Evans and H. Hibbert, Advances in Carbohydrate Chem., 2, 203 (1946); Sugar Research Foundation, Sci. Rept. Series, 6 (1947). (29) E. J. Hehre, Transactions N . Y . Acad. Sn’., [11] 10, No. 6, 188 (1948). (30) R. G. Smith, Intern. Sugar J., 4, 430 (1902); R. G. Smith and T. Steel, J . SOC.Chem. Ind., 21, 1381 (1902).
296
W. W. BINKLEY AND
M. L. WOLFROM
present in final molasses.21 It is introduced by bacterial action. There are many types of bacteria that produce Dmannitol from carbohydrates, especially from D-fructose.al The occurrence of gross amounts of D-mannitol in damaged and bacterially infected cane has been described.a2 2 . Enzymes Hydrolyzing and color-producing enzymes or enzyme systems are active in raw cane juice and both contribute to the formation of molasses. The cane plant contains the sucrose-hydrolyzing enzyme invertasea2and thus differs from the sugar beet, where it is absent. This enzyme is present in the juice and produces a simultaneous decrease of sucrose and an increase in reducing sugars. The color-producing enzyme systems are represented by an oxidase (laccase), a peroxidase and t y r o s i n a ~ e . ~ ~ - ~ ~ These are oxidizing enzymes that produce phenols and quinones from aromatic compounds present in the plant juice which then react with ferric ion to produce dark colored complexes.
3 . Vitamins Raw cane juice is not a rich source of vitamins; it does contain a little vitamin A, some of the B vitamins and probably a trace of vitamin D.aa A more complete assay of the B-group vitamins revealed the presence of thiamine, riboflavin, pantothenic acid, niacin, and biotinSa7 Cane juice is a good source for the reported fat-soluble “antistiffness factor,” a yield of 0.1 g. (50,000,000 units) being obtained from 55 gal. of raw juice.s8 Application of counter-current distribution with a methanolisooctane system to a cane juice concentrate containing this “antistiffness factor ’) and sublimation of one of the three resulting fractions produced a sublimate with an infrared spectrum like ~ t i g m a s t e r o l . ~This ~ sterol has the same chemical and biological properties as the “antistiffness (31) H. R. Stiles, W. H. Peterson and E. B. Fred, J . Biol. Chem., 64, 643 (1925). (32) C. A. Browne, Jr., J . Am. Chem. SOC.,28,453 (1906); C. F. Walton, Jr., and C. A. Fort, Ind. Ens. Chem., 23, 1295 (1931). (33) M. Raciborski, Jaarverslag 1898 van het proefsta. voor Suikerriet West Java, 15 (1899). (34) F. W. Zerban and E. C . Freeland, Louisiana Agr. Expt. Sta. Bull. 106 (1919). (35) F. W. Zerban, Ind. Eng. Chem., 12, 744 (1920). (36) E. M. Nelson and D. B. Jones, J . Agr. Research, 41, 749 (1930). (37) W. R. Jackson and T. J. Macek, Znd. Eng. Chem., 36, 261 (1944). (38) J. Van Wagtendonk and Rosalind Wulzen, J . Biol. Chem., 164, 597 (1946). (39) H. Rosenkrantz, A. T. Milhorat, M. Farber and A. E. Milman, Proc. SOC. Exptl. Biol. Med., 70, 408 (1951).
COMPOSITION OF CANE JUICE AND CANE FINAL MOLASSES
297
myo-Inositol, a vitamin complement and growth factor, is present in relatively large quantities. It is generally included as a member of the B-group of vitamins although its position in human nutrition is still not adequately defined.41
4. Nitrogen Compounds Both simple and complex organic nitrogen compounds occur in cane juice. Loosely defined albumins and simpler proteins are the complex substances and they may represent as much as 25% of the organic nitrogen compounds of the juice.42 None of these proteins has been isolated or characterized. Analysis of a high-nitrogen juice (Florida) with ion-exchange resins showed that at least 75 % of the nitrogen substance behaved like amino a ~ i d s . 4 ~L(1evo)-Asparagine is the most abundant amino acid of cane juice, from which it has been isolated and ctdequately identified.44 L(deztro)-Glutamine and tyrosine were likewise isolated and identified44; the cane juice employed was Puerto Rican. Application of amino acid paper chromatography to the cations removed from cane juice by ion-exchange resins indicated the presence of leucine (or isoleucine), valine, y-aminobutyric acid, alanine, glycine, serine, asparagine, glutamic and aspartic acids, lysine and gl~tamine.4~~46 A preliminary chromatographic fractionation on clay enhanced the clarity of the spots, which were further identified by spot enhancement with authentic specimens of these substance^.^^ Tyrosine was detected only after a preliminary concentration on a column of powdered celluMicrobiological amino acid assays46 of the organic cationic fraction of a Florida cane juice showed l leu cine,^'-^^ 0.0025%; L-iso,~~ l e ~ c i n e , *0.0010%; ~ * ~ ~ ~ - v a l i n e ,0.0018%; ~ ~ * ~ ~ ~ - t r y p t o p h a n 0.0034%; (40) E. Kaiser and Rosalind Wulzen, Arch. Biochem. Biophys., 31, 327 (1951). (41) D. W. Woolley, J. Nutrition, 28, 305 (1944). (42) F. A. F. C. Went, Jahrb. wiss. Bolan., 31, 289 (1898); Chem. Zentr., 11, 367 (1898). (43) G. N. Kowkabany, W. W. Binkley and M. L. Wolfrom, Abstracts Papers 12th Intern. Congr. Pure Applied Chem., 166 (1951); Agr. Food Chem., 1, 84 (1953). (44) F. W. Zerban, 8th Intern. Congr. Pure Applied Chem., 103 (1912); Chem. Abstracts, 6, 3337 (1912). (45) 0. E. Pratt and L. F. Wiggins, Proc. Brit. West Indies Sugar Technol., 29 (1949); L. F. Wiggins and J. H. Williams, ibid., 40 (1951). (46) Performed by the Food Research Laboratories, Inc., Long Island City, N. Y., for the Sugar Research Foundation, Inc., New York, N. Y. (47) Method of S. Shankman, J . Biol. Chem., 160, 305 (1943). (48) Method of J. R. McMahan and E. E. Snell, J . Biol. Chem., 162, 83 (1944). (49) Method of R. D. Greene and A. Black, J . Biol. Chem., 166, 1 (1944).
298
W. W. BINKLEY AND M. L. WOLFROM
L-methionine,600.0009 %. L-Lysine, L-arginine, L-threonine, L-histidine and L-phenylalanine were sought but not d e t e ~ t e d . Although ~~~~~ qualitatively the general amino acid picture was always the same, the total amounts of amino acids in the top portions of Barbados cane varied with the variety from 1 to 12.5 millimoles per liter of cane juice; it was highest in the top and lower portions of the cane and was at a minimum near the middle. It was at a maximum in the early stages of
5 . Non-nitrogenous Acids Juice expressed from normal cane does not contain volatile acids; soured juice or juice from damaged cane possesses volatile acids, largely acetic.61 The principal organic acid of cane juice is aconitic. Its presence was based, as early as 1877,62on the isolation of a nearly pure specimen of the acid but proper identification was not recorded until 1919.63 The concentration of this acid in Louisiana juice solids varies from 0.3 to 1.6%and it may represent as much as 90% of the non-volatile acids.64 The occurrence in cane juice of such acids as malic,s6-6*suc~ i n iglycolic,6o ~ , ~formic,61 ~ ~ and ~ ~ ~ ~ ~ has been based only on qualitative tests and analytical methods. The recent application of a chromatographic p r o ~ e d u r eemploying ,~~ silicic acid, to an anionic fraction of cane juice has led to the isolation and identification of fumaric and succinic acids in addition to aconitic acid.'l6 Aconitic acid exhibits geometric isomerism and exists in cis and trans forms.66 These are interconvertible in solution, temperature and pH being factor^.^' It is (50) Method of J. L. Stokes, M. Gunness, Irla M. Dwyer and Muriel C. Caswell, J . Biol. Chem., 160, 35 (1945). (51) C. A. Fort and J. I. Lauritzen, Ind. Eng. Chem., Anal. Ed., 10, 251 (1938). (52) A. Behr, Ber., 10, 351 (1877). (53) C. S. Taylor, J. Chem. SOC.,110, 886 (1919). (54) R. T. Balch, C. B. Broeg and J. A. Ambler, Intern. Sugar J., 48, 186 (1946). (55) A. Payen, Compt. rend., 28, 613 (1849). (56) H. Winter, Z. Ver. deut. Zuckerind., 38, 780 (1888). (57) J. van Breda de Haan, Jaaruerslag 1891 van het proejsta. voor Suikerriet West Jaua, 9 (1892). (58) P. A. Yoder, J . Ind. Eng. Chem., 3, 640 (1911). (59) T. Tanabe, Repts. Tianan Formosa Ezpt. Sta., 4, 33 (1937). (60) E. C. Shorey, J . Am. Chem. Soc., 21, 45 (1899). (61) F. W. Zerban, J . Assoc. Of. Agr. Chemists, 16, 355 (1932). (62) J. E. Quintus Bosz, Arch. Suikerind., 28, 969 (1920). (63) H. C. Prinsen Geerligs, Arch. Suikerind. Nederland en Ned.-Indie, 1, 230 (1940). (64) C. S. Marvel and R. D. Rands, J . Am. Chem. doc., 72, 2642 (1950). (65) See Addendum, p. 314. (66) R. E. Miller and S. M. Cantor, Advances in Carbohydrate Chem., 6,231 (1951). (67) J. A. Ambler and E. J. Roberts, J . Org. Chem., 13, 399 (1948).
COMPOSITION OF CANE JUICE AND CANE FINAL MOLASSES
299
generally assumed that the natural form of aconitic acid is mainly cis because the enzyme system aconitase, widely distributed in plants and animals, converts citric acid to isocitric acid through the intermediate cis-aconitic acid. The pH of cane juice lies in the range 5.2-6.2 where the equilibrium would favor the ~is-forrn.~’
6. Pigments Normal cane juice, as it circulates in the intact plant, is colorless34; however, the tissue breakdown produced in grinding the cane for sucrose extraction permits the colloidal suspension and solution of pigmented substances not normally present. The tanninsa8 and water-soluble an tho cyan in^^^ are the major color contributors together with the colorproducing enzyme systems described previously (p. 296). One of the anthocyanins has been isolated from the rind of Purple Mauritius cane and converted with methanolic hydrogen chloride to a red-brown crystalit is a diglucoside and it possesses one line solid, CzsH33O17C1.4HzOB9; methoxyl group. Qualitative tests show that the aglycon is probably a mono-0-methyl-delphinidine. Chlorophyll is largely insoluble in the cane juice and is removed in the mill scums.34 That a small amount is soluble, however, is established by the chromatographic isolation of a green-colored fraction from final rn0lasses7~giving the ultraviolet absorption spectrum of chlorophyll a. An amorphous, incrustating solid, resembling lignin and designated “saccharetin ” is mechanically dispersed in the juice during the grinding of the cane. It is a water-insoluble, weakly acidic substance with the reported formula (C5H702),.7’ It dissolved readily in alkali to yield an intense yellow solution, gave a red color with phloroglucinol and hydrochloric acid, and an orange-yellow color with aniline sulfate and sulfuric acid. Dry distillation of “ saccharetin ” yielded pyrogallol; alkali fusion gave protocatechuic acid and pyrocatechol ; acid hydrolysis produced vanillic acid and vanillin. The lignin of bagasse has recently been isolated by an enzymic method and c h a r a c t e r i ~ e d . ~ ~ Anthocyanins, tannins and “saccharetin ” contain phenolic groups; their c,olor contribution is increased by the iron dissolved from the (68) F. W. Zerban, J . Znd. Eng. Chem., 10, 814 (1918). (69) C. J. Dasa Rao, D. G. Walawalkar and B. S. Srikantan, J . Indian Chem. Soc., 16, 27 (1938). (70) W. W. Binkley and M. L. Wolfrom, J . Am. Chem. Soc., 70, 290 (1948). (71) L. G . Langguth Steuerwald, Arch. Suikerind., 19,1543 (1911); Chem. Abstracts, 6, 691 (1912). (72) G . de Stevens and F. F. Nord, J . Am. Chem. Soc., 73, 4622 (1951); 74, 3326 (1952); 76, 305 (1953); Proc. Nail. Acad. Sn’. U.S., 39, 80 (1953).
300
W.
W. BINKLEY AND M.
L. WOLFROM
sugar mill and by the contact of air with the warm alkaline defecation solutions.T8
7. Waxes, Sterols and Lipids A small amount of the wax coating of sugar cane is dispersed in the juice during grinding. Extraction with petroleum ether will remove it from the raw j ~ i c e . 7 ~The wax and other similar substances are almost completely removed by the normal juice defecation and are found in the settlings (muds, filter-press cake) ; a minute quantity is carried through the entire process and is found in the final molasses (p. 311). The crude wax content of Louisiana whole cane is 0.2% and that of press cake may run to 22% (dry basis).16 Dried filter-press muds from the northern British West Indies islands and from Jamaica, Trinidad and British Guiana have an average wax content of 14.7, 11.3, 8.8 and 7.0%, respecti~ely.7~ Chromatography, on alumina, fractionated Louisiana cuticle cane wax (scraped from the stalk surface) into three groups: free acids, free alcohols and other substances (esters, ketones, hydrocarbons).77 Slight to almost complete hydrolysis occurred during the formation of these chromatograms. Identification of the individual components of the fractions was not completed. An empirical analysis of Louisiana cuticle cane wax is presented in Table I. TABLEI Chemical Data on Louisiana Sugarcane Cuticle Waxes7b
0
source
Saponification Value
Acid Value
Iodine Value
Acetyl Value
Corn290 Co5 281
40.5 56.7
18.0 23.8
8.0 15.6
91.8
-
Seedling variety from Coimbatore Experiment Stetion (India).
The nature of the non-acid fraction of the wax ia of interest.76 Some glycerol is present but the main alcohols are the higher-carbon monohydric alcohols, ceryl (n-C26Hsl-CH20H, isolated from Louisiana wax) and melissyl (isolated from Cuban molasses70). The latter is probably a (73) F. W. Zerban, Sugar Research Foundation, Tech. Rept. Series, 2 (1947). (74) N. G.Chatterjee, J . Indian Chem. SOC.,Ind. and News Ed., 8, 183 (1940). (75) R. T. Balch, Sugar Research Foundation, Tech. Rept. Series., 8 (1947). (76) L. F. Wiggins, Proc. E d . Wed Indiee Sugar Technol., 16 (1950). (77) T. W. Findley (with J. B. Brown), Ph.D. Dissertation, The Ohio State University, 1950.
COMPOSITION O F CANE JUICE AND CANE FINAL MOLASSES
301
mixture of n-CZSHss-CHtOH and n-Ca1Hss-CHz0H. The sterol content (free and combined) of Louisiana wax is in the range of 5-10%.76 The sterol fraction consists76 of 3 parts of stigmasterol (m. p. 171", [a], -51" in chloroform; acetate: m. p. 144",DI.[ -55" in chloroform) and 7 parts of a mixture of p-sitosterol and 7-sitostierol (m. p. 137-143", [.ID -38" in chloroform).
8. Inorganic Components Crusher juice and whole raw cane juice contain representative i riorganic constituents; clarified juice is limed. The inorganic substances TABLEI1 Inorganic Components of Juice from Louisiana-grown Cane Varieties Coimbatore 281 and %lo78
Co. 981a
Co. 29O0
KaO NanO CaO MI30 Alz08 FeaOs MnO
1.603% 0.060 0.216 0.248 0.088 0.0104 0.0034
1.792% 0.056 0.189 0.263 0.067 0.01 0.0031
SO8
0.543 0.415 0.191 0.094
0.455 0.400 0.246 0.096
Component
PaOs
c1
SiO2 Expraasad ran per cent on aolid~.
or ash contents vary greatly among the different varieties of cane within a confined area and in a single variety grown in the different cane producing areas. The principal cations of cane juice are potassium, magnesium, calcium, aluminum, sodium, iron and manganese; anions are sulfate, phosphate, chloride and silicate (Table 11). Raw juice contains more inorganic cations than inorganic anions even though it is acid, pH 5.2-6.2; this acidity is due to the presence of organic acids. 9. Summary
Table 111 summarises the data on cane juice constituents. (78) C. A. Fort and N. McKaig, U . S. Dept. Agr., Tech. Bull. 688 (1939).
302
W. W. BINKLEY AND M. L. WOLFROM
TASLE~ I11 Cane Juice Constituents Component Carbohydrates Sucroie D-Glucose D-Fructose myo-Inositol Phytin Pentosans Methoxyl Pectins Uronic acids Starch Organic phosphate Enzymes Invertase Oxidase Peroxidase Tyrosinase Vitamins Vitamin A Biotin Vitamin D (?) Niacin Pantothenic acid Riboflavin Thiamine Nitrogen compounds Amino acids Alanine 7-Aminobutyric acid L(leoo)-Asparagine Aspartic acid Glutamic acid L(deztro)-Glutamine Glycine dsoleucine *Leucine Lysine L-Methionine Serine *Tryptophan Tyrosine L-Valine
Juice origin" La.
}
La. La. Cuba Trin. La. Trin. La. La. Cuba
Concentration, % 78-84 4.3-7.8
78 78
0.041
21 21 11 15 11 15 18 25
-
0.04-0.07 0.08 0.0-0.1 0.44 0.012-0.018 0.0187
La. La. La. *La. La. La. Cuba La. La. Cuba La. Cuba La. Cuba La. Cuba
Reference
32, 34 34 34 34 2.2 x 10-6 17.6 x 10-6
36 37 37
4.9 x 10-6 4..5 x 10-6 218 x 10-6 99.4 x 10-6 3.1 X 4.9 x 10-6 5.3 x 10-6 10.5 X 10-6
36 37 37 37 37 37 37 37 37
-
Barb. 1 - 12.5 X lO-'JM 45 Fla., Jam. 43,45 Fla., Jam. 43,45 Fla., P. R., Jam. 4345 Fla., Jam. 43,45 Fla ., Jam. 43,45 Fla., P. R., Jam. 4345 Fla., Jam. 43, 45 Fla. 0.0010 46 Fla. 0.0025 46 Jam. 45 Fla. 0.009 46 Fla., Jam. 43, 45 Fla. 0.0034 46 Fla., P. R. 43, 44 Fla. 0.0018 48
COMPOSITION O F CANE JUICE A N D CANE FINAL MOLASSES
303
TABLEI11 (Continued) Component Proteins Non-nitrogenous acidsa6 Aconitic Fumaric Glycolic Malic Oxalic Succinic Pigments Anthocyanins Chlorophyll “Saccharetin ” Tannins Waxes, sterols and lipids Nonsaponifiable fraction Palmitic acid Oleic acid Linoleic acid Linolenic acid Inorganic components
Java La. La. Trin. La. La. Hawaii Java
b
0.33-0.49 1.79-3.48 0.6-1.2 0.3-2.1
-
La. La. Trin. La. La., Cuba La. La. La., Trin. La. La. La. La. La. La. Trin.
Barb. = Barbados; Fla. = Florida; Jam. = Jamaica; La.
Trin. = Trinidad.
Concentration, %’
Juice Origin”
-
0.73-1.58
-
0.73-1.58 38. Qb 16.96 9.16 31 .4b 1 .Ob 2.6-3.6 1.2-3.0
-
Reference 42 78 78 79 54, 65 65 61 55-58 55,62,63 65 79 34 34, 70 34 68 78, 79 75 75 75 75 75 78 79
Louisiana; P. R. = Puerto Rico;
Percentage of crude cane wax from press oake.
111. COMPOSITION OF CANE FINALMOLASSES During the production of sucrose from cane juice, crystallization inhibitors collect in the residual sirups or mother liquors; these sirups are called molasses. When the accumulation of these inhibitors is so great that the recovery of sucrose is no longer economically feasible, this molasses is known as the final or blackstrap molasses. The term “blackstrap” originated in the Dutch sugar industry from black “stroop” meaning black sirup.80 The molasses obtained in the early stages of sucrose production has a pleasant, palatable flavor and is used in the preparation of edible molasses. While some molasses intermediate between edible and blackstrap are best suited for the production of calcium magnesium aconitate,81far more aconitate is recovered from blackstrap (diluted t o 55’ Brix) which is available all year. In the recrystalli(79) F. Hardy, PZanter Sugar Mfr., 70, 445 (1927). (80) Noel Deerr, Intern. Sugar J . , 47, 123 (1945). (81) L. Godchaux, 11, Sugar J., 10, 2 (1947).
304
W. W . BINKLEY AND M. L. WOLFROM
zation or refining of the crude sucrose, the final mother liquor concentrate is known as refinery blackstrap molasses. I t can be considered as consisting of the accumulated blackstrap molasses originally adherent to the crude sucrose crystals. I n the crystallization of sucrose from cane juice, the pH of the normal juice entering the process lies in the range 5-6. This juice contains a little water added during the crushing process. Calcium hydroxide is added to bring the pH to 8 f 0.5 and the mixture is heated to 220°F. and maintained around 200°F. for several hours. This is the defecation process and resdts in a clarification of the liquid with the precipitation of suspended materials, proteins, waxes and fats.81a It is closely controlled and varies slightly with the processor. After passing through the settlers the pH is now approximately 7. The muds from the settlers are removed with continuous rotary filters, resulting in filter cake. The clarified juice is heated to 225°F. in the first of a bank (usually four) of multiple-effect vacuum evaporators for a period of ten minutes or less and for longer periods at lower temperatures in subsequent evaporators as the juice is concentrated to a sirup. The crystallization of sucrose from this sirup is a batch operation and is accomplished with single vacuum evaporators (“pans ”). During these processes the mother liquors are recirculated and fresh defecated juice is added. The final residual sirup is blackstrap molasses; its pH is 5.8. 1. Carbohydrates
As in cane juice, sucrose is the principal sugar of cane blackstrap molasses. However, the ratio of sucrose to apparent reducing sugars has dropped from 10-15: 1in the juice to 1.5-2.5: 1 in the molasses. Patents have been issued for the recovery of sucrose from molasses but general acceptance of these processes by the industry is still lacking. Some of the methods depend on the removal from molasses of the reducing sugars and other impurities by lime,82invertase-free yeast,83 barium hydroxide,8* or fuller’s earth clay.86 Other methods are based upon the use of solventsseand of ion-exchange resins. ST The significant simple sugars are (81a) P. Honig, Sugar, 47, No. 6,31 (1952). (82)E.E.Battelle, U. 5. Pats. 1,044,003(1913),1,044,004(1913). (83)H.De F.Olivarius, U. S. Pats. 1,730,473 (1929),1,788,628(1931). (84)A. L. Holven, U. S. Pats. 1,878,144(1933),1,878,145(1933). (85) M. L. Wolfrom and W. W. Binkley, U. S. Pat. 2,504,169 (1950);J . Am. Chem. SOC.,69, 664 (1947). (88) J. H. Payne, U. S. Pat. 2,501,914(1950). (87) N. V. Octrooien Maatschappij, Dutch Pat. 68,496 (1946); Chem. Abdracts. 41,4667 (1947).
COMPOSITION
OF CANE JUICE
AND CANE FINAL
MOLASSES
305
D-glucose and D-fructose. The actual isolation of crystalline D-glucose was accomplished by the chromatography of Cuban blackstrap molassesss on fuller’s earth claysg;D-fructose was obtained as a sirup which yielded crystalline acetates of the B-D-pyranose and keto forms of this sugar after acetylation and chromatographyg0on magnesium acid silicate. The precipitation from molasses of D-mannose as its phenylhydraeone was reported over 50 years Recent investigation of the phenylhydrazone from Cuban molasses did not reveal any D-mannose phenylhydrazoneg2;the presence of this sugar in cane molasses cannot be considered as demonstrated. Early investigatorsgs considered an unestablished sugar designated “glutose” to be an unfermentable, molasses component and to be isolable from this unfermentable residue as its phenylosaeone. Later workg4showed that “ glutose phenylosaeone ” was an impure D-glucose phenylosazone. The presence of D-psicose (D-rib-hexdose, D-allulose) in distillery slop (from the fermentation of cane molasses) is claimed,g5but sharp experimental support is lacking. Diheterolevulosans (difructose dianhydrides) are obtained by refluxing concentrated aqueous solutions of ~ - f r u c t o s e . ~ Chromatography ~~~~ of Cuban blackstrap molasses in a pilot-plant-scale chromatogram on fuller’s earth clay did not reveal the presence of these s u b s t a n ~ e s . ~ ~ Traces of the complex carbohydrates contained in the juice survive the processing and appear in the molasses; analytical data indicate that they probably consist largely of pectins and pentosans. lo Quantitative estimations based on the ash-free solids of Louisiana molasses revealed the presence of 2% uronic acids and 0.5% methoxyl.16 Heat-modified (88) W. W. Binkley and M. L. Wolfrom, J . Am. Chem. SOC.,73, 4778 (1950). (89) B. W. Lew, M. L. Wolfrom and R. M. Goepp, Jr., J. Am. Chem. SOC.,68, 1449 (1946). (90) W. H. McNeely, W. W. Binkley and M. L. Wolfrom, J. Am. Chem. SOC., 67, 527 (1945). (91) C . A. Lobry de Bruyn and W. Alberda van Ekenstein, Rec. trav. chim., 16, 260, 280 (1897). (92) M. Grace Blair (with M. L. Wolfrom), Ph. D. Dissertation, The Ohio State University, 1947. (93) H. C. Prinsen Geerligs, Intern. Sugar J., 40, 345 (1938). Review article. (94) L. Sattler, Advances in Carbohgdrate Chem., 3, 113 (1948). (95) F. W. Zerban and L. Sattler, Znd. Eng. Chem., 34, 1180 (1942). (96) L. Sattler and F. W. Zerban, Znd. Eng. Chem., 37, 1133 (1945). (97) M. L. Wolfrom and M. Grace Blair, J. Am. Chem. SOC.,70, 2406 (1948). (98) W. W. Binkley and M. L. Wolfrom, Sugar Research Foundation, Member Rept. 26, 21 (1950).
306
W. W. BINKLEY AND M. L. WOLFROM
starches are probably contained in the molasses from the starch-bearing cane juice^.^^^^^ Crystalline myo-inositol (see p. 294) was isolated from Cuban final molasses by chromatography on fuller's earth clay.ss The myo-inositol content (0.261%) of this molasses was determined by fermentation with yeast, acetylation of the unfermented residue, chromatography on magnesium acid silicate of the acetylated residue and the isolation of crystalline myo-inositol hexaacetate. The value obtained by bioassay was 0.238%.21 The phytin content of Cuban molasses was estimated to be 0.22-0.23% by bioassay.21 A small amount of D-mannitol as the crystalline hexaacetate was obtained from this molasses by these chromatographic procedures.88 I n addition to the D-mannitol produced by the bacteria in the sugar mill, this hexitol may be introduced bacterially in the cane juice, thus leading to its accumulation in the final molasses. Extension of these chromatographic techniques to the unfermented residue of Cuban molasses led to the isolation of erythritol and D-arabitol (as their respective acetates) as trace constituentsss; the yeast may be the source of these substances. Another important carbohydrate group of cane final molasses, and one which has been little studied, consists of the products formed by the action of heat, alkali and amino acids upon the reducing sugars. This is sometimes termed the non-fermentable fraction as it remains after yeast fermentation although it is thereby badly contaminated with metabolic products from the yeast. The reducing sugars D-glucose and D-fructose are first formed by the action of invertase on sucrose. These are then subjected to the action of hot alkali (pH ca. 8) during the defecation and to considerable heat treatment a t pH 6-7 thereafter (see p. 304). Monosaccharide decomposition involving dehydration, disproportionation, and fragmentation, is involved. Dehydration leads necessarily to dicarbonyl compounds99~100 which are probably significant reaction intermediates and may form furan derivatives (Fig. 1 and Sections 111-4 and 111-5). Chain fragmentation by reverse aldolizationlol may play a part (Fig. 1 and Section 111-4). In addition, the amino acids present undoubtedly react with the reducing sugars, or their dehydration products, to yield dark colored polymeric substances containing nitrogen. This is known as the Mail(99) M. L. Wolfrom, E. G. Wallace and E. A. Metcalf, J. Am. Chem. SOC.,64,265 (1942). (100) M. L. Wolfrom, R. D. Schuetz and L. F. Cavalieri, J. Am. Chem. SOC.,71, 3518 (1949). (101) J. F. Haskins and M. J. Hogsed, J . Org. Chem., 15, 1275 (1950).
COMPOSITION OF CANE JUICE AND CANE FINAL MOLASSES
307
lard102 or “browning” rea~tion.1~3-1~6It leads to the production of color and finally to the separation of brown to black solids known as “ melanoidins.” O=? HO'H3
HO'
+
HO'H3
*?
7
3*
0=3H
H?oH
HofH
H03H
Hof
=
?
Ho?H H OH=
Ho?H
HozHf
HO~H
Ho'H?
HO'HHQ
Ho?H 0=3H
f
H OH= HO~H
HO'HHQ
I H03H
HofH H?oH
Ho?H -0OH HO'H?
y' HO? 0=3H
0=3H
0=3H
HP
0=3
zHf
0=3
I
I
OEH-
H3-H3 O=g-f
HY-'H30H
/ O\
+-
p
HozHP
OKH-
Ho?H H0;7H
1
HO'H3
Hay
HozH7
These various products of sugar decomposition are reducing88*10s so that the consideration of this analytically measurable property as being due solely to D-glucose and D-fructose is in error. Their total content has been estimatedlo7to be 10.1 and 10.7% of the solids in final molasses samples from Louisiana and Cuba, respectively. This fraction was separated by clay chromatographyss and its more complex components were segregated by dialysis and freeze-drying. The product so obtained was a brown, bitter, non-hygroscopic solid that contained nitrogen (1.7 %) and exhibited a slight Fehling reduction. The major fraction of the (102) L.-C. Maillard, Compt. rend., 164, 66 (1912); Ann. chim., [9] 6, 258 (1916). (103) J. P. Danehy and W. W. Pigman, Advances in Food Research, 3, 241 (1951). (104) M. L. Wolfrom, R. C. Schlicht, A. W. Langer, Jr., and C. S. Rooney, J . Am. Chem. Soc., 76, 1013 (1953). (105) L. Sattler and F. W. Zerban, Znd. Eng. Chem., 41, 1401 (1949). (106) C. Erb and F. W. Zerban, I d . Eng. Chem., 39, 1597 (1947). (107) C. A. Fort, Sugar, 41, No. 11, 36 (1946).
308
W. W. BINKLEY AND M. L. WOLFROM
material when subjected to dialysis passed through the membrane in the manner of relatively low molecular weight substances.108 2. Vitamins The desugaring of cane juice concentrates the heat- and alkali-stable vitamins in the final molasses. Even after this accumulation, only mgo-inositol may have reached the level of minimum dietary requirem e n t ~ . ’ Niacin, ~~ pantothenic acid and riboflavin are also present in significant quantities109;the thiamine, pyridoxin, pantothenic acid, biotin and folic acid contents of molasses have been estimated by bioassay.llOslll The biotin content of Hawaiian and Cuban molasses was 2.1 and 1.7 gammas per gram, respectively.112 The “antistiffness factor” (closely related to stigmasterol) has been found in cane m o l a s ~ e s . The ~~~~~ distillery slop from the yeast fermentation of molasses is marketed as a vitamin concentrate; this product also contains vitamins originating in the yeast.
3 . Nitrogen Compounds The nitrogen content of the cane blackstraps of North America varies between 0.4 and 1.4%. A surprisingly large fraction, as much as 60-70%, of this nitrogen is present in a relatively simple form.43*113 Isolations based on identified crystalline products, obtained from Hawaiian molasses with the aid of ion-exchange resins, are recorded113 for aspartic acid (as the free acid), glutamic acid (as the hydrochloride), lysine (as the picrate) and the purines guanine (as the hydrochloride) and xanthine (as the free base); qualitative tests were obtained for hypoxanthine and the pyrimidine 5-methyl-cytosine. Aspartic and glutamic acids occur in the plant mainly as their amides asparagine and glutamine but in the mill processing these are hydroly~edwith the evolution of ammonia. The amino acids from Florida molasses were concentrated on fuller’s earth clay and were resolved by paper chromatography employing spot enhancement with known specimens43;the presence of asparagine, aspartic acid, glutamic acid, y-aminobutyric acid, alanine, glycine, leucine or isoleucine, and valine were so established. Albumins and other protein-like substances of cane juice are precipi(108)W. W.Binkley and M. L. Wolfrom, unpublished results. (109)R: C. Hockett, J . California State Dental Assn., 26, No. 3 Suppl., 72 (1950). (110) D.Rogers and M. N. Mickelson, Znd. Ens. Chem., 40, 527 (1948). (111) W.A. Krehl and G. R. Cowgill, unpublished results. (112) E. E. Snell, R. E. Eaken and R. J. Williams, J . Am. Chem. Soc., 62, 175 (1940). (113)J. H. Payne with R. F. Gill, Jr., Hawaiian Planters’ Record, 60, No. 2, 69 (1946).
COMPOSITION OF CANE JUICE AND CANE FINAL MOLASSES
309
tated during defecation and only traces of them reach the final molasses. The principal bearers of complex nitrogen are the molasses “browning” products mentioned in the preceding section.
4. Non-nitrogenous Acids Aconitic acid was the first organic acid properly established as a component of cane molasses.63 Louisiana molasses is a rich source and contains more than 6% of this acid in some ca~es.1~4With a potential annual harvest of over 5,000,000 pounds of aconitic acid from Louisiana alone, it is nevertheless only recently that the commercial production of this acid from molasses has been initiated in Louisiana.l16 Its isolation depends upon the insolubility and ready crystallizability of dicalcium Final, or an intermagnesium trans-aconitate hexahydrate. 114,116-118 mediate or “ B ” , molasses is diluted to 55% solids (55” Brix) with the appropriate wash water from the process (see below) and the pH is adjusted to 7 with lime. The solution is heated to 200°F. and calcium chloride is added. Heating is continued for forty-five minutes whereupon the precipitate is collected. It is resuspended a t 195°F. in a volume of water sufficient to adjust the next lot of molasses to 55” Brix. The precipitate is again centrifuged; it contains about 56% aconitic acid.l16 Aconitic acid, either as such or after conversion to itaconic acid, is of present-day commercial interest. llsa Malic and citric acids have been adequately identified from molasses as their crystalline h y d r a ~ i d e s . ~It~is~ probable that at least the former is a normal juice constituent. Lactic acid was identified as its zinc salt in molasses11g;it arises from bacterial action. Formic acid is presentllg; it probably has an origin, at least in part, in sugar decomposition. Acetic and propionic acids are components and their amounts serve as a rough index of the activity of the microorganisms introduced into the molasses. The microbial count of cane juice, molasses and related products has been determined (Table IV). Application of modern ion-exchange and silica-gel chromatographic techniques to cane distillery slop (cane molasses yeast fermentation (114) R. T. Balch, C. B. Broeg and J. A. Ambler, Sugar, 40, No. 10, 32 (1945); 41, No. 1, 46 (1946); see Ref. 133. (115) L. Godchaux, 11, Sugar J., No. 4, 3 (1949). (116) E. K. Ventre, J. A. Ambler and S. Byall, U. S. Pat. 2,359,537 (1944). (117) J. A. Ambler, J. Turer and G. L. Keenan, J . A m . Chem. Soc., 87, 1 (1945). (118) E. K. Ventre, U. S. Pat. 2,469,090 (1949). (11%) R. N. Evans, Abstracts Papers Am. Chem. Soc., 119, 3Q (1951). (119) E. K. Nelson, J . Am. Chern. SOC.,61, 2808 (1929). (120) C. H. Millstein, L. C. Tobin and C. S. McCleskey, Sugar J., 3, No. 9, 13 (1941).
310
W. W. BINKLEY AND M. L. WOLFROM
residue) led t o the isolation of crystalline aconitio acid as the major organic acid component.B6 The steam distillation of acidified cane distillery slop yielded formic and acetic acids ; they were identified by qualitative tests. 121 Esterification and ester distillation followed by the formation of crystalline hydrazides led t o the adequate identification of succinic, tricarballylic and perhaps citric as component acids.lal Ether extraction of diluted acidified slop and fractional precipitation in aqueous ethanol of the barium salts of the extracted acids placed succinic and TABLEIV
Microbial CounP of Sugar Mill Products‘s0
Raw juice Clarifier effluent Press juice Evaporator sirup Storage tank sirup Crystallizer contents Masseouite Raw sugar Molaaaes a
Number of bacteris per ml.
Thermophiticc Bacteria
Mesophili@ Bacteria
Product
Low 8,000,000 0 0 200
1,300 2,000 1,200 340 300 a
High 750,000,000 11 51,000 3,300 7,100 44,000 10,600 5,100 310.OOO
Optimal growth at 15-4CPC.
Low 14 0 3,700 300 16,100 350 1,700 100 1.200
High 170 8 250,000 15,500 38,500 15,000 17,100 2,200 16.500
O p t i d growth at 40-600C.
tricarballylic with a trace of aconitic acids in the precipitate and lactic acid (isolated as the crystalline zinc salt) in the supernatant liquor.121 Other acids (often as esters) have been found in fermented molasses. Usually these substances are products of bacteriological action and they are not normal constituents of unfermented molasses. “Bauer ” oil from the yeast fermentation of Cuban blackstrap consists chiefly of the ethyl esters of capric, lauric, myristic and palmitic acids.lZ2 The fat from the scums of hot-room Louisiana molasses contained hexanoic (caproic) and octanoic (caprylic) acids.10 The occurrence of such volatile acids as propionic, lZ3b ~ t y r i c ~ and * ~ Jvaleric ~ ~ acids124 requires more adequate establishment. Qualitative tests showed the probable presence of 5(hydroxymethyl)2-furaldehyde, acetoin, levulinic and formic acids, and methylglyoxal (121) E.K. Nelson and C. A. Greenleaf, Znd. Eng. Chem., 21,857 (1929). (122) C. S. Marvel and F. D. Hager, J . Am. Chem. SOC.,46,726 (1924). (123) N. Srinivasan, Intern. Sugar J., 41, 68 (1939). (124) E.Humboldt, Facts About Sugar, 96, 18 (1930).
COMPOSITION OF CANE JUICE AND CANE FINAL MOLASSES
311
(or acetol) in the volatile decomposition products from the unfermentable residue of a heated D-fructose solution'os; these are sugar decomposition products. The volatile products from a fermented sucrose mixture contained small quantities of acetylmethyl carbinol. lo 5. Pigmented Materials
The principal pigmented substances of final molasses are probably the complex products of the reaction between the reducing sugars and the amino-containing components of the cane juice (see Section 111-1). The reducing-sugar self-decomposition in the presence of organic anions, especially aconitate, is probably also a factor and here the anion may serve principally as a buffer and probably does not enter into reaction with the reducing sugar or with its decomposition products. Model experiments126at pH 8 indicate that the main chemical color-producing system in molasses is that of D-fructose and D-glucose with asparagine followed by that of D-fructose and D-glucose in the presence of aconitate ion. Concentrated aqueous solutions of D-fructose heated at sugar mill temperature will produce a dark colored solution in the absence of amino a ~ i d s . ~ ~ , ~ ~ The polyphenolic colored substances of cane juice, largely tannins and an tho cyan in^,^^ form even more intensely colored iron complexes. Some of these compounds survive defecation and darken further with prolonged exposure to air and ferric ion a t elevated temperatures. Virtually pure chlorophyll a was isolated from Cuban molasses by chromatographic and extraction proceduresT0;it was identified by its absorption spectrum; its estimated concentration was 0.00005%. 6. Waxes, Sterols and Lipids
The concentration of fats and related substances in molasses is low; analytical values depend on the extracting solvent.126 These tenaciously retained materials can be removed by fractionation of blackstrap on fuller's earth clay.?O Chromatography on a calcium silicate of the fat fraction of Cuban molasses led to the isolation of melissyl alcohol, a phytosterol fraction, chlorophyll a and a fat fraction containing a glyceride of linoleic acid.'O Stigmasterol and syringic acid are reported as ether-extractable constituents of molasses.127 (125) J. N. Schumacher (with M. L. Wolfrom), M. Sc. Thesis, The Ohio State University, 1952. (126) C. F. Bardorf, Can. Chem. Met., 11, 231 (1927). (127) S, Takei and T. Imaki, Bull. Znst. Phys. Chem. Research (Tokyo), 16, 1055 (1936).
312
W..W. BINKLEY AND M. L. WOLFROM
7 . Odorants The ether extract of cane molasses yields an acidic substance with the characteristic odor of raw sugar.128 The steam distillation of molasses is stated to yield a “rum Fractionation of cane final molasses on fuller’s earth clay produces a concentrate with a strong molasses 0dor.7~ The infrared spectra of the volatile portion of this concentrate indicated the absence of hydroxyl and carbonyl and the presence of a substituted benzene structure, of paraffinic methylene and methyl groups, of an acetate group, and of the > C=C < and -C=Clinkages. The presence of a sulfur function is probable. Further chromatography indicated complexity in this volatile c ~ n c e n t ra t e.’~~ The deionized unfermentable (by yeast) residue from Cuban final molasses has a raisin-like odor.21 8 . Inorganic Components
The mineral constituents of the raw cane juice persist in the final molasses. The principal difference in relative amounts of these substances in molasses arises from the use of lime in defecation which causes an increase in calcium. Egyptian cane molasses solids contained 0.66% of titanium.131 The cations are believed to complex with the sugars and to thus inhibit the crystallization of sucrose, which latter is known to form compounds with inorganic salts, such as its well known compound with sodium chloride. Decationization of cane juice with ion exchange resins greatly reduces molasses formation but sucrose inversion is a concomitant problem. 192 9. Summary
Table V summarizes the data on the constituents of cane final molasses. (128) S. Takei and T. Imaki, Bull. Znst. Phys. Chem. Research (Tokyo), 16, 124 (1936). (129) E. Arroyo, Univ. Puerto Rico Agr. Expt. Sta. Research Bull. 6 (1945); D. KervBgant, “Rhums et eaux-de-vie de came,” Lea Editions du Golfe, Vannes, France, 1946. (130) M. L. Wolfrom, W. W. Binkley an&IFlorinda 0. Bobbio, El Crisol, i n press (1953). (131) E. 0. von Lippmann, Ber., 68, 426 (1925). (132) J. H. Payne, H. P. Kortachak and R. F. Gill, Jr., Ind. Eng. Chem., 44, 1411 (1952).
313
COMPOSITION OF CANE JUICE AND CANE FINAL MOLASSES
TABLEV Cane Final Molasses Constituents Component
Carbohydrates Sucrose Reducing sugars " D-Glucose D-Fructose myo-Inositol Phytin D-Mannitol Uronic acids Methoxyl Sugar "reaction products" Vitamins Biotin Folic acid Nicotinic acid Pantothenic acid Pyridoxine Riboflavin Thiamine Nitrogen Compounds Total nitrogen
Amino Acids Alanine 7-Aminobutyric acid Asparagine Aspartic acid Glutamic acid Glycine Leucine (or isoleucine) Lysine Valine Nucleic acid bases Guanine Hypoxanthine 5-Methylcytosine Xanthine
Molasses Origin"
Concentration, Reference
%'
La. Cuba La. Cuba La. Cuba Cuba Cuba Cuba Cuba Cuba La. La. La. Cuba
80.52b 78.90b 37.39 47.28 32.72 20.98 6.9 1.6 0.261 0.225 0.6 2.0 0.8 10.1 10.7
107 107 88 88 21 21 21 15 15 107 107
Cuba Cuba Cuba Cuba Cuba Cuba Cuba
17.0 X 0.43 X 222 x 635 X 19.1 x 24.4 X 8.5 X
111 111 111 111 111 111 111
Cuba Fla. Hawaii La. P. R. Fla. Fla. Fla. Fla., Hawaii Fla., Hawaii Fla. Fla. Hawaii Fla. Hawaii Hawaii Hawaii Hawaii
0.89 1.40 0.71 0.38 1.16
-
-
-
-
107 107 107
107
10-6 lo-& 10-6
lo-'
108 108 108 108 108 43 43 43 43, 113 43, 113 43 43 113 43 113 113 113 113
314
W. W. BINICLEY AND M. L. WOLF’ROM
TABLBV (Continued) Molasses Origin“ Cuba La. La. P. R. P. R. P. R. P. R. P. R. P. R.
Component Non-nitrogenous acids
Aconitic Malio Citric Formic Lactic Acetic Bacteria Mesophilic Thermophilic Pigments Chlorophyll a “Browning products” Tannins Anthocyanins Waxes, sterols and lipids Melissyl alcohol Phytosterol Stigmasterol Syringic acid Odorants Molasses odor fraction Inorganic components
-
Concentration, %7
7.59 7.39 4.95 0.95
-
0.12 0.60 0.24
Reference 107 107 133 119 119 119 119 119 119
La. La.
300-310,0OOc 1,200-16,5OOc
120 120
Cuba La., Cuba La. La. Cuba Cuba Cuba Formosa ( 1 ) Formosa (?)
5 x 10-6 10.1-10.7
70 107 34 34 70 70 70 127 127
-
0.50 -
-
Cuba, Hawaii La. 13.46d Cuba 13. 76d
6 Fla. = Florida; La, = Louisiana; P. R. Puerto Rioo. ber of bacteria per ml. of molasses. d Carbonate ash.
b
70, 130 107 107
Total aotids in the molasses.
Num-
ADDENDUM
Non-nitrogenous Acids in Cane Juice Application134to Louisiana cane juice of the procedure of Ramsey and Patterson,136as modified by Marvel and Itands,64 leads to the following acid assay: aconitic, 2.07 % ; malic, 0.28% ; citric, 0.22%; mesaconic, 0.058%; succinic, 0.04%; fumaric, 0.023 %; glycolic, oxalic and an unknown acid, present. WigginszbShas tentatively identified, by paper chromatography, succinic, malic, aconitic, citric, glycolic, and possibly glyoxalic acids. (133) C. A. Fort, B. A. Smith, C. L. Black and L. F. Martin, Sugar, 47, No. 10, 33 (1952). (134) E. J. Roberts, C. A. Fort and L. F. Martin, Abstracts Papers Am. Chem. SOC.,124, 1OD (1953). (135) L. L. Ramsey and W. I. Patterson, J . Assoc. Ofic. Agr. Chemists, 28, 644 (1945).
SEAWEED POLYSACCHARIDES
BY T . MORI* Tokyo University. Tokyo. Japan
CONTENTS I . Introduction . . . . . . . . . . . . . . . . . . . . . . . I1. Agar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . 316
317 318 b cGalactose. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318 c . 3,6-Anhydro-~-galactose. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319 d . Ester Sulfate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323 e . Other Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323 2. Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323 I11 . Mucilage of Dilsea Edulis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328 1. Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328 2. Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 IV . Carrageenin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330 1. Cold-water Extract and Hot-water Extract . . . . . . . . . . . . . . . . . . . . . . . . . 330 a Physical Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331 b . Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332 2. Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333 a . D-Galactose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333 b . IcGalactose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333 c. “Ketose” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333 d . D-GIucose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334 e . 2-Keto-~-gluconicAcid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334 f . Pentose and Methylpentose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334 g . Summary of Carbohydrate Constituents . . . . . . . . . . . . . . . . . . . . . . . 335 h . Ester Sulfate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335 3. Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4. Hydrolytic Enzymes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339 V. Fucoidin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340 1. Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340 2. Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341 VI . Laminarin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344 . . . . . . . . . . . . . . . . . . . . . . . 344 1. Composition . . . . . . . . . . . . . . . . . . 2. Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345 3. Hydrolytic Enzymes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 ............................................ ............................................
.
.
* Contribution from the Laboratory of Fisheries Chemistry of the Faculty of Agriculture of the University The writer wishes to express his sincere thanks to Professor M . L Wolfrom for his kind revision of the manuscript; to D r Kimiko Anno for checking the references; and to D r E Kylin and to Professors V . C . Barry, T. Dillon and C . Araki for sending reprints of their publications . 316
.
.
. .
.
316
1. MORI
VII. Other Polysaccharides. . . . . . . . . . . . 1. Mucilage of Dumontia Incrassatas . . . . . .. . . . . . . . . . . . ... 347 2. Algal Cellulose ...................... 348 3. Algal Xylan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4. Alginic Acid.. . . . . . ........................ 349 5. Floridean Starch.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6. Cyanophycean Starch.. .......................... 350
I. INTRODUCTION Seaweeds are classified into four groups: the Chlorophyceae or green algae; Phaeophyceae or brown algae; Rhodophyceae or red algae; and Cyanophyceae or blue-green algae. Of these, Phaeophyceae and Rhodophyceae are the more significant from the viewpoint of output and utilization. The major components of seaweed are carbohydrate in nature and thus the use of seaweed in food and industry is due t o its carbohydrate content and especially t o such polysaccharides as agar, algin, carrageenin and funorin’ (the polysaccharide of Gloiopeltis). In some cases seaweed is utilized for the manufacture of iodine and potassium chloride. Chemical studies on seaweed have centered mainly on their carbohydrates, especially those of Phaeophyceae and Rhodophyceae where material is in good abundance. Seaweed polysaccharides may be differentiated into reserve polysaccharides, such as laminarin and Floridean starch, and structural polysaccharides. Except for cellulose, the latter are mainly mucilages serving as membrane-thickening materials. Examples of these are algin, carrageenin, fucoidin and funorin. With the exception of algin, these mucilage polysaccharides are characterized by their combined sulfate content, first reported by Ham2 in carrageenin. Little progress in knowledge of the structure of these polysaccharides was made until Percival and Somerville3 succeeded in methylating agar and isolating 2,4,6-trimethyl-~-galactose, proving that D-galactopyranose units are joined C1-+ C3. This was also the first demonstration that D-galactopyranose units could form such a polysaccharide linkage. Thereafter many studies have been carried out on seaweed polysaccharides by Percival and by other investigators. Nevertheless, the structure of none of the polysaccharides is fully clarified. This is due t o their complexity, caused by the presence of several sugars and, save for algin and laminarin, of combined or ester sulfate. A carbohydrate sulfate ester is difficult to manipulate experimentally because of the extreme ease with which it (1) C. K. Tseng in “Colloid Chemistry” (J. Alexander, editor), Rheinhold Publishing Corp., New York, 1946, Vol. VI, p. 629. (2) P. Haas, Biochem. J . , 16, 469 (1921). (3) E. G. V. Percival and J. C. Somerville, J . Chem. Soc., 1015 (1937).
SEAWEED POLYSACCHARIDES
317
undergoes desulfation and carbonization in acid media. Although the difficulties are formidable, the elucidation of the structure of these polysaccharides is a desirable objective. We may include among these polysaccharides the substance fucoidin, recently discovered by Vasseur' in the jelly coat of the sea-urchin.
11. AGAR In Florideae, one of the subclasses of Rhodophyceae, the cell wall is composed of an inner layer consisting mainly of cellulose and an outer layer of pectic substances, probably of a complex nature. Commercial agar is derived from the pectic layers of some species of Florideae such as Gelidium Amansii, G . cartilagineum (U. S. A.), G . japonicum, G . pacijicum, G . subcostatum, Acanthopeltis japonica, Ceramium Hypnaeoides, and Graeilaria conferuoides. Since Japanese agar has a world distribution, is often used as research material, and since chemical changes in the agar molecule may be introduced in its manufacture, this process as used in Japan will be briefly described. Japanese Method of Agar Manufacture.-After soaking and washing, the agar-bearing seaweeds or " agarophytes," mentioned above, are boiled with 25 times their weight of water for 2 hours, followed by the addition of 1 part of concentrated suIfuric acid per 500 parts of raw material and additional heating at about 80"for 14 hours. Approximately 3 hours before the solution is removed from the heating tank, 1 part of sodium hydrosulfite per 50 parts of agarophytes is introduced for bleaching. The pH of the solution is 5-6 just after the sulfuric acid is added and is 6-7 at the end of the heating. The liquid is filtered and the agar gel obtained on cooling is cut into suitable shape, frozen during the night and then thawed during the day, whereupon the water in the agar gel flows away, carrying with it water-soluble impurities. After sun drying, commercial agar results. 1. Composition Payen6 was the first to study the carbohydrate of agarophyte. He termed it gelose and assigned to it the formula CaHloOs. In 1884 Bauers found it to be a galactan. Neuberg and Ohle7discovered the presence of ester (ethereal) sulfate in commercial agar although prior to this Haas2 had proved its presence in carrageen mucilage or carrageenin. Recently, (4) E. Vasseur, Acta Chem. Scand., 2 , 900 (1948). (5) A. Payen, Compt. rend., 49, 521 (1859). (6) R. W. Bauer, J . prakt. Chem., [2] 30, 367 (1884). (7) C. Neuberg and H. Ohle, Biochem. Z.,126, 311 (1921).
318
T. MORI
Hands and Peat,* and Percival, Somerville and Forbesg isolated from methylated agar a compound which was found to be a derivative of 3,6-anhydro-~-galactose.The components of agar and their relative amounts will be described in some detail in the following sections. a. D-Galactose.--Yanagawa'O prepared crude agar from six species of agarophyte by extracting the raw materials with hot water, precipitating the agar with alcohol, and repeating the dissolution and precipitation twice. He found that this crude agar contained 65.2% of sugar as hexose. Galactose assays by the mucic acid method ranged from 37% in the agar from Gelidium subcostatum to 48% in that from Gracilaria conferuoides, while commercial agar gave a value of 41%. Araki'l prepared crude agar from Gelidium Amansii, the most important agarophyte, by the procedure of Yanagawa, except that he precipitated his product with acetone rather than with ethanol. The crude agar thus obtained, though contaminated with some nitrogenous compounds (N, 0.89 %), contained 67% of hexose assaying 32% galactose. Hayashi12found 30% of galactose in a more impure preparation from G. Arnansii. Percival and Somerville3isolated 65 % of a trimethyl-D-galactose (as its crystalline methyl glycoside anomeric mixture) from methylated commercial agar. From these results it may be concluded that D-galactose composes about two-thirds of the sugar content of agar. b. L-Galactose.-The presence of D,L-galactose in Porphyra laciniata, one of the most important seaweed foods of Japan, was reported by Oshima and Tollens13 as early as 1901. Piriel* isolated a crystalline derivative of D,L-galactose from commercial agar. L-Galactose was obtained by an enzymic procedure by Araki16from the agar of G. Amansii, G. subcostatum and Acanthopeltis japonica. According to Pirie,I4 agar contains 0.8% of L-galactose. (8) S. Hands and S. Peat, Nature, 142, 797 (1938); Chemistrg & Industry, 16, 937 (1938). (9) E. G . V. Percival, J. C . Sornerville and I. A. Forbes, Nature, 142, 797 (1938); E. G. V. Percival and I. A. Forbes, ibid., 1076 (1938); I. A. Forbes and E. G. V. Percival, J . Chem. SOC.,1844 (1939). (10) T. Yanagawa, Repts. Imp. Ind. Research Inst., Osaka, Japan, 14, No. 5, I (1933); Chem. Abstracts, 30, 3541 (1936). (11) C . Araki, J . Chem. SOC.Japan, 68, 1214 (1937); Chem. Abstracts, 32, 4172 (1938). (12) K. Hayashi, J . SOC.Trop. Agr. Taihoku Imp. Univ., 14, 5 (1942); Chem. Abstracts, 42, 5425 (1948). (13) K. Oshima and B. Tollens, Ber., 34, 1422 (1901). (14) N. W. Pirie, Biochem. J . , SO, 369 (1936). (15) C . Araki, J . Chem. SOC.Japan, 69, 424 (1938); Chem. Abstracts, 36, 7946 (1941).
SEAWEED POLYSACCHARIDES
319
c. 5,6-Anhgdro-~-galactose.-Takao~~ concluded that agarophyte contained fructose because it gave the Seliwanoff ketose reaction. On the other hand, Hands and Peatla and Percival, Somerville and for be^,^ obtained methyl 3,6-anhydro-2,4-dimethyl-P-~-galactoside (I) in crystalline form on further methylation of hydrolyzed methylated commercial
H
H I
agar. The melting point, single crystal x-ray diffraction photograph, and specific rotation demonstrated that I was enantiomorphous with the corresponding member of the D-series synthesized by Haworth, Jackson and Smith.'? This 3,g-aahydro derivative of galactose exhibits the Seliwanoff reaction with resorcinol and the Bredereck reaction with ammonium m ~ l y b d a t e . ~ The substances considered to be fructose by Takao and others may then well be 3,6-anhydro-~-galactose. Araki and from the Arai'* also isolated 3,6-anhydro-2,4-dimethyl-~-galactose methylated agar of Gelidium Amansii. Now the question arises whether 3,6-anhydro-~-galactosepre-exists in agar or is formed from an L-galactose sulfate component during methylation in the alkaline medium. Anhydro ring formation is known t o be a possibility in the alkaline hydrolysis of some sugar s u l f a t e ~ . 1 ~ -Jones ~~ and Peat23 consider it logical t o assume that during the methylation process the 3,G-anhydro ring appears in the L-galactose component on sulfate removal. This view is supported by the fact that Percival and c o w ~ r k e r s obtained * ~ ~ ~ ~ 3,6-anhydro-~-galactosefrom barium D-galactose sulfate in a manner analogous to its formation from the corresponding 6-p-toluenesulfonate. However, the washed agar employed in these experiments contained only a trace (0.1%) of sulfurgso that the amount (10-13 %) of 3,6-anhydro-2,4-dimethyl-~-galactose produced from meth(16) Y. Takao, Repts. Central Inst., Government of Formosa, 6, 13 (1918). (17) W. N. Haworth, J. Jackson and F. Smith, Nature, 142, 1075 (1938); J . Chem. Sac., 620 (1940). (18) C . Araki and B.Arai, J . Chem. Sac. Japan, 61, 503 (1940); Chem. Abstracts, 87, 89 (1943). (19) E . G . V. Percival and T. H. Soutar, J . Chem. Sac., 1475 (1940). (20) R. B. Duff and E. G. V. Percival, J . Chem. Sac., 830 (1941). (21) E. G. V. Percival, J . Chem. Sac., 119 (1945). (22) E. G. V. Percival, J. Chem. Sac., 1675 (1947). (23) W. G. M. Jones and S. Peat, J . Chem. Soc., 225 (1942).
320
T. MORI
ylated agar is not accounted for by such a desulfation process. Barry and DillonZ4prepared agar from bleached Gelidium latifolium by the same procedure as described previously for commercial agar except that the sodium hydrosulfite addition was omitted; the product contained 0.364 % S. PercivalZ6likewise prepared agar from Gracilaria confervoides and Gelidium crinale by a similar mild treatment and found 0.43% S and 0.47% S, respectively, in the products. Thus, none of these preparations would have contained sufficient sulfate residue, if it were all L-galactose 6-sulfate, to account for the amount of methy1 3,6-anhydro-2,4-dimethyl19-L-galactoside obtained. Barry, Dillon and McGettrick2Enoted that agar was essentially not attacked by periodic acid and that therefore no a-glycol groups were present in its structure. This demonstrates that 3,6-anhydro-~-galactose is a constituent of agar, since, if this unit were produced from L-galactose components in which C3 did not take part in a linkage, such L-galactose residues would present a-glycol units for periodate attack. ArakiZ7isolated a new disaccharide, agarobiose, from the agar of Gelidium Amansii. The agar was partially hydrolyzed with N sulfuric acid for one hour a t loo", neutralized, concentrated and precipitated by ethanol. The ethanol-soluble fraction was fermented with Saccharomyces sake and the non-fermented residue was isolated and crystallized from ethanol. The disaccharide, [(Y]D -5.8" in water, showed a strong Seliwanoff reaction and was sulfate-free. It was further characterized - 135.5' + - 111" in pyriby its phenylosazone (m. p. 218-219", dine-ethan~l~'~) and hexabenzoate (m. p. 142", [ a ] D -80.3' in chloroform). From methylated agarobiose Araki28isolated 3,6-anhydro-2,5-dimethylL-galactose dimethyl acetal (11). Since the disaccharide contained no
I1
sulfate group, this anhydro derivative could not have been formed by a (24) V. C . Barry and T. Dillon, Chemistry & Industry, 22, 167 (1944). (25) E. G. V. Percival, Nature, 164, 673 (1944). (26) V. C. Barry, T. Dillon and W. McGettrick, J . Chem. Soc., 183 (1942). (27) C. Araki, J . Chem. SOC.Japan, 66, 533 (1944); Chem. Abstracts, 42, 1210 (1948). (27a) C. Araki, private communication. (28) C. Araki, J . Chem. Soe. Japan, 66, 627 (1944); Chem. Abstracts, 42, 1210 (1948).
321
SEAWEED POLYSACCHARIDES
desulfation reaction. According t o E. E. P e r c i ~ a la, ~galactose ~ sulfate, pre-existent in agar, could not have produced a 3,6-anhydro ring on being subjected to the acid treatment employed by Araki in his isolation of agarobiose. In addition, Arakiao isolated 3,6-anhydro-~-galactose H
O
f
F
ActO
A c O C HP M e
E
H
H
H
I11
= H
Ha504 Ao,O
A
IV
OAc
c
O
C
P
H
H
H
OH
-
H
/
CHO
U
OAc
1
;c:$3-] OAc VII 1 . 0
CH~OAC AH co<~H
H
(OAc) OAc
A cHo < P 8 0 A c
H
OAc
IX dimethyl acetal from the methanolysis of agar. It can therefore be concluded that 3,6-anhydro-~-galactose is a true constituent of agar, albeit a small amount could indeed be formed by a desulfation process. E. Elizabeth Percival, Thesis, Edinburgh, 1942. (30) C. Araki, J . Chehem. Soc. Japan, 66, 725 (1944); Chem. Abslsacla, 41, 3496 (29) (1947).
322
T. M O M
PercivalO concluded that the amount of 3,6-anhydro-~-galactose isolable from agar was 10-13%. Employing a method that was hardly quantitative, ArakiSO obtained 18 % of 3,6-anhydro-~-galactose dimethyl acetal from Gelidium Amansii, 18% from Acanthopeltis japonica, 10% from Gelidium subcostatum, and 7 % from Ceramium Hypnaeoides. Pirie14 obtained heptaacetyl-D,L-galactose (IX) by the acetolysis of agar and proposed this as evidence for the presence of aldehydo-D,Lgalactose in agar. This conclusion is unwarranted in the light of the TABLEI Sulfur Contents of the Agar from Various Species of Agarophytes Agarephyte Gelidium latifolium Gracilaria confervoides Gelidium crinale Gelidium Amansii Acanthopeltis japonica Gelidiurn subcostaturn Ceramium Hypnaeoides Acanthopeltis japonica Gelidium Amansii Gelidium japonicum Gelidium subcostaturn Ceramium Hypnaeoides Cracilaria confervoides Commercial agar
s, %
Investigator
0.36
Barry and Dillon''
O 43} 0.47
Percivalst
1.20 0.62 0.78 1.06
1.14
Yanagawa10
2.22
3.76 0.77
results of Freudenberg and Soff ,*I who obtained heptaacetyl-D-glucose by a similar treatment of derivatives of D-glucopyranose. Jones and Peatz3considered that both D- and L-galactose were components of agar and that on acetolysis they were liberated and appeared in part, as the rather readily crystallizable heptaacetyl-D,L-galactose. Cottrell and Percival,ga however, demonstrated that heptaacetyl-D,L-galactose (IX) was an acetolysis product of methyl 3,6-anhydro-~-~-galactopyranoside (111). They have accordingly suggested that I11 is acetylated t o IV which undergoes acetolysis to V. The 3,g-anhydro ring may then be cleaved alternatively to the transient intermediates V I or VII which yield heptaacetyl-L-galactose and heptaacetyl-D-galactose, respectively, on further acetylation. Cottrell and Percival therefore considered that (31) K. Freudenberg and K. Soff,Ber., 70, 264 (1937). (32) T.L. Cottrell and E. G. V. Percival, J . Chem. Soc., 749 (1942). (33) C. Araki, Collected Papers for the Celebration of the Forty-fifth Anniversary of the Founding of Kyoto Technical College, 69 (1948).
SEAWEED POLYSACCHARIDES
323
in the acetolysis of agar the heptaacetyl-D,L-galactose is derived exclusively from a preformed 3,6-anhydro-~-galactoseentity. This is supported by the fact that the yield of heptaacetyl-D,L-galactose (l0-200/,) agrees with the estimate of the 3,6-anhydro-~-galactosecontent of agar and also by the fact that PirieI4 was unable to obtain heptaacetyl-D,Lgalactose from D-galactose on application of the same procedure. d . Ester Sulfate.-As stated previously, ester (ethereal) sulfate was first found in agar by Neuberg and Ohle.? The sulfur contents found in the agar from different species are shown in Table I. Although the values of the Japanese workers are too high because of the incomplete removal of sulfate-containing ash, it will be seen from Table I that the sulfur content varies with the species of agarophyte. It is very much less than that of carrageenin. e. Other Components.-It has been reported that agar contains 1.8-5.7% of p e n t o ~ e , ~ ~1.0-3.6% -~? of methylpento~e,~~.1~,~~J~ and 3.6-7.4% of uronic a ~ i d . ~ It~ is . ~not~ certain , ~ ~ whether these are true components of the agar molecule. 2. Structure
As in the case of other polysaccharides, the methylation method was applied to agar to clarify its structure. Percival and Somerville3 succeeded in obtaining methylated agar by the acetylation of commercial CH,OMe
k
I
x
OMe
agar with acetic anhydride and pyridine, followed by simultaneous deacetylation and methylation with dimethyl sulfate and sodium hydroxide. Hands and Peat8 later found that agar could be methylated directly with dimethyl sulfate and alkali. Percival and Somerville3 hydrolyzed methylated agar with dilute acid and obtained 2,4,6-trimethyl-a-~galactose (X) as the main product (65%). The constitution of X was established as follows. (1) I t was converted to 2,3,4,6-tetramethyl-~(34) 13. Matsui, J . Coll. Agr. Imp. Univ. Tokyo, 6,413 (1916); Chem. Abstracts, 11, 2920 (1917). (35) C. R. Fellers, Znd. Eng. Chem., 8, 1128 (1916). (36) T. Yanagawa and Y. Nishida, Repts. Imp. Znd. Research Znst., Osaka, Japan, 11, No. 14 (1930); Chem. Abstracts, 20, 1642 (1931). (37) M . Furuichi, Repts. Tolfori Higher Ayr. School, Japan, 1, 31 (1927).
324
T. MORI
galactose, which excluded the possibility of substitution at position C5 and established the trimethylgalactose as belonging to the D-series. (2) It formed a dimethylgalactosazone, proving the presence of a methoxyl group on C2 of the trimethylgalactose. (3) The trimethylgalactonic acid, obtained by oxidation with hypobromite, formed only a trimethylgalactono-b-lactone, showing that C4 was occupied by a methoxyl group. Thus, it became clear that two of the three methoxyl groups were located on C2 and C4, and that C5 was not methylated. (4) Then, only two structures for the trimethylgalactose were possible, namely, 2,3,4- and 2,4,6-trimethyl-~-galactose. The trimethylgalactose in question had properties different from those of the former, which was knownla8and it could be converted to dimethylmucic acid by oxidation with nitric Therefore the trimethylgalactose is 2,4,6-trimethyl-~-galactose, an assignment which has been definitely confirmed by synthesis. 40 The yield of 2,4,6-trimethyl-~-galactose from methylated agar was improved by Hands and Peat* by the employment of methanolysis. ArakP9 isolated 2,4,6-trimethyl-~-galactose on hydrolysis of the methylated agar of Gelidium Amansii. It was therefore shown that in agar D-galactopyranose units are linked through the 1 + 3 positions and this was the first known case of the existence of the 1+ 3 linkage in a galactan. Hands and Peat,s and Percival, Somerville and Forbes19 isolated 3,6-anhydr0-2~4-dimet hyl-L-galact ose on further met h ylat ion of the methylated agar hydrolyzate but not from the original hydrolyzate. On the other hand, Araki41 obtained 3,6-anhydro-2-methyl-~-galactose dimethyl acetal (XI, b. p. 131-132" at 0.05 mm., nD 1.4647, [a]D -33.4" in chloroform) by methanolysis of the methylated agar of Gelidium Amansii. Compound X I underwent osazone formation with demethylation, to yield 3,6-anhydro-~-galactosephenylosazone of m. p. 215"; the enantiomorph, m. p. 215", had been synthesized by Ohle and Thiel.42 Therefore the methoxyl group in X I is on C2. The acetal group in X I was removed by hydrolysis and the product was oxidized with hypoacid (m. p. 142O, bromite to yield 3,6-anhydro-monomethyl-~-galactonic DI.[ -70.0" in water), which consumed one mole of oxidant on oxidation with periodic acid. Positions 2, 4, and 5 come into question for a monomethyl ether of 3,6-anhydro-~-galactonic acid. Of these, only the %sub(38) s. W. Challinor, W. N. Haworth and E. L. Hirst, J . Chem. Soc., 258 (1931);M. Onuki, J . Agr. Chem. SOC.Japan, 9, 214 (1933);Bull. Inst. Phys.-Chem. Research (Tokyo), 12, 614 (1933). (39) C. Araki, J . Chem. Soc. Japan, 68, 1362 (1937);Chem. Abstracts, 32, 4172 (1938). (40)D.J. Bell and S. Williamson, J . Chem. Soc., 1196 (1938). (41) C.Araki, J . Chem. Soc. Japan, 61,775 (1940);Chem. Abstracts, 37,90 (1943). (42) H.Ohle and H. Thiel, Ber., 66,525 (1933).
SEAWEED POLYSACCHARIDES
325
stituted acid would consume periodate, thus providing further support for the assignment of the methoxyl group in XI to C2. Rao and Smith43 synthesized crystalline methyl 3,6-anhydro-cu-~-galactopyranosidebut unfortunately this, in its derivatives described by them, cannot be compared with the derivatives of Araki since none were in common. Assum-
XI ing a pyranoside structure in the agar constituent, the isolation of 3,tjanhydro-2-methyl-~-galactosefrom methylated agar shows that the anhydro-L-galactose residue is joined to the other components of agar through its positions one and four. Jones and Peat2a separated methylated agar into an acidic and a neutral fraction by precipitation methods. From the hydrolyzate of the acidic fraction they isolated 2,4,6-trimethyl-~-galacto .el 2,3,4,6-tetraacid (XII, methyl-D-galactose, and 3,6-anhydr0-2,5-dimethyl-~-galactonic as the crystalline amide of m. p. 173"). The structure assignment of XI1 was made on the following basis. The rotation of its amide, [a]D -75.7" H
XI1
in water, was of the same order and sign as that of 3,6-anhydro-2,4dimethyl-L-galactonamide, [.ID -74' in water. There are three possible dispositions for the two methoxyl groups: 2,4;2,5; and 4,5. The amide in question exhibited a negative Weerman test for a-hydroxy acids; consequently the 4,5-dimethyl compound is excluded. The isolated amide showed a melting point some 20' higher than that reporteds." for the known 3,6-anhydro-2,4-dimethyl-~-galactonamide (m. p. 151') and it is not probable that the two are identical. Therefore the acid isolated from the acid portion of the methylated agar is 3,6-anhydro-2,5-dimethylGgalactonic acid (XII). On acetolysis of methylated agar with subsequent oxidation, (43) (Mrs.) P. A. Rao and F. Smith, J . Chem. SOC.,229 (1944).
326
T. MORI
Percival and Th0mson4~obtained a mixture of disaccharide esters from which, on hydrolysis and derivatization, they isolated 2,3,4,6-tetramethylD-galactose anilide and a mixture of methylated acids. From these acids they obtained 3,6-anhydro-2,5-dimethyl-~-galactonic acid, the structure of which was determined by almost the same means as those employed by Jones and Peat.2a On methanolysis of hexamethylagarobiose, Araki28 isolated 3,6-anhydro-2,5-dimethyl-~-galactose dimethyl acetal (XIII),
XI11 the structure being decided independently, because of war conditions, in a manner similar to that of Jones and Peat.23 acid by From the isolation of 3,6-anhydro-2,5-dimethyl-~-galactonic Jones and Peat,23and by Percival and T h o m s ~ ntogether ,~~ with the isolation of 3,6-anhydro-2,5-dimethyl-~-galactose dimethyl acetal by Araki,28 it follows that the 3,6-anhydro-~-galactose entity in agar is joined to neighboring sugar residues through its positions C1 and C4. As to the nature of the neighboring sugar units, Araki46carried out the following experiments. From the higher-boiling fraction (b. p. 162-166" at 0.49 mm.) of a partial methanolyzate of methylated agar, he obtained a crystalline methyl pentamethylglycoside of a disaccharide (m. p. 99-loo", [a]+48" in water), which on further methanolysis gave methyl 2,3,4,6-tetramethyl-~-galactoside and methyl 3,6-anhydro-2-methyl-~galactoside,41 indicating that the disaccharide was 3- or 4-~-galactopyranosyl-3,6-anhydro-~-galactose.In another experiment, Araki28 obtained hexamethylagarobiose dimethyl acetal (b. p. 155-160" a t 0.052 mm., [a], -11.1' in water), from which 2,3,4,6-tetramethyl-~were separated on galactose and 3,6-anhydro-2,5-dimethyl-~-galactose hydrolysis. Thus it was established that agarobiose was 4-~-galactopyranosyl-3,6-anhydro-~-galactose (XIV) and that therefore the 3,6anhydro-L-galactose entity of agar is joined by its C4 to the C1 of a D-galactose unit. In addition, it was demonstrated by Percival and coworker^^^^^ that no tetramethylgalactose was detectable in the hydrolyzate of methylated agar. (44) E. G. V. Percival and T. G. H. Thomson, J . Chem. Soc., 750 (1942). C.Araki, J . Chem. SOC.Japan,62,733 (1941); Chem. Abstracts, S7,91 (1943).
(46)
327
SEAWEED POLYSACCHARIDES
As to the whole molecule of agar, Jones and Peatz3proposed that it is a linear polysaccharide, esterified with sulfuric acid, the unit chain of which consists of approximately nine D-galactopyranose residues combined by 1 + 3 glycosidic unions. This unit chain or repeating unit is terminated
H
OH XIV
at the reducing end by an L-galactose residue which is united with the remainder of the chain by a glycosidic linkage engaging not C3 but C4, in this case. Furthermore, position C6 of each L-galactose unit is esterified with sulfuric acid. Such a repeating unit is shown in XV. The reducing group of the L-galactose residue, (a), in each repeating unit, is H
.
H
XVI
attached to a second unit chain through the non-reducing D-galactose residue, (b), of the second repeating unit. When the sulfate group at C6 is removed by alkaline hydrolysis, as in alkaline methylation, a 3,6anhydro ring is developed*O in the L-galactose residue and (a) in XV would change to a 3,6-anhydro-~-galactoseresidue (XVI). Jones and Peatz3have made the interesting suggestion that D-galactose 1-sulfate substituted at C3 could be converted by simple intramolecular oxidationreduction to L-galactose 6-sulfate substituted at C4, as in (a) of XV. The above conception of the structure of the agar molecule explains
328
T. MORI
the isolation from hydrolyzed methylated agar : of 2,4,6-trimethyl-~galactose as a major product; of 3,6-anhydro-2-methyl- (or 2,4-dimethylon further methylation of the hydro1yzate)-L-galactose as a lesser product, with absence of detectable amounts of 2,3,4,6-tetramethylgalactose;of 3,6-anhydro-2,5-dimethyl-~-galactonicacid from the hydrolyzate of methylated oxidized agar; and of L-galactose on acid hydrolysis of agar. On the other hand, as detailed previously, the sulfur content of agar is too low to allow for the presence of L-galactose sulfate residues as suggested in the model of Jones and Peat.23 Furthermore, the methoxyl content for the methylated polysaccharide should be 42% whereas the highest recorded value is 35%.23 In spite of proof for the pre-existence of 3,6-anhydro-~-galactose in the molecule, in addition to L-galactose sulfate, the former is not included in the proposed structure. Positive evidence is lacking for the position of the sulfate group attached to the L-galactose entity. Although the anomeric nature of the glycosidic unions is not certain, it is probable that agar is composed predominantly of 8-D-galactose residues because the rotations of acetylated and methylated agar are strongly negative. Much further work, including molecular weight determinations and the isolation of galactose sulfate, will be required before the structure of the agar molecule can be established with certainty.
111. MUCILAGE OF Dilsea Edulis Dilsea edulis belongs to the family Dumontiaceae, order Cryptonemiales, subclass Florideae. While it differs from carrageen not only taxonomically but also in the composition and properties of its mucilage, the uses of the two are nearly identical. This mucilage has been studied by Dillon and coworkers,40~41It is prepared by extracting the raw material with dilute hydrochloric acid and precipitating with alcohol. It forms a highly viscous solution that does not set to a gel, thus differing from carrageenin. 1. Composition The mucilage consists mainly of D-galactose, the content of which is about 70% on an ash-free basis. L-Galactose is considered to be absent because the benzimidazole procedure of Link and failed to detect it. While carrageenin is believed to contain no uronic acid, Dilsea mucilage contains 9.6-11.0% of it. The nature of the uronic acid is (46) V. C. Barry and T. Dillon, PTOC. Roy. Irish Acad., SOB,349 (1945). Roy. Irish Acad., 63B, 45 (1950). (47) T.Dillon and J. McKenna, PTOC. (48) S. Moore and K. P. Link, J . Biol. Chem., 133, 293 (1940);R.Lohmar, R.J. Dimler, 5. Moore and K. P. Link, ibid., 143, 551 (1942);R. J. Dimler and K. P. Link, ibid., 160, 345 (1943).
S E A W E E D POLYS-4CCHARIDES
329
undetermined but it is believed to be an integral part of the molecule since the content of uronic acid is not changed significantly by any process of purification nor by conversion to a degraded and desulfated product to be described later. The mucilage does not exhibit the Seliwanoff reaction, as does carrageenin. Ester sulfate is present to the extent of 10.2% (as SO,), a value considerably less than that of carrageenin. From these results and the elementary analyses, Dillon and McKenna47 have assigned to the mucilage the formula (CeHioOs)9 (CeHeOs) (f%) 2. 2. Structure Employing a modification of the method of B ~ r n e t tthe , ~ ~mucilage was acetylated at 75" with acetic anhydride in the presence of chlorine was completely and sulfur dioxide. The triacetate so 0btained~~8~O desulfated and was a mixture of products with differing degrees of degradation. The polysaccharide regenerated from the acetate was found by analysis to correspond to the formula (C6H~~O~)~(C6H806). The sulfur-free triacetyl derivative was simultaneously deacetylated and methylated to yield a product containing 41.5% of methoxyl. Methanolysis of the methylated product by Dillon and M ~ K e n n a ~ ~ some dimethylgalactose, a yielded some 2,3,4,6-tetramethyl-~-galactose, high yield of 2,4,6-trimethyl-~-galactose (X), and a trace of 2,3,6trimethyl-D-galactose (XVII). No 2,3,4-trimethyl-~-galactose was detected in the hydrolyzate, thus indicating the absence of a 1 + 6 linkage in the molecule. The 2,3,6-trimethyl-~-galactose has been established6I from other sources and was herein characterized by the CH,OMe
H
OMe
XVII
trimethyl-y-lactone obtained on oxidation. 2,4,6-Trimethyl-~-galactose was identified by its melting point and by that of its anilide. Barry and Dillon4* isolated glyoxal as its osazone from the periodate-oxidized mucilage, indicative of an a-glycol group in the molecule. From the hydrolytic products of the methylated mucilage and (49) W. L. Barnett, J . SOC.Chem. Id., 40, 8~ (1921). (50) T.Dillon and P. O'Colla, Nature, 146, 749 (1940). (51) R. E. Gill, E. L. Hirst and J. K. N. Jones, J . Chem. Soc., 1025 (1946); E. L. Hi&, J. K. N. Jones and (Mrs.) W. 0. Walder, ibid., 1225 (1947); J. I. Cunneen and F. Smith, ibid., 1141 (1948).
330
T. MORI
the periodate oxidation results, it is inferred that Dilsea mucilage is built up of D-galactose residues mutually combined mainly by 1 -+ 3 linkages together with a few 1+ 4 bonds but no 1--+ 6. The isolation of dimethylgalactose would indicate that, unless demethylation had occurred during the hydrolysis, some branched chains were present. The position of the sulfate residue is undefined although Barry and Dil10n~~ suggested that it was located on C4 because of its alkali stability. Furthermore, the mode of union of the uronic acid component is entirely unknown. Thus it is difficult to depict even a rough picture of the molecule of this mucilage. IV. CARRAGEENIN The mucilage of carrageen or Irish moss was first studied by Schmidt62 and was given the name carrageenin by Stanford.6s Fluckiger and ObermaieP4 claimed to have proved the presence of galactose in carrageenin and subsequently Hadecke, Bauer and Tollenss6 reported the occurrence of fructose in addition. Then S e b o P found small quantities of pentose and glucose. Muther and Tollens6’ confirmed the presence of glucose but Haas and Russell-WelkP found it only in a hot-water extract of carrageen. As already noted, Haas2 recognized that the polysaccharide was a sulfate ester. Although the term carrageen, and accordingly carrageenin, seems to be confined to the red alga Chondrus crispus and its mucilage, the mucilages of the closely related seaweeds Chrondrus ocellatus, Iridaea laminarioides or more correctly Iridophycus faccidum, and Gigartina stellata are discussed in this section because they closely resemble carrageenin and each other in properties and chemical structure. MariniBettblo and Ib4iieP have studied the mucilages of Chondrus canaliculatus and of Gigartina chamissoi; their results, unfortunately, are not available to the author in detail. 1. Cold-water Extract and Hot-water Extract
Haas2 prepared a cold-water extract by extracting C . crispus with cold water for about one hour and then evaporating the filtered solution (52) C. Schmidt, Ann., 61, 29 (1844). (53) E. C. C. Stanford, J. SOC.Arts, 10, 185 (1862). (54) F. A. Fliickiger and L. Obermaier, Neues Repertorium Pharm., 380 (1868). (55) J. Hadecke, R. W. Bauer and B. Tollens, Ann., 288, 302 (1887). (56) J. Sebor, Oesterr. Chem. Ztg., 3, 441 (1900); Chem. Zentr., 71,II, 846 (1900). (57) A. Miither and B. Tollens, Ber., 87, 298 (1904). (58) P. Haaa and Barbara Russell-Wells, Biochem. J., 23, 425 (1929). (59) G. B. Marini-Bettdlo and J. IbBflez, Ann. chim. applicata, 38, 383 (1948); Chem. Abstracts, 43, 4728 (1949).
33 1
SEAWEED POLYSACCHARIDES
to dryness on a water-bath. The residual seaweed was washed continuously for three days in running water, to remove essentially all of the material so soluble, and was subsequently heated with water over a water-bath, the resulting solution yielding the so-called hot extract on filtration and evaporation. The cold extract is 47% of the dry weight of the plant while the hot extract constitutes 23%, a ratio of 2: 1. Thus 70% of the weed can actually be brought into water solution. Mori and Tsuchiyaaoprepared similar cold and hot aqueous extracts from C. ocellatus except that these extracts were subjected to dialysis with subsequent concentration and precipitation by ethanol; the dry weight yields were 21 % (cold extract) and 7% (hot extract) although considerable mechanical loss occurred with the latter on hand separation of the cortical layer. Similar studies have not been reported on I . laminarioides and G . stellata. a. Physical Properties.-The significant difference in the two extracts is that the hot-water extract sets to a gel but the cold-water extract does not, the main reason for this apparently being the difference in the ash constituents (especially calcium) mentioned later. The specific rotation of the carrageen cold-water extracted material is +50° while that of the hot extract is +ao.The cold extract from C. ocellatus also does not gel while the hot extract does, although the gel is not as firm as that from carrageen. The reason for this probably lies in the greater amount of calcium in the latter (Table 11). TABLE I1 Asha Constituents of Hot- and Cold-water Extracts from Chondrus
Si, Seaweed
C . crispusB2 C. ocellatu,ssQ 0
Extract
%
Cold Hot Cold Hot
0 0.8
Ca, %
Mg,
K,
%
%
5.5 29.9 11. 8 18. 2
-
24.5 2.5 5.1 2.1
4.8 7.4
Na, %
SO,, %
PO, %
13.7 1.0
63.8 66.6 51.8 55.6
-
14.4
7.7
6.6 1.4
Ash as sulfate.
Viscosity and fractionation studies,Boa~Bob as well as electrophoretic and ultracentrifugal measurementsBoa indicate that carrageenin is polydisperse but no separable components were obtained. (60) T. Mori and Y. Tsuchiya, J . Agr. Chem. SOC.Japan, 16, 1065 (1939); Chem. Abstracts, 34, 3313 (1940). (60a) R. C. Rose and W. H. Cook, Can. J. Research, F27, 323 (1949). (60b) R. C. Rose, Can. J. Research, F28, 202 (1950). (60c) W. H. Cook, R. C. Rose and J. It. Colvin, Biochim. el Biophys. Acta, 8, 595 (1952).
332
T. MORI
b. Compot?itwn.-Russell-WellsB1found 33.7% of galactose in carrageen cold-water extract and 29.5 % in the hot-water extract, but the figures found by Percival and coworkers8zare reversed. The galactose contents of the two extracts from C . ocellatus have been estimated by Mori and TsuchiyaBo(Table 111); they are somewhat higher than those from carrageen. The carrageen cold extract contains higher quantities of apparent ketose than does the hot extract from the same source; the reverse occurs with C.ocellatus (Table 111). TABLEI11 Analyses of Hot- and Cold-water Extracts from Chondrus Seaweed
c. criapus6' C. ocellutus~@ a
Extract
Cold Hot Cold Hot
Total N, Galactose, Ketose, % % %
-
34 36.9
0.65 0.61
43.6 40.2
Sulfur (SO,), Ash. % %
20-22" 17" 8.4 12.3
Based on the sirup obtained from the hydrolyzate after galaotose removal.
35.1
-
31.1 24.9 3
22.4' 18.7' 18.5 17.6
As sulfate.
Glucose has been found in the carrageen hot-water extract and only in small amount.6B-s8 The pentose content in carrageen was estimated as 1-1.4% (cold methylpentose ww found only extract)68*62 and 1-1.9% (hot extract)68*82; in the hot extractsa and to the extent of about haIf that of the pentose content. It is difficult to draw definite conclusions from the above results since the ratios of the cold and hot extract contents are reversed by different investigators. It may be concluded, however, that there is no significant difference between the two extracts from carrageen as regards organic components since the structures of the polysaccharides from the two sources are the same.sz The ash constituents of the hot and cold extracts from C. mispusa2 and C.ocel2atusB0are shown in Table 11. From the table it will be noted that with carrageen the ash of the cold extract consists mainly of potassium and sodium whereas that of the hot extract is composed chiefly of calcium. In the two extracts from C . ocellatus there is not so great a divergence in these respects. It is believed that some requisite amount of the bivalent calcium ion is required for gel formation. (01) Barbara Russell-Wells, Biochem. J . , 16,578 (1922). (62) J. Buohanan, E. Elizabeth Percival and E. G. V. Percival, J . Chem. Soc., 51 (1948).
SEAWEED POLYSACCHARIDES
333
2. Composition
a. D-GaZactose.-Galactose has long been known to be the main component of carrageenin, where it occurs in the D-configuration together with a very small amount of the L-form. The galactose contents in the hot- and cold-water extracts of C. crispus and C. ocellatus have been discussed in the preceding section. Mori and T ~ u c h i y aand , ~ ~M ~ r i found ,~~ 42% of galactose in the barium salt of the mucilage of C . ocellatus and of I . laminarioides, preparede6 as follows. The seaweed was extracted with cold water, the extract was dialyzed, and the vacuum-concentrated solution was heated a t 120" for 1.5-3 hours (no reducing power produced), filtered and again concentrated. The barium salt of the mucilage was precipitated by the addition of barium chloride and methanol. The product was dissolved in water and again precipitated with methanol in the presence of barium chloride. This process was repeated several times and finally several times without the barium chloride addition, until the salt was pure and showed a 1 :1 ratio of sugar residue to combined sulfate. Another method differed in that the complex with basic lead acetate was precipitated and decomposed with hydrogen sulfide in the presence of barium carbonate. According to Dewar and PercivallBB the galactose content of G. stellata was 40%. It can be concluded that the mucilage contains about 3 5 4 0 % of galactose whereas the calculated amount in the barium salt, [(CeHsOsS)zBa],, should be 58% if galactose were the only organic component. 6. L-Galactose.-Araki and Arsie7 isolated L-galactose in small quantity from the mucilage of C. ocellatus. Johnston and Percivale8obtained 2,3,4,6-tetramethyl-~-galactoseand 2,4,6-trimethyl-~-galactose from the hydrolytically resistant fragment of carrageenin but did not record their amounts. c. "Ketose."-Fluckiger and Obermaier,54and subsequently S e b ~ r , ~ ~ reported the presence of ketose. Mori and Tsuchiyae3inferred that the ketose might be D-fructose because the hydrolyzate of C. ocellatus mucilage contained no n-glucose and very little, if any, D-mannose, but was (63) T. Mori and Y. Tsuchiya, J . Agr. Chem. SOC.Japan, 14, 616 (1938); Chem. Abstracts, 32, 9176 (1938). (64) T. Mori, J . Agr. Chem. SOC.Japan, 19,297 (1943); Chem. Abstracts, 44, 7783 (1950). (65) T. Mori and Y. Tsuchiya, J . Agr. Chem. SOC.Japan, 14, 609 (1938); Chem. Abstracts, 32, 9175 (1938). (66) E. T. Dewsr and E. G. V. Percival, J . Chem. Soc., 1622 (1947). (67) C. Araki and K. Arai, Collected Papers for the Celebration of the Forty-fifth Anniversary of the Founding of Kyoto Technical College, 80 (1948). (68) R. Johnston and E. G. V. Percival, J . Chem. SOC.,1994 (1950).
334
T. MORI
still fermentable by a yeast that did not ferment D-galactose. The amounts of apparent ketose are shown in Table 111. Percival and coworkerss2 stated that, by colorimetric estimation, ketose might be present to the extent of 20-22% and 17%, respectively, in the D-galactosefree sirups from the hydrolyzed cold and hot water extracted material of carrageen. Young and Rices9 recorded 14% and 21% of ketose t o be present in carrageenin. Ketose was detected, but was not estimated, in the hydrolyzate of the hot-water extracted material from G. stellata.66 However, no definite derivative of a ketose has been isolated from any of these mucilages. M o r P considered a ketose to be an integral part of the mucilages of C. ocellatus and I. laminarioides, since its amount was essentially unchanged by various methods of purification. On the other hand, Hassid7I recorded the absence of ketose in a purified preparation from I . laminarioides. d. D-Glucose.-The existence of glucose in carrageen has long been k n 0 w n ~ ~but ~ ~Haas 7 and Russell-WellsS8found it only in the hot-water extract. Their view has been confirmed by Percival and coworkerss2 who isolated crystalline methyl tetraacetyl-0-D-glucopyranoside and 2,3,4,6-tetramethyl-~-glucosefrom the material extracted by hot water but not from that extracted by cold water. After destroying any possible fructose, Mori and Tsuchiyas3could not obtain glucosazone or potassium acid saccharate from the hydrolyzate of the mixed hot and cold water extract material from C. ocellatus and considered that no significant amount of glucose was present. Recently, Dillon and O ’ C ~ l l ahave ~~ stated that the hot-water extract material from carrageen gave a purple color with iodine, showing the presence of Floridean starch, and that glucose was detectable only in the hot-water extract because the starch was not extractable by cold water. Consequently, in these types of mucilages, glucose should be regarded as a contaminant, e. 2-Keto-~-gluconic Acid.-Young and Ricesg have reported the isolation of an interesting compound, 2-keto-~-gluconicacid (XVIII), from carrageenin after hydrolysis in an inert atmosphere. Dewar and Percivallse however, were unsuccessful in isolating it from carrageenin or from the mucilage of G . stellata. Should the presence of this substance be verified, it could be considered as being responsible, at least in part, for the ketose reactions exhibited by these materials. f. Pentose and Methy1pentose.-The content of pentose was found to be 2.5% by Sebor,660.9% by TakaoI6 and 1.4-1.9% by Russell-Wells.61 (69) (70) (71) (72)
E. G . Young and F. A. H. Rice, J . Biol. Chern., 164, 35 (1946). T. Mori, unpublished work. W. Z. Hassid, J . Am. Chem. Soc., 66, 4163 (1933). T. Dillon and P. O’CoUa,Proc. Roy. Zrish Acad., 64B,51 (1951).
SEAWEED POLYSACCHARIDES
335
On the other hand, Morie4could not obtain any precipitate of the 2-furaldehyde-barbituric acid complex, characteristic of pentose, from 5 g. of the purified barium salt of the mucilage, whereas he obtained it from an unpurified specimen. From this he concluded that pentose should be recognized as an impurity in the mucilage. Johnston and Percivales identified 2,3,4-trimethyl-~-xylose in the hydrolyzed products of carrageenin but they have stated that it may have been derived from a contaminating xylan. These views find support in that pentose was not COOH
I co
I
H°FH HCOH I
HCOH
I
CHZOH XVIII
detected in the hot-water extract from G . stellatass and that xylan was found to be present in red algae, Rhodymenia palmata, by Percival and Chanda,73and by Dillon and Methylpentose was detected by a color reaction in a crude mucilage but not in a purified specimene3and was thus recognized as a contaminant, a fact supported by the negative methylpentose reaction exhibited by the hot-water extract of G . sbellata. g. Summary of Carbohydrate Constituents.-Mannose, uronic acid, acetyl and methoxyl were all absent in the extract from C. ocellatus.68 From all the above it may be deduced that the mucilage polysaccharide of carrageen consists of D-galactose, L-galactose, a ketose or, possibly, 2-keto-D-gluconicacid (XVIII), whereas the glucose, pentose and methylpentose detected by various workers are contaminants. This, however, does not mean the exclusion of a currently unknown constituent of the polysaccharide. h. Ester Sulfate.-Since Haas2 first demonstrated the presence of combined sulfate in carrageenin, it has been established that it occurs widely in the seaweed mucilages. Mori and Tsuchiyae3found that all of the sulfur in the mucilage was present as sulfate. The amount of sulfate residue is generally about 28% (as SO,) in the crude barium salt of the mucilage polysaccharides from C . ocellatus and I . laminarioides and 3 1% in a specimen purified by fractional p r e c i p i t a t i ~ nthe ~ ~calculated ~~~; value (73) E. G. V. Percival and S. K. Chanda, Nature, 166, 787 (1950). (74) V. C. Barry, T. Dillon, B. Hawkins and P. O’Colla, Nature, 166, 788 (1950).
336
T. MORI
for a barium hexose monosulfate residue is 31.07%. From this it was concluded that the molar ratio of sulfate t o hexose residue was 1:l. Dewar and Percivaleafound only 24% of sulfate in the hot-water extract from carrageen and from G . stellata; here the sulfate content was less. Since more than one-half of the total mucilage sulfur was lost on ashing, Russell-Wellsa1suggested that some content of ammonium salt might occur, while Yanagawa'" suggested the presence of a diester, ROS020R', and Butler,76as well as Mori and Tsuchiya,6Sinferred the occurrence of an acid salt. Haas' view is contradicted by the finding that nitrogen-free mucilage still lost more than one-half of its sulfur content on a ~ h i n g . The ~ ~ diester is excluded by the fact that the barium content in the purified salts from C. ocellatusa3and from I . l a r n i n a r i o i d e ~muci~~ lages agrees well with the formula (ROS020)2Ba. For these reasons it is very probable that the polysaccharide occurs in the seaweed mainly as a neutral salt but with some content of acid salt, as proposed by Butler76 and by Mori and T s u ~ h i y a . ~ ~ 3. Structure
For structure elucidation, it is desirable to methylate the polysaccharide in its original and in its desulfated form. In this case the sulfate group was alkali-resistant . Haas and Russell-WellsS8showed that sulfate hydrolysis, in 3% sodium hydroxide for 16.5 hours at l l O o , proceeded to the extent of only 20%, a fact confirmed by Percival and coworkers.E2 Mori and T s u ~ h i y a , ?and ~ M ~ r i also , ~ ~experienced difficulty in the alkaline desulfation of the mucilages from C. ocellatus and I . laminarioides. Dillon and O ' C ~ l l a obtained ~ ~ , ~ ~ sulfur-free, acetylated and heterogeneously degraded carrageenin by acetylation with acetic anhydride and sulfuryl chloride. Without knowledge of the work of Dillon and O'Colla,60 Mori and T s u ~ h i y aunexpectedly ~~ obtained a somewhat degraded but desulfated triacetate,DI.[ $65" in chloroform, on treating the mucilage from C . ocellatus with acetyl chloride and pyridine according to the method applied to inulin by Haworth and Streight.77 Deacetylation yielded a substance giving a strong Seliwanoff ketose reaction and having a mean molecular weight of 5050 as assayed by the chemical endgroup method of Bergmann and Machemer.?* The acetylated, degraded polyaaccharide of C. ocellatus thus obtained was deacetylated and methylated by dimethyl sulfate and alkali and then by Purdie's reagents (silver oxide and methyl iodide). Methanolysis of (75) Margaret R. Butler, Biochem. J . , 28, 759 (1934). (76) T. Mori and T. Tsuchiya, J . Agr. Chem. SOC.Japan, 14, 585 (1941). (77) W. N. Haworth and H. R. L. Streight, Helv. Chim. A d a , 16, 609 (1932). (78) M. Bergmann and H. Machemer, Ber., 63,316 (1930).
SEAWEED POLYSACCHARIDES
337
the methyl ether gave mainly methyl 2,4,6-trimethyl-~-galactoside (methyl glycoside of X), the structure of which was determined76in a manner similar to that of Percival and S~merville,~ thus proving that D-galactose residues are joined 1--+ 3. The positive rotations exhibited by the polysaccharide and its derivatives make it probable that the preponderantly n-galactose residues are joined by a - ~ - l i n k a g e s . ~ ~ In a manner similar to the above, Moris4 obtained the methylated, desulfated mucilage of I . laminarioides and this on methanolysis again yielded methyl 2,4,6-trimethyl-~-galactosideas the main product. From this it must be concluded that the major portion of the polysaccharide is composed of D-galactopyranose units linked 1 -+ 3 as with agar and with Chondrus mucilage. On the other hand, H a s ~ i d reported ~ ' ~ ~ ~the mode of linkage as 1 --+ 4 in the mucilage from the American I . laminarioides. It is not clear whether the discrepancies in the work of Hassid and of Mori are due to seaweed species differences or to other reasons. In the case of carrageenin, Johnston and Percivals8 prepared a dialyzable, degraded polysaccharide from which 25 % of the original sulfate group had been removed. After methylation followed by methanolysis, the degraded polysaccharide gave 2,4,6-trimethyl-~galactose accompanied by some 2,3,4,6-tetramethyl- and 2,6-dimethyl-~galactose, thus demonstrating that t8heprincipal linkage in carrageenin is 1 -+ 3. Furthermore, by partial methanolysis followed by methylation and suitable treatment of the hydrolytically resistant portion (containing 1.5% sulfate), they isolated 2,4-dimethyl-~-galactose (XIX). From CHiOH
k
I OMe
XIX
this they suggested that some 1 -+ 6 D-galactose linkages are present in addition t o the 1 --$ 3 linkages and that therefore the molecule has a branched chain. They also considered that a-D-linkages between the galactose residues were probable. The structure of 2,4-dimethyl-~galactose had already been determined by Smith.81 Recently, the work of Percival and coworkerss8was confirmed by Dillon and O'C~lla,'~ who likewise obtained 2,4,6-trimethyl-~-galactose and some 2,PdhnethyL~(79) T. Mori and S. Fumoto, J. Agr. Chem. SOC.Japan, 23, 81 (1949); Chem. Abstrack, 44, 7783 (1950). (80) W. Z. Hessid, J. Am. Chem. SOC.,67, 2046 (1935). (81) F. Smith, J . Chem. Soc., 1724 (1939).
338
T. MORI
galactose by the methanolysis of methylated desulfated carrageenin derived from the triacetyl derivative mentioned above. As to the disposition of the sulfate group, Hassid71argued, from the following considerations, that it is attached to C6 in the mucilage from the American I . laminarioides. The D-galactose unit has a pyranose ring and therefore the group attached to C6 must protrude from the ring. Owing t o the steric position of the group attached at this position, such a group will tend to be more reactive than other groups. Hence Hassid assigned the sulfate ester group to C6 as the most probable position. Moris2 could not tritylate C . ocellutus mucilage and thus favored the location of the sulfate group on C6. On the other hand, Percival and coworkers obtained 2,6-dimethyl-~-galactose (XX) from the methylated
l I o ~ 7 OH
H H
OhIe
xx products of the cold- and hot-water extracts of carrageens2vs3and from G. stellata mucilage. 2,6-Dimethyl-~-galactose(XX) had already been synthesized by Oldham and Bells4and its structure was further verified by Percival and coworkers62,66 who demonstrated that it gave 6-methylD-galactose phenylosazone and that the amide obtained from it exhibited a negative Weerman test. From these results and from the difficulty of alkali desulfation together with the establishment of the 1 3 3 linkage, Percival and coworkers62v66 located the sulfate ester group on C4 in the hot- and cold-water extracts of carrageen and in the mucilage of G . stellata. Thus XXI represents the main repeating unit in such a polysaccharide. CH2OH
XXI
These results indicate the desirability of reexamining the sulfate position allocation in the mucilages from I . laminarioides and C. ocellatus. (82) T. Mori, J. Agr. Chem. SOC.Japan, 23, 81 (1949); Chem. Abstracts, 44, 7783 (1950). (83) E. G . V. Percival and J. Buchanan, Nature, 146, 1020 (1940). (84) J. W. H. Oldham and D. J. Bell, J. Am. Chem. Soc., 60, 323 (1938).
SEAWEED POLPSACCHARIDES
339
Johnston and Percivale8 obtained 2,4,6-trimethyl-~-galactose from the hydrolytically resistant portion, [a],-50°, of carrageenin in a yield of 15% of the carrageenin. Thus it became clear th a t the L-galactose unit is also linked 1 3 in the same manner as are the D-galactose units. In addition t o 2,4,6-trimethyl-~-galactose (6 parts, identified as the crystalline anilide), they obtained tetramethyl-L-galactopyranose (2 parts, identified as the crystalline anilide), 2,4,6-trimethyl-~-galactose (2 parts), 2,4dhnethyl-~-galactose (4 parts), tetramethyl-D-galactopyranose (1 part), as well as trimethyl-D-xylopyranose (1 part). The amounts of 2,4,6-trimethyl-~-galactose and of tetramethyl-D-galactopyranose present were estimated from the rotations of the sirupy fractions, which consisted preponderantly of the L-form. The other proportions were obtained by quantitative paper chromatography and by cellulose column work. As noted above, the D-xylose derivative probably originated in a xylan contaminant. From these results, Johnston and Percivale8 postulated that carrageenin possesses a complex structure based on a resistant 1 + 3 linked backbone, rich in L-galactose residues, to which through C6 points of branching are joined 1 3 linked D- and L-galactose residues, the whole forming a basic hydrolytically resistant structure roughly one-sixth of the entire molecule. To the terminal units of this portion would be attached chains of 1 -+ 3 linked D-galactose units (XXI) carrying a sulfate ester group on C i . Alternatively, Johnston and Percivala8 suggested th a t carrageenin might be a mixture, with the hydrolytically resistant portion a separate polysaccharide. This conception of Johnston and Percival does not envisage a ketose or a 2-keto-~-gluconicacid portion. Such detailed studies as described above have not been carried out on the polysaccharides related to carrageenin. Further experimental work is required to give definitive solutions to the structures of the members of this group of marine plant polysaccharides. --f
--f
4. Hydrolytic Enzymes
Moria6found a carbohydrase fraction in t.he viscera, particularly the hepatopancreas, of Turbo cornutus (topshell) and of some other gastropoda,86which hydrolyzes C. ocellatus mucilage without producing any inorganic sulfate. Thus a preliminary desulfation by a sulfatase ia not required before a polyase attack, in contradistinction to a postulation by (85) T. Mori, J . Agr. Chem. SOC.Japan, 16, 1070 (1939); Chem. Abstracts, 34, 3285 (1940). (86) T.Mori, J . Agr. Chem. SOC.J a p a n , 19, 740 (1943); Chem. Abstracts, 46, 9089 (1951).
340
T. MORI
OppenheimerB7for agar. The carbohydrase of Mori is different from inulase, pectinase and probably from gelase.88 The latter difference need not be surprising if agar consists of P-n-glycosidic linkages and C . ocellatus mucilage possesses the a-D-combination, as already noted. The enzyme preparation is quite unstable even in the dry state, losing its activity on several days’ storage a t room temperature. At icebox temperature, the activity did not decrease measurably over a period of several months. The pH optimum was found to be about 4.0and the optimal temperature was about 40”.
V. FUCOIDIN 1. Composition
In 1890, Gunther and TollensSgrecorded that fucosan was present in the cell membrane of Fucus, a brown alga, from which fucose was produced on hydrolysis. Kylingo isolated a mucilaginous polysaccharide, composed mainly of fucose together with a little pentose, from Fucus vesiculosus, Laminaria digitata and Ascophyllum nodosum. He assigned the name fucoidin to it. Hoagland and Liebgl obtained a polysaccharide considered to be fucoidin from the giant kelp, Macrocystis pyrifera. Bird and Hamg2recognized combined sulfate in the fucoidin of Laminaria and subsequently Nelson and CretcheP also detected ester sulfate in giant kelp mucilage. The latter authors considered that fucoidin probably consisted only of L-fucose residues carrying ester sulfate groups, ROSOzOH, and that the uronic acid (2.6%) detected in the fucoidin preparations had its origin in contaminant alginic acid. Lunde, Heen and 6yg4prepared fucoidin from L. digitata and considered from analytical data that it had the general composition (ROSOzOM), wherein R is a carbohydrate radical consisting of 60 % L-fucose (but not uronic acid or pentose) and M is chiefly sodium together with potassium and very small amounts of calcium and magnesium. Percival and coworkersgKhave published a method for the estimation of combined fucose. Percival and Rossg6prepared fucoidin from Himanthalia Zorea as well (87) C. Oppenheimer, “Die Fermente und ihre Wirkungen,” Georg Thieme,
Leipzig, 1925,Vol. I, p. 716. (88) T. Mori and T. Okafuji, J . Agr. Chem. SOC.Japan, 16, 886 (1940);Chem. Ab8tTUCk, 36, 4399 (1941). (89) A. Gunther and B. Tollens, Ber., 23, 2585 (1890). (90) H. Kylin, 2.physiol. Chern., 83, 171 (1913);94, 337 (1915). (91) 0. R. Hoagland and L. L. Lieb, J . Biol. Chem., 23, 287 (1915). (92) G.M. Bird and P. Haas, Biochem. J., 26, 403 (1931). (93) W.L. Nelson and L. H . Cretcher, J . Biol. Chem., 94, 147 (1931). (94) G.Lunde, E.Heen and E. t)y, 2. physiol. Chem., 247, 189 (1937). (95) E. G.V. Percival and A. G. Ross, J . SOC.Chem. Ind., 67, 420 (1948). (96) E.G.V. Percival and A. G. Rosa, J . Chem. SOC.,717 (1950).
SEAWEED POLYSACCHARIDES
341
as from F. vesicuhsus, F. spiralis and L. cloustoni, and subjected it to intensive purification. Analysis of the highly purified specimen so obtained yielded the following analytical hydrolyzate percentage data (after making due allowance for adsorbed solvent) :fucose, 56.7; galactose, 4.1; uronic acid, 3.3; xylose, 1.5; SO,, 38.3; metallic cations, 8.2. The sulfate ash was found to be: Ca, 25.0; Mg, 1.9; Na, 1.1;K, 0.8; Sod, 73.2; these data differ from the findings of Lunde and associate^.^^ From these results it may be inferred that fucoidin is essentially a fucosan monosu!fate which is difficult t o obtain in a state free of asscciated carbohydrate contaminants. 2. Structure Conchie and Percivals’ found that the direct methylation of fucoidin with dimethyl sulfate and sodium hydroxide was more satisfactory than the simultaneous deacetylation and methylation of its acetyl derivative. Methylated fucoidin was hydrolyzed and the products were converted to their methyl glycosides. By chromatography on alumina there were isolated methyl L-fucosides (about 20 %), methyl 3-methyl-~-fucosides (57%) and methyl 2,3-dimethyl-~-fucosides (20 %). The structure of 3-methyl-cfucose (XXII) was ascertained as follows, H
OMe H XXII
It was shown to be a derivative of L-fucose by conversion into methyl 2,3,4-trimethyl-a-~-fucoside, which had been synthesized by Schmidt, Mayer and D i ~ t e l m a i e r . ~On ~ oxidation it yielded a lactone with constants comparable with those of 3-methyl-~-fuconolactone (digitonol a c t ~ n e ) , ~except ~ * ~ *that the sign of rotation was reversed. The amide obtained from the lactone gave a positive Weerman test, indicating that the hydroxyl of C2 was unmethylated. Furthermore, on a paper chromatogram it was indistinguishable from 3-methyl-~-fucosebut was separated distinctly from 2-methyl-~-fucoseprepared according to the method of MacPhillamy and Elderfield.gg The methyl dimethylglycoside in question was demonstrated to be the (97) J. Conchie and E. G . V. Percival, J. Chem. Soc., 827 (1950). (98) 0. T. Schmidt, W. Mayer and A. Distelmaier, A m . , 666, 26 (1944). (99) H. B. MacPhillamy and R. C. Elderfield, J. Org. Chem., 4, 150 (1939).
342
T. MORI
methyl glycoside of 2,3-dimethyl-~-fucose (XXIII) as follows. Further methylation yielded methyl 2,3,4-trimethyl-a-~-fucoside and consequently it must be a derivative of methyl a-L-fucopyranoside. The amide of the acid produced from the dimethyl ether exhibited a negative Weerman test, showing the presence of a methoxyl group on C2. The lactone of this acid was dextrorotatory whereas the lactonelooof 2,3,4trimethyl-L-fuconic acid is levorotatory. Hudson’s lactone rule would predict that a 1,4 or y-lactone of L-fuconic acid would be dextrorotatory and that a 1’5 or 8-lactone would be levorotatory. Thuq C4 is unmethylated. The methyl dimethylglycoside is markedly different in melting point and rotation from methyl 3,4dimethyl-a-~-fucoside,which was synthesized by the Percivals. lol The dimethyl sugar (XXIII) was subjected to successive oxidation with periodate and hypobromite ions to
HceF% Hooc
HO
OHCy
OMe H
OBr-
MeyCHO--r
OMe H
OMe H
XXIII XXIV yield ndhethoxysuccinic acid (XXIV), identified as the diamide. Such a n oxidation product could be obtained only if methoxyl groups were located on C2 and C3. Therefore the dimethyl ether is 2,3-dimethylL-fucose. The sulfate residue is alkali-stable and so cannot be esterified on a ring hydroxyl group located trans to an adjacent hydroxyl, since such a sulfate residue is alkali-labile102;therefore the union between L-fucose H
xxv units cannot be 1-+ 4 and the sulfate cannot be located on C2 or C3, which are sterically trans in the fucose configuration. The isolation of 3-methyl-~-fucoseleaves only one possible structure for the main L-fucose residues carrying one free (C3) hydroxyl group, namely, a 1--j 2 linkage with a sulfate ester group on C4 (XXV). As the rotations of fucoidin and (100) Sybil P. James and F. Smith, J. Chem. SOC.,746 (1945). (101) E.Elizabeth Percival and E.G. V. Percival, J . Chem. SOC.,690 (1950). (102) E.G. V. Percival, Quart. Revs. (London), 8, 369 (1949).
SEAWEED POLYSACCHARIDES
343
its derivatives are strongly negative, these 1 -+ 2 linkages are considered to be of the a-L-form. From the above delineated results, from the fact that unsubstituted L-fucose was a hydrolytic product of methylated fucoidin, and from the
proportions of the three L-fucose structures (L-fucose, 3-methyl-~-fucose and 2,3dimethyl-~-fucose) isolated, Conchie and Percivalg7postulated that fucoidin was constructed as shown in XXVI or XXVII. Further investigations, particularly on desulfated fucoidin, are
344
T. MORI
required before a definitive structure can be assigned. If XXVI were correct, the desulfated and methylated substance should yield on hydrolysis 2,3-dimethyl-~-fucose (from b, XXVI) and 3,4dimethyl-~-fucose (from a and c, XXVI). The same treatment applied to XXVII should yield 4-methyl-~-fucose (from b, XXVII), 3,4-dimethyl-~-fucose, and 2,3,4-trimethyl-~-fucose(from c, XXVII), no 2,3-dimethyl-~-fucosebeing possible. Furthermore, if the main linkage is 1 + 2, then 3,4-dimethylL-fucose would be the main hydrolytic product obtainable from the hydrolysis of such a desulfated and methylated fucoidin. VI. LAMINARIN Laminarin is the reserve carbohydrate of the sublitoral brown algae, especially Laminaria. There are two types of laminarin as regards solubility, the normal or water-insoluble laminarin (from L . cloustoni) and a soluble type (from L. digitata). These two kinds of laminarin differ only in solubility and are otherwise indistinguishable in composition and structure. They will not be further differentiated in this description. .
1 . Composition
Laminarin was discovered by Schmiedeberg.lo) Kreftinglo3 and Toruplo6 claimed that laminarin was soluble in warm water but was insoluble in cold water, gave glucose on hydrolysis and was levorotatory. Kylingoreported that laminarin was built up entirely of glucose. Gruzewskalo6claimed the occurrence of galactose, besides glucose, in the laminarin of L. Jlezicaulis but Colin and Ricard107found it to consist only of glucose, confirming the view of K~lin.~OBarry'O* discovered a simple method for preparing laminarin from L. cloustoni and inferred that it occurred in the seaweed as an ester sulfate. N i s h i ~ a w a ' isolated ~~ laminarin from Eisenia bicyclis and obtained 99.5 % of glucose on hydrolysis. Very recently, Connell, Hirst and Percival,llo and Percival and Ross,lll recognized 95% and 95.3 % of glucose, respectively, in the hydrolyzate of normal and soluble laminarin. Among the hydrolytic products of the latter they detected fucose (1.4%) and a small quantity of combined sulfate; the amounts of these were decreased on electrodialysis. (103)J. E.0.Schmiedeberg, Tagebl. d . Naturforscherversammlung, 231 (1885). (104) A. aefting, Tidsskr. Kemi, Farm. Terapi, 151 (1909);Pharmacia, 6, 161;
Chem. Abstracts, 4, 460 (1910). (105)s. Torup, Tidsskr. Kemi, Farm. Terapi, 153 (1909); Pharmacia, 6, 153; Chem. Abstracts, 4, 460 (1910). (106) Mme. Z.Gruaewska, Compt. rend., 170, 521 (1920);178,52 (1921). (107) H.Colin and P. Ricard, Compt. rend., 188, 1449 (1929). (108) V. C. Barry, Sci. PTOC.Roy. Dublin Soc., 21, 615 (1938). (109)K.Nishiaawa, J. Chem. Soc. Japan, 60, 1020 (1939). (110)J. J. Connell, E. L. Hirst and E. G. V. Percival, J . Chem. SOC.,3494 (1950). (111) E. G, V,Percival and A. G. Ross, J . Chem. Soc., 720 (1951).
SEAWEED POLYSACCHARIDES
345
From these results it is apparent that laminarin is composed entirely of glucose, the combined sulfate and fucose detected being due to admixture with fucoidin. 2. Structure On acetylation of laminarin followed by simultaneous deacetylation and methylation, Barry112 obtained methylated laminarin, among the hydrolytic products of which he identified 2,4,6-trimethyl-~-glucose CH20Me
I
I
H OMe XXVIII
XIII).113 From the negative rotation of laminarin, [aID- 13", ant its derivatives, it is probable that 0-D-linkages are predominant in the molecule. From this Barry suggested that P-D-glucose units are combined through 1 + 3 unions in laminarin. Connell, Hirst and Percival, l10 and Percival and ROSS"'isolated, from both normal and soluble laminarin, 2,3,4,6-tetramethyl-~-glucose, 2,4,6-trbnethyl-~-glucose, and 2,6and 4,6-dhnethyl-~-glucoses.The last two were considered to be derived from 2,4,6-trimethyl-~-glucose by demethylation. These results confirm the view of Barry112and a highly branched structure for laminarin appears to be excluded.
H
OH XXIX
Barry"* isolated a disaccharide, laminaribiose, on the partial hydrolysis of laminarin by enzymes (digestive juice of the snail Helix pomatia or H . aspersa) or by acid (seven hours with N oxalic acid on the waterbath). He showed that this disaccharide consisted solely of D-glucose and considered it to be 3-P-~-glucopyranosyl-~-glucopyranose(XXIX). (112) V. C. Barry, Sci.Proc. Roy. Dublin SOC., 22, 59 (1939). 68, 1360 (1934). (113) J. W.H.Oldham, J . Am. Chem. SOC., 22, 423 (1941). (114) V. C.Barry, Sn'. Proc. Roy. Dublin SOC.,
346
T. MORI
Freudenberg and v. Oertzen116 synthesized laminaribiose through the reaction between tetraacetyl-D-glucopyranosyl bromide and 1,2-isopropylidene-D-glucose, and Biichli and Perciva1116performed a more definitive synthesis by employing 1,2:5,6-diisopropylidene-~-glucose in place of 1,2-isopropylidene-~-g~ucose. Therefore it is beyond doubt that @+glucose units are joined together by 1 3 linkages in laminarin. Nishizawalogfound the molecular weight of laminarin to be 3514 by a cryoscopic method; this corresponds to a chain length of 21-22 D-glucose units. Barry,"' employing a periodate technique which was believed to oxidize only the non-reducing end groups, found a chain length of 16 units. Connell, Hirst and Perciva1,"O however, showed that both the reducing and non-reducing ends were attacked by periodate and that over-oxidation occurred with laminarin and laminaribiose. Consequently, the value of 16 D-glucose residues obtained by Barry required re-examination. Connell, Hirst and Perciva1,llO and Percival and Rossll' obtained tetramethyl-D-glucopyranose in amounts of 5 % and 5.1 %, respectively, from methylated normal and soluble laminarin. They employed filter paper chromatography"* and cellulose column technique^."^ Their results indicate a chain length of about 20 D-glucose units. Determinations of the average molecular weight of the methylated laminarin suggest that this chain may represent the true moleculel10 and is well in accord with the result of N i s h i ~ a w a . 1 ~If~this view is correct, the struchowture XXX may be assigned to laminarin. Percival and ever, assigned a value of 45 D-glucose units to normal laminarin and 112 to the soluble type, on the basis of hypoiodite consumption. Accordingly, XXX must be regarded with reserve. Kylingoconsidered that laminarin was a mixture of polymers of differing molecular size, while NishizawalOQbelieved that the laminarin of E. bicyclis was a single polysaccharide, since several fractions isolated by fractionation with methanol showed practically the same specific rotation. Percival and Rosslll examined normal and soluble laminarin and found no significant differences in their chemical structures (as mentioned above), their x-ray powder diffraction photographs, the amount of formic acid liberated by the successive action of periodate and hypobromite ions, and the molecular weights of their methyl ethers as estimated by --f
(115)K.Freudenberg and K. v. Oertzen, Ann., 674,37 (1951). (116) P.Bachli and E. G. V. Percival, J. Chem. SOC.,1243 (1952). (117) V. C.Barry, J. Chem. Soc., 578 (1942). (118) E.L. Hirst, L. Hough and J. K. N. Jones, J . Chem. SOC.,928 (1949). (119) L. Hough, J. K. N. Jones and W. H. Wadman, J. Chem. Soc., 2511 (1949).
347
SEAWEED POLYSACCHARIDES
the method of Caesar and coworkers.12o They did find that normal laminarin was about three times as reducing toward hypoiodite as soluble laminarin and about twice as reducing toward alkaline 3,5-dinitroCHiOH
n 12
H
-
ca. 18
OH
xxx salicylate.lZ1 Thus it is not clear why the laminarin of L. cloustoni is water-insoluble and that of L. digitata is water-soluble. 3. Hydrolytic Enzymes
Laminarase is found in malt,90the dried powder of several kinds of seaweed,122snail j ~ i ~ esea-hare , ~ (Tethys ~ ~ puntutu), * ~ ~l o g and ~ ~ in wheat, ~ ~ ~ potato, and hyacinth bulbs.lZ3
VII. OTHER POLYSACCHARIDER 1. Mucilage of Dumontia in crass at^^^*
This seaweed is a commonly occurring member of the family Dumontiaceae. The mucilage was prepared by extraction of the plant with2% hydrochloric acid followed by precipitation with ethanol. It consists of galactose and uronic acid residues carrying ester sulfate. Dillon and (SOe)s]. on the McKenna suggested the formula [(C~H1OO~)9(CSH60~) basis of analytical data; herein the ratio of sulfate group to sugar (including uronic acid) residue is 2:5. Periodate oxidation experiments led to a linkage assignment of 1 -+3 (with the possibility of some 1 -+ 4). (120) G. V. Caesar, N. S. Gruenhut and M. L. Cushing, J . Am. Charn. SOC.,69,
617 (1947). (121) K.H.Meyer, G. Noelting and P. Bernfeld, Helv. Chim. Acta, 31, 103 (1948). (122) A. R. Davis, Ann. Missouri Botan. Garden, 2, 771 (1915). (123) T.Dillon and P. o’colla, Nature, 166, 67 (1950);Chemistry & Industry, 29, 1 1 1 (1951). (124) T.Dillon and J. McKenna, Nature, 166, 318 (1950).
348
T. MORI
2. Algal Cellulose
Stanford126first found a substance similar to cellulose in seaweed and Mirande126 recognized cellulose in green algae. Kylingo and subsequently Naylor and R ~ s s e l l - W e l l sfound ~ ~ ~ normal cellulose in brown algae. On the other hand, Atsuki and Tomoda,lZ8and Ricard1Z9could not find normal cellulose in several kinds of seaweed. Dillon and O ' T ~ a m a 'proved ~~ the existence of normal cellulose in Laminariue by preparing the acetyl and methyl derivatives and examining their properties. Tadokoro and associates1a1reported that the cellulose of Iridaea laminarioides consisted of 9 1% a-cellulose. Araki and HashiIa2isolated cellobiose octaacetate on acetolysis of the cellulose from Gelidium Amansii in nearly the same yield as from standard cotton cellulose, establishing that algal cellulose is constructed of 1 + 4 linked 8-D-glucopyranose residues, as is the cellulose of higher plants. Likewise, Percival and Ross1aSdemonstrated the nature of algal cellulose by periodate oxidation and by its conversion to cellobiose octaacetate on acetolysis. Thus, algal cellulose consumed 1.02 moles of periodate ion per D-glucose residue, aa required by a 1-+ 4 linkage; a 1 .--t 3 linkage would have consumed no periodate and a 1-+ 6 linkage would require 2 moles per D-glucose unit. From the formic acid produced on periodate oxidation, they estimated the chain length of algal cellulose as 160 D-glucose units whereas that of their standard cotton cellulose yielded a value of 360 units. The x-ray diffraction diagrams of algal celluloses showed the characteristic pattern of normal cellulose. 3. Algal Xylan Barry and Dil10n'~~ prepared a polysaccharide from the red seaweed Rhodymenia palmata by extracting the plant with dilute hydrochloric acid and precipitating the product with alcohol. This substance gave (125) E. C. C. Stanford, J . Sac. Chem. Znd., 6, 218 (1886). (126) R. Mirande, Compt. rend., 166, 475 (1913). (127) G. L. Naylor and Barbara Russell-Wells, Ann. Botany (London), 48, 635 (1934). (128) K. Atsuki and Y. Tomoda, J . SOC.Chem. Ind. Japan, 29,509 (1926); Chem. Abstrack, 21, 115 (1927). (129) P. Ricard, Bull. SOC. chim. biot., 13,417 (1931). (130) T. Dillon and T. O'Tuama, Nature, 133, 837 (1934); Sci. Proc. Roy. Dublin Soc., 21, 147 (1935). (131) T. Tadokoro and K. Yoshimura, J . Chem. Sac. Japan, 66, 655 (1935); T. Tedokoro and N. Takasugi, J . Agr. Chem. Soc. Japan, 12, 421 (1936). (132) C. Araki and Y. Hashi, Collected Papers for the Celebration of the FoTty-$fth Anniversary of the Founding of Kyoto Technical College, 64 (1948). (133) E. G. V. Percival and A. G. Ross, J . Chem. Sac., 3041 (1949). (134) V. C. Barry and T. Dillon, Nature, 146, 620 (1940).
SEAWEED POLYSACCHARIDES
349
D-xylose on hydrolysis with dilute nitric acid. Percival and Ch~tnda7~ isolated a xylan from the same plant. They found that the methylated xylan produced on hydrolysis 2-methyl-~-xylose,2,3-dimethyl-~-xylose, 2,4-dimethyl-~-xyloseand 2,3,4-trimethyl-~-xylose. From this and from the results of periodate okidation, Percival and Chanda considered that the polysaccharide contains 1---f 3 and 1 4 linkages with a non-reducing for every 20-21 D-xylose endgroup (yielding the 2,3,4-trimethyl-~-xylose) units. They considered that this xylan was not a mixture of 1+ 3 and 1-+ 4 linked polysaccharides because careful fractionation of its diacetate and dimethyl ether failed to establish any polymer heterogeneity. Barry, Dillon, Hawkins and O ' C ~ l l aconfirmed ~~ the conclusion of Percival and Chanda. From these results, algal xylan appears to be analogous to lichenin, which is constructed of 1 -i3 and 1 4 linkages between D-glucose residues, and is thus different from the known x y l a n ~ of ' ~land ~ plants. --f
--f
4. Alginic Acid Alginic acid is a structural or supporting component in the brown algae. Nelson and CretcherlsB demonstrated that it yielded D-mannuronic acid on hydrolysis with acids. Methylation experiments's7 and periodate oxidation datals8 established it as a 1+ 4 P-D-linked mannuronic acid polymer. Frush and I ~ b e 1 1 reported '~~ a simple procedure for the preparation of the lactone of D-mannuronic acid from algin. Percival and associate^^^^^^^ have published a method for the estimation of alginic acid in seaweeds. 5 . Floridean Starch
Floridean starch is a reserve carbohydrate in red algae as laminarin is in brown algae. Starch or substances resembling it have long been known in seaweed. Without actually isolating pure substances, some i n ~ e s t i g a t o r have s ~ ~ asserted ~ ~ ~ ~ ~that Floridean starch is identical with (135) R.L. Whistler, Advances i n Carbohydrate Chem., 6 , 269 (1950). (136) W.L. Nelson and L. H. Cretcher, J . Am. Chem. SOC.,61, 1914 (1929);62, 2130 (1930). (137) E. L. Hirst, J. K. N. Jones and (Miss) W. 0. Jones, J . Chem. SOC.,1880 (1939). (138) H. J. Lucas and W. T. Stewart, J. Am. Chem. SOC.,62, 1792 (1940). (139)Harriet L. Frush and H. S. Isbell, J. Research Natl. Bur. Standards, 37, 321 (1946). (140) M. C. Cameron, A. G. Ross and E. G. V. Percival, J . SOC.Chem. Ind., 67, 161 (1948). (141) F.-W. Schimper, Ann. sci. nut. Botan., [7]6 , 77 (1887). (142)R. Kolkwitz, Wissenschaftliche Meersuntersuehzcngen, Ncue Folge, 4, Abt. Helgoland, 31 (1900).
350
T. MORI
normal starch and others90v143 have held that it is different. Colin and A ~ g i e r first l ~ ~ actually isolated Floridean starch from Lemania nodosa, a fresh water red alga, and reported that it produced a violet color with iodine, showed a specific rotation of [aID 105”,and yielded D-glucose on hydrolysis, K ~ l i n recorded ’~~ that Floridean starch from Furcellaria fastigiutu gave maltose on hydrolysis with dialyzed malt extract. Barry, Halsall, Hirst and Jones146found that Floridean starch from DiZsea edulis gave 95% of D-glucose on hydrolysis and resembled glycogen in being precipitable from aqueous solution on saturation with ammonium sulfate. They suggested the presence of both 1-+ 4 (60%) and 1 -+ 3 (40%) linkages since the Floridean starch consumed 0.6 mole of periodate ion per anhydro-D-glucose unit. From the high positive rotation, the glucose linkages are considered to be a-D.
+
6. Cyanophycean Starch
Several investigator^'^^-^^^ have worked with this starch and Kylinl6I reported that Cyanophycean starch (Cyanophyceenstarke) from the green alga Colothrix: scopuZorum, gave maltose with dialyzed malt extract. Kylin considered that Cyanophycean and Floridean starches were similar but not identical because of their differing colorations with iodine; the former developed a red brown color before and after boiling whereas the latter exhibited a yellow t o red brown color changing to red violet on boiling. (143) E.Bruns, Flora (Ger.), 79, 159 (1894). (144) H. Colin and J. Augier, Compt. rend., 197, 423 (1933). (145) H.Kylin, Kgl. Fysiograf. Stillskap. Lund, Forh., 13, No. 6, 1 (1943). (146) V. C. Barry, T. G. Halsall, E. L. Hirst and J. K. N. Jones, J . Chem. SOC., 1468 (1949). (147)L. Errera, ThBse, Bruxelles (1882);Rec. Znst. botan., T.1, Bruxelles (1906). (148) 0. Buschli, “Weitere Ausfiihrungen uber den Bau der Cyanophyceen und Bakterien,” Verlag Wilhelm Engelmann, Leipzig, 1896;Arch. Protistenk., 1,41 (1902). (149) R. Hegler, Jahr. wiss. Botan., 36, 229 (1901). (150) A. Fischer, Botan. Ztg., 63, 51 (1905). (151) H. Kylin, Kgl. Fysiograf. Sdlskap. Lund, Forh., 13, No.7 (1943).
Author Index Numbers in parentheses are footnote numbers. They are inserted to indicate the reference when an author’a work is cited but hir, name is not mentioned on the page.
A
Assaf, A. G., 20 Atsuki, K., 348 Augier, J., 350 Auk, It. G., 221, 222 Avenquin, J. B., 292 Avery, 0. T., 54, 65(50)
Aagaard, T., 280,281(11), 282(11) Adams, M. H., 146, 150(225), 158(219, 225), 159(219, 225), 161(225), 281, 289(18) Adams, R., 24 Adkins, H., 4, 33(8) B Ahmed, Z. F., 220, 225(16) Aichner, F. X., 68 Bllchli, P., 346 Akiya, S., 236, 237, 239(32) Bacon, J. S. D., 146 Alberda van Ekenstein, W.,19, 305 Baddiley, J., 50, 178, 179(333) Albon, N., 289 Baer, E., 83, 85(188), 101 Baeyer, A , , 251 Alekhine, A., 278, 279, 280 Alexander, B. H., 14, 43, 232, 243, 246 Balch, R. T., 294, 298, 300, 301(75), 306(18), 309 (14), 248(14) Alexander, J., 316 Balfe, M. P., 110, 123, 180(28) Barber, M., 262 Allen, E. W., 65 Allerton, R., 56, 79(61), 82, 83(180), 85, Bardolph, M. P., 10 Bardorf, C. F., 311 87(189a),89(61), 95(180), 103, 159 Barker, C. C., 19, 184 Amadori, M., 60, 98 Ambler, J. A., 298, 299(67), 309 Barker, G. It., 184, 186(362), 197(362) Ames, J. B., 25, 130 Barker, S. A,, 245, 246 Barnard, D., 69 Amiard, G., 65 Amoros, L., 243 Barnett, W.I,., 329 Andersen, W., 52 Barry, V. C., 315, 320, 328, 329, 330, Anderson, E., 232 335, 344, 345, 346, 347(114), 348, 349, 350 Anderson, I,., 294 Bartlett, P. D., 211 Anderson, R. H., 11 Bashford, V. G., 177 Angyal, S. J., 208, 209 Battelle, E. E., 304 Anno, K., 315 BAtyka, E., 213 Arai, K., 319, 333 Araki, C., 315, 318, 319, 320, 322, Bauer, H., 63 323(11), 324, 325,326, 333,348 Bauer, R. W., 317, 330 Baumann, E., 113 Arcangeli, I,., 234 Armstrong, E. F., 38 Beaber, N. J., 112, 115, 178 Beadle, G. W., 294 Arnold, H. E., 23, 30 Becker, J., 159 Ai-nolt, R. I., 258 Beckurts, H., 108 Arroyo, E., 312 Beensch, L., 94 Arts, N. E., 233 Behr A., 298 Asahina, Y.. 275 35 1
352
AUTHOR INDEX
Beijerinck, M. W., 290 Bell, D. J., 27, 29, 111, 124(34), 145, 146, 151, 154(34), 155, 156(249), 158(249),167(212), 186(34), 197(34), 217, 221, 289, 324, 338 Bennett, G. M., 121, 126(101) Bentley, H. R., 52 Berenbom, M., 274 Berend, G., 236 Bergell, P., 108 Berger, E., 101 Berger, L., 235 Bergis, R., 274 Bergmann, F., 274 Bergmann, M., 46,47,69,70, 72,73(117), 86(3), 88, 89(204), 91(6, 134), 92 (118),101(118), 108,235,248, 336 Bergstrom, C. G., 121 Bernfeld, P., 347 Bernoulli, A. L., 29, 126, 139(128), 141, 154(126) Berthelot, M., 278 Bertrand, G., 39 Besler, E., 125 Bial, M., 65 Biilmann, E., 201 Binkley, W. W., 17, 293, 294, 296(21), 297, 299, 304, 305, 306(88), 308, 311(70), 312 Bird, G. M., 340 Birkofer, L., 56 Black, A., 297 Black, C. L., 314 Bladon, P., 173,202,203(411),215 Blair, M. G., 294, 296(21), 305, 306(21), 311(97), 312(21) Blaise, E. E., 82 Blanchard, P. H., 289 Blanchfield, E., 10 Blay, H., 243 Blindenbacher, F., 69, 91 Block, P., Jr., 192 Block, R. J., 17 Blouin, R. E., F93, 305(10), 310(10), 311(10) Blum, F., 274 Blumenthal, E., 166 Bobbio, F. O., 312 Bock, L. H., 22 Bodycote, E. W., 28, 93, 160, 176(276)
Boeseken, J., 14, 15(43) Bohn, E., 181 Bollenback, G. N., 40 Bolliger, H. R., 69, 71, 78, 83, 86, 87, 94(170), 132, 140(146), 162, 164 (291), 165(291), 179(289) Bonastre, 277 Bonner, W. A., 10 Bordwell, F. G., 127 Borsche, W., 121, 124(99) Boschan, R., 7, 28 Bott, H. G., 225, 229 Bougault, J., 76 Boulud, R., 251 Bourjau, W., 120 Bourne, B. A., 292 Bourne, E. J., 17, 33, 48, 152, 158(253), 160, 189, 202, 204(378), 217, 236, 245, 246 Bourquelot, E., 279 Boyland, E., 275 Brady, T. G., 54 Brahm, C., 274 Braun, E., 28, 109, 116(19), 149(19), 154(19), 176(19) Braun, G., 280, 289 Brauns, F., 109, 161, 165(17), 169(17), 177(17), 179(17) Bray, H. G., 253, 260, 274, 275 Brazda, F. G., 269 Bredereck, H., 101, 181 Bretschneider, H., 130 Breuers, W., 69, 91(134) Brewster, J. F., 15 Bridel, M., 279,280,281(11), 282(11) Brigl, P., 5, 15, 36, 36, 86, 101, 118, 144, 148(196), 200, 237 Broeg, C. B., 298, 309 Brooksbank, B. W. L., 262 Brown, D. M., 51, 62(27) Brown, J. B., 300 Brown, R. L., 87 Brown, W. G., 83 Browne, C. A., Jr., 293, 294, 296, 305(10, 15), 310(10), 311(10) Browne, J. S. L., 253, 275 Bruce, G. T., 189, 204(378) Bruck, W., 116, 121(68) Bruns, E., 350 Buchanan, J., 332, 334(62), 336(62), 338
AUTHOR INDEX
353
Clark, R. K., Jr., 28 Clark, V. M., 186 Clemens, P., 275 ClBve, P.-T., 108 Cleveland, E. A., 241 Clowes, R. C., 274 Coghill, R. D., 49, 50 Cohen, S. L., 275 Cohen, S. S., 55, 57, 58, 59, 60 Cohn, W. E., 49, 52, 74(14) Coleman, G. H., 9, 10 Colin, H., 344, 347(107), 350 Colley, A., 125 Collins, D. V., 74 Col6n, A. A., 243 Colowick, S. P., 67 C Colvin, J. R., 331 Caesar, G. V., 347 Compton, J., 22, 24, 25, 26, 129, 137, Caille, E., 257 144(171), 146, 148(171), 154(171), Caldwell, C. G., 37, 148 156, 158(134), 159(134), 162, 168, Cameron, M. C., 349 169(290, 307) Campbell, J. C., 263 Conaway, R. F., 20 Cantor, S. M., 298 Conchie, J., 341, 343 Carlson, A. S., 278, 282, 283(3), 285(3), Conley, M., 138 287(3), 290 Connell, J. J., 344, 345, 346 Carrb, M. H., 293 Comer, J. A., 259 Carson, J. F., 197, 213(394) Cook, W. H., 331 Carter, C. E., 52 Cooley, G., 98 Carter, H. E., 28 Cooper, G. D., 127 Cassella, L., 114, 115(48) Corbett, W. M., 202 Cassidy, H. G., 17 Cori, C. F., 103 Caswell, M. C., 298 Cori, G. T., 103 Cattelain, E., 76 Cortese, F., 72 Cavalieri, L. F., 306 Cottrell, T. L., 322 Centola, G., 32 Couch, D. H., 241 Chabrier, P., 76 Coutsicos, G., 236, 239(32) Chakravarty, S. N., 115, 116(60), 121 Cowgill, G. R., 308 (60) Cramer, F. B., 30, 34, 35, 69, 72, 126, Challenger, F., 69 197(129) Challinor, S. W., 324 Crbpieux, P., 116 Chancel, G., 108 Cretcher, L. H., 113, 121, 146(40), 188, Chanda, S. K., 335, 349 189, 192(364), 193, 201, 205, 206 Chapman, J. H., 112, 140(35), 214, (364), 209(364), 211(390), 214(364), 215(35) 340, 349 Chargaff, E., 41, 49 Crismer, R., 258, 263(46) Chatterjee, N. G., 300 Cunneen, J. I., 329 Chiozza, L., 108 Clapp, M. A., 113, 127, 188, 146(40), Cunningham, K. G., 52 192(364), 205, 206(364), 209(364), Cushing, M. L., 347 Cutler. W. 0.. 176 210(131), 214(364)
Buchler, C. C., 24 Buckles, R. E., 28 Buckley, M. I., 23, 24, 37 Bueding, E., 258, 260, 263 Buehler, H. J., 262 Burkhart, O., 28, 109, 116(19), 149(19), 154(19), 176(19) Burt, W., 229 Busch, M., 242 Biischli, O., 350 Butler, C. L., 121 Butler, G. C., 259 Butler, K., 97, 98(223) Butler, M. R., 336 Byall, S., 309
354
AUTHOR INDEX
D Daiber, K., 275 Dalmer, O., 43, 232, 243 Danehy, J. P., 307 Danielli, J. F., 61, 64 Danilov, S. N., 28 Dansi, A., 97 Dasa Rao, C. J., 299 Dauben, W. G., 287 Davenport, H. A., 64 Davis, A. R., 347 Davis, H. A., 14, 200 Davis, P. C., 146,202(215), 203(215) Davoll, J., 72, 79, 92, 99 Day, J. N. E., 110, 180(28) Dedonder, R., 289 Deerr, N., 292, 303 Degering, E. F., 242 Dehn, W. M., 134, 137(159) Deichmann, W. B., 253 Dekker, C. A., 49, 50, 52 De Meio, R. H., 258 Deplanque, R., 179 Deriaz, R. E., 54, 55(48), 57(48), 64(48), 68, 69, 70(112), 92(141), 93(141), 94(141), 95(141), 96(141), 97(112), 99(112), lOO(141) de Stevens, G., 299 de Tomasi, J. A., 61 Deulofeu, V., 36 Dewar, E. T., 200, 333, 334(66), 335(66), 336 Dewar, J., 151 Dhar, M. L., 127 Dickey, F. H., 8, 176 Dickhauser, E., 117, 128(73), 131(73), 135(73), 136(73), 139(73), 143(73), 145(73), 151(73), 158(73), 159(73), 171 Dickson, A. D., 294 Diehl, H. W., 140, 147(180), 160(180), 2 13(180) Dillon, T., 10, 315, 320, 328, 329, 330, 334,335,336,337,347,348,349 Dimler, R. J., 14, 200, 328 Dippold, H., 234 Dische, Z., 53, 65 di Somma, A. A., 274 Di Stefano, H. S., 61, 63(69)
Distelmaier, A., 341 Dodgson, K. S., 274 Doerschuk, A. P., 2, 259 Doisy, E. A., 262 Doisy, P. P., 262 Doniger, R., 49 Doser, A., 109, 165, 175(297), 177(25) Doughty, M. A., 123 Dounce, A. L., 55 Downing, M. L., 25, 129 Drahowzal, F., 115, 117, 135(74), 137 (74), 179, 181(335), 211(335), 212 (335) Drefahl, G., 41,232,239,240(12) Dressler, H., 26, 143, 145(190), 148(190), 150(190), 152(190), 154(190), 161 (190) Drew, H. D. K., 228, 229(50) Dreywood, R., 66 Drisko, R. W., 10 Duchateau, G., 258, 263(46) Duff, R. B., 171, 172, 319 Dumazert, C., 30, 248 Durin, E., 295 Durso, D. F., 17 Dvonch, W., 44 Dwyer, I. M., 298 Dyer, E., 23, 30 Dziewiatkowski, D. D., 258
E Eaken, R. E., 308 Earley, E. B., 295 Edward, J. T., 66 Ehrenberg, J., 101 Ehrlich, F., 240 Einhorn, A,, 35 Eisenberg, F., Jr., 259 Eldcrfield, R. C., 46, 53, 66(1), 90, 140, 147, 341 Elliott, E. C., 259 Ellis, B., 98 Elmore, D. T., 49 Ely, J. O., 64 Endoh, E., 276 English, J., Jr., 147, 211(233) Erb, C., 307 Erdmann, H., 115 Erilinne, D., 202
AUTHOR INDEX
355
Fischer, H. 0. L., 46, 73, 83, 85(188), 101, 135, 146, 175(218), 188, 275 Fishman, L. W., 263 Fishman, W. H., 246,252,262,263 Flatow, L., 274 Fletcher, H. G., Jr., 5, 25, 27(13), 35, 130, 171, 208, 212, 285, 294 Florkin, M., 258, 263 Fliickiger, F. A., 330, 333 Foldi, Z., 109 Folkers, K., 163 Forbes, I. A., 146, 148(221), 154(221), 318, 319, 324, 325(9) Fort, C. A., 296, 298, 301, 307, 314 Fort, G., 151 Foster, A. B., 69, 70(128), 83, 91(128), 97(128), 98(128), 101, 136, 146(169), 151(169), 171(169), 184, 193(1691, 196(169), 200, 203, 204(382) Foster, G. E., 109 F Fournier, P. L.-E., 118, 166(81), 197(81), 213(81) Fairbourne, A., 109 Fowler, W. F., Jr., 42, 241, 242(53) Farber, M., 296, 308(39) Franke, W., 113, 115(27) Farley, F. F., 248 Franel, R. E., 41 Farnell, R. G. W., 293, 294(11) Fraeer, J. C., 180 Farrer, K. R., 38, 101 Fred, E. B., 296 Fashena, G. J., 251 Freeland, E. C., 296, 299(34), 311(34) Faure, C., 147 French, D., 290 Fear, C. M., 19 Freudenberg, K., 27, 28, 87, 109, 114, Fellers, C. R., 323 116(16, 19), 124, 127, 134, 135(16, Felton, G. E., 68, 248 19, 122), 138(121, 122), 145(16), Fennyvessy, B. von, 274 147(16), 148(16), 149(16, 19), 152, Fernandez-Garcia, R., 243 153, 154(19), 158(16), 161, 165, 169, Ferns, J., 110, 117(26), 118(26), 127(26), 175(297), 176(16, 19), 177(17, 25, lSO(26) 122), 178, 179(17), 180, 181, 186, Feske, E., 121, 124(99) 214(252), 322, 346 Feulgen, R., 61, 63, 64 Freudenberg, W., 68, 88, 89(204) Fevilherade, L., 294, 306(17) Frew, J., 116 Fichter, F., 139 Friedeberg, H., 28 Fickett, W., 8, 176 Friedkin, M., 104 Field, L., 139 Friedman, 0. M., 135 Fieser, L. F., 13, 48 Friedmann, E., 27, 111, 124(34), 154(34), Fieser, M., 13 186(34), 197(34) Fikentscher, H., 127 Fromm, E: , 275 Findley, T. W., 300 Frush, H. L., 5, 6, 15, 143, 349 Finkelstein, H., 180, 201 Fukuda, M., 64 Fischer, A., 350 Fischer, E., 2, 3, 10, 18, 38, 46, 48, 68, Fumoto, S., 337 69(3), 70, 72, 79, 86(3), 94, 108, Funk, A., 21 Furburg, S., 50 231, 233, 252, 257
Erlbach, H., 117, 124, 130, 149, 153(138, 242), 154(138, 242), 155(138, 242), 156(242), 170(242) Errera, L., 350 Escher, E., 22 Estborn, B.. 52 Euler, E., 4, 28, 124, 135(114), 141, 149(200), 151(200), 152(114, 200), 155(200), 158(200), 159(114,200) Euler, H. von, 65 Evans, E. F., 47 Evans, R. N., 309 Evans, T. H., 295 Evans, W. L., 287 Evans, W. P., 10 Eveking, W., 21, 123, 124(109), 146 (log), 148(109), 159(109), 197(109) Evelyn, K. A., 253
356
AUTHOR INDEX
Furuichi, M., 323 Fuson, R. C., 63
G Gakhokidee, A. M., 46, 68, 69 Gall, D., 29, 146, 161(223) Gallagher, D. M., 239 Garcia y Gonzalea, F., 236, 239(32) Gardner, T. S., 30, 35(118), 132, 144, 190(195), 197(148) Garner, H. K., 8 Garthe, E., 21 Carton, G. A., 274 Gaver, I(. M., 21, 22(67), 38 Gehrke, M., 68 Genghof, D. S., 290 George, R. W., 87 Georgescu, M., 113 Georgi, E. A., 23 GereEs, A., 224 Gerhardt, C., 108 Gericke, H., 111 Gerrard, W., 123, 212, 213(424) Gilbert, V. E., 113 Gill, R. E., 329 Gill, R. F., Jr., 308, 312 Gillespie, D. T. C., 135 Gilman, H., 112, 115, 178 Gladding, E. K., 14, 37 Glioaai, E., 20 Gniichtel, A., 25, 27, 109, 111(24), 125 (24), 137(24), 139(24), 142(24), 148(24), 152(24), 154(24), 195(24), 212, 214(24) Godchaux, L., 303,309 Goebel, W. F., 99, 146, 150(225), 158 (219, 225), 159(219, 225), 161(225), 255, 256 Goepp, R. M., Jr., 5,27(13), 39, 101, 189, 208, 256, 262, 305 Gomberg, M., 24 Goodman, I., 86 Goodrich, R. W., 184,186(362), 197(362) Goodyear, E. H., 221, 228, 229(21,50) Gootz, R., 111, 142(33) Gosselin de Beaumont, L. A., 66 Gottlieb, D., 37, 148 Gould, C. W., 8 Graham, A. F., 246, 262
Green, A. A., 103 Green, C., 49 Green, J. W., 43, 44(180), 92, 231 Greene, R. D., 229, 297 Greenleaf, C. A., 310 Griebel, R., 26, 143, 145(190), 148(190). 150(1QO), 152(190), 154(190), 161 (190) Griffith, C. F., 132, 153(145) Grignard, V., 82 Grob, C. A., 69, 157 Gross, D., 289 Gruber, 0. von, 108 Gruenhut, N. S., 347 Grundherr, G. E. Von, 279, 280, 281(9), 282 (9) Griiner, H., 5, 15, 35, 36(47), 118, 144, 148(196), 208, 237 Griinler, S., 148, 153(239), 154(239), 161(239) Griissner, A., 234, 236(24) Grueewski, Z., 344, 347(106) Gulland, J. M., 50, 101 Gump, W., 55, 56(58) Gunness, M., 298 Giinther, A., 340 Giinther, E., 3, 4 Gurin, S., 64, 259 Gut, M., 78, 89, 140, 184 Guttmann, R., 240 Guyot, O., 56 Gyr, M., 77, 132, 140(151)
H Haas, H., 140 Haas, P., 316, 330, 332(5&), 334, 335, 336, 340 Ham, R. H., 20 Hackl, A., 31 Hadecke, J., 330 Hrteseler, G., 28 Hafea, M. M., 121, 126(101) Hager, F. D., 310 Haggis, G. A., 140 Hahn, F. L., 115 Hahn, L., 65 Halsall, T. G., 350 Hamdiiinen, J., 261, 275 Hamamura, Y., 189
AUTHOR INDEX
Hamaraki, Y., 64 Hamilton, D. M., 287 Hammarsten, E., 50 Hands, S., 318, 319, 323, 324 Hann, R. M., 14, 27, 39, 40, 81, 120, 124, 136, 138, 140, 144, 147, 151, 157, 158, 160(180), 171(173), 188, 189, 193 (377), 196, 197(170, 371, 376), 203 (369), 204(266, 273), 205(251), 208, 213(180), 218, 219 Hans, M., 290 Hardegger, E., 26, 81, 121, 131, 148, 154(142), 155(237), 156(142, 237), 158, 171(237), 176(272), 240, 241 (48), 256, 257 Harder, M., 127 Hardy, F., 303 Hardy, V. R., 166 Harris, S. A., 163 Harrison, F. C., 290 Hartles, R. L., 274 Harvey, W. E., 132 Hashi, Y., 348 Haskins, J. F., 166, 306 Haskins, W. T., 81, 120, 138, 147, 151, 157(251), 158(251), 171(173), 189, 196, 197(371), 205(251), 208, 21.8, 219(7) Hadewood, G. A. D., 262 Hassid, W. Z., 334, 337, 338 Hata, S., 274 Hatch, G. B., 4, 33(8) Hauenstein, H., 77, 83(169), 90, 157, 158(271), 196(271) Hauss, H., 219 Hawkins, B., 335, 349 Haworth, W. N., 3, 28, 62, 69, 93, 131, 135, 148(143), 151(164), 152, 154 (143), 160, 161, 176(276), 220, 221, 222, 224, 225,226, 228, 229, 319,324, 325(17), 336 Hayashi, K., 318, 323(12) Hayes, F. N., 120 Haynes, D., 293 Hayward, L. D., 37 Heard, R. D. H., 275 Heath, M., 130, 134(137), 197(137) Heath, R. L., 221, 224(23), 225, 229(23) Heddle, W. J., 18, 21 Heen, E., 340, 341(94)
357
Hegler, R., 350 Hehre, E. J., 278, 282, 283, 285(3), 287, 290, 295 Heidt, L. J., 14 Heinemann, R., 243 Heinrich, H., 247 Heiss, H., 219 Helferich, B., 3, 4, 16, 25(50), 26, 27, 35(94), 68, 86, 109, 111, 125, 130, 135, 137(24), 139(24), 142(24, 33), 143, 145, 148, 150, 152(24, 1901, 153(239), 154,156(18), 159, 160,161, 168(18), 175, 181, 184, 190(208), 195(24), 212, 214(24), 238, 290 Helferich, L., 238 Hemingway, A., 259 Hendricks, B. C., 230 Henry, L., 82 Hepp, H., 124 Herbert, J. B. M., 166 Heraog, W., 115, 166(56) Heslop, D., 224 Hess, H. V., 28, 134 Hess, K., 21, 28, 29, 30, 32, 38, 108, 116 (7), 119, 122, 123, 124, 125, 136(105, 117), 139(105), 146(108, log), 147, 148, 150, 151, 152(82, 124), 154(124, 240), 155(82, 124), 159(108, log), 166(105), 178(158), 193(240), 196 (117), 197(7, 109, 240), 212(240) Heubner, W., 295 Heumann, K. E., 28, 147, 151 Heuser, E., 130, 134(137), 197(137) Heyns, K., 35, 43, 232, 243 Hibbert, H., 290, 295 Hilbert, G. E., 14, 190, 200, 285 Hildebrandt, H., 257 Ilillary, B. B., 63 Hiltmann, R., 109, 154, 161(23) Himmen, E., 181, 212(346) Hinsberg, O., 113 Hirsch, P., 20, 242 Hirst, E. L., 2, 3, 19, 28, 69, 93, 147, 152, 160, 176(276), 184, 220, 221, 222, 224, 225, 226, 228, 229, 293, 324, 329, 344, 345, 346, 349, 350 Hixon, R. M., 37, 125, 134(122), 135 (122), 138(122), 148, 177(122), 248 Hixson, A. W., 247 Hoagland, C. L., 55
358
AUTHOR INDEX
Hoagland, D. R., 340 Hobday, G. I., 101 Hobold, K., 61 Hockett, R. C., 5, 25, 27(13), 35, 74, 85, 129, 130, 138, 146, 171, 184, 208, 219, 244, 308 Hodge, J. E., 33 Hoff-Jgrgensen, E., 104 Hoffman, M. M., 275 Hofmann, E., 262 Hofmann, K. A., 61 Hogsed, M. J., 306 Hollandt, F., 35 Holt, N. B., 15 Holven, A. L., 304 Honeyman, J., 136, 146(167), 197 Honig, M., 44 Honig, P., 295, 304 Hood, D. B., 64 Horecker, B. L., 38 Hotchkiss, R. D., 49, 256 Houben, J., 242 Houet, R., 258, 263(46) Rough, L., 67, 68(105), 83, 346 Houghton, A. A., 115, 166(57) Houssa, A. J. H., 167,211(305), 212(305) Howard, G. A., 246 Howard, J. P., 86 Huber, H., 132, 140 (153) Hiibner, H., 108, 167(3) Hlibner, R., 116 Huckel, W., 214 Hudson, C. S., 9, 14, 16, 27, 39, 40, 52, 81, 85, 88, 92, 93, 94, 99, 120, 124, 133, 136, 138, 140, 144, 147, 151, 157, 158, 160(180), 171, 184, 188, 189, 193(377), 196, 197(156, 170, 371, 376), 203(369), 204(266, 273), 205(251), 213(180), 218, 219, 233, 248, 277, 279, 280, 281, 282, 283, 285, 287, 289, 342 Huggins, C., 246 Hughes, E. D., 127, 167, 211(305), 212 (305) Hughes, I. W., 62, 69(76), 70, 91(76), lOO(76) Humboldt, E., 310 Humphris, B. G., 253, 260 Hutchinson, S. A., 52
I Ibhfier, J., 330 Iboff, A., 86 Iohihara, K., 274 Imaki, T., 311, 312 Ingold, C. K., 110, 127, 180(28) Irvine, J. C., 19, 180, 222, 228, 229, 230 Isbell, H. S., 5, 6, 15, 69, 72, 98, 99, 143, 161, 349 Iselin, B. M., 27, 69, 70, 89, 120, 146, 157(226), 158(226), 179(226) Isherwood, F. A,, 221, 224, 226(23), 229(22) Ishidate, M., 238, 261, 275 Ivers, O., 109, 114, 116(16), 134(16), 145(16), 147(16), 148(16), 149(16), 152(16), 153(16), 158(16), 161(16), 169(16), 176(16) Iwadare, K., 248 Izard. E. F., 179 Ismail’skii, V. A., 113
J Jackson, D. R., 113 Jackson, E. L., 248 Jackson, J., 62, 131, 148(143), 154(143), 319, 325(17) Jackson, W. R., 296 JaffB, M., 231, 251, 275 James, S. P., 145, 172(206), 342 James, W. J., 290 Jaworsky, W., 108, 112(4) Jeanlos, R. W., 70, 71, 75, 89(162, 163) Jenssen, F., 108, 167(3) Jochinke, H., 145, 150, 154(243), 161 (208), 190(208) Johnson, J. M., 287 Johnson, T. B., 49, 50 Johnston, G. G., 23 Johnston, R., 333, 335, 337, 339 Jolles, A., 247 Jones, D. B., 296 Jones, J. K. N., 19, 67, 68(105), 144, 147, 184, 220, 221, 224, 225, 226, 229(40), 231, 293, 329, 346, 349, 350 Jones, W. G. M., 319, 322, 325, 326, 327, 328 Jones, W. O., 349
359
AUTHOR INDEX
Josephson, K., 4 Joshi, S. S., 115, 116(60), 121(60) Jucker, O., 26, 131, 148, 154(142), 155 (237), 156(142, 237), 158, 171(237), 176(272) Jung, H., 55, 68(57), 74(57) Junger, A., 238 Just, F., 144, 151(193)
K Kahl, R., 108 Kaiser, E., 297 Kalckar, H. M., 103, 104 Kalle, W., 108 Kamil, I. A., 274, 275 Kaplan, N. O., 67 Karrer, P., 21, 22, 27, 9, 1 6, 148, 164, 165, 202(215), 203(215), 204(236) Karunairatnam, M. C., 263 Kary, Charlotte von, 218 Kastle, J. H., 180 Katsuyama, K., 274 Kateman, P. A., 262 Keenan, G. L., 309 Keller, C. C., 66 Kenner, G. W., 163, 164(294), 246 Kent, P. W., 52, 81, 93, 144, 221 Kenyon, J., 110, 123, 167, 179(305), 180(28, 305), 211, 212, 213(424), 214 Kenyon, W. O., 42, 120, 126, 127(95), 132(127), 232, 241, 242 Kerr, L. M. H., 246, 262, 263 Kerr, R. W., 42, 242 Khym, J. X., 14, 15(44), 52 Kiliani, H., 46, 66, 85, 233 Kimberly, J., 108 King, C. G., 259 Kinze, L., 125, 152(124), 154(124), 155(124) Kirshen, H. R., 212 Kita, G., 114, 115(52), 116(52) Kitabatake, T., 25, 35(94) Klages, F., 225, 229(37, 38) Klamann, D., 115, 117, 135(74), 137(74), 179, 181(335),211(335), 212(335) Klein, J., 238 Klein, W., 3, 51, 135, 160 Kline, E., 31
Knauf, A. E., 219 Knopf, E., 125, 138(121) Knorr, E., 6, 153 Knox, L. H., 211 Koenigs, W., 6, 153 Koerner, J. F., 52 Kolkwitx, R., 349 Koller, I., 135, 136(163), 167(163) Kondo, M., 69 Konigsberg, M., 101 Kortachak, H. P., 312 Kossel, A,, 274 Kostanecki, S. von, 275 Kosterlitr, H. W., 146 Kowkabany, G. N., 297, 308(43) Krafft, F., 112 Krefting, A., 344 Krehl, W. A,, 308 Kretschmer, E., 274 Kuhn, R., 97, 275, 279, 280, 281(9), 282(9) Kulka, M., 122 Kule, E., 275 Kylin, E., 315, 340, 344, 347(90), 348, 350 L
Lackmann, D. B., 55, 80(51) Laidlaw, R. A., 217, 289 Laird, B. C., 197 Lake, H. J., 274, 275 Lake, W. H. G., 160 Laland, 5. G., 49, 50, 52, 69, 88, 97, 184, 195(356) Lampen, J. O., 50, 65, 103, 104, 105(243) Lang, O., 184 Langdon, W. K., 113 Langer, A. W., Jr., 307 Langguth Steuerwald, L. G., 299 Lapworth, A., 110, 117(26), 118(26), 127(26), ISO(26) Lardy, H. A., 188, 294 Lasure, E. P., 21, 22(67), 38 Lauer, K., 20, 32 Lauritzen, J. I., 298 Lavin, G. I., 55 Lawrow, D., 275 Leavenworth, C. S., 294 Leohinsky, W., 47, 69(6), 91(6), 92(118), lOl(118)
360
AUTHOR INDEX
Leckzyck, E., 17, 18(53), 31, 32 Lee, J., 144, 190(195), 235 LefBvre, K. U., 294 Lehmann, V.. 274 Lehr, H., 248 Leitch, G. C., 280, 281(15), 289 Lepine, R., 251 Leslie, I., 263 Lesnik, M., 274 LeStrange, R., 17 Leulier, M. A,, 257 Leutgoeb, R. A., 247 Levene, P. A., 26, 35, 51, 55(30), 62(26), 68(31), 69(30), 72, 101, 123, 124, 125, 128, 129, 135(133), 144(111), 145, 146, 155(123), 156, 158(134), 159(133, 134), 161, 162, 166, 168, 169(290, 307), 178, 179(111), 184, 190, 193(133), 195, 196, 197(361), 200, 201, 229 Levi, A. A., 275 Levi, I., 288, 290 Levvy, G. A., 246, 258, 260, 262, 263 Lew, B. W., 189, 305 Lewis, H. B., 258 Lewis, W. L., 229 Lhotka, J. F., 64 Li, C., 63 Lichtenberger, J., 147 Liohtenstein, R., 4, 124, 135(114), 152 (114), 159(114) Lieb, L. L., 340 Lieser, T., 17, 18(53), 21, 31, 32, 35, 36(146), 131 Lin, C.-H., 120 Link, K. P., 236, 237(34), 294, 328 Linstead, R. P., 287 Lippmann, E. 0. von, 292, 312 Lipschitz, W. L., 258, 260, 263 Lishanskii, I. S., 28 Littmann, O., 94, 123, 146(108), 148, 150 (108), 154(240), 159(1081, 193(240), 197(240), 212 (240) Ljubitsch, N., 122, 123, 136(105), 139 (105), 166(105) Lobry de Bruyn, C. A., 19, 305 Loeffler, P., 46, 85 Loewenthal, O., 115 Lohmar, R., 39, 295, 328 London, E. S., 51
Lorand, E. J., 22, 23 Lorber, J., 146 Low, I., 275 Low, W., 197 Lowa, A., 125 Lucas, H. J., 8, 176, 349 Ludewig, S., 69 Lunde, G., 340, 341 Lythgoe, B., 51, 62(27), 72, 79, 92, 99, 246
M Macbeth, A. K., 135 Macek, T. J., 296 Machemer, H., 336 Mack, G. E., 275 Maclay, W. D., 158, 197, 204(273), 213(394) MacLeod, C. M., 54, 65(50) MacPhillamy, H. B., 147, 341 Maehly, A. C., 77, 132, 140(152), 160(152), 179(152), 180(152) Magasanik, B., 41 Magnus-Levy, A,, 255, 256, 275 Maher, J., 290 Mahoney, J. F., 22, 23, 29, 30, 132, 197(148) Maillard, L.-C., 307 Makino, K., 62, 68, 178, 179(332) Malerczyk, W., 28 Malm, C. J., 197 Mamalis, P., 98 Mandl, I., 290 Mandour, A. M. M., 127 Manson, L. A., 65, 103, 104, 106(243) Manson, W., 52 Mhrcker, C., 108 Marecek, V., 119, 120, 149(85), 152(85), 154(85), 155(85) Marini-Bettblo, G. B., 330 Markarova-Zemlyanskaya, N. N., 35 Marrian, G. F., 275 Marsh, C. A., 245, 256 Martin, L. F., 294, 298, 306(18), 310(66), 314 Martin, G. J., 258 Marvel, C. S., 120, 212(93), 298, 310, 314 Masamune, H., 262, 274
AUTHOR INDEX Mrtson, R. I., 138 Mathers, D. S., 147, 152(230) Matheson, N. K., 208, 209 Matsui, H., 323 Mataushima, Y ., 39 Maugham, G. B., 253 Maurer, K., 41, 232, 239, 240(12) Maw, G. A., 127 Mayer, P., 251, 253(2) Mayer, W., 341 Mazur, A,, 274 McCarty, M., 54, 65(50) McCasland, G. E., 5, 28 McCleskey, C. S., 309 McCloskey, C. M., 9 McEvoy-Bowe, E., 54 McGee, P. A., 42, 241, 242(53) McGettrick, W., 320 McKaig, N., 301 McKenna, J., 328, 329(47), 347 McMahan, J. R., 297 McNeely, W. H., 305 McNicoll, D., 230 McSweeney, G. P., 133 Mehltretter, C. L., 14, 43, 44, 190, 201, 210, 232, 235, 236, 238, 240, 241 (471, 243, 245, 246, 247, 248(14) Meisenheimer, J., 55,68(57), 74(57) Mejbaum, W., 65 Mellies, R. L., 43, 190, 210, 232, 243, 246(14), 248(14) Mench, J. W., 242 Menon, B. K., 180 Menaies, R. C., 19 Mering, J. von, 251, 275 Mers, V., 212 Metcalf, E. A,, 123, 166(106), 197(106), 306 Metaler, A., 61 Meyer, A. S., 69, 151, 162, 173(288) Meyer, G. M., 229 Meyer, H., 139, 231, 251, 257 Meyer, K. H., 347 Michalski, J. J., 132 Micheel, F., 9, 89, 94, 151, 152(247), 156, 158(247) Micheel, H., 9 Mickelson, M. N., 308 Mikeska, L. A., 51, 68(31) Milhorat, A. T., 296, 308(39)
361
Miller, C. O., 259 Miller, R. E., 146, 244, 298 Miller, S. E., 23, 24, 37 Mills, G. T., 262, 623 Mills, J. A., 134, 135, 137 Millstein, C. H., 309 Milman, A. E., 296, 308(39) Mirande, R., 348 Miriam, S. R., 275 Mirsky, A. E., 54, 64 Misani, F., 49 Mittag, R., 175 Moe, 0. A., 23, 24, 37 Montavon, R. M., 26, 81, 121, 131, 148, 154(142), 155(237), 156(142, 237), 171(237) Montgomery, E. M., 9, 133, 196(156), 197(156), 285 Montgomery, R., 130, 170(139), 177 Moodie, A. M., 228 Moody, F. B., 101 Moog, L., 238 Moore, S., 328 Morgan, M. S., 193, 211(390) Morgan, P. W., 179 Morgan, W. T. J., 26, 157, 190(265), 191(265) Mori, T., 51, 55(30), 68(31), 69(30), 331, 332(60), 333, 334, 335, 336, 337, 338, 339, 340 Mbricz, M., 29, 132, 150(154), 154(154), 161(154) Morinaka, K., 274 Mosbach, E. H., 259 Moaingo, R., 163 Muhlhauser, 212 Muhlsohlegel, H., 36, 86 Mukherjee, S., 79, 145 Muller, A., 27, 29, 35, 94, 118, 132, 148, 150(154), 152(77, 79), 154(154, 238), 156(79), 161(79, 1541, 190(264), 191(264), 209(77), 213, 214(77, 79) Miiller, F. C. G., 108 Miiller, H., 101, 157, 184, 219 Munro, J., 218 Murakami, S., 289 Murray, G. E., 197 Murray, M. A., 163, 164(294) Murrill, P., 178 Musculus, O., 251
362
AUTHOR INDEX
Muskat, I. E., 116, 168, 169(308), 200, 228 Miither, A., 330,332(57), 334(57) Myrback, K., 262, 290
N N&dai, G., 110, 115(27), 116(27), 121(27), 165, 177, 180(27) Nagel, W., 31 Nagy, E., 163 Nakashima, T., 114, 115, 116(52, 531, 166 Naylor, G. L., 348 Neale, F. C., 275 Neill, J. M., 290 Neimann, W., 252, 254, 261(10) Nelson, E. K., 309, 310 Nelson, E. M., 296 Nelson, W. L., 340, 349 Nencki, M., 274 Ness, A. T., 27, 136, 151(170), 157(170), 158(170), 188, 189, 197(170), 203 (369) Neuberg, C., 252, 253, 254, 261(10), 274, 279, 290, 317, 323 Neumann, F., 119, 147(82), 150, 151(82), 152(82), 155(82) Nevell, T. P., 242 Newth, F. H., 76, 80, 81(164, 175), 83(164), 85(175), 162, 171 Nicholas, S. D., 171 Nicoll, W. D., 20 Nieman, C., 236 Niemann, R., 225 Nippe, W., 125 Nishida, Y., 323 Nishizawa, K., 344, 346, 347(109) Noelting, G., 347 Nord, F. F., 299 Nystrom, R. F., 83 0
Obermaier, L., 330, 333 O’Colla, P., 329, 334, 335, 336, 337, 347, 349 Octrooien Maatschappij, N. V., 304 Odell, A. D., 275 OdBn, S., 109,116(14,15), 135(14,15) Oertzen, K. von, 152, 214(252), 346
Ohle, H., 4, 21, 28, 117, 119, 120, 124, 128, 130, 131(73), 135, 136(73, 163), 139(73), 143, 144, 145(73), 146(192), 147, 148(192), 149, 151(73, 192, 193, 200, 231), 152(85, 114, 200), 153(16, 242), 154(85, 90, 138, 191, 231, 242), 155(85, 138, 140, 192, 200, 242), 158(73, 191, 192, 200, 242), 159(73, 114, 200), 167(163, 191), 170, 171, 175, 179, 205(140), 239(32), 317, 323, 324 Ohmori, T., 239 Ohta, K., 68 Okada, M., 238 Okafuji, 340 Oldham, J. W. H., 27, 109, 133, 135(20), 139, 146, 151, 152(20, 175, 217), 153(217), 155(20), 169(155), 170 (155), 172(175), 180, 191, 192, 193, 195, 196,197,201,210,338,345 Oldham, M. A., 146, 151(217), 152(217), 153(217) Olivarius, H. De F., 304 Ollendorff, G., 74, 85 Onuki, M., 289, 324 Oppenauer, R., 234, 236(24) Oppenheimer, C., 340 Oshima, G., 262, 318 Osman, E. M., 233 Ostrop, H., 108 Ott, E., 20, 31 Ottenstein, B., 51 Otterson, H., 294 Otto, R., 108, 111, 112, 116 O’Tuama, T., 348 Overend, W. G., 49, 50, 52, 54, 56, 62, 63, 67, 68, 69, 70(60, 112, 120, 127, 128), 72, 73, 74, 75, 79(61), 80, 81(175), 82, 83, 84(158), 85, 87(189a), 88, 89(61), 91(76, 128), 92(141), 93, 94(141), 95(141, 180), 96, 97(60, 112, 120, 128, 158), 98(128, 223), 99(112), 100, 101, 103, 136, 145, 146(169, 210), 151(169), 159, 171(169), 178, 184, 189, 193 (169), 195(356), 196(169), 200, 203, 204(382) Owen, L. N., 112, 140, 161, 173, 202, 203(411), 214, 215 a y , E., 340, 341(94)
363
AUTHOR INDEX
P Packham, M. A., 259 Pacsu, E., 6, 17, 70, 92, 99, 135, 155, 156, 160, 218 Panizzon, L., 152, 160(254) Papadakis, P. E., 18 Papadimitriou, I., 189 Papperstidn, S., 30 Parke, D. V., 274 Parker, L. F. J., 178 Parmanick, B. N., 115, 116(60), 121(60) Partridge, 5. M., 285 Patterson, A. M., 108 Patterson, B. M., 222 Patterson, J., 225 Patterson, T. S., 94, 116 Patterson, W. I., 314 Payen, A., 298,317 Payne, J. H., 304, 308, 312 Pazur, J. H., 289 Peacock, D. H., 180 Peat, S., 2, 7, 17, 146, 152(224), 153 (224), 160, 170, 171(311), 173(311), 174(311), 175(311), 176, 214(224), 217, 221, 224(23), 225, 226, 229(23), 236, 318, 319, 322, 323, 324, 325, 326, 327, 328 Percival, E. E., 125, 146, 151(125), 155(125), 166, 321, 332, 334, 336 (62), 342 Percival, E. G. V., 10, 13, 18, 21, 125, 146, 148(221), 151(125), 154(221), 155(125), 166, 170, 171, 200, 217, 218, 316, 318, 319, 320, 322, 323, 324, 325(9), 326, 332, 333, 334, 335, 336, 337, 338, 339, 340, 341, 342, 343, 344, 345, 346, 348, 349 Perkin, W. H., 201 Perlin, A. S., 242 Pesez, M., 65 Peterman, E. A., 232, 240 Peterson, W. H., 296 Petrow, V., 98 Pfleger, R., 30, 108, 116(7), 123, 124(7), 148, 154(240), 193(240), 197(7, 240), 2 12(240) Phillips, H., 167, 179(305), 180(305), 211(305), 212, 213(424), 214 Phillips, M., 294, 305(15)
Philpott, W. J. M., 70 Pierce, J. E., 242 Pigman, W. W., 30, 69, 72, 256, 262, 307 Piloty, O., 231, 233, 252, 257 Pirie, N. W., 55, 318, 322, 323 Pittman, V. P., 167, 179(305), 211(305), 212(305) Piwonka, R., 21 Plankenhorn, E., 153 Plant, M. M. T., 228 Plyler, E. K., 241 Polanyi, M., 168 Pollister, A., 54 Poplett, R., 123 Porter, C. R., 62, 135, 151(164), 160 Post, J., 108, 167(3) Pratt, 0. E., 297, 298(45) Pratt, J. W., 39, 196 Prins, D. A., 69, 70, 71, 75, 78, 83, 85(145), 89(162, 163), 90, 94(170), 132, 140, 157, 158(269), 162, 179 (289), 184, 200 Prinsen Geerligs, H. C., 298, 305 Pryde, J., 254, 255, 257, 258 Pucher, G. S., 294 Pummerer, R., 55, 56 Purdie, T., 19 Purves, C. B., 14, 20, 22, 23, 29, 30, 34, 35(118), 37, 118, 126, 132, 140, 141 (182), 193(182), 197, 280, 288, 290 Puskhs, T., 144, 152(204), 163
Q Quick, A. J., 232, 255, 256, 258, 274 Quintus Bosz, J. E., 298
R Raciborski, M., 296 Racker, E., 67 Rafique, C. M., 220, 221(17), 225(17) Raistrick, H., 220, 224(18) Ramsey, L. L., 314 Rands, R. D., 298, 314 Rankin, J. C., 235, 236 Rao, P. A., 131, 146(144), 147(144), 325 Rapoport, H., 121, 126(101) Raschig, K., 27, 180, 181, 186
364
AUTHOR INDEX
Raybin, H. W., 285, 290(27) Raymond, A. L., 35, 116, 124, 128, 135(133), 146(116), 151(72), 156 (116), 159(133), 161(116), 178, 184, 186, 193(133), 195, 197(361) Raaorenov, B. A., 113 Reber, F., 157 Reckhaus, M., 10 Reeves, R. E., 13, 14(41), 146, 150(225), 158(219, 225), 159(219, 225), 161 (225) Rehorst, K., 234, 235 Reichard, P., 50, 52 Reichstein, T., 26, 46, 69, 75, 77, 78, 83(169), 89, 90, 91, 100, 101(126), 124, 132, 135, 140(151, 152, 153), 146, 151, 153(150), 157, 158(226, 270, 271), 160(152), 162, 173(288), 179(152, 226), 180(152), 184, 189, 190(264, 265), 191(264, 265), 196 (271), 205(113), 234,235,236(24) Reiff, G., 41, 239 Reischel, W., 154 RemBnyi, M., 39 Renfrew, A. G., 121 Restelli de Labriola, E., 36 Reverdin, F., 116 Reynolds, D. D., 120, 126, 127(95), 132 (127) Reynolds, T. M., 119, 154(83), 160(84), 178(84) Ricard, P., 344, 347(107), 348 Rice, F. A. H., 334 Richards, G. N., 76, 81, 83(164) Richtmyer, N. K., 9, 16, 35, 39, 40, 133, 140, 147(180), 160(180), 184, 196, 197(156), 213(180), 281, 282, 285, 289 Riedel, H., 125 Riegel, E. R., 292 Rigby, G. W., 114, 115(48), 139(48) Rigby, W., 39 Riiber, C. N., 94 Ris, H., 64 Rist, C. E., 33, 43, 44, 190, 210, 232, 243, 246(14), 248(14) Ritchie, G. G., 18 Rivers, T. M., 55 Roberts, E. J., 298, 299(67), 310(65), 314
Robertson, G. J., 3, 29, 132, 133, 146, 147, 152(230), 153(145), 159(214), 161(214, 223), 169(155), 170(155), 178(214), 221 Robertson, J., 94 Robinson, D., 274 Robinson, R., 166 Rodionow, W., 180, 211(341), 212(341) Rogers, D., 308 Rooney, C. S., 307 Roos, A., 112 Rose, I. A., 15 Rose, R. C., 331 Rosenfeld, D. A., 184 Rosenkrantz, H., 296, 308(39) Ross, A. G., 340, 344, 345, 346, 348, 349 Ross, M. H., 64 Ross, W. C. J., 188 Rossenbeck, H., 61 Rothstein, E., 127 Rowen, J. W., 241 Rubin, L. J., 188 Ruff, O.,74, 85 Ruhkopf, H., 151, 152(247), 156(247), 158(247) Rumpf, P., 63 Rundell, J. J., 289 Rundle, R. E., 230 Russell-Wells, B., 330, 332, 334, 336, 348 Rutenberg, A,, 287 Rutherford, J. K., 27, 109, 135(20), 139, 151(20, 175), 152(20, 175), 155(20), 172(175), 191, 192, 193, 195, 196, 197, 201, 210 Rutkowski, R., 38 Rutz, G., 73 Rydholm, S., 30 Ryman, B. E., 253, 274 S
Sable, H. Z., 49 Sakurada, I., 25, 35(94), 114, 115, 116(52, 53), 166 Salant, W., 274 Saluste, E., 50 Sammons, H. G., 255, 256 Sands, L., 232 S a d , S. M., 115, 116, 121(60)
AUTHOR INDEX
Santiago, E., 243 Sato, T., 235 Satoh, K., 178, 179(332) Sattler, L., 66, 305, 307, 311(96, 105) Scattergood, A., 74, 146, 244 Schaffer, R., 19 Scheuing, G., 63 Schick, E., 148, 204(236) Schiff, H., 62, 63, 64, 97 Schiller, R., 111 Schimper, F.-W., 349 Schindler, O., 52 Schinle, R., 36, 86 Schlags, R., 20 Schlegl, K., 139 Schlicht, R. C., 307 Schmid, F., 258, 259 Schmid, H., 164 Schmid, M. D., 86, 87 Schmid, W., 251 Schmidt, C., 330 Schmidt, E., 73 Schmidt, H., 27 Schmidt, 0. T., 184, 219, 234, 235, 241 Schmiedeberg, J. E. O., 344 Schmiedeberg, O., 231, 251, 257 Schneider, W. C., 54, 59, 65(45) Scholz, H., 234, 235 Schotte, H., 46, 47, 69(3, 61, 70, 72, 73(117), 86(3), 91(6), 92(118), 101 (118) Schotten, C., 113 Schramek, W., 32 Schreiber, K. C., 7, 141, 142 Schroeder,E.F., 116,151(72), 184,186 Schuetz, R. D., 306 Schiiller, J., 257 Schuller, W. H., 147, 211(233) Schulta, C. A., 28 Schumacher, J. N., 311 Schwarte, G. L., 134, 137(159) Schware, K., 65 Schweigert, I3. S., 15 Schweizer, R., 35, 36(146), 131 Schwenk, E., 274 Schwyapr, R., 148, 204(236) Sebor, J., 330, 332(56), 333, 334(66) Seebeck, E., 189 Seegmiller, J. E., 38 Seibert, F. B., 55
365
Sekera, V. C., 120, 212(93) Seligman, A. M., 135, 245 Sell, H. M., 236, 237(34) Sera, Y., 262, 274 Serchi, G., 234 Sessler, P., 237, 238 Sevag, M. G., 55, 80 Shafiaadeh, A. F., 56, 69(60), 70(60, 127), 72, 73, 96, 97(60), 100 Shankman, S., 297 Sheffield, E. L., 5, 27(13), 171, 208 Shelswell, J., 274 Sherwin, C. P., 275 Sherwood, 6. F., 279, 283 Shockley, W. M., 130, 134(137), 197 (137) Shorey, E. C., 298 Shorr, E., 274 Shorygin, P. P., 35 Shriner, R. L., 63 Shutt, G. R., 211 Sibatani, A., 64 Siegcl, S., 121 Simpson, S. A., 274 Singer, R., 161 Sinsheimer, R. L., 52 Sjostrom, L., 275 Slotta, K. H., 113, 115(27) Smadel, J. E., 55 Smeykal, K., 178 Smith, A. E. W., 274 Smith, €3. A., 294, 306(18), 314 Smith, E. E. B., 262, 263 Smith, F., 44, 62, 113, 131, 145, 146(144), 147(144), 148(143), 154(143), 161, 171, 172(206), 219, 220, 221(17), 224, 225(15, 17), 231, 234, 235, 244(25), 319,325, 329, 337,342 Smith, J. D., 49 Smith, J. N., 246, 254, 274, 275 Smith, L. I., 11 Smith, P. N., 214 Smith, R. G., 295 Smoleiiski, K., 247, 248 Smollens, J., 55, 80(51) Snell, E. E., 297, 308 Soff, K., 322 Sohst, O., 233 Sokolova, N. M., 114, 115(48), 166(48) Soltero-Diaa, H., 243
366
AUTHOR INDEX
Soltzberg, S., 5, 27(13), 208 Somerville, J. C., 316, 318, 323, 324, 325(9), 326(3), 337 Sorkin, E., 77, 132, 153(150), 189 Soutar, T. H., 319 Souther, B. L., 121 Sowden, J. C., 19, 27, 46, 47, 48, 73, 74, 75, 120, 123, 146, 166(106), 175(218), 197(106), 248 Spencer, B., 274 Spencker, K., 120, 149(90), 154(90) Spiegelberg, H., 235 Spits, D., 240, 241(48), 256, 257 Spring, F. S., 52 Sprock, G., 125 Spurlin, H. M., 23 Srikantan, B. S., 299 Srinivasan, N., 310 StaceY, M.9 33, 52, 54, 55, 56, 57, 62, 63, 64, 67, 68, 69(60), 70(60, 1% 120, 127, 128)s 72, 73, 74, 75(158), 79(61), 81, 84, 85, 87, 88, 89(61), 91, 92(141), 93, 94(141), 95(141), 96 (1411, 97(60, 112, 120, 128, 1581, 98(128, 2231, 99(112), 100, 101, 103, 113, 136, 144, 145, '46(169, 2lO), 151(169), 152, 158(253), 160(253), 171(169), 172(206), 176, 184, 193 (169), 195(356), 196(169), 200, 220, 221, 224,_226, 231, 232, 233(6), 238, 245, 246 Stadler, H., 295 Stanek, J., 69, 70(120), 97(120) Stanford, E. C. C., 330, 348 Stary, B., 263 Staub, M., 21 Stauffer, H., 29, 126, 139(128), 141, 154 (126) Stedman, E., 61 Stedman, Ellen, 61 Steel, T., 295 Stein, W., 35, 108 Stenzel, H., 29, 124, 125(117), 136(117), 196(117) Stenzel, W., 258 Stewart, L. C., 40 Stewart, W. T., 349 Stiff, H. A., 251 Stiles, H. R., 296 Stiller, E. T., 125, 145, 155(123)
Stocker, E., 139 Stokes, J. L., 298 Storey, I. D. E., 258, 260, 263 Story, L. F., 50 Stowell, K. E., 61 Strauss, F., 161 Streight, H. R. L., 69, 225, 336 Stricker, F., 38 Strocchi, P. M., 20 Stryk, F. von, 25, 161 Stubbs, A. L., 274 Stumpf, P. K., 65 Sturgeon, B., 98 Suckfiill, F., 156 Sugg, J. Y., 283 Sugihara, J. M., 21 Sullivan, W. R., 144, 146(194), 152(194) Sumner, J. B., 262 Sumner, J. M., 290 Sundman, J., 16 Sundvik, E., 257 Sutherland, E. S., 275 Sutter, M., 234, 235 Sfivern, c., 115 Synge, R. L. M., 145 Syniewski, W., 248 Ssabo, A. L., 168
T Tabern, D.L., 116,117(70), 135(70) Tadokoro, T., 348 Tagliani, G., 114, 115(50, 54) Takao, K., 274 Takao, Y., 319, 334 Takasugi~ 348 Takei, S., 311, 312 Talalay, P., 246 Tamm, C., 69, 90, 101(126), 157, 158 (270), 168 Tamura, S., 274 Tanabe, T.9 298 Tanghe, L. J., 87, 197 Tanret,W., 214 Tappe, G., 278, 279, 289 Thrnoky, A. L., 110 Tarr, H. L. A., 290 Tasker, C. W., 30, 118, 140, 141(182), 193(182), 197(80)
3 67
AUTHOR INDEX
Tatlow, C. E. M., 33, 152, 158(253), 160 Tatlow, J. C., 33, 152, 158(253), 160 Taube, C., 135 Taylor, C. S., 298, 309(53) Taylor, E. W., 42, 241, 242(53) Taylor, F. M. H., 167,211(305),212(305) Teece, E. G., 3, 54, 55(48), 57(48), 64(48), 68, 70(112), 97(112), 99(112) Tempus, F., 44 Terry, M., 108, 167(3) Tessmar, K., 21 Thannhauser, S. J., 51 Thiel, H., 144, 146(192), 148(192), 151 (192), 155(192), 158(192), 324 Thiel, R., 31, 32(128) Thierfelder, H., 245, 275 Thiirkauf, M., 83 Thomas, H. A., 69 Thomas, L. M., 38 Thompson, A,, 47 Thomson, T. G. H., 326 Thorpe, W. V., 253, 260, 274, 275 Tiessen, D. V., 21, 22(67) Tilden, E. B., 39, 40 Timell, T., 30, 197 Tipson, R. S., 24, 51, 62(26), 69, 101, 111, 113, 123, 124, 127, 136, 140, 142, 144(111), 146(40, 107), 161, 166, 178, 179(111), 184, 188, 189, 190, 192, 195, 196, 201, 205, 206(364), 209(364), 210(131), 214(364), 229 Tobin, L. C., 309 Todd, A. R., 50,52,79,132, 145, 186,246 Tollens, B., 65, 100, 233, 294, 318, 330, 332(57), 334(57), 340 Tomecko, C. G., 24 Tomoda, Y., 348 Torup, S., 344 Toussaint, G., 124 Traquair, J., 36 Traube, W., 21 Trauth, O., 178, 179(333) Trenner, N. R., 43, 243, 246 Trippett, S.,79 Trister, S. M., 218 Trogus, C., 21, 32 Tseng, C. K., 316 TSOU, K. C., 245 Tsuchiya, Y., 331, 332(60), 333, 334, 335(63), 336, 337(76)
Tsunoo, S., 274 Turchini, J., 66 Turer, J., 309 Turley, H. G., 167, 180(305), 211(305), 212(305), 214
U Ullmann, F., 110, 111, 115, 116, 121(27, 60, 68), 165, 177, 180(27) Ulrich, P., 90, 162, 164(291), 165(291) Umezawa, S., 274 Underkoflcr, L. A., 40 Unruh, C. C., 42, 241, 242
V Valatin, T., 224 van Breda de Haan, J., 298 van der Haar, A. W., 66
Van Hook, A., 292 van Tamelen, E. E., 6 Van Wagtendonk, J., 296, 308(38) Vargha, L. von, 3, 25, 28, 39,117,118(77), 143, 144, 147, 149(191, 231), 151 (231), 152(77, 204). 154(191, 231), 158(191), 159(189), 163, 167(191), 170, 175,209(77),214(77), 238 Vasseur, E., 317 Veitsman, A. E., 35 Vellus, L., 65 Venning, E. M., 275 Ventre, E. K., 309 Verner, G., 29, 132, 150(164), 154(151), 161(154) Vickery, H. B., 294 Vischer, E., 49, 69, 90, 124, 205(113) Vock, M., 27, 109, 156(18), 168(18), 212(18) Vogel, H., 33 Vogl, K., 130, 149(138), 153(138), 154 (138), 155(138) Volkin, E., 52 Volwiler, E. H., 116, 117(70), 135(70) voss, 94
w.,
W Wadman, W. H., 346 Waine, A. C., 160
368
AUTHOR INDEX
Waisbrot, S. W., 87, 88 Walawalkar, D. G., 299 Walder, W. O., 221, 329 Waldron, D. M., 66 Walker, P. G., 262 Wallace, E. G., 306 Walter, H., 115 Walti, A., 21 Walton, C. F., Jr., 296 Wang, T. P., 50 Watanabe, T., 236, 237, 239(32) Watters, A. J., 219 Wattiez, N., 290 Weakley, F. B., 285 Webb, J. I., 69 Webb, M., 49, 50 Weber-Molster, C. C., 219 Wehrli, W., 116, 119, 165 Weidenhagen, R., 280, 282, 283, 289, 290 Weidlein, E. R., 127, 210(131) Weinmann, F., 232 Weisblat, D. I., 88 Weissberger, A,, 17 Weltaien, W., 161 Wenner, P., 111 Went, F. A. F. C., 297 Wernicke, E., 184 Weygand, F., 10, 85, 178, 179 Whistler, R. L., 17, 220, 225(16), 349 White, E. V., 197 White, J. W., Jr., 290 White, K., 260, 274 White, W. C., 286 Whitehead, W., 146, 159(214), 161(214), 178(214) Widstrom, G., 61 Wieland, H., 63 Wiggins, L. F., 7, 27, 54, 55(48), 57(48), 64(48), 68, 69, 70(112), 74, 75(158), 76, 80, 81, 82, 83, 84(158), 85(175), 92(141), 93(141, 179), 94(141), 95 (141), 96(141), 97(112,158), 99(112), 100(141), 130, 133, 136, 144, 145, 146, 151(169, 205), 152(224), 153 (224), 162, 170(139, 224), 171, 172 (206), 173, 176(205), 177, 189, 193 (169), 196(169), 200, 204(378), 208, 211(414), 214(224), 222, 295, 297, 298(45), 300, 314
Wilcke, H., 130, 149(140), 155(140), 170(140), 205(140) Wild, G. M., 290 Wilhelms, A., 27, 213 Williams, E. M. L., 147 Williams, J. H., 297, 298(45) Williams, R. J., 308 Williams, R. T., 232, 246, 253, 254, 255, 256, 257, 258, 274, 275 Williamson, S., 27, 29, 111, 124(34), 146, 154(34), 167(212), 186(34), 197(34), 324 Wilson, C. E., 8 Wilson, P. I., 224 Winkler, S., 181 Winstein, S., 7, 8, 28 Winter, H., 38, 298 Wohl, A., 5, 19(14) Wolf, A., 125, 138(121) Wolf, D. E., 163 Wolf, J. T., 275 Wolfe, J. K., 124, 189, 197(376) Wolff, A., 87 Wolff, H., 108 Wolff, J,., 87 Wolff, W., 235, 248 Wolfrom, M. L., 17, 21, 47, 87, 88, 101, 123, 156, 166(106), 189, 197(106), 293, 294, 296(21), 297, 299, 304, 305, 306, 307, 308, 315, 321, 322 Wolkow, A., 108 Wolz, H., 85, 179 Wood, D. J. C., 27, 82, 133, 189, 208, 211(414) Wood, P. B., 260, 275 Woodhead, A. E., 114, 115(50) Woodhouse, D. L., 56 Woolf, L. I., 127 Woolley, D. W., 297 Woolley, J. M., 226 Woolvin, C. S., 69 Wulzen, R., 296, 297, 308(38) Wyatt, G. R., 49 Wylam, C. B., 289
Y Yackel, E. C., 42, 232, 241 Yanagawa, T., 318, 323, 336 Yeakel, E. H., 35 Yoder, P. A., 298
AUTHOR INDEX
Yoshimura, K., 348 Young, B., 290 Young, E. G . , 334 Young, F. G., Jr., 140 Young, L., 274 Yovanovitch, O., 21, 22(67) Yusem, M., 138
2 Zaheer, S. H., 125, 138(121) Zamenhof, S., 49
369
Zechmeister, L., 17 Zeisser, H., 234 Zemplh, G., 70, 99, 160, 224, 280, 289 Zerban, F. W., 66, 293, 296, 297, 298, 299, 300, 305, 307, 311(34, 96, 106) Zervas, L., 74, 189, 237, 238 Zief, M., 5, 27(13), 184, 212 Zill, L. P., 14, 15(44) Zophy, W. H., 88 Zussman, J., 186 Zweig, G., 17
Subject Index Adrenaline, 258 Agar, 316, 317-328 acetolysis, 322, 323 Acanthopeltis japonica, 317, 318, 322 Acetal formation, correlation with cucomposition, 317-323 prammonium complexing, 14 ester sulfate of, 316, 317, 319, 323 Japanese, 317 Acetals, cyclic, 14 Japanese method of manufacture, 317 Acetic anhydride, in desulfonyloxylation, 189 methanolysis, 321 Acetobacter suboxydans, 39, 40, 41 methylated, 316, 318, 319, 323, 324, action on a-deoxyalditols, 40 325, 326, 328 action on L-fucitol, 40 methylated, acetolysis of, 325 oxidation of cyclitols by, 41 structure, 323-328 oxidattion of deoxycyclitols by, 41 sulfur content. See table for sulfur Acelobacter xylinum, 39 contents of agar from various Acetonation, 147 agarophytes on page 332. Acetone, 3-C-phenyl-dihydroxy-, 11 Agarobiose, 320 Acetylation, 147, 149, 158, 159, 210 methylated, 320 preferential, 33 phenylosazone, 320 Acetylbenzoyl, 12 structure, 326 Acidity, of sugars, 20 -, hexa-0-benzoyl-, 320 Acids, 2-keto-, synthesis, 44 -, hexa-0-methyl-, dimethyl acetal, 326 Aconitase, enzyme system, 299 Agarobioside, methyl penta-0-methyl-, Aconitic acid, calcium-magnesium salt, 326 303 Agarophyte, the term, 317 from cane distillery slop, 310 Albumins, in cane juice, 297 in cane juice, 298, 299, 303, 314 Alcohols, Gnitro-, 73 in molasses, 309, 314 Aldobiouronic acid, of cherry gum, 226 trans-Aconitic acid, dicalcium magneof damson gum, 226 sium salt, hexahydrate, 309 “Aldodesonic” acids, acetylated, 88 Acrolein, 204 Aldohexofuranoses, 5-O-sulfonyl-, 173 diethyl acetal, 204 Aldohexoses, monoanhydro-mono-0-isoAcyl-oxygen fission, 110, 164, 166, 169 propylidene-mono-0-tsyl-, deacetoAdenine, 9-(2,3-di-O-acetyl-5-O-tosyl-pnation, 144 ~-ribosyl)-N-tosyl-, 182 Aldonic acids, acetylated, 88 -, deoxy-methylthiopentosyl-, 178 Aldopentose dialkyl thioacetals, 5-0-, 9-(2,3-di-0-tosyl-p-n-ribofuranosyl)sulfonyl-, 129 N-tosyl-, 199 Aldoses, formation, 43 Adenosine. See also Adenine, 9-p-~- -, 2-0-methyl-, 71 ribofuranosyl-. -, 1-0-sulfonyl-, 142 -, 2,3-0-isopropylidene-5-O-tosyl-,186 Aldosides, alkyl 2,3-anhydro-, 75 -, N-tosyl-2,3-di-O-tosyl-5-0-trityl-,144 Ndosyl bromide, poly-0-acetyl-, 68, 70 5,3’-cyclo-Adenosine iodide, 2,3-O-isopro- Algae, 316, 330, 344, 348, 349, 350 pylidene-, 186 Nginic acid, 316, 349 370 A
SUBJECT INDEX
estimation of, in seaweeds, 349 methylated, 349 Alkali complexes, with amylose, 21 with cellulose, 20 with glycogen, 21 with inulin, 21 with starch, 21 with sugars, 18 Alkali-metal halides, action on sulfonic esters, 180-212 Alkali-metal mercaptides, action on sulfonic esters, 178-179 Alkali-metal sulfides, action on sulfonic esters, 179 Alkaline hydrolysis, of a secondary sulfonyl group, without Walden inversion. See table on page 168. Alkaline reagents, action on sulfonic esters, 165-180 Alkalis, alcoholic, action on sulfonic esters, 166-175 Alkyl chloride, formation, in sulfonylation, 121, 124 Alkylation, in quaternary ammonium bases, 22 Alkyl-oxygen fission, 110, 122, 164, 180 Allitol, z-deoxy-~-, 101 -, 2,6-dideoxy-~-,101 -, 2,4 :3,5-di-O-methylene-1,6-di-Otosyl-, 187 D-Allomethylitol, 2-deoxy-. See Allitol, 2,6dideoxy-~-. D-dlomethylose. See D-Allose, 6-deoxy-. -, 2-deoxy-. See D-Allose, 2,6-dideoxy-. a-D-Allopyranoside, methyl 2-deoxy-3-0methyl-6-0-tosyl-, 182 D-Allose, 173, 174 4,6-di-O-acetyl-2,3-dideoxy-, 89 -, 2-deoxy-, 48 3-methyl ether, 77 -, 6-deoxy-, 89 -, 2,6-dideoxy-, 66, 69, 89, 90 3-methyl ether. See D-ribo-Hexose, 2,6-dideoxy-3-0-methyl-. reduction of, 101 D-Alloside, ethyl 4,6-di-O-acetyl-2,3-dideOXY-, 89 2,3-didehydro derivative, 89 -, ethyl 2,3-dideoxy-, 89 --]
37 1
-, methyl 4-0-acetyl-2,3-anhydro-6-0tosyl-a-, 182
-, methyl 3,4-di-O-acetyl-2-deoxy-6-0tosyl-a-, 90, 182 methyl 3,4-di-O-acety1-2,6-dideoxy-a-, 90 6-iodo derivative, 90 -, methyl 2,3-anhydro-4,6-O-benaylidene-or-, 75, 80, 89, 178 -, methyl 3,4anhydro-2,6-di-O-methyli3-, 153 -, methyl 2,3-anhydro-4,6-di-O-tosyl-or-, 165 -, methyl 2,3-anhydr0-5,6-di-O-tosyl-p-, 205 -, methyl 4,6-0-benzylidene-2,3-didehydro-2,3-dideoxy-aY-,94 -, methyl 4,6-O-beneylidene-3-deoxy-20-methyl-or-] 81 -, methyl 4,6-O-benzylidene-2,3-dideoxy-ff-] 94 -, methyl 2-deoxy-a-, 75, 76, 89 4,G-0-benaylidene acetal, 83 3-methyl ether, 77 4,6-ditosylate, 83 -, methyl 2,6-dideoxy-a-, 165 $-tosylate, 162, 165 -, methyl 6-deoxy-2,3-O-isopropylidene5-O-t0syl-, 162 -, methyl 2,6-dideoxy-3-O-methyl-40tosyl-a-, 162 D-Ahlose. See D-ribo-Hexulose. Allylmagnesium bromide, 83 n-Altromethylose. See D-Altrose, 6-deoxy-. or-D-Altropyranoside, methyl 2-0-methyl6-0-t0syl-, 182 D-Altrose, 1,6-anhydro-3,4O-isopropylidene-2-0-tosyl-p-, 162 -, 2-deoxy-. See n-Allose, Zdeoxy-. -, 6-deoxy-, 157 D-Altroside, methyl 3,4di-O-acetyl-2-0rnethyl-6-0-tosyl-a-, 140, 182 -, methyl 2,3,4tri-O-acetyl-6-0-tosyl-or-, 182 -, methyl 3-amino-3-deoxy-O-, 176 -, methyl 2,3,4-tri-O-benaoyl-6-O-tosyla-,182 -, methyl 4,6-O-benaylidene-3-deoxy-c~-, 78, 83
-,
372
SUBJECT INDEX
3-hydrazino derivative, 178 water-soluble, in cane juice, 299, 303 3-methylthio derivative, 78 “Antistiffness factor,” in cane juice, 296 2-tosylate1 94 in cane molasses, 308 -, methyl 4,6-0-benzylidene-2-deoxy-2- Apiose, 52 ethylthio-a-, 76 Apocupreine, 0, y-0-isopropylidene-j3, y-, methyl 4,6-0-benzylidene-2-deoxy-2dihydroxy-n-propyl-, 113 hydraeino-a-, 178 L-Arabinal, 3,4-di-O-acetyl-, 89 -, methyl 4,6-0-benzylidene-2-deoxy-2- Arabinose, L-, dibenzyl thioacetal, 18 methylthio-a-, 75 L-, diethyl thioacetal, 18 3-methyl ether, 77 I.-, N-j3-naphthyhulfonylhydrasone, -, methyl 4,6-O-beneylidene-3-0-methyl108 a-,164 -, tetra-0-acetyl-a-, 70 2-tosylate, 164 -, 5-O-benzoyl-~-, diethyl thioacetal, 35 -, methyl 2-bromo-2-deoxy-,~-, 80 -, 5-deoxy-1.-, dibenzamide, 36 -, methyl Zchloro-2-deoxy-a-, 81 -, di-0-isopropylidene-aldehydo-D-, 222 -, methyl 6-deoxy-3-0-rnethyl-2,4di-O- -, 1,2-0-isopropylidene-5-0-tosyl-~-, tosyl-a-, 162 147, 162, 182 -, methyl 4,6-O-hexahydrobenzylidene3-methyl ether, 162 3-0-methyl-4-0-tosyl-~-, 162 -, 2,3,5-tri-0-methyl-c1 226 -, methyl 3-0-methyl-2,4,6-tri-O-tosyl--, 5-O-toSyl-L-, 156 a-, 194 l,2,3-triacetate, 182 Amadori rearrangement, 10, 12, 60, 98 diethyl thioaoetal, 156 Amines, action on sulfonic esters, 177-178 Arabinoside, ethyl 3,40-isopropylideneAmino acids, glucogenic, 258 2-0-mesyl-S-~-, 145, 199 in cane juice, 297, 298, 302 -, methyl a+, 164 in molasses, 308, 313 -, methyl prc, 87 Ammonia, action on sulfonic esters, 1752-mesylate, 87 177 -, methyl 3,4-di-O-acetyl-2-O-mesyl-pAmmonium molybdate, augmentation of D-, 199 optical rotation of polyols, 16 -, methyl 2-bromo-2-deoxy-&~-, 81, 82, Amylopectin, of corn starch, 242 93 oxidation, 42 -, methyl %ch~oro-2-deoxy-fi-~-,82 structure, 42 -, methyl 3,4-0-ethylidene-~-~-, 136 Amylose, of corn starch, 242 2-tosylate, 136 oxidation, 42 -, methyl 3,4-0-isopropylidene-~-~-, 87 Amylosuorase, 287 Zmesylate, 87, 144 Anhydride formation, 7-10 2-tosylate, 87 Anhydro rings, 210 -, methyl 3,4-O-isopropylidene-2-0effect on stability of primary sulmesyl-a+-, 199 fonyloxy group, 189 8-anomer, 145, 199 formation, 87, 163, 170, 176, 319 -, methyl 3,4O-isopropylidene-2-0scission, 174-175 tOSyl-P-D-, 144, 199 Anhydro sugars, 7 -, methyl 2-0-tOSyl-j3-D-, 159 Aniline, effect in vivo, 254 3,4-bis-p-nitrobenzoate1159 -, D-ribopyranosyl-, 235 -, methyl 2-0-tosyl-a-~-, 164 complex with sodium sulfate, 235 j3-anomer, 87 -, n-ribopyranosy1-3,4-dimethyl-,comS-anomer, 3,4O-benaylidene acetal, plex with sodium sulfate, 235 146 Anion exchangers, 15 -, methyl B-O-tosyl-~-, 147, 156 Anthocyanins, in molasses, 311, 314 a-anomer, 2,3-diacetate, 182
SUBJECT INDEX
Arabinosyl bromide, tri-0-acetyl-, 70 D-habitol, in molasses, 306 -, 2,3,4,5-tetra-O-acetyI-l-deoxy-lnitro-, 74 -, 3,5-0-beneylidene-l-deoxy-l-nitro-, 74 Arabogalactan, from larch wood, 197 u-habonic acid, 44 8-D-Arabopyranoside, methyl 2-0-mesyl-, 199 Arsenolysis, 103, 105 Ascophylluni nodosum, 340 L-Ascorbic acid, 232, 243 L(Zeuo)-Asparagine, 297, 302 Aspergillus oryzae, 279, 281
B
373
Benzylidenation, 151 Bertrand’s Rule, 39 Boric acid, complex formation with glycols, 14, 15 Borneol, 254 conjugation of, 258, 259 p-toluenesulfonate, 167 Bredereck reaction, 319 2-Bromo-2-deoxysugars, 72 “Browning’, reaction, 306, 307, 309, 311, 314 Buffers, boric-borate, 15 Butadiene, 201 Butane, cis-2,3-epoxy-, 8 -, n-trans-2,3-epoxy-, 8 2,3-Butanediol, D - ~ ~ R o - ,8 diacetate, 8 chlorohydrin, 8 -, DL-, 8 2-Butanol, D(-),L( +)-threo-3-amino-, 176 -, ~~-threo-3-bromo-, 8 7-Butyrolactone, d ( - )-a-hydroxy-&b-dimethyl-, p-toluenlsulfonate. See u (?)-glycero-Tetronic acid, 3-deoxy3,3-dimethyl-2-0-tosyl-, lJ4-lactone.
Bacillus mesentericus, 295 Bacillus subtilis, 52 Bacteria, in molasses, 314 Bagasse, 292 Barium methoxide, 157, 161 “Bauer “ oil, 310 Benzene, 2,4dinitrofluoro-, 85 Benzenesulfmic acid, 10 Beneenesulfonic acid, p-bromo-, ethyl ester, 180 I ; Beneenesulfonic anhydride, 139 Beneimidazole, 1-(3,4di-0-acetyl-2deCamphene, from borneol, 126, 167 oxy-~-ribosyl)-5,6dimethyl-, 99 Cane distillery slop, 309 -, 1- (2-deoxy-~-glucopyranosyl)-5,6-di-Cane final molasses, composition, 303methyl-, 99 314 3,4,6-triacetateJ 99 constituents, 313-314 picrate, 99 inorganic components, 312, 314 -, 1-(2-deoxy-~-ribopyranosyl)-5,6-di- Cane juice, acetylated solids of lyophilmethyl-, 99 ized normal, 293 -, 6,6-dimethyl-, silver, 98 bacterial carbohydrates in, 295 Beneimidazole glycosides, 98 composition, 292-303 Benzoic acid, 3,5-diamino-, 65 constituents, 302-303 empirical analysis, 292 Benzoyl group, migration of, 36 Benzoylation, of hydroxyl groups, 158 Florida crusher, 292 dimolar, 159 inorganic components, 301, 303 selective, 35 non-nitrogenous organic acids of, 298, unimolar, 159 314 Beneylation, partial, of cellulose, 24 normal carbohydrates of, 292 “screened” crusher, 292 of methyl a-D-glucopyranoside, 24 the term, 291 of starch, 24 Cane-molasses yeastfermentation resiof sucrose, 24 Bis-(a-beneylethyl) sulfide, 179 due. See Cane distillery slop.
374
SUBJECT INDEX
Carbazole test, 64 mesylation, 123 Carbinol, diethyl-0-tosyl-, 206 6-nitrate, 42 -, dimethyl-0-tosyl-, 206 oxidation with nitrogen dioxide, 42 -, di-n-propyl-0-tosyl-, 206 partially acetylated, tosylation and Carbohydrase, for hydrolysis of Chondrus quaternization, 120 ocellatus mucilage, 339, 340 partially ethylated, 132, 197 Carbohydrate sulfate esters, 316 partially hydroxyethylated, 197 Carbon disulfide, reaction with polyols, partially propylated, 197 31 preferential nitration, 241 Carboxylic acids, formation of, 41 selective oxidation, 241, 242 Cardiac glycosides, 89-91 tosylation, 113, 114, 115, 116, 122, 123, Carrageen, mucilage. See Carrageenin. 126, 139, 213 Carrageenin, 316, 317, 330-340 xanthation, 32 composition, 333-336 -, 0-acetyl- (acetone-soluble), 34, 197 desulfated and acetylated, 336 positions of free hydroxyl groups, 35 desulfated and methylated, 336, 337, tosylation, 34, 126, 132 338 tritylation, 35 ester sulfate of, 323, 335, 336 with disulfide cross-links, 179 2-ketogluconic acid in, 334, 335 -, 0-acetyl-0-tosyl-, 179 methylpentose in, 334 -, 0-allyl-, 24 pentose in, 334 -, 0-benzyl-, 23 -, 0-carboxymethyl-, 23, 30 portion resistant to hydrolysis, 339 structure, 336-339 -, 0-ethyl-, 23, 29 Catalyst, palladium-impregnated calcium -, 0-hydroxyethyl-, 30 carbonate, 242 tosylated, 118, 213 platinum-carbon, in oxidation, 43, 243 -, 0-methyl-, 21-23 -, nitro-, 197 Catalysts, noble-metal, 242 -, di-0-tosyl-, 123 Cellobiose, tosylation, 126 -, 0-tosyloxyethyl-, reaction with di-, octa-0-acetyl-, 348 -, 2-deoxy-, 69 sodium sulfide, 179 hexaacetate, 69 Celluronic acid, incompletely oxidized, 41 @-Cellobioside, methyl 2,3,4,2’,3’-penta- Ceramium Hypnaeoides, 317, 322 O-acetyl-6,6’-dideoxy-6, 6’-diiodo-, Ceryl alcohol, from cane juice, 300 Cherry gum, aldobiouronic acid, 226 181 -, methyl 2,3,4,2’,3‘-penta-O-acetyl-6,6’- D-Chinovose, Zdeoxy-3-O-methyl-, 69 di-0-mesyl-, 184 Chloral hydrate, 251 -, methyl 2,3,4,2’,3’-penta-O-acetyl-6,6’- Chlorophyceae, 316 di-0-tosyl-, 184 Chlorophyll a, in cane juice, 299, 303 in molasses, 311, 314 -, methyl dianhydro-, 171 Chloroplatinic acid, in glycal prepara-, methyl 6,6’-di-O-mesyl-, 25 tions, 70 -, methyl 6,6‘-di-O-tosyl-, 25 Cholesterol, tosylate, 213 or,fl-Cellobiosides, methyl, 91 Cellulose, 197, 316 Chondrosamine, 172 Chondrus aqueous extracts, analyses of, algal, 348 332 degraded, tosylation, 108 derivatives, “aminated,” 165, 166 ash constituents of, 331 composition, 332 effect of alkalis, 20 physical properties, 331 heterogeneous sulfonylation, 134 Chondrus canaliculatus, 330 heterogeneous tosylation, 130 in Laminariae, 348 Chondrus wispus, 330, 331, 332, 333, 334
SUBJECT INDEX
375
Debenzoylation, 159, 161 cold-water extract, 330, 331 selective, 36 hot-water extract, 331 Chondrus ocellatus, 330, 331, 332, 333, Debenaylidenation, 78, 90, 144-147, 156 Decarboxylation, 44 335, 336, 338, 339, 340 Chondrus ocellatus mucilage, enzymic hy- Decyclohcxylidenation, 146 Deethylidenation, 146 drolysis, 339, 340 Defecation process, in sucrose production, preparation of barium salt, 333 304, 312 Chromatography, 17, 21, 52, 82, 85, 132, 140, 285, 293, 294, 297, 298, 300, 305, Defecation solutions, alkaline, 300, 306 306, 307, 308, 309, 311, 312, 339, 341, Dehydrobromination, 8 Dehydrochlorination, 8 346 Dchydrohalogenation, 7, 8 Citric acid, in Louisiana cane juice, 314 Delphinidine, mono-0-methyl-, 299 Coenzymes, 96 Demercaptalation, 87, 156 Colothrix scopulorum, 350 Demethylation, with acetic anhydrideCopper xanthate, 31 hydrogen bromide, 150 Cordycepose, 52 Denitration, 151 Cordyceps militaris (Linn.) Link, 52 oxidative, of cellulose, 42 Corynebacterium diphtheriae, 67 selective, 37 Counter-current distribution, 296 2-Deoxyglycosides, of amines, 96-98 Cuprammonium rayon, tosylation, 122 2-Deoxyhexomethyloses, synthesis, 89-91 Cuprammonium-glycoside complexes, 13, Deoxyhexonic acids, lactones, 99 14 preparation, 99 Cyanohydrin reaction, 233, 248, 249, 255 Deoxypentonic acids, lactones, 99 Cyanophyceae, 316 preparation, 99 Cyclopentanol, cis-2-amino-N-(p-nitroDeoxypentose, enzymic synthesis, 67 benzoy1)-, 6 Deoxypentosenucleic acid, -, trans-2-amino-N-(p-nitrobenzoyl)-, 6 of avian tubercle, 49 -, cis-2-amino-0-(p-nitrobenzoyl)-,hyof bacteria, 49, 50 drochloride, 6 of herring sperm, 50 Cymarose. See D-ribo-Hexose, 2,6-dideof Mycobacterium tuberculosis, 49, 50 oxy-3-0-methyl-. of viruses, 49 of wheat germ, 49 Cysteine-sulfuric acid test, 65 Deoxyribose, nucleotides, 50 Cytosine, Zdeoxy-D-ribosyl-, 50, 51, 52 Deoxysugars, mercaptals, 92 deaminase, 50 2-Deoxysugars, biosynthesis, 66-68 -, 3-(2-deoxyribosyl)-5-methyl-,49, 50 chemistry, 45-105 -, 5-methyl-, in molasses, 308, 313 detection, 53-66 0-glycosides, 91 D nomenclature, 46-49 occurrence and isolation, 49-53 Damson gum, aldobiouronic acid, 226 phosphoric esters, 101 Deacetonation, 143, 144, 145, 146, 148, synthesis, 66-91 149 synthesis by Fischer-Sowden method, Deacetylation, 99, 146, 159-161 73-75 Bergmann-Schotte, 70 synthesis by glycal method, 68-73 selective, 33 synthesis from 2,3-anhydrosugars, 75with piperidine, 33 83 Zemplbn-l'acsu, 70, 99 transformation products, 91-101 Deacylation, 161 3-Deoxysugars, 0-glycosides, 92
376
SUBJECT INDEX
Design dyeing, use of sulfonylated cellulosic fibers, 115 Desose, the term, 47 Desulfation, 319, 320, 329, 336 Desulfonylation, reductive, 161-165 Desulfonyloxylation, 7, 8 ease of, 211 reductive, 161-165 Desulfonyloxylation-iodination. See tables on pages 182-184, 187-188, 194-195,198, 199-200, ,902,and ,907208.
conditions, 192 mechanism, 203, 204 Desulfuriaation, reductive, 75, 76, 78, 80, 87 Detosylation, 152 Detosyloxylation, 7, 8, by methanolic hydrogen chloride, 146 by sulfuric acid, 145 Detritylation, 144, 146, 150 Deuterium oxide, 19 Dextran, 283, 295 Dextransuorase, 283, 287 Dextrin, limit, monoformate, 36 Dextrins, oxidation of, 248 Diazouracil test, 285, 290 2,3-Dideoxysugars, configurations of alkyl glycosides, 93 0-glycosides, 92 synthesis, 88-89 Diethylamine, 81 in catalytic deiodination, 157, 158 Differential adsorption, on activated carbon, 17 Difructose dianhydrides, 305 D-Diginose. See D-lyzo-Hexose, 2,6-dideoxy-3-0-methyl-. D-Digitalose. See D-Galactose, 6-deoxy3-O-methyl-. Digitoxose. See n-Allose, 2,6-dideoxy-. Diheterolevulosans. See Difructose dianhydrides. Dilsea edulis, 328, 350 preparation of mucilage, 328 Dilsea edulis mucilage, 328-330 triacetate, 329 acetylated and desulfated, 329 composition, 328-329 desulfated and methylated, 329
ester sulfate of, 329 methylated, 329 structure, 329, 330 Diphenylamine reaction, 53 adaptations, 55 colors produced, 55 Diphenylbenzidine Violet, 57 Disaccharides, separation from monosaccharides, 15 Dische reagent, 53 Dische test, 53-58 curves for light-absorption, 57, 58 Double bond, effect on reactivity of sulfonyloxy groups, 195 Double-bond formation, in detosyloxylation, 27 in sulfonylation, 126, 127 Dreywood anthrone reagent, 66 Dulcitol. For racemic derivatives see under Dcgalactitol. -, 1,3,4,6-tetra-0-acetyl-2,5-di-0-tosyl-, 207, 209 -, lI3:4,6-di-0-benzylidene-2,5-di-0tosyl-, 120, 208, 209 -, 2,3,4,5-di-O-benz ylidene-l ,6-di-Otosyl-, 187 -, 2,3,4,5-di-O-isopropylidene-l,6-di-Otosyl-, 187 reaction with pyridine, 120 -, 1,3:4,6-di-O-methylene-2,5-di-Otosyl-, 208, 209 -, 2,6-di-O-tosyl-, 207, 209 Dumontia incrassata, mucilage, 347 Dumontiaceae, 347 Dumontiaceae, Cryptonemiales, Florideae, 328
E E i s a i a bicyclis, 344, 346 Electroreduction, 101 Emulsin, 261 Enzymes, of cane juice, 296 “Epiglucosaminide,” methyl. See 8-DAltroside, methyl 3-amino-3-deoxy-. D-Epirhamnitol. See D-Glucitol, 6deoxy-. meso-2,3-Epoxybutane. See Erythritol, 2,3-anhydro-l,4dideoxy-.
BUBJECT INDEX
Equilibrium constants, of acetates of primary and secondary alcohols, 4 Erlose. See p-n-Fructofuranoside, 4-an-glucopyranosyl-a-D-glucopyranosyl. Erythritol, in molasses, 306 -, 2,3-anhydro-1, Pdideoxy-, 176 -, 1,2,3,4-tetra-O-tosyl-, 201 D-Erythrose, 74 -, 2,4-0-benzylidene-, 74 Eschei-ichia cnli, 67, 104 Ester sulfate, of carrageenin, 335, 336 of fucoidin, 340 Esterification, partial, 15 selective, 24-38 Esyl, the term, 109 Ethane, 1,2-bisacetylthio-, 214 -, 1,2-ditosyIoxy-, 187, 214 Ethanol, tribromo-, conjugation of, 258 Etherification, selective, 16-24 Ethers, of carbohydrates, 16-24 Ethylene glycol, di-0-tosyl-, 187, 214 Ethylene-imine ring, opening, 8 Ethylene-oxide ring, 7, 8 formation, 171 scission by sodium methoxide, 78 scission by sodium methylmercaptide, 75-78, 79 Ethylmagnesium bromide, 82, 149 Euxanthic acid, 251, 254, 261 Euxanthone (3,6-dihydroxyxanthone), 251, 252
377
D-Fructomethylose. See D-Fructose, 6deoxy-. u-Fructopyranose, penta-0-acetyl-p-, 305 -, 1,2:4,5-di-U-isopropylidene-3-0tosyl-, 116 D-Fructopyranoside, methyl, 280 “Fructosaccharase,” 279 keto-D-Fructose, acetate, 305 D-Fructose, 6-deoxy-, 157 -, 1,6-dideoxy-l-iodo-2,3-O-isopropylidene-, 190 -, &deoxy-2,3-0-isopropylidene-l-0tosyl-, 162, 190 6-iodo derivative, 191 -, 3-~~-~-glucopyranosyl-, (Turanose), 281 -, 2,3:4,5-di-O-isopropylidene-,167 1-tosylate, 164, 167, 190 -, 1,6-di-O-tosyl-, 26 2,3-0-isopropylidene acetal, 162, 191 ~-Fructose-l-C~~, 19 8-D-Fructoside, pheny13,4,5-tri-O-acetyl1-0-mesyl-, 190 Fuchsin-sulfurous acid reagent, 63 L-Fucitol. See L-Galactitol, 6-deoxy-. Fucoidin, 316, 317, 340-344 composition, 340-341 desulfated, 343 methylated, 341 structure, 341-344 L - F U C O - ~ - ~ 40 C~OSC, Fuconic acid, 3-O-methyl-~-,lactone, 341 -, 3-0-methyl-b, amide, 341 lactone, 341 F -, 2,3-di-O-methyl+, 342 I ,4-lactone, 342 Feulgen reaction, 61-64 -, 2,3,4tri-O-methyl-~,1,5-lactone, 342 Finkelstein’s reagent, 180 Fucosan, 340 Florideae, 317 Fucose. See a k o Galactose, 6-deoxy-. Fluorone, 2,6,7-trihydroxy-, 9-methyl-, combined, estimation of, 340 66 L-, 340, 343 -, 9-phenyl-, 66 -, 3-0-methyl-~-, 341 Formic acid, preferential esterification 2-deoxy derivative. See D-lyzo-Hexby, 36 ose, 2,6-dideoxy-3-0-methyl-. D-Fructofuranose, 1,3,4,6-tetra-0-, 2-0-methyl-b, 341 methyl-, 281 -, 3-O-methyl-~-, 342, 343 &D-Fructofuranosidase, 282 -, 2,3-di-O-methyl-~-, 342, 343 n-Fructofuranoside, 4c~-D-glUCOpyranO- a-L-Fucoside, methyl 3,4-di-O-methyl-, syl-a-D-glucopyranosyl p-, 290 342 -, methyl, 280 -, methyl 2,3,Ptri-O-methyl-, 341, 342 -)
378
SUBJECT INDEX
amide, 325 2-deoxy-3,4,6-tri-O-methyl-~-, lactone, 99 Fucus, 340 -, 2-deoxy-3,5,6-tri-O-methyl-~-,lactone, 99 Fucus spiralis, 341 -, 2,6-di-O-methyl-~-, amide, 338 Fucus vesiculosus, 340, 341 Fumaric acid, in Louisiana cane juice, 314 -, 2,3,6-tri-O-methyl-n-, l,4-lactone, 329 Funorin, 316 -, 2,4,6-tri-O-methyl-n-, 324 2-Furaldehyde-barbituric acid, test for 1,5-lactoneJ 324 p-D-Galactopyranose, 1,6-anhydro-2-0pentose, 335 Furan, tetrahydro-, 7 mesyl-, 172 Furcellaria fastigiata, 350 -, lJ6-anhydro-, 2-sulfate, 172 Furfuryl alcohol, 55 D-Galactopyranoside, ethyl 2-deoxy-a,@-, 70. 92 G -, methyl a-,oxidation of, 240, 245 -, methyl a- and 8-, isomerization by D-Galactal, 3,PO-isopropylidene-6-0methanolic hydrogen chloride, 93 mesyl-, 182 -, methyl p-, oxidation of, 245 -, 3,4-O-isopropylidene-6-O-tosyl-,182 -, methyl 2,3-di-O-acetyl-p-, 132, 133 -, methyl 2,3-di-O-acetyl-6-O-trityl-p-, D-Galactan, of agar, 324 132 Galactaric acid, 318 -, methyl 3,6-anhydro-a-, 325 -, 3,4-di-O-methyl-, 324 Galactitol, 1,5:3,6-dianhydro-~-,171 -, methyl 3,6-anhydro-p-, 322 -, 1,5-anhydro-2,3,4-tri-0-benzoyl-6-0--, methyl 2-deoxy-, 73, 91, 92, 93 tOSyl-D-, 171, 187 triacetate, 73 -, %deoxy-~-, 101 a-anomer, 70 -, 6-deoxy-L-, action of Acetobacter sub- -, methyl 2-deoxy-3-O-methyl-6-O-tosyla-,183 oxydans on, 40 -, l-deoxy-l-iodo-2,3:5,6-di-O-isopro- -, methyl 2,6-di-O-mesyl-a-, 171, 194, pylidene-4-O-tosyl-DL-, 204 196 -, 6-deoxy-2,3,4,5-di-O-isopropylidene--, methyl 6-O-tosyl-a-, 131 -, methyl 2,6-di-O-tosyl-a-, 131, 194, 196 l-O-tosyl-L, 187 -, 2,3:5,6-di-O-isopropylidene-1,4-di-O- n-Galactopyranosiduronic acid, methyl a-,245 tOSyl-DL-, 204 calcium salt, 240 a-D-Galactofuranose, lJ6-anhydro-, 14 a,p-D-GalactoIuranoside, ethyl 2-deoxy-, -, methyl p-, 245 D-Galactosan <1,4 > a < 1,6 >. See a - ~ 92 Galactofuranose, lJ6-anhydro-. -, methyl 2-deoxy-, 92 polymerization, 96 aldehydo-DL-Galactose, 322 Galactomannan, of carob, 225 D-Galactose, dibenzyl thioacetal, 18 of carob-seed gum, 220 diethyl thioacetal, 18 of guar gum, 220 in agar, 318 of guar seeds, 225 in carrageenin, 333, 335 of lucerne seed, 221 in Dilsea edulis mucilage, 328 3-phosphate1 103 Galactonic acid, 3,6-anhydro-2-0-methyl6-phosphateJ 103 G,324 sulfate, barium salt, 319 -, 3,6-anhydro-2, 4-di-0-methyl-P, DL-Galactose, in seaweed, 318 amide, 325 -, 3,6-anhydro-2,5-di-O-methyl-~, 326, LGalactose, in agar, 318, 328 in carrageenin, 335 328 tFucosides, methyl, 341
-, methyl 3-O-methyl-, 341 -, methyl 2,3-di-O-methyl-, 341, 342
-,
SUBJECT INDEX
379
-, 2,6-dideoxy-3-0-methyl-n-. See D6-sulfate, 319, 320 lyzo-Hexose, 2,6-dideoxy-3-0Galactose, hepta-0-acetyl-aldehydo-n-, methyl-. 152, 322 -, 4,6-O-ethylidene-1,2-O-isopropyli-, hepta-0-acetyl-aldehydo-L-, 322 dene-3-0-mesyl-~-, 199 -, hepta-0-acetyl-DL-, 322, 323 -, 4,6-O-ethylidene-l,2-0-iaopropyli-, 2,3,4,5-tetra-O-acety1-6-0-tosyl-aldedene-3-0-tosyl-n, 199 hydO-D-, 152, 156 -, 4n-galactopyranosyl-3,6-anhydro-~-. -, 2,3,4,6-tetra-0-acety1-6-0-tosyl-n-, diSee Agarobiosc. ethyl thioacetal, 156 -, 1,2:3,4di-O-isopropylidene-~-, 236 -, 6-amino-6-deoxy-1,2:3,4di-O-isopro- tosylation, 129 pylidene-D-, 175 -, 1,2:3,4-di-O-isopropylidene-6-0-, 3,6-anhydro-aldehydo-n-,62 mesyl-n-, 182, 183 -, 3,6-anhydro-n-, 319 -, 1,2:3,4di-O-isopropylidene-6-O-tosylphenylosaeone, 324 D-, 113, 116, 134, 144, 164, 165, 175, 177, 181, 183, 212 -, 3,6-anhydro-~-,318, 319-323, 328 -, B-o-mesyl-~-, dibeneyl thioacetal, 151 dimethyl acetal, 320, 322 -, 6-0-mesyl-n-, diethyl thioacetal, 151 phenylosazone, 324 -, 1,6-anhydro-3,4O-isopropylidene-2- -, 2-0-methyl-n-, 19 -, 6-O-methyl-n-, phenylosaeone, 338 0-mesyl-jh-, 145 -, 3,6-anhydro-2-0-methyl-~-, 324, 325, -, di-0-methyl-D-, 329, 330 -, 2,4-di-O-methyl-~-, 19, 337, 339 328 -, 2,6-di-O-methyl-~-, 337, 338 dimethyl acetal, 324 -? 3,6-anhydr0-2,4di-O-methyl-~-, 319, -, 4,6-di-O-methyl-n-, phenylosazone, 324 324, 328 -, 2,3,4-tri-O-mcthyl-n-, 324 -, 3,6-anhydro-2,5-di-O-methyl-~-, 326 -, 2,3,6-tri-O-methyl-n-, 329 dimethyl acetal, 320, 326 125, 316, 318, -, 6-0-benzylsulfonyl-1,2:3,4-di-O-iso- -, 2,4,6-tri-O-methyl-a-~-, 323, 324, 325, 328, 329 propylidene-D-, 163 -, 2,4,6-tri-o-methyl-n-, 337, 339 -, a-deoxy-~-,62, 90 anilide, 329 anilide, 97 -, 2,4,6-tri-O-methyl-~-,333, 339 3-phosphate, 101, 102 anilide, 339 6-phosphate, 101, 103 324, 325, reaction with methanolic hydrogen -, 2,3,4,6-tetra-O-methyl-~-, 326, 329, 337, 339 chloride, 91 anilide, 326 synthesis from n-galactal, 69 -, 2,3,4,6-tctra-O-methyI-~-, 333, 339 p-toluidide, 97, 98 anilide, 339 -, 3-deoxy-n-. See D-Gulose, 3-deoxy-. -, 2,4,6-tri-O-methyl-3-O-tosyk~-~-, -, 6-deoxy-. See also Fucose. 125, 155 -, 6-deoxy-~-, 157 -, 6-O-tOSyl-D-, 183, 319 -, 3,6-di-deoxy-~-, synthesis, 69 -, 6-deoxy-6-hydraeino-1,2:3,4-di-0-iso- diethyl thioacetal, 147, 151 propylidene-D-, 178 -, 6-O-tOSyl-B-D-, 144 -, 6-deoxy-6-iodo-1,2:3,4-di-O-isopro- Galactoside, methyl 2-0-acetyl-3,CO-isopropylidene-6-0-tosyl-a-~-, 183 pylidene-D-, 181 -, 6-deoxy-1,2:3,4-di-O-isopropylidene- -, methyl 2,4-di-O-acetyl-3-0-methyl-60-tOSyl-a-D-, 183 D-, 164 -, methyl 2,4-di-O-acetyl-3-0-methyl-6-, 2-deoxy-3-0-methyl-~-, 90 O-tOSyl-@-D-, 183 -, 6-deoxy-3-0-methyl-~-, 157 in Chondrus ocellatus mucilage, 333
380
SUBJECT INDEX
-, methyl 2,3-di-O-acetyl-4,6-di-O-tosyl- -, methyl 2,6dideoxy-6-iodo-3-0f l - ~ - , 132, 133, 194, 196
methyhi-O-tosyl-a-~-,90
-, methyl 2,3,4-tri-O-acety1-6-0-tosyl-~- -, methyl 2,6-dideoxy-3-O-methyl-a-~-, D-, 161 90 methyl 3,6-anhydro-2-0-mesyl-a-~-, 6-iodide, 90 -, methyl 2deoxy-3-0-methyl-6-0171, 199 tOSyl-a-D-, 90 -, methyl 3,6-anhydr0-2,4di-O-mesyl-a-, methyl 2-deo~y-3-O-methyl-4~6-diD-, 199 -, methyl 3,6-anhydro-2-0-methy1-1~, O-tOSyl-cY-D-, 90, 194, 196 --, methyl 6-deoxy-3-0-methyl-2,4di326 -, methyl 3,6-anhydro-2,4-di-O-methyl- , o-tOSyl-8-D-, 162 -, methyl 6-deoxy-3,4di-O-methyl-2-0fl-~.-, 319, 320 -, methyl 3,6-anhydro-4-0-methyl-2-0toByl-a-G, 162 -, methyl 2,6dideoxy-3-0-methyl-40tOSyl-a-D-, 168 -, methyl 2,3,6-tri-0-benzoyl-4-O-tosyltOSyl-a-D-, 162 p-D-, 199 -, methyl 3, l-O-isopropylidene-a-D-, -, methyl 4,6-0-benzylidene-3-0-carmesylation, 136 bethoxy-2-O-tosyl-a-n-, 160 -, methyl 3,4-0-isopropylidene-2,6-di-, methyl 4,6-O-benzylidene-2-deoxy-a0-mesyl-a-n-, 104, 196 D-, 101 -, methyl 3,40-isopropylidene-2-03-diphenylphosphateJ 102 methyl-6-0-tosyl-a-~-, 167, 183 3-methyl ether, 90 -, methyl 3,40-isopropylidene-6-03-phosphate, 102 tOSyl-a-D-, 183 3-phosphate, acridine salt, 102 -, methyl 3,4-0-isopropylidene-2,6-di3-phosphate, barium salt, 101 0-tOSyl-a-D-, 147, 194, 196 3-tosylate, 199 -, methyl 2,4,6-tri-O-methyl-~-, 337 -, methyl 4,6-0-benzylidene-2-0-, methyl 2,3,4,6-tetra-O-methyl-~-, 326 methyl-3-0-toayl-fl-~-, 162 -, methyl 3-0-methyl-2,4,6-tri-O-tosyl-, methyl 4,6-0-benzylidene-3-08-D-, 194, 196 rnethyk&o-tosyl-a-D-, 168, 179 -, methyl 2,6di-O-methyl-3,4-di-O-, methyl 4,6-0-bensylidene-2-0-tosyltOsyl-a,-fl-D-, 199 Q-D-, 132 -, methyl 4,6-0-benzylidene-3-0-tosyl- -, methyl 4,6-di-O-methy1-2,3-di-OtOSyl-fl-D-, 199 WD-, 132, 180 -, methyl 4,6-0-benzylidene-2-0-tosyl- -, methyl 2,4,6-tri-O-methyl-3-0-tosyla-D-,168 &D-, 132 -, methyl 4,6-O-benzylidene-3-0-tosyl- -, methyl 2,4,6-tri-O-methyl-3-0-tosylb-D-, 168 P-D-, 132, 153 -, methyl 4,6-0-bensylidene-2,3-di-O- a-D-Galactosiduronic acid, methyl 2deoxy-, 100 tOSY1-(Y-D-, 132 -, methyl 4,6-0-bensylidene-2,3-di-O- amide, 100 esters, 100 tOSYl-p-D-, 132 -, methyl 2deoxy-3,4-0-isopropylidene- -, methyl 2-deo~y-3~4-0-isopropylidene-, amide, 100 CY-D-, 100, 103 esters, 100 6-diphenylphosphate, 103 potassium salt, 100 6-tosylate, 183 -, methyl 6-deoxy-3,Il-O-isopropylidene- a-D-Galactosyl chloride, 2,4,6-tri-Omethyl-3-0-tosyl-, 155 2-0-tOSyl-cY-D-, 179 -, methyl 2-deoxy-3-0-methyl-or-~-, 90 D-Galactwonk acid, 236, 237 4,6-O-hexahydrobenzylidene acetal, 90 -, 1,2:3,4.di-O-Lopropylidene-, 237
-,
SUBJE(2T INDEX
381
a-D-Galacturonoside, methyl 2-deoxy-. -, 5,6-anhydro-2,4-O-benzylidene-l-OSee a-D-Galactosiduronic acid, tosyl-, 144 methyl 2-deoxy-. -, 1,4:3,&dianhydro-2,5-di-O-mesyl-, Gastropoda, 339 208, 209, 211 Gelidium Amansii, 317, 318, 319, 320, -, 1,4-anhydr0-6-0-tosyl-, 151, 186 322, 324, 348 -, 1,4:3,6-dianhydro-2,5-di-O-tosyl-,27, Gelidium cartilugineum, 317 177, 208, 209, 211 Gelidium crinale, 320, 322 -, 1,6-di-O-benzoyl-, 35 Gelidium japonicum, 317, 322 -, 6-0-benzoyl-1,3:2,4-di-O-ethylideneGelidium latifolium, 320, 322 B-O-tosyl-, 207 Gelidium pacificum, 317 -. 2,3,4,5-tetra-O-benaoyl-l,6-di-OGelidium subcostatum, 317, 318, 322 tosyl-, 187 Gelase, 340 -, 2,4-0-bensylidene-, 25 Gelose, 317 -, 4,6-0-benzylidene-, 74 Gentianose, 289 -, 2,4-O-bensylidene-l,6-di-O-tosyl-, 25 Giant kelp. See Macrocystis p?jrifera. -, 1,3:2,4di-O-benzylidene-5,6-di-OGigartina chamissoi, 330 tosyl-, 202 Gigartina stcllata, 330, 331, 333, 334, 335, -, 2-deoxy-, 101 336, 338 -, 6-deoxy-, 157 Gloiopeltis, 316 -, 6deoxy-6-iodo-2,CO-methylene-1-0u-Glucal, tri-0-acetyl-, 72, 85, 88 tosyl-, 187 “D-Glucal hydrobromide,” di-0-acetyl-, -, 6-deoxy-6-iod0-2,4:3,5-di-O-methyl72 ene-1-0-tosyl-, 187 -, tri-0-acetyl-, 72 -, 6-deoxy-2,4O-methylene-l-0-tosyl-, D-Glucaric acid, 43, 240, 243, 263 151, 157 -, 1,4-lactone, 231, 233-236 -, 6-deoxy-2,4:3,5-di-O-methylene-1-0monohydrate, 235 tosyl-, 162 -, 6,3-lactone1234, 235 -, l-deoxy-1-nitro-, 73 -, 2,3,4tri-O-methyl-, &lactone, 255 -, 1,3:2,4di-O-ethylidene-5,6-di-O-, tetra-0-methyl-, l,4lactone, 234 mesyl-, 202, 215 -, tetra-0-methyl-, 6,3-lactone, 234 -, 1,3:2,4di-O-ethylidene-6-O-o-tolyl-5D-Glucitol, 101 0-to~yl-,207, 209 -, 2,3,5-tri-O-acety1-3,6-anhydro-l-O- -, 1,3:2,4-di-O-ethylidene-6-O-tosyl-, 152 tosyl-, 187 -, 1,2,3,4tetra-0-acetyl-6-O-benzoyl-5- -, 1,3:2,4di-O-ethylidene-5,8-di-Otosyl-, 202, 215 0-tosyl-, 207, 209 -, 3,4,5,6-tetra-O-acetyl-l,2-dideoxy-, 73 -, 2,4O-methylene-, 136 -, 2,4O-methylene-l,6-di-O-tosyl-, 136, -, 6-8-acetyl-6-deoxy- 1,3:2,4di-0ethylidene-6-thio-5-O-tosyl-, 215 188 -, 3,5-di-O-acety1-6-deoxy-6-iodo-2,40--, 2,4:3,5-di-0-methylene-lI6-di-Omethylene-1-0-tosyl-, 157 tosyl-, 188 -, 5-O-acetyl-l,3:2,4-di-O-ethylidene-6- Glucodesose. See D-Glucose, Zdeoxy-. “ Glucofructosane B.” See ~-D-G~uco0-tosyl-, 187 -, 3,5-di-O-acetyl-2,40-methylene-1,6- pyranoside, l-8-D-fructofuranosyl-~D-fructofuranosyl. di-0-tosyl-, 187 -, 2,5-anhydro-l,6-di-O-benroyl-, 5 D-Glucofuranose, 3-0-acetyl-l,2-0-isopropylidene-a-, 4 -, 1,4anhydro-2,3,5-tri-0-benaoy1-6-0dimolar tosylation, 124 tosyl-, 187 6-trityl ether, 3 -, 1,4anhydro-3(or 2),5-0-benzylidene-, 1,6-anhydro-a-, 14 6-O-t0syl-, 187
382
SUBJECT INDEX
-, 6-O-benzoyl-l,2-0-isopropylidene-3- -, 2,4:5,6-di-O-methylene-3-0-tosyl-, 0-tosyl-a-, 159 methyl ester, 210 5,6-0-monocarbonate, 62 -, 2,4:3,5-di-O-methylene-6-0-tosyl-, 1,2-0-cyclohexylidene-a-,238, 244 methyl ester, 190 1,2-0-isopropylidene-a-, 43, 163, 164, D-Gluconyl chloride, penta-0-acetyl-, 88 170, 171, 232, 236, 237, 238, 243, 248, D-Glucopyranose, polymers, 2-substi346 tuted, 38 6-acetate1 4, 238 -, 1,2,3,6-tetra-O-acetyl-p-,3 6-aminod-deoxy derivative, 175 -, l,a-anhydro-, 10 5,6-anhydride1 163 -, l,B-anhydro-@-, 8, 9, 10 3-benzoate1 4 xanthation, 31 6-benzoate, 4, 128, 131 -, 3,6-anhydro-2-0-tosyl-P-, 176 6-deoxy-6-methylthio derivative, 178 -, 3-P-~-glucopyranosyl-, (Laminari3-me8ylate1 143, 156 biose), 345 3-tosylate1 128, 143, 151, 159, 160, 170 -, 2,3,6-tri-O-methyl, tosylation, 119 6-tosylate1 128, 143, 149, 159, 163, 175, -, 3-O-t0syl-, 109 178, 184, 186 D-Glucopyranoside, o-cresyl 6-0-benzoyl3,6ditosylate, 128 8-, 35 oxidation, 239 -, ethyl, oxidation of, 241 3-sulfate, 170 -, ethyl 0-ethyl-, 29 -, 1,2-0-isopropylidene-3-O-methyl-a-,-, 8-n-fructofurmosyl a-,(Sucrose), 288 6-sulfate, barium salt, 171 -, 1-P-n-fructofuranosyl-p-D-fructo~-Glucofuranoseen-5,6,5-deoxy-1,2-0furanosyl a-,289 isopropylidene-, 186 -, 6-~-~-fructofuranosy~-~-~-fructoa,p-n-Glucofuranosides, methyl 2-deoxy-, furanosyl a-,289 92 -, 6-~-n-galactopyranosyl-~-~-fructopolymerization, 96 furanosyl a-,290 D-Glucofuranuronic acid, 1,2-0-isopro- -, 3-a-~-glucopyranosyl-~-~-fructopylidene-, sodium salt, 249 furanosyl a-, (Melezitose), 281, 288 D-Ghcofuranuronic acid-6-C14, l12-0-iso- -, I-menthyl a-,oxidation of, 245, 248 propylidene-, 6,3-lactone, 249 -, Lmenthyl 8-, oxidation of, 245 n-Glucoheptonic acid, tetra-O-acetyl-2- -, methyl a-,monobenzoate, 31 deoxy-, S-lactone, 88 methylxanthate, 31 -, 2-deoxy-, lactone, 88 oxidation, 239-241, 245-248 L-Glucomethylose, 2-deoxy-. See -.I reaction with carbon disulfide plus Mannose, 2,6-dideoxy-. barium hydroxide, 31 monoxanthate, 31 D-Gluconic acid, 44, 242, 243 6-methyl ether, 219 -, methyl 8-, oxidation of, 240, 245, 246 phenylhydrazide, 234 -, methyl 2,3-di-O-benzoyl-fl-, 35 -, 3-deoxy-, barium salt, 85 -, methyl 2,6-di-O-benzoyl-a-, 31, 36, 131 calcium salt, 85 -, 6-deoxy-6-iodo-2,4:3,5-di-O-methyl- -, methyl 2,6-di-O-benzoyl-8-, 36 -, methyl 2,3,6-tri-O-benzoyl-j3-,35 ene-, methyl ester, 190 -, 2-deoxy-3,4,6-tri-O-methyl-, lactone, -, methyl 2,3-di-O-benzoyl-6-0-trityl-a-, 100 133 -, 2-deoxy-3,5,6-tri-O-methyl-,lactone, -, methyl 4(?)-chloro-4(?)-deoxy-tri-Otosyl-a-, 29, 124 100 -, methyl monochloromonodeoxy-tri-Q. -, 2-keto-, 44, 334 -, 5-keto, 44 tos&3-, 125
-, -, -,
SUBJECT INDEX
-,
methyl 4(?),6-dichlor0-4(?),6-&deoxy-di-0-tosyl-a-, 29, 125 -, methyl 4(?),6-dichloro-4(?), 6-dideoxy-di-0-tosyl-8-, 125 -, methyl 2-deoxy-a-, 70, 91 -,methyl Zdeoxy-, a and j3 anomers, 92, 93 -, methyl 6-0-mesyl-a-, 25 -, methyl 6-O-methyl-, 18 -, methyl 2,3-di-O-methyl-P-, 139 -, methyl 2,3,6-tri-0-methyl-cr-, 4 -, methyl 2-O-tosyl-p-, 160 -, methyl 3-0-tosyl-j3-, 161 -, methyl 6-O-tosyl-a-, 24, 159 -, methyl 6-O-tosyl-j3-, 24, 117, 183 -, 2‘-naphthyl j3-, oxidation of, 245 -, phenyl 8-, 10 tetraxanthate, 31 -, phenyl 6-0-benzoyl-j3-, 35 -, phrnyl 2-0-methyl-j3-, 10 D-Glucopyranosiduronic acid, bornyl p-, 254, 262 -, ethyl, 241 --, I-menthyl a-,245 -, I-menthyl 8-, 245 -, methyl (Y-, 239, 247, 248 -, methyl @-, 240 -, 2’-naphthyl j3-, 245 8-D-Glucopyranosyl phenyl sulfone, 10 Glucopyranosylammonium halides, 8 “ Glucosaccharase,” 279 D-Glucosaccharic acid. See D-Glucaric acid. D-Glucosan <1,4> a <1,6>. See a-DGlucofuranose, 1,6-anhydro-. Glucosan, 2,3,4-tri-O-phenylsuIfonyl-, 192 D-Glucose, diborate, 15 1,l-chlorohydrin, 38 diethyl thioacetal, monosodium derivative, 18 in hot-water extract of carrageen, 334 6-methanesulfonate, 26 N-j3-naphthylsulfonylhydrazone, 108 oxidation of, 43, 44 phenylosaaone, 10, 218 N-phenylsulfonylhydrazone, 108 1-phosphate, 103 a-,1-phosphate, dipotassium salt, 246 6-phosphate, 38
383
reaction with liquid hydrogen chloride, 38 reaction with polyphosphoric acid, 38 6-substituted derivatives, 38 -, 1,2,3,4-tetra-O-acetyl-j3-,4, 238 6-benzylsulfonate, 163 6-cyanothio-6-deoxy derivative, 213 -, 1,2,3,6-tetra-O-acetyl-8-,4 -, 2,3,4,6-tetra-O-acetyl-,reaction with piperidine, 33 -, 1,2,3,4,6-penta-0-acetyl-a-,reaction with piperidine, 33 -, 1,2,3,4,6-penta-O.-acetyl-8-, 163 reaction with liquid hydrogen bromide, 38 reaction with piperidine, 33 -, hepta-0-acetyl-aldehydo-,322 -, 3-0-acetyl-5-(tetra-O-acetyl-~-~-glucopyranosyl)-1,2-0-isopropylidenea-,6-acetate, 214 6-methanesulfonate, 214 6-tosylate, 214 -, 5-O-acetyl-3-(tetra-O-acetyl-~-~-glucopyranosy1)- 1,2-0-isopropylidene-, 6-acetate, 214 6-methanesulfonate, 214 6-tosylate, 214 -, 3,4,6-tri-O-acetyl-l,2-anhydro-,10 -, 1,2-di-O-acetyl-3,6-anhydro-5-0tosyl-, 150 -, 4,6-di-O-acetyl-2,3-didehydro-2,3dideoxy-, 88 -, 3,5-di-O-acetyl-6-deoxy-6-iodo-1,2-0isopropylidene-a-, 186 -, 1,3,4-tri-0-acetyl-6-deoxy-6-iodo-2-0tosyl-a-, 156 8-anomer, 156 -, 5-0-acetyl-l,2-0-isopropylidene-3-0methyl-6-0-trityl-a-, 3 -, 6-O-acetyl-l,2-0-isopropylidene-5-0tosyl-a-, 200 -, 3-0-acetyl-1,2-0-isopropylidene-5,6di-0-tosyl-a-, 152 -, 3,5-di-0-acetyl-l,2-0-isopropylidene6-0-tosyl-a-, 184 -, 5,6-di-0-acetyl-l,2-0-isopropylidene3-O-tOsyl-a-, 149, 170 -, 5,6-di-O-acetyl-3-O-mesyl-a-,1,2-0(a-amyloxyethylidene) acetal, 154
384
GUBJECT INDEX
1,2-0-(a-benzyloxyethylidene) acetal, -, 6-O-benzoyl-l,2-0-isopropylidene-50-tosyl-a-, 131 154 3-benzyl ether, 173 1,2-0-(a-bromoethylidene)acetal, 150, 3-tosylate, 131, 149 154 -, 5,6-di-O-benzoyl-l,2-0-isopropylil,%O-isopropylidene acetal, 150 dene3-0-tosyl-a-, 149, 159 1,2-O-(a-methoxyethylidene)acetal, -, 6-0-benzoyl-2-0-methyl-, diethyl 154 thioacetal, 35 -, 1,2,3,4-tetra-O-acetyl-6-O-mesyl-a-, -, 4,6-O-benzylidene-, 74 183 -, 3,5-0-benzylidene-l,2-O-cyclohexyli8-anomer, 120, 183 dene-a-, 238 -, 1,2,3,6-tetra-O-acetyl-4-0-mesyl-, -, 3,5-O-benzylidene-l,2-0-isopropyli198, 199 dene-a-, 237, 238 -, 2,3,4,6-tetra-0-acetyl-l-O-mesyl-~-, 6-acetate, 238 111, 142 6-amino-6-deoxy derivative, 175 -, 1-0-acetyl-2,3,6-tri-O-methyl-5-Obdeoxy-6-fluoro derivative, 212 tosyl-, 147 6-deoxy-6-iodo derivative, 112 -, 4-0-acetyl-2,3,6-tri-O-tosyl-,155 6-ethanesulfonate, 212 and 8 anomers, 125 6-methanesulfonate, 175, 184, 212 8-1-acetate, 193, 194, 196 -, I,3,4-tri-O-acetyl-2,6-di-O-tosyl-c~-, 6-tosylate, 112, 184 -, 5,6-O-benzylidene-1,2-0-isopropyli26, 131, 176, 194 dene-a-, 3-methanesulfonate, 156, 8-anomer, 26, 131, 155, 194 212 -, 1,2,3,6-tetra-0-acetyl-4o-tosyl-,160 3-tosylate, 197 -, 1,3,4,6-tetra-O-acetyl-2-0-tosyl-a-, -, 6-chloro-6-deoxy-l,2-0-isopropyli156 dene-3-0-methyl-5-0-tosyl-a-, 124, 8-anomer, 156 197 -, 2,3,4,6-tetra-O-acetyl-l-O-tosyl-"a"-, -, 1,2:5,6-di-0-cyclohexylidene-3-0111 phenylsulfonyl-a-, 200 8-anomer, 142 -, 1,2,3,4tetra-O-acetyl-6-O-trityl-, 238 -, 2,3-didehydroxy-. See D-er?jthroHexose, 2,3-didehydroxy-. -, 3-amino-3-deoxy-, 176 1,2:5,6-di-O-isopropylidene acetal, 176 -, 2-deoxy-, 46, 47, 48, 85 -, 5,6-anhydro-l,2-0-isopropylidene-3- anilide, 97 tetrabenzoate, 92 0-methyl-a-, 171 -, 3,6-anhydro-l,2-0-isopropylidene-5- 3,4,5,6-tetrabenzoate, dimethyl acetal, 87 0-to~yl-a-,117, 150, 163, 168, 170 benzylphenylhydrazone, 73 -, monoanhydro-mono-0-tosyl-, 145 5,6-monocarbonate, 62 -, 1,6-anhydro-2,3,5-tri-O-tosyl-8-, 200 dimethyl acetal, 87 -, 1-0-benzoyl-, 255 3-methyl ether, 69 b-anomer, 256 3,4,6-trimethyl ether, 69 -, 6-O-benzoyl-, dibenzyl thioacetal, 35 p-nitrophenylhydrazone, 69 diethyl thioacetal, 15, 16, 35 preparation, 73 -, 2,6-di-O-benzoyl-, 15, 36 reduction of, 101 -, 1,2,3-tri-O-benzoyl-, 35 synthesis from glycal, 69 -, 1,2,3,6tetra-O-benzoyl-,35 p-toluidide, 97 -, 3,4,5,6-tetra-O-benroyl-, diethyl thio-, 3-deoxy-, 85 acetal, 36, 86 -, 6-deoxy-, sulfonic esters, 158 -, pentabenzoate, 36 -, 60-benzoyl-l,2-0-isopropylidene-5- -, 6-deoxy-6-fluoro-1,2-O-isopropylidene-3,5-di-O-meayl-a-, 212 O-methyl-3-O-tosyl-a-, 170
SUBJECT INDEX
385
-, 4,6-0-ethylidene-, 74 -, 2,3,4,6-tetra-O-methyl-, 281, 334,345, -, “isodiacetone-.” See a-D-Glucose, 346 1,2:3,5-di-O-isopropylidene-. -, 2,3,6-tri-O-methyl-4-0-tosyl-, 155 -, 1,2-O-isopropylidene-a-, 1-acetate, 147 3-benzyl ether, 173 -, 3-O-t0~yl-, 158 3,5-borate, 238 2,4,6-triacetate, 8-anomer, 154 3-mesylate, 5,6-carbonate, 200 1,2,4,6-tetraacetate, 149 3,5,6-trimesylate, 212 1,2,4,6tetraacetate, p-anomer, 148, &methyl ether, 170 158 5,6-&tosylate, 117, 130, 139, 145, 152, monohydrate, 145, 147 159, 163, 164, 170, 205 6-0-t0~yl-,26 3,5,6-tritosylate, 117, 130, 149 8-anomer, 144 1,2,3,4tetraacetate, a-anomer, 155, -, 5,6-0-isopropylidene-, dibenayl thio183 acetal, 17 1,2,3,4-tetraacetate, 8-anomer, 26, 131, -, 1,2:3,5-di-O-isopropylidene-a-, 167, 155, 158, 183, 213 175 1,2,-O-isopropylidene acetal, 164 6-amino-6-deoxy derivative, 175 19, 259 6-tosylate, 143, 147, 149, 167, 175, 179, ~-Glucose-l-C~4, D-Glucose, hexa-C”, 259 184 -, 1,2:5,6-di-O-isopropylidene-a-, 116, ~-Glucoseen-3,4,3-deoxy-1,2:5,6-di-Oisopropylidene-, 177, 179 161, 169, 346 u-Glucoseen-5,6, 6-deoxy-l,2:3,5-di-O3-benzyl ether, 173 isopropylidene-, 167, 175, 179 3-benzylsulfonate, 163, 164 p-D-Glucose-6-pyridiniurn methanesul3-deoxy-3-hydraaino derivative, 177 fonate, 1,2,3,4-tetra-O-acetyl-63-mesylate, 179, 213 deoxy-, 120 3-j3-naphthalenesulfonate, 116 3-tosylate, 109, 114, 116, 128, 134, 143, Glucosidase, WD-, 280 of Aspergillus oryzae, 281 145, 147, 161-5, 169, 176, 177,179, of malt, 281 192, 200, 213, 214 of yeast, 281 sodium derivative, 113 tosylation, 129 -, B-,B-, 262 -, 1,2-0-isopropylidene-3-O-methyl-5,6- D-Glucoside, benayl 2,3-di-O-acetyl-4,6di-0-tosyl-8-, 194 di-0-tosyl-a-, 124 -, 1,2-0-isopropylidene-3-O-tosyl-~-, -, benayl 3,4,6-tri-O-acetyl-2-O-tosyl8-, 160 5,6-carbonate, 160 -, d-bornyl 8-, 256 -, 2-O-methyl-, 17, 18, 21, 32 -, I-bornyl p-, 256 dibenayl thioacetal, 18 -, ethyl 2,3-didehydroxy-4,6-dideoxydiethyl thioacetal, 18, 21 4,6-diiodo-a-, 196 phenylhydrazone, 21 synthesk of, 36 -, ethyl 2,3-didehydroxy-4-deoxy-4 iodo-6-0-mesyl-a-, 195 -, 3-O-methyl-, phenylosazone, 21, 221 -, 4-O-methyl-, phenylosazone, 219, 220 -, ethyl 2,3-didehydroxy-4-deoxy-4-, 5-O-methyl-, 170 iodo-6-0-tosyl-a-, 195 -, 6-O-methyl-, phenylosasone, 18, 219, -, ethyl 2,3-didehydroxy-4,6-di-O220 mesyl-a-, 194 -, 2,6-di-O-methyl-, 18, 345 -, ethyl 2,3-didehydroxy-4,6-di-O-tosyl-, 3,4-di-O-methyl-, phenylosaaone, 221 a-,194, 196 -, 4,6-di-O-methyl-, 345 -, ethyl 2,3,4,6-tetradeoxy-4,6-diiodo-, 2,4,6-tri-O-methyl-, 345 a-,195 7,
386
SUBJECT INDEX
ethyl 2,3,6-trideoxy-6-iodo-4-O-tosyl- -, methyl 2,3-di-O-rtcetyl-PO-tosyl-fl-, u-, 195 6-nitrate, 155 -, ethyl 2,3-dideoxy-4,6-di-O-mesyl-a-, -, methyl 2,3-di-O-scetyl-4,6-di-O-tosyl&,192 194 -, ethyl 2,3,4-trideoxy-6-0-mesyl-a-, 183 -, methyl 3,4-di-O-acetyl-2,6-di-O-toayl-, ethyl 2,3,6-trideoxy-4-0-mesyl-a-, 200 8-, 171, 194 -, ethyl 2,3-dideoxy-4,6-di-O-tosyl-n-, -, methyl 2,3,5-tri-O-acetyl-6-O-tosyl194 @-, 149 -, ethyl 2,3,6-tri-O-methy1-5-0-tosyl-a-, -, methyl 2,3,6-tri-O-acetyl-4-O-tosyl8-, 213 162 -, Gmenthyl 0-, 256 -, methyl 2,4,6-tri-0-scetyl-3-O-tosyl--, methyl 2,3,4-tri-O-acetyl~-, 3 Q-, 155 banomer, 153, 161 6-tosylate, 161, 183, 213 6-deoxy-6-iodo derivative, 181, 212 -, methyl PO-acetyl-2,3-di-O-toosyl-6-, methyl 2,3,4-tri-O-acetyl-B-, 0-trityl-a-, 150, 159 8-anomer, 150 6-bromo-B-deoxy derivative, 120 -, methyl 2-amino-2-deoxy-3,4,6-tri-O6-nitrate, 38 methyl-& 176 6-tosylate, 183, 213 -, methyl 3,4,6-tri-O-acetyl-p-, 93 -, methyl 2,3,4-tri-O-benzoyl-a-, 3 6-methyl ether, 3 2-nitrate, 38 &tosylate, 159, 183 2-tosylate, 154, 160, 177 -, methyl 2,3,4,6-tetra-O-acetyI-a-,27 -, methyl 2,3-di-O-benzoyl-6-O-dichloro19-anomer, 3, 142, 334 acetyl-4-0-tosyl-a-, 156 -, methyl 2-0-acetyl-4,6-O-benzylidene- -, methyl 2,3-di-O-benzoyl-4,6-di-O3-O-trifluoroacetyl-~,-34 tosyl-a-, 195 -, methyl 3-0-acetyl-4,6-0-benzylidene- -, methyl 2,3,6-tri-O-benzoyl-4-O-tosyl2-0-trifluoroacetyl-a-, 34 LY-, 200 -, methyl 4-0-acetyl-6-chloro-6-deoxy- -, methyl 2,3-di-0-benzoyl-4-0-tosyl-62,3-di-O-tosyl-a-, 29, 123 0-trityl-a-, 133 -, methyl 2,3,4-tri-O-acety1-6-cyeno-, methyl 4,6-0-benzylidene-3-bromo-3thio-6-deoxy-a-, 213 deoxy-2-0-methyl-a-, 81 8-anomer, 213 -, methyl 4,6-0-benzylidene-3-deoxy-2-, methyl 4-0-acetyl-6-deoxy-6-iodo0-tosyl-a-, 200 2,3-di-O-tosyl-p-, 212 -, methyl 4,6-0-benzylidene-3-0-, methyl 4-0-acetyl-dideoxy-diiodomethyl-2-0-tosyl-a-, 162 rnono-O-tosyl-p-, 193 -, methyl 4,6-0-benzylidene-2-O-tosyl-, methyl 2,3-di-O-acetyl-6-deoxy-6Q-, 132, 152, 153 iodo-4-0-tosyl-& 155, 192 -, methyl 4,6-0-benzylidene-3-O-tri-, methyl 6-0-acetyl-2,3,4tri-O-mesylfluoroacetyl-a-, 33, 34 a', 214 2-tosylate, 34, 152, 160 -, methyl 2,3,4-tri-O-acetyl-6-0-mesyl- -, methyl 4,6-0-benzylidene-2,3-bis(Otrifluoroacetyl)-cu-, methenolysie, 33 a-,27 -, methyl 2,3,6-tri-O-acetyl-40-mesyl- -, methyl 2,3,4,6-tetra-O-(a-bromocamB-, 161, 213 phorlr-sulfonyl)-u-, 109 -, methyl 3,4,6-tri-O-acetyl-2-0-methyl--, methyl 3-brom0-3-deoxy-a-, 80 -, methyl 3-chloro-3-deoxy-cr-, 81 u-,3 -, methyl 2,4-di-O-acetyl-3-O-methyl-6- -, methyl 4(?),6-dichloro-4(?),6-diO-to~yl-B-,183 deoxy-cu-, 125 -, methyl PO-acetyl-2,3,6-tri-O-tosyl- -, methyl Pchloro-4,6-dideoxy-6-iodo2,3-di-O-to~yl-c~-,196 &,29, 124, 193, 194
-,
387
SUBJECT INDEX
-, methyl Pchloro-Pdeoxy-2,3,6-tri-O-
a-anomer, 155, 162 tosyl-a-, 195, 196 8-anomer, 155, 162 -, methyl 2-deoxy-, 85 -, methyl 3,4,6-tri-O-methyl-2-O-tosyl8-anomer, 92 B-. 152. 168., 176methyl 6-deoxy-6-fluoro-2,3,4-tri-O- -, methyl 2,3-di-O-methyl-4-0-tosyl-6mesyl-a-, 212 0-trityl-a-, 168 methyl 6-deoxy-6-iodo-2,3,4tri-O- -, methyl 2,3,4,6-tetra-O-p-naphthylmesyl-0-, 195 sulfonyl-a-, 109, 116 methyl 6-deoxy-6-iodo-2,3,4tri-O- -, methyl 2-0-tosyl-p-, 152 methyl-, 180 3,4,6-triacetate, 160 methyl 6-deoxy-6-iodo-2,3-di-O3,6-anhydro derivative, 171 methyl-4-0-phenylsulfonyl-p-, 156, 3,5,6-tribenzoate, 200 191 -, methyl 3-O-tosyl-a,p-, 152 methyl 6-deoxy-6-iodo-2,3,4-tri-O- p-anomer, 152, 153 tosyl-p-, 192 -, methyl 2,3-di-O-tosyl-a-, 159 methyl 6-0-dichloroacetyl-2,3,4-tri- sacetate, 124, 150 0-tosyl-p-, 156, 158 4,6-O-benzylidene acetal, 132 methyl 2,3,4,6-tetra-O-mesyl-a-, 193, -, methyl 2,3-di-O-tosyl-p-, 145 195, 212, 214 Pacetate, 29, 150 methyl 2,3-di-O-methyl-m-, 170 4,6-0-benzylidene acetal, 145 4-acetate, 4 -, methyl 2,3,4-tri-O-tosyl-p-, -, methyl 2,3,4-tri-O-methyl-a-, 4 6-acetate, 156 -, methyl 2,3,4-tri-O-methyl-, 6-bronio6-nitrate, 156 6-deoxy derivative, 180 -, methyl 2,3,4,6-tetra-O-tosyl-a-, 29, 6-nitrate, 180 124 -, methyl 2,3-di-O-methyl-4-0-phenylp-anomer, 125, 154, 192 sulfonyl-p-, 152 -, phenyl 8-, 256, 257 6-nitrate, 156 -, phenyl 2,4,6-tri-O-acetyl-3-O-mesyl-, methyl 2,3-di-O-methy1-4,6-di-O8-, 161 phenylsulfonyl-p-, 139 -, phenyl 2,3,.l-tri-O-acetyl-6-O-tosyl-, methyl 2,3,6-tri-O-methyl-4-08-, 161 phenylsulfonyl-p-, 152, 168 -, phenyl 2-bromo-2-deoxy-a-, 86 -, methyl 2-O-inethyl-3,4,6-tri-O-tosyl--, phenyl 2-deoxy-a-, 86 8-, 139, 195 -, phenyl 4-O-tosyl-p-, 161 -, methyl 2,3-di-O-methyl-4-0-tosyl-~~-, 2,3,6-triacetate, 161 170 phloroglucinyl 8-, 256, 262 -, methyl 2,4-di-O-niethy1-3-O-tosyl-fl-, -, -, 2',4',6'-tribromophenyl 2,3,4,6-tetra162 0-(a-bromocamphor-r-sulfony1)-, -, methyl 2,3-di-O-rnethyl-4,6-di-O109 tosyl-ff-, 22 -, vanillin 2,3,6-tri-O-acety1-4-O-tosyl-, methyl 2,8-di-O-methyl-3,4-di-Op-, 161 tosyl-p-, 172 -, vanillin 2,4,6-tri-O-acety1-3-O-tosyl-, methyl 4,6-di-O-methyl-2,3-di-O8-, 153, 161 tosyl-a-, 192 -, methyl 2,3,4-tri-O-methyl-6-O-tosyl--, vanillin 3,4,6-tri-O-acetyl-2-O-tosyl8-, 161 a-, 184 -, methyl 2,3,6-tri-O-methy1-4-O-tosyl- n-Glucosideen-5,6, methyl 2,3,4-tri-Oacetyl-a-, 212 C Y , ~ - , 147, 150, 151, 168 -, methyl 2,3,6-tri-O-methyl-5-O-tosyl-,-, methyl 4-0-acetyl-2,3-di-O-tosyl-~-, 212 192 I
,
388
SUBJECT INDEX
8-D-Glucoside-&pyridinium p-toluenesulfonate, methyl tri-0-acetyl-6deoxy-, 120 D-Glucosides. See table of specific rotations of D-glucosides on page 266. D-Glucosiduronic acid. See table of specific rotations of D-ghCOSidUTOniC acid derivatives on page 866. See also table of biosynthetic glucosiduronic acid derivatives on pages 264-273. alkyl or aryl, 252, 253 formation, 261-263 formation in VMO,252-254 in urine, 253, 257 isolation from urine, 253 kinetics of formation i n viuo, 260-261 metabolic precursors of, 254 site of formation i n uiuo, 259-260 structure, 254-257 -, aniline, ammonium salt, 245 complex with sodium sulfate, 235 potassium salt, 245 -, bornyl, 232 -, d-bornyl 8-, 256 -, 1-bornyl 8-, 256 -, bornyl 2,3,4-tri-O-methyl-p-, methyl ester, 254 -, camphor, 231, 251, 261 -, euxanthone, 251 -, menthyl, 232, 262 ammonium salt, 254 -, I-menthyl 8-, 246, 256 -, methyl a-,245 8-anomer, 245 -, methyl 2,3,4-tri-O-methyl-a,8-, 254 -, methyl 2,3,4-tri-O-methyl-8-, methyl ester, 255 -, 2’-naphthyl, 259, 262 8-anomer, 246 -, oestriol, 262 -, orcinol, 262 -, phenolphthalein p-, 246 -, phenyl, 252, 254, 256, 261 8-anomer, 246, 252 -, phloroglucinyl 8-, 256 -, vanillic acid, methylated, 255 -, xylenyl, 253 D-G~UCO bromide, S ~ ~ 2,3,4,6-tetra-Oacetyl-, 346 a-anomer, 111, 120
-,
2-0-acetyl-3,6-anhydro-5-0-tosyl-~u-, 149 -, 2,3,4tri-0-acetyl-6-bromo-6-deoxya-,38 -, 3,4,6-tri-O-acetyl-2-deoxy-,72, 98 -, 4-0-acetyl-2,3,6-tri-O-tosyl-a-, 148 conversion to chloride, 155 -, 3,4-di-O-acety1-2,6-di-O-tosyl-a-, 155 -, 2,3,6-tri-O-acety1-4-0-tosyl-a-, 150 -, 2,4,6-tri-O-acety1-3-O-tosyl-a-,120, 148, 149, 153, 154, 155 reaction with dimethylaniline, 119 -, 2,5,6-tri-O-acetyl-3-O-tosyl-a-, 149 -, tri-O-beneoyl-2-deoxy-, 92, 98 D-G~UCOSY~ chloride, 3,4,6-tri-O-acetyl-a-, tosylation, 119 --’ 2,3,4,6-tetra-O-acetyl-,125 -, 4-0-acetyl-2,3,6-tri-O-tosyl-a-, 125 -, 3,4,6-tri-O-acety1-2-O-tosyl-a-,119. 154 conversion to bromide, 148 -, 2,3,4,6-tetra-O-mesyl-, 125 -, 2,3,6-tri-O-rnethyl-4O-tosyl-a-, 151, 155 -, 2,3,6-tri-O-methyl-5-0-tsyl-a,,9-, 161 -, 2,3,4,6-tetra-O-tosyI-a-, 29, 126, 154 D-Ghcosylpyridinium p-tohenesulfonate, 2,3,4,6-tetra-O-acetyl-p-, 120 -, 3,4,6-tri-O-acetyl-2-0-tosyl-,119 -, 2,3,6-tri-O-methyl-4O-tosyl-, 119 8-n-Glucosyltrimethylammonium chloride, 2,3,6-tri-O-methyl-5-O-tosyl-, 162 D-Ghcurone. See D-Glucuronic acid, lactone. D-Ghcuronic acid, 43, 243 barium salt, 239, 240 chemical synthesis, 231-249 cinchonine salt, 248 enryme systems in formation of, 261263 in metabolism, 251-275 in Nature, 251 in treatment of rheumatic diseases, 232 in urine, 231, 232 lactone, 231, 233, 234, 251 lactone, preparation, 244 mechanism of synthesis i n vivo, 257259 metabolic conjugation, 254
SUBJECT INDEX
38 9
1-8-acetyl-2-0-benzoyl-1,&dideoxy1-thio-DL-, 215 2-S-acetyl-l-O-bensoyl-2,3-dideoxya - t h i o - ~ t ,215 1,2-di-S-acetyl-l,2,3-trideoxy-l,2dithio-DL-, 215 1-0-acetyl-,2,3-di-O-tosyl-~~-, 112, 215 1,2-anhydro-3-deoxy-, 140 l-0-beneoyl-3-deoxy-2-O-tosyl-,207, 209, 215 2-O-benzoyl-3-deoxy-l-0-tosyl-, 187, 215 -, 1,3-0-benzylidene-2-0-tosyl-,208, 209 -, 3,5-O-ben~ylidene-l,2-0-cyclohexyli- -, l-bromo-l-deoxy-2,3-O-isopropylidene-, 211 dene-a-, 238 -, camphor. See D-Glucosiduronic acid, -, 1-chloro-I-deoxy-, 122 -, 1,3-dichloro-2-0-p-chlorophenyl~ulcamphor. fonyl-l,3-dideoxy-, 122 -, 1,2-0-cyclohexylidene-a-,calcium -, 2-deoxy-. See Triitol, 2-deoxy-. salt, 245 -, 3-deoxy-l,2-di-0-mesyl-~~-, 215 lactone, 238, 245 -, 3-deoxy-l-0-tosyl-~k, 140 sodium salt, 245 140 -, 1,2-O-isopropylidene-a-, 232,237, 239, -,-, 3-deoxy-2-0-tosyl-~t, 3-deoxy-1,2-di-O-tosyl-~~-, 215 243, 244 -, 2,3-dideoxy-l-O-tosyl-, 206 barium salt, 244 -, 2,3-0-isopropylidene-l-O-tosyl-~-, 175 3,5-0-beneylidene acetal, 237 DL mixture, 113, 211 calcium salt, 244 DL, reaction with pyridine, 119 sodium salt, 244 -, 1,3-di-O-rnethyl-, xanthation, 31 -, 1-0-veratroyl-, 256 -, l-O-methy1-2,3-di-O-tosyl-, 201 D-Glucuronic acid-g-C“, 6,3-lactone, 249 -, 1,3-di-O-tosyl-, 135 8-D-Glucuronidase, 240, 261-263 -, 1,2,3-tri-O-tosyl-, 115, 135, 201 of spleen, 258 Glyceritol-1-C“, 259 Glucuronides, ester. See D-Glucuronic Glycerol. See Glyceritol. acid, 1-0-acyl-. Glycerose, 2,3-0-isopropylidene-~-, 67, ether. See D-Glucosiduronic acid, 83, 84, 85 alkyl or aryl. -, 3-C-phenyl-, 11 t(deztro)-Glutamine, 297, 302 -, S - O - t o s y l - ~ ~diethyl , acetal, 204 Glutaric acid, D-arabo-trimethoxy-, 229 -, 2,3-di-O-tosyl-~t,204 bismethylamide, 229 diethyl acetal, 148, 204 -, xylo-trimethoxy-, 255 Glycogen, 258 “ Glutose,” 305 Glycolaldehyde, 240 Glycals, mechanism of formation, 71 Glycolic acid, in Louisiana cane juice, 314 preparation, 68 Glycols, Glyceraldehyde. See Glycerose. boric acid complexes, 14, 15 D-Glyceric acid, 3-deoxy-2-0-phenylsulcomplexes, 13-16 fonyl-, methyl ester, 147 cuprammonium complexes, 14 Glyceritol, from cane juice, 300 reaction with aldehydes, 14 --, l-O-acetyl-2,3-di-S-acetyl-2,3-direaction with ketones, 14 deoxy -2, a - d i t h i o - ~ t ,2 15 p-Glycopyranoses, 1,6-anhydro-, 9 origin in vivo, 257-259 sodium salt monohydrate, isolation, 245 p-toluidine-ammonium complex, 246 -, “acetobromo-,” lactone, 252 -, 1,2,3,4-tetra-O-acetyl-,238 -, 2,3,4-tri-O-acetyl-l-O-benzoyl-~-, methyl ester, 256 -, 2,3,4-tri-0-acetyl-l-bronio-l-deoxy,methyl ester, 256 -, 1-0-acyl-, 252, 253, 255. See also table for “Eater D-Glucuronides” on page 271. -, 1-0-benzoyl-8-, 252, 255, 256
390
SUBJECT INDEX
Glycopyranosides, methyl. See table of molecular rotations on page 94. -, methyl 2-deoxy-. See table of molecular rotations on page 94. -, phenyl P-D-, 9 Glycosans < 1,5> B < 1,6 >. See p-Glycopyranoses, 1,6-anhydro-. Glycose, bis-6-deoxy-, disulfides, 213 Glycoseen derivatives, 166 Glycoside formation, 146 Glycosides, cardiac, 53 cuprammonium complexes, 13, 14 Koenigs and Knorr synthesis, 6 methyl, oxidation of, 41 -, methyl 2-deoxy-, 69 -, pyrimidine 2-deoxy-, 86 Glycosiduronic acids, methyl, 41 Glycosyl halides, poly-0-acetyl-, 6 effect of sulfonyl groups on reactivity, 154 formation, 148-151 Glycuronosides. See Glycosiduronic acids. Glyoxal, phenylosazone, 10, 89, 329 -, benzyl-, 12 Glyoxalic acid. See Glyoxylic acid. Glyoxylic acid, benzylphenylhydrazone, 248 in cane juice, 314 Gracilaria confervoides, 317, 318, 320, 322 Grignard reagent, 82, 83, 149 Guanase, 104 Guanine, 2-deoxy-~-ribosyl-,51, 52, 104 -, D-ribosyl-, 103 L-Gularic acid, 2,5-anhydro-2,3-0-isopropylidene-, 43 -, 2,3-0-isopropylidene-2-keto-, 243 L-Gulomethylose. See L-Gulose, 6deoxy-. Gulonic acid, L-, 234 -, 3-deoxy-~-,lactone, 85 -, 2-keto-c, 43, 232, 243 Gulose, %deoxy-~-,85 -, 2,6-dideoxy-c, 69 -, 2-deoxy-3-0-methyl-~-, 77 -, 2,6-dideoxy-3-0-methyl-~-. See Dxylo-Hexose, 2,6-dideoxy-3-0methyl-. cu-D-Guloside, methyl 2,3-anhydro-4,6-0benzylidene-, 77, 83, 180
-, methyl 2-deoxy-, 77 4,6-0-benzylidene acetal, 77, 83 3-methyl ether, 90 L-Guluronic acid, phenylhydrazide, phenylhydrazone, 234 Gums, polyuronide, 232 soluble, of cane juice, 293
H Halogens, as oxidants, 43 Hann, Tilden, and Hudson rule, 40 Helix aspersa, 345 Helix pomatia, 345 Hemicelluloses, of cane juice, 293 of corn (maize) cobs, 197, 213 of lima-bean pods, 197, 213 D-g~yCerO-~-D-g~ilO-HeptOpyranOSe, 1,6anhydro-2,3,7-tri-O-tosyl-, 133, 196 4-acetate, 195, 196 -, 1,6:4,7-dianhydro-2,3-di-O-tosyl-, 196 D-"gala-Heptosaminic " acid, N-p-naphthylsulfonyl-, 108 D-g~uco-D-gUlO-HeptOSan < 1,5 >O < 1,6 > . See D-glyCeTO-p-D-gUlOHeptopyranose, 1,6-anhydro-. ,9-D-altro-Heptulopyranose, 2,7-anhydro-, 196 1,3,4,5-tetratosylate, 196 keto-D-gluco-Heptulose, penta-0-acetyl-1deoxy-1-diazo-, 88 Hexane, 1,2:5,6-diepoxy-, 82 Hexene, n-arabo-3,4,5,6,-tetraacetoxy1-nitro-, 73 l-Hexene-4,5,6-triol, 5,6-O-isopropylidene-, 84 Hexitol, anhydro-l,6-di-O-benzoyl-di-Otosyl-, 117 -, 2,5-anhydro-3,4-deoxy-l,6-di-Otosyl-erythro-, 188 -, 1,3,4,6-tetradeoxy-2,5-di-O-tosylerythro(?)-, 207 -, 1,3,4,6-tetradeoxy-2,5-di-0-tosyl-~~three(?)-, 207 Hexitols, anhydro-, 7 -, dianhydro-, 163 -, 2-deoxy-, 101 -, 1,2,3-trideoxy-, 84
SUBJECT INDEX
-,
1,6-dideoxy-l,&diiodo-, 189
39 1
Hydrasine, unsymm. bis- (Meoxy1,2:3,4di-O-ieopropylidene-~-galscHexofuranoses, 3,6-anhydro-, 170 tose)-, 178 Hexomethyloses. See Hexoses, 6-deoxy-. Hydrogen peroxide, for oxidations, 247 Hexonic acid, penta-0-benzoyl-, nitrile, Hydrolysis, selective, 24-38 36 Hydroxyalkylation, with sulfonic esters, -, 3-deoxy-, 85 113 Hexose, 2,3-didehydroxy-~-erythro-,195 secondary, compared Hydroxyl group, ~-, 2-deoxy-~-arabo-. gee D-Glucose, with primary hydroxyl group, 44, 2-deoxy-. 127. 128 -, 2,6-dideoxy-3-0-methyl-~-lyxo-, 90, Hydroxyl groups, of carbohydrates, relative reactivities, 1-44, 127-132 157 -, 2,6-dideoxy-3-0-methyl-~-ribo-,89, Hypobromite oxidation, 44, 342, 346 Hypoxanthine, 2-deoxy-~-ribosyl-, 51,52, 90, 157 103-105 -, 2,6-dideoxy-3-0-methyl-~-zylo-,90, -, D-ribosyl-, 103 157 -, 3,4,6,6-tetra-O-bensoyl-2-deoxy-2- -, 9-(5-deoxy-2,3-0-isopropylidene-5methylthio-fl-D-ribosyl)-, 178 thioethyl-D-, diethyl thioacetal, 86 -, 9-(2,3-0-isopropylidene-5-0-tosyl-j3-, 2-deoxy-2-thioethyl-~-, dimethyl D-ribosyl)-, 178, 182 acetal, 87 3,4,5,6-tetrabenzoate, 87 I Hexoses, separation from pentoses, 15 -, 3,6-anhydro-, 171 L-Iditol, 2,5-anhydro-, 163 -, 5,6-anhydro-, 171 1-tosylate, 144, 145, 163 -, 2-deoxy-, detection, 53 1,6-ditosylate, 188 -, 2,6-dideoxy-, 53 Hexoside, ethyl 2,3-dideoxy-~-erythro-. -, 1,4:3,&dianhydro-, 177 2,5-dimesylate, 208, 209, 211 See D-Glucoside, ethyl 2,3-dideoxy-. 2,5-ditosylate, 208, 209 -, methyl 2,6-dideoxy-6-iodo-3-0-, 2,4:3,5-di-O-methylene-1,6-di-Omethyl-4-0-tosyl-a-D-s2/lo-, 196 tosyl-, 188 8-anomer, 196 D-Idonic acid, 2,4:3,5-di-O-benaylidene-, -, methyl 2-deoxy-3-0-methyl-4,6-di-Omethyl ester, 190 tOSyl-a-D-Zyh-, 195, 196 emesylate, 190 8-anomer, 195, 196 6-tosylate, 189 -, methyl 2,6-dideoxy-3-0-methyl-4-0- L-Idose, 173 tOSyl-cY-D-XylO-, 162 -, 5,6-anhydro-1,2-0-isopropylidene-,3j3-anomer, 162 benzyl ether, 173 -, phenyl anhydro-p-D-, 161 3-tosylate, 162 Hexosides, methyl 2,3-anhydro-, 75 D-Idoside, methyl 4,6-0-benzylidene-3-, methyl %bromo-2-deoxy-~-, isomers, deoxy-D-, 78 85 3-methylthio derivative, 78 3,4,6-triacetate, isomers, 85 -, methyl 4,6-0-benzylidene-2-deoxy-2D-Hexosyl bromide, 3,4,6-tri-O-acety1-2methylthio-a-, 77 bromo-2-deoxy-, 85 -, methyl 6-deoxy-3-0-methyl-2,4-din-ribo-Hexulose, in distillery slop, 305 O-to~yl-@-,164 Himanthalia lorea, 340 -, methyl 3-0-methyl-2,4,6-tri-O-tosylHoney, honeydew, 283 D-, 164 Honeydew, of plants, 277 Indole, 8-methyl-, 59 Hormones, steroid sex-, 252 3-Indoleacetic acid, 59
-, 6-deoxy-6-iodo-l-O-toayl-,189
392
SUBJECT INDEX
3-Indolepropionic acid, 59 Infrared absorption spectra, 141, 142, 241, 312 of N-glycosides, 98 Inosamines, acetyl-, 5 Inositol, epi-, oxidation by Acetobacter suboxydans, 41 -, meso-. See Inositol, my+. -, my+, hexaacetate, 306 in cane juice, 294, 297,302 in molasses, 306,308,313 hexaphosphate, calcium-magnesium salt, (Phytin), 295 Insulin, 258 Interconversions, pyranose-furanose, 15 Intermolecular etherification, in sulfonylation, 112, 117, 118 Inulase, 340 Inulin, 0-allyl-, 24 ‘Inulobiosyl glucose.” See Q-D-G~UCOpyranoside, l-&n-fructofuranosyl-Bn-fructofuranosyl. Invertase, 283,284,285 in cane juice, 296, 302 Ion exchange, 52, 98, 241, 243, 249, 297, 304, 308,309, 312 Iridaea laminarioides. See Iridophycus faccidum. Iridophycus faceidum, 330, 331,333, 334, 335,336, 337,338,348 mucilage, preparation of barium salt, 333 Irish moss, mucilage. See Carrageenin. Isomerisation, by alkali in glass, 4 Isotopically lahelled compounds, C’t, 259 Itaconic acid, 309
Ketoses, formation, a? synthesis, 39 tosylatea of isopropropylidene ketals. 144 Ketotrioses, phenyl-, 12 Kidney, dog, 262 ox, 262 rabbit, 262 role in D-glucuronic acid conjugation, 260 Kidney-liver-lung preparation, dog, 259 Koenigs-Knorr reaction, 92,149,153, 154
L
Laccase, 296, 302 Laminarase, of hyacinth bulbs, 347 of malt, 347 of potato, 347 of seaweed, 347 of snail-juice, 347 of Tethys punt&, 347 of wheat, 347 Laminaria cloustoni, 341,344,347 Laminaria digitata, 340, 344,347 Laminaria flexicaulis, 344 Laminan’ae, 344, 348 Laminaribiose, 345, 346 synthesis, 346 Laminarin, 316,344-347 composition, 344-345 enzymic hydrolysis, 345,347 methylated, 345, 346 partial hydrolysis by acid, 345 structure, 345-347 water-insoluble, 344 water-soluble, 344 Lanthanum chloride, 64 K Lead tetraacetate oxidation, 5, 14,23,29, 35, 38, 86,96, 100, 152 Keller-Kiliani test, 66 Lead dioxide oxidation, 39 Kestose. See n-D-Glucopyranoside, 6-0- Lemania nodosa, 350 n-fructofuranosyl-8-D-fructofurano- Leucofuchsin, 61 syl. Leuconostoc dextranicurn, 295 Ketals, formation, 14 Leuconostoc mesenteroides, 283, 287, 290, Ketohexofuranosea, l16-di-0-tosyl-, 191 295 Ketohexopyranose, 1,3:2,Pdianhydro-b Levan, 290,295 0-tosyl-, phenylosazone, 200 Levansucrase, 287 “Ketose,” apparent, of Chondrus muci- Levoglucosan. See @-D-Glucopyranose, lages, 332,333, 334,335 1,6-anhydro-.
SUBJECT INDEX
Levulinaldehyde, o-hydroxy-, 57, 64 -, w-methoxy-, dimethyl acetal, 56 light absorption, 58 Levulinic acid, 56 from 2-deoxy-~-ribose,51 Levulose. See D-Fructose. Lichenin, 349 Lignin, of bagasse, 299 Lipids, in cane juice, 300, 303 in molasses, 311, 314 Lithium aluminum hydride, 83, 87, 100, 164-165 Lithium bromide, action on sulfonic esters, 211 Lithium chloride, action on sulfonic esters, 211 Liver, as site of D-glucuronic acid formation, 259, 260 dog, 262 guineapig, 258, 260 horse, 262 mouse, 258, 260, 263 ox, 262 rabbit, 260, 262 rat, 103, 258, 260 Lobry de Bruyn and Alberda van Ekenstein transformation, 19
M Macrocystis pyrifera, 340 Maillard reaction, 306 Malic acid, in Louisiana cane juice, 314 Malt extract, dialyzed, 350 Maltose, 350 fl-Maltoside, methyl penta-O-acety1-6,6’di-0-mesyl-, 171 -, methyl 3,6:3r,6r-dianhydro-, monohydrate, 171 Manna, of plants, 277 D-Mannal, 6-deoxy-3-0-methyl-, 90 Mannan, of ivory nut, 225, 229 of Porphyra umbilicalis, 225, 229 of salep, 225, 229 of yeast, 221, 224, 225, 226, 229 D-Mannaric acid, 2,3,5-tri-O-rnethyl-, 224 diamide, 224 Mannitol, D-, 101 benzoylation of, 35 diborate, 15
393
in final molasses, 296 in molasses, 306, 313 1,2,3,5,6-pentanitrate, 37 hexanitrate, 37 -, 2,5-di-O-acetyl-1,6-di-S-acetyl-1,6dideoxy-3,4-O-isopropylidene-l, 6dithio-D-, 215 -, 2,4,5-tri-O-acety1-3,6-anhydro-l-OtOSyl-D-, 188 -, 2-0-acetyl-3,6-anhydro-4,5-O-isopropylidene-l-O-tosy1-D-, 188 -, 2,5-di-S-acetyl-1,4:3,6-dianhydro-2,5dideoxy-2,5-dithio-~-, 2 15 -, 3,4-di-0-acetyl-1,6-di-O-benzoyl-2,5di-0-tosyl-D-, 207, 209 -, l16-di-S-acetyl-1,6-dideoxy-2,3,4,5di-0-methylene- 1,6-&thio-~-,215 -, 2,4,5-tri-O-acetyl- 1,3-0-ethylidene-6O-tOSyl-D-, 188 -, 5-0-acetyl-1,2:3,Pdi-O-isopropylidene-6-0-tosyl-~-, 188 -, 2,5-di-O-acetyl-3,4-O-isopropylidene1,6-di-O-tosyl-~-, 215 -, 1,3,4tri-O-acetyl-2,5-0-methylene-60-tOSyl-D-, 188 -, 2,3,4,5-tetra-O-acetyl-1,6-di-O-tosylD-, 147 -, 1,5:3,6-dianhydro-~-,171 -, l,Panhydr0-2,6 (or 3,6)-di-O-benzoylD-, 5 -, 1,4:3,6-dianhydro-2,5-di-O-benzoylD-, 5 -, 1,5-anhydro-2,3,4-tri-O-benzoyl-6-0tOSyl-D-, 171, 188 -, 1,4:3,6-dianhydro-2,5-dichloro-2,5dideoxy-D-, 21 1 -, 1,4:3,6-dianhydro-2,5-dideoxy-2,5imino-D-, 177 -, 3,6-anhydro- 1-deoxy- 1-iodo-4,5-0isopropylidene-D-, 83, 186, 204 2-tosylate, 203 -, 3,6-anhydro-l-deoxy-4,5-O-isopropylidene-2-0-tosyl-~-, 207, 209 -, 3,6-anhydro-4,5-O-isopropylidene-~-, 136 1,2-dimesylate, 136, 202 1-tosylate, 188, 204 l,a-ditosylate, 202 -, 1,2:3,6-dianhydro-4,5-O-isopropylidene-D-, 83
394
SUBJECT INDEX
1,2:5,6-dianhydro-3,~O-isopropyli- -, 4O-methyl-D-, 219 -, 5,6-di-O-methyl-~-,222 dene-D-, 83 -, 3,6-anhydro-4,5-O-isopropylidene-l- -, 2,5-0-rnethylene-1,3,4,6-tetra-OtOSyl-D-, 205 O-methyl-2-O-tosyl-~-, 207, 209 -, 1,4:3,6-dianhydro-2,5-di-O-mesyl-~-,-, 1,3:4,6-di-O-methylene-2,5-di-OtOSyl-D-, 208, 209 208, 209, 211, 216 -, 1,4:3,6-dianhydro-2,5-di-O-tosyl-~-, -, 2,3,4,5-di-O-methylene- 1,6-di-OtOSyl-D-, 188, 215 27, 177,208, 209 -, 1,6-di-O-pheny1-2,5-di-O-tosyl-n-, -, 1,6-di-0-benzoyl-~-,5, 15, 35 2,3,4,5-tetratosylate, 117, 207, 209 207, 209 -, 1,2,6-tri-0-benzoyl-3,4O-benzyli- -, 3,4-di-O-tosyl-~-, 35 1,6-dibenzoate, 35 dene-5-0-tosyl-~-,207 -, di-O-benzoyl-mono-O-isopropylidene- -, 1,2,5,6-tetra-O-tosy1-~-, 202, 203 di-0-tosyl-D-, 148 ~-Mannitoleen-5,6,202 -, 1,6-di-0-benzoyl-3,4O-isopropyli- D-Mannitoleen-1,2, 3,6-anhydro-4,5-0dene-2,5-di-O-tosyl-~-, 207 isopropylidene-, 186, 204 -, 2,3,4,5-tetra-O-benzoy1-1,6-di-OMannocarolose, 220, 224 Mannofuranoside, methyl CY-D-, 229 tOSyl-D-, 188 2-methyl ether, 218, 220 -, 2,3,4,5-di-O-benzylidene-1,6-di-O6-trityl ether, 224 tOSyl-D-, 147, 188 -, 3,4-0-cyclohexylidene-l,2,5,6-tetra- -, methyl CU#-D-, 229 O-tOSyl-D-, 202 -, methyl 6-deoxy-2,3-0-isopropylidene-, 5,6-didehydroxy-~-. See D-ManniL-, 169 -, 2,3:5,6-di-O-isopropylidene-~-mannotoleen-5,6. -, l,g-dideoxy-~-,sulfonic esters, 158 furanosyl 2,3 :5,6-di-O-isopropyli-, 1,6-dideoxy-k, sulfonic esters, 158 dene-D-, 138 -, 1,6-dideoxy - 1,6-diiodo-3,4-0-isoD-Mannofuranosylpyridinium p-tohenesulfonate, 2,3 :5,6-di-O-isopropylipropylidene-n-, 83 -, 1,6-dideoxy-l-iodo-2,5-0-methylenedene-, 138 3,4di-O-tosyl-~-, 205 Mannogalactan of guar, 197, 213 -, 1,hdideoxy- 1,6-diiodo-2,5-O-methyl- Mannonic acid, D-, ene-3,4di-O-tosyl-n-, 205 1,4-lactone, 229 -, 6-deoxy-2,5-O-methylene-1,3,4-tri-O--, 2,3 :5,6-di-O-hopropylidene-~-,219 tosyl-L-, 205 -, 4-O-methyl-~-, 220 -, 6-deoxy- 1,3:2,5-di-O-met hylene-4-0amide, 220 tosyl-k, 208, 209 1,5-lactone, 219, 220 -, 1-deoxy-l-nitro-D-, 73 phenylhydrazide, 220 -, 1,3-O-ethylidene-2,4,5,6-tetra-Osodium salt, 220 tOSyl-D-, 204 -, g-O-methyl-~-, 220 -, 1,3:4,6-di-O-ethylidene-2,5-di-Ophenylhydrazide, 219, 220 tOsyl-D-, 208, 209 -, 2,3-di-O-methyl-~-,223 -, 1,2:3,4-di-O-isopropylidene-n-,222 1,4lactone, 223 5,G-dimesylate, 202, 203 phenylhydrazide, 223 5,6-ditosylate, 202 -, 3,4-di-O-rnethyl-~-, 223 -, 1,2:5,6-di-O-isopropylidene-n-,85 amide, 221, 223 3,4dimesylate, 207 1,5-lactone, 221, 223 3,4ditosylate, 144, 207 -, 4,6-di-O-methyl-~-,223 -, 3,4-0-isopropylidene-1,6-di-O-phenyl- amide, 222, 223 1,5-lactone, 222, 223 D-, 133 2,5-ditosylate, 133, 145, 207, 209 phenylhydrazide, 223
-,
SUBJECT INDEX
-, 5,6-di-O-methyl-o-, 223 1,4-lactone, 222, 223 -, 2,3,4-tri-O-methyl-~-, 227 amide, 227 1,5-lactone, 224, 225 lJ5-lactone, monohydrate, 227 phenylhydrazide, 227 -, 2,3,5-tri-O-methyl-~-, 227 amide, 227 1,4-lactone, 224, 227 sodium salt, 227 -, 2,3,6-tri-O-met,hyl-~-, 227 amide, 227 1,4lactone, 225, 227 phenylhydrazide, 227 phenylhydrazide hydrate, 227 -, 2,4,6-tri-O-methyl-~-, 228 amide, 225, 228 1,5-lactone, 225, 228 -, 3,4,6-tri-O-niethyl-~-,228 amide, 228 1,5-Iactone, 225, 226, 228 phenylhydrazide, 228 -, 3,4,6-tri-O-methyl-~-,amide, 226 1,5-lactone, 226 -, 2,3,4,6-tetra-O-methyl-~-, 230 lJ5-lactone, 229, 230 phenylhydrazide, 230 sodium salt, 230 -, 2,3,5,64etra-@rnethyl-~-,230 1,4-lactone, 225, 229, 230 phenylhydrazide, 230 sodium salt, 230 p-D-Mannopyranose, 1,Banhydro-, 224 2,3-0-isopropylidene ketal, 218 Mannopyranoside, methyl a - ~ -228 , oxidation, 245, 248 potassium compound, 228 -, methyl p-D-, oxidation of, 245 -, methyl 3,6-anhydro-~-, 171 -, methyl 6-deoxy-2,3-O-isopropylideneG,169 methyl 2,3-O-isopropylidene-a-~-, 221,222 6-trityl ether, 219 -, methyl 2,3-di-O-rnethyl-a-~-,223 -, methyl 6-0-trityl-a-~-,224 D-Mannopyranosiduronic acid, methyl a-,245 -, methyl p-, 245
-.
395
Mannosaccharic acid. See Mannaric acid. Mannose, D-, in molasses, 305 methyl ethers, 217-230 -, tetra-0-acetyl-4-0-methyl-j3(?)-D-, 220 -, 1,6-anhydro-2,3-O-isopropylidene-4&met hyl-p-D-, 2 18 -, a-deoxy-~-. See D-Glucose, 2-deoxy-. -, 2,6-dideoxy-3-0-methyl-~,90, 91 -, 2,3 :5,6-di-O-isopropylidene-~-, 125, 138 chlorination, 125 -, 3,4:5,6-di-O-isopropylidene-~-, dibenzyl thioacetal, 218 2-methyl ether, 218 -, 2-0-methyl-a-~-,218, 220 -, 2-O-methyl-~-, dibenzyl thioacetal, 218 dimethyl acetal, 218, 220 phenylhydrazone, 218, 220 -, 4-O-niethyl-cY-n-, 21&220 tetraacetate, 220 -, 4-O-methyl-u-, benzylphenylhydrazone, 219, 220 -, A-0-methyl-D-, 219, 220 -, 2,3-di-O-methyl-~-,220, 221, 223 oxime, 223 -, 3,4-di-O-methyl-~-,221, 223 monohydrate, a-anomer, 223 1,2-0-isopropylidene ketal, 223 -, 4,6-di-O-methyl-~-, 221-223 -, 5,6-di-O-rnethyl-~-, 222 -, 2,3,4-tri-O-methyl-~-,224, 225, 227 @-, l,g-anhydride, 224, 227 -, 2,3,5-tri-O-methyl-~-, 218, 224 -, 2,3,6-tri-O-methyl-~-, 225, 227 anilide, 225, 227 -, 2,4,6-tri-O-methyl-~-, 225, 227 anilide, 225, 227 p-anomer, 227 a-,monohydrate, 225, 227 -, 3,4,6-tri-O-rnethyl-a-~-, 224-226, 228 -, 3,4,6-tri-O-rnethyl-n-, anilide, 225, 228 -, 2,3,4,6-tetra-O-methyl-~-, 225 anilide, 225, 230 a-anomer, 228-230 -, 2,3,5,6-tetra-O-methyl-~-, 218, 229, 230 -, D-, 1,2-(methyl orthoacetate), 225
396
SUBJECT INDEX
~-Mannosid-B,been,methyl 6-deoxy-2,3D-Mannoses, mono-0-methyl-, 218-220 0-isopropylidene-, 168, 169 di-0-methyl-, 220-223 a-D-Mannosiduronic acid, methyl, 222 tri-0-methyl-, 224-228 brucine salt, 248 -, tetra-0-methyl-, 228-230 2,3,4trimethyl ether, 224 Mannoside, methyl 2-0-acetyl-~-. See D-Mannose, 1,2-(methyl orthoace- D-Mannosyl chloride, 2,3:5,,6-di-O-isopropylidene-, 125, 138 tate). D-Mannuronic acid, 349 -, methyl 2,3,4-tri-O-acetyl-a-~-, 219 lactone, 349 &methyl ether, 219 2,3,4-trimethyl ether, 224 -, methyl 2,3-di-O-acetyl-4-0-methyl-6a-D-Mannuronoside, methyl. See Q-DO-tOSyl-a-D-, 184 Mannosiduronic acid, methyl. -, methyl 2,3-anhydro-j3-~-, 161 -, methyl 2,3,4-tri-O-benzoyl-6-O-tosyl-Melanoidins, 307 Melezitose, 278, 281 a-D-,171, 184 hendecaacetate, 279 -, methyl 4,6-0-benzylidene-a-o-, 221 action of cell-free Proteus enzyme solu2,3-anhydride, 78, 83, 178 tion on, 288 2,3-dimethyl ether, 221 -, methyl 4,6-0-benzylidene-3-deoxy-2- monohydrate, action of Proteus OX2 bacteria on, 284 O-tOSJ’l-cY-D-, 162, 179, 200 -, methyl 6-deoxy-2,3-0-isopropylidene- hendecamethyl ether, 281 structure, 277-290 4-O-tosyl-t, 162, 169, 200 -, methyl 6-deoxy-2,3-0-isopropylidene- Melissyl alcohol, from cane juice, 300 in molasses, 311, 314 5-O-tosyl-1r, 162, 169, 200 -, methyl 6-deoxy-2,3-di-O-methy1-4-0- AS-Menthene, from menthol, 126, 167 Menthol, conjugation of, 258, 259 tosyl-a-G, 162 tosylate, 167 -, methyl 2,3-0-isopropylidene-40Mercaptalation, 151 methyl-6-0-trityl-a-~-, 219 Mercuric chloride, 155, 156 -, methyl P-O-methyl-a-~-, 220 Mesaconic acid, in Louisiana cane juice, -, methyl 3,4-di-O-methyl-a-~-, 223 314 -, methyl 4,6-di-O-methyl-a-~-, 222, 223 Mesyl, the term, 109 2,3-isopropylidene ketal, 222, 223 -, methyl 2,3,4-tri-O-methyl-a-~-,224, Mesyl esters, of carbohydrates, 24-31 Mesylation, selective, 25, 26 227 Metasaccharopentose. See D-XylOSe, 13-trityl ether, 224 2-deoxy-. -, methyl 2,3,5-tri-o-rnethyl-a-~-, 224 Methane, nitro-, 73 6-trityl ether, 224 Methane-U4, nitro-, 74 -, methyl 2,4,6-tri-O-methyl-a-~-, 225 Methancsulfonic acid, tetrahydrofurfuryl -, methyl 2,3,4,6-tetra-O-methyl-a-~-, ester, 212 225, 228, 229 Methanesulfonic anhydride, 139 -, methyl 2,3,4,6-tetra-O-methyl-a, P-D-, Methyl ethers, of polysaccharides, 20-23 225 of sugars, 17-20 -, methyl 2,8,4,6-tetra-O-methyl-j3-~-, Methylation, 152 225, 226, 229, 230 direct selective, 17 -, methyl 2,3,5,6-tetra-O-methyl-a-~-, Methylenation, 151 229, 230 Methylmagnesium iodide, 82, 83 -, methyl 2,3,5,6-tetra-O-methyl-a, P-D-, Methylpentose, in agar, 323 229 of carrageenin, 334, 335 a-~-Mannosid-2,3-een,methyl 4,6-0Microbial count, of sugar-mill products, benzylidene-2,3-dideoxy-,179 310
-, -,
397
SUBJECT INDEX
Migration, acetyl, 2, 3, 4, 5 acyl, 2-7 benroyl, 4, 5, 36, 256 isopropylidene, 158 trifluoroacetyl, 34, 158 Molasses, black strap, 303, 304, 305 the term, 291 cane final. See Cane final molasses. fermented, 310 reducing substances in, 307, 313 refinery black strap, 304 the term, 303 Monosaccharides, condensation with urea, 38 separation from disaccharides, 15 Mucic acid. See Galactaric acid. Mucilage, of Dilsea edulis, 328 of Macrocystis pyrifera, 340 Mucilages, 316 Mucin, as D-glucuronic acid precursor, 259 Mycobacterium tuberculosis, 49 (Human Strain), polysaccharides from, 221 specific somatic polysaccharide of, 226
N Naphthoresorcinol test, 239,242,248,253 Nasyl, the term, 108 Neighboring-group effects, 2-16 Neisseria perflava, 287, 290 Neomannide. See D-Mannitol, 1,5:3,6dianhydro-. Nickel-kieselguhr, 101 Nitration, of cellulose, 42 Nitric acid oxidation, 41 Nitrogen dioxide oxidation, 41 Nucleosides, synthesis, 98 -, 2-deoxyribo-, 79 0
(-)@-Octyl thiol, 179 Odorants, in molasses, 312, 314 Oestrogens, 262, 263 Oldham and Rutherford’s rule, 192, 193, 201 applicability of, 210 Oleandrin, 91
Oleandrose. See Mannose, 2,bdideoxy3-0-methyl-. Olefins, nitro-, 73 Oligosaccharide, nonreducing, from methyl 2-deoxy-cu-~-~-ribofuranoside, 9G Orcinol reaction, 65 Organic acids, non-nitrogenous, in cane juice, 298, 314 in cane molasses, 309, 310, 314 Ortho acid esters, as intermediates, 3, 143 mechanism of formation, 6, 7 Orthoformic acid, ethyl ester, 88 Osazones, formation, 10-13, 151 Osmium tetroxide, 84 Ovomucoid, carbohydrate residue of, 226 Oxalic acid, in Louisiana cane juice, 314 Oxidation, enzymic, 39, 40, 41 of deoxysugars, 99 of D-glucose derivatives, 236-249 selective, 38-44 with Acetobacter suboxydans, structural requirements for, 39 with Acetobacter xylinum, structural requirements for, 39 with bromine water, 99 with chromium trioxide, 152 with halogens, 43, 248 with hypobromite, 324 with lead tetraacetate. See Lead tetraacetate oxidation. with nitric acid, 41, 42, 100 with nitrogen dioxide, 41, 42, 232, 239242 with oxygen, catalytic, 43, 232, 242247 with periodate. See Periodate oxidation. with potassium permanganate, 100, 236-239
P Palladium catalyst, in reduction, 73, 156 Paper chromatography, 15, 66, 84, 285, 287, 297, 308, 339, 341, 346 Paraffins, a-acetoxynitro-, 73 Pectase, 340 Pectic acid, calcium salt, 294
398
SUBJECT INDEX
Pectins, in molasses, 305 of cane juice, 293, 302 Penicillium charlesii G. Smith, 220 1,3-Pentadiene1 127 2,CPentanediol, 127 1-Pentene, n-erythro-triacetoxy-I-nitro-, 74 Pentitol, 1,2,4,5-tetradeoxy-3-O-tosyl-. See Carbinol, diethyl-0-tosyl-. -, anhydro-, 7 Pentosans, in cane juice, 293 in molasses, 305 Pentose, complex with 2-furaldehydebarbituric acid, 335 in agar, 323 of carrageenin, 334, 335 -, 0-benzoyl-, dibenzamides, 36 -, 2-deoxy-D-erythro-. See n-Ribose, 2deoxy-. Pentoses, separation from hexoses, 15 -, 2-deoxy-, detection, 53, 54, 55 D-threo-Pentulose, 2,3-0-isopropylidene1,4-di-O-tosyl-, 196 Periodate oxidation, 10, 14, 23, 24, 29, 30, 36, 38, 74, 100, 105, 221, 248, 281, 289, 320, 324, 325, 329, 330, 342, 346, 347, 348, 349, 350 pH control during, 37 Permanganate oxidation, 100, 224, 236239 Peroxidase, 296, 302 Phaeophyceae, 316 Phenetidine, effect in vivo, 254 Phenol, conjugation of, 258 -, o-amino-, conjugation of, 258, 260 Phenylhydrazine, reaction with sugars, 10, 11 Phloridzin, 257 Phosphate esters, of primary alcohols, resistance to hydrolysis, 38 Phosphodeoxyriboaldolase, 67 Phosphodeoxyribomutase, 104 Phosphoglucomutase, 104 Phosphoriboaldolase, 67 Phosphorolysis, enzymic, 103 Phosphorus oxychloride, 101 Phosphoryl chloride, diphenyl-, 101, 103 Phosphorylase, nucleoside, 104 Phosphorylation, 101 Phytin, 294, 302
in blackstrap molasses, 295 in molasses, 306, 313 Pigments, in cane final molasses, 311, 314 in cane juice, 299, 303 Pine-shaving test, 66 Piperidine, for deacetylation, 33 -, N-(3,4,6-tri-O-acetyl-~-glucosyl)-, 33 preparation of 2-substituted D-glucose derivatives from, 33 -, N-(2,3,4,6-tetra-0-acetyl-~-glucosy1)-, 33 Planteose. See a-n-Glucopyranoside, 6a-D-galactopyranosyl-P-n-fructofuranosyl. Platinized-carbon catalyst, in oxidations, 232 preparation of, 246, 247 Polyhydric alcohols, augmentation of optical rotation, by acid ammonium molybdate, 16 by boric acid, 15, 16 reaction with carbon disulfide plus barium hydroxide, 31 Polysaccharides, condensation with urea, 38 from Mycobacterium tuberculosis (Human Strain), 221 reserve, 316 seaweed, 315-350 selective oxidation of, 241 soluble, of cane juice, 293 structural, 316 Polyuronic acids, 241, 242 Polyvinyl alcohol, sulfonylation, 126, 132 Porphyra laciniata, 318 Porphyra umbilicalis, mannan of, 225 Potassium acetate, action on sulfonic esters, 214 Potassium bromide, action on sulfonic esters, 211 Potassium carbonate, action on sulfonic esters, 180 Potassium cyanide, action on sulfonic esters, 212 Potassium fluoride dihydrate, action on sulfonic esters, 212 Potassium selenocyanate, action on sulfonic ester, 213 Potassium thiocyanate, action on sulfonic ester, 212-213
SUBJECT INDEX
Potassium thiolacetate, action on sulfonic esters, 214-215 Propane, 1,2,3-trichloro-, 122 2,3-Propanediol, ~I-amino-2,3-O-isopropylidene-, 175 1,2,3-Propanetriol, l-(li-pyrazolyl)-, monohydrochloride, 177 I-Propanol, 2,3-dibromo-, acetate, 112 Propionic acid, a-acetoxy-, ethyl ester, 214 -, a-cyanoseleno-, ethyl ester, 214 -, a-cyanothio-, ethyl ester, 213 -, a-iodo-, ethyl ester, 180 -, a-tosyloxy-, ethyl ester, 213, 214 Propiophenone, a,pdihydroxy-, 11 Propylene oxide. See Glyceritol, 1,2anhydro-bdeoxy-. Proteins, in cane juice, 297, 303 Proteus bacteria, 0 x 2 , X2, 0 x 1 9 , X19, OXK, XK, 282, 283 Proleus enzymes, cell-free, 287, 288 Proteus vulgaris 0x2, 283, 284 D-Psicose. See D-do-Hexulose. Purines, in molasses, 308, 313 Pyridine, function in esterification, 123 Pyridine-sulfonic anhydride, adduct, 139 Pyridine-sulfonyl chloride, 1:I adduct, 134, 137
Q Quaternary-salt formation, in sulfonylation, 118-121 rate, 120 Quinaldine test, 65 D-Quinovose. See D-Chinovose and DGlucose, 6-deoxy-.
R Radioisotopic dilution analysis, 19 Raffinose, 289 -, hendeca-0-p-naphthylsulfonyl-, 109 Raney nickel, 79, 81,82,90, 156, 157, 163, 164 Rates of tosylation, comparisons of, 23, 30, 129-130 Rayon, 3 1 tosylation, 122
399
Reactivities, reIative, of hydroxyl groups of carbohydrates, 1-44, 127-132 Red lead oxidation, 39 Reducing sugars, as dibasic acids, 20 Reduction, electrolytic, 235 Reductive desulfonylation, with sodium amalgam. See table on page 162. D-Rhamnal. See D-Mannal, 6-deoxy-. rcRhamnito1, 1-deoxy-. See cMannito1, 1,6-dideoxy-. L-Rhamnofuranoside, methyl 2,3-O-isopropylidene-, 168 L-Rhamnonic acid, tetra-0-benzoyl-, nitrile, 36 Rhamnose, L-. See also cMannose, 6-deoxy-. dibenzyl thioacetal, 18 diethyl thioacetal, 18 3-methyl ether, 91 -, 2-deoxy-L-, synthesis from glycal, 69 3-methyl ether, 69 -, Zdeoxy-3-O-mcthyl-~-, 90, 91 -, 2,3-0-isopropylidene-5-O-tosyl-~-, 26 L-Rhamnoside, methyl 2,3-0-isopropylidene-4-0-tosyl-, 168 -, methyl 2,3-0-isopropylidene-5-0tosyl-, 168 Rheumatic diseases, D-glucuronic acid in treatment of, 232 R hodophyceae, 3 16 Rhodymenia palmata, 335, 348 Ribitol, 3,5-O-benzylidene- l-deoxy- 1 nitro-D-, 74 -, 3-deoxy-, 82 tetrabenzoate, 82 -, 1,5-dideoxy-, 157 -, 1,5-dideoxy-l,5-diiodo-2,4-O-methylene-3-0-tosyl-, 157, 205 -, 2,40-methylene-1,3,5-tri-O-tosyl-, 204 -, 1,3:2,4di-O-methyIene-5-O-tosyl-~~-, 187 D-Ribofuranose, 2,3-0-isopropylidene-, 125 Ribofuranoside, methyl %deoxy-a,p-L-, 92 polymerization, 96 -, methyl 5-deoxy-2,3-O-isopropylidene 5-methylthio-~-, 178
SUBJECT INDEX
400
-,
methyl 2,3-0-isopropylidene-5-0tOsyl-D-, 178, 182 Ribonic acid, D-, lactone, 235 -, 2-deoxy-3,4-di-0-methyl-~-, lactone, 100 -, 2-deoxy-3,5-di-O-methyl-~-, lactone, 100
Ribopyranoside, aniline D-. See Aniline, D-ribopyranosyl-. -, methyl 2,3-anhydro-j3-~-,96 -, methyl 2,3-anhydro-a-~-, 79 8-anomer, 79 -, methyl 2-deoxy-j3-~-,69, 93 -, methyl 2-deoxy-c, 92, 93 Ribose, D-, 235 p-bromophenylhydrazone, 235 conversion to 2-deoxy-~-ribose,50 nucleosides, 50 nucleotides, 50 1-phosphate, 103 5-phosphate, 68 -, a-deoxy-~-, 47, 74, 82, 84, 85, 105. See also D-erythro-Pentose, 2-deoxy-. anilide, 75, 97 I-arsenate, 105 dibeneyl thioacetal, 52 benzylphenylhydrazone, 74 differentiation from u-ribose, 53 4,5-0-isopropylidene acetal, 85 3,Pdimethyl ether, 63 3,bdimethyl ether, 62 occurrence, 49 1-phosphate, 103, 104, 105 1-phosphate, cyclohexylamine salt, 104 3-phosphate, 101 5-phosphate, 52, 68, 101, 103, 105 reaction with indole-3-acetic acid, 59 reaction with indole-3-propionic acid, 59 reaction with 8-methylindole, 59 reaction with tryptophan, 58, 59 synthesis from glycal, 68 -, a-deoxy-~,anilide, 97 phosphates, 103 synthesis from glycal, 68 -, 2,3-dideoxy-c, 89 Riboside, aniline 2-deoxy-~-, 82, 84 -, methyl 2,3-anhydro-j3-~-, 81, 83 -, methyl 2,3-anhydro-j3-~-, 87
-,
methyl %deoxy-j3-n-, 82, 83 3,Pditosylate, 199 -, methyl 2-deoxy-j3-~-,79, 87 -, methyl 3-dcoxy-j3-~-,82, 83 -, methyl 3-dcoxy-j3-~-,79, 87 -, methyl 2-deoxy-3,5-di-0-tosy1-a1~-~-, 194 -, methyl 2-deoxy-3,4-di-O-tosyl-or-t, 96 -, met h y 1 2-deoxy-3,5-di-O-tosyl-a+ , 96 reaction with sodium iodide, 96 -, methyl 2,3-0-iaopropylidene-40tOsJ’l-D-, 199 Ribosides, separation from mixture, 15 -, methyl 2-deoxy-~-,94, 95 3,4-0-isopropylidene acetal, 95 l)-Rihosyl chloride, 3,4-di-O-acetyl-% deoxy-, 99 Ruff and Ollendorf method, 85 “Rum oil,” 312
S “Saccharetin,” 299, 303 Saccharic acid, D-. See D-Glucaric acid. -, D-ghco-. See D-Glucaric acid. -, L-gulo-. See L-Gularic acid and DGlucaric acid. Saccharomyces sake, 320 Saccharurn oficinarum, 292 Saccharum robustum, 292 Saccharum spontaneum, 292 Salicylic acid, 3,5-dinitro-, alkaline, 347 D-Sarmentose. See D-rylo-Hexose, 2,6dideoxy-3-0-methyl-. Schiff’s base, of a nitrogen glycoside, 60 Schiff’s reagent, 62, 63, 64 Sea urchin, jelly coat of, 317 Seaweed polysaccharides, 315-350 Seaweeds, classification, 316 Secondary hydroxyl groups, differential reactivity, 130 Sedoheptulosan. See j3-D-aho-Heptulopyranose, 2,7-anhydro-. Seliwanoff reaction, for ketose, 319, 320, 329, 336 Semicarbaeone formation, 151 Silver fluoride, 156, 212 action on sulfonic esters, 212
SUBJECT INDEX
Silver xanthate, 31 Sitosterol, D-, 301 -, y-, 301 Soda-lime, action on sulfonic esters, 179180 Sodium acetate, action on sulfonic esters, 214 Sodium alkylmercaptides, 75 Sodium amalgam, 81, 85, 101, 161-163, 233, 252. See also table for compounds reductively desulfonylated with sodium amalgam on page 162. Sodium bismuthate, as glycol-splitting reagent, 39 Sodium bisulfite, addition compounds with sugars, 16 Sodium bromide, action on sulfonic esters, 211 Sodium chloride, action on sulfonic esters, 211 Sodium cyanide, C14--labelled,248 Sodium iodide, action on sulfonic esters, 87, 90, 181-211 Sodium methoxide, action on sulfonic esters, 166-175 for deacylation, 160 Sodium nitrite, action on sulfonic esters, 212 Sodium thiocyanate, action on sulfonic esters, 213-214 Sorbitol. See D-GIucitol. L-Sorbomethylose. See L-Sorbose, tideoxy-. t h r b o s e , oxidation of, 43, 232, 243 -, 1-deoxy-1-iodo-2,3 :4,6-di-O-isopropylidene-, 191 -, 6-deoxy-2,3-O-isopropylidene-1-0tosyl-, 157, 162, 190 6-iodo derivative, 157, 191
-,
3,5:4,6-di-O-ethylidene-l-O-tosylketo-, 152
-, 2,3-O-iopropylidene-, 243 oxidation, 43 1,6-ditosylate, 19 1 -, 2,3:4,6-di-O-isopropylidene-,tosylation, 130 I-tosylate, 191 Spleen, dog, 262 ox, 262 rabbit, 262
401
Stacey's test, for galacturonic acid, 100 Stachyose, 289 Stannic chloride, 155 Starch, 197 allyl ether, 24 corn (maize), 242 cyanoethyl ether, 23 Cyanophycean, 350 Floridean, 316, 334, 349-350 6-formate, 36 in cane juice, 294, 302 chlorodeoxy-di-U-tosyl derivative, 123 deoxyiodo-di-0-tosyl derivative, 30 oxidation, 42, 248 potato, tosylated, 213 selective oxidation, 242 soluble, oxidation of, 239, 248 sulfonylation, 115, 116 2,3,6-tritosylate, 123, 148 tosylation, 123 treatment with amides and amines, 38 -, 2,3-di-O-tosyl-, B-deoxy-6-iodo derivative, 148, 212 6-formate, 148 Starches, heat-modified, in molasses, 306 Steric effects, in desulfonyloxylation-iodination, 205 in detosyloxylation, 185 Steric hindrance, 71, 132, 133, 139, 153, 210 Sterols, in cane juice, 300, 303 in molasses, 311, 314 Stigmasterol, 296, 301 in molasses, 311, 314 Streptococcus fecalis, 67 Streptococcus salivarim, 287 Succinic acid, in Louisiana cane juice, 314 -, D ~ - (+)-methoxy-, diamide, 90 -, L ~ - (-)-methoxy-, 76 -, erythro-dimethoxy-, 221, 229 -, D-( -)-threo-dimethoxy-, 255 diamide, 342 Sucrose, 291, 292 octaacetate, 287 acid hydrolysis, 285, 286 allyl ether, 24 crystallization, 303, 304 enzymic-serological test for, 283 from melezitose, 278, 282 hydrolysis of, by hydrochloric acid, 286
402
SUBJECT INDEX
in black strap molasses, 304, 313 heptamethyl ether, 281 octamethyl ether, 281 relation to melesitose, 277-287 X-ray diffraction pattern, 285, 286 Sugar cane, 291, 292 Sugar phosphates, hydrolysis, 166 Sugar-mill products, bacterial count. See table on page 310. Sulfone, p-D-glucopyranosyl phenyl, 10 phenyl b-D-xylopyranosyl, 10 Sulfonic esters, as alkylating agents, 112, 167 physical properties, 140-142 Sulfonic esters of carbohydrates, 24-30, 107-2 15 chemical properties, 142-215 phywical properties, 140-142 stability, in acid environments, 143152 stability in other environments, 152161 Sulfonic group, molar refraction, 141 Sulfonylation, in pyridine, practical details, 127-138 methods, 111-140 optimal conditions, 133-138 unimolar, 128 with metallic salts of sulfonic acids, 111-112 with sulfonic anhydrides, 139 with sulfonyl halides, 112-139 Sulfonyloxy groups, cleavage of, 7, 8, 26 b y amines, 28, 177-178 by ammonia, 28, 175-177 by lithium chloride, 27, 211 by potassium acetate-acetic anhydride, 27, 214 by potassium fluoride-methanol, 27, 212 by pyridine, 27 by sodium amalgam, 28, 161-163 by sodium iodide, 26, 27, 29, 181-211 by sodium methoxide, 28, 166-175 by sodium thiocyanate, 27, 213 Sulfonyloxy groups, primary, replacement by iodine. See tables on pages 182-184,187-188,194-196, 198,and 202.
T D-Talitol, 1,3:4,6-di-O-methylene-2,5& 0-tosyl-, 208, 209 -, 2,4:3,5-di-O-methylene-1,6-di-Otosyl-, 188 6-n-Talopyranose, 1,6:2,3-dianhydro-, 172 p-D-Taloside, methyl 2,3-anhydro-4,6-0benzylidene-, 78 Tannins, in cane juice, 299, 303 in molasses, 311, 314 Tethys puntata, (sea hare), 347 D(?)-glycero-Tetronic acid, 3-deoxy-3,3dimethyl-2-0-tosyl-, 1,4-lactone, 140 Theophylline, 7-(2,3-anhydro-a-~-lyxofuranosy1)-, 80 -, 7-(2,3-anhydro-5-0-trityl-b-~-ribosy1)-, 79 -, 7-(4,6-O-bensylidene-b-~-glucosyl)-, 132 3-tosylate, 132, 200 2,3-ditosylate, 132 -, 7-(3-deoxy-3-ethylthio-a-~-arabinofuranosy1)-, 80
-, 7-(2-deoxy-2-ethylthio-5-0-trityl-p-~arabinosy1)-, 80 7-(3-deoxy-3-ethylthio-5-0-trityl-@-~xylOSyl)-, 80 -, 2-deoxy-~-glucopyranosyl-,72 -, 7-(3-deoxy-p-~-ribofuranosyl)-,80 -, silver, 72, 99 Thermobacterium acidophilus R26, 104 D-Threitol, 2,3-O-isopropylidene-1,4-di0-tosyl-, 187 Thymidine. See Thymine, 2-deoxy-~ribosyl-. Thymine, 2-deoxy-~-ribosyl-, 51, 52 phosphorolysis, 103 Thyminose. See D-Ribose, zdeoxy-. Thymus gland, calf, 103 Titanium tetrabromide, 155 Titanium tetrachloride, 155 Tollens’ 2-furaldehyde assay, 293 Tollens’ naphthoresorcinol test, for hexuronic acids, 100 Toluene, o-nitro-, 251 p-Toluenesulfonic acid, trans-2acetoxycyclohexyl ester, 28 as catalyst, 5
-,
SUBJECT INDEX
403
a-benzylethyl ester, 179 U a-benzyloxyethyl ester, 206 Ultraviolet absorption spectra, 141 n-butyl ester, 212 Unimolar sulfonylation, 128-130, 137 cyclohexyl ester, 206 Uracil, 2-deoxy-o-ribosyl-, 50 esterification, 5 -, 3-(2,3-O-isopropylide1ie-5-O-tosyl-pesters, dipole moments, 142 p-ethoxyethyl ester, 206 D-ribosyl)-, 182 -, 3-(2,3-di-O-methyl-5-0-tosyl-p-~ethyl ester, 206, 212 isopropyl ester, 212 ribosy1)-, 182 -, 3-(2,3-di-O-tosyl-~-~-ribofuranosyl)-, methyl ester, 117, 206 methyl ester, infrared absorption spec198, 199 5-chloro-5-deoxy derivative, 123 trum, 142 methyl ester, ultraviolet absorption -, 3-(2-deoxy-3,5-di-O-tosyl-p-~-ribosyl)-5-methyl-, 194 spectrum, 141 -, 3-(2-deoxy-3-0-tosyl-5-O-trityl-p-~( - )p-octyl ester, 179 ribosy1)-5-methyl-, 198, 199 n-octyl ester, 212 Urea, condensation with mono- and poly8-phenoxyethyl ester, 206 saccharides, 38 n-propyl ester, 206 Uridine, tosylation, 123 tetrahydrofurfuryl ester, 212 -, 5-chloro-5-deoxy-2,3-di-O-tosyl-, 196 p-Toluenesulfonic anhydride, 139 196 p-Toluidine, fl-(2-deoxy-~-galactosy1)-, -, 5-deoxy-5-iod0-2,3-di-O-tosyl-, Urochloralic acid, 251 98 Uronic acid, in agar, 323 Tosyl, the term, 108 in Dilsea edulis mucilage, 328, 329, 330 Tosyl esters, of carbohydrates, 24-31, in fucoidin, 340 108-21 5 Uronic acids, 41, 42 Tosylation, unimolar, 24, 128, 129, 130 in cane juice, 293, 294, 302 dimolar. 25 in molasses, 305, 313 Tosylation-iodination, 23, 30, 180-21 1 Transesterification, intramolecular, 2 V Transglycosidase, enzyme systems, 295 Trehalose, 2,3,4,2’,3’,4’-hexa-O-acetylValcric acid, ~-erythro-l,3,Ptrihydroxy-, 6,6’-dideox~-6,6’-diiodo-, 181 79 -, 6-O-mesyl-, 25 Varrillic acid, methyl ester, 255 heptaacetate, 161 Verbascose, 289, 290 Triitol, 1,3-di-S-acetyl- 1,2,3-trideoxyViscose, 20, 31 1,3-dithio-, 214 Vitamin BN,96 -, 2-deoxy-1,3-di-O-tosyl-, 214 Vitamins, in final molasses, 308, 313 Trimethylamino group, elimination, 7, 8 in raw cane juice, 296, 302 Trioses, 3-C-phenyl-, 11 Triphenylmethyl chloride, 130 W reaction with hydroxyl groups, 16, 25, 158, 159 Waldcn inversion, 5, 8-10, 28, 29, 50, 111, Trityl chloride. See Triphenylmethyl 124, 145, 148, 153, 154, 166, 167, 169, chloride. 172-174, 193, 215. See also table of Tryptophan, reaction, 58-61 some alkaline hydrolyses without Turanose, 278, 279, 281 Walden inversion on page 168. Turbo cornutus, 339 Waxes, in cane juice, 300, 303 Tyrosinase, 296, 302 in final molasses, 300, 311 Tyrosine, 297, 302 in molasses, 311, 314
404
BUBJECT INDEX
Louisiana sugarcane cuticle. See table of chemical data on page 900. Weerman test, 221, 222, 224, 225, 226, 325, 338, 341, 342 Wohl degradation, 5, 36 Wolff’s reaction, 87
dibenaoate, dibenzyl thioacetal, 36 dibenayl thioacetal, 18 phenylosaaone, 10 3-phosphate1 166 -, 3-O-acetyl-l,2-0-isopropylidene-5-0tOSyl-D-, 182, 198 -, 5-O-acetyl-l,2-0-isopropylidene-3-0x tOSyl-D-, 198 Xanthation, of carbohydrates, 31-32 -, 3-O-benzo y l- 1,2-0-isopropylidene-5X-ray diffraction patterns, 319, 346, 348 0-tOSyl-D-, 159, 182, 198 of meleaitose, 286 -, 5-0-benaoyl- 1,2-0-isopropylidene-3of natural sucrose, 286 O-tOSyl-D-, 198 of “sucrose” from meleaitose, 286 -, 5-O-benaylcarboxy-1,2-0-isopropyliof turanose, 286 dene-3-0-tosyl-~-, 156, 161 Xylan, algal, 348-349 -, 5-O-carbomethoxy-l,2-0-isopropylidiacetate, 349 dene-3-0-tosyl-~-, 160 in red algae, 335 -, a-deoxy-~-,46, 85 methylated, 349 anilide, 97 Xylans, of land plants, 349 4,5-O-isopropylidene acetal, 85 DL-Xylitol, 3-0-acetoxymethyl-5-0synthesis from glycal, 69 acetyl-l-0-mesyl-2,4-O-methylene-, -, 5-deoxy-5-ethylthio-1,2-0-isopropyli148 dene-D-, 178 -, 3-0-acetoxymethyl-5-O-acetyl-2,4-0- -, 5-deoxy-1,2-0-isopropylidene-5methylene-1-0-tosyl-, 148, 160 methylthio-D-, 178 -, 1,3-anhydro-2,4O-methylene-,140 -, 5-deoxy-l,2-0-isopropylidene-3-05-tosylate, 140, 187 ‘tOSyl-D-, 168 -, 3,5-0-benzylidene-2,4-O-methylene- -, di-0-ethylidene-aldehydo-c, 63 1-0-tosyl-, 187 -, 1,2-0-isopropylidene-3-O-methyl-5-0-, chloro-deoxy-2,CO-methylene-di-OtOSyl-D-, 146 tosyl-, 140 -, 1,2-0-isopropylidene-5-O-methyl-3-0-, l-deoxy-2,4:3,5-di-O-methylene-,214 tOSyl-D-, 168 1-cyanothio derivative, 213 -, 1,2-0-isopropylidene-5-0-tosyl-~-, 182 -, bis-l-deoxy-2,4:3,6-di-O-methylene-,-, 2-0-methyl-~-, 349 disulfide, 213 -, 2,3-di-O-methyl-~-, 349 -, 2,3,4,5-di-O-isopropylidene-l-O-, 2,4-di-O-methyl-~-, 349 tosyl-, 187 -, 2,3,Ctri-o-methyl-~-, 335, 339, 349 -, l-O-mesy1-2,4:3,5-di-O-methylene-, D-Xyloside, methyl 3-bromo-3-deoxy-p-, 147 81, 82 -, 2,4:3,5-di-0-methylene-l-0-tosyl-, -, methyl 2,5-di-O-methyl-3-0-tosyl-a-, 187, 213 168 D-Xylofuranose, tosyl derivatives, action a-anomer, 168 of sodium iodide on, 198 D-Xyldose. See D-threo-Pentdose. -, 5-aldehydo-l,2-0-isopropylidene-. n-Xyluronic acid, 1,2-0-isopropylidene-, See D-Xylofuranose, 1,2-0-isopropotassium salt, 236, 238 pylidene-, 5-didehydro derivative. Y -, 1,2-0-isopropylidene-, 128 5-didehydro derivative, 248 Yeast, Lowenbrau, 279 3-tosylate, 156, 160, 161 z 5-tosylate, 128, 146, 159, 178, 182, 198 Xylose, D-, 349 Zemplh-Pacsu method, 70, 99
ERRATA 2 Page 167, reference 14. For “1497” read ‘( 1979.” Page 168, line 4. Change t o read: ‘‘ . . , methyl 2,3-anhydro-4,6-dimethyl-a-~mannopyranoside (11) is hydrolyzed*’ by sodium methoxide to give a mixture of . . . ” Change formula I1 accordingly. VOLUME
3 Read “altro” for “atro.” VOLUME
Page 38, line 10 from bottom.
VOLUME 5 Page 107, line 6. For “cellulose” read “glucose.”
VOLUME6 Page 76, fourth entry in table. The rotation should be -3.8” &B corrected by K. Freudenberg, H. Knauber and F. Cramer, Chern. Ber., 84, 144 (1951). VOLUME
7
Page 301 (two places), second and ninth lines from bottom, and page 325,ninth line. Change 107 to 10-7.
405
ADVANCES IN CARBOHYDRATE CHEMISTRY Volume 1 C. S. HUDSON,The Fischer Cyanohydrin Synthesis and the Configurations of Higher-carbon Sugars and Alcohols.. .................................. 1 NELSONK. RICHTMYER, The Altrose Group of Substances.. . . . . . . . . . . . . . . . . . . 37 EUQENE PACSU, Carbohydrate Orthoesters. ................................ 77 ALBERT L. RAYMOND, Thio- and Seleno-Sugars. , . . of the Cardiac GlycoROBERTC. ELDERFIELD, The Carbohydrate Componentes Comp sides. .. ........................ C. JELLEFF CARRand JOHN C. KRANTZ, JR., Metabolism of the Sugar Alcohols and Their Derivatives.. . ....................................... 175 R. STUART TIPSON, T he Nucleic Acids.. .................... 193 THOMAS JOHN SCHOCH, The Fractionation of Starch. . . ROYL. WHISTLER, Preparation and Properties of Starc R.FORDYCE, Cellulose Esters of Organic Acids., . . . . . . . . . . . . . . . . . . . 309 CHARLES ERNESTANDERSONand LILA SANDS,A Discussion of Methods of Value in 329 Research on Plant Polyuronides. ......................................
Volume 2 .......... C. S. HUDSON, MeIezitose and Turanose.. . . . . . . . . . . . . . . STANLEY PEAT,The Chemistry of Anhy F. SMITH, Analogs of Ascorbic Acid.. . . . . . .............. R. LESPIEAU, Synthesis of Hexitols and Pentitols from Unsaturated Polyhydric Alcohols.. ......................................................... HARRYJ. DEUEL,JR. and MARGARET G. MOREHOUSE, The Interrelation of Carbohydrate and Fat Metabolism. .......... ........... . . . . . . M. STACEY, The Chemistry of Mucopolysaccharides and Mucoproteins. . . . . . . . . TAYLOR H. EVANSand HAROLD HIBBERT,Bacterial Polysaccharides.. . . . . . . . . . E. L. HIRSTand J. K. N. JONES, The Chemistry of Pectic Materials.. . . . . . . . . . EMMAJ. MCDONALD, The Polyfructosans and Difructose Anhydrides.. ........ JOSEPH F. HASKINS,Cellulose Ethers of Industrial Significance.. ..............
79 107
119 161 203 235 253 279
VoIume 8 C. S. HUDSON, Historical Aapects of Emil Fischer’s Fundamental Conventions for ...................... Writing Stereo-Formulas in a Plane. . . E. G. V. PERCIVAL, The Structure and Reac Hydrazone and Osazone Derivatives of the Sugars.. ........................ HEWIIT G. FLETCHER, JR.,The Chemistry and Configuratio BURCKHARDT HELFERICH, Trityl Ethers of Carbohydrates. . ............ LOUISSATTLER, Glutose and the Unfermentable Reducing Molasses.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . JOHN W. GREEN,The Halogen Oxidation of Simple Carbohydrates, Excluding the Action of Periodic Acid.. ................................ JACK COMPTON, The Molecular Constitution of Cellulose. ........... SAMUBL GURIN,Isotopic Tracers in the Study of Carbohydrate Metabolism. ... KARLMYRBHCK, Products of the Enzymic Degradation of Starch and Glycogen. 406
1
79 113
229 252
ADVANCES I N CARBOHYDRATE CHEMISTRY
407
M. STACEY and P. W. KENT,The Polysaccharides of Mycobacterium tuberculosis. 311 R. U. LEMIEUXand M. L. WOLFROM, The Chemistry of Streptomycin.. . . . . . . . 337 Volume 4
IRVING LEVI and CLIFFORDB. PURVES, The Structure and Configuration of Sucrose (Alpha-D-Glucopyranosyl Beta-D-Fructofuranoside). . . . . . . . . . . . . . . H. G. BRAYand M. STACEY, Blood Group Polysacchsrides.. . . . . . . . . . . . . . . . . . C. S. HUDSON, Apiose and the Glycosides of the Parsley Plant.. . . . . . . . . . . . . . . CARLNEUBERQ,Biochemical Reductions a t the Expense of Sugars.. . . . . . . . . . . VENANCIO DEULOFEU, The Acylated Nitriles of Aldonic Acids and Their Degradation . . . . . . . . . . . .......... . ....... ....... ELWINE. HARRIS,Wood Saccharification.. . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . , J. BBESEBEN,The Use of Boric Acid for the Determination of the Configuration of Carbohydrates. , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ROLLAND LOHMAR and R. M. GOEPP,JR., The Hexitols and Some of Their Derivatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . J. K. N. JONES and F. SMITH,Plant Gums and Mucilages.. , . . . . . . . . . . . . . . . . . L. F. WIGGINS,The Utilization of Sucrose.. . . . . . . . . . . . . . . . . . .
1 37 57 75
119 153 189 211 243
Volume 6 HEWITTG. FLETCHER, JR.and NELSONK. RICHTMYER, Applications in the Carbohydrate Field of Reductive Desulfurization by Raney Nickel W. 8. HASSIDand M. DOUDOROFF, Ensymatid Synthesis of Sucros . ........ .....,.......... Disaccharides. . . . . ALFREDGOTTSCHALK, Principles Underlying Enzyme Specificity in the Domain of Carbohydrates.. . ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . Z. I. KERTESZand R. J. MCCOLLOCH, Enzymes Acting on Pectic Substances. . . R. F. NICKERSON, The Relative Crystallinity of Celluloses. . . . . . . . . . . . . . . . . . . G. R. DEANand J. B. GOTTFRIED, The Commercial Production of Crystalline Dextrose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E. J. BOURNE and STANLEY PEAT,The Methyl Ethers of D-Glucose. L. F. WIGGINS,Anhydrides of the Penitols and Hexitols.. . . . . . . . . . . . . . . . . . . . . MARYL. CALDWELL and MILDRED ADAMS,Action of Certain Alpha Amylases. . R o Y L . WHISTLER,Xylan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
49 79 103 127 145 191 229 269
Volume 6
E. L. HIRST,Obituary of Walter Norman Haworth.. . . . . ................. 1 D. J. BELL,The Methyl Ethers of D-Galactose.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 W. L. EVANS, D. D. REYNOLDS and E. A. TALLEY, The Synthesisof Oligosaccharides 27 F. H. NEWTK,The Formation of Furan Compounds from Hexoses.. . . . . . . . . . . 83 RICHARD E. REEVES,Cuprammonium-Glycoside Complexes, . . . . . . . . . . . . . . . . . 108 ROGERW. JEANLOZ and HEWITTG. FLETCHER, JR.,The Chemistry of Ribose.. 135 NELSONK. RICHTMYER, The 2-(Aldo-polyhydroxyalkyl)bensimidazoles.. . . . . . . 175 ELLIOTT P. BARRETT,Trends in the Development of Granular Adsorbents for Sugar Refining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 M. CANTOR,Aconitic Acid, a ByROBERTELLSWORTH MILLERand SIDNEY Product in the Manufacture of Sugar.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 WILLIAMA. BONNER, Friedel-Crafts and Grignard Processes in the Carbohydrate Series , . . . . . . . . . . . . . . . . . . . . , , . . . , , , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251 JOHN JOHN C. SOWDEN, The Nitromethane and 2-Nitroethanol Syntheses. . . . . . . . . . . 291
408
ADVANCES I N CARBOHYDRATE CHEMISTRY
Volume 7
R . A . LAIDLAW and E. G. V . PERCIVAL, The Methyl Ethers of the Aldopentoses and of Rhamnose and Fucose ...................... : . . . . . . . . . . . . . . . . . . 1 R . J . DIMLER.1.6-Anhydrohexofuranoses.a New Class of Hexosans . . . . . . . . . . . 37 C . P. BARRY and JOHN HONEYMAN. Fructose and Its Derivatives . . . . . . . . . . . . . 63 J. V . KARABINOS. Psicose. Sorbose and Tagatose ............................ 99 S. A . BARKER and E . J . BOURNE. Acetals and Ketals of the Tetritols, Pentitols and Hexitols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 BURCKHARDT HELFERICH. The Glycals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210 A . B. FOSTER and M . STACEY. The Chemistry of the 2-Amino Sugars (2-Amino2-Deoxy-Sugars). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247 C. T. GREENWOOD. The Size and Shape of Some Polysaccharide Molecules . . . . . 290
