Volume 15, Fiesers' Reagents for Organic Synthesis

I n(m, :!'f I

Fieserand Fieser's

Reagentsfor OrganicSynthesis VOLUME FIFTEEN

Mary Fieser HarvardUniversity

@

\ TT'ILE Y.INTERSCIENCE PUBLICATION

t,rhnWiley 8r Sons,Inc. \f II'YORI(/ CHICHESTER / BRISBANE / TONONTO/",]NG,'?OII

n t r( n

AJ

.4 ' J 0i ' /\ \ tl

l<'

ADVISORS CaueRoN Blecx DEuEtrRos PERsePHoNe KrtrH DeVntes DRNtnt-ELeeuI\4 MnnceREr Fnul Jnues R. GacP PRrRtclRJ. Lont JoHu K. LYNcH KuRls MecFenntN ANoRew M. MecMIt-lnN JeNNteB. NenENsePc

JouN A. PoRco, JR' CHRtstoPsPnS. Poss JosN A. Rnc,qN Gnec Rr,tcneno H. MnnrlN Setos'tSoRoosg SHeNaseYRrt RoeE,RrF. SreNoee'nr EowRRo M' SUH Scorr VtRctlKplru A. WoPnPel Gne,c Fu, Chairman

Copyright@ 1990by John Wiley & Sons,Inc. in Canada. All rightsreserved.Publishedsimultaneously Reproductionor translationof any part of this work beyondthat permittedby Section107or 108of the 1976United StatesCopyrightAct without the permission of the coyrightowner is unlawful.Requestsfor to permissionor further informationshouldbe addressed Department,John Wiley & Sons,Inc. the Permissions rsBN 0-471-52113-2 ISSN 0271-616X Printedin the United Statesof America 1 09 8 7 6 5

4 3 2 1

PREFACE This volume of Reagentsincludesreportson syntheticusesof reagentspublished for the most part in 1988and during the early monthsof 1989.The manuscript had the benefitof carefulreview by JamesR. Gageand Scott virgil; their advice has been invaluable.In addition, both the galleysand page proofs have been scrutinizedcarefullyby the advisorsfor this volume. Greg Fu drew the formula for the dustcover.Tarek Sammakia(Dr. T) is the photographerfor the pictureof someof the advisors. Meny Flnsen Cambridge, Mass. February 11,1990

CONTENTS

Reagents 1 Author index 373 Subjectindex 395

Acetic anhydride-Pyridine. Dakin-west reaction.t This reactioninvolvesconversionof an c-amino acid to an o-acetylaminoalkyl methyl ketoneby reactionwith an acid anhydrideand a base at 25-135'. when catalyzedby DMAp, the reaction takes place at room

I o . . oPY, ' I AcP, H2NCHCOOH AcNHCHCOGH,+ co. temperature.Secondaryaminoacidsalsocan undergothis reactionaswell asacids that lack an amino group. The reviewdealsmainly with the preparativescope(64 references). ' G . L . B u c h a n aC nh , e mS. o cR . e v . , 1 7 , 9(11 9 8 8 ) . Acetonitrile. Rearrangementof (a-methyldiphenylsilyllalkyl ketones.t These c-silyl ketonesrearrangethermallyto a mixtureof (z)- and (E)-enol silyl ethers.However, rearrangement in acetonitrileresultsin only the (Z)-enolsilylethers(>99: l). These enol silyl ethersare usefulprecursorsto (Z)-lithium enolates.

?

cH3cN z-c'H"-oSiCH3(qH5)' n- crH,rcHlh ) tP. I H' cH3si(c6H5)' (2, > 99:1)

JliSil#",, n -CrH,r.

/,OSi(CH3)3

sAn G. L. Larson, R. Berrios, andJ.A. Prieto,Tetrahedron (19g9). Letters,30,2g3 CH, 2-(Acetoxymethyt)-3-rrimerhytsilytpropene, (CH,),SiCHrla"rOO. (Ll,lt, Improvedpreparation:r

z5g.

Alkylaluminum halides

(

-Cl

cl.siH.cucl. N(qH.\ - -erls

-.SiCl3 [

60%

l) cH'MsBt(81%) z) ronc' Pur (gora)' t

ncz'-,zcl

H.c/-,..c\

clt

r B M. Trost, M. Buch, and M' L' Miller, .I. Org', 53,4887(1988)'

boranewith Acyloxyboranes.Yamamotoet al.t haveusedthe known reactivityof addition Thus carboxyticacidsto activateacrylicacidsfor Diels-Alder reactions. as formulated 1, which of BHT.THFto acrylicacidsat 0'furnishesan acyloxyborane proceedssatisfactorily undergoescycloaddition(equationsI and II). The reaction BLI' "u"n *h"n borane is used in catalytic amounts.A chiral acyloxyborane' asymmetric an preparedfrom a tartaric acid derivative,can serveas a catalystfor Diels-Alder reaction(equationIII).

I l-th

rrb

q'O'too" (D c'z:cHCoo"BH:'rHF,)ro!.":.", I

,lCHt

0I) CHr:C.

'cooH

cH,cHr o . l t l l cH2=c-c=cH2 BH3.rHF\"odC:Crr, ) )_--z 4e% /""""1 CH, CH,

COOH CH,

CHt

".Og-fiT"cooH (ur)CH,:sg6oo el* \,/

\r/

(78Voee'1 Am' Soc' 110'6254(1988)' I K. Furuta,Y. Miwa,K. Iwanaga, andH' Yamamoto,

lry

halides. Alkylaluminum -I4+2|CycloadditionofN.benzytiminesandadiene.Diethylaluminumchlo-

d(l trl .l

(2) with ride is the bestLewis acid for promotingadditionof N-substitutedimines (9,302-303).1 the activateddiene 1

r! E T

Alkylaluminum halides

?'",

4ost(c"")" t cHroA611,

(cH3)3sio\ /ocH3 n'-N\

NR'

il

R,VoCH3

,

I

R = CoHs, R'= Bd

o

h n h

tl

ntva l r l

)

R,,,,.yOCH.

t\

The reactionof the cyclohexylidene ketal 3 of a chiral imine, preparedfrom l-threonine, givesa singleadduct(4), which is convertedby known reactionsinto (5). xylo-daunosamine

, ?H

HNBzI oCH,

cH ,+1 # *cH ,|A| oH

ioocH,

4 (tnEo)

J

,"u"..lrt.p,

5

tr-

rh

H.o*

l l l - - - - -

AsymmetricDiels-Alder reaction.2 The chiral menthyl (S)-3-(2-pyridylsulfinyl)acrylate(1) undergoes[4+2]cycloadditionwith the furan 2 in the presence of (CrHr)rAlClat -20' to give the endo-and ero-adducts3 in the ratio -2: 1, both in about 93Vode. The endo-adduct(3) was convertedby known reactionsto 4, which is openedby lithium hexamethyldisilazide (L2,257)ro the unsaturatedacid tn 56Voyield. Remainingstepsto methyl (-)-triacetoxyshikimate(5) includedebenzylationand acetylation.A similar sequencewith exo-2should provide (+)shikimicacid.

Alkylaluminum halides

COOMen

H-*

ll

COOMen+ exo-2(29Vo)

"?i--*

SOPY (50Vo) endo-3

I

r!J :n!

I

l) PBrs(84%)

I zyuu.1ls*) Ni(45%) 3)RmeY J

es I I I

I ' t

coocH3 Bdo 4

I

l) LiNCNS)2(56%) 2) TMSCI-NaI; AqO-PY (53%)

AO=A/COOCH3

t

t

AcO'\a

)

l

I

OAc 5, o,o-168" alkene 1 with Ari(20)-steroid enereaction'3 The reaction of the Stereoselective diastereoselechigh with (CH)'AlCl proceeds acetylenicaldehydes"u,Jf'"J by centers' chiral tivity (about 95:5) at both OH

I

-2 (>95:<5) (20S,22R) bY be obtained in satisfactorYYield

N-Arylsulfoximines'nTheseimines can chloride followed bY oxidation reactionof an arYlaminewith p-toluenesulfinYl

Alkylcobalt(Ill)bis(dimethylglyoxineanion)pyridine

5

r ) p - c H , c 6 H . s o c r I P l O t il l tl

lrgllE A'NH, I

---.c,H'- s-ct t*#tut I l

lQcr\

I

N

L

- $-c,H, c'H,,

t*-lI

N

\*

(t-butyl hypochlorite)to a sulfoxide.The resultingsulfonimidoylchlorideis then treatedwith CrH,AlCl, in CHrCl, at -78'to provide S-ethylsulfoximinesin 6595Vaoverall yield. rM. M. MidlandandJ. I. Mcloughlin, (1988). Tetrahedron Leners,29.4653 ' T. Takahashi, T. Namiki,Y. Takeuchi, andT. Koizumi,Chem.pharm.8u11.,36,3213 ( I e88). I K. Mikami,T.-P.Loh,andT. Nakai,J.C.S.Chem.Comm..1130 fi988). ' M. Harmata,Tetrahedron Letters,30, 437(19891. Alkyl cobalt(III)bis(dimethylglyoxime anion)pyridine,IR-Co(r'r)(dmgH),py,1]

=i-i.i=;cH, ^u:'i,u4.",

CH, CHt

I

t I \\ith t \ r \ eI C C -

Thesecobaloximes(1) are generatedby reactionof alkyl halideswith in situ generatedcor(dmgH)rpy.They are orangecrystalsthat are relativelystableto air andsilicagel, but on photolysisthey generateR', whichcanbe trappedin generally high yield or which cyclizein the caseof alkenylradicals.' L

SRSCcHs+ + C6H5SSC6H5

a) R = CHr(CH2)e b) R = C41ggr;n

90Vo 92Vo

-Cor(dmgnl,py cH,: g111s1r,)o 4H

R-R

0 0

floclr, SC6H5

r rcld by r\rJJtton

* t:r2

Sc6H5

The R' radicalscan also undergocrosscouplingwith alkenesand with heteroarenes.2

l-Alkynyltriisopropoxytitanium

hv qH.OH -----:--i-------+ 87%

la+

-OTs

f'#''

an.r)\AN

\A*z

l" T

c,nH,,

1:l

H

T

,n=rA r a +( , l l '*)\/

H

E

N l.,*-c,#,,{ rz-1/

N

-ors

-{ rB. P. Branchaud, M. S. Meier,and M. N. Malekzadeh,J.Org.,52,2l2(1987) 2 B. P. Branchaud and Y. L. Choi, ibid.,53,4638(1988).

b D

!r

Alkynyl(phenyl)iodoniumtosylates,RC=CIC6H.'OTs, 14,10-1l. Full detailsfor an improvedmethodfor preparationof thesepolyvalentiodine compoundsare available.'The method is similar to that usedto preparevinylio(L3,151),and yields are 60-89Vo. donium tetrafluoroborates Example: l) C6H,IO, BF3'O(CrHr)Ll

l) BuLi,THF

BuC=CH #

a

BuC=CSi(CH3

2) NaOTs

60-1sqa

BuC=CICuHr.OTs m . p .7 , 7-80"

I

(E)-1,3-Enynes.2These salts couple with vinylcopper reagents to give (E)-1,3-enynes in yieldsof 46-940/o. 1)CuBr.S(CH3)2 2 )c 6 H 5 c = c H BuMgBr

3 )B u c = c l c 6 H 5 ' o r s )

CuH'---r-aH Bu/

-c=cB, (589o)

. ti;-*tn

t t ll ;l

(tlace)

I ' P.J. StangandT. Kitamura, (1988). Org.Sln.,submitted 2ldem.Am. Soc..l(D. 7561(1987).

q d fr

l-Alkynyltriisopropoxytitanium,RECTi(O-r-Pr)...These titanium acetylidesare preparedby reactionof 1-alkyneswith BuLi and ClTi(O-iPr),.

I

r1

Allenylsilanes

7

Cleavageof eporides.r These reagentsreact with unsymmetricalepoxides selectivelyat the more-substituted carbonatom to provide 2-substituted3-butyn1-olsin 33-79Voyield. However,the cleavagerequiresan electron-releasing group at the epoxide,andit takesplacewith partialor completeretentionof configuration. Example: CH2OH

O

^ -, A+ cuHr'

C6H5C=CFi(O-t-pr), (,*7 ^.. lC:CCuu, cuHr'

r N . K r a u s ea n dD . S e e b a c h , B e r . , 1 2113, 1 5( 1 9 8 8 ) .

I )(r(llne

Allene. Photochemical[2+2lcycloaddition to enones.t This reactionhasbeenshown to occur mainly from the less-hindered o-sideof steroidalenones.2 Cycloaddition to the cyclopentenone (1) is also stereoselective, but the stereoselectivity and the yieldsare dependentupon the solvent.The highestyieldsare generallyobtained in an apolar solvent(suchas hexane).

\: I \ llo-

o

"

o

cH"

.X RO

Ro

R = l-Bu

pL

rru

*

l

./\

n

Ro-cH, endolexo

.'t)l-r

l\,Live

CH,

i:'

I",

o tl

R=H

CuH,, CH3CN CuH,, CH3CN

76Vo 58Vo 27Vo 45Vo

49:41 38:62 63:37 62:38

95:5 8 9 :l 1 87:13 90:10

I W. Stensen, J. S. Svendsen, O. Hofer,andL. K. Sydnes, ActaChem.Scand.,B,42,259 ( l e88). : R. Farwaha, P.de Mayo,J. H. Schauble, andy. C. Toong,J. Org.,S0,24s (198s). Allenylsilanes.

lr.lcr are

13+2lAnnelation; azulenes.r A new route to azulenesinvolvesreactionof tropyliumcationswith allenylsilanes, whichgenerates a vinyl cation(a). This cation cyclizesto a cycloheptadienyl cation,which can be convertedto a dihydroazulene by eliminationof H*. However,the presenceof (excess)tropylium cation favors aromatizationto an azulene.Protodesilylation of the allenylsilanecan be effected by use of trimethoxymethylsilane as an acid scavenger.Yields are low (-25Vo)

( SFf,-Alv}'2-l rir€ttylsilyl)borohne

tr) lvY

H-l:s:C.sR''iii'i'ffXl',

f"'

-cH.

iAsin,

@'*. R't

R: = l-BuMez, R'= (cHr3c6H5

L

R

BF.-

' a

I

b with allenylsilanes lackingan alkyl groupat C,, and an alkyl groupat C' is essential for this synthesis. r D . A . B e c k ear n dR . L . D a n h e i s eArm , . S o c . , l f f, 3 8 9( 1 9 8 9 ) .

As dehrdc chcmp &dhtd lnrlcs. trlrr'cr

Allyltrimethylsilane. Conjugate addition to cyclopropanes.t In the presenceof CrH,AlClr, allyltrimethylsilaneundergoesconjugateadditionto cyclopropanes substitutedbygemalkoxycarbonylgroups.

Nacooc2H5 (cH3)ssicHrcH:cHz * -cooc,H, sHrcx.iracooc2Hj e2% " \'/ ,.n./ J-rr, cooc2H5 Review.2 'R. Bambaland R. D. W. Kemmitt,J.C.S.Chem.Comm.,734(1988). ? A. Hosomi,Accts.Chem.Res.,21,200(1988).

(S)-B-Allyl-2-(trimethylsilyl)borolane (1). The borolaneis preparedby kinetic resolutionof (+) B-methoxy-2-trimethylsilylborolane (0.5 equiv.) to give 2 with (1S,2S)-(+)-N-methylpseudoephedrine (+)-3. Reactionof (+)-3 with allylmagnesium bromideprovidesthe borolane

(s)-1.

R P S

.rb

D' rurd Tbc prr

X>#0"

It

BFo'SrR.

+ (R)-2

BocH3t*|-(Prol.u", si(cHJ3 /f\

si(cH3)3 ( + ) - 3( 4 0 : 1 )

t

cH2-cHcH2McBr I

l-4"-at"cH-cHz

\1

'StR,

si(cH3)3 (s)-l

c..e ntial

( i . allylo ^\ qem-

cooc2H5

Asymmetricallylboration of RCHO.t (S)-1 reactswith aliphaticor aryl aldehydesor with a,B-enals to form homoallylicalcoholsin92-977oee and80-92Vo chemicalyield. The chemicaland opticalyieldsare higherthanthoseobtainedwith (14,12),with allylboronatesmodified with tarB-allyldiisopinocamphenylborane trates, or with B-allyltrimethylsilylboronates. The high asymmetricinduction is believedto result from stericefiectsrather than electroniceffects. ' R. P.ShortandS. Masamune, Am. Soc.,1ll, 1892(1989).

Alumina Diels-Alder catalyst.t Attempted purificationof I by chromatographyon neutralAlrO, resultsin an intramolecularDiels-Alder reactionat 20'in 83Voyield. The product (2) is verrucarol,a typical mycotoxicsesquiterpene.

0c:H5 HrC

o

CH, Alror, 20'

€

H,Q

83%

"{: trrmethyl. I t() give h()rolane

10

O'(2'Aminobenzoyl)hydroxylamine

h

^TtHrtl:tlir.

of usedfor protection of phenols'tr-Butvlgroupsareoften involvinga

comm-onlyremovedby a reaction variouspositionsof ut"n"t,-und are effectde-/-butySurprisingly'AlCl' alonecan /-butyl acceptorplus " l-"*l' acid'

r'(

I 1

l a t i o n o f p h e n o l s u t ' o o t t " t p e r a t u r e i n n i t r o m e t h a nthan eorm e t hofy laepara-gtonp' nechloride' that group occursmore readily Removalof an ortho-t-butyl ExamPles: OH (cH3)3c

C(CH3)3

Arcrl ctt.cl", , 25' .

'

1 lqo

2\ t i

\a

l

c(cH3)3

c(cH3)3

t

c(cH3)3

(cH3)3c

I I

I

(cH3)3c

I

rN. LewisandI. Morgan,Syn'Comm''lt' 1783(1988)' Aluminum(Ill) iodide' reagent effectsdeoxygenationof epoxides Deoxygenationof epoxides't Th: which can be isolatedas the 'rans-isomer via an interm"aut" iooJiyOtin (ff':O)' caseof some enect setectivereactionsin the in some cases.This t";;:;;; diepoxides.

AlI3' c,Il6' CH,CN, I hr.

'

10%

All3'8ht

,

9Eo

cH,

I P. Sarmahand N. C. Barua, TetrahedronLeuers,29,

5815(1988)'

O-(2-Aminobenzoyl)hydroxylarnine'

fi'oo*',r,.

\,^NH,

) carvone

O-(2-Aminobenzoyl)hydroxylamine

lcrtitrnof l \ ( \ l \l n g a dc-i-buty;h loride. t/.i-!roup.

11

Preparationfrom isatoicanhydride.r ArtHO-->ArtN.2 Reactionof aromaticaldehydeswith 1 in refluxingethanol containingBF3.O(CrH,),providesthe correspondingnitrile in 78-94% yield. rF. D. Eddy,K. Vaughan J. Chem.,56, 1616(1978). andM. F. G. Stevens, Canad. I P.S. N. ReddyandP.P.Reddy,Syn.Comm.,lE,2179 (1988). (SADP). (S)-(- )-1-Amino-2-(1-methoxy-1.-methylethyl)pyrrolidine

(*\l -.". CH.

( l ) . b . p .6 5 " / 4 . 5 m m .0. D - 1 5 . 4 "

t

HrN

l

ocH3

Hantzsch dihydropyridine synthesis.tThe original Hantzschsynthesisrinvolvescondensation of two equivalents of a keto esterwith an aldehydein the presence of ammonia.In an enantioselective version.rthe chiralityis introduced preparedfrom 1. The by use of a chiral hydrazone(2) of an alkyl acetoacetate anionof 2 is then treatedwith Michaelacceptorsto form adducts(3), which cyclize (4), in 64-727ooverall yield and in 84-98o/oee. to 4-aryl-1,4-dihydropyridines R'OOC\

*'oot). vrr3 #nt-'oo .",4f ,i ciroxides 4/i\ -lsomer 3 ,,i some

cHrAg t

n^rr I

Jii,:!l:.<x1.,

?t"'

64-12% oveterl

O't-c", (s)-2 Ar

C:n one

R'oocv,I\./.cooR2 l l cocH3 A* ..,-, v'r3 I

gCH,

(*)'fCH,.".

Ar t " R'OOCv,i\./COOR'

ilrl CH.

N H

CH,

4

\_J 3

D. Enders,H. Kipphardt,P. Gerdes,L. J. Br€na-Valle.and V. Bhushan,Bull. Soc.Chim. (1988). Bels.,97,691 A. Hantzsch, Ann.,215,1,72(1882);A. Singerand S. M. McElvain,Org. Syn.,Coll. Vol. t . 214 (1943). D. Enders,S. Mtiller, and A. S. Demir, Tetrahedron Letters,29,6437(1988).

Ammonia-Acetic acid

Ammonia-Acetic acid. Tetracyclization.TheHeathcockgrouplhasdescribedaremarkablyshort andefrcientsynthesisoftheskeletonoiDaphniphyllumalkaloids(2)by.reaction o f t h e d i a l d e h y d e l w i t h g a s e o u s a m m o n i a a n d t h e n d i s s o l u t i o n i naaand c e t ithe cacidat precursorto 1' The azadiene 70". The yield is 77Vo,baledon the diol The conversionof a to b is an imine b have both been isolatedand identified' The tetracyclizationmay well be inintramolecularDiels-Alder type reaction' (3)' of aitatoiassuchas DaphnilactoneA volvedin the biosynthesis

("un'

.lr afil

thE

cu afl blt

G

.t

ne I !{

o _ c6H5

C!

o

_

c6H5

c

Ammoniurn formate-Palladium catalvst

a"ut'

' .hort iSctlon lcld at nJ the ) l\ an

f'c in-

l R . B . R u g g e rM , . S o c 'f.1. 0 . 8 7 3(11 9 8 8 ) . i , . M . H a n s e na,n dC . H . H e a t h c o cAkm

Ammonium chloride. The patent literaturehas describedthe prepDiaryl ketimines,ArrC:NH. with ammonia,but arationof (C6H,)rC:NH by direct reactionof benzophenone further.Actually.a numberof diarylketimines thisroutehasnot beeninvestigated canbe obtainedin >95Voyieldby reactionof a diarylketonewith liquid ammonia and a catalyticamountof ammoniumchloridein THF in a sealedtube at 120"(60 bar). I G. Verardo, (19tt8). 1501 S-tn.Comm.,18, P.Strazzolini, andM. Poiana. A. G. Giumanini,

Ammonium formate-Palladium catalyst. reduction,t Aromatic ketonescan be reducedto the corClemmensen-type respondingmethylenecompoundswith ammoniumformateon transferhydrogenation in aceticacid catalyzedby l0o/oPd/C. The reductionis usuallycompletein can be reducedunder these 10-30 minutesat 110'. Halo and nitro substituents carbonylgroupsare reducedto saturatedcarbonyl conditions,and c,B-unsaturated groups.

HCOONH4,

3#5 c6H5cocH3 C6H5COC6H5 (CuHrCH :

i2%+

CH)'CO

c.u5cH2cH3 (C6H ) 2CH2 l*-

(C6H5CHrCHr)rCO

reagenthas been Use of ammoniumformate as a catalytichydrogen-transfer reviewed.2

14

Antimony(V) chloride-Tin(Il) iodide-Chlorotrimethylsilane

RNor--->filt{llr.3This reductioncan be carriedout by transferhydrogenation usingammoniumformate catalyzedby Pd/C.3The reactionproceedsin 60-90Va yield with completeretentionof configuration. OH

nu nx hc

HcooNH4,Pd/c

?t/\-c,H,--HL t i l i I

ll

i'^ r\v2

\./

(synlanti= l:3.2)

(synlani= l:3.2)

,tl I S. Ram and L. D. Spicer,Tetrahedron Letters,29,3741(1988). 2 S. Ram and R. E. Ehrenkaufer, Synthesis,9l(1988). 3 S. Ram and R. E. Ehrenkaufer, ibid.,133 (1986);A. G. M. Barrettand C. D. Spilling' Leuers,29, 5733( 1988). Tetrahedron

Ammonium nitrate-Trifluoroacelic anhydride. This reaction can be effected with the relatively safe combiN-Nitration.t nation of NH.NO. and (CF,CO)'O in nitromethane at 0'. NO,

H

(*)Fo rI#%rl:ro \J

\J

?

A

-\_i?

o"N--_A-..-NOu

n\_-i* ^a --

I S. C. SuriandR. D. Chapman. (1988). Synthesis.743 SbCl., SnI,, Antimony(V) chloride-Tin(Il) iodide-Chlorotrimethylsilane,

clsi(cH.).(1). Cyclization of silyloxy carbonyl compounds,t Five- to seven-membered etherscan be obtainedfrom 1-, D-, and e-silyloxyaldehydesor ketonesby silyl

Cd g

ArenesulfenylisocYanates

!cnrtlon Et 9OVc

15

nucleophilesin the presenceof thesethree reagents,the combinationof which is TrSbClu.The silyl nucleophilecan more efficientthan trityl hexachloroantimonate, or cyanotrimethylsilane. be triethylsilane,allyltrimethylsilane,

o tl

f

-

\

-!jlf*-* + (CrH5)3SiH C6H5C(CHr2CHroSi(cH3)3 a

\OAau",

OSi(CH3)3 vsr\v' r3/3

li

H-i1cur;rcHCuHr+ (cH,)rSicN----'-+ | | cuHr. o^cN cis,28Vo trans,537o 1 K. Homma and T. Mukaiyama, Chem- Letters,259 (1989).

rpilling,

Antimony(V) chloride-Tin(Il) trifluoromethanesulfonate. Michael reactions.t This systempromotesa Michael addition of silyl enol ethersto c,p-unsaturatedthiolesters,which are excellentMichaelacceptors'Trityl saltsare lesseffective,as are Lewis acidsin combinationwith SnClr'

osi(cH3)r

o ll

eH- srcl5's(srfh

l-

crlrsMcH,

t""r'i;tt' 'ar"rt

+ crHrsry-"'

3 c()mbi-

sc2H5 CH, = 87:13) (anilsYn

91 (1988)' Chem.Leaers, M. Tamura,andT. Mukaiyama, S. Kobayashi, ATSNCO. Arenesulfenylisocyanates, isocyanate, (1), unlike the stablepentafluorobenzenesulfenyl Theseisocyanates -ureas' or cannotbe isolated,but can be trappedas arylsulfenylcarbamates Example: c2H5scl+ AgNCo '-'-+ [G,HjSNCO]# I 36% HN(cH3h I

tcnlbered s br silyl

o ll

C6H5SNHCN(CH3)2

C6H5SNHCOOCH3

Azidotrimethylsilane-Aluminumisopropoxide

rT. Nagase, (1988). K. Akama,andS. Ozaki,Chem.Letters,1385 Arene(tricarbonyl)chromiumcomplexes. Nucleophilic addition.t The reaction of (anisole)Cr(CO). (1) with givesalmostexclusivelythe LiC(CH3)rCN,followedby oxidativedecomplexation, meta-adduct,regardlessof the reactiontime, the temperature,or the presenceof HMPT. This regiospecificityis not usual, however. The behavior of (naphtha(cH3)rccN

4"\

l) Lic(cH,),cN._30.

KA

2')r"

>

OCH3

Cr(CO,)

4t\

| rl V\OCH3 (m/o= 97:3)

I

I

{ ul F t .l

(2) is more typical.In the lene)Cr(CO),or of (5,8-dimethoxynaphthalene)Cr(CO). latter case,addition of the samenucleophileresultsin both 1,4,5-and 1,4,6-trisubstitutednaphthalene,(3) and (4). In this casethe ratio of 3:4 dependsupon the temperature,the presenceof HMPT or TMEDA, and the cation (Li or K).

Cr(CO), cH. I

ocH3

f",

MCCN,Tr-rF cHr

-J|'

MCCN, THF

2

4

\

CH"

CH,

q(cH,)rcN

t -

ccN

I

CH, Cr(CO,\ 3

cH3o

Cr(CO), 4

'E. P.Kiindig,V. Desobry, Am. \oc.,111,1804(1989). D. P.Simmons, andE. Wenger, Azidotrimethylsilane-Aluminum isopropoxide. 2-Trimethylsilory azides.t This systemreactsrapidly with epoxidesto give carbon.The productsare trimethylsiloxyazidesby attack at the less-substituted precursorsto azidohydrinsand B-aminoalcohols.

(

Azidotrimethylsilane/Trifl uoromethanesulfonicacid

HOH"C

3{ir}* 1 / + (cH,),siN, ' )v% o

\\ltn lr the rccof r h th a -

ln the .t'-triupon

Kr.

) glve t\ are

"o"'"\-to'*' (cH3)3sid

I M. Emziane, (1988). andD. Sinou,Synthesis,541 P.Lhoste, Azidotrimethylsilane-Trifluoromethanesulfonicacid. Aromatic amination.t Electrophilicaminationof arenescan be effectedwith a reagentpreparedin situftom N.Si(CH.).' tetrachloroaluminate, aminodiazonium yields are obtainedwith aminodiazonium Higher AlCl., and hydrogenchloride. prepared in situ from N.Si(CH.), and F:CSO.H in the triflate, NHTN2.OSO2CF;, are >90Vcfrom arenesthat are not aminoarenes Yields of presenceof the arene. groups. The isomerdistributionis typicalfor deactivatedby electron-withdrawing electrophilicaromaticsubstitutions. G. A. OlahandT. D. Ernst,"/.Ors.,54,1203(1989).

Lr 3 rdSd

cl|"\ Barium ferrate hydrate,BaFeOa'HrO(1)' Preparation:NazFeOo+ Ba(NO.), + 1 (dark purple)' couples Oxidation.t This reagentis similar to barium manganate'It also to dithiols converts yield and aromaticaminesto azo compoundsin moderate

CH

sulfidesin 85-1007aYield. rH.Firouzabadi,D.Mohajer,andM.Entezari-Moghadam'Bull'Chem'Soc'Japan'61' 218s(1988). Barium manganate,8, 21;9, 23;10, 16;,12, 38' Aromatic aldehydescan be oxidizedto the correAICHO - A{OOH.r yields30-92Vo' Ali' spondingacid by this reagent(excess)at25-'40' in CH,CI'; conditions' these under phaticaldehydespolymerize rR. G. Srivastava Syn'Comm''18'2193(1988)' andP.S. Venkataramani, anhydride,(CoHrSeO)rO(1)' Benzeneseleninic oxidationofphenols(|0,23-24).'Theearlierreportofoxidationofphenols oxidation to with 1 mainly to o-quinoneshas been confirmed;recent reports of p.quinoneshasbeenshowntoinvolvecontaminationoflwithbenzeneseleninic for this oxidation'Solventsalsocan u.ii, C.U,SeO,H(2), which is para-selective of choicefor 1, and cHtCl, is the solvents the play a role. THF and benzeneare both 1 and 2 areorthoanhydride, In acetic 2. with Leri ,oluent for para-oxidation in oxidationswith both formed be can selective.In addition,phenylselenoquinones of indole' by addition I and 2, but this reactioncan be inhibited rD.H.R.Barton,J.-P.Finet,andM.Thomas,Tetrahedron'44'6397(1988)'

3 chloride,CrH.SeCl(1). Benzeneseleninyl alkenesto Chlorinationr In combinationwith AlClr, this reagentchlorinates aryl to.provide provide vinyl chloridesand chlorinatesarenes,but not benzene, exchlorinated thlorides. Anisole, diphenyl ether, and N,N-dimethylanilineare of combination Brominationcan be effectedby the clusivelyinthe para-position. I with aluminumbromide. Bull' ChemSoc' andM' Kameyama' I N. Kamigata, H. Matsuyama, T. Satoh,M. Yoshida, (1988) . 2226 449, 61, lapan, 1E

Clf'

Benzenetelluilnicanhydride

Benzenesulfenylchloride. Reaction with silyl keteneacetals;epory alcohols.l C.H.SCIreactswith silYl esters(2) with anti-selectivity.The ketene acetalsto give o-sulfenyl-B-hydroxy (CH"),SiO OSi(CH")" c6Hsscr' '---"'-coHscHr , i t f.*rn-14qo CH^/'4O./"2"s i, !()uples tr,'i'to di-

I

?H ?

t",^ro'/"2"s

-/..:',rrr.61.

.IJ

sc6H5 2 = 6-8:94*92) (sYnlanti lnc corre!1 ,. Ali-

60% LtAltl4 I

oH

pBzl

cH.^

l

"

oH<_.n.&.H,oH " L r r 3 l r

sc6H5 t,l lhengls uJ.rlion to n c . dl c n i n i c t. .rl:tt can l(listhe t,tc orthor *rth both

4

sc6H5

lilf,"l;.J*;r',cH,&osin, t

*

-

-

-

r

6

3

oo+ltcx,),o'rr.I OBzl ^\.4, au Lrr3

-. o

5

Scheme I

(1) can be converted product(2) from 1-ethoxy-1,3-bis(trimethylsilyloxy)butene-l (6)' Scheme (5) or trans-2,3-epoxybutane-1-ol lnto eithers),t?-3,4-epoxybutane-2-ol I. ; . 1 . [ c n e tso r,'ride aryl n n . r t e de x l.rn.rtionof ( jr,'nt.Soc.

(1988)' andS.Thea,Chem.Letters,1683 G. Guanti,L. Banfi,E. Narisano,

o

tl

Benzenetellurinicanhydride' (CoHsTe)zO(1). Oxytellurinylation,t Arenetellurinicanhydridesoxidize 1-alkenesto vic-diicetatesin refluxingaceticacid.The actualreagentis assumedto be ArTe(O)OAc.

n

Benzothiazole

l-alkenesresultsin a cyclicether' p-MethThe reactionwith 1- or D-hydroxylated anhydride(2) is the preferredreagentfor this cyclofunctionoxybenzenetellurinic alization.

.l^l-)r.*

ff*cH,r.ryr-ah V"on

o{

_2fftr bclo,r h;"dror drorla

HCL

Y"/

$"^cH,reAr

227o

454o

rN. X. Hu. Y. Aso, T. Otsubo,and F. Ogura,Tefiahedron Letters,2S'1281(1987)'

,r( \

? trifluoroacetatd,C'H,feOCOCF. (1), is preparedby reactionof Benzenetellurinyl anhydridewith trifluoroaceticanhydride'' benzenetellurinic Allylsilanesn allylamines.t The conversionis effectedwith 1 catalyzedby BF, etherateand is believedto involvean intermediateallyl telluroxide(a), which l,BF3.o(c2H5h l? crcHrcHrcr ) cH3(cH;)5 silcHr), _r,^ _ F._-2.-.-tecrurJ

l

(EfZ = 84:16)

*),,= "* | l-------N-

._\ CHr+R"'Z'\.'\J

a)

,h !*r t CH{I G

N

H

3 Qjqa)

4rq :a ll

\-, 2 ('l l%o)

reactswith arylaminesgenerallywithout rearrangementto give 3, but with alkylamineswith rearrangementto give2. The reactionwith a cyclic amine such as piperidinegivesa mixture of both possibleproductsas shownin the formulation' (1988)' rN. X. Hu, Y. Aso,T. Otsubo,andF. Ogura,Tetrahedron Letters,29,4949 Benzothiazole, N

) ttr

S

afr' td

2-Benzoylthio-3-nitropyridine

fr /)-Methk'lunction-

,- TeAr

2l

a-Hydroxy carbonll compounds.r This heterocycleon metallation (BuLi) at - 78'providesthe 2-lithioderivative(2,I00% yield),whichis stableat temperatures below - 50'. Reaction of the anion with aldehydesor ketonesresultsin 2-(ct(70-90Voyield), which can be convertedinto c-hyhydroxyalkyl)benzothiazoles droxycarbonylcompounds,as shownfor a particularcasein equation(I). I H. Chikashita, (1988). M. Ishibaba, K. Ori, andK. Itoh,Bull.Chem.Soc.Japan,61,3637 CH"

q

I .!cHc,H,

,',G>11 JzH's' G>[:*", # G

N.1-

s 6 " 3

,*r,f"",

rr:.rctionof r t . r l zr e d b y ra).which

o ^'i",*ix''

. 4e% fY\t" c,H.cHJsu ' -J" ,]

\'

i."' s''.HC'H' OH

(f). The reagentis generatedin situby reactionof 2-Benzoylthio-3-nitropyridine 3,3'-dinitro-2,2'-dipyridyldisulfidewith benzoicacid and triphenylphosphinein CH,CI,. a-Glycosylesterc.t The anomericlithium alkoxideof 2,3,4,5-tetra-O-benzyl(2) reactswith 1 to form mainly an a-glycosylester (3, ct/B = o-glucopyranose l6:1). This reactionis generallystronglyc-selective,even with highly hindered

\arrh alkyln( \uch as , r r rL r l a t i o n .

,r,oa-(9-o\ Bzro\_-a;l coc5H5 3 ( 1 6 l: )

n

N'(Benzyloxycarbonyl)'r--serineP'lactone

a-substitutedcarbohydratecarboxylic systemsand is free from epimerizatigll 1f 2-acylthio-3-nitropyridines' acids.It is applicableto other 'A.G.M.BarrettandB'C'B'Bezuidenhoudt'Heterocycles'2E'specialissue'209(1989)' 1' 109;2' 59' Benzyl chloroformate(clco'cH'c6Hs)' group't Reaction of "' i"iy:t"tycarbonylmethyl Protection o7 u'o'it'-niii with 1in acetonitrile giut' u viscousoil' which reacts the uracil (2) with tottain presence glvo overall yield. Alkylation of 3 in the and triethylamin" ,o uffJJ'3- in

o il

HNry

l i l

:il tagl ril

o tl

F 1,f..Tg.,, HN\F ^'J a r,lr9zttsb , l,l 85%

oAN/

oAN/ H

CHTOCOBzI

f 3

q

" -,*"flI,J,y,i;. o ll

RNfr

l l l o4N/ H

t

o F 4, rarc,

CH.OH,25" 84-1m%

**\'

oA*/

CHPCOBzI

o 4 yield' and generallyin almostquantitative (EDA) occurs. of ethyldiisopropylamine racile' (catalvtic hvdrogenation)is equallv ;;;;;i;;;i"; Letters'1381(1988)' Y' Yamada'andS' Ozaki'Chem' rT. Nagase, K. Seike,K' Shiraishi'

p.

(l)'

N-(Benzyloxycarbonyl)-t"serinep'lactone' VEO BocNH 47voyield by reactionof N-(benzyloxycarbonyl)-lThe B-lactoneis obtarnedin in THF It is stable una'oi.ethyl azodicarboxylate serinewith triphenyrpni"s-piin" hydrolyzedby aqueous for sometime; it is rapidly to air at 25" and can be siored base.

I t

Benzyloxymethylenetriphenylphosphorane

cooH PSC#'J., 47q.1

art o\\'lic

HO^r I-

,Jt3.

1989).

l::CIlOnOf t ( : , )n i t r i l e

n

N-Protecteds-amino acids.t A wide variety of nucleophilesattack this lactone at the B-carbonto provide optically pure N-protecteda-amino acids.The (2) is typical.Thisunusualct-amino preparationof N-Boc-B-(pyrazol-1-yl)-r-alanine acid occursin watermelonseeds.

:ra\ence

ii:!I, r*C^" 4 0 - 1 0 % cfxcooH \-N Eli HNBoc , 'S. V. Pansare, (1989). G. Huyer,L. D. Arnold,andJ.C. Vederas. Org.Syn.,submitted (CoH,).P:CHOBzl (f ). Benzyloxymethylenetriphenylphosphorane, (4).t Carbohydratesin which the ring oxygenis Pseudo-a-o-glycopyranose group are known as pseudosugarsand can have useful replacedby a methylene properties. physiological A new methodfor conversionof c-o-glucoseto 4 involves 2. This ketonereacts to the protected5-hydroxycyclohexanone firstrearrangement uith the phosphoraneI to give the benzyloxyvinylether 3, which on Pd-catalyzed

(l',) # Bzro ]oH

(o',,) n,ro\dH

OBzl

H2,

Pdrc,cHioH ---+ 15E

OBzl

\ lcld, and

rj.l (1988).

.

Ho\-/-;El

65:35 OH

CH" \\' arbonYl)-LIr rsstable b\ aqueous

(oBz'/ Bzlo loH OBzl

-&-cH'

"o7-oF__To, =

OH

OH

A

(S)'o'[N-(Benzylproloytamino)benzophenone

product' Surprisingly'the hydrogenation hydrogenationfurnishes4 as the major major product' the (7) as of e gl-u",a pseudo-p-t--pyranose 'I'C'S' andB' Quiclet-Sire' A' S Machado' I D. H. R. Barton,S D' G6ro'J' Cl€ophax' Chem.Comm.,1184(1988)'

o o l l l l (S)-o-[N-(Benzylproloylamino)benzophenone'(

(l)'

)rcurc'H'cc6H5

N

Bzl This reagentand Ni(NO')' react Schifrcomplet with gtycineand Ni(NOt)2' complex2'' with glycinein methanolto form the chiral

8fi8$;

1 + H|CHTCOOH

lillli rccdcs. ]dcr ri ClI. aatacl.

+ Ni(NOr), -;'

for glyThe complex 2 can serveas a substitute S-Hydrory-a'amino acids'r c i n e i n a r e a c t i o n o f a l d e h y d e s o r k e t o n e s t o p r o v i d e t h r e o -(S)-serine p - h y d r o xiny -800-amlno with 2 provides acids.Thus the reacttonof parafo'maldehyde 98Voee' 2 + HCHo'--'r

complex#HocHrcHCooH NH2 (S)- Serine (897o ee)

P r o l i n e s . 2 T h e c o m p l e x 2 u n d e r g o e s b a s e - c a t a l y z e d ( C H 3 oaNdihydroa)Michaelad-!non"r. Reaclionof 2 with acroleinfurnishes unO a,p_enals to dition to (S)-proline' pyt."f"-Z-."rUoxylicacid which is reduced T' V' A' S Batsanov' S' V'.Vitt'-Y^T' Struchkov' rY. N. Belokon'A' G' Bulychev' andV' M' Bakhmutov' I V' Lysova' A L' Ryzhov' M G' V. A. Tsyryapkin' Timofeeva, Belikov,Am. Soc.,lM, 4252(1985) V A' V' A Tsyryapkin' 2Y. N. Belokon,A. G' etlytiJ"' V'e' Pavlov'.EB Fedorova' (1988)' l'C'S'PerkinI' 2075 Sukh.t,"", andV. M' Beiit
1 f,.i; l,'tart.

H rt

t( T>

lFt 9l

tetraciloroiodate Benzyltrimethylammonium en.tllon

2 + CH':Q11CHO

: / (-..s.

t"'o^"

' {-\r"OO" --N' Bzl 73qo NaBH3cN J

flrcooH -N' H

6954o ee) I react

Benzyltrimethylammonium dichloroiodate, Bzl(CH,),NCl,I- (1), yellow needles,m.p. 125-126o.The salt is preparedby reactionof Bzl(CH,),N. Cl in waterwith ICI in CH,C! at 25". The reagenteffectsc-chlorinationof aryl methyl Chlorinationof A{OCHyt ketones. r, clclLcllcl

0) ArcocE

3 t()rgly-(r-amino e rn 80-

ch.rcl adJrhvdro-

r,'r. T. V. ;rJ V. M. lrn. V. A.

r#*

A(ocH,cl + Bzl(cH,),Mcl-+ HCI+I,

S.Kajigaeshi, T. Kakinami, Chem. M. Moriwaki, S.Fujisaki, K. Maeno, andT. Okamoto, Letters, 2709(1987); idem,Synthesis, 545( 1988). Benzyltrimethylammonium tetrachloroiodate,(CH.;.NBzlICl, (l), yellow needles, m . p .1 0 6 - 1 2 5 The salt is preparedby reactionby (CHJ,NBzII with CCI,I in CHrCl, (96% vreld). Side-chain chlorination of alkylarenes.t The reagent effects benzylic chlorrnationof alkylarenesin CCL in the presenceof AIBN. The co-productis , C H r ) r N B z l I C l.z -

C6H5C[LCH3 # (C6H5)3CH ;;-

C6I{5CHCICH3+ di- and richlorinated products (C6HJ3CCI

Letters, S. Kajigaeshi,T. Kakinami,M. Moriwaki, T. Tanaka,and S. Fujisaki, Tetrahedron 2 e . 5 7 8 3( 1 9 8 8 ) .

(R)-( + )-1,1'-Bi'2'2'-naphthol

26

(BINOL)-Dichloro' or dibromodiisopropoxytitaniurn

l)' l,l' -Bi-2,2'-naphthol( BINOL' oi'epoxtdel "'ot)''ion Cleavage ona

The aluminum reagent obtained

by

,"u.,ionotinl-r*i*,oi"it'vr-;id*:llt::tT;[fi iT[:Hil?::fii:fiJl the ate complex(' (3) in 407o in reactionswith epoxides'but andlithium butoxide,;;;; ee.

chlorohydrin .f.fon"*"n" o*iO. into the

rIIS lstr 6r( t 0

rad

-30o' mos most of the ' -^t^A "'i+l' I fnr hoursat -30o' treated with 2 for 5 hours When the keto epoxrde4 is completely (4) is 5' but the recoveredketo epoxide epoxideis cyclizedto the acetal hormone(6)' t"t ii" 'fntr'"ti' of ( )-C1u-juvenile resolved,and can ot *"0

fn,

?

"".4,^A.", OJ' -"3

f"' -2,cH2cr2) i *r,$fcu' "

f"f. cH''t-s^cu'

H (R)-4 (>957oee)

I I

T coocH3 CH, (-) -6 4' 4147(1988)' Tetrahedron' I Y. Naruse, T. Esaki,andH' Yamamolo' (BINOL)-Dichloro' or dibromodiisopropoxytitan' (R)-( + )'1,1''Bi'2,2"naphthol formula (R)-la or u totpt"* 1 with the probable ium (1). These reagent;;; (R)-1.b.

(R)-la, X=Cl (R)-lb' X=Br

Birch reduction

n.rl bY a c t r ri t Y

) \lcl, ys Jl\Vo

Asymmetricglyoralateenereactions,t In the presenceof 4 A molecularsieves (MS), methyl glyoxalateundergoesenantioselective ene reactionswith 1,1-disubwhen by la or 1b. The former is superiorin reactions stitutedalkenes catalyzed involvinga methyl hydrogen,whereasthe latter is superiorin reactionsinvolving a methylenehydrogen.The reactioncanprovideo-hydroxyestersin 70-95Voyield and 85-98Voee.

CH. " I cH,

o II

CH, OH " i l | 4AMs'ctlcq > cH.icHrcHcoocH3 + HCCOOCH,

cH,

a r of the nfJletely l 6) .

(A.",

\

R , 9 5 V oe e R, 837oee

727o 87Vo

la 1b

o

^

o

H

(-\ * "X.oo.",----.-.--------82Vo 89Vo

la lb

coocH3

R, 837oee R , 9 8 7 0e e

andT. Nakai,Am. Soc.,l11,1940(1989). K. Mikami,M. Terada,

Xa", Birch reduction. Reductivealkylation. N-/-Butylnaphthalenesulfonamides can undergoBirch reductivealkylation in acceptableyields. The productsundergopyrolysisto alkvlnaphthalenes.'

mZ--/tr-\

l

l

cH3o^AZ

l

l

,

/*

l)BuLi,NHj,t

,--=;-cH3o$1 . n . , l

l

l

CH,-

$O.mr-r-nu

n.sqa

ory-,titan' R)-la or

,

|

l

l

-SO'NH-I-Bu

^

./\

t i l l "\/Y

cHso

CH, resultsin tetrahydro Birch reductionof phenanthreneor 9-alkylphenanthrenes yield by LilNH. in high but 9,lO-dihydro derivatives are obtained Jerivatives, (equationI). group :eductionof phenanthrenes by a 9-trimethylsilyl substituted yield group quantitative with BuoNFin of L can be removedin The trimethylsilyl

ZE

Bis(acetonitrile)dichloropalladium(II)

houn r:E.l rn€th

R = H, CH:, CzHs

is obtained THF, but if an alkyl halideis present,a trans-9,7}-dialkylphenanthrene (equationII).'

cH.c \tl

c2HsI, BU4NF

(II)

22Vo

78Vo

Reduction of benZocyclobutenes.sBirch reduction of l, available from rnprovidesthe enone2 after hydrolysisof the intermediate. hydroxybenzaldehyde, This enone is a usefulprecursorto the cyclobutanemonoterpenesgrandisol(4) and lineaton(5).

o

rrth ; .\tl r rdrE

(cH3)2culi ) E3% W'

lifsil"',a(a' is%

I-f"A' 4=2

!i.l

+__/

a.--l

v t

2

|

cis-3

9H,

rl}|

OH

CH, 4 I L. GottliebandH. J. E. Loewenthal (1988). Letters,29,4473 , Tetrahedron ' P. W. Rabideau (1988). ibid.,29,3761 andZ. Marcinow, r T. Kametani, T. Toya,K. Ueda,M. Tsubuki,andT. Honda,J-C.S'Perkin1' 2433(1988)' Bis(acetonitrile)dichloropalladium(II). Rearrangementof allylic acetates.t This Pd(II) catalysteffectsrearrangement at 25" in 0.5-2 to (2E,42)-l"acetoxy-2,4-dienes of (1E,42)-3-acetoxy-1,4-dienes

I t l r :r fr ata

(R)-Bis-(l,l'-binaphrhalenyl)2'2'-diselenide 29

hours in 90-96Voyield. This catalyzedrearrangementfavors formation of the (2E,42)-l-acetoxy-2,4-diene. It is the last stepin a synthesisof the acetate(l) of methyl cr-dimorphecolate.


R'

OAc

(R = H, CHr,Bu) of'tained

oAc

oAc

I

CH3 orC(CHJ?"\,/\:,,,

(CH2)4CH3 #

trH"

t"roo C(CH)1)\ZJ I

l lr()m mm.dlate. rilr.ol (4)

1M. M. L. Crilley,B. T. Golding, andC. Pierpoint, "/.C.S. PerkinI,2061(1988). Bis(benzonitrile)dichloropalladium(II). Desulfonylativecouplingof ArSOrCl.t Desulfonylativecouplingof ArSO,Cl with acrylicesterscatalyzedby pplladiumcan proceedin high yield when carried out with solid-liquidphasetransfercatalysts, the bestof which is benzyltrioctylammoniumchloride,BzlOct.NCl. Pd(tr), K2COI

ArSOrCl+ CHr:QflgOOnu ff5

90'.

A1CH:CHCOOBu

(Ar = 1-Naphthyl)

(1989). M. Miura, H. Hashimoto,K. Itoh, and M. Nomura,Tetrahedron Letters,30,975

( R)-Bis-(1,1'-binaphthalenyl) 2,2'-diselenide,

r.r.i( 1988)

r.tngcment ' rn 0.5-2

Methoxyselenenylationof alkenes,t This reaction can be effectedby reaction of 1 with Br, in CH.CI, to form a red solid that is consideredto be a selenenyl bromide.This intermediatereactswith an alkenein CHrOH to give a methoxy.clenenylated alkene.The reactionwith styrenegivesonly the Markovnikovproduct in a yield of 49% and 49o/ode.

Bis(cyclooctadiene)nickel(0)

I

l) Br2, CH2CI2 2 ) C ". H < " C H= C H , , C H -I O H

>

o?

Th! cloadd the erl the str suitabl

'"tYtn' ocH3

@

(497o de)

I S. TomodaandM. Iwaoka,Chem.Lerlers,1895(1988)'

\( perchlorate, perchlorate(Iodonium di-sy'?x-collidine) Bis(sym-collidine)iodine(I) *I(C8H"N)' ClO. (1)' 10' 212-21'3. Iodocyclization.t This reagentconvertsvariousunsaturatedalcoholsinto ethers and unsaturatedcarboxylicacidsinto lactones.It is particularlyusefulfor synthesis from allylic alcoholsand of 2-(1-iodomethyl)oxetanes of 2-(1-iodomethyl)oxiranes from homoallylicalcohols.

l+L cH":cHCHoH ' I CH,

cH.-"c*2t

-+ CHr:6611r6HrOH "' " [?

|

o

+

A

76t24 cu,AcH,r

I R. D. Evans, J. W. Magee, and J. H. Schauble, Synthesis,862 (1988)'

Ni(COD),. Bis(cyclooctadiene)nickel(O)' reactionof an aldehyde and -pyrones. The Ni(0)-catalyzed Bicyctico.-pyrans in results bicyclica-pyrans.'This 1,7-octadiyne with a terminallydialkyl-substituted reactionis highly dependenton the lengthof the chainconnectingthe triple bonds and on the presenceof the terminalsubstituents. CH" N(o),(,-Buhp THF

-+ CflTCHO ,*' c=ccH3

ffi t

I

i

w 9rH'

c=cc2H5 c=cc2H5

YO

R=cF

^,,,

CH,

C=CCH3

to form rcd crxr

coo

TCH,I

CH,

AU &nsarr

l CH,

CuHt

A

Bis(cyclooctadiene)nickel(0)

31

This nickel(O)catalystin combinationwith a trialkylphosphinecatalyzesa cycloadditionof 1,6- and 1,7-diynes(1) and CO, to providebicycloc-pyrones(2) at the expenseof dimerizationof 1 to 3.' Cycloadditionto 2 is highly dependenton is the most the structure of the phosphine.In general,tricyclohexylphosphine the a-pyrone' to for cyclization phosphine suitable

N(coDDb, a't2-O'

//-c=c-R

+CO"----:r---+l

|

\-.:"-* l r . r t c.

|

,^rA"(cHJ4c=cR

,

+ |

W"

r

R

nlhcsis tcl itnes

I

R

3 (0-45Eo)

2 (50-857o) ) L-thers

ll

vfR

(1), availableby conAltylnickethomoenolates.32-Vinyl-1,3-dioxolan-4-ones reactwith Ni(coD)2 acids. (S)-2-hydroxyalkanoic densationof acroleinwith (R)- or forms the dark ClSi(CH,). with to form an allylnickelcomplexwhich on reaction undergoes complex this polar solvent red complex2. In the presenceof light and a R_* OH | COOH

+ cH':611911o '----)

(R = cyclohexyl)

R=*zo\r-CH:CHz \ /

)-o o

liil!,'8ill,. cv-o'.-26---;;E:o .r"t TMSO/

I

li.lchYde rn. This rlr bonds

2+RX

nv' DMF

> 72-82Eo

"r-,,o-a

J,ol, es66s,s11rp

R C:O TMSO/ 3 (E/z--9:1)

""Jff,'Fl,l*",, cuH':a","ocH'

4 (94Vo da)

32

Bis(cyclopentadienyl)diphenyltitanium

equivalkylationto provide(E)-enolethers(3)' and theseserveas a homoenolate reaction aldol enantioselective undergoes also atent of a new type. The complex with acetals. 13+2|Cyctoadditionofmethylenecyclopropaneswith2-cyclopentenone(cf.13' in the presenceofthis reactwith 2-cyclopentenone 35).0 Methylenecyclopropanes (Lewis acid)to form 6-methtriethylborane and Ni(0) catalyst,triphenylphosphine 3.0loctane-2-ones. ylenebicyclo[3.

o

("

a

+ cis-l

_An*?ll-Il',f,r,,\a 6E%

cHr(ct|:)

L. Summenl :T. Nakano ao Bis(dibenzyl

Y-(*tt,tt

\J

A

bination with r speciesis prd

R = n-CsHrr trans-l

CH. )\'

/ \

o Jt .()?(

q \-\ t %

.m on

r

)-cH,

-CH,

Of:f'1fr

.rt"'

CHt (exo)

,,;',

R'\11

H t

Am' Soc''f10' 8570(1988)' rT. Tsuda, andT' Saegusa, T. Kiyoi,T. Miyane, Org''53' 3140(1988)' 2T. Tsuda, andT' Saegusa'J' R. Sumiya, S. Morikawa, 6273(1988)' t D. J. KryrunandP.B. Mackenzie, Am' Soc',110' 4539(1988)' ' f. ning.i andB. Schiifer Letters,2g' , Tetrahedron Bis(cyclopentadienyl)dihydridozirconium,Cp2ZrH.' 14' 37' Meerwein-Ponndor!-Verleyreductions.ZirconoceneorhafnocenecancatThis method is useful alyze reductionof carbonylcompoundswith isopropanol' and of a'p-enones ketones hydroxy to aldehydes keto for preferentialreductionof -enals to allYlicalcohols.' or

o

Cross-oor meth.v"lceph t U l . 5 6 ) .A r r enhancesthe

f*,

l

I

\ Fanna.S. I , 1988).

eBb{drpfcrgl heparatro

o

il cH"A_cHo

-- co;7tL Jt cH,oH + (cHr)rcHoH-'*"* cHr\,zunzun

cH,z\..-cHo

+ (cH,)rcHoH;7

ltC,tLpil I

o cH,^,-cH'oH

(1988)' rT. Nakano, S. Umano,Y. Kino,Y. Ishii,andM' Ogawa'J'Org''53' 3752 Bis(cyclopentadienyl)diphenyltitanium,CpzTi(CuH')'' Preparation'' in comilydiosilylatioln of-ketones., Diphenylsilane or methylphenylsilane

Ocorytan rtcnated strt :Ddc (DTBP -ccncc of a tr'JrrXtlr latrO

p-Bis(diphenylhydrosilyl)benzene

noiJte equlvrhitrl reaction

znone (cf..13, €!cnce of this form 6-meth-

33

binationwith diphenyltitanocene canconvertketonesinto alkoxysilanes. The active speciesis probablya titanium hydridecomplex,possibly(Cp,TiH)rH. osiH(c6H5)' + (C6H5)2SiH, + CprTi(Cu CH3(CHr)4COCH3 Hr),

#

C4(CH2)4CHCH3

' L . S u m m e rRs ., H . U l o t h a , n dA . H o l m e s , A mS. o c . , 7 7 , 3 6(0149 5 5 ) . : T. NakanoandY. Nagai,Chem.Letters,48l(1988). Pd(dba)r-( Bis(dibenzylideneacetone)palladium(0)-Tri(2.furyl)phosphine, O

CI l

) \

CH .

?.r,' ir

Cross-coupling of allyl halides with unsaturated tin reagents.t 3-Chloro(2) are inert to vinyltin reagentsunder Stille'soriginal conditions methylcephems (12,56). A study of varioussolventsand ligandsfinds that tri(2-furyl)phosphine enhancesthe rate and leadsto generallygood yieldsfor this coupling.

R'NH \-/-\ l

s l

l

o**?c^r, t

N\

'

/-\ cH:

'snBu,

18%

^

COOR" 3

r:: ,1988)

r i . r l a n et n c o m -

Tetrahedron Letters, 29, 5739

pBis(diphenylhydrosilyl)benzene (1). Preoaration:

2(c6Hi),siH + Mg+ rr+s. cl

)H

on*t'Y

COOR'

V. Farina,S. R. Baker,D. A. Benigni,and C. Sapino,Jr ( 1988).

H:oH

*'*)-]-tJ"')

I, THF. 65'

)

[\-cne can catcthrrdis useful I ot a.B-enones

\,

"s5,a,",,,o$si(c6Hi)2 l, m.p.108.5o

Deoxygenationof ROH.t Acetates,primary,secondary,or tertiary,aredeoxrgenatedwhen heatedwith 1 in the presenceof a radicalinitiator, di-t-butylper.rride (DTBP). Yields using (C6H5).SiHin place of 1 are definitelylower. The :rresenceof a double bond in the substratecan lower yields owing possiblyto rvdrosilylation.

ftr.

v

llJ.l

(R)- and (S)-2,2'-Bis(diphenylphosphine)-1'1'-bin&phthyl

OAc

(2S,3S)-(- Fl I, DTBP

I

c6H5cHrcH(cE),

c6H5cHrc(cH )' +>

r H Sano,T. Takeda,and T. Migita, Chem.Letters,119(1988).

(1, BINAP) (R)- and (S)-2,2'-Bis(diphenylphosphine)-L,l"binaphthyl Asymmetic hydrogenationof allylic alcohols (14, 39-40).' Mammalian dolwhich are involved in glycoprotein ichols (2) are terminal dihydropolyisoprenols synthesis.They contain one terminal chiral primary allylic alcohol group. The polyprenols3 presentin plantscorrespondto dolicholsexceptthat they lack the terminaldoublebondconsideredto be (Z). They canbe obtainedby hydrogenation and (S)-1, which affectsonly of 2 catalyzedby (bistrifluoroacetate)ruthenium(Il) the terminal double bond to provide (S)-3in >95Vo ee. CH"

CHrr

Asymrsc alkaloidscan alyzedbv Pd(

,,..,-r'*f;1"r."*,

l--

--i-cHCHroH--=;;: (CHr)rC: CH'(CH,C:CHr) "CH; (Z) 2 . n = 1 3 -1 5G + Z )

9H,

9H,

t i (CHr)rC: CF!(CH,C: CHr)"CH2CHCFLCH2OH (S)-3 (>957o ee) Asymmenichydroboration.2 Hydroborationof alkeneswith catecholborane catalyzedby Rh(COD)CI'2BINAP or [Rh(COD)CI],'2DIOP and followedby oxidation providesoptically activealcoholsin 20-157oee; Rh-BINAP systemsare than Rh-DIOP systems. somewhatmore enantioselective

*>-F,

--------r . 2DroP,-25' tRh(coD)cll -25" tRh(coD)cll.28INAP, C"H, |

cnf\cu,

--------t

l_-\__,_l

DIPAMP. and most efiective practicalroutc J. P.Generar

llJ-Bb(@.r riftorooellr Preparatio

L R , 2 R , 5 7 7 oe e lR,2R,64Vo ee

C^H, I' .\-oH

cH3

R , 2 7 7 oe e I B. Imperiali and J. W. Zimmerman,Tetrahedron Letters,29,5343(1988) 2 K. Burgessand M. J. Ohlmeyer,J. Or9.,53,5178(1988).

/ \ (C.tLLP" . \

ll,2rBis(diphenylphosphono)ethanelcyclopentadienyl(iodomethane)ruthenium triflate

(2S,3S)-(- )-Bis(diphenylphosphino)butane [(S,S)-Chiraphos],

(c6H5)fdrFdrnlcuttr;, (L). Supplier: Strem. I H"C

n r . r i i a nd o l lr ctrprotein g r ( ) u p .T h e rcr i.rck the lr,rgenatton .rtlects onlY

I CH"

Asymmetric cyclization to tricyclic ergolines.t The ergoline systemof ergot alkaloidscan be obtainedin fairly high enantioselectivity by cyclizationof 2 catalyzedby Pd(0) complexedwith a chiral ligand and a base.The ligandsBINAP, AcOCH' NO' I l -

\ t\

CH. NO' l " t i

ht

t

t

z \ - . { ' .\)l g lo*" ;',A 'l t 4 t I ll \-AN'

ll ) \,4:,r'

H

H

2 + (-)-f, DME,KF 287o + (-)-1, TIIF,K2CO3 62Vo

rr,

3 'll%o er 667oee

{cH:cH2oH

lcihtrlborane l('\\cd bY ox) .\:ttlfflS

&f€

DIPAMP, and Norphosprovide3 with someenantioselectivity (26-47Voee). The most effectiveligand is I in combinationwith KF, but the yield is low. The best practicalroute to opticallyactive3 is the useof I as ligandand K,CO. as base. J. P.GenetandS. Grisoni,Tetahedron (1988). Letters,29,4543

[ 1,2-Bis(diphenylphosphino)ethane]cyclopentadienyl(iodomethane)ruthenium nifluoromethanesulfonate, Cp(dppe)Ru(ICH1)triflate (l). Preoaration:

cF3s03cH3 CHrClr ----€ ,Ru. (cuHr)rP_1_)P(C6H5)285Ca I I )

o -f-

Ru (cuH,),P\_l)P(C6H5)2 cF3so3ICH3 I

36

Bis(1,1,1,3J,3'hexefluoro'2-propyl)hydrogenphosphite

enaminesand enolates as well as C-Methylation.r This triflate methylates other nucleoPhiles.

(*)

cH,CrrO

A

*r$

r\,u'*z \_/

\-/

t

\,/

Dcd xdcs. rhE parrcl cont

o

oLi ,\

l.6Bi(-

*1#

t

€nsrtuzct!

,\.cu,*z

\-2

o \

7' 1891(1988)' Organometallics' rR. J. Kulawiec andR' H Crabtree'

RCOS

r

o

hydrogenphosphite(1)' Bis(1,1,1,3,3,3'hexafluoro'2-propyl) PreParation:

}r Ot.dr

ff

l - ? ltY,l:;l':il:tJ cH1cL''" ) rcr,+(GH,),COH lCt,$"J

!,+lti{2

deoxyusefulfor preparationof protected Phosphonylation'' This reagentis for synthesisof phosphonates(2)' which can be used ribonucleoside-3-hydrogen deoxyribonucleotides'

:ca{cnl l. ROE artcnrtc 'C,H.r,C n o-ard : \rrb,

DMTrO

n.o,,DMrro Jutt llla,?,,,*,

Hfl

80-90%

7

Lerters'1675(1988) I H. Takaku, S. Yamakage,O Sakatsume,and M. Ohtsuki, Chem'

.ITL' !Lpoe 9: o{ ti r\. BrCl, iI u l{' fcr! rccr H grtu"

Bismuth(lII) chloride F\l.rlc\ aS well aS

1,6-Bis(dimethylamino)pyrene,

Decarboxylation.t This reactioncan be carried out via N-acyloxyphthalimides,which undergolossof CO, when irradiated(350-450nm) in aqueousisopropanolcontainingt-BuSH (proton donor) and 1, which servesas a sensitizer.other sensitizers are lessuseful.

o

RCOJ.{

\--.,+. .^r-{/

RH

+ (r-BuS),

Q2-98qo)

?t$Vo)

II

o

( 169 8 8 ) . K . O k a d aK, . O k a m o t oa,n dM . O d a A , m .S o c . , 1 f 0 , 8 7 3

o .cr{()i.PH . rnm

l:

'-*fi "'o , l. + r-BuSH

..r nrotected deoxyl\i\i l()r synthesis of

2.{-Bis(p-methoxyphenyl)-1,3-dithiaphosphetane-2,4-disulfide (Lawesson's :eagent). ROH --->RSH.t This transformationcan be effectedwith this reagent(1) in :noderateto high yield. The yield is quantitativein the caseof triphenylmethanol C-H,)3COH],but somedehydrationis observedwith tertiary alcoholspossessing :n a-methylor c-benzylgroup. (1989). I Nishio, J.C.S.Chem.Comm.,205

o

.'..y'" r -o

/

Ft\{(crH5)3

: . : : , ' r ' .1 6 7 5( 1 9 8 8 ) '

Bbmuth(III) chloride,BiCl,. Aldol reaction.t Silyl enol ethersreact with aldehydesat 25oto give aldols : the presence of BiCl, (5 mole %).The classical version(Mukaiyama,6,590i.lt of this reactionusuallyrequiresa full equivalentof TiCloas the promotor. lhe BiCl. versionpermitsuseof ketonesas well as aldehydesin reactionscarried ui at 25o,but a longer time is requiredand yieldsare only moderate(20-65Vo). !i.rh versionsshow only slight diastereoselectivity. iJ Ohki,M. Wada,andK. Akiba,Tetahedron (1988). Leuers,29,4719

33

Bis(pyridine)iodine(I)tetrlnuoroborrle

Bis(1,3-propanediamino)copper(Il)chloride' H, H" /-N.. ' c,.u ','N--\

(

\-1.r'' A,

t'NJ

.,

c

l]cntc ) 2cr (1).

I ntram oI ecuI ar cycI i zlt molecular cyclization of b pounds. It also effectscydi

H2

and oxiOxidative coupling of hydroquinones't Oxygen can effect coupling presenceof this dation of hydroquinonesto biquinonesin 50-75Voyield in the complex.

oH | ^ _ -

ll'i:.lyLi l2)cHru | I|

7,-

l=/n.,

o.

,^

r[-f""''"'3ij,!oo", 't5% "{}<]" \:,/

(/

'\2

\ CH':CH(t

897(1988)' Synthesis' IS. M. Paraskevas, andG' Vassilara, D. Konstantinidis' Bis(pyridine)iodine(I) tetrafluoroborate' I(py),BFo' The compoundis obtainedby reactionof iodine and pyridinewith HgO'HBFr supportedon silica. |,I-Diodo-|-alkenes.|Thisreagent(1)incombinationwithawidevarietyof nucleophilesreactswith f-iodoalkynesto afford2-substituted1,1-diiodo-1-alkenes (2) in 50-85Voyield. The productscan be convertedto a variety of alkenesby reactionof both the iodine atoms.:

rHr" c6H5c=cl+ r + (cHs)rcHoHffi ''

F

rr

l) rac-Bul-i

' J. Barluenga, J. M. Gonzal 3 1 9( 1 9 8 s ) . : J. Barluenga, M. A. RodrU 'J. Barluenga, J. M. Gonza ls46(1988).

Bis(tributyltin) oxide, (Bu, Cleavageof estcrs.t ? of NL or Ne-adenineand o is a problem in the caseof the ring. The pivaloyloxlr ffiVo yield by bis(tribut-vlti rin intermediate.This mal thosecontainingpeptidch E. G. MataandO. A. Mc

]l-])a:tt,2#

(cHJrcHo2

cuHr-^_../cHOHCH3 (clL)rcHol--"-,

Bb( tributyltin) oxideS&c RCHYX---> RCHOII.. sro reagentsto give the cq Clotimum ratios for this rc

Bis(tributyltin) oxide-Silver nitrate

2llffi;?l''' #,.",,,1"T>.:.<;: L",,,;itc:cL,J Intramolecular cyclization of homoallylbenzenes.. This reagenteffectsintramolecular cyclizationof homoallylbenzenes to iodine-substitutedbicyclic compounds.It also effectscyclizationof 1,5-dienesto iodocyclohexenes. coupling and oxiB rresence of this



V*"/E\A/, ".-ra\ l l \,,/

FO

l

4/-

l _ - "ol l l \-cuH, \-A--

)

J;tii'-11%, (-\, cHr:s111sn)rcH:cH, 10% \J

\ I J . B a r l u e n g a , J . M . Gonzalez,P. J. Campos,and G. Asensio,Angew.Chem.Int. Ed.,A,

v - ."\s).

nc \\rth HgO'HBF4 rth.r$ide varietyof . l-Juodo-1-alkenes n.!\ of alkenesbY

: ) Jrc-BuLi :) CHTCHo

Cl- --- -='

CHOHCH" ,C-l

3 1 9( 1 e 8 5 ) . r J. Barluenga, M. A. Rodriguez, P. J. Campos,andG. AsensioAm. Soc.,1f0,5567(1988). ' J . B a r l u e n g aJ ,. M . Gonzalez,P. J. Campos,and G. Asensio,Angew.Chem.Int. Ed.,27, r546(1988).

Bis(tributyltin)oxide, (Bu.Sn),O. Cleavageof esterc.t Pivaloyloxymethyl estershave been usedfor protection of NL or Ne-adenineand of B-lactams,includingpenicillanicacids.Deprotection is a problem in the caseof B-lactamderivativesbecauseof the ready cleavageof the ring. The pivaloyloxymethylestersof penicillanicacidscan be cleavedin 5560Voyield by bis(tributyltin)oxide in ether at 25', probablyby way of an organic tin intermediate.This method is also suitablefor cleavageof simpleesters,even thosecontainingpeptidebonds. E. G. MataandO. A. Mascaretti, (1988). Tetrahedron Letters,29,6893 Bis(hibutyltin)oxide-Silvernitrate, (Bu,Sn),O-AgNO,. RCHrX '-->RCHzOH.T Primary alkyl bromidesor iodides react with these :'*o reagentsto give the corresponding primaryalcoholsin moderateto high yield. C)ptimumratiosfor this reactionare (Bu,Sn),O/Ag/halide= 2.2:l.l: 1.0. Alkyl

40

1,1-Bis(trimethylsilyl)ethylene

chloridescan be precursorsif first treatedwith NaI (3 equiv.).The reactionis not usefulin the caseof secondaryhalidesbecauseof elimination' sio2 q

AgNO3 @u3Sn)2O,

RCH2X

ot'rp'zo-so't [RCHroSnBur)#;

RcHroH

rM. GingrasandT. H. Chan,Tetahedron 279(1989)' Letters,30,

'M. Kira,T. Hioo 6939(1988).

Bis(trimelhyklyll Electophilk reagentsaffords t actionwith vinvl (

C6F,I[OCOCF.],(1)' [Bis(trifluoroacetoxy)iodo]pentafluorobenzene, This hypervalentiodine reagentis preparedby reactionof cuF I with trifluoroaceticanhydride. oxidative cleavageof alkynes.t This reagent(3 equiv.) cleaves1-alkynesto acidsin 55-80% yield. norcarboxylic the org.,53'6124(1988). lR. M. Moriarty, andI. Prakash,J, A' K. Awasthi, R. Penmasta, (1). 1.,1-Bis(trimethylsilyl)ethylene of Li in THF with 1 leadsto the l,4-dianion Reaction Peterconreactions.t in 96Voyield. This dianionreactswith (2\ of 1,1,4,4-tetrakis(trimethylsilyl)butane canbe convertedto 4 by brominationwhich 3, 1,S-diene to form paraformaldehyde bromodesilylation.

[(cH,),si]rc:cH, #I*

Oxidation ot br bis(trimethyls rncreasedby use r

q

[(cH3)3si]racH2cHrclsi(cH3)31' , ,ro | """o

{

(cH3)3si

l) Br2

l

J# CHr: 611CS,CH'CH:CH' l

l

Br

Br

4

4

%

si(cHJ3 l

CHz:CCHzCH,C:CH, 3

4 results The dianion2 can be alkylatedas expected.Reactionwith dihalosilanes (equationI). in silacyclopentanes

This transform fonvloxaziridine(i ri accompaniedb1 a-Ily&or-t a theseacidsor anit Frund in 30-0q ;rclohexanoneor

L Camici.P.Dcrd F A. Davis.G. Sr \l Pohmakotrand

,ISi(cH:)r]z

( I )2 + H r S i C l r # I

SiH.

Y 'Isi(cH3)3]2

lir{Eirnctbylflyl)

'cH,),siol: cFs .4rcmartcly/

Bis(trimethylsilyl)peroxide/Trifluoromethanesulfonicacid 4l l€ reaction is not

toH

'rlI l-F.l with trifluo-

'M. Kira, T. Hino, Y. Kubota, N. Matsuyama,and H. Sakurai,Tetrahedron Leuers,29, 6939(1988).

Bis(trimethylsilyl)peroxide,[(CH,)3SiOlr,l1-, 67; 12, 63. Electrophilic hydrorylation r Reaction of this peroxide (1) with Grignard reagentsaffordsthe correspondingsilyloxyderivativesin 70-90Voyield. The reactionwith vinyl Grignardreagentsresultsin silyl enol ethersor c-silyloxyketones. OSi(CH")" -"

MgBr |

RC:CH,

j*

C6H5CHO,

|

ricr{

nC:Cu.

57%

o o H

i l l

> RCCH2CHC6H5

to :are: 1-alkynes ; s - l . 6 1 2(41 9 8 8 ) .

t., lhe 1,4-dianion trrntonreactswith r{ f'r bromination-

Aa"st',

aV

(/

(-,1-osi(cH3)3

-;

oxidation of vinyllithiums.2 vinyllithiums are oxidizedto silyl enol ethers bv bis(trimethylsilyl)peroxide(1) with retentionof configuration.yields can be rncreased by use of bis(t-butyldimethylsilyl) peroxide(2). l) rBuli

H,,,1:

(E)

(z) (z) Sr CH), {.C:CHu I

Jrh.,Iosilanesresults

z)r*z

coHr\,r'Bt I I 2

,

llvo l87a 35Vo

cu4AroSiMe'R (8, 100%) (2, tw%) (2, tn%)

This transformationcan be carried out by oxidation with ( + )-camphorylsul:,'nvloxaziridine(13, 64-65) followed by trappingwith ClSi(CH.).,but this route . accompanied by partial inversionof geometry. a-Hydroxy carborylic acids or amides.! Reaction of the dianion (LDA) of ':cse acidsor anionsof amideswith I providesthe corresponding o.-hydroxycom:uund in 30-60% yield. The reagent fails to hydroxylate the lithium anion ot :5ctohexanoneor of e\t phenrj\acetate. (1988). L. Camici, P.Dembech, A. Ricci,G. Seconi, andM. Taddei, Tetrahedron,44,4197 :F. A. Davis,G. SankarLal, andJ. tVei,Tetrahedron (1988). Letters,29,4269 l{. Pohmakotr andC. Winotai, (1988). Syn.Comm.,18,2141 Bis(trimethylsilyl) peroxide/Trifluoromethanesulfonicacid, cH,)rsiolr/cF3SO.H. Aromatic hydroxylationt This reaction can be effectedin moderateyield

A

3!'-Bis(triphenytsilyl)binaphthol-Trimethylaluminum

s(cJrr\

(11' 256)' A more effective with30VoHrO, in combinationwith HF/BF3 etherate activatedby triflic acid' and convenientreagentis bis(trimethylsilyl)peroxide

l>^

(1989)' I G. A. OlahandT. D. Ernst,"/' Org'' 54,1204 Bis(trimethylsilyl)selenide,[(CH)3Si],Se(1)'' The reactionof diunI ntramolecular v + 2lcyiloaddition of selenaldehydes.2 saturatedaldehydessuchas2withl.inthepresenceofacatalyticamountofBuLi givesselenaldetryaes(a)whichundergointramolecularDiels_Alderreactionsto 3 in modestyield' give selenabicyclics

(-'ln*-K."'qCH, 3 = 65:35) (cisltans

2,n=3

J' Orq',47'1354(1982)' rPreparation: M. R. Detty,andM. D' Seidler, (1988)' ' S. MuraiandN. Sonoda Letters,29,6965 Tetrahedron ,

S(CJT\ (R)-r (l) C6F5CHO +

clq

(lI) CI3CCHO+ Ctq:q

' K. Maruoka.Y. Hoshino.T. Shirrd ( 1988).

Blue tetrazolium,L, 61. Oxidation of stcroid enou,.l zolium (1) in an alkalinemediumI Other examples:

R 1,2-Bis(trimethylstannyl)'1'alkenes, lCUr;rSn>C:CHSn(CHr\

4

(1)'

by addition of The reagentis obtained, solely or mainly, as the (Z)-isomer benzylic, allylic, with couples It Pd(0). by hexamethylditinto 1-alkynescatalyzed of replacement by selectively BzlPdCl[P(CuH,)J, or aryl halidesin the p."r"n." of on halogen by replaced also is C, at group the C,-Sn(CHr),group. The stannyl reactionot (Z\-l with NIS or NBS.'

CH.'Y- s

I CrH
Ol{

o' cr-CH, F-CH,

65% 27%

969(1989)' rT. N. Mitchell,K. Kwetkat,D. Rutschow, andU. Schneider,Tetrahedron,45'

l.C.S.Chem.Comm..f J. Jasiczak, 47 3,3'-Bis(triphenylsilyl)binaphthol-Trimethylalurninum(14' 46' )' Enereaction.Theenereactionofaldehydeswithalkenescatalyzedby(R)enan1 and 4-A molecular sievescan provide bomoailiic alcohols with marked II). I and (equations tioselectivity

t.Borabicyclo[3.3.1lnonrne (]BB Enamines -+ alkencs.t Hy&t toneswith 9-BBN followed bv mc{

9-Borabicyclo[3.3,1lnonene

s(c6H5)'

ir:i: , ll. 156).A more effective rr.t. .,rlrvatedbY triflic acid.

]dchrdes.2 The reactionof diunl{c : .r catalyticamountof BuLi l<.:.:r Diels-Alderreactionsto

o

(R)-r (l) C6F5CHO +

(R)-r ,.r D CH""Y" "CoH, cLcir, -zs', uotss-pL,SC.Ht

eo%

|

CHt

-,-1

1I\i

CH,

EE%ee

Cl:C:71cHr

(ll) Cl3CcHO + CHr:e(e11)z fr

OH CH, (S),74%ec I K. Maruoka,Y. Hoshino,T. Shirasaka, andH. yamamoto,Tetrahedron Letters,2It,3967 (1e88). 3

= 65:35) \cisltrans g f

ll

OH

i 3 5 a( 1 9 8 2 ) . _!\S).

Blue tetrazolium,1.,61. oxidation of steroid enones.r 3-Keto-Aa-steroidsare oxidized by blue tetrazolium (1) in an alkalinemediumto 2,6-diketo-Alsteroids in iT-gTvo vield. Other examples:

gH,l C:CHSn(CHrL (1).

-f-r

cH"l

",",o1,o", r^l^Y

CH, a: :nc (Z)-isomerbY additionof ) I: ;oupleswith allYlic,benzYlic, .electivelYbY rePlacementof { C :. .rlsoreplacedbY halogenon 45' 969(1989)' rl: : :ic-r.Tetrahedron,

657o 27Vo

cH.l

* oH

#

a\)/\/

l l oAffo

l

o

cH.l

-

l

a\l;\/

l l l o\)fon o

J Jasiczak, (1988). J.C.S.Chem.Comm.,2687 rinum 114.46-47). by (n)dc. *rth alkenescatalyzed with markedenana,.r.:. .rlcohols

1 Borrbicyclo[3.3.1]nonane(9-BBN). Enamines--->alkenes.t Hydroborationof (E)-enaminesof aldehydesor ke:r.oeswith 9-BBN followedby methanolysis (retention)affordsalkenesin 60-g0vo

U

Boron(lll)

chloride

sulfide (BMS) and including The same reaction, but with borane.dimethyl yield. 'u affords the isomeric alkene. inut o*ioution with alkaline H2or, r)9-BBN 2) CHgOH

101 L*/

H

><

cuH,

coHt

i<'

Boron trifluoride ethentc. T 3-Acyltenahy condensationof (Z)-4-hydror-vhigh diastereo-and enantioccb cis. trans, trdt?s-tetrasubstitutc tivity.

cuHt

c.H,

H

\J

/-\ C,H,

OH

c",Y\\'cH,

9uHt

BzlO

H

CH,

OCON(i-Prh

anti-l

111' 384 and H C' Brown' Am' Soc'' rB. Singaram,C' T' Goralski' M' V' Rangaishenvi'

(1e8e). Borane-DimethYl sulfide' ozonides This reagent(3 equiv') t:9ot:t Reduction of ozonidesto alcohols't reduction at22'\ng"n"'ully high yield without of alkenesto alcoholsin CHzClz of estergroups. l' Org" 54' 1430(1989)' andK' Jalali-Araghi' I L. A. Flippin,D W' Gallagher'

""'A:lil;T::l:

l with ortheseesters esterc;rreatment _azidoatkeneboronic the

of (a)' These undergo selectivemigration BCl, provideschloro derivatives alcoholysis' (3) on or piperidine r,r-aminoalkylgroup to **"1-Oytt"tilUine BCr".-?8. l- fr % rJre"^rtoc,H,)' [rg*:tt l, n=1 n=2

I + (CHTLC=

Allylic alcoholsfron nSt rhesisof alkenes(11, 474) to e equiv. of BF. etherate,c-allot adductsthat are convertedto I This reaction was develoPeds Corey'slactone-aldehyde,but

rlgr\t.'1 R-_ so2c6lt

f"",o" rCu,l.z\H .-*n=1,89% -, ' n = 2 ' 7 9 4 a

J'C'S'Chem'Comm'' rJ. M. Jego,B. Carboni,M' Vaultier'and R' Carrie'

142(1989)'

Boron trifl uoride etherate

and including

Boron trifluoride etherate. 3-Acyltetrahydrofurans. These products can be obtained by BFr-catalyzed condensationof (Z)-4-hydroxy-1-alkenylcarbamates with aldehydesor ketonesin high diastereo-and enantioselectivity.r Use of a (Z)-anti-precursor(1) resultsin cis,trans,trdns-tetrasubstituted tetrahydrofuransfrom aldehydeswith high selectivity. OH

BF,'qc,H')r ) + (cHr)rcHCHo

cHr>A.1zcH, l

i

BzlO

CH,

l

a

o

%

OCON(i-Pr),

anti-l

rr \,)c..111'384

cHr. -\-' .,cocHl CH". / \ -\'\o2-'"rt""' BzlO

eiucesozonides ith(,utreduction

2 cH3\____1,,cocH3 I + (CHr)rC:O ;+ CH3_ / 6ub

I r lq\9).

\-CH,

')-\oxt"; [e\c estersl with nrs.rationof the rrhrrivsis.

"t,t'l

Allylic alcoholsfrom sulfones.2 Polishchemistshaveextendedthe Julia synthesisof alkenes(ll, 474)to a synthesisof allylic alcohols.In the presenceof 1 equiv. of BF. etherate,o.-alkoxyaldehydesreact with lithiated sulfonesto form adductsthat are convertedto allylic alcoholson reductionwith sodiumamalgam. This reaction was developedspecificallyfor a synthesisof prostaglandinsfrom Corey'slactone-aldehyde,but shouldhavewider application. qH

r) LDA,rHF I l.r,oH

)

,\H t. .tt -,? l. 1.:-: . l-12(1989).

R-_

SO2C6Hr+ HCOCHCTH,, I

osiR3

#RvA-

-CHCsHil I

c6l{5so2 I ofR, ?5 I l) cHrsorcl - _RsG -- -lr) Na/Hs,Na"HPo.

*:A'r"tt" I osiR3

Boron trifluoride etherate

6

etherclaisen condensationof acetoacetatedianion.t In the presenceof BF3 tetrathe with condensation Claisen undergoes of acetoacetate ate the dianion I)' The (2' equation polyketides form to 1 acids of dicarboxylic methyldiamides

Pho tocyclization ol eryli anthrenes(13,231) can be ex usedas activatorfor the imirx R'

o ll

cocH2CCH2COOCH3

coN(cH3)2

o

N

1)NaH,BULi,THF I zlBF:.AczHs)z , i'ql g , ;'_" 1t%

i l * (TLl" l 0) cH3ccH'coocE

tl

R^.2

cocHrccH2coocH3

coN(cH3)2

ll

o

l,n=4

2(o=4)

R'= H, OCl X=CtL!i

,rr. | "4on",r,,*

+

o o H coocH3

I

nAl I,R=t[ot;

D. Hoppe,T. Krdmer,C. F.Er& I B. Achmatowicz. E. Baranonr hedron,44,4989(1988). 'M. Yamaguchi, K. Shibaro. H. ! 'C. M. Thompson andS. Darcr.

cHrcoocH3

Bromine. Bromolactonization.t Ra carbonateresultsin bromirr< erally are higherthan thoseot

3

o

o

/-/--coocH3 | | \

l l O

l

-COOCH, l

o

o

H

Hc, /+acoocH3 ll I

--------+ \ .nqo... \.-\ (o""'ou)

-CH2COOCH3

-'\7z\

,

O t

^ - t

cyundergoesacid-catalyzed product (2) obtainedfrom tetramethylsuccinamide is adipamide, an 2, from of clizationto the aromaticsystem4; but aromatization effectedwith treatmentwith calciumacetateat 80'' can be usedfor a geheralsynthesisof This BFj-promotedclaisen condensation from esters(equationII)' 3,5-dioxoalkanoates

?

r)NrH,BuLi,?

+ cu,Ccnrcoocg,4 0t) RCoocH,(c,Hs) R = n-CrHrr R = CICHz R = CeHs

...C\COOH

r'r

( / +

4

?

R. C. Cambie,P.S. Rutledge. I

Bromine-Methanol. RCHO -> RCAOCHy 1 dehydeswith Br, in CH,OH rr: to optically pure aldehydeso reactionwith aromaticaldehrt

ntcHrccnrcoocH3 60Vo 43Vo I L-/O

(r) RcHo#f

Bromine-Methanol

E rresenceof BF. etherGn.ilron with the tetrale- 2. equationI). The

o

g

Photocycrization of The photocyclizationof stilbenesto phen.aryrimines.a anthrenes(I3,231) can be extendedto aryliminessuchas l when BF, etherateis usedas activatorfor the imines. R'

tcH:ccH2coocH3

,w,BF3. O(C2H5)2 c'l/ct2 > 38-45%

l )cH.ccHrCOOCH3

o : tn = q) -.+ I I ca(oAc)2,80'

r,R=H,CHr; R'= H, OCH3; X=CH,N

OH

Ylcoocu, /"-,tv-\c12coocH3 Bromine. Bromolactonization.t Reactionof unsaturated acidswith Br, and thalrium(I) carbonateresultsin bromine-substituted ractonesin moderateyierd. yields gen_ erally are higher than those obtained with NBS in CHrClr, THF, or DMF.

I,!

)cl{

CH2COOH Bry,n2cQ cH2Ct2

........-

62%

cy;1g.'g.acid-catalyzed l. trom an adipamide,is ft r .' generalsynthesisof

o

o

tl RCCH:CCH2COOCHI

1>" +

Br I

'Br

30:70 R. C. Cambie,p. S. Ruttedge, R. F.

p. D. Woodgate,Synthesis,1009 Somerville, 09gg).

Bromine-Methanol. RCH, --->RCoocHt This conversioncan be efiected by oxidation of aldehydeswith Br, in cH.oH via.ahemiacetat (efuation I). The methodis appricabre lo optically pure aldehydesobtained from'ruga.s. yields are moderate in the reactionwith aromaticaldehydes. r

(r)RCH. "cH,oH[n"J+,_u-Rcoocq

48

(EF(2-Bromoethenyl)diisopropoxyborrne

This reactioncan be extendedto primary alcoholsand to uic-diols,both of which can be oxidizedto aldehydes.2

q*oH cH,+d cH'

oH I [o '"T,'4'"?f'o, 'n,o" ' ------ 'l| **J"o.r. l*J" 84% l-'--o^^coocH3 \

Preparation:

Bt-,4sn

(E)-1,3-Dicncs. h a vinylzinc chloride to f the presenceof a bar (

i

CH.IO -

CHt

CtL:C/S " \

(ao+ 17')

A HO

NrIo' > [".-O-""J

#

z

"",oo.0coocH3

OH

rD. R. Williams, Letters,29, E. E. Allen,F. W. Lichtenthaler,Tetrahedron F. D. Klingler, 5087n988). 2F. W. Lichtenthaler, (1988). P.Jarglis,andK. Lorenz,Synthesis,790

BuAzo Bromine fluoride, BrF. BrF is convenientlyformed from Br2 in CI.CF and used directly. Aromatic bromination.r BrF readily undergoesboth ionic and radicalreacradicalreactionand permits tionswith arenes,but additionof C2H5OHsuppresses electrophilicbromination.Simplearenesgivemono-and dibromoderivatives.BrF is more usefulfor brominationof deactivatedarenesas shown.

(E)-(2-Bromoetheny of I to couple alkylzirr rhis reagentis unsatisfrc

S. Hyuga,N. Yamashim C6H5CN-II-

nr-BrCeHnCN + o-BrCuHoCN (81Vo)

C6H5CHOd

(r0%a)'

$Bromo-9-phenyl[roru

m-BrtaH4CHO

rS. Rozen,M. Brand,and R. Lidor, J. Org.,53' 5545(1988)

"t\4u(o-t-Pr), (E)-(2-Bromoethenyl)diisopropoxyborane

(1).

N-Protected c-crdr trdes can undergoraceu rrth a phenylfluorenyl(F .aen to silicagel. A tni

9-Bromo-9-phenylfluorene

oth of which

Preparation: ut-.^r"rr+

(cHr)rcHot

1, b.p. ?3./12 mm.

#

(E)-1,3-Dienes. In the presenceof ClPd[P(CuH,)J,this borane reactswith a vinylzincchlorideto form an intermediatethat coupleswith an alkyl chloridein the presenceof a base(LiOH) to give an (E)-1,3-diene.

,r*J"a,""r,

!.oo.",

s(cH3)3 CH':Ct'". Letters,29,

,

CoH,

E,99%

BuAzncr +coH,cHpt +F ,('F and used I r.rdicalreacn .rndpermits I n \ . r t i v e sB.r F

-a>

CA-'"H' 8,96%

(E)-(2-Bromoethenyl)dibromoborane, BrCH:CHBBr2, can be used in place of I to couple alkylzincchlorideswith an alkyl chlorideto form a monoene,but this reagentis unsatisfactory for couplingof alkenylzincchlorides.' S. Hyuga,N. Yamashina, S. Hara,andA. Suzuki,Chem.Letters,809 (1988).

l Bromo-9-phenylfluorene,

N-Protected a-amino aldehydes,t Boc- and Cbo-N-protecteda-amino alde:rdes can undergoracemizationunder usualsyntheticapplications,but protection rrth a phenylfluorenyl(PhFl)groupprovidesconsiderable configurational stability, .\en to silicagel. A typicalpreparationis shownfor N-(PhFl)-r--alaninal (2).

N-Bromosuccinimide r, N(C2H5b,

lgl%!gg' CH3CHCooSi(cHJ3

cH3cHcooH l;-' Nttpnrl

NH,

/\ O

r) LiArH4

I

\

)

= 1Y " cr,gH-8u -t cH"cH-[-N'o)+% "."T'._ ew. _ LJ rMii\_cHo NHPhFI -u^^' (667o overall) \r'

Y*

i".

(2) is readily N-Protected s-amino ketones'2 N-(-Phenylfluorenyl)alaninal ketones(3) by reaction,ofa Grignard convertedto a variety of N_phFl-c-amino NCS and S(cH3), (corey-Kim rewith reagent(excess)followed by oxidation OH

'e#- t"'-Aru l

"

Ncs s(cH:h,g11" soso y

O I -Bu N}IPhFI

NUpnn

reaction,whereasa protectingctbr can be used for regioselective@u[ pentenylCtFo pling a 2-benzylated iodoniumperchlorate(f0. 212-:l: benzylatedpentenyl glycoside as are then replaced[ | dissacharide endwith the z-pentenylanomencq to give a trisaccharide.

D. R. Mootoo,V. Date,andB. Frrr andB. U. Udodong. P.Konradsson,

Bromotrimethylsilane.This silam anhydrousNaBr in dry DMF at I Silyl enol ethets.t Reaction , BrSi(CH:).and triethylamineresu ally the (Z)-isomer. Examples:

3

agent).Deprotonationandalkylationoftheseprotectedct-aminoketonesoccurs a'-alkyl branched of diastereomeric at the a,_carbonatom,o p.ouia" a mixture followed by methanol in a_amineketones. These ketones on hydrogenolysis enantiomeric high in acids periodateoxidationgive c-alkyl substituiedcarboxylic purity.

r)KHMD.

3 ;i;;;i, cltvL*# ?

I cH'

I PhRNH n

l]ti

o

".'

ovqu

? E cHscctLcH'o lt

cH3ccH2cooc

ll

"o\* crl 'R)-5 (997oee)

o ll

HCCHTBu 1;

Am' Soc''109'236(1987)' rW. D. LubellandH. Rapopoft, ' ldem,ibid.f10' 7447(1988)'

I

I

S. Ahmad,M. A. Khan, and J. lqbc

N-Bromosuccinimide. B) with glycosides("itl"::,:t Deglycosidation-t Treatment of n-pentenyl N B S i n l , T o a q u e o u s a c e t o n i t r i l e r e s u l t s i n l i b e r a t i o n o f t h e a n o m e ror ichydroxyl results in a glycoside a digroup. Brominolysis in the presenceof an alcohol protected benzylic or ester groups are not saccharide(in the caseof sugar-oH.) benzylic ether group on c, slows this affectedby this brominolysii a protecting

t3R)-Butane-l,3-diol, *{ aluminumhydride reductionof g nch. Fluka.

(3R)-Butane-1,3-diol

t{

\-cHo CH, (2) is readilY )u..::rrnal rcr.tron of a Grignard ('Il I (CoreY-Kimret)

Agu illP:.Fl

51

reaction,whereasa protectingether group haslittle effecton the rate. This effect can be usedfor regioselective couplingof glycosidesto a trisaccharide. Thus coupling a 2-benzylatedpentenyl glycosidewith a 2-acetylatedpentenyl glycosidewith iodoniumperchlorate(10,212-213) resultsin a disaccharideformed from the 2benzylatedpentenyl glycosideas the glycosyldonor. The acetyl groups of the dissacharide are then replacedby benzylgroups,which now activatethe reducing endwith the n-pentenylanomericcenterin glycosidation with anothersugaralcohol to give a trisaccharide. I D. R. Mootoo,V. Date,andB. Fraser-Reid, Am. Soc.,ll0, 2662(l9gg);D. R. Mootoo, P. Konradsson, U. Udodong,andB. Fraser-Reid, ibid.,lf0, 55g3(19ggi. Bromotrimethylsilane. This silanecan be generatedin situ from clSi(cH.), and anhydrousNaBr in dry DMF at 25". silyl enol ethers.t Reactionof carbonylcompoundswith in sl/u generated BrSi(cH:). and triethylamineresultsmainlyin the thermodynamicsilyl ether,usually the (Z)-isomer. Examples:

_1

o-rmrnoketonesoccurs mcnc a'-alkYlbranched rn(thanolfollowed bY id. rn high enantiomeric

o

Brsi(cHr)3,.N(c2H5r !s(c4;,

ff

cH3ccH,cH3 +i-

cH,\cH' I

H ( Z / E= 9 : r \

?

?si(c*)3

CH3CCH2COOCTH, ffi-

CHr\H

cooc2Hs (E/Z=r0o:0)

,-^--..,-,Pt I CH, -S 99% ee)

?

HicH,Bu -*

?Si(C::L

n\Bu

H (ZlE = 94:.6\ S Ahmad,M. A. Khan, and J. Iqbal, Syn.Comm.,U, 1679(19gg).

de. reither0 or P) with ( :hc anomerichYdroxYl t: rr .i qlycosideor a dic ,,: cstergroupsare not ir irtrup on C2slowsthis

?"

rJR)'Butane-1,3-diol, cur cHrc4oH (r). Thediorispreparedrby lithium ruminumhydridereductionof poly(3-hydroxybutyric acid),available from Ald:ch. Fluka.

52(2s,4s).N-(,.Butoxycrrbony|)-4.(dicycrobutylphosphine).2.[(diPheny|phosphino)methy|]pynolidine

The acetal 5-Atkyl-3r5'dihydroxypentanoicacids; chiral hydroxylactones'2 1,3-bis(trimethylsilyloxy)-1with (R)-1 couples (2) of an aldehydeformld from methoxy.l,3.butadiene(3),togiveasingleisomer(a).Thechiralauxiliaryis ,cH3

o--<' R--{

)

b_/

rCH,

coocH3

rMS? ?*t + s,cMocH,#

*\4 ,,.u I 6-I--.",

Asymmetric hydrogenation of ) C: fective ligand for asymmetrichydrogenatir ( - )-pantolactone(3).'

CH,N

ll!?,,*"."o.o.,,,

o^ro o ,

(cHt2oH

2

tq. tRXCWt

4

n-rzLJ i

l

og

d 5

coocH3 (cr'<)rBocHr, '-ri,brl - l

s

t

nm{

loocH3

r*\ry %

i

This chiral bisphosphinein combinati efficientasymmetricreduction of suitably-s 2'3 o-aminoacetophenones.

i

oH

oH

}}1.

6

c6H5cocH2Nr{R ry

_^_ | HF/py 'octt3cx |

RY,,Y,OH l

OJ

l

tl

o 7

removedbyoxidationwithperiodinane(112,378_379)followedbyp-elimination (5) is then promoted by dibenzylammoniumtrifluoroacetate.The resulting aldol to the syn-1,3-diol6. Saponificationand lactonization reduceddiastereoselectively givesthelactone?.Lactonesofthistypearepresentincompoundsinhibiting biosynthesisof cholesterol. I D. Seebach andM. Ziiger,Helv',65,495(1982)' 3757(1988)' Letters,29, 2W. S. Johnson, A. B. i"lron, andJ. D. Elliott,Tetrahedron (2S,4S)-N-(t'Butoxycarbonyl)'4'(dicyclobutylphosphine)'2'[(diPhenylphos' phino)methyllpynolidine (BCPM, 1)' Preparation''

cv'P\--

H. Takahashi,M. Hattori, M. Chiba, T. }|6i n.4477 (1986). 'H. Takeda,T. Tachinami,M. Aburatani.H. i b i d . , 3 0 , 3 6 3( 1 9 8 9 ) . T. Takeda,T. Tachinami.M. Aburatani. H. b i d . , 3 0 , 3 6 7( 1 9 8 9 ) .

| 25,45)-N-(t-Butoxycarbonyl)4-lbir({'-ril dimethylphenyl)phosphinol.2.{lbis(4' (2S.aS pbosphinyllmethyllpynolidine [r, furP

;(*)At*,

I cooc(cHr\ I

(*)^r,..",,' I

cooc(cH)3 1, m.p. 174o,co-4lo

Asymmetrichydrogenation. Simphr r-diphenylphosphinyl-2-(diphenylphos ':ported in 1976(8, 57-59) to be usetulf :emidoacrylicacids. Since then a para-trc

MOD.BPPM

$crr lpbocphino)methyllpynolidine lydro4-loctones.2 The acetal h . .:-bis(trimethylsilYloxY)-1I '1, The chiral auxiliarY is

coocHs .

l) lol

\,'

ziili"un.nococr,i)

--cti.

53

Asymmetic hydrogenation of ) c:o. This bisphosphineis the most effectiveligandfor asymmetrichydrogenationof ketopantolactone (2) to provideR( - )-pantolactone(3).1

cn,-;{' I

{Rh(coD)cll2,r

o?rffiHo,.vo r't O

H. '.OH

cn'f{'

H2, \

2

'--

|

\

il

O

(R)-3,92Vo ee

I

This chiral bisphosphinein combinationwith rhodium complexesalso effects efficientasymmetricreductionof suitablysubstitutedcarbonylcompoundssuchas 2r a-aminoacetophenones.

"ffi,*ar c6H5CocH2N'HR

C,E yq;*

o

(S, 85-977o ee) H. Takahashi,M. Hattori, M. chiba, T. Morimoto, and K. Achiwa, TetrahedronLetters, 27, 4477(1986\. 'H. Takeda,T. Tachinami, M. Aburatani,H. Takahashi, T. Morimoto,and K. Achiwa. t b i d . . 3 0 . 3 6 3( 1 9 8 9 ) . T. Takeda,T. Tachinami,M. Aburatani, H. Takahashi,T. Morimoto, and K. Achiwa, t b i d . , 3 0 , 3 6 7( 1 9 8 9 ) .

-:-v r followedby P-elimination Thc resultingaldol (5) is then cationand lactonization Sa:r.nrfi tc\.xt rn compoundsinhibiting

(1988). Vc, n Leuers,29,3757 tline )-2-[(diPhenYlPhos' !

| 25,4S)-N-(r.Butoxycarbonyl)-4.Ibis(4,-methoxy-3,,5'dimethylphenyl)phosphinol-2-{[bis(4,-methoxy.3',5,-dimethyl)pbosphinyllmethyllpyrrolidine [1, (2S,4S)-MOD-BPPM)]. turP!_

(*)^r*,

*=""r;b

I

cooc(cH3)3 I

Lr

Asymmenic hydrogenation. Simpler ligandsof this type, but still basedon a r-drphenylphosphinyl-2-(diphenylphosphino)methylpyrrolidine (pppM), were first ':ported in 1976(8, 57-59) to be usefulfor asymmetrichydrogenationof 2-ace'-rmidoacrylicacids. Since then a para-methoxygroup on the phenyl groupshas

54

r-Butyldimertylsilyl

been found to acceleratethe rate, whereasmethyl groups increaseenantioselectivity. The presentligand (1) hasbeenshownto be particularlyusefulfor a rhodiumacidsto the corresponding(R)catalyzedhydrogenationof (Z)-2-acetamidoacrylic with high enantioselectivity. and mild conditions amino acid derivativesunder H1

Rt

r' tnrrt*sificroa'

-,\,"oo*: A I NIIAc

R2

qH'

-,-l-*-cooR' R ' Y

I Y. Lee,H. Iwasaki,Y. yamamoro

R ( 8 5 - 9 8 . 6 7 oe e )

CHr) 1R' R3=H, ,

t-Butyldiphenylsilyllithium. This hindered reagentcan bc in THF at 0". It adds to keroo rearrangementto a silyl ether i corresponding silylcuprate,[(C.H enonesand unsaturatedesten in

I H. Takahashi and K. Achiwa, Chem- Letters,305 (1989).

\<>oH(l) 'oH

CycliZation of enynonesto methylenecyclopentenones.This cyclization can be effectedunder thermal conditions,particularlyin the caseof activated(Z)is observedwith reagents enynones,but in only moderateyield. Someacceleration but dramatic knownto promoteenolization(LiCl andcollidinep-toluenesulfonate), more marginally E is effectscan be obtained with phenolssuch as 1.. Vitamin Bzl\2^.

coHj

o €

oH ------+

ceH;

|

./-_4 coH'

Fo

t, 83'

P.Cuadrado, A. M. Gonzdlcz, B. G

t-Butyl hydroperoxide-( + )-DEf Sharplessepoxidation of alta enantioselective Sharplessepoxi suchas styreneoxide in high opr tl) with ClSi(CH3)rHgives2. whi lessepoxidationof 3 givesthe cp bv cleavagewith fluoride ion. Tt to that of the correspondingalyli

\"a",

CH3 830

(R2 = !l

2, R'= g, 611r,

r.lga.

r[r-Butylcatechol, (CHr)rC{

+ CHr:el

CrHt.-^L. l0Vo 92Vo

of phenols effectivethanthe simplerphenol1. The reportattributesthe effectiveness reaction. to a singleelectron-transfer for conversionof enynonesto phenols. SeeCollidinep-toluenesulfonate rP. A. Jacobi,L. M. Armacost, Letters,29, J. I. Kravitz,andM. J. Martinelli,Tetrahedron 6869(1988). 10, 63; 11, 90-91; 13' 86' l-Butyldimethylsilyltrifluoromethanesulfonate, Diels-Atder catalyst.t In the presenceof this triflate (1) and 2,6-lutidine, to givecls-fusedadducts to a,B-enones chromones(2) undergo[4 + 2]cycloaddition in generallyhigh yield (75-95Vo).

clsiH(cH3ha.4-, D

,-Butylhydroperoxide-(+)-DET-Ti-(O-nPr)r

55

Du} rncreaseenantioselecnrr.,r.rusefulfor a rhodium(R)b : ' :he corresPonding enantioselectivitY. r h:r:

- .

2, R'= H, CH:, qH5

^^^^3 LUUK

I Y. Lee,H. Iwasaki, Y. Yamamoto, (1989). K. Ohkata,andK. Akiyla,Heterocycles,29,35

\t{Ac ar 6oc ee)

lJ

t-Butyldiphenylsilyllithium. This hinderedreagentcan be preparedby reactionof l-Bu(CoH.),SiClwith Li in THF at 0". It adds to ketonesto form c-hydroxysilanes.Evidently a Brook rearrangementto a silyl ether is unfavorablebecauseof steric hindrance.The corresponding silylcuprate,[(CuH,)r+-BuSi]rCuLi, undergoesconjugateadditionto enonesand unsaturatedestersin good yield.' P.Cuadrado, (1989). A. M. Gonzdlez,B. Gonz{lez, andF.J. Pulido.Syn.Comm.,19,275 ,ones. This cYclizationcan n :hc caseof activated(Z)!r\,: r\ observedwith reagents lucrc.ulfonate).but dramatic it.rnrn E is marginallYmore Bzl;4

4

l

F

a6 l Jr ' 5 1

o \\ bHCH.

: ,: -:-

r-Butyl hydroperoxide-( + )-DET-Ti-(O-i-Pr)n Sharpless epoxidationof alkenylsilanols.t Allylic silanolsalsoundergohighly enantioselective Sharplessepoxidation.This reaction furnishessimple epoxides suchas styreneoxide in high optical purity. Thus reactionof rrans-B-lithiostyrene t 1) with ClSi(CHJiH gives2, which can be oxidized to the alkenylsilanol3. Sharplessepoxidationof 3 givesthe epoxide4, which is convertedto styreneepoxide5 bv cleavagewith fluoride ion. The stereochemistry of epoxidationof 3 is similar !o that of the correspondingallylic alcohol. C'Ht.-,/-Li I

-up

coHr-.,4siH(cH3),ot'or#*o',guHs€ Si(CH"),

t - -

,

OH 3

Irc. :he effectivenessofPhenols

| (-BuooH) 5 0 7 |o( + ) - D E T I T(o-i-Pr).

ol r1\nonesto phenols. Lefters,29, fl::'. r Jllr. Tetrahedron (C2H5)aNF

6: 11.90-91;13,86. b :::li.rle (1) and 2,6-lutidine' c:r,':rc\ ro give cis-fusedadducts

c'Ht-*A # c u H , - A 5 (85Vo-95%ee)

-si(cH3)' I OH

56

l-Butyt hydroperoxide-Dioxobis(2'4-pcnlmedionrte)molybdenum

'T. H. Chan,L. M. Chen,and D. Wang,J.C.S.Chem.Comm.,1280(1988).

ruthenium(Il). r-Butyl hydroperoxide-Dichlorotris(triphenylphosphine) Oxidation of tert-N-methylamines with Oxidative dealkylation otkrt-amines.l r-BuOOH (2 equiv.) catalyzed by this ruthenium complex results in a-(rbutyldioxy)alkylamines. N-Methyl groups are oxidized selectively in the presence of cH, cuHr*-cH,

cH2ooc(cH3)3 ,-BuooH, Ru(D) t'"' t g6H5NCH3

r,II ""6 -

exclusivelyto ketones.The carbo4 benzeneand chloroform are the sd HO OH

l

t

(C6H5)2C-C(CotllOH I C6H5CH-CH,OH E K. Naneda, K. Morimoto,andT. lnl

H t-BuOH+ HrO C6H5NCH3+ other alkyl or alkenyl groups.Amides are also oxidizedat the cr-positionof the nitrogen.

r.Butyl hydroperoxide-Pyridirn c Oxidation of alcohols or rety rdiniumfluorochromate(PFC): asc vield. This combinationalsoefiecrs vlenegroupto a keto groupin mode 16-63% yield; fluorene---rfluorenq

J. Muzart,New.l.Chem., 13,9(l$9f M. N. Bhattacharjee, M. K. Chaudhu ooc(cH3)3 bicyclicaminesvia an imOxidationof homoallylicaminesresultsin cl's-fused (a). inium ion

r.Butyl hydroperoxide-Pyridiniu i 2,5-Cyclohexadien-l-oncs. Thi Jisubstituted1,4-cyclohexadienes ro

ll il-

.fi3F* I S.-1.I\{urahashi, (1988). T. Naota,andK. Yonemwa,Am. Soc.,110,8256 11, 91l' 12' t-Butyl hydroperoxide-Dioxobis(2,4'pentanedionate)molybdenum, 89. Cleavageof vic-diols.t C-C bondssubstitutedby hydroxygroupsare cleaved by this systemto ketonesandcarboxylicacidsin highyield. Di-rert-diolsarecleaved

{. G. Schultz, A. G. Taveras. andR. E

r-Butyl hydroperoxide-Vanrdy' rtt Cyclopentenones.t Vinyl allene :dizedby r-butylhydroperoxideand' -rt% yield.

r-Butylhydroperoxide-Venadylrcetyhcetonste

ltttnc

57

exclusivelyto ketones.The carboxylicacidsare derivedfrom aldehydes.Chlorobenzeneand chloroformare the solventsof choice.

( '.''. . IlS0(1988)'

tline truthenium(II)' with n, . "f rert-N-methylamines d-(t-butylin ! i.'1lplex results of t .i :';trvely in the Presence

HO OH

l l 9ryffi (c6H5),i-c(cuH,), OH I I C6H5CH-CHTOH G

ci: rloc(cH3)3

(cuH,),c:o

C6H5COOH

L\. ii, I K. Naneda, (1988\. K. Morimoto,andT. Imanaka, Chem.Letters,1295

t t -

+ :-3:OH + HrO

of the D\:,::.'.d at the a-position

z4 I

l

l-Butyl hydroperoxide-Pyridinum chlorochromate. Oxidation of alcohols or methylenegroupsJ In the presenceof PCC or pyridinium fluorochromate(PFC)' as catalyst,l-BuOOH can oxidizealcoholsin good yield. This combinationalsoeffectsoxidationof a benzylicor a propargylicmethylenegroupto a keto groupin moderateyield; for example:indane--+f -indanone, 16-63% yiefd; fluorene--+ fluorenone,53Voyield. : J. Muzart,NewJ. Chem.,13, 9 (1989). : M. N. Bhattacharjee, M. K. Chaudhuri, andS.Purkayastha, Tetrahedron, 43,5389(1987).

o

\z^y--1.", ooc(cH3)3 via an imamines b-::--:JhrcYclic

t-Butyl hydroperoxide-Pyridinium dichromate. 2,5-Cyclohexadien-l-ones,This system(1:1) is effectivefor oxidationof 3,3disubstituted-1,4-cyclohexadienes to 2,5-cyclohexadien-1-ones.'

OH

I| I

r"l\

. \

./\]^\|

' n H - l D t

I

|

\.,-t---*-cuH, H

ll0. 8256(1988)'

12' barte tmolYbdenum,1tl',9l'' arecleaved it:'.r: or hydroxygtoups arecleaved o :.,.. t i.ti. Di-tert-diols

. ra\;'#:} l l l l - 't4 * -

cH,)>1 -cH, cHr6oc-

o tl

r-

cH,* -cH3 cH3ooc-

{ G. Schultz, A. G. Taveras, andR. E. Harrington, (1988). Tetrahedron Leuers,29,3907 rButyl hydroperoxide-Vanadylacetylacetonate. Cyclopentenones.tVinyl alleneswith a directinghydroxylsubstituentare oxr:zed by /-butyl hydroperoxideand VO(acac),directlyto cyclopentenones in 401 ': r'ield.

t Butyl $teto4'hexenotte

Butyllithium. Cyclopropanation.t The chiral bis(l ment with BuLi (4 equiv.) cyclizesto a m in the ratio 1:3, which is readilyseparat hydroxylgroup. Higher diastereoselecti cH3

+I

Y

cH3

+ rF).n"'"{::::: l-4-".-l.oH

o tl |"-cH,on

w

CH,

Pr

tt{ R\-Hq

I S. J. Kim and J. K. Cha, Tetrahedron Letters,29,5613(1988).

tl

o o

' ll

I

I r-Butyl &keto4hexenoate, CH3CH:CHCCHzCOOC(CH3)3 (1). Preparation. cb-Dccalins.z The enolate of this Nazarov reagent (1), conveniently gener(2) to form a ated with CsrCOr, reactswith 2-methoxycarbonyl-2-cyclohexenone product that is cyclizedwith TsOH in CuHuto the diketonesexo- and endo-3 in a ratio that is dependenton the solvent. In a nonpolar solvent exo-3 is favored,

o ..\.t (/

the triisopropylsilylether of 1 (l : I l). Rct is effectedby N-t-butoxycarbonylation (lI a-Oxy-o-xylylene (a1.2 Treatment o{ with BuLi at 0'generatesan c-oxy-o-x-v ophiles.Thus, the reactionof a with mcr!

cH" +

71

l) C!2CO3 2) TOH, CrHe --i+

l

V

.'oH(Ac)

,".,-?"r1-o lO -L\

-"

2, E = COOCHg co2c(cH3)3 I cHcl3 DMF

99.5> 0.5 55:46


OH I

\-\-). whereasin DMF or CHrCN the ratio is about l.:1. The report presentsevidence that a [4 + 2]cycloadditionis involved at least in the nonpolar solvent and that the reaction may involve a sequentialdouble Michael addition in polar solvents. I D. Liotta,C. Barnum,R. Puleo,G. Zima,C. Bayer,andH' S' Kezar'J. Org',46,2920 (198r). 2J.-F.Lavalle€ (1988). Letters,29,5117 Tetrahedron andP. Deslongchamps,

endo -2

major adductsin the ratio 60:17. This rc of 1 at 110'with the samedienophilero gi in an endoI exo ratio of 1 : 4. Another eran in equation(I).

:K::I

Butyllithium

59

Butyllithium. cyclopropanation.t The chiral bis(B-phenylthio)carboxamide (1) on treatment with BuLi (4 equiv.) cyclizesto a mixture of the two cyclopropanes 2 and 3 in the ratio 1:3, which is readily separatedby chromatographythanksto the free hydroxylgroup. Higher diastereoselectivity obtainsby similarcyclopropanation of cH,_ - - r_cH" SC6H5 + nur_i, z=?t-o" -rn"to-{-r.,il r\ l\

o

I

tl ^-cH,oH \__f

I

I ^,-

lz-/--'-L.vH CH, I

Pr

u.ArscuH. RNHC" "H

s.

H\_..H * ,r nNn;- - V\sc,H,

O ( l s ,2 R )- 2 )C ( t{,t, (l). Preparation.' generF:: I ). conveniently Gr. hexenone(2) to form a lc: :c. exo-and endo-3in a b: -,lrent exo-3is favored.

O ( l R ,2 5 )- 2

the triisopropylsilyl etherof 1 (1:11).Removalof the chirarauxiliary(d-camphor) is effectedby N-r-butoxycarbonylation (12,2g2\ and hydrolysis. a'oxy'o'xylylene (a).2 Treatmentof a benzocyclobutenor or the acetate(l) with BuLi at 0'generatesan a-oxy-o-xylyrene (a), which can be trappedby dienophiles.Thus, the reactionof a with methyrmaleate gives endo-and ero-2 as the

olil

I

6\aloHtac) ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ld | .",*..,,1,.".*.",,0., 444c v-

b

Lst"J

endo-3

oH w5>0.5 :i J6

lhc report presents evidence E r(,npolar solvent and that | :JJrtion in polar solvents. I H S Kezar,J. Org.,6,2920 .39 :ll7 (1988).

gH COOCH3

t\. .

-.

endo-2

t

l

l

+

Z\./-..COOCH3

l

l

l

\AAcoocH" coocH360:17

l

exo _2

major adductsin the ratio 60:17. This result contrasts with the thermal reaction of 1 at 110'with the samedienophileto give 2 as the only adduct(3r% yierd)brt rn an endoI exo ratio of 1 :4. Another exampreof the valueof this methodis shown in equation(I).

Butyllithium

l,A.{on(oot' (r)ll | |

,u'

\ZacuH,

oLil

o

Jf,,

L l l . ' d16qc "--

I

coH,|o-snaq

Loi,",l \

thiumsis the reactionof lithium napbt

//

{ i i H CuHt

4 BrrCCHrOSiR, I, R, = 1-Sqg11t

= i-Pr3

r.nor*,

56Vo

r) 2 LDA 2)c2H5oH r HC=cosiR. 96%

3

,

617o

\o"t*

o

Dehydrobromination,3 One approach to trialkylsiloxyalkynesinvolves dehydrobrominationof L, preparedfrom tribromoethanol,with BuLi (2 equiv.) to form (Z)-2-bromovinylsilyl ethers2, which can be convertedby LDA followedby alkylationinto siloxyalkynes(4). Theseproductsundergocycloadditionwith vinyl

-cH. ,t'"'\

anti-SeIect iv e I2,3lW i t ti g rcant4l (silyloxy)allylethers (1) provides thc regardlessof the geometry of the dout

9"' .

a,'1.rzosiC(Ctlt)i t l

o---l

.

cH,

CoHt I (UE\ = 7r:29 = 93:7

,o-r*-rrrr"oo cHt J 2)

cH3c=cosiR3 4 (5) to produceresorcinolderivatives ketenes(a), generatedfrom cyclobutenones (6).

t"'J,-ro

CH,

&sio

R/S,R=CHzOMOM

I K. Tanaka,I. Funaki, A. Kaji, K. Mior 7l8s (1988). r W Choy and H. Yang,J. Org.,53. 5'796 r R. L. Danheiser,A, Nishida,S. Savarie ( 1988). 'C. A. Broka and T. Shen.Am. Sac..lll 5 E. Nakai and T. Nakai, Tetrahedron La

CH, a

6

Cyclization of a-alkoxylithiums.a A usefulroute to tetrahydrofuransinvolves lithiation of (tributylstannyl)methylethers. Another useful route to c-alkoxyli-

I Butyllithium-Hexamethylphospbork a Nitroalkane dianions. Seebach with BuLi (2 equiv.) and excess HM reaction with benzaldehyde to form I reversed, addition of nitroethane to a dianion is formed as shown by reacti ratio of 3:4 is controlled by HMPT. lt Similar results obtain with l-nitroprop

Butyllithiun-Hexamethylphosphorictriamide

-JfH' /

coH,fotsnBu,

--JCH'

oo"r,

tou'

/

\

cun,i\o2 = ll:1) (cisltrans

thiumsis the reactionof lithium naphthalenide(LN) with a-(phenylthio)ethers. ,CH" { i : H CoHt

SJ/ asc,u, -11* 52sa

\o"{*

(_,

rr.,,rralkynesinvolvesdeil *rrh BuLi (2 equiv.)to rr:cJ bv LDA followedby with vinyl 3., -r cloaddition

n

,.CH.'

\ot* = 7:I\ (translcis

anti-Selectivelzr3lWittig reatrangements(cf., 12, 60). Rearrangementof a(silyloxy)allylethers (1) providesthe silyloxy 1,2-diol with high anti-selectivity regardlessof the geometryof the double bond of L. QH"

I

",.aott*, =--+ ^-oit.tcD,,#l!i,. cH,

!- ttC:COSiR:

d--l

3

-^ (^ coHt

Ho'

boH, I (7,/E)= 71;29 = 9t:7

du.c resorcinolderivatives

t

737o SlVo

antilsyn= 82:18 77:23

lK. Tanaka,I. Funaki,A. Kaji, K. Minami, M. Sawada,and T. Tanaka,Am. Soc.,ll0, 71850988). r W . C h o ya n dH . Y a n g ,J . O r g . , 5 3 , 5 7 9 6( 1 9 8 8 ) . r R. L. Danheiser,A. Nishida,S. Savariar,and M. P. Trova,TetrahedronLetters,29,4gll-

( re88).

'C. A. BrokaandT. Shen,Am. Soc.,flf,2981 (1989). ' E. NakaiandT. Nakai,Tetrahedron (1988). Letters,29,5409 ('tl, +

R SrO CH,

o :r: r.rhvdrofuransinvolves [.<.tu] route to c-alkoxyli-

Butyllithium-Hexamethylphosphorictriamide. Nitroalkanedianions. Seebachet al.t haveshownthat reactionof nitroethane with BuLi (2 equiv.) and excessHMPT generatesthe a,c-dianion as shown by reactionwith benzaldehydeto form 3 as the major product. If the sequenceis reversed,additionof nitroethaneto a solutionof BuLi and HMPT, then the c,Bdianion is formed as shownby reactionwith benzaldehydeto form 4.2Thus the ratio of 3:4 is controlledby HMPT. In its absence,3 is exclusiveproduct (57Vo\. Similarresultsobtain with 1-nitropropane.

Butyllithium-Potecsium t'butoxide OH l) BuLi'HMPr(2:l'

?"

2 ) c r l t s c H o' ' c u u r C u c H Nor+cuu'iucH'cu'No' -'"-"1;" -' c2H5No2'-A-

alkylation with BuI of the anion of (E)-cr-substitutedvinylsilane' (E)-Pt arated from the major Product' I A. Mordini,G. Palio,A. Ricci'andt

5:95

3

4

(3) A short synthesisof nitramide Spitocyclization of an epoxy sulfone'' BuLi of equiv' the epoxy sulfonet' with-2 involves as the key step the reaction of 2 (i37o yield)' Both therulfone and spirocycle ift" in THF/HMPA (9:1) to-i-t sulfonamidegroupsarecleavedbyfreshlypreparedsodiumamalgam(7'326-327)' Ts I

zn"u;fllf.Mm .TCHN(CHr)3SO,C?H?

CHTNHTs -&%

I\

\./

l"::o )"'

--G-

I

C?H?SO

Butyllithium-Tetramethylethylc' o-Lithiation of aryl thiok' 1' iation of aryl thiols. Thus lithium 2 yield by reaction of thiophenol ri cyclohexaneat 0 ---) 25o'r Howete directing grouP than a methoxy trc seneral route to substitutedarerE

o*6

"*f,o

N(Hs), CH'OH-, NaHPO., -

SH

d to related systemssuch as z'PYtn

Butyllithium-Potassium r'butoxide' of (E)- or (Z)-allylsilaneI' with a-Alkylation of allylsilanes'r Deprotonation (cH3I) provides the c-methyl subthis base followed in,,nJiut"rv by alkylation as the starting silane' However' stituted allylsilane(2) with the sameconfiguration

--

l) BuU, KOC(CH3b'-5f

0t,)Prvsi(cHJ3

t*Y---Prvsi(cHJ3

f

\^r,,.H3)3

(z)-r

I

2(ZlE= 5:95)

(E) -1

Pr

9H,

t"'

J*+ \A't"",1

2(ZlE= 98:2)

^'*ili3'-, t l c.Hrs

o/ I

Butyllithiurn-Tetrrmethylethylenedirmine

alkylationwith BuI of the anion of either (E)- or (Z)-l provides20-25%o of the (E)-c-substituted vinylsilane,(E)-pr(Bu)cHCH:cHSi(cHJr, whichis easilyseparatedfrom the major product.

OH

I

lf.\, ', - C6H5CHCH2CH2NO2

H

'A. Mordini,G. Palio,A. Ricci, andM. Taddei,Tetahedron (r9gg). Letters,29,4991

.'\ .: 'r1 \lnthesisof nitramide(3) pr. ..r.itrneI with 2 equiv.of BuLi -: rreld).Both the sulfoneand I fe:: : \drum amalgam(7,326-327). lr

I

Butyllithium-Tetramethylethylenediamine(TMEDA ). o-Lithiation of aryl thiols. Three laboratoriesr.2.3 report ortho-directedlithiation of aryl thiols. Thus lithium 2-lithiobenzenethiolate is formed in quantitative yield by reactionof thiophenolwith BuLi (2 equiv.) and rMEDA (2 equiv.) in cyclohexaneat 0--+ 25o.rHowever, a thiol group is less powerful as an ortho_ directing group than a methoxy group. Thus ortho-metalationof ArSH provides a generalroute to substitutedarenethiols.2 This ortho-metalation can be extended

It t :i ,SO.C'H, znuu, rxvxurr -20 )25o

I

63

--\i. 't

/

,

J"

qooH

ltt

cooH

0-ry''#d'-'S cts | (cH.),c=o --

I

I

".../r.iH '-oH

c(cHJ2 It F

lr:

t::

)'( [:

. e l v . , 6 5 ,1 1 0 1( 1 9 8 2 ) . . - , m a sH ; (' 5. Chem.Comm.,110(1989). - I etters.29,6493 (1988).

- ,'i lE)- or (Z)-allylsilaneL with i{ I r provides the c-methyl sub-,. the starting silane. However,

to relatedsystemssuchas 2-pyridinethioland 2-(phenylthio)tetrahydropyran (L).3

^ t c.Hrs

l o/ I

r! * "

CH.

I

, nAlsi(cH3)3 2(zlE= 5:95)

,"'.1;'^l*

-

?^o-

.,A.-Li

U

clsi(cHr)r, i^o, e1* '\,sitcH')'

U

cr* | ryxgcr2

ovaall

J

2) H2S

si(cHJ3 H,,. I

g

r-ButYllithium

rG.D.Figuly,C.K.Loop,andJ'C'Martin'Am'.Soc"111'654(1989)' ' K.Smith,C.M'Lindsay,andG'J'Pritchard'ibid''l1ll'665(1989)' J' Zubieta' 3 E. Block,V. rs*urutrisnnJn,-ta.G"rnon, G' ofori-okai, C' Saha,K' Tang'and ibid.. l'.l,658 (1989). /-Butyllithium. Lithiationofvinylamines.Thevinylicaminelislithiatedbyr-Buliatthe because of chelation with the dimethylamino tertiary vinyl position, f'"'u*uUty methylallylic amines also can undergo group (equation I)'' various allylic and

new method for deprotection is genc which is oxidized(O, or MoOPH) to t zylatedamide.Yields are moderateto 1,3-SiR3to Br rearrangemcnt'' / of SiR' t involvesa 1,3-rearrangement

oq:

To'

f"'

,,,aY\ ..*ra)-\ \./

Hrcl"\cH3

R) -r

'N,/

V)Li

")

\cH,

cHrl

O

dianions(equationsII and lithiationwith n- and r-Bu1-ito providevinylic lithiated III).'

0r)

\,,or",

iLf"'Vl*"*''"'t JC"'

c6H5NH

(rl)

o

l-1'l

c6H5NH

W.",

G. Stork,C. S. Shiner'C.-W'Chcng't F Foubc :J. Barluenga, F. J. Faflands, ' R. M. WilliamsandE. Kwarst'Icrrol ' K. Maruoka,T' Itoh,Y' Araki,T' Slir 61,2e7s(1988).

-*

tl

CHt

been used for protection of Protection o! amides.! N-Benzyl groups have resist hydrogenolysis.A amides,but in contrastto benzylarin"i, b"nrylamides

o

'u'''-'i", ll

I q

l]'d"t'.l^,.1 -.cHrcuHnocH,-p ---'

C^H.C-N'

i l ^ ^ . .I r .,.C"tu"oocu'-a |

luuU'C-N-

L J",

I

Butyltrichlorotin, BuSnCl, (l)' r In the Presctr Etherification into acyclic and cyclic ethers' Thc t BuSn(OR)Clr.This dehYdrationof etherswith 2 being the major Prod BuSnC13'

r5o-2oo' -(QtL\ -t4-.;;/ \ HO(CH),OH \o/ n = 4,5 n=13

I

ttn

D|'

! CH,CH:CHCHCHCH:Clt'

? CP,C-NH

+ OHCC.H.OCH'-P

cH"

OH I

-;

I

Butyltrichlorotin

F!'

T:ng.andJ.Zubieta,

65

new method for deprotectionis generationof the benzyliccarbanion(t-Bul.i), with releaseof the debenwhich is oxidized(O, or MoOPH) to the benzaldehyde zylatedamide.Yields are moderateto reasonablygood. 1r3-SiR3to Br reanangement.4 A new route to hindered chiral binaphthols of SiR, with t-Bul-i. involvesa 1,3-rearrangement

rd tr t-Bul-i at the thc dimethylamino , rrrt) c?It undergo

Br OSi-l-BuPh, ,-"ot n% OSi-t-BuPh,

Br (R)-2 I. F .quationsII and

L\Il

QCH, (R)-3 OH

\ir

I l " -

c(cH"),

andR. L. Polt,Am. Soc.,108,304(1986)' C.-W.Cheng, G. Stork,C. S. Shiner, :J. Barluenga, (1988)' andM. Yus,J.C.S.Chem.Comm.,1l35 F. Foubelo, F. J. Faflands, 'R. M. Williams (1989). Letters,30,45l andE. Kwarst,Tetrahedron ' K. Maruoka.T. Itoh.Y. Araki,T. Shirasaka, Bull Chem.Soc.Japan, andH. Yamamoto, (1988). 61,2975

CH, d i,rr protection of hr Jrogenolysis.A

,r.".nj

Butyltrichlorotin,BuSnCl. (1). Etherificationr In the presenceof BuSnCl., 1,4-and 1,5-diolsare converted into acyclicand cyclic ethers.The actualcatalystis an organoalkoxytindihalide' (1) resultsin three acyclic BuSn(OR)CI,.This dehydrationof 1,5-heptadiene-4-ol etherswith 2 being the major product. BuSnC13'

tso-zm' HO(CH2)"OH-rr_r8;] (t-(fHJ" .) -On = 4,5 n=1,2 BuSnC13

:CH, 4 CH,CH:CHCHCHCH l f.H.ocHr-p

OH I

CH,CH:CHCHCH,CH:CH, O CH,CH:CHCHCH,CH:CH' 2Ufr-509o)

+ 2 isomers

6

2-Butynal

r G Tagliavini, D. Marton, and D. Furlani, Tetrahedron,45, 1187 (1989).

2-Butyral, CH3C:CCHO. Phenol annelation.t A key step in a synthesisof the aglycone(4) of pseudopterosinA is a reactionof the silyl enol ether2 with 2-butynal(l) and (cH3)3siorf at - 78ofollowed by PCC oxidationof the resultingpropargylicalcoholto give 3 in 61% overallyield. CH3 I

R3SiO

Camphanoylchloride (1). Supplier: Al&i Preparationfrom camphoricacid: cH3-./ cH3

H

l) (cH3bsioTf -; 11Orcc

-CH,

.CH,

o

l

N-cH, /|\COO11 l

lAcoou

f

l) Pcr< zig"-, f

i

X Br

(+)

(m.p.215.t

rHF,23' lKH.

Resolation of alcohols.t The reage estersof I alcoholivia the diastereometric phoratesgenerallyhave high melting p crystallizationor chromatography.

' D. KappesandH. Gerlach,Org.Syn..srbr

Carnphorquinone,

4

' E. J. Corey and P. Carpino,,42 Soc., 111, 5472 (1989).

o

from Aldrich. Optically active homoallylic alcrlcl from ( - )-l in five steps,adds to aldeb alcoholsin 88-96Voee. CH"- -CH"

so2cH,

T

.l\-ir D--!, cH, z

o

.L.",c":c R=cz& =C(CHr\

=q&

I l 989)

.': :hc aglvcone (4) of pseul-'.::r nal (1) and (CH3)3SiOTf ':..rrsvlicalcohol to give 3 F:

ll i il

Camphanoylchloride(1)' Supplier:Aldrich' Preparationfrom camPhoricacid:

I

I ..CH,

V'\// ,tAo

i\H. THF, 23'

l\-t", /l\cooH

r)PCr5 2)B'z , ffio

!1.o

l) NACOJ, H2O 2)' SOCbu

o

68%

Acoo"

.w"

cH3-Y cH3

CH,

CH,

cH3-_ cH3

t&6

(+)

(-) -1, m.P.71", oo -1 8'

(m.p.215,%-20")

Resolutiono! alcohols.t The reagentis widely usedfor resolutionof chiral estersof ( - )-camphoricacidformedfrom 1' Camalcoholsvia the diastereometric points and can be resolvedby fractional melting phoratesgenerallyhave high crystallizationor chromatography. (1989)' , Org. Syn.,submitted D. KappesandH. Gerlach cH3

cH3\ t

\

n

camphorquinone, (lY"

(-)-1. Both (+)- and (-)-1 are available

kf_._[ cH, .b from Aldrich. prepared Opticatly active homoatlylic atcohols'r The allylboranereagent2' troml-;-rinfivesteps,addstoaldehydestogiveopticallyactivehomoallylic alcoholsin 88-96Voee.

gH

SO"CH.

t -

RcHo

N

t R.,,,$CH,

,BCHTCH:cH, R=QHs =c(cHJ3 =CeHs

92Vo 801o glVa

92Vo ee 884o ee 88Voee

c 6E

Camphor-l0-sulfonYlchloride

These are the first reagentsknor enolatesof carbonyl compounds'Thc reaction of ( - )-1 with a p-keto eset

r M T. Reetz and T. Zierke, Chem' Ind',663 (1988)'

Camphor-l0-sulfonicacid. The chiral tridendate Asymmetricaddition of (CHr:CH\2Zn to aldehydes' enantioselective highly effects acid, ligandi, derivedfrom ( + )-camphor-1O-sulfonic additionofR,Zntoataelyaes.Significantly'evendivinylzincaddstoaryland in 82-967oee' aliphaticaldehydesto furnish (R)-allylicalcohols CHr-,zCHr l\

o

l\ 0)rYtq \J E. Differding and R W' l-ang' Tctrcl*l

r\>

l-')
(Cerbonyl)chlorobis(triphery$r1| Hydrostannation ol l'alkYs'r terminal alkYnesto form a l: I mirtl ever, use of this rhodium catdYsr r as the major prc 3-alkenylstannanes

/ -Nctt"ct1N1cur), / ' CTL 1

+1cq:sg&n J-+"?Xijrl,iil: cH3(cH')4cHo (R), >96%er lW.oppolzerandR'N.Radinov'TetrahedronLetters,29,5645(1988).

Camphor-l0'sulfonYl chloride' Enantioselectivefluorination.TheN-fluorosultamsland2areprepared chloride' from the imine available from (+)-camphor-10-sulfonyl

I l) cH3Mslrcucl | 2) F/ro%)

cHrlcHr

r\>

ryf rgj r.", (+)-2,m.p.151-154o

(-)-1,m.P.112-114o

RC=CH

+ BurSnH 4

R = ccHs R = AcOCHT R=s(cHil

913 ?lt 9lt

K. Kikukawa,H' Umekawa,F ftdl

Crrbonylhydridotris(tripherylf q Regi oseIecti ve hYdrofottY ld it (Z)-t-butyldiphenylsilylalken of essc is group silyl bulky A rionI).

(r)

t-BuPh,Si -

\J

Br

This reaction can be used to obtail

( (ID &si-

/

Carbonylhydridotris(triphenylphosphine)rhodium

6)

These are the first reagentsknown to effect enantioselectivefluorination of is observedin the enolatesof carbonylcompounds.The highestenantioselectivity reactionof (-)-1 with a B-ketoester(equationI). , Thc chiral tridendate s hrghh enantioselective r.zrnc addsto arYl and ! re.

o (r) (

a

t) N!H,cthq

ii

il

zit->i ,

,A.-coocr4



%$J

e

"cooc'u'

\--'/

00% ee) I E. Differding 6087(1988)' Letters,29' andR. W. Lang,Tetrahedron ClRh(CO)[P(C.H5)3],(1)' (Carbonyl)chlorobis(triphenylphosphine)rhodium, adds spontaneouslyto hydride Tributyltin Hydrostannation of l-alkynes.r Howtrans-l-alkenylstannanes. and of crsmixture terminalalkynesto form a 1:1 provides (2, galvinoxyl) inhibitor radical and a ever, use of this rhodium catalyst as the major product. 2-alkenylstannanes ..-CH:CH,

-,cHr1.cH, , >96q e€ 5 -,\rl.

r l . i n d 2 a r e prepared

ii+ Rc=cH + BurSnH R = CcHs R = AcOCHz R = Si(CHJc

R )c:cHr* BurSn

RCH:CHSnBur 7E:22 73:27 16:24

99% 7l% 9L%

(W = 9l:9) (E > 99) (E, |ffiVo)

Chem.Letlers'881(1988)' F. Wada,andT' Matsuda, H. Umekawa, K. Kikukawa,

;h.,,rrde.

,\F

RhH(CO)[P(C,H,)3]. (l)' Cerbonylhydridotris(triphenylphosphine)rhodium, hydroformylation.t The rhodium-catalyzedhydroformylation Regioselective is an excellentroute to p-silyl aldehydes(equaof (Z)-r-butyldiphenylsilylalkenes tion I). A bulky silyl group is essentialfor this regiocontrol.

tH

(r)

sulo;*

,si t-BuPhzSi

,Bu +

6ffi

CHO

|

CHO

-L -

+ RTSiCHCH RTSiCHTCHBu ,Bu 96:4

This reactioncan be usedto obtain aldols(equationII).

(ID

&si. -

oH

\J..",i'

cHo

R3sicH,J"q".", ' ,r* --------l;-

+

(98:2)

70

Cerium(IV) smmonium nitrate

Hydroformylationofthel,2-bisilylalkene2isaccompaniedbyBrookerearrangement to provide a silyl enol ether (3)' R.Si

-si1cH,;,

**

R3SiCH2r Y

2

Oxidative demethylation of tetranet with CA 1,4,5,S-tetramethoxynaphthalenes electron is an R If products (equation I).

/OSi(CH')3

3

'M.M.Doyle,W.R.Jackson,andP'Perlmutter'TetrahedronLetters'30'233(1989)' Cerium(IV) amonium nitrate (CAN)' of CAN for oxidativeaddition Addition of l,!'diones to vinyl acetate't Use ofcarbonylcompoundstoalkeneshasbeenreportedinseveralpatents.Themethod can be extendedto synthesisof acyl or alkoxycarbonylfurans' O ll

O ii

JCOCH3 / \

cH,cN__ r)cAN, ___

cHYcH,+

cHr:csoRc4Ej4'

o o il il nAAocrH,+

JcooczHs -ll cHr:cHoAc-;- (o2\

n.o4elcn,

mainly;but if R is an electron-withdrarin of quinonesare stableto CAN, but can t or with AICL.

^

ASO-.Oi lGl

o

o

a\ I

I,R=H R = CHzOH R=CHO

I

+CH,CH:CHOAc-30%+

/\-_ir'"'

cH:

cHfo

substitutedo-position.Thismethodissuperiortoanearlieroneusingl,_Cu(oAc), in HOAc (10,211). L, CAN cH,oH, ?5' $Vo

r r O A r''-9tN Y ll ll -+ BuecHrI PrcHccH3+ eodcH" ' t v w l 74:26

sz.t

o/

Yieldsarelowerwithpropenylacetatethanwithvinylacetate,butevenso,the (last example)' reactionis a viable route to monoterpeneevodone g-Iodinationofketones.zIodineincombinationwithCANconvertsketones with substitutionat the more into c-iodo ketonesat 25-50" in HOAc or CH'OH'

| I

53*

R=H R = CHzOH

Atot

3.W,

R = cHo

43t

4-Oxo aldehydedimethyl acctols'' and CAN resultsin a radical speciesthe svlethyl)ketone. Solvolysisin methano aldehyde.Similarreactionsof ketones$t orovide1,4-diketones(6' 356)' Sulfuxides.s Oxidation of sulfidcsr equiv.)in CH,C!/HrO catalyzedby Bu.l type rearrangementdoes not occur und

Cerium(IV) ammoniumnitnte

xJ mpaniedby Brooke rearrange-

Oxidative demethylation of tetramethoxynaphthalenes.sDemethylation of 1,4,5,8-tetramethoxynaphthalenes with CAN (in HrO) can lead to two types of products(equationI). If R is an electron-releasing group, quinone2 is formed

osi(cH3)3

\=J

R

lc'-

cAN cHlcN, 25' -----+,

: , ' , , tL e u e r s , 3 0 , 2(3139 8 9 ) .

t ..- : CAN for oxidativeaddition }(:: j .:r:er'€t?lpatents.The method Ea:-.rrliurans.

_JcocH3

c-\ lt

//

.-.J!r,

//

\\ \\

;.--------.--eco46^cu,

't 'l}Vo 'l5Vo

I,R=H R = CHzOH R=CHO

3 13Vo 857o

group,quinone3 is formed.Both types mainly;but if R is an electron-withdrawing of quinonesare stableto CAN, but can be demethylatedwith AgO-407o HNO. or with AlCl,. OH

-TCoXrHt )\

7l

./

^ A8O-40% HNO3 Z +

o

'

l

/-'r-----..cH..

l

l

l

R=H R = CHzOH

53Vo 52Vo

at'^'60/ rrl acetate,but evenso, the .-tslexample). r qith CAN convertsketones ',\rrhsubstitutionat the more f rrlier oneusingIr-Cu(OAc)2

Alcl3 cHrclz 3

R = CHO

) l

fii

l -

o l

BuCCHtl

,

43Va

4-Oxo aldehydedimethyl acetals.4 The reactionof a ketonewith vinyl acetate .rndCAN resultsin a radicalspeciesthat is convertedto an a-(2-acetoxy-2-nitro.r'lethyl)ketone. Solvolysisin methanolresultsin the dimethyl acetalof a 4-oxo rldehyde.Similarreactionsof ketoneswith isopropenylacetateandMn(III) acetate (6, 356). provide1,4-diketones Sulfoxides.s Oxidation of sulfidesto sulfoxidescan be effectedwith CAN (2 equiv.)in CH'CI,/H,O catalyzedbyBurNBr at 25"(90-100Voyields).A Pummererdoesnot occurunder theseconditions. :\pe rearrangement

Cerium(III) chloride

CH2OH

*H,, . cH,:s11eo. A L&.",Kd o u,r, f.",o", cHrcH(ocH3)'

Puc,Bt(so.)! |

*or--% + CeCl"

metal catalyst.In fact, Ni(CN)r is inr affectsthe rate of reaction. Tetrabuql: methylammoniumbromide are the rnos N(C

I E. Baciocchiand R. Ruzziconi,Syn. Comm.,18, 1841(1988). 2 C. A. Horiuchi and S. Kiji, Chem.Letters,3l (1988). 3Y. Tanoueand A. Terada,Bull. Chem.Soc.lapan,61' 2039(1988). . E. Baciocchiand R. Ruzziconi,J. Org.,51, 1645(1986);Org. Syr., submitted(1989). 5 E. Baciocchi,A. Pi€rmattei,and R. Ruzziconi,SYn.Comm.,18' 2167(1988)'

Cerium(III) chloride. Functionalized allylsilanes.l A Grignard reagent when activated by CeCl. reacts with esters,r ester acetals or lactones2to give functionalized allylsilanes'

? " 1

'8Pi::i{&:', coH,cH:cHCooc2H5 L ,, ^,,:CHCICHzSi(CHr)rlrl LC6H5CH

c6H5cH2cl * 69

crdlr

B. A. Narayananand W. H. Bunnellc. Ic syr?.,submitted1988. :T. V. Lee. J. R. Porter, and F. S. Rodco. ' R. Oi and S. Tanenaka,Chem. Lettcn. ll" ' L Amer and H. Alper, Am. Soc.,lll. 9g?

Cerium(IV) sulfate, Ce(SO)r. Malonyl radicals.r Thiophenes a rreated with a dialkyl malonate and ceri ro involve oxidative generation of malo tO-85Vo.

9l% | SiOz' -HOS(CH3)3

' ""^

il'

:CHCCH2Si(CH3)3 C.HTCH

.",/)+

cH,(coocHJ'=

z=O, S

(cH3LSicItMect+ o\

CH"

ll'

./> )

r*'

HocH,(cH,),ccH,si(cH3)3

L. M. Weinstock,E. Corley, N. L. Abr.. n.2627 (1988).

+ CcCl3 747o oxygenationof ru-hydroxybenzyl A{HrOH'--> A|CHO,s Platinum-catalyzed presentin traces'the further is also If CeCl: 3. 2 and alcohol(1) givesa mixtureof possibly by acetalizationof 2. depressed, oxidationof 2 to 3 is markedly can be effectedwith cobalt reaction This Carbonylation of benzyl chloride.a conditions.CeCl promotes phase-transfer under carbonylor a palladium(0)catalyst nickel(Il) cyanideas the use of permits the also processand this phase--transfer

Cesiumcarbonate. Wittig-Horner reactions.t Ttrc rc (1) with aldehy&sI methylphosphonate yields when NaH is t poor gives and proceed readily at (F. $opropyl alcohol r synthesisof o-erythro-C's-sphingcir

Cesiumcerbonate

.-'"':l:,i -..i

""-q;,,cuoH

+ CeCl,

'\\ l.

| '- ,::nt uhen activatedbY CeCl. allylsilanes. r t .- :unctionalized

o l

H

l l

il:CHClCHzSitCHr)Jrl

3 (18Eo\ lVo

c6H5cH2cl * 66 -c'edaH'fBi

c6H5cH2cooH

B. A. Narayananand w. H. Bunnelle, TetrahedronLetters,g.626r (19g7):idem, org. S_yn., submitted1988. 'T. V. Lee, J. R. Porter,and F. S. Roden, Tetrahedron Leuers,29,5009(l9gg). R. Oi and S. Tanenaka,Chem.Leuers,ll15 (1988). '1. Amer and H. Alper, Am. Soc.,lll,9Zj (1989).

Cerium(IV) sulfate, Ce(SOo)r. Malonyl radicals.r Thiophenes and furans undergo substitution at c, when ireated with a dialkyl malonate and ceric sulfate at 25.. The reaction is considered :o involve oxidative generation of malonyl radicals by the cerium salt. yields are tt)-85Vo.

-Hos(cH3)3

CH"

il-

It{.C t'l :CHCCHTSi(CH3)3 CH"

cli

2 (7rEo) 88Vo

cooH

Ni(CN)r,CeCl'

F r 6l - l'r ( 1988). r rrr. Srr., submitted(1989) I -.' . lt.2l67 (1988). r':"r

n.,.'.

""C-t"o*Ho

metal catalyst.In fact, Ni(cN), is inactivein the absenceof cecl,, which also affectsthe rate of reaction.Tetrabutylammoniumhydrogensulfateand cetyltrimethylammoniumbromide are the most efficientphase-transfer catalysts.

L-

ll'

cH10H. H'O

cHroH. A

/n'.--cHrcH(ocH3),

ll-:

PVC,Biz(sOrb

^

+u.+

il'

cH.):ccHrsi(cH3)3

EJ rrqenation of rn-hydroxybenzyl I l\ -,.\,,presentin traces,the further is:^ : .1 acetalizationof2. r.i.i:,rn can be effectedwith cobalt r!:.:^-ir'r conditions.CeCl, promotes lht ':.c' of nickel(Il) cyanide as the

ll

cH/{-)

\

cc(soah. cHloHr.r,o . $ffi4 /tr + cH,(coocH,l, "",4r\cH,(coocH3),

z = O ,S L M. Weinstock, E. Corley,N. L. Abramson, A. O. King,andS. Karady,Heterocycles, n.2627 (1988't.

Ccsiumcarbonate. Wittig-Horner reactions.t The reaction of 1,2-O-isoproylidene-o-glyceroylnethylphosphonate (l) with aldehydesfailswhenN(CHrCH3).-LiCIis usedasbase rnd gives poor yields when NaH is used. However, reactionswith CsrCO, in sopropyl alcohol proceedreadily at 0". This Wittig-Horner reaction was used for r svnthesisof o-erythro-C,r-sphingosine (2).

74

Cesium carbonrte

.CH.

cH3+( 9

(cHphsq (cHrhc.

cs,co,

?

"ff

* c,3H2?cHo $1o"",y, #

o

H

O

O

C

Iqco3,64 hI. CsrCOr,15 hr.

I

H 3 c ,CH' < _9 .

r/ l O.-A.,,1,,C13H27

ll o

NH, s"qa srcps, Ho-.,\r1.,CnHzr

r

o

H

I t4c 94*

I T. Yamanoi,T. Akiyama, E. Ishida,H. Ab€. I 335(1989). r J.-F. Lavall6e and P. Deslongchamps,Tetrahcd r R. T. Winters,A..D. Sercel,and H. D. H. Slx

2 Anionic polycyclization to a steroid.2 When treated with CsrCO., 2-meth(1) and the Nazarovreagent2 undergoa Michael reoxycarbonylcyclohexenone actionfollowedby aldol condensation to give a tetracyclicadduct(3), which under(TsOH) to give the steroidderivative4 in 477ooverall goesdecarboalkoxylation yield.

I). Desilylation of I with CsF and L8-cro*n

$i(qrl ),

o

tl //'\.8

l

Cesium fluoride. 2-Aza-L,3-dienes.t A new route to th + 2lcycloadditions involves protodesilyb [2 as 1, available in several steps from propar!

l

l

I, E = COzCHT

+ cooc(cH3)3 )

(l) H2NCH,C=CH +

Cs2CQ, cHch,25'

nrNSHCH:Ot

cooc(cH3)3 3 lr* | r.ou, c5rq,,

ovqal

J

A

resultsin (E,E)- and (E,Z)-2 in the rario ol increasedthe (E,E)/(E,Z) ratio approach

4

Alkylation of cesiumphenolates.s Alkylation of hydroxylated 9,L0-anthraquinonescan be accomplished fairly readily by alkylationof cesiumphenolates.

Crotylization of RCHO.' (E)- and ( hydesin the presenceof CsF to give anarespectively, with high diastereoselectirir

Cesium fluoride

CI

o

HO

75'

(cH3ohs02 (CHrbC . -=O >

H

O

O

C

rqco3,64h. 15hr. CsrCO,,

fH' o--r\.,1zc"H' I OH

I 84Vo 947o

' T. Yamanoi, T. Akiyama,E. Ishida'H. Abe, M' Amemiya'andT Inazu'Chem'Letters' 33s(1989). : J.-F.Lavall6e Letters'29'6033(1988)' Tetrahedron andP. Deslongchamps, 712(1988) 'R. T. Winters, Synthesis' andH. D. H. Showalter, A. D. Sercel,

7

teJ \\lth CsrCO.,2-methr ! undergoa Michael rer rJJuct (3), whichundercrrr.rtive4 in 477ooverall

Cesiumfluoride. 2-Aza-lr3-dienes.tA new route to theseusefulsubstratesfor [4 + 2]- and such of N-1-triethylsilylallylimines involvesprotodesilylation [2 + 2lcycloadditions (equation yield as 1, availablein severalstepsfrom propargylaminein about 30Vo of water I). Desilvlationof I with CsF and 18-crown-6in THF containinga trace si(c2H5)3 (t) HrNCHrc=cH #

4Nlncn:cH,

c'H'cHo ' cuHrcH:N CHCH:CHz si(c2H5)3

o

r, (8,rN%) I csF. l8-qown-6 80% rHF (H"o) |

.-+ | rsox, ceite'

r.au

I

A

crHryr: I-

q\ -CH,

H 2' (E' EtE'Z) = 6: I

of wateris resultsin (E,E)- and (E,z)-z in the ratio of 6:1. As the concentration unity' the (E,E)/(E ,Z) ratio approaches rncreased

{ f nr JroxYlated9,10-anthralr..: ,rf cesiumPhenolates'

crotylization of RCHO.' (E)- and (Z)-crotyltrifluorosilanesadd to aldealcohols, hrdes in the presenceof csF to give anti- and syn-p-methylhomoallyl with high diastereoselectivity. respectively,

76

Cesium fluoroxYsulfate

o'H !

CH"

RcHo+'*--r,r"

'

#*Tc*r,

I, C2H5OAc

BucH:cHz-#

BucH-c$

OSO,-C

cH.

(98-9:2-l)

gH crF

RCHO+ CUr^SiR

77-96%

BuCH-CH

I oso:o

r R-

CH, (90-D:10-1)

a,^1.a,OSO,-Cs'

I 'S.-F.Chen,E. Ho, andP.S. Mariano, (1988)' Tetrahedron,44,7013 2M. Kira,T. Hino,andH. Sakurai,Tetrahedron (1989)' Letters,30,1099

\.r'

l l + r - - . . . . r 1| \

cH3cN,0o crHroAc

Cesiumfl uoride-18'Crown'6. Fluorodcstannylation. BurNF is the most reactivesourceof F-, but is difficult Harpp and Gingras' prefer csF to obtain anhydrous.For fluorodestannylation, This reagentcombineswith diorganotin with a catalyticamount of 1.8-crown-6. oxides,sulfides,or selenidesto liberate the correspondinganion, which can be alkylatedto give ethers,sulfides,or selenides. (BurSn)rO+ 2BzlBr ff

@tr)rO + 2Bu'SnF

[(cHr)rSn]rs + 2CHr(CHr)rB,#

t(cH3(cHr)5lrs+ 2(CHr)rSnF

catalystfor conversion is alsoan effectivesolid-liquidphase-transfer 18-Crown-6 of benzylbromideto benzylfluoridewith CsF.2 rD. N. HarppandM. Gingras, (1988)' Am. \oc.,1f0,7737 2M. GingrasandD. N. Harpp,Tetrahedron 4669(1988)' Letters,29'

Cesium fluoroxysulfate, CsSO,OF (1), 10, 84-85. Caution: This hypofluorite is explosive. Addition to alkenes. Although this reagenthasbeen studiedmainly for elecvic-fluoroalkyl trophilic fluorination,rit does add to alkenesto give cls-selective The adductscan be addition. for azfi-Markovnikov preference sulfateswith some (CrH5)3O'BFq-'2 with by reaction ethoxysulfates convertedinto fluoro

F cis-2 529o 30%

' E. H. Appelman, andR. C. Tho L. J. Basile, : N. S.Zefirov,V. V. Zhdankin, A. S.Koz'mrn '14.65OJ(t andS. V. Romaniko,Tetrahedron,

Cetyltrimethylammoniumbromide (CTAB Williamson synthesisof phenyl al\I t alkyl halidesin 20VoaqueousNaOH cont to form phenolicethersin 85-9'lVo vieldCTAB. This procedureis not usefulfor prc and alkyl halides.Instead,the alkyl chlond are heatedin THF at 70"with NaOH (l o CTAS

+ CrHrBr C6H5OH # (CH3)TCHOH + n-CrH,,Ct{ 4, 6677(19881. B. Jur5i6,Tetrahedron,

Cetyltrimethylammoniumchromele, n-C. obtainedas a yellow-orangesolid b1'rcrt rum bromide in water at 25". lt can be u ketonesin an aqueoussolution.Howere

Cetyltrimethytammoniumbromide

OH Crf :-K

- -,A.--rA. I |

I, C2H5OAC

BuCH:CHz-#G-

e- - H -a .

BuCH-CHrF+ BuCHF-CHroSorCs* osor-Cs*1:2

cH3 (9E-99 :2- l)

soia| 1crxr;.o'nro-

*

9H

k-T"rrcH3

B uCH-CH,F

+ BuCFIF-CHTOSO2OC2H'

oso2ocrH5

t 9 0 - 9 9l:0 - l )

f-\ It- ll Lt .'

-ttl-1

I (1988).

a,1-oSo,-Cs. ll+l-------+l

- { f . 1 0 9 9( 1 9 8 9 ) .

I. 28- SnF IrCil CH,),lrS + 2(CHr)rSnF

+ffans_2

cis-2 cH3cN,0o crHroAc

ll :: j.:r\e sourceof F-, but is difficult Dr. iirrpp and Gingras' prefer CsF I r. j!.:lt combineswith diorganotin c. -':.r'ondinganion,which can be

|

\-t'

52Vo 30Vo

30Vo 20Vo

E. H. Appelman, L. J. Basile, R C Thompson, Am. ioc..f01,3384 (1979). ' N. S.Zefirov, 1! V. V. Zhdankin, A. S.Koz,min, A. a. FainzitUerg, A. A. Cakil,e. I. Ugrak, andS. V. Romaniko, Tetahedron,44,6505 (19gg). Cetyltrimethylammonium bromide (CTAB). williamson synthesisof phenyr alkyt and diarkyl ethen.t phenors react with alkyl halidesin 20voaqueousNaoH containingl equiv. of this surfactantat g0" lo form phenolicethersin g5-g7% yield. There is no reactionin the absenceof crAB. This procedureis not usefulfor preparationof diatkylethersfrom arcohols and alkyl halides.Instead,the alkyt chloride,alcohol, a traceof water, and crAB are heatedin THF at 70. with NaOH (2 equiv.).

pa:i. r .: rrnsfer catalyst for conversion

F

r .-.

C6H5OH + CrHrBra1HI8+ C6H5OC2H5

I 19:.69(l9gg).

(CH3)rCHOH * n-crn,,ctJIffL\, a-\<

Caution: This hypofluorite is

3r1li:r been studied mainly for elecIt' ir\€ cis-selectiveulc-fluoro alkyl mri.'i addition. The adducts can be oc * rth (C:H5)3O*BF4-.,

(CH,)rCHoCrH,, -n

B. Jur5ii,Tetrahedron, U,6677 ,198g\. Cetyltrimethylammonium chromate,n_C,uH.,frH1CH.).CrO. (1). This oxidant is obtainedas a yellow-orangesoridby reactionof cro. with cetyltrimethylammonrum bromidein water at25'. rt can be usedto oxidize arcoholsto ardehydes or ketonesin an aqueoussolution. However, it is not necessary to isolatethe sart

7E

p-Chlorobis(cyclopenirlryf

l-Chloroalkylphenylsulfoxides

sinceessentiallythe same yields are obtainedby oxidationswith CrO, in H2O/ bromideas surfactant.l CHCI, with cetyltrimethylammonium tB. Jurii6,Synthesis,868 (1988).

X-

in ethanol liberatesa free hydroxy grouP ' formation of the cyclic ether 3. A similar sr cyclicethers(equationII).

o Chloramine-T(1). 2-Isoxazolines.l Reaction of aldoximeswith chloramine-T generatesnitrile oxides,which can be trappedby alkenesto give 2-isoxazolines. l) l. c2HjoH

tl

(rI) c6H5scHCl

+ C.HTCHO

I

(cHTLOTHP

^ -N.

prcH:NoH"#t"

i

)n

C,H,H

"'.... ... .,^o*-o" _*t",ft*ro !#(c",

\,,\ftH"'n CH,

T. Satoh,K. Iwamoto,A. Sugimoto, andK. Yaa ( ie88).

I A. Hassnerand K. M. L. Rai, Syntlrestt,57 (1989).

o ll

l-Chloroalkylphenylsulfoxides, C6H5SCHCI (1). R to 2-acyl cyclic ethersis basedon an intramonew route Cyclic ethers.r A with a nucleophileas outlinedin equation sulfoxides lecularreactionof c,B-epoxy with pyridiniump-toluenesulfonate 2 sulfoxide I. Thus reactionof the c,B-epoxy O

I)LDA

O

ll ll ll**cH2)acHo 3)oH> cuH,S\/q (r) c6H5ScHCl I '(CHr)4OTHP Bzl Bzl' 2 czH5oH *" I li?#;siic6lrqso3-'

(dinethyldr p-Chlorobis(cyclopentadienyl) reagent). Addition to nitriles.t Reaction of Cp1 tanacyclobutane L, with pivalonitrileforms further reactionwith a nitrile forms eventua on acidolysisprovidesthe B-ketoenamine3.

clrrlc(CH,),

-+

tCp,Ti-Cgl

o:\

zC(ffi'\

CprTiClr+ ) H'N{

o

tl

BzlC- O_

t

\-/ 3

l

'C(CH!).

3 K. M. Doxsee andJ. B. Farahi, Am. Soc..llf.

;r-Chlorobis(cyclopentadienylXdimethylaluminum)-p-methylenetitanium

t r .,rrdationswith CrO, in H2O/ a:.urtactant.r

in ethanol liberatesa free hydroxy group which cleavesthe epoxy group with formation of the cyclic ether 3. A similar strategycan be usedto prepare.3-oxo cyclicethers(equationII).

o

o

tl

tl

)ti: . rritrramine-Tgeneratesnitrile r l- .,,razolines.

79

+ C.HTCHO-----+ C6H5S\A

0I) c6H5scHcl I

(cHJ3OTFTP

rFfolcHrlrncuH,

-\

60% PyNH. CH3C6HaSO3-, C2H5oH J

\-n

o

L""'-'J

tl /"',tcuH'

*--Y-\o

I

#.",

I

!.o T. Satoh, K. Iwamoto, A. Sugimoto, andK. Yamakawa, Bull.Chem.Soc. Japan,6l,2109 ( 1988).

l r

dr. .:icrs is basedon an intramoou- :.'nhileasoutlinedin equation l::: rr ndiniump-toluenesulfonate

p'chlorobis(cyclopentadienyl)(dimethylaluminum)-p-methylenetitanium (Tebbe reagent). Addition to nitriles.t Reactionof CprTi:CHr, readily formed from the titanacyclobutane 1, with pivalonitrile forms the [2 + 2lcycloadducta, which on further reactionwith a nitrile forms eventuallya new metallacycle 2. This product on acidolysisprovidesthe p:keto enamine3. ^ -.4. cp,r(

\ ')_c(CH,), /

o

l^ (cH, (cH3bccN ] -'N' laort(-)-c(cH3)j

-------r [cp,Ti:eHr1

L

I

:

a

-'i{. T.OTHP (cH3)3ccN

:

| Y

l ix . cxrcun sor-, c2H5oH . -c6HJsoH

'' n

o:\

/c(cH3)3

CprTiClr+ ) HrN-{

i---o\

I -1

-

l)Hcl

/c(cH3)3

N< /

2)H^o

\

Cp"Ti --

'c(cH3)3

3 K. M. Doxseeand J. B. Farahi,Ant. Soc.,110.7239(1988).

\

)

//

N-<'c1cH,;, H

,

I I

r

80

Chlorobis(cyclopentrdienyl)hydddozirconium

(Schwartzreagent, 1)' Chlorobis(cyclopentadienyl)hydridozirconium pure 1,3-dienesinvolves isomerically Cross-couplingof alkynes.r A route to to hydrozirconationof an alkyne followed by conversion the alkyne complex3, 4. Treatment which coupleswith a secondalkyneto give a metallacyclopentadiene (>97Vo). isomer single as a of 4 with dilute acid providesthe diene 5, usually Overall yieldsare in the range53-80Vo.

1S. L. Buchwaldand R. B. Nielsen.Am. fu. rS. L. Buchwald,Q. Fang,and S. M. King. ,

Chlorobis(cyclopentadienyl)methylztuc

Pynolesl This zirconocenereactsu amine,RCH,N(Li)Si(CH,),, to form 2. r with variousallynesto form azametallac neednot be isolated,reactwith carbonn

)

Ri

*'J/

.R'

i(cH3)3THF. -?'

l-"* T

Rr

X/*' |

V*..ir9l- cp,4 r ) *

.

I + RCHrN-Li

R3c'cRa -rr(_"

' R2

4

Rt

H Butenolides.2 Addition of the Schwartz reagent to a protected propargylic alcohol (2) followed by carbonylationprovidesan acyl zirconocenecomplex(3). This is not isolatedbut treatediz silu with iodine to provide an intermediate(a) butenolide(4). Optically activesubstratesundergo that cyclizesto a 3,S-disubstituted purity. optical loss of with no this sequence

9siR3 I ll:., cH3c=c^curcu, lBcpr( ee),R = CcHs 2 (9O1o

o\ A Cl

.1cH3 Y"

,,,

,oR3

'CH2CH3

.cH"

\\*tT H

r

.

4

M. W. Wannamaker. andf, S. L. Buckwald,

I

a"r.."_{ i l o

[ , \ r o *\.",."1 'l-

L

c

highestwhenthe reactionis carriedout rn at 25oor of 4-A molecularsieves.The rq pyrrolesrather than pyrrolinones.Even i provide2-substitutedpyrroles.1-Alklner The yield is low in a reactionwith a l. iactors.

3

[o

-crt

\1

\a"^a",

4 (907oee)

I|I) Chlorobis(cyclopentadienyl)titanion( Cyclization of epoxy alkcnes.z Thc i equiv. of CprTiCl in THF resultsin c1 :eactionis compatiblewith keto and nitr

Chlorobis(cyclopentrdienyl)titanium(III)

lucr:z reagent,L). involves Brri;..r pure 1,3-dienes 3, complex !f\r.\:r !o the alkyne Treatment 4. llr.\ . irrpentadiene fl,. :- a singleisomer (>97Vo)-

I S. L. Buchwaldand R. B. Nielsen.Am. \oc..111.2870(1989). tS. L. Buchwald, Fang,and S. M. King,Tetrahedron (1988). Leuers,29,3445 Q.

Chlorobis(cyclopentadienyl)methylzirconiu-, cpTr(CH'

(1).

PyrrolesJ This zirconocenereactsin THF with a lithio trimethylsilylprimary amine,RCHrN(Li)Si(CH,)r,to form 2, which is not isolatedbut allowedto react with variousalkynesto form azametallacyclopentenes 3. Thesemetallacycles, which neednot be isolated,reactwith carbonmonoxideto affordpyrroles4. Yields are

RI

:.opS-*L .CH,

)

%-[.ry**]

s(cH.)"

I

l-"*

t - -

I + RCH"I\,I-Li

,

J-.{.o,o(o

I

I

n'c=cR"

3 Rt

Rt

lt \

!ai.:r: to a ProtectedProPargYlic li. :i\l zirconocenecomPlex(3). bc :,' providean intermediate(a) O::rcallv activesubstratesundergo

OR

4

\*t* H 4

Rt

R2

#

CO, THF NH,CI or 4AI\,!S 30-10% ovqdl

\={ / \ cprZt.*AR

I

si(cH3)l 3

highestwhenthe reactionis carriedout in THF in the presenceof NH.CI (3 equiv.) at 25oor of 4-A molecularsieves.The report includesa rationalefor formationof rather than pyrrolinones.Even acetylenecan be usedin this synthesisto o.v"rroles provide2-substitutedpyrroles.1-Alkynesreactto form 2,4-disubstituted pyrroles. The yield is low in a reactionwith a 1-trimethylsilyl-1-alkyne becauseof steric factors.

12-

bx cH,

S.L. Buckwald, M. W. Wannamaker, andB. T. Watson, Am. Soc..llf,776(1989).

i:.J

a"raa_{ .-----, ll O 55 Ya",a", 4 (90Voee)

Chlorobis(cyclopentadienyl)titanium(III), CprTiCl. Prepararion.' Cyclization of epoxyalkenes.2 The reaction of 6,e-unsaturatedepoxideswith i equiv. of CprTiCl in THF resultsin cyclizationto cyclopentanemethanols. The :eactionis compatiblewith keto and nitrile groupsbut not aldehydegroups.

Chlorodicrrbonylrhodium(I) dimer

fr, rio-1-'cHz'

{

----cr

a""'

'V'

"4"

*I:.

(E = COOqHs)

f"o'"'''

c*ltrans = 8 5 :1 5

.",if,

expansionof the optically pure azind 937o yield. Carbonylationof racen l-men [CODRhCI],in the presenceof chemicalyields.This asymmetricindu S.Calet,F. Urso,andH. AlPer.Am' h

CIB(C,H.): ( I )' Chlorodiethylborane, AUilic diethYlboranes.t These t and 2-alkenesby metalla cycloalkenes lowedby reactionwith 1. The producr alcohols(3), which can be converted

CH,

r1KcH2s(cH3b 2) l. ethq

HO1

t

/CH'

88%

H I t) 2CDrTiCl

63% lztr., HOI

,,M.. \ t

w

(endolexo = 9:l)

..'CH't

)

H

rL. E. Manzer, (1982)' Inorg.Synth.,2l,84 8561(1988)' 'w. e. Nug.ntanOi' V. RajanBabu' Am' Soc',110' Chlorodicarbonylrhodium(I)dimer' of aziridinesto Carbonylation of aziridines(12, Il2)'t This ring expansion is substituted ring the when only p-lactamscatalyredby [(CO)rRhCl],is successful group' The t-butyl a by by an aryl group and when the nittog"n is substituted C^H.

CuHt

\-

'N'

I

c(cH)3 (s)-1

*co$' "n

)_l ohN-c(crtr),

(s)-2

Chem.2 J. Organomet. \f. Zaidlewicz, Generatedfrom Hg[CH,Si(CH,).1;and

o il

c-Chloroethyl chloroformate' CICI Review. Use of chloroformat Braun reaction)has been reviewed rction.

c-Chloroethyl chloroformate

Cp,

-ttH" f.,,,",

t'"HricrcP'

83

expansionof the optically pure aziridineL resultsin the pure (S)-B-lactam2 in 93% yield. Carbonylationof racemic 1 catalyzedby either [(CO),RhCl], or ICODRhCI],in the presenceof /-mentholresultsin opticallypure (S)-2in25-30Vo chemicalyields.This asymmetricinductionresultsfrom kinetic resolution. I S.Calet,F. Urso,andH. Alper,Am. Soc.,Ul, 931(1989). Chlorodiethylborane, CIB(CrH,),(1). Allylic diethylboranes.t Theseboranes(2) can be preparedfrom 1-methylcycloalkenes and 2-alkenesby metallationwith trimethylsilylmethylpotassium2 followedby reactionwith 1..The productsreactwith acetaldehyde to form homoallylic alcohols(3), which can be convertedinto ct,B-and B,1-unsaturated ketones.

H OH

r^.a t l

CHp(CrHs),

r) cHrcHo 2) OH 12% ovarll

\-/

t

t

CH"

l

cHffi \-J

,

3 ro*Jrocor,rr O

(/

'-c1cHr;, S'-1

CH,

v)#

M. Zaidlewicz, J. Organomet. Chem.,293,139(1985);Synthesis,70l (1988) Generatedfrom Hg[CH,Si(CH.).],and potassium.

o tl

\_

O

*AA ^.-."44 (,

i l ." \ \ ) .

rnr erpansionof aziridinesto llr *hen the ring is substituted NtcJ br a ,-butylgrouP.The

CH"

c-Chforoethyl chloroformate, CICOCHCIC\, L2,IL2-I13. Review. Use of chloroformates(carbonochloridates) for N-alkylation (von Braunreaction)has beenreviewed.'Cyclization/dealkylation is alsoa usefulrerction.

E4

3-Chloro'1'hydroxytetrabutyldistonnoxone

Chloromethyllithium. Homologation of boracyclanes.t Chlo for one-carbonhomologation of boracyclan

Examples: C^H.

t-"

I,

(crH5)rN(CIt)4-COOH

socL

,\ ( -------r / + CICHIi I '

/ \

\

-P-

!,N(CH3)'

o

coH,.Jt'f-cH,+ y

(C2H5)2NCH2CHr'\J

c^H. fl " '\,A^ (cH3)2N(cH2)2{j{-c'Hs

82%

/

\

I OCH3

B-

T

OC

1

(l) is convertedto boraoctane2 in 82Vcvie ro synthesisof l2-memberedboracyclane dichloromethylmethyl ether (5, 201-2021 nones(3).

3:l

sax].

: (c2H5)2N(CH2)4CooH (*Ao

H. C. Brown,A. S. Phadke,andM. V. Rang

I CrHt 1 (1988). J. H. CooleyandE. J. Evain,Synthesis'

Chloroform. Reimer-Tiemann formylation of phenols.t Yields in this reaction can be inper creasedby use of solid, powderedNaoH and addition of water (2 equiv. phenol).

iodide (l ). ?. 2-Chloro-1-methylpyridinium (I mmunosuppressant r-F K-sffi (2). :emblescyclosporinA, a macrocyclicpollpl to transplantation,but FK-506v responses rhesisof (-)-FK-506 has beenachievedb The cyclizationto a carboxamidewas carr under high dilution in SlVo yield. The mo of a three-ketosequenceat Cr, Cr, and Ct 11Ouu

G*

fiLt?i5t?;, **.$* d;"" 1 (617o)

cHro

2 (141o\

rA.Thoer,G.Denis,M.Delmas,andA.Gaset,Syn'Comm',lE'2095(1988)'

o ClSn(Bu)1O-Sn(Bu)'OH (1)' The re3-Chloro-1-hydroxytetrabutyldistannoxane, dichloride.It existsas a dimer' dibutyltin of agentis obtainedby partialhydrolysis catalystfor tranesterian efficient Transesterification.r This distannoxaneis phenolsin refluxing or of alcohols ficationof methyl or ethyl esterswith a variety of functional variety wide a toluenein high yield. Sincethe conditionsare neutral, observed. not is groupsis toleratedand racemizationor isomerization Letterc,n,2383(1986)' l J' otera,T. Yano,A. Kawabata, andH' Nozaki,Tetrahedron

1//o

HO la

ocl 2 T K. Jones,S. G. Mills, R. A. Reamer.D S h i n k a iA, m . \ o c . , 1 1 1 ,1 1 5 7( 1 9 8 9 ) .

2-Chloro-1-methytpyridiniumiodide

E5

Chloromethyllithium. Homologation of boracyclanes.r chloromethyllithium is an efficient reagent for one-carbonhomologationof boracyclanes. Thus B-methoxyboracycloheptane

\\ r / o CuHr,A -N-c.H.

Y H - CH,I,N(CH'L'\J

'82% /+clcH"Li----+l

T

ocH3

I

\^

r

l"','=lT",'t 14% )

ocFI, 2

-

\

I )

Y

o

3

(l) is convertedto boraoctane2 in g2voyierd.This homorogation can be extended to synthesisof l2-memberedboracycranes. Reactionof the productswith o,edichloromethylmethyl ether (s, 20r-202) providesthe corresponding cycloatkanones(3). 'H. C. Brown,A. S. Phadke, andM. V. Rangaishenvi, Am. Soc., f10,6263 (1938).

\ :.Jr in this reactioncan be in| : . i . r : i r o fol f w a t e r ( 2 e q u i v .p e r

- ilc4

\:/

2-Chloro-1-methytpyridinium iodide (1), 7, 110;g, 95_96. Immunosuppressant ( - )-rr-s06 (2). This 23-memberedlactone-lactamresemblescyclosporinA, a macrocycric polypeptide,in that they both inhibit immune responses to transplantation,but FK-506seemsto be more active.The total syn_ thesisof (-)-FK-506 has been achievedby a processresearchgroup at Merck.r The cyclizationto a carboxamidewas carried out with Mukaiyama'i reagent(r) under high dilution in 8Lvoyield. The most unusuarfeature of 2 is the presence of a three-ketosequence at Cr, Cr, and C,6(hemiketal).

VoH

2 (r4%) ":-r . lt.2095(1988).

h b- -O-Sn(Bu),OH(1). The rehrr .::;hloride.It existsasa dimer. a:. :iicrent catalystfor tranesterioi .,..oholsor phenolsin refluxing Gu::.:..a widevarietyof functional iz.r:i,'nis not observed. t?:,-,:..1 nn Letters, 27,2383(1986).

T. K. Jones,S. G. Mills, R. A. Reamer,D Shinkai,Am. Soc.,111,1157(1989).

E6

N-Chlorosuccinimide

m-Chloroperbenzoicacid. Oxidative contruction of glycalsJ Reactionof 3,4-dihydro-2H-pyran(1) with benzeneselenenyl chloride and then with methanolprovidesthe adduct2, which is oxidizedby zr-chloroperbenzoic acid to the ring-contracted aldehyde3 (cf..,12, 120).Applicationofthis sequence to the tribenzyl-o-glucal (4) furnishesthe adduct l) c6H5secl 2) CH10H, N(CrH
8s%

,rrO'V* OBzl

OH I

CHrOH -------l-i.-r

I |

,r*

\oAo""

,

1

\olc"1oc",),

--f""'e-"| 3

2 BztO--".-O1

ccnfn.cr ,.t

CtC5HaCo3H

-r1-,SeCuH5 I

cs:NoHllfi

Bzlo-4o\,,oH

t

l

Bzlo"Y"SeCuH,

-ratt (

fton,("o"'

W oF (

OBzl

6

4

5

I o"J

D.sqo I

t o

H o o d "-Y">-\ziqn \ Ho/

/ tl toH o 7

5, which undergoessimilaroxidationto the aldehyde6, a convenientprecursorto antibioticshowdomycin(7). The aldehyde6 can alsobe prepared the C-nucleoside by oxidationof 4 with thallium(Ill) nitrate in acetonitrile. rA. Kaye,S. Neidle,andC. B. Reese,Tetrahedron (1988). Letters,29,2'7ll

(YtY"u''

w

\

o

alkyl-4-aminoquinotin"-r., Thus chlorination bv reactionwith N(CrH,), andtrappingwirh p CH:NOH

1yNgg 2) py.c.r|'c=Cxl 56*

Not 7

N-Chlorosuccinimide. Chlorination of aldoximes. NCS convertsaryl aldoximesto hydroxamicacid chlorideswithout significantchlorinationof the aryl group.This reactionhasbeen used for a novel synthesisof nitrile oxides.Thus reactionof salicylaldoxime(1) with pyridinegenerates a nitrile oxide, with NCS followedby dehydrochlorination which is trapped by styreneto give the isoxazoline2.' The N-O bond can be cleavedby catalytichydrogenationto 3, which is convertedinto the chalcone4 on eliminationof water. This product can be convertedby classicalmethodsto the flavanone5 and the flavone6. An analogousroute can be usedto svnthesize2-

,o',(

N-Chlorosuccinimide

cH:NoH ;1il:s^,

(1) with of -:.r-dihydro-ZH-pyran ol rrovides the adduct2, which lrtrntract€daldehyde3 (cf., 1ll, 'D-i.ucal(4) furnishes the adduct

CaHsCH =CH' _-j+ 54%

OH t

"u",

o-N ,

D-

n

'

/---f

\o,

\

rr* nz,n-"r Hi J

cH(ocH3), 3

l-srto.

^

I

\1">-'cHo I

-l I

\ / ,^-1

| I

ezto'

'oBzl

I

||

(\'oH,lcuH'

\^/tt

ll

I

o I

I te.s% |

8tt'n'

,#

'' -',,v'l =14 I

I

3

o"-

Y

Y

*o-(o> --4" C\' rr \J toH o

7 precursorto nJ: 6. a convenient ! "..:::rde 6 canalsobe PrePared

froY'o^'

l9. lTll (1988).

ror /tYo'-7Cou'

t . i l | - 5 1

w

\ryl l t l

O

O

5

6

alkyl-4-aminoquinolines.2 Thus chlorinationof o-nitrobenzaldoxime (7) followed by reactionwith N(CrH,).andtrappingwith phenylacetylene resultsin the isoxazole CH:NOH

1yxs5 2) ry, C6H!C=CH,

lli'-::1.e.

e,'

"^

.ttt'o

4

6

Ho/

E7

56%

Not CuH,

o-N E

to hydroxamicacid n .,.Jorimes n i:.'up. This reactionhasbeen (1.) B iir.tron of salicylaldoxime a nitrileoxide, pr::.1:regenerates tlr: J The N-O bond can be c.':.r.rtedinto the chalcone4 on ri(.: tr\ classicalmethodsto the r.l'ic.rn be usedto synthesize2-

-uo" jft,l*'ni

CoH,

Et

N-Chlorosuccinimide-Dimethylsulfide

8 in 56voyield. on prolongedcatalytichydrogenation8 can be convertedinto the isoquinoline9 in about 60% yield.The sequencecan be modifiedto providequinazolines. II. Thomsen andK. B. G. Torssell, (1988). ActaChem. Scand,R42,303 ' Idem,ibid.,842,309(1988).

N-Chlorosuccinimide-Dimethyl sulfide(Corey-Kim reagent). Selectiveoxidation of a primary hydroxyl group.t The first synthesisof the secoiridoid4 has been achievedfrom the tetraacetate(1) of secologanin,the biologicalprecursorof secoiridoids.Dihydroxylationof L with oso,, and potassium

Chlorotrimethylsilane. D iastereoselective|,4_addition o! a enone(1) hasbeenresolvedby kinetic rcr by cinchonidine. It undergoes highll.dir the presenceof ClSi(CH.).anOHMp'f ro 95Voyield-l This stereoselective Michael reaction from a cyclohexenone (l).,

ot l I (cH3)3siA/

ll

CHrMgBr, CuBr, s(cH,L,cls(cH!), e4qo

D

(G,}S

(R)- (-)-l

osoa,KCIO3, HO

gD - 9.5o

Dioxme, HrO 45qo

HOH2C

r(R=Ac)

c(cH,),

Oglu(OAc)o 7

rCHr)rSi ,no"lr.rcs.s1cHrl

o

-25 + 0' CH2CI2, J C6H5CH3,

M. Asaoka,K. Shima,andH. Takei,Tetral* V. Asaoka,K. Takenouchi, andH. nf<ei. Cf

i OH

oglu(oR)4 3 ,R = A c 4 ,R = H

chlorate2givesthe bicyclichemiacetal2. oxidation of 2 to the tetraacetate(3) of secogalioside (4) presentsthe problemthat the usualoxidants,PCCor thosederived from DMSO, oxidizethe lactol group of 2 more readilythan the primary hydroxyl group. However,the Corey-Kim reagentprovides3 as the only product,albeit in only moderateyield. Hydrolysisof 3 to the secoiridoid4 is effectedwith K,CO. in methanol(60% yield). ' L. F. Tietze,S. Henke,andC. Bdrtels,Tetrahedron, 44,7145(1988\. ' K. A. Hofmann,Ber.,45,3329(1972\.

Chlorotrimethylsitane-Seleniumdiorilc. ROH --->ft(1.r Chlorotrimethylsilar rlkyl chlorides,but this conversionproccc lctual reagentis believedto be selenium( r:olatedin 74Voyietd from the reaction of !

J G . L e ea n dK . K . K a n g , , /O. r g . , 5 3 . 3 6 !( t

Ctlorotrimethylsilane-Zinc chloride. Intramolecular tundem Michael rea Irnes suchas pentalenene(5) have been str :nrramolecular tandemMichaelreadion as :ncvclicsystem.Lithium amides, evenbully r dimethyl-r-butylsilyl triflate.Annelationt (]Si(CH.)i, zinc chloride, and N(C.H.).at t

Chlolotrimethvlsilane-Zincchloride

)n t ..rn be converted into the I -: :::Lrdifiedto Provide qulnH: : : (1988).

E9

Chlorotrimethylsilane. Diastereoselectivelr4-addition of cupratesto enones. 5-Trimethylcyclohexenone(1.)hasbeenresolvedby kineticresolutionvia the adductwith p-toluenethiol by cinchonidine.It undergoeshighly diastereoselective addition with cupratesin the presenceof ClSi(CH.)rand HMPT to furnishonly the trans-'|.,4-adducts in 8895Voyield.l This stereoselective Michael reactionprovidesa synthesisof ( - )-vetivone(3) (1).2 from a cvclohexenone

I : : . :i a n t ) .

the first synthesis of the ? .,. I r of secologanin,the bir': I .itth OsO. and Potassium C ' )Cl{,

\-

o

t'

CHrMgBr, CuBr, s(cH,\,clsi(cH3),

I

ll

I

r------

(cq)3siA/

e4%

,\ | t

| l

Br(cH,)r u,."r)t=ttc*!)z'znh'(tqa)

2) NaoCHl

(49Eo)

(cH3)3sitrL/.cHr

(R)- (-)-l oo-9.5o

)

I

OSi(CHr)3

tl

c(cH,), OAc).

rCHr)rSi c-- - r'ti,ctr,-:5+o' , )cH.

l

/\ )

I

oR).

i= ::

M. Asaoka, (1987). K. Shima, andH. Takei,Tetahedron Leuers,8,5669 M. Asaoka,K. Takenouchi, andH. Takei,Chem.Leuers,1225(1988). Chlorotrimethylsilane-Seleniumdioxide. ROH --->RCl.t Chlorotrimethylsilaneitself does not convert alcoholsinto rlkyl chlorides,but this conversionproceedsreadilyin the presenceof SeOr.The rctual reagentis believedto be selenium(IV)oxychloride,SeOCL,which can be :olated in74Vo yield from the reactionof SeO:with ClSi(CH.).. J. G. LeeandK. K. Kang,,/. Org.,53,3634 (1988).

(3) of D: : f, tc) the tetraacetate derived those or PCC \.J.rnts. e. r;i: r than the PrimarY hYdroxYl in !r -1 .. Ihe onlY Product, albeit in KrCO3 with effected is { :J n;

,g

- rj 11988).

Chlorotrimethylsilane-Zincchloride. Intramolecular tandem Michael rcaction,t Angular triquinane sesquitersnes suchas pentalenene(5) havebeensynthesized from the bis(enone)L by an .ltramoleculartandem Michael reaction as the key step for conversionto the ::rcvclicsystem.Lithium amides,evenbulky ones,are not usefulfor this step,nor . dimethyl-t-butylsilyl triflate. Annelation can be achievedby reactionof I with t'lSi(CH.)., zinc chloride,and N(C,H.). at 160"in either tolueneor CHrClr. Use

90

Chlorotris(triphenylphosphine)rhodiun

of either solventgivesriseto a mixtureof 2 and 3, but yieldsare higherin toluene. The ketones2 and 3 are convertedin three stepsin about707ooverallyield to the keto esters4 and then into pentalenene5.

Hydroboration of alkenes., Wilkin hydroborationwith catecholborane (CB). and stereochemistryof uncatalyzedhyd OH

CISi(CHe)r,ZnCb

r-IJ

\

ffi;;.

rtctit>''rnr' rob' O ,

J3". CH,

,-1

.)*CH" : ,A\24.

CH, CH,

cH'a-L-2

CH,

4

S

rM. Ihara,M. Katogi,and K. Fukumoto,"/.C.S.Perkin1,2963(1988)

Chlorotris(triphenylphosphine)rhodium(1). Decarbonylation of sugars.l Aldoses undergo decarbonylationwhen treated (NMP) at 130".Thus glucose with this organometallicin N-methylpyrrolidin-2-one (equation I). yield is convertedinto arabinitolin 88Vo

cHo H {o"

T"

HO

(r)

H H

CH"OH

-l-;

HO

I

Ton to"

I,NMP> 88%

I H +oH H

+ ClRh(Co) P(C.H),]'

*o"

cH2oH

cH2oH

A similar reactionwith ketosesis more complex.Thus fructoseis converted into furfuryl alcohol (797o yield).

cH2oH FO

no{n u-fou H-+-OH cH2oH

,.NMp, [oHc-7o;-cH,oH-l -.-4'o ie% \_/ ,t-cH,oH 'x,o \J ) L

OH

,,\

A

\./

\./

c)l ll-l

o" |

a otl

*

9.BBN 86% CB, cat. 84% OH

cr!oH

*,,

t t t ) L _| 9-BBN CB, cat.

83% 934o

I 9

cyclohexenol,the regioselectivityis rcw reactions,but the diastereoselectivitv is r

os

OSi+-BuMe,

ouysr^YzcH' CH, 9-BBN CB, cat.

--+ Bu 94% 80%

the exocycliccycloalkenes(equation It). diastereoselectivity, as does the catal!,zc cohols(equationIII). The catalyzedhydr resultsin the primary alcohol(>99.SVcar Cyclization of 1,6-enynef (cf. Ll. 9l: catalyzedby palladium or nickel complerc products.However, cyclizationcatalfzcd to methylene-2-cyclohexenes. Substitutio pressesthis cyclization,which probablv u bond of the terminal alkyne. Example: C2H5OOCv^\:cH

ar",oo"zV\cH,

ri(rr ot E

Chlorotris(triphenylphosphine)rhodium

[e hrgherin toluene' F orerallYieldto the

Hydroboration of alkenes.2 Wilkinson's catalyst is effective for catalysisof (CB), whichcandifferfrom the regioselectivity hydroborationwith catecholborane and stereochemistryof uncatalyzedhydroborationwith 9-BBN. In the caseof

,\ (Dl n

o

3 (35Vo)

\-/

OH

OH

OH

CH,

91

t

Ao"

ll-l

\,/

_

+ d , o H ^ *^

|

(,

OH

_

_

OH

l

u...,o",rr9o"

E3:2 1 8 I:

9-BBN 86% CB, cat. 84%

r

72:9

OH

cH2oH

}t,

ut,(, 9-BBN CB, cat.

lv\\

1:l 9 :I

83% 93%

cyclohexenol,the regioselectivityis reversedin the catalyzedand noncatalyzed reactions,but the diastereoselectivity is comparable.In the hydroborationswith OSi-t-BuMe,

orr I.rtionwhentreated Thusglucose l, .,r 130o.

.P, CuH5)3lz

u. lructose is converted

701--cHPn

: *_ll

CH,

CHt 947o 80%

osiR3

OSiR"

(rrr) Buv", ---.*r"\lo" 9-BBN CB. cat.

),

...crLoH

+

+ BuYoH : CH3 ll:89 96:4

the exocycliccycloalkenes(equationII), the catalyzedreactionshow high synallylic aldiastereoselectivity, as does the catalyzedreactionof 1,1-disubstituted cohols(equationIII). The catalyzedhydroborationof monosubstitutedl-alkenes resultsin the primary alcohol(>99.5Voat -40'). Cyclization of 1,6-enynef(cf. 13, 91,;14,299). Cyclizationof theseenynes ring catalyzedby palladiumor nickel complexesgenerallyleadsto five-membered products.However, cyclizationcatalyzedby Wilkinson'scatalystgenerallyleads ro methylene-2-cyclohexenes. Substitutionon either of the terminal groupssuppressesthis cyclization,which probablyinvolvesinsertionof Rh(I) in the C-H bondof the terminal alkyne. Example:

c,Hrooc'f\=c" CrHroocl-Aag,

^tlt''rfl*.-.r",:::11 -

13% ar"roo"zVcH"

y2

ChromicaciGChlorotrimethylsihne

satisfactoryyield. Unsymmetricaldisub,stn ketonesin about equal amounts.yields fr only fair. This oxidation is generallyusc suggests that the actualoxidantis a polp

rM. A. Andrewsand S. A. Klaeren,J.C.S.Chem'Comm',1266(1988)' 2 D. A. Evans,G. C. Fu, and A. H. Hoveyda,Am' Soc',110'6917(1988)' I R. Grigg, P. Stevenson,and T. Worakun, Tetrahedron, 44, 4967(1988)'

Chromic acid. in scetone (1, 142). Jones reagent can oxidatively rones reagent (cro!-H,) cleave sec-terr.L,2-glycolsin high yield.t An a-hydroxy ketone may be an intermediate (equation I). Note that an epoxide can also be cleaved to a keto acid.r

O*'?lj'"'"""

CI(},J, H3O'

CrOr, HrO'

50P _-_-,

_€

CH3(CHr)1CH:CHCH:

95%

97

-+

CH.(O

(I) AcO (CuHr)rC:CH,

cHrcooH as* ronoo"ia. J

;-r

(CuHr)rC:O

J. G. Lee andD. S. Ha, Tetrahedron Lcncr.

Chromium carbenereagents. [(D i methy Iami no)mert y k nelcllrc n iu, with diphenylacetylene at g0" in THF to fo (e). This ketene(a) reactswith iminesro f( stereoisomer.

Another example: CH,

(CO)rCr:C-

"CH:CHz I

o CH,

coocH3

6403(1988)' rR. de A. Epifanio,W. Camargo, Letters,29' andA. C. Pinto,Tetrahedron Chrornic acid-Chlorotrimethylsilane. alkenesare oxidized by o.-Chloro ketones. Both cis- and t/4t2s-disubstituted to a-chloro ketones in in CCL dissolved reagents two of these a combination

_N(CH.), -+ C.H,C:CC"I -H

Chrornium carbeneresgents

w. .:.6 (1988). , 1 1 1r1e 1 7( 1 9 8 8 ) . , +{ r$- (1988).

J ,:rr'sreagentcan oxidatively dr.'r', ketonemay be an interr' ^. cleavedto a keto acid.'

o

CrO3, CIS(CH3)3

cct4,25" ----------------+ E3%

CI

H. I l-'t../ D ,)

c

CrOJ, H3O* 5d -____------1 95%

CH3(CILCH:CHCH,

---+

l

o

^_- _l + CH,(CHJ.!HCCI-I, ti CH3(CHJ4CCHCH, l

o

l

l

c

(40Vo)

CH" I

a\v) t t *-o$9

93

satisfactoryyield. unsymmetricaldisubstituted arkenesafford both possiblea_chloro kelon-es in about equalamounts.yierds for oxidation of trisubstitutedalkenesare only fair. This oxidationis generailyuseress in the caseof l-arkenes.The report suggests that the actualoxidantis a polyoxochromium dichloride,Cl(CrOr)"Cl.r

(CoHr)rC:CH,

l CrlCoOH

rs* ronoo"ia. J

r

(40Vo)

(CcHs)zC:O

;-

J. G. LeeandD. S. Ha, Tetrahedron Letters,30, 193(19g9). Chromium carbenereagents. [(Dimethylaminolmethylenelchromium pentacarfunyl(l). r Thiscomplexreacts with diphenylacetyrene at g0" in THF to form rn sirr a comprexedenaminoketene (s)' This ketene(a) reactswith imines to form bicycricractams,usuallyas a singre stereoisomer.

jtF +c6H5c =cc.,,'

(co),Cr-.<;t"u /--,/.............cH'

4/

cH. l

l"c u : c H ,

o

\r,^r.-TCOOH

o'

f),:,r"c,*,l

'coocH,

zo-rs* ntr.r=cnn, J RI

29,6403(1988). v:.. : /t)n Leuers,

J'

o=r,'VR \ alkenesare oxidizedby rs:r:ulc'd rn ( Cl, to a-chloroketonesin

/

coH,Aflcun, (cH3)2N'

'H

Chromium carbenereagents

94

inadiated undergoes[2 + 2]cycloaddition Cyclobutanones.zThe carbenel when w i t h e l e c t r o n - r i c h a l k e n e s t o g i v e ' a f t e r d e c o m p l e x a t i o ncorresp.ond ( O ' ) ' c y c l oto b uthat tanonesin -60-85%oyield.The ,"glo- uni stereochemistryof the products that a keteneintermediateis involved' observedwith ethoxykeiene,which suggests is also efficient' An intramolecularversionof this cycloaddition cHcH3

l) ftv'cHrcN' 25"

-ocH3 ll (co),cr:c(.;.. . 8ucu,YA;-'

sH,9+ cH,ficH:

o*Tr^,

llllifo't"s*, fn _ ^.o(cH,),cH:cH, ** 1CO)rCr:C-:gg, "Lt?,

12+ 2lCycloadditions6 .t chromiumandtungsten underg widerangeof enolethers. Examples:

.,ocH3 (CO)rCr:C+ C[= -\-cH,

,a'rr*:a(]]",

Furanocoumarins.rTheangularfuranocoumarinsphondin(3)halbeensyn(Scheme vla the carbenelin20% overallyield thesizedin four stepsfrorn--r1Cd;'

*

ao

L. S. Hegedus andD. B. Miller.J : M. A. SierraandL. S. Hegedus, 'W. D. Wulff,J. S. McCallum. and ' K. L. FaronandW. D. Wulfi.ilxl

r). o "\ t /

-OCH"-

l

ftoY {,Y

rl HC=c(cHz)zcoocHr 2)TsoH

(CO)rCr:Cr

)1

ocH3

o-J/ ,

I Pdic 250' soe. r;uHrctc6H5, I

o

Scheme I

Chromium(Il) chloride. Intramolecular Nozaki ra poundto an aldehyde(1i2,137 rf the CrCl reagentis activatc conditions,the vinyl iodide witt 1 2 )a n dt h e 4 - e p i m ear s a l : 4 m

Chromium(ll) chloride

u:.: r rqoes[2 + 2lcYcloaddition in rrr,: O;), cYclobutanones that to |e :: .,iuctscorrespond is involved' [e:.: :ntermediate

95

[2+2lcycloadditions of alkynyl carbenes.a Alkynyl carbene complexesof chromiumand tungstenundergof2+2lcycloadditionat room temperaturewith a wide rangeof enol ethers. Examples:

h':::alent'

'

+

/ocH3 (Co),Cr 1____zCH, + CH.:C(OC,H.)"--' ---z -'- -z s,. l-l 739o

6H,9 S cH,ficH3

(CO)rCr:"t",

CrH5Of

o+'"'

oc2H5 CH:O

CH3O H

--+^

lF\

t

t

o2--l-o/

l

-a"+fw(co)j #a"-T]t" ,"Orr*:atr, . ro) e4% L e7% !t-\a", v't

Sa",

CH,

r-.: .rhondin (3) hasbeensYnI .: li r'i overallYield(Scheme

L. S. Hegedus andD. B. Miller,Jr.,J. Org.,54,t24t (1989). : M . A . S i e r r a n dL . S . H e g e d uAsm , . S o c . , 1 f 1 , 2 3 (3159 8 9 ) . W. D. Wulff,J. S. McCallum, andF.-A.Kunng,tDid.,ff0,7419(1988). 'K. L. FaronandW. D. Wulff,ibid.,110,8727 (1988). Chromium(Il) chloride. Intramolecular Nozaki reaction. The addition of a vinyl-chromium compoundto an aldehyde(L2, 137;14,96) is usefulfor macrocyclization, particularly rf the CrCl, reagentis activatedby a catalyticamount of Ni(acac)r.Under these conditions,the vinyl iodide with a or-formylgroup (1) cyclizesto (+)-brefeldin C t2) and the 4-epimeras a 1:4 mixturein60Voyield.l

ocH3

o)^-t

! .i

I Pdrc I c6H5oc6H5,25o'

o

*f3f;.1'n(--r SH, + 4-epi-2

ocH3 3

l:4

Chromium(II) chloride-Nickel(Il) chloride

syn-3r4-Butene-lr2-diols.2Reduction in situ of.an acroleindialkyl acetalwith adds crct, in THF provides a 1-alkoxy substitutedallylic chromium reagentthat diasterthe and rate reaction The 3,4-butene-1.,2-diols. to an aldehydeto afford eoselectivityare increasedby addition of ISi(cH),. Highest diastereoselectivity obtainsat -40o, but then the reactionis too slow for practicableuse'

aoH

J. "'('-e

HO.

lr

(

rl

I

Ho^V'........,) i Ho' OH

+ *t"o cHr: gllggloBzl),

tt"iJ'':!"#'b' cu':cn1An

OH

OBzl R = CeHs R = CoHdCHJz R = C(CHJ:

synlantt 8 8 :1 2 8 8 :1 2 33:67

98Vo 99vo 9rVo

(1988)' rS. L. Schreiber Am' Soc',110,5198 andH. V. Meyers, ' K.Takai,K.Hitta,andK.Utimoto,TetrahedronLetters,29,5263(1988)'

Chromium(Il) chloride-Nickel(ID chloride. as the first c-sucrose,t A key step in a synthesisof this saccharideinvolves a trace and by crcl, stepthe couplingof a vinyl iodidewith an aldehydemediated otNiCtr(14,97-98).Thuscouplingofthevinyliodidelwiththealdehyde2' inversion derivedfrom o-arabinose,providesan allylicalcohol,whichon Mitsunobu C-sucrose to converted providesthe threo alcohol3 as the major product.This is

BzlO...

BzlO

CH" t ' CH;-f-O ' t I CH" + OV,\../,CHO : ^, OBzl

4 ,c o * ! l (4) in 30Vooverall yield by stereoselecivec phorsulfonicacid (CSA), which cleavesthc r cyclization to a triol, which is a protected d dation of 3 and its erythro isomer can provi< of 4. I U. C. DyerandY.

Kishi,L Org.,53,33g3 (lH

Cobalt(fi) chloride. RCOSi(C&)r - RCSSi(CIIr)r.t Acvbi lanesby reacrionwith bis(trimethylsilyl)sui6d vield). The reaction is also applicableto a thioaldehydes, which can be trappedby dicr

o ll

cfh.6rlo

-lg!!g. cH3(cHr)5isitc4),

C6H5CHO--+

|I - $ l*j ll r LC6H5CHJ

Cleavage of epoxideswith ClSi(CHrlr' high selectivityto provide primary chloridesr I r; crct2,Nic4 I2)

invasion

n

r.u' l) clc6H4co3H 2) CSA 3) H2, Pd(OH)2 -

BzlO...

BzlO

-o o _l_ I CH, CH,

10% overall

/-\

cqo

+ CtSi(CrL[

rr ot

ffi-

Cobelt(Il) chloride

rt ir'rndialkyl acetalwith )rr.rumreagentthat adds icr rale and the diasterghestdiastereoselectivitY use' ac'.rcable OH I

1:CH:.-R I OBzl s)nlantl 8 8 :1 2 8 8 :1 2 33:67

!\ t :lnl (1988).

the fint chunde involves as a trace and :Jr.'tcd bY CrClt

2' f,i. f *iif, the aldehYde inversion hr.hrrnMitsunobu C-sucrOSe ru. r. collv€rted to

"1"-oH

!

"'*i6lY'\"" OH 4, o,o+ 21.6"

(4) in 30Vooverall yield by stereoselective epoxidationand treatmentwith camphorsulfonicacid (CSA), which cleavesthe acetonideand the epoxidegroupwith cyclizationto a triol, which is a protectedderivativeof 4. Stereoselective epoxidation of 3 and its erythro isomercan provide the four C2,and Cr, stereoisomers of 4. U. C. DyerandY. Kishi,l. Or9.,53,3383 (1988). Cobalt(il) chloride. RCOSi(CHil - RCSSi(CIIr)r.t Acylsilanesare convertedinto thioacylsilanesby reactionwith bis(trimethylsilyl)sulfidecatalyzedby CoClr.6HzO(60-90Vo vield). The reaction is also applicableto aldehydes,which are convertedinto thioaldehydes, which can be trappedby dienes.

cocl2.6Hp ? fi cH3(cHJ5dSi(CH')' CH3(CHr)5CS(C4)3 %

cH,"\--./ cH.

1-\ \ /

t"o

)-s

Y

CoHt

()Bzl

Cleavage of epoxideswith ClSi(CH)*' CoCl catalyzesthis cleavagewith righ selectivityto provide primary chlorideswhen possible. cocl2' ,O.

l-\ (- lf-

1

-('l{, I

I clc6H4CqH l; CSA lr Hu' Pd(OH)z , 30% overall

5cH3cN

+ ClSi(CH.). ----=-+ 8l%

ffi-@=

9E

Collidinep.toluenesulfonete

vic-chloro esters.! cobalt(Il) mediates regioselectivecleavageof oxiranes with acyl chloridesto give vicinal chloro estersat 0o'

o

r P. A. JacobiandJ. L Kravitz, Tetrahc

tl

cocr2 ft 3 ?cc6H5 crH5cHCHrCl c,H,iHcH,otc,H,* coH,cocl #L

o A+

C,Hi

4: I

o

f

l

f

f

ctcHrcHoicH:CHCHT . cHrCH:CHicl ;;* EVo

A

c6H5ocHi.

l_ ^^-cHpc6H5

a-"-a"' I

O + C6H,COCt""'

(

/....o",rru^, o

J' Org'' 54' 19(1989)' I A. Ricci,A. Degl'Innocenti, andG' Reginato, A. Capperucci, ' J. IqbalandM. A. Kahn,Chem.Leuers,ll57(1988)' Letters'29'4985(1988)' t f. tqUat,M. A. Khan,andR. R. Srivastava, Tetrahedron Collidine p.toluenesulfonate(1, CPTS)' to phenols. This sulfonatecaneffectan acid-catalyzed cyclization of enynones (equationI). Thusthe enynone2 canbe cyclized phenols to enynones of cyclization from to the phenol 3 by catalysiswith 1. Note that a differentphenol (4) obtains cyclizationof the enol acetateof 2' acid-catalyzed

crH,r

0)

I

-l

tr",t.-

-_F\'''ilds"'' c,Hi |."1}o" fo

ch, 2

I

Lcl

):/

" '1".

lcH.co,c=cn,

I

lr'oH

Y

"^l-*

Copper,Cu(0)*, 9,122. A highly active form of copper dr CuI.P(C2H.),with lithium naphthala vinyl halidesto organocopperreaten self-coupling (Ullmannreactions).Ho benzyliodides at 25ogiveshomocor compoundscross-couple with acid ct highyield.' This Cu* specieson reactionwirh q reagent.This undergoesan intrarno regioselectivity of reactionof Cu. rr

o D

./Br

l

l

I THR-7r CrHrGr

cd

3

e

561 ,tYl

Br e ttt

C,H'\-

"'" "'| I "; ,ro'.",4o" \J

J

For cyclizationof thesesubstrar catechol.

2

i-rlvent,but the substrate2 cyclizesto Llivent.This reactioncan alsoefieo q

G W. EbertandR. D. Rieke,,I. Org .5 I -C. Wu and R. D. Rieke, Tetrahedr $ehmeyer, T.-C.Wu, andG. W. Ebcn. ,

C"H..

('ctt/,V

( !oo. 'crH,

CH, 4

Crpper(Il) acetate-Anthrscene. Knoevenagel condensation; rei ,. ;,OAc): and KOH, di-r-butylmaloru r':r paraformaldehyde to give dir-bu

Copper(Il) rcetate-Anthrscene

of oxiranes cleavage Dr.e,ective rr

o ll

rP. A. JacobiandJ. L Kravitz,Tetrahedron (1988). Letters,29,6873

t l + C2H5CHCH2CI ICH.OCC6HT 4:1

ot l ' CICH.CHOCCH:CHCH: -l

cH,oc6H5 zt"'zcl \-,"

see4-l-butylFor cyclizationof thesesubstratesto methylenecyclopentenones catechol.

occ6H5

o

l

y)

r 'occ6H5 il

o 1 9( 1 9 8 9 ) ' G 3 : i r n a t o .I O r g , 5 4 ' t\\ (1988)' *t.:' r Leuers.29,4985

C o p p e rC , u ( 0 ) * ,9 , 1 2 2 . A highly activeform of copper slurry (Cu*) can be preparedby reductionof CuI.P(CrH.)3with lithium naphthalenide.This Cu(0) convertsaryl, alkynyl, and vinyl halidesto organocopperreagentsat sufrcientlylow temperaturesto prevent (Ullmannreactions).However,reactionwith primaryalkyl, allyl, and self-coupling benzyliodidesat 25'gives homocoupledproductsin high yield. The arylcopper with acid chloridesor with alkyl halidesin moderateto compoundscross-couple highyield.l This Cu* specieson reactionwith epoxyalkylhalidesforms an epoxyalkylcopper reagent.This undergoesan intramolecularcyclizationvia epoxy cleavage.The regioselectivity of reactionof Cu* with the substrateI can be controlledby the

o

XILOH- X" LJ

(-/"* 5L.: rrte can effect an acid-catalyzed 2 can be cYclized I i: u. the enYnone (4) obtains from t . .::dcrent Phenol

I THR -78" c6H5cH3 o

cHr..J)

cil

I

c'H5\-

- ",nl-----.---.",-$o" '1"" Y cs' I 3

t \-,

-.Br

t

\-,J (entu)

(exo)

1:6 1:0

56% 45%

CH><,H a(, c

u

r

l

l

3 (3) regardlessof the :olvent,but the substrate2 cyclizesto l-methylcyclohexanol rings.2 s)lvent.This reactioncan also effectcyclizationto three-membered (1988). G. W. EbertandR. D. Rieke,./. Org.,53,4482 Letters,29,6753(1988);R. D. Rieke,R. M. T.-C.Wu and R. D. Rieke,Tetrahedron (1989). Wehmeyer, T.-C.Wu, andG. W. Ebert,Tetrahedron,45,443

c.ti.

Copper(Il) acetate-Anthracene. Knoevenagel condensation; methylidenemalonates. In the presence of Cu(OAc)zand KOH, di+-butyl malonateundergoesa Knoevenagelcondensation This method is rrth paraformaldehyde to give di-t-butyl methylidenemalonate.'

100

Copper(I)bromidc-Dimethylsulfide

not useful for the lower analogsbecauseof anionic polymerizationof the products. A more general route to methylidenemalonatesinvolves a Knoevenagelcondenin the presenceof anthracene, sationof a dialkyl malonatewith paraformaldehyde The [4+2]cycloadduct(1), reaction. which traps the product by a Diels-Alder reactionto give the metha retro-Diels-Alder when heaied at200-250',undergoes yield.' (2) in 30-80% ylidenemalonate

#'"l?ffI',H}" I I

(ROOC)rCH,+ (CHP)" -l'\r)\-/\2 ll

cuHrVcl+cHrZncr-( Cu(I) Nior)

6?* 65e

Allylation catalyzedby NiCl, comp actionwith equallyhigh selectivitl.. ' K. SekiyaandE. Nakamtra, Tetahcdrn

)

4o-8M

2ffi-2',"> cH":c(cooR)z 30-80%

Copper(I) chloride. Alkyl carbamates. In the prescnc rn DMF at 25" with alcohols,even rcrti 96Voyield.

)

I I P.Ballesteros, B. W. Roberts,andJ' Wong,J' Org'' 4t' 3603(1983)' (1988)' andP.Dumont'ibid'' 53,4859 2J.-L.De Keyser, c. J. c. De cock,J. H. Poupaert, Copper(Il) . o x i d a t ibromide. onofallylstannanes.|OxidationofthesecompoundswithCuBr,in allylicalcohols,ethers, the presenceofwater, alcohols,or sodiumacetateprovides oracetates'AllylicaminescanbeobtainedbyoxidationinTHFinthepresence of an amine. CH.

r

SnBr.

l

%*,"1Nu

cH,r\-Bu

I

cH,\lBu 73% Nu=OQHs Nu=NH(CHr)zCeH:73%

+

CHt

Bu

83:17 1 4 :8 6

CH'

I T. Takeda,T. Inoue,andT' Fujiwara,Chem'Lefers'985(1988)' bromide-Dimethyl sulfide, CuBr'S(CH')z' Copper(I) 'inz;-l,uylotron with a variety of R.rz,i or RZnCl.t cinnamyl chloride reacts Vo) at20" to (5 mole of organozincreagentsin the p,es"nce of this Cu(I) reagent is comparableto that of give the Sp2'-productsof allyiation' The regioselectivity RCu-BF, at -70'.

ROH + C64CH(R)NCO(R=H,CH!)

\t. E. DugganandJ. S. Imagire..S-rnrAc

Copper(Il) nitrate-Montmorillonirc (Cli Nitration and ofidation.t Clar,_su .. :helf-stablefor months.Like clayfen. ;.eavethioacetalsor selenoacetals to tlx -: effectsaromatizationof 1,4-dihydrop :i aceticanhydride,it can effectnitratioa ..,.:'a-preference, which can be enhance ? LaszloandA. Corn€lis, Aldrichimica Aa

(1per(I) thiocyanate,CuSCN. .4renethiocyanation.t Thiocyanano r,.. resultsin both arenethiocyanates an ]l< reactioncan be effectedwith CuSCI rr.moarenesreact with this supponedn r .re the correspondingthiocyanatesin

Copper(I) thiocysnate

lr rr.cnzation of the Products' ilre. ,r KnoevenagelcondenD:he presenceof anthracene' (1)' - Thc [.1+2lcYcloadduct meththe give to der reaction

101

9H, c6H5

=

cl + cHrZnct -Cu(I) Ni(ID

+ cuHrA.zcH2cH3

au"r&cH,

67Vo 65Va

92:8 8:92

Allylation catalyzedby NiCl, complexedwith a phosphineinvolvesan S*2 reactionwith equallyhigh selectivity. E

Letters,29, 5155(1988). Tetrahedron K. SekiyaandE. Nakam,tra,

r:'

R :'o-25o"'

CH":C(COOR)z

rl-t04

Copper(I)chloride. react Alkyl carbamates. In the presenceof CuCl (1 equiv.) alkyl isocyanates in 45rn DMF at 25" with alcohols,even tertiary ones,to form alkyl carbamates 96Voyield.

, CuCl,DMF

.n,,i (1983). (1988)' P Dumont,ibid',5t,4859

ROH + C6H5CH(R)NCO # (R=H,CHr)

?

C6H5CH(R)NHiOR

l31 (1989). \1. E. Duggan andJ. S. Imagire.Synthesis, in he:c comPoundswith CuBrt ethers' alcohols' prrt'rr,Jesallylic rtirlr,rnin THF in the Presence

N,r

,

-

CHr-;\r,Bt

I

CH, : r b

. -.< r1988).

flr a variety rrr. chloride reacts with at20' to Vo) nt I r reagent (5 mole that of to le;irrtrr-is comParable

Copper(Il) nitrate-Montmorillonite(Claycop),12, 231. Cu(NO3),,unlikeclayfen(n, nI), N itration and oxidation.t Clay-supported .. shelf-stable for months.Like clayfen,it is a convenientsourceof NO2* and can to the carbonylcompoundat 25" in high yield. :,eavethioacetalsor selenoacetals in 80-92Voyield. In the presence It effectsaromatizationof 1,4-dihydropyridines .f aceticanhydride,it can effectnitrationevenof halobenzenes at 25"with marked which can be enhancedby use of lower temperatures. :.rrc-preference, Aldrichimica Acta,2l,97 (1988). P LaszloandA. Corn€lis,

Copper(I)thiocyanate,CuSCN. Arene thiocyanation,t Thiocyanationof areneswith metal thiocyanatesusuand the more stableareneisothiocyanates, r.l1 resultsin both arenethiocyanates lhe reactioncan be effectedwith CuSCNsupportedon charcoal.Thus iodo- and -romoarenesreact with this supportedreagent(excess)in t-butylbenzene at 150o '". sive the correspondingthiocyanatesin70-807o yield.

lfiz

Cyanotrimethylsilane

'J. H. Clark, C. W. Jones,C. V. A. Duke, and J. M. Miller' l.C.S. Chem.Comm.,81

(le8e).

uf,ruCN

I

cyano(methylthio)methyltrimethylsilane, (cH.).sicHSCH, (1). The reagent is CH3SCH,CN,with trimethylsilyl availableby reactionof methylthioacetonitrile, yield). triflate and N(CrHs).in ether at 0-5" (80-85% a-cyano vinyl sulfides.r The lithium anion of L undergoesa Petersonreaction with aldehydesor ketonesto give thesecyanosubstitutedsulfidesasElZ mixtures in 60-95Voyield.

, *

ton')c-e CH,/

-$' c1"'14!1,-SCH3+ (cH,),SioLi 6t% CHr'

EIZ=5:1

CH" ',Fe(CO.)" ; ( _ tcg6s ll I I I @_9A

Y.", I

'o"(

Asymmelri c hydrocyanadn reactionof aliphaticor aromatr ticallyactivereagent(l) derivedt poxytitanium(IV).The actualch

rD. I. HanandD. Y. Oh,Syn'Comm.'lE' 2111(1988). CuHra_CuH, 2-Cyanopyridiniumchlorochromate(l), L3' 87. s-Chloro ketones. This chlorochromate(5-11 equiv.) convertsalkenesto c-chloroketonesin 40-95Voyield. The workup is facilitatedby use of Celite as adsorbent.In rare casesallylicoxidationcompeteswith oxychlorination,and epoxides are occasionallyformed as by-products.'

C.Hr- ,O-lOfr > ( l

cH,1J.. ..-oH +rio/c c6H5. c6Hj I, ao + g3o

o c l PrCH:CHn lW

i l l

PrC-CHPr

formed from 1 and TiCl,(O_i-pr) rexcess)and an equivalentof2 ar optically active cyanohydrins.

,/f--/cl -------| { I s'tc. \Ao (exo)

R(AI)CHO + CiS

IA. F. Guerrero,H. Kim, andM. F. Schlecht, (1988)' Letters,29,6707 Tetrahedron cyanotrimethylsilane,(cH3)3sicN.This silaneis presentin solutionin part as the isocyanideisomer, (CH3)3SiNC.'And indeed it is more useful than NaCN for cyanationof the iron complex12to provide2 and 3, intermediatesin a projected synthesisof tridachione.

Asymmenic Strecker amino sl iatalyzedby ZnCl, to opticallyacrr 3-o-galactopyranosylamine as the ( r-aminonitriles,dependingon the iiereomers,whereasCHCI, favon ,

Cyanotrimethylsilane rltr

M \ l r l l c r .J C - S 'C h e m 'C o m m ' ' 8 7

cH3o\^<

Y"' .Fe(co")" (cHl)asNc

i l l ll | \'^cHl

('\ I

is l:r( llSCH, (l)' The reagent trimethYlsilYl with r ll :('H:CN.

6o-9s%

I

cHro

\ t < . J,

?",,.r("o.).

Fe(COr)r CrH
reaction a Peterson o: I undergoes mixtures asEIZ ut.rrturedsulfides

.zCH,

"cN

52%

cH3o\//\<' ll l-cH' V"'cocH,cH, 3

+ (cH3)3sioLi


t .

Asymmetric hydrocyanation of aldehydes.s This reaction can be effectedby and an opreactionof aliphaticor aromaticaldehydeswith cyanotrimethylsilane and dichlorodiisoproacid, ticallyactivereagent(1) derivedfrom (2R,3R)-tartaric 'H NMR to be poxytitanium(IV).The actualchiral reagentmay be 2, shownby

Jt'.

CuHsa-CoH, I

to .. equiv.)convertsalkenes as Celite of use bY l t . ' r.rcilitated epoxand .i 3 : ! ' ' rth oxvchlorination,

cuHr- cuH,

cuH,-,o=foH 25",'co",- ro)2Kocd
cuHr

c.rt,

1,co+ 83"

o c l

L r-r-lrm

)

formed from L and TiClr(O-i-Pr)r.An aldehydewhen treated with (CH.).SiCN t excess)and an equivalentof 2 and 4-.4,molecularsievesat 65' is convertedinto opticallyactivecyanohydrins.

+ cNSi(cH,), R(tu)cHo k"?Xi(73-96Vo ee)

6707 (1988) trr:' . :', )tI Leuers, 29,

in Part as the llc : - nres€otin solution than NaCN for C.l .: r\ more useful in a Projected 2 t :J J. intermediates

AsymmetricStreckeramino acid synthesis.a Addition of cyanotrimethylsilane ;atalyzedby zncl, to opticallyactivealdiminesformed from 2,3,4,6-tetrapivaloylas the chiral auxiliarycan result in either (R)- or (S)3-o-galactopyranosylamine r-aminonitriles,dependingon the solvent.THF or isopropanolfavors (R)-diawhereasCHCI. favorsthe (S)-diastereomers. stereomers,

llf4

CYanotrinetbYlsilane

NHC.R -cN

,/

Cyanuric chloride. Lactonization of e-hydroxy acids. 1 oxazepine2 in 557oyield by cyanuricchl The combinationof cyanuricchloride an

H J

I

fc!( HOOC?O Ho *cH, * \-J "cH! cuHr"

G/s)=7-13:1 (S/R)= 3-9: I

(cHJ2cHoH cHcl3

R'Li to the p-quinolsl'-formed by addition of 2'4-Dialkyl'l-naphthols's The can undergo (S'7n)' with cyanotnmethylsilane monoadductof 1,4-naphthoquinone of 2 with HI provide the diol 2' Reduction to RzLi a secondaddition of n'r-ilt l) (cH)lSicN'

P(C6H)!

I

+ N(CrHr), +Py 2,6-Lutidinc

t'lr

5A
for macrocycliclactonization(10, ll{-l caseof l. In fact, the presentlactonizat

2) R'Li, -78" 3) AgF 65-95qo

R. T. BrownandM. J. Ford,,!yn.Comm.

o OH

B'

o{x" HoAc'<42 .
i' 3

1 pt= 6r = CH. R'=Bu, *= CHr Rr=CrHs,R' = Bu

897o

oH 4 1A^

4l7o 544a

91a

HI under as expected'but reductionwith in THF givesa 1,4-dialkylnaphthalene to a 2'4-dialkyl' -Fl" in a dienone-phenolrearrangement more acidicconditions'""uf'* 75-95% yield' in obtained is :- Rt' a singleproduct 1-naphthol,3 or 4' Wnen dependingon naphthols'3 or 4' can be formed' But when Rr I R2,t*o Oiff"'"nt are separableby and R2' In any case'the naphthols the migratoryaptitudesof Rr chromatograPhY'

(198'7\' J'C'S Dalton'2013 rR. P. Alexander, T' D' James'andG' R' Stephenson' Perkin1' 2069(1988)' l'C'S' ' R. P. Alexand.',C' fufotf"V'andG' R' Stephenson' Bull' Chem' andK' Narasaka' I H. Minamika*u,S' Huyu"/u*l'r v"t"o"' N' Iwasawa'

(re88)' Leuers'2e'43e7 retrahedron andD Schanz'i:i:k' . if ii111;1t*'.t:#.Tt1:"rre' (1988)' ibid"29' 4827 5 J. A. Dodgeand A' R' CnulU"ttin'

Cyclic sulfatesof 1,2-diols. Unlike epoxides,thesefive-member tion from organicchemists.But the rece alkenes(14,237-239),which is now wi& accessto optically active natural l.2dio rncludinga convenientmethodfor synth reactionof a 1,2-diolwith thionyl chlon qhich is then oxidizedin the sameflect as shownin equationLI

HO'..

/

OH

/ \r.,

r\

-

socl'. cH{I.

R = n_CcHu

Cyclicsulfatescan evenbe prepared6 .rcetonide,silyloxy) by reactionwith tlt .ridation of the isolated sulfiteswrth I rucleophile,the resultingsulfateestersca r THF catalyzedby H2SOa.The use of :hemoselectivity.2

Cyclic sulfatesof l,2-diols

P:r -----l

aoPiv,., "f

D

I=-\k*f1. H

Cyanuric chloride. Lactonization ofe-hydrory acids, The e-hydroxyacid 1 is convertedinto the oxazepine2 in 55voyield by cyanuricchlorideand pyridineas basein 55vo yield. The combinationof cyanuricchloride and triethylaminehas been recommended

7

Hooc4ro

R.S)=7-13:1 SR )= 3 - 9 : 1 rrcJ hr additionof R'Li to the h\ .r..rne(5,722),canundergo io. I Reductionof 2 with HI

HO

NCH"

\-/ c.Hr"

"cH,

RlLi _ 78"

1,,

/

\ CtH'""Y'

\zo I 3.NCH3

2 (2S,3R) 27Vo 557o <5Vo

R. T. BrownandM. J. Ford,Syn.Comm.,18 1801(1988).

770 94o

. :u: reductionwith HI under to a 2,4-dialkYlrr'rrr.rngement r r. ,'htainedin75-95Voyield. on .Jr hc formed,dePending bY are seParable thc n.rphthols Dahon,2013(1987). It: L : I'trkin/,2069(1988). Bull. Chem. re -::rJK. Narasaka, ai'

q

for macrocycliclactonization(10, 114-115),but this method is lessusefulin the caseof 1..In fact, the presentlactonizationis remarkablysensitiveto the base.

-.---->

R.

o\--^. (cNcD! cH,cN ,

CH,

I + N(CrHr), +Py 2,6-Lutidine

D \

105

Cyclic sulfatesof l,2-diols. Unlike epoxides,thesefive-memberedheterocyclics havereceivedscantattention from organicchemists.But the recentcatalyticasymmetricdihydroxylationof alkenes(14,237-239),which is now widely applicable(this volume),and the ready accessto optically active natural 1,2-diolshas led to study of thesecompounds, rncludinga convenientmethodfor synthesis.They are now generallyavailableby reactionof a 1,2-diolwith thionyl chloride to form a cyclic sulfite of a 1,2-diol, *'hich is then oxidizedin the sameflask by the SharplesscatalyticRuo, system, asshownin equationLr

Hq

o\zo

/oH

( D R R = n-CuH,,

_--:--

SOClr, CHrClr

P{ry

o"' oI '. / R

cyclic sulfatescan evenbe preparedfrom diolscontainingacid-sensitive groups acetonide,silyloxy) by reactionwith thionyl chloride and N(crHr). followed by .rxidationof the isolated sulfiteswith Ruoo (catalytic).After reactionswith a nucleophile, the resultingsulfateesterscanbe hydrolyzedby water(0.5-1.0equiv.) rn THF catalyzedby HrSOo.The use of a minimal amount of water is crucialfor .'hemoselectivity.2

(Cy.b

. Cyclicsufiatesof l,2'diols

1()5

soc[ N(c2H5]2

9H

R,^,-R' I OH

cH2cr2)

Ndoa Rucl3,

?lZo

u-

)

R'1,i-R' L6

-'$

' Y. GaoandK. B. Sharpless, Am. Soc..llO. r B. M. Kim andK. B. Sharpless, Tetrahedro p-Cyclodextrin(CD).

a*'^f*'#'*'a*' LiNr.

o

N,

N.

osos-

oH

Reactionswith nUcleophiles. Many of these reactionshave been carried out with cyclicsulfate1, availablein 90-93Voyield from diisopropyl( + )-tartrate.This sulfate is reduced at pH 4-5 by sodium cyanoborohydridein THF to diisopropyl (R)-malatein 55Vo(equationII).

Asymmetric synthesis of ,ql(c|'J]P.] thioacetates, Ar(CH,)"SCH,COOR.comp tically activea,o.-dichlorosulfoxides in {-5 highestoptical yield is obtainedin rhe orx Photochemicsl processesof CD coq reactionsconductedin solution and in CI example,photo-Friesrearrangement of phc of o- and p-phenolicketonesvia a radrca encapsulated esterresultsin exclusiverean

o tl

OH :

l) N8BH'CN

,OyCoO-i-Pr ii ii;or'-', j_prooc&coo-,-Pr 0D OrS. I b-"'coo-,-n

occ6Hr

.,4.

o)ll

I

\/

The reaction of l with sodium azideat 0o provides p-azidomalates,which are useful precursorsto cr-amino-p-hydroxyacids (equation III). OH N!Nt,0-25'

oDr#

Rooc fcooR N3

Sincec,p-unsaturatedestersundergocatalyticdihydroxylationin high yield, a reactionof 2 with a number of nucleophileshas been investigated(equationIV). In all reportedcases,the nucleophilereactsexclusivelyat the c-position.In contrast, reaction of epoxideswith thesenucleophilesshowsno suchregioselectivity.l gH

02

(tv)

,so.

.9

\

'COOCH3

n-C"lti

t

g,r11r,-r1\'c4ooc Nu

| ---*

cH3oH

p-cD

tion I). Similarselectivephoto-Claisen rearr allyl ethersto provide only one of the tno I

K. RamaRaoandP.B. Saltur,J.C.S.Chem( : V. Ramamurthy andD. F. Eaton,Acc.Chen.

(Cyclooctadiene) ( 1r6-cyclooctatriene)ntlcr Silylation of alkenes. The complexpn allylsilanes as the major product. 'CH'

"'ta"r",

ot

9H'

""'&cH'

+ HSi(c'Q

CHr(CHr)rCH:CHr+ HSi(CrHJ,

;

Cft

2 Nu = NaBH.(f)%); C.HTCONH.(83%)',NH.SCN(90%);Bu.NF(637o)

\'. Horl,T. Mitsudo,andY. Watanabe, Buil.A

(Cyclooctadiene)(l,Gcyclooctatriene)rutheniurn 107 ' Y . G a o a n d K . B . S h a r p l e sAs m , . \ o c . , 1 1 0 , 7 5 3 8( 1 9 8 8 ) . :B. M. Kim and K. B. Sharpless, Tetrahedron Letters,N,655(1989).

o

o7bo. ^,.-\L/R' \, o/ l t -t

p-Cyclodextrin(CD).

o

Hro* n-gr%

\,.rt

dddl

osor-

N, r

o,A/R' I oH

sctlLrllshavebeencarriedout 6llHrpropyl( + )-tartrate.This rr.lnde in THF to diisoProPYl

tl

Asymmetric synthesisof Ar(CH),5*CHClz.t Oxidation (NaOCl) of areneresultsin opAr(CHr)"SCHTCOOR,complexedwith B-cycloodextrin rhioacetates, in 4-54% ee in70-83% chemicalyield. The tically activecr,o-dichlorosulfoxides highestoptical yield is obtainedin the oxidationof C.H.SCH,COOBu. Photochemical processesof CD complexes.z Differences in photochemical reactionsconductedin solution and in CD complexeshave been reviewed.For of phenylestersin solventsresultsin a mixture example,photo-Friesrearrangement of o- and p-phenolicketonesvia a radical reaction.Rearrangementof the same to the ortfto-position(equaesterresultsin exclusiverearrangement encapsulated

o

OH

-,\

D C v

tl

-coo-i-Pr

(r)ll \/

' \, cooR I \.

in high Yield,a drhrdroxylation (equationIV)' len rnvestigated !r\el\ at the c-Position.In consh!\\ ! no suchregioselectivity.t

. -cH"ooc

i" H.SC\(90%);Bu.NF(637o)

,\

. l l l

I

Y

1 . 6 I: 9 9 :I

cH3oH O-CD

obtainswith lrr-alkoxyphenyl rearrangement rionI). Similarselectivephoto-Claisen rllyl ethersto provideonly one of the two possibleorffto-isomers. (1989). K. RamaRaoandP. B. Saltur,l.C.S. Chem.Comm.,342 (1988). V. Ramamurthy andD. F. Eaton,Acc.Chem.Res.,21,300 Ru(COD)COT). t Cyclooctadiene)(1,6-cyclooctatriene)ruthenium, promotes silylationof alkenesto provide The complex of alkenes. Silylation product. as the major rllylsilanes

HrC

I

coc6H5

coc6H5

which are de- B-azidomalates, r t r o nI I I ) . H

OH

?cc6H5

::,o. cr,'t:ct'+

CH,(CH,)rCH:CH,

+ HSi(CrHr[

HSi(c,H,), # ;;*

"",'Lsi(c2H5)3

CH3(CHr2&CH2Si(C2H5)3 ElZ -- 65:35

\' Horl, T. Mitsudo, and Y. Watanabe,Bull. Chem.Soc.Japan,6l,301l (1988)

1$

Cyclopropyldiphenylsulfonium tetrofuoroborate

Cyclopropane. in synthesishas beenreviewed(293references).' The useof cyclopropanes I H. N. C. Wong,M.-Y. Hon, C.-W.Tse,Y.-C.Yip, J. Tanko,andT. Hudlicky,Chem R e v . , t 9 , 1 6(51 9 8 9 ) . Cyclopropyldiphenylsulfoniumtetraflqoroborate, f

\

?

-

|[}s1c.ur;,

BFo(l), 4,213-214.

Cationic cyclization with vinylcyclopropyl silyl etherc.t These ethers can serveas terminatorsin a cationiccyclizationinvolvingacetals.Thus reactionofthe providesa vinylcyclopropyl keto acetal2 with l andthenwith a baseand ClSi(CH3)3 ring (4) in silyl ether 3, which undergoesfacile cyclizationto an eight-membered the presenceof trimethylsilyltriflate. / O ll

cHi

OCH.' |

tcn,l,A o"".

l) l, KoH,DMso Y 2)LiN(c2H5)2,cls(cH3h-

-

9Si(CH3)3

1,4-Diazabicyclo[2.2.2loctane ( DAI Reactio n of ethyI 2,3-butadicru propionaldehyde in ether at 23" rn r yield, formed by replacementof thc effectedwith butyllithium, but rhen of 1. CH':6-g"COOC,H5

cHrcHfirc)

I + DABCO + BuLi

c.

OCHj I

I

A ocH, H2c4 (cHz),

CH.:C:

3 (cL),siorr, .,."-- | | Pv. CILCL

+ -

u- M ethyI ene- p -hydroxy _y _aI Lorl pared by an aldol-typereactionof a mediatedby DABCO or l-azabicvcl trve. Example: 4 (9:1)

OCHTOCH3 CH, This strategy can also be used to obtain fused-ring systems such as 5.

'

cH,

l

cHo

l

+ cHCocH,

OTMS CHt

(CHrhSiOTf ---:--+' 9l%

'B. M. Trostand D. C. Lee, Am. Soc.,l10, 6556(1988).

S.Tsuboi, S.Takatsuka, andM. Uraka.( : S. E. Drewes, T. Manickum, andG. H I

l.E-Diazabicycto[5.4.0]-7-undecene (D O-and S-Akylation. This bar f: and S-alkylationof p-toluenesulfinic ac

re\ rc\\ed (293references)'t . l-:rrt). and T. HudlickY, Chem'

1,4-Diazabicyclol2.2.2loetane(DAB CO). Reaction of ethyl2,3-butadienoatewith aldehydes.t This ester (1) reactswith propionaldehydein ether at 23"in the presenceof DABCO to provide2 in 42Vo can also be yield, formed by replacementof the g-proton of 1. This condensation effectedwith butyllithium, but then 2 is accompaniedby 3, formed via a dianion

ll-11.1. jlr.l ethen.t These ethers can Thus reactionof the ing .rcetals. 1l r frovidesavinYlcYcloProPYl ring (4) in I r: crsht-membered

of 1. cHr:g-g"cooc2H5

cH3cH2cHo t

I + DABCO + BuLi

.,1 osi(cHJ3

\l/

l

Hcr'\(cHz),

c2H5cHoH

c2H5cHoH

9cH, l

:CCooCrH, CHr: g-g"ooc2H5 + CTHTCHCH:C

ocH,

OH

3

"" I8:dii'il'

2 427o

3

58Vo

69o

a-Methylene-$-hydroxy-y-alkoxyketones.2 These compounds can be prepared by an aldol-typereactionof alkyl vinyl ketoneswith o-alkoxy aldehydes The reactionis anti-selecmediatedby DABCO or 1-azabicyclo[2.2.2loctan-3-ol. tive. Example: 4 ( 9 :l ) QCHTOCH3 I-nrs rvst€fllSsuCh as 5'

"> a-a \"i\tocu,

5 ( 7 :1 ) F..

CH,

cH,AcHo * 8""o"",H9-

CH3OCHTQ

9H'

"",#(t"' o H o = 7l:29) (antilsYn

(1988)' andM. Utaka,Chem.Letters,2003 S.Tsuboi,S. Takatsuka, 'S. E. Drewes, andG. H. P.Roos,Syn.Comm.'fE' 1065(1988). T. Manickum, (DBU, 1). I,E-Diazabicyclo[5.4.01-7-undecene $-and S-Akylation. This basefacilitatesesterificationof carboxylicacids' acids.2 and S-alkylationof p-toluenesulfinic 10,!)

110

l-N,N-Dibenzyl-c-amino rldehydes

p-CH3C5H4SO2H + RX + DBU

#

p-CEC6H4SO2R

I D. Mal, Syn.Comm.,f6, 331(1986). 2G. Biswas (S),308(1988). andD. Mal,l. Chem.Research (N3),Ti(O-iPr), (1), 13,2I7. Preparation.rThereDiazidodiisopropoxytitanium, agentcan also be preparedin situfrom Ti(O-r-Pr)oand 2 equiv. of (CHr)rSiN,in refluxingbenzene. a-Amino acids.2 Treatment of 2,3-epoxyalcoholswith 1 affords 3-azido1',2diols, which can be convertedto amino acidsby RuOooxidationto c-azido carboxylic acidsfollowed by catalytichydrogenation.

o cJr,&oH

OH I

-L-'.tt'yA,,oH

RuCl3

-g{9Lc#,

cooH ,

N3

N3 ( 1 0 0 :l )

R'M, t4\ L-l (R= C4) cHr'

2 CHTMgI cH3Li cH3Tict3 (CHr)rCuLi

n% 9t% t2% W*

""':"(ott

t2* ocH3 /oc6Hs .TiO. 25* C[:C_'os(cH3)3

^uJila,.* cJ,ycooH NH2.HCl

' R. Choukroun (1980). l.C.S.Dahon,1800 andD. Gervais, 2M. Caron,P.R. Carlier,andK. B. Sharpless, (1988). J. Org.,53,5185 Preparation.' Di(benzene)chromium(0). Dehydrogenation catalysts.2 Reduction of di(benzene)chromiumwith potasto 1,4-cyclohexadiene sium sandin DME generatesa speciesthat dehydrogenates probenzene.The catalyst prepared from benzene(1,3-cyclohexadiene)iron(0) and disproportionationto cyclohexeneand benzene. motesdehydrogenation

(CuFIu)rCr. O

p-Amino alcohols.t Alkyllirhium i p-aminoalcohols(2 and 3), with the latu CH3TiCl3,SnCl, can favor the chelatro

25o K'DME ' O

I M. T. Reetz,M. W. Drewes, andA. Sctri

Dibenzyl azodicarboxylate(1). 2-Amino glycosides.t Furanoid or ; this azodicarboxylate undergoa [4+21c1 (3) in 70-80% yield. The adductson trct inversionat Cr to give hydrazines(l). r hydrogenolysis and deprotection. R3Sio-\./o)

,, ^"

\--t/a

&sio-{\\

R3SiO'

RlSiO

t

'E. O. Fischer, Inorg.Syn.,6,132(1960). ' G. Fochi,Organometallics, 7, 2255(1988). N_NHCOOBd

r,-N,N-Dibenzyl-cr-aminoaldehydes,(1). Preparation: RCHCOOH

I

NH2

"*"

COOBzI 4

l) LiAlH.

RCHCOOBzI NBzl,

2)(coclL/DMso, ) RCHCHO

I

NBzlt L-l

Actually, the adductsare cleavedbv includingvariouscarbohydratealcohols. polysaccharides.

Dibenzyl ezodicrrboxylete

* :-CH.CoHrSOzR

p-Amino alcohols.t Alkyllithium and Grignardreagentsadd to 1 to provide B-aminoalcohols(2 and 3), with the latter predominating.Addition of Lewisacids, product2' CH3TiCl.,SnCL, can favor the chelation-controlled

t\.

BzlN,

. 1 3 .l l 7 . P r e P a r a t i o n . ' T hr e ). ;nJ I equiv. of (CH,):SiN,in

t -cr

c6H5.,, cooH I N3

I u". Parc teu" ntr I Y

c6H5

_

cooH

I

NH2'HCl !"* , ' s - l 5 1 8 5( 1 9 8 8 ) .

,OH

L-1(R=CHr)g

*

cHr">1R'

BzlzNa__-OH 'R' ""r"

2

3

87% 9l7o 82Vo 80Vo

5:95 9:91 94:6 25:75

cu':6(oli-ocH3 827o

5:95

CH'MgI CH3Li CH3TiCl3 (CHr)rCuLi

oh,.l. nith l, affords3-azido1,2Ru(), oxidationto c-azido car-

H +5

111

/oc6H5 CH':C-- 'os(cH3)3'TiClo2l7o

95:5

lM. T. Reetz,M. W. Drewes, Angew.Chem.Int. Ed '26' 1141(1987). andA. Schmitz, Dibenzyl azodicarboxylate(1). 2-Amino glycosides.tFuranoidor pyranoidglycals(2) when irradiatedwith undergoa [4+2]cycloadditionto form a dihydrooxadiazine this azodicarboxylate (3) in 70-80Voyield. The adductson treatmentwith methanol(TsOH) open with inversionat C, to give hydrazines(4), which furnish 2-aminoglycosides(5) on and deprotection. hydrogenolysis

with Potas' hrr**nzene)chromium to dr\rrenates1,4-cYclohexadiene I i .:-lclohexadiene)iron(0)proo :rclohexeneand benzene.

, z-'\

:-+

R3sio1.,o),.^",R3sio 1o'rzo\--oBzl _ruL \--ll ;;

88%

.H*_,(' i

R3SiO

R3Sio

cooBzl

2 ,

ll

3

\-/ n

R3sio1,,-1..'ocH,

,-1 'N-NHCooB'l

\

R'sio

/

llli;$.-*n'-soA(o;."ocHr Bq.

L---{

." |.--'NH'

Ho

COOBzI 4

' ^ H

I

:

5

-'.rlr/DMSO

) ) K CHCHO

I

NBzlt L-l

Actually, the adductsare cleavedby various primary or secondaryalcohols, includingvariouscarbohydratealcohols,and thus can be used to obtain aminopolysaccharides.

Itz

1.3-Dibromo-3,5-dimethylhydantoin

lithium-halogenexchangeprovidesl with electrophiles.

I W. Chen,E. K. Stephenson, andM. p r

o phosphorofluoridate, Dibenzyt (Bzlo),$a Or, b.p.-150./0.2mm.

o ll (Bzto),i-oH+ ll,4, I \ttA.

rro- *,,'iF,,, r eoqo

CH,

o -';:L ' [,u,,",,[], Phosphorylation.t Dibenzyl phosphorochloridate is widely used for phosphorylationof alcohols,but is more difficultto preparethan the fluoridate.phenol is very readily phosphorylatedby 1 and csF in cHrcN, and indeed a phenolic hydroxylgroup is selectivelyattackedevenin the presenceof a primary hydroxyl group. Primary and anomericalcoholsare preferentiallyphosphorylatedin the presenceof a secondaryhydroxylgroup.Alcoholsthat are insolublein acetonitrile can be phosphorylatedby L and DBU in placeof CsF. 'Y. Watanabe, N. Hyodo,andS. Ozaki,Tetrahedron (l9gg). Letters,29,5763 1.,3-Dibromo-3,5-dimethylhydantoin (l), 12, 158-159.Supplier:Aldrich. Regioselectivebromination t This reagent.is superiorto NBS for bromination of pyrrole to provide 2-bromopyrrole.After conversionto the N-boc derivative,

'""1"':l-#'--?" ?.1 AIBN.

(cH.).cocolo

Boc

I t) nuli 70% | 2) cts(cH3b THF, -?8 + 0o J

l-\

\^sr1cH,y, I Boc

3,5-Di-/-butyl-I.,2-benzoquinonc,3. l RTCHNHT-->RzC:O,t Alrhorl 1969,it has not been used widet;-.A from both acyclicand cyclicamines. 2-amino-4,6-di-r-butylphenol, can bc chemicalor dichromateoxidationrn 5 I R. F. X. Ktein,L. M. Bargas, andV Hr

Dibutylboryl trifl uoromethanesrfiof Boron enolates of thioglycobtaof the low acidity of the c-protons.Hr a boron enolateon treatmentwith Ho enolateundergoesaldol reactionsrrd ity.' $C"H. _ LbGe | CH3CHO+ CHTCOOCH,j%5

G

't

' Y. SuganoandS. Naruto, Chem.plurm.

Di-t-butyl dicarbonate(r-Boc,O). NHCbo --> NHBoc. This inrercq hydrogenationcatalyzedby pd_C in O can also be effectedby reactionwith 1 ethylaminein the presenceof excessr-l ' M. Sakaitani, K. Hori, andy. Ohfunc.Ia

2,6-Di-r-butyl-4-methylphenol. Conjugate addition to a,p-ur.rrcl are too hinderedto form esterenolat6. I conJugate additionof organolithiumrea .l-methoxyphenols, which are easill.clc observationthat BHT estersare redls

2,6.Di-r-butyl-4-methylphenol

113

lithium-halogenexchangeprovidesN-boc-2-lithiopyrrole for subsequentreaction with electrophiles. rW. Chen,E. K. Stephenson, andM. P.Cava,Org.Syn.,submitted (1989). 3r5-Di-t-butyl-1r2-benzoquinone, 3, 78-79. pr(--Q.r Although this conversionwas originallyreportedin RTCHNHT-.-> 1969,it has not been usedwidely. A recentoverviewreports yields of 83-937o from both acyclicand cyclicamines.A further advantageis that the by-product, 2-amino-4,6-di-t-butylphenol, can be convertedto the benzoquinoneby electrochemicalor dichromateoxidationin 55-65Voyield.

5 i , ' t J . 2m m .

' ' ) l

rR. F. X. Klein,L. M. Bargas, (1988). andV. Horak,J. Org.,53,5994

fu:: rr widely used for phosarc :hanthe fluoridate.Phenol 1l ( \. and indeeda phenolic rr..cnceof a primaryhydroxyl in the Rn::rll\ phosphorylated ha: ,rc' insolublein acetonitrile l:F

Dibutylboryl trifl uoromethanesulfonate(1). Boron enolatesof thioglycolates. Estersdo not form boron enolatesbecause of the low acidityof the a-protons.However,methyl phenylthioacetate (2) forms a boron enolateon treatmentwith Hunig's baseand dibutylboryltriflate, and this enolateundergoesaldol reactionswith aldehydeswith high syn-diastereoselectivity.'

fcuH' r

,,l:.'l;;.

CH3CHO+ CHTCOOCH,s5-+ 'oo

,

lcoH,

CH''Y -J- -cooan' OH

^1. 96:4

s t . . 2 9 . 5 7 6(31 9 8 8 ) . 5" :upplier:Aldrich. tra-:r,)rto NBSfor bromination rr.:,:r to the N-bocderivative,

-ll

t-----:\

\\

\/-t.

t) nul-i '0,+I zy | cts1cH35 -?8+0' JrHF,

si(cH3)3 Boc

| OH

I Y. Sugano andS. Naruto,Chem.Pharm.Bull.,%,4619(1988). Di-r-butyldicarbonate(t-Boc,O). NHCho --->NHBoc. This interconversioncan be effected in high yield by hydrogenationcatalyzedby Pd-C in CH.OH in the presenceof excesst-BocrO.It can also be effectedby reactionwith (CrH.).SiHcatalyzedby Pd(OAc), and triethylaminein the presenceof excesst-BocrOin C'H.OH. rM. Sakaitani, (1988). K. Hori,andY. Ohfune,Tetahedron Letters,29,2983

Boc

I

lCuH' a"'a4coocH3

2,6-Di-r-butyl-4-methylphenol. Conjugate addition to ar$-unsaturated esten. Fsters (BHT) of this phenol are too hinderedto form esterenolates,'but ct,B-unsaturated BHT estersdo undergo conjugateadditionof organolithiumreagents,2 asdo esters(BHA) of 2,6-di-r-butyl4-methoxyphenols, which are easilycleavedby CAN oxidation (13, 94-95). The observationthat BHT estersare reducedby sodium in liquid NH. to the corre-

tt4

2,2-Dibutyl-2-stanna-1,3-dithicne

cH"

t -

+ CH:CCOOBHT -

cHrI

Na.NH3 ._

90%

45%

t

LiF

aldehydereactsmore readily than an er reversedin the caseof an aromatic d& betweena straight-chainaldehydeand a I

I

BucHo*n-c,n,,c{]**

tt'-O

a-

'jf"n,o"

Cor(CO)r 5tEo

CH,

c,oH7cHo.*"{]

c=cH

, cJ

6 (cis/trans = R R .1 ' \

4

BUCHO + (CH,)TCCHO -+

BoO \

CH,

7

spondingalcohol providesa synthesisof angularlyfused triquinanepentalenene (7). Thus conjugateadditionof L to 2 followedby in situ methylationfurnishes3, which is reductivelycleavedto the alcohol4. This is convertedby known reactions to the enyne5, which undergoescyclizationwhen heatedwith Cor(CO)" (t2, 1,64) to a mixtureof two triquinanes6, in qhich the productwith the desiredconfiguration at Cr and Copredominates. Remainingstepsto the pentalene7 areknownreactions. rR. Hiner,T. Laube,andD. Seebach, Am. Soc.,f07,5396(1985). 2N. E. Schore andE. G. Rowley,ibid.,ll0, 5224(1988).

rurr6t I 2,2-Dibttyl-2-stanna-1,3-dithiane, '5J

' M. Wieber and M. Schmidt,I. Organoma.C : T. Sato,E. Yoshida, T. Kobayashi,J. Orcn. r ( 1988). 'M. Schmeisser, P. Sartori,and B. Lippsrnckr

3,4-Di-r-butylthiophene l,l-dioxide (l). Preparation:

o\ (c\\c'/

lo Tftt:". tcH,;{ fc(cn"i"

(1).

The reagentis prepared'in about 50Voyield by reactionof propane-l,3-dithiol with Bu,SnCl,and N(CrH,)3. Reaction with RCHO and acetals.2 In the presenceof dibutyltin bis(trifluoromethanesulfonate), 2,3this reagentconvertsaldehydesor their dialkyl acetals or ethyleneacetalsinto 2-alkyl-1,3-dithianes (70-85Voyield).However,the reagent differentiates betweenaldehydesand acetalsasshownin the examples.An aliphatic

1r2-Di-r.butylbenzenes.r This reagenrr phenylvinyl sulfoxide,an acetyleneequivalc acid to give o-di-r-butylbenzene in Tl% *l

3,4-Di-t-butylthiophenel'l.dioxide

Na./t',1H3 --------------)

\-

45qo

115

aldehydereactsmore readily than an ethyleneacetal,whereasthe selectivityis reversedin the caseof an aromatic aldehyde.The reagentcan also distinguish aldehyde. betweena straight-chainaldehydeand a branched-chain

-( IOBHT

BuCHO+ , "r",r"{]

g

/SI

BuCrH

s-/

/S

+

)

n-C,H,rC{{

s 93:7

\+

".",{] - ",rr,iD c,oH?cHo.

. ".r,"i]

6 (cisltrans = 8 8 :1 2 )

3:97

BuCHO + (CHr)TCCHO+

,sl

BuCrH

s-/

)

+

/s

(CHICC\H

s 80:20

I M. WieberandM. Schmidt, Chem.,1,336(1964). J. Organomet. r T. Sato,E. Yoshida, Leuers,29'3971 J. Otera,andH. Nozaki,Tetrahedron T. Kobayashi, ( l e88). 'M. Schmeisser, (1970). andB. Lippsmeier,Ber.,103,868 P.Sartori, fu.rJ triquinanepentalenene i;::, methylationfurnishes3, r.1\.rtcd by knownreactions a:c.j rrith Co:(CO)'(n,rc4) e::h thedesiredconfiguration lt;.c1c7 areknownreactions. lr

-,.5).

1,l-dioxide (1). 3,4-Di-t-butylthiophene Preparation:

o\

rict4.z^tcH,l,c[Pc(cH,), lo r (CH")^C1 \c(cH")" -M ' i \ s3% \r/ \r/

1vr.ox 2)crcrH'colH '

(CH3LC\

/C(CH3)3

lt \ \s/ r:.trLrnof propane-1,3-dithiol rc..rce of dibutYltinbis(trilehrJcsor theirdialkYlacetals i ,,rc.J). However,the reagent An aliPhatic r r1 :hc examples.

o2 I This reagentundergoesa Diels-Alder reactionwith 1r2-Di-r-butylbenzenes.r phenylvinyl sulfoxide,an acetyleneequivalent(8, 399),with lossof benzenesulfenic in77Vo yield. acid to give o-di-t-butylbenzene

116

Dibuivltin oxide

I S. J. Danishefsky, R.

o-t'tfo""',1t"')'tfi I + cuHrSocH:a",

Hungate, andG. Sdrs

+ sor+ c6H5soH (cH^)"cN

Dicarbonyl(cyclopentadienyl) t (dinrcthybr Cp(CO),FeCH,S(CH3),BR-(t), air-stab

2 (77Vo)

Diels-Alder reactionsof I with a varietyof alkynesprovidesa route to various substitutedo-di-r-butylbenzenes. ,,
D !)

t(CO)rFeCpl,I

(cH:)rc-a'1"'Bu ll (cH)^cA?

I

Cyclopropanation.t This stable me$ panationof alkenesin generallyhigh yield of 1,1-disubstituted double bonds.

(CH3)3C\f\aCooCH3 I + CHTOOCC=CCOOCH,-'--------+ ll I (cH3)3c,,,J9coocH3

coocH3

'J. Nakayama, (1988). S. Yamaoka, T. Nakanishi, andM. Hoshino, Am. \oc.,110,6598 Dibutyltin oxide. Intramolecular Williamson reaction,r The final stepsin a total synthesisof octosylacid A (1) from riboseinvolve a cyclizationof 2 to 3 via a 2' ,3'-stannylene (a).

tt"t)a:a". Ctlrt

o

I M. N. Mattson,E. J. O'Connor, p. and Hclqr

cH3oocY\_H Bzro cH3ooc

co",

" e6%r CH,

Bu2snolH

"\*\

4

CsF, DMF, 60' 17% qdrll

HO

Di-p-carbonylhexacarbonyldicobelt,Cor(O A Ikyne-C oz(CO), complercs,(RHRI 163;12,163-165;14, tL7) can be prepared pentenonesin moderateyield. CoBrr+ Zn + CO

*t,

-

[-c.r-rcor - * Lvw2\Lr-rrt

RoocY\_H

"\r\

".4#l

ROOC 3, R=CH:,R'=Bzl I, R=R'=H

Cobalt-based annelation of silyl cnot c psuedoguaianolides involvesthe reaction of

Di-p-crrbonylhexrcrrbonyldicobalt ' S . J . D a n i s h e f s k y ,R . H u n g a t e , a n d G . S c h u l t e ,A m . 9 o c . , 1 1 0 , 7 4 3 4 ( 1 9 8 8 ) . \-t\

| + SOr+ C6H5SOH

/''\v

Dicarbonyl(cyclopentadienyl)[(dimethylsulfonium)methyl]irontetrafluoroborate' (1), air-stable,stableto storage(13, 98-99). Cp(CO)rFeCH,S1CH.;,BF.l) Nr 2) CICH2SCH3 3) CH3I

a routeto various [\:lc: provides

gh [(CO)rFeCp],

t

3u

,',c\.,YcoocH3 I ,,c'^'6........Z^-coocH3 (1988)' r: : . .'{m.Soc.,110,6598

i.:.'. .teps in a total synthesisof )n ,'r 2 to 3 via a 2',3'-stannYlene

Cyclopropanation.t This stable methylene transfer reagenteffectscyclopropanationof alkenesin generallyhigh yield. It can effectselectivecyclopropanation double bonds. of 1.1-disubstituted

coocH3

,

d\coocH3

\A, 8",""'

+ Cp(CO),FeS(CH3)r'BF;

'il>':'"';'Jl:< I M. N. Mattson,E. J. O'Connor,andP.Helquist,Org. Syn.,submitted (1989).

sas;l | |

,\

,-=1

''\^ ,1

)

Bu/

|

|"^"'il'"'', I

-o I n l

-rul

71%

*'"'

Di-p-carbonylhexacarbonyldicobalt'Coz(CO)r. Thesecomplexes(11, 162Alkyne-Co{C O) 6complexes,(RHR)Co2(CO).'' 163;12, 163-165;14, 1I7) can be preparedin situ and usedfor synthesisof cyclopentenonesin moderateyield.

CoBrr+ Zn+ COB ) :L-H st\

( -\ oll lt

..IIi% fCor
HC=CC6H'3'Co1CO)J

".4*4d",",, Cobalt-basedannelation of silyl enol ethen (10, 129). A potential route to cationcomplex psuedoguaianolides involvesthe reactionof the ethoxy-substituted

118

Di-p-carbonylhexacarbonyldicobalt-Methyl iodide

I with a silyl enol ether such as 2 followed by demetallation. A mixture of four productsis obtained, all with completeero-selectivityat C, adjacentto the carbonyl group. Two of the productsare epimericat C7,and two are epimericat Cl,.

"t*J"

,--\

CoH,

c'f,d 'Br

(E) or (4

CH,

CHt

CH

lll-Co,(Co)o1) CH2CI2

C BF,'

I *cHoc2H5

2) CAN --:.+' 15%

I

..CH, \-,ocrHt

CH,

,.CH,

oCr4

t

'M. Miura,K. Okuro, A. Hattori.aod!

,"\" \" 3 ( 4 :1 )

4 ( 6 :l )

Silorymethylation.3 Glycosyl acetatesundergo C-siloxymethylationon reaction with a hydrosilaneand CO catalyzedby Cor(CO)'. Only the anomeric acetoxygroup undergoesthis reaction,which takesplacefrom the side opposite to that of the acetoxygroup at C3.The reactivereagentis probablya silylcobalt carbonyl,R,SiCo(CO)..

HS(CH,L, CO Coz(COL

-

75-78%

Dichlorobis(cyclopentadienyl)ft O-Aryl glycoside -- C-orlt gtf with phenolor 2-naphthotat -7ff in in O-glycosidation.As the tempera rangesto a C-glycoside.CprHCl5A effectivefor this rearrangement. Ur, O- and C-glycosides(equation I). t in the presenceof the hafnium actrv tion II).

AcO AcO

cHrosi(cE)3

OAc ' A. Devasagayaraj and M. Periasamy,Tetrahedron Letters,30,595(1989). ' A. M. Montafia,K. M. Nicholas,and M. A. Khan,J. Org.,53,5193(1988). I N. Chatani,T. Ikeda,T. Sano,N. Sonoda,H. Kurosawa,Y. Kawasaki,and S. Murai, ibid., s 3 , 3 3 8 7( 1 9 8 8 ) .

cHroJro.(l)

\

F /

r,, +c64oHj

T-l

crLo ocH3

clu Di-;.r.-carbonylhexacarbonyldicobalt-Methyl iodide. Carbonylation of vinyl halides. These two reagentsreact to form tetracarbonylmethylcobalt,CH.Co(COI. In the presenceof hydroxideion, this organometallicand carbon monoxideconvert vinyl bromidesor chloridesinto the correspondingcarboxylicacids.

Dichlorobis(cyclopentadienyl)hafniurn-Silver P€rchlorote

119

H

-H [-n H I \_-_./ cH3co(co)a )| >< tcotco)rcoon I cuHr,^B. l"u"r' I (E)or(z) CH, L I

iiarr.rn. A mixture of four C :djacentto the carbonYl o :re epimericat Ct'.

,on "o, "
(E) ..CH,

\.-.oczlt

I M. Miura,K. Okuro,A. Hattori,andM. Nomura, PerkinI,73 (1989). "I.C.S.

\" 4 ( 6 :1 )

on reC-.riorvmethYlation a n omeric t h e O n l y tCor.. Iacefrom the side oPPosite ln: r. probablYa silYlcobalt

2\, \

perchlorate (1). Dichlorobis(cyclopentadienyl)hafnium-Silver O-Aryl glycoside -, C-aryl glycoside.t The reaction of a glycosyl fluoride with phenolor 2-naphtholat - 78oin CHzCLin the presenceof a Lewisacid results in O-glycosidation.As the temperatureincreasesto 0' the O-glycosidationrearrangesto a C-glycoside.CpzHfClz-AgClOo(or CprZrClr-AgClOr)is particularly Use of other Lewis acidspermitsisolationof both effectivefor this rearrangement. (equation I). In the caseof glycosidationwith B-naphthol O- and C-glycosides presence activator, only the C-glycosideis isolated(equaof the hafnium in the tion II).

,-O

-.---s-LcHrosi(cH3)3

cHro-Lo-'.

F

.{cO

o) 30 a.r5(1989). s - 15 1 9 3( 1 9 8 8 ) . K:u.r:aki,andS. Murai,ibid.'

\

I

n cHro ocH,

+cuH,oH

BFr.qqHJl -7815' )

CH,o1.o...OCuu, \ / !e::. reactto form tetracarhrJrtrxideion, this organox ..r chloridesinto the cor-

H

cH3o ocH3 (45Vo;

c/F= 5: 1)

cH3o

Dichlorobis(cyclopentadienyl)zirconium

D..r

o

.4..,+ CH3(CHrLCI|O

(,

ctq cH3o ocH3 (B/o= 9:t) rT. Matsumoto, (1988) Letters,29,6935 M. Katsuki,andK. Suzuki,Tetrahedron Dichlorobis(cyclopentadienyl)titanium-Magnesium Reductionof Cp,TiCL with 1 equiv. of Mg in THF resultsin a greensubstance (1), which may be a THF adductof CprTi. reducesepoxidesto alkenesin 85-95Voyield, Deoxygenation. This substance generallywith retentionof configuration,particularlyin reductionof trans-epoxides.This reductionproceedsmore readily than that of carbonylor estergroups, but c,p-enalsare coupledreductivelyby I at 25" to diallylicethers.

Glycosidation 2 The ready acccssr 183) and pyridinium poly(hydrogenfru suitableactivatorsfor use of these firx Although the metallocenesof Zr and AgClOa(1 equiv.), they efiectrapid gl- 20' to 0" with a varietyof alcoholsin 1 canbe controlledto someextentby thc I by the solvent.A further advantageof alcoholscan undergothis glycosidation

' R. Schobert, Angew.Chem.Int. Ed.,n,855 (1988).

'T. Nakano,H. Shirai,H. y. kl Tamagawa. ' K. Suzuki,H. Maeta,T. Matsumoto. andt 3571(1988).

Dichforobis(cyclopentadienyl)zirconium,CprZrCl, (l). of 2r6-Dialkylphenols, Thesephenolsare obtainedby a cross-aromatization with aldehydescatalyzedby this zirconiumcomplex.CprTiCl,and cyclohexanones CpzHfClzare also effectivecatalysts.'

Dichlorobis(diphenylphosphinometbcl Thioetherc; thioacetals.t In the pa thiolsreactwith alkyl iodidesto form rhi condensewith 1,l-dihalidesto form thb t

RCH2 + 2 RCHO

HS(CH)3SH+ 2CrI\t -

I' r5o't

,.Ji'ill"*

R=C:Hs 697o R=CH(CH:Lr6vo

o

tl

| \

cH3(cH2)4

(cH2)4cH3

S-..--s

+ 2CH,(CH,),CHO

|

40qo

cH3

CH,

P. C. Bulman Page,S. S. Klair, M. p. Brorr and S. Mulley, TetrahedronLetters,E). {,{l7

Dichlorobis(diphenylphosphinomethrne)plotinum(II)

o

Ft..

,\ I \-/

o ),,vcr<"H2)3cH3 l + C H , ( C H r ) r C H o ' h - " , 1| \-/

C'H.O cH3(cH2)2

cH3o ocH3 (0/s= 9:1) n : ; " 8 . 6 9 3 5( 1 9 8 8 ) .

re.ultsin a greensubstance r,' rikenesin85-95VoYield, rn reductionof trans-eqox' oi ;arbonyl or estergroups, l a l l rl r ce t h e r s .

I of I :r .r cross-aromatization nr:nr complex.CPrTiCl and

(cH2)4cH3

Glycosidation.z The readyaccessof glycosylfluorides,thanksto DAST (12, 183)and pyridinium poly(hydrogenfluoride) (12, 419), has led to a searchfor suitabfeactivatorsfor use of thesefluoridesin glycosidation(12, a66;13,302). Although the metallocenesof Zr and Hf are inert as such, in the presenceof AgClOa(1 equiv.), they effectrapid glycosidationof a typical glycosylfluoride at -20o to 0" with a varietyof alcoholsin generallyhigh yields.The stereoselectivity canbe controlledto someextentby the metaland the sugarand to a greaterextent by the solvent.A further advantageof this systemis that even highly hindered alcoholscan undergothis glycosidation. T. Nakano, H. Shirai,H. Tamagawa, Y. Ishii,andM. Ogawa, J. Or9.,53,5181(1988). :K. Suzuki,H. Maeta,T. Matsumoto, Letters,29,3567, andG. Tsuchihashi, Tetrahedron 3s71(1988). Ptcb(dppm), 1. Dichlorobis(diphenylphosphinomethane)platinum(Il), Thioethers;thioacetals.t In the presenceof this catalystand a weak base, thiolsreactwith alkyl iodidesto form thioethers.Under the sameconditionsthiols condensewith 1,l-dihalidesto form thioacetals. I, Na2CO3

HS(CHr)3SH + 2CrHrl

#

C2H'S(CH)3SC2H5

I CH'L. ?o% l, N-a;co3 J

t

OH

S-...-S

l

,...-.,V,cH2)4cH3

I

\4cH3

P. C. Bulman Page,S. S. Klair, M. P. Brown, M. M. Harding,C. S. Smith,S. J. Maginn, Letters,29,4477(1988). and S. Mulley, Tetrahedron

tn

Dichloro{1,1l[bis(diphenytphosphine)]fenocene]pelledium

ClNi(dppp) (1). Dichloro(1,&bisdiphenylphosPhinoproPane)nickel' Coupling of alkenylsulfoximineswith Rfln. The chiral alkenyl sulfoximines 2 , o b t a i n e d b y r e a c t i o n o f a k e t o n e w i t h e n a n t i o m e r i c a l l yp u r e ( R ) - L i (3, 105-106;5,23t) in the presenceof a metallicsalt (MgBrr, CH2SO(NMe2)C6H5 LlBr, ZnCl) undergo highly diastereoselectivecoupling with RrZn or ArrZn in the presenceof this nickel catalyst. coupling of 2 with [Ro(cH,)4]rzn is equally but the yield is lower becauseof reductionby the dialkylzinc' diastereoselective,

?

) 9-BBn 2) ArBr,tiott

CH3(CHr)5CH:CH, % 1 )9 - B B l s 2) (E)-CrtrOl

CH3(CHr)5CH:CH, ff

This coupling can also efiect qclu

CH,CH:Cll"

cuHr"TsYH

(cH3)2N [

1'MgBr2'cuH'vH

-# . (CuH')'Zn

]l

R'AR'

R'AR'

2

(-99Vode)

Br

C.H,CHCH:CHCH nt

I I. Erdelmeierand H.-J. Gais,Am' Soc.,111,1125(1989)'

' N. Miyaura,T. Ishiyama, H. Sasaki. V r1r, 314(1989). Dichlorolbis(l,2.diphenylphosphino)ethanelnickel,NiCl,(dppe)' cross-couplingo! RMgX with alkadienyl sulfides.t This coupling is the final The first stepinvolvesaddition stepin a new route to (E,Z)- or (Z,E)-L,3-dienes. provide alkadienylsulfides.The to phenylthioacetylene to of (Z)-dialkenylcuprates2 of configuration. with retention couplingproceeds c#isc=

cH + (c2H5cH:cH)rCuLi -+

c2H5cH3cncn3cHSC6H5

Dichlorobis(triphenylphosphine)p* Cyclopentenones. Negishiand cr of dienyl iodides(13, 103-104)ro cai route to cyclopentenones. Thus carb by Cl,Pd[P(CoH,)J,(1) resultsin rtx mediatea. n-C.H,, :

NiClz(dPPc)

2 + EEO(CHr)uMgBr +

CTH,CH:CHCH:CH(CHzLOEE ('lE.9Z,977o)

u

'

\

_^_.2

co. MCIJ' r. cHf\c,

\-cl

2

Letters, I V. Fiandanese, F. Naso,L. Ronzini,andD. Rotunno,Tetahedron G. Marchese, (1e8e). 30,243 (1984)' 'M. Gardette, N. Jabri,A. Alexakis,andJ. F. Normant,Tetrahedron,40'2741

Dichloro{l,1l-[bis(diphenylphosphine)]ferrocene]palladium'PdCl(dppf) ' coupting of B-atkyt-9-BBN with Arx and vinyl halides.t This coupling can (3 be effeciedwith Pdclr(ddpf) as catalystand a base,NaOH, K2CO.,or KrPOo but coupling, this undergo to known are equiv.). A number of B-alkylboranes couplingswith B-alkyl-9-BBNhave been examinedmost thoroughly'

Lower yieldsobtain in carbonvla

Dichlorobis(triphenylphosphine)pdladiun(Il) ldirm

(1). lel. Cl;Ni(dPPP) r. The chiral alkenylsulfoximines e n a n t i o m e r i c a l l yP u r e ( R ) - L i prelenceof a metallicsalt (MgBrr' B c.upling with RrZn or Ar2Zn in 1i I *rrh [RO(CHr)4]rZnis equallY se ol reductionby the dialkylzinc'

t \,;.

cHr(CHr)rCH:CH,

l) 9-BBN 2) ArBr, N!OH, THF, 65" Pd(tr) 70-90%

t23

Ar(CHr)rCH,

1 )9 - B B N

cH3(cHJ5cH:a", ryryIt

(E)-cuH,cH:cH(cHr)?cH3

This couplingcan also effectcyclizationof bromoalkenes:

ll3;"3ilsl''" (Yrr,rH:cHz @

CuH,VH

tl

Ver

R'ARt

C.HTCHCH:CHCH:CI ;7 +ar",

(-99Vode)

Br

i .- - , r I N. Miyaura, T. Ishiyama,H. Sasaki,M r 1 1 , 3 1 4( 1 9 8 9 ) . Ittel. \rCll(dPPe). This couPling is the final tlfdes.t ne. The first step involves addition r : rrovide alkadienyl sulfides' The 0.1

l

: H.CH3CHCH:CHSC6H5 .,

Dichlorobis(triphenylphosphine)palladium(II). Cyclopentenones.Negishiand co-workersrhaveextendedtheir carbonylation of dienyl iodides(13, 103-104)to carbonylationof unsaturatedallylic halidesas a route to cyclopentenones. Thus carbonylationof the dienyl chloride 2 catalyzed by Cl,Pd[P(CoH,),]r(1) resultsin the cyclopentenone3, probably via the intermediatea.

'',o =C:lCH:CH(CHr)6OEE -=-.92.979o) r .-: D. Rotunno, TetahedronLetters, (1984)' n- .^' . Tetrahedron,40,2741

:ae palladium' PdClr(dPPf). td rinvl halides.t This coupling can a :i.!'. NaOH, KrCO,, or KrPOo (3 n.u:r to undergo this couPling, but rn::ld most thoroughlY.

>f 2

"",JlilIffi,fffi* ["'">q-"cH,coocH] noI n_CoH,r-6,|_cHrcoocH3 \-\o \ l 3

Lower yieldsobtain in carbonylationof dienyl chloridessuchas 4.

Dichloro(pcymene)triphenylphosphineruthenium(II)

n-CuH")<,H --+ 'Ctqcl 50% HzcJ

n-CoHtra

+ HC= Cbo-NHCHTCOOH

/-\

cH3ooccH'-)r o 5

cotEting oI RtBr(Cl) with RzSnBut.2 Alkyl halides couple with 2-(tributyl(2) in the presenceof this Pd catalyst(equation stannyl-a,4-aimethyl-2-oxazoline

(r) Bu,sn{

'

,lu-1t", }a", b-2

+ (cHr)p:c(-

pd(n) -rCH, .=5 ^/CHt (cH3)2c:c-1--N. -Br I-

oJ

2

-cH,

-cH'

I).Surprisingly,aroylchloridesreactwith2intheabsenceofacatalysttogive in high yield (equationII)' bis(N-aroyl-4,4-dimethyl-2-oxazolinylidenes)

I C. Ruppin,P. H. Dixneuf,andS. lrcol

Dichlorodicyanobenzoquinone( DD( Oxidation of chiral esten of ) vertedinto acetatesof mandelicesre whenca reactionis diastereoselective 8-phenylmentholis the most useful. group has slight efiecton the diasren a donor-acceptorcomplexbetrleen of a hydrogenatom. The acetoxvctq face.

COAr I

CH".

(rr) 2+2tucocr,-*#H;{"><.}:l: COAr

IE.Negishi,G.Wu,andJ.M.Tout,TetrahedronLetters,29'6745(1988)' 'M. Koiugi,A. Fukiage'M. Takayanagi, H' Sano,T' Migita'andM' Satoh'Chem'Letters' (1988). 1351

Dichloro(p-cymene)triphenylphosphineruthenium(Il)' Ru(II) Isopripenyl estenof N-protectedamino acids. In the presenceof the catalysi, cbo_ or Boc_aminoacids add to propyne at 100. to provide isopropenyl not add estersin 55-85Voyield with no racemization.unprotected amino acidsdo in ethyl to the alkyne. Theseestersreact with primary aminesat room temperature acetateto afford amidesin75-90V0 yield.

RC6H4CI{rCOOR(R* = E-phcnykncd

Aryl ketonesor aldehydcs.r Rc aceticacidcan resultin carbonylprod H,O resultsin the ketone2. beliera positionfollowedby acid-catal;"zed h is oxidizedto a ketone bv DDQ.

^-ry)or'.rr (A,J *L

!r

Dichlorodicyanobenzoquinone

D$

o

4-c6Hr3\

r-\

Cbo-NHCHTCOOH + HC:CC4

1.00CCH,1,/ tl

o

#t c6H5cH2NH2 or4 -''- | Acoc2H5 J

J

o

tl

lr. halidescouplewith 2-(tributyls.iric of this Pd catalyst(equation

Cbo-NHCHTC-NHCHTC6H5 rC. Ruppin,P. H. Dixneuf,andS. Lecolier,Tetrahedron (19gg) Letrers,29,5365

;i

./cH3

_+ (cHrLc:c1__Nr-crq I O-fCH,

D ::c ;rbsenceof a catalYstto give t hrrh rreld (equationII).

Dichlorodicyanobenzoquinone (DDQ). oxidation of chiral estercof phenylacetic acids.t rhese esterscan be convertedinto acetatesof mandelicestersby oxidationwith DDe in aceticacid.The reactionis diastereoselective whencarriedout on estersofchiral alcohols,ofwhich 8-phenylmentholis the most useful.The presenceof substituentson the phenyl group has slighteffecton the diastereoselectivity, which dependson formation of a donor-acceptorcomplexbetweenthe substrateand the quinonewith removal of a hydrogenatom. The acetoxygroupthen entersfrom the opposite,more bulky face.

COAr

I

)-'tr. \\

,*> l-CHt 6^cH,

co.{I Lz::.' 8.6745 (1988). T \1 :rta. and M. Satoh,Chem.Letters,

DDe,HoAc ?o' ---'tr -e RC6HI|HCOOR* RC6H4CFLCOOp* (R* = 8-phenylmenthyl)

(62_67Vo de)

Aryl ketonesor aldehydes.2Reactionof arylalkaneswith DDe in aqueous aceticacidcan resultin carbonylproducts.Thusreactionof I with DDe in HOAcH,o resultsin the ketone2, believedto be formed by acetylationat the benzylic positionfollowedby acid-catalyzed hydrolysisto the corresponding alcohol,which is oxidizedto a ketoneby DDQ.

o bmrlll. cids. tn the presenceof the Ru(II) p^:. rt 100"to provide isoProPenYl aminoacidsdo not add !'1;,1.rtected room temperaturein ethyl at ur.rrc:

O.p=b*^".$]*#

ti

Dichloroketene

This oxidation also oxidizesmethylarenesto aryl aldehydes.

AAzcH, l l l

f t ( " ' . * . * oq;1 '*

7n ''L'cHo l l l

l

\A*AscH.

- l eoco cH3o^,4.2

cH,o^.^.y'

l t l

C6H5SO2 O

qI

I

Alkylaryl azides.3 Reactionof an alkylarenewith DDQ and N,Si(CHr), in CHCI, at 25'results in replacementof a benzylichydrogenby an azidegroup to give an alkylaryl azide in 50-95Voyield. Hydrazoicacid can be usedin placeof azidotrimethylsilane, but this reactionis generallyslower.

!'n' 4>*oH I ll

ooq,ru,s,1c',;, cHcr3 fr><)o" ) | ll 8t%

curo\,/

+ DDHe

cH3o^./

Benzyliccyanotion.l The combinationof DDQ andSi(CH.)3CN(1) in CH2CI2 or CHrCN effectsbenzyliccyanationof alkylarenes.

(equationI). A similar reactionof d to the system(2) of physostigminc a

'J. P.Marino,M.-W. Kim,andR. L:rr CN

I

(yr,r,

a1 er,c\

cH3oA,/

6e%

(yr

cH,oA,/

r", *. * Nc

os(cH.). lA. Guy, A. Lemor, D. Imbert,and M. Lemaire,Tetrahedron (1989). Letters,30,327 2 H. Lee and R. G. Harvey,l. Org.,53, 4587(1988). 3 A. Guy, A. Lemor,J. Doussot,and M. Lemaire,Synthesb,900 (1988). a M. Lemaire,J. Doussot,and A. Guy, Chem.Letters,1581 (1988). Dichloroketene. Butyrolactones,t Reaction of dichloroketene with an N-protected 3-sulfinylindole provides a synthesis of an indoline-fused butyrolactone in 35-40% yield

o tl

I

c6H5so2

o

i c6H5Si

( r ) l l l l l Nl

Curr...Z,...cH, J.,l"ot3}, prl i l l

lc

tun'\-\-."11

SR ctzc=c=o,

\

l, 1-Dichf oro- l- phenyl-212,2-trirreffg is preparedby reactionof (CH.).Sr|,4-Disilylation of enoncs.2 ln undergoes 1,4-addition to a,g-enon6 whichcan be convertedinto lithium c reactloncan provide B-hydrox1. kero when catalyzedby Clrpd[(+ )-BI)iAl

T'!J c6H5so2

l H

c6H5so2

i oli

, / \tcH, cH3'

.".,

l 58% I

|

c^lL qH

CH,,

tur,

1,1-Dichloro-l-phenyl-2,2,2-trimethyldisilane

cl qH,l CH. I rt

pl;.Jehydes.

d ffiTo r\ANFTT-lr V*#d scn" N--.cHt

.z-..*zl-O -l SCH, c6H5so2

l l l

c6H5so2 o

"&'r", 6s% ai[t^Fo 9*4o' r)Ar/He

9E

-l'

H c6I!so2

1

I cn"mt".x* too* xrso+J

r \rrth DDQ and N3Si(CH3)3in br.lrt'rgen bY an azide grouP to ic .l.rd can be used in place of

CH"

Sl()\\c f.

t

i

\,

c.H.- -N"

y'<:/"'tou ,

\-,/ (1) in CHzCL ) ,rJ Si(CH.)3CN

t

c6H5so2 cH' )

+ DDHQ

ll

l

N+-NAo l H l

(equationI). A similar reactionof the 2-sulfinylindoleI providesan intermediate to the system(2) of physostigmine alkaloids.

t.

lJ. P.Marino,M.-W.Kim,andR. Lawrence,J. Org.,54,1782(1989). C\ NC

-CI{CH. I

NC osi(cH3)3 ht :. " n Letters,30, 327 (1989). i.', . qU (1988). l:.. le88).

1,1-Dichloro-l-phenyl-2,2,2-trimethyldisilane, (1). The reagent CuH.ClzSiSi(CH.). is preparedby reactionof (CH.).Si-Si(CoH,). with hydrogenchlorideand AlCl..l 1,A-Disilylationof enones.2 In the presenceof Pd[P(C.H,)J.,this disilane undergoes 1,4-addition to a,B-enones to give1-(phenyldichlorosilyl) silylenol ethers, whichcan be convertedinto lithium enolatesby exchangewith methyllithium.The reactioncan provide p-hydroxyketones.The Michaeladditionis enantioselective when catalyzedby Cl,Pd[(+)-BINAP] (12, 53-57).

l, Pd(o),

c,H",ao'

CuHt-.,Zr,r(CH,

i o

urrh an N-protected 3-sulfinylbu:\rolactone in 35-407o yield

l

CH,/\CH,

ol-i

CuHr-ar1a.CH, I

cH3Li >

t t l c6H5sicl'osi(cH3)3 L

fs'

9H'

t'"'Y}t"ll c^H.si

,

J

I

- -cHrr :)6w

cuHt-"A.cH, : c6H5si

ll o

CH,/\CH, (antilsyn>20: 1)

]lfil.l

cuH'-*\.cH' i

t

l

o H o

l

tA

Dichlorotris(triphenylphocphinc)ruthenium

' E. Hengge,G. Bauer,E. Brandstatter,andG. Kollmann,Monatsh.Chem.,lM,887 (1975). 2T. Hayashi,Y. Matsumoto,and Y. Ito, TetrahedronLetters,29,a147(1988);idem., Am. ,Soc.,110,5579(1988).

(1). Dichlorotris(triphenylphosphine)ruthenium Intramolecular Kharaschr-type cyclizations.z Unsaturated c,a-dichloro esters or carboxylic acids undergo cyclization in the presence of various transition metal catalysts,particularly Cl,RuIP(C6Hr)r], or ClFeIP(OCrHs)3]3.3Thus ethyl 2,2dichloro-6-heptenoate (2) in the presence of 1 cyclizes rapidly to the cis-1,2-disub-

cl 0)\

,-f,cooc,n, ul Ka",

r, 1550 ----+ 60-7W

/\t.coocrHs ,/ I

\

|

H c4cl

.ff-""]

9,l0-Dicyanoanthracene (DCA). Triplex catalysis.t 1,3-Cyctohc der usualconditionsalthoughit is kr ence of a sensitizer.Actually. 1.3-c with a silylenote [4+2]cycloaddition ene (1). Similar resultsobtain *rrh r 2\ I \-/

Ear cd':l rt

crr l + c H '" : C / u t -osi1cH,;,

2 7 hrs. 3(cisltrans= lil) " =1:4) 16hrs. (

2ra

(3-5Va)

*,d:lo"';i;,W".ff-l

cycloadditionsinvolve a complex(tnp and the dienophile.When 1,4-dio.an reactionwith 1, the ratio of + 2laddl [4 essentiallyonly [2+2]adductsform lt

4

5

Pho tocycliza ti on of enoncssrlrria (>320 nm) of thesesubstrateswirh D(

(4Vo)

The corresponding stitutedcyclopentane, andepimerizesslowlyto the trans-isomer. (5) In both (4) the same conditions. under acid cyclizesto the crs-bicycliclactone casesonly a trace of cyclohexylproductsare formed. This radicalcyclizationcan providebridgedand fusedcyclicsystems. Example:

O

A I \.,\-

O

cooc2H5

A I

\1

(cHJ3SiCHr\/

an \)ct-f-c,

,rv,DcA ctt:9-{(n"

ll

7

8

I

r,rss'

Bzl

cooc2H5 (r2%)

' C. Wallingand E. S. Huyser, Org. React.,13, 91 (1963). 2T. K. Hayes,R. Villani, and S. M. Weinreb,Am. Soc.,U0, 5533(1988). 3 S. D. Inel, A. D. English,C. A. Tolman, and J. P. Jesson,Inorg. Chim. Acta,33, 101 (1979).

A

V

| \-*',

<

;-Si(CH,), .CH,

%

9,l0-Dicyanoanthracene

nri.r.. .\lonatsh.Chem., f06, 887(1975). ,a I t:ters.29, 4147(1988);idem., Am.

I t!.: Unsaturatedct,c-dichloroesof varioustransition 1 :!:.r Dresence ('. Thus ethyl2,2Fe[ P(OCrH5)J..3 r to the cis-1,2-disubrapidly crc.rzes

Ooc.Hr t.c,

a

'51'j'"", + CH,-g/coHs ' -osi1cH,),

.ff"".,"]

=.lr

\-/

Boqa

0,,'.,, rt7a::l;,,.,do''*',* 2 (exolendo = l:1)

(3-5Vo)

= . : t-

at

I

l\.' l

Il

t

J

LCI

Photocyclization of enonessubstitutedby an u-silyramino grcup. Irradiation (>320 nm) of thesesubstrateswith DCA as sensitizerresultsin N-heterocvcres.

tt9o) The corresponding thc :'.rru-isomer. u:rJer the sameconditions.In both brned. I .:rJ fusedcyclicsystems.

o

o

tl

I

,rrv, DC

ll

t"'o" ii",

\-,,1r

,.\

t

l

78%

(cH3)3sicHr\,,

|

\*/ Bzl

I

Bzl

) -coocrHs

3 (exolendo = t : l)

cycloadditionsinvorvea comprex(triprex)composed of the sensitizer,the diene, and the dienophile.when 1,4-dicyanonaphthalene is usedas the sensitizerin the reactionwith 1, the ratio of [4+2]adductsdecreases relativetothe[2+Z]adducts; essentiallyonly [2+2]adductsform when benzophenone is the sensitizer.

-'l

l,'Y"' -cooHl I

+|

ng

9,lO-Dicyanoanthracene (DCA). Tripl* catalysis.t 1,3-Cyclohexadiene does not undergocycloadditionsunder usual conditionsalthoughit is known to dimerizeon irradiationin the pres_ ence of a sensitizer.Actually, 1,3_cyclohexadiene can undergoboth [2+2]_ and [4+2]cycloadditionwith a silyl enol ether suchas 1-trimethyrsiloxy-1-phenylethylene (1). similar resultsobtain with trimethylsilyrketene acetar.These sensitized

+

o tl

A

(129o) (l+:,

-\.. ll0. s533(1988). . P ri\son,Inorg.Chim.Acta,33,101

I

V

-+

ll

| \-*r.

/-Si(CH3)3 'CH,, (7 l%o)

13{f

DicYdobexYlbonne

rN.AkbulutandG.B.Schuster,TetrahedronLetters,2g'5125(1988)' 2W. Xu, Y. T' Jeon, E. Hasegawa,U. C. Yoon, and P. E. Mariano' Am. 5oc.,111' 406

(1e8e). (DCB)' Dicyanobenzene Photosensitizedcyclobutanation.|Conjugateddienesandenamidesundergo photosensitizedcrossadditiontoprovidecycloadducts,whichcanbehydrolyzed tovinylcyclobutylamines.TheseSecondafyaminesundergoabase-catalyzedrear,ung",n"n.togivecyclohexenescorrespondingtotheDiels-Alderadductsofthe diene and the enamide'

Dicyclohexylcarbodiimide-Dimethyb Macrolactonization. This versro specificallyfor lactonizationof I to (.

:,EC : H ' C

HO HOOC

I

('n

,rrl (E,E)

ftv.DCB

firtt ll

cHrcN

+ HCa ZCH'-? N I

t"r-..,-., ln'

H L kNCocH3 'H tl

CHr/

cHft

( 3 . 5 l: )

'G. E. Keck.E. P.Boden.andM. R l*r

Di(cyclooctadiene)nickel(0), Ni(COD 14+4lCycloadditions. This rerr a cyclooctane-containing terpenoidl5 tainedby reductionof the t-alkvl alk_

t-tto' --0"" | ros. *n*n, Hoctl,ctl?oH I KH, THF A

NHCH3

CH, (endo)

er%

gH,> H I 1i

o CH,

kNHCH3 -H

CH:CH,

l)L^Dt+ L 2) Rcd-L Cl

CH,

CHr/

CHt

(3.2:1)

rN.L.Bauld,B.Harirchian,D.W.Reynolds,andJ.c'white,Am'soc''110'8111(1988)'

DicyclohexYlborane. R c H 2 c N . T h e s e p r i m a r y n i t r i l e s c a n b e o b t a i n e d i n 7 } _ g S v o y i e l dofb y h y followedby addition droborationof a terminal alkenewith dicyclohexylborane amount of Cu(acac),,which is an excessof CuCN and Cu(oAc), and a catalytic yield. The overall processeffects not essentialbut which markedlyimprovesthe anti-Markownikoffhydrocyanationof l-alkenes"

*"1""t, Iffi*5 tRrR'cH-cHrr*r, RrR2c:cH2 R'R'CHCH2CN

rY.Masuda,M.Hoshi,andA'Arase,t'C'S'Chem'Comm''266(1989)'

\H, |,'[?i*,cx ,fH' CH,

6?q

cH

Di(cyclooc,ladiene)nickel(0)

:::i {1988). E \t.rriano,Am. \oc.,111, 406

Dicyclohexylcarbodiimide-Dimethylaminopyridine(13, 107-108). Macrolactonization. This version of Steglich esterification was developed specificallyfor lactonizationof I to ( + )-colletodiol2.

CHr

drcnesand enamidesundergo rtr. *hich can be hYdrolYzed rearmJcrso a base-catalyzed of the adducts r Drels-Alder

HO HOOC

'cH,

I

I

I -\COCH3 .H

- lKoH,l-llo" ' . -' tt,*tl' HocrlcqoH J

(+)-2

' G. E. Keck,E. P.Boden,andM. R. Wiley,,/. Org.,54,896(1939). Di(cyclooctadiene)nickel(0), Ni(COD),. This reactionprovidesan enantioselective [4+4lCycloadditions, synthesisof a cyclooctane-containing terpenoid(5). The opticallyactiveprecursor(3) was obtainedby reductionof the r-alkylalkynyl ketone I with lithium aluminumhydride Sn(CHr),

!1,-.-

CH:CHz

,, I .NHCH" ..-_____r{ 'H

l) LiAtH4,D@on atc.(97%) ^tr 2) Red-Al.ClSn(CHrh(839o) Ln?

CHt

9H,

1."

CH, l2:1)

l\ l:::. .'lm.Soc.,110,8111(1988)'

-W*"",

CH, Fr:c,l in 70-98Vo Yield bY hYItlr.rne followed by addition of ;irrrullt of Cu(acac)2' which is ciJ fhe overall Process effects

67%

CH,

C4

CuCN'0+20"

,*, :gH#%

CH, CH,

R'R,CHCH2CN

CH, or,': . 3fr6(1989)

o

: l l l) Dcc,DMA',DMAp.Hcl oAA4o 2)H',cH,oH , i I 62qo g4€"'/l\/".cu, : O H HO

H3

QH,

(l1

132

Diethylaminomalonate

modifiedby Darvon alcohol in >98Voee. The alcoholwas convertedto the bisintramolecularcyclizationto 4 in 67Vo diene 3, which undergoesnickel-catalyzed yield. Remainingstepsto 5 includeconjugatereduction(copperhydride), hydroboration,and oxidation.

CH.

lP. A. Wender, (1988). Am. Soc.,110,5904 N. C. Ihle,andC. R. D. Correia,

C^l Dicyclopentadienylyttriumchloride, CprYCl. Preparation.I Fulvenes.2CprYCl reactswith aldehydesor ketonesin DME at 80'to form fulvenesin 60-95Voyield. S. Husinec, V. Savic,andA. E I

o ll

CprYCl C2H5CCH3+ ;;-

a

.cH.,

(r-.lar",

Diethyl oxalate,(CTH,OOC):I

rR. E. Maginn,S. Manastyrskyj, Am. Soc,85,672(1968). andM. Dubeck, ' C. QianandA. Qiu, Tetrahedron (1988). Letters,29,6931

Dicyclopentylboryl trifluoromethanesulfonate'(c-CsHe)rBOTf(1). t:ans-Glycidicesters. The Darzenscondensation'usuallyprovidesa mixture are obtainedby condensationof of trans-and crs-products.Only the trdr?s-esters with aromaticaldethe dicyclopentylborylenolateof cr-bromo-/-butylthioacetate hvdes.2

Ethyl 2-oxo-3-alkcnoaus, I reactwith diethyl oxalatein TtIl estergroup of diethyl oxalateto

CH'CH:CHMgBr M. Rambaud, M. Bakasse, G.

O

ll ArcHo+ BrcHrisc(cH,), #F

-Q[ nrMsc(cH3)3

I M. Ballester, 283(1955). Chem.Revs.,55, 2R. P. Polniaszek (1'989). andS. E. Belmont,Syn.Comm.,19,221

$( Diethylphosphono)-2-bcrcrd Preparation:

(CrH,O)P(O)CHTCH : CHCHTOI

Diethyl aminomalonate. I3+2lCycloaddition to pynolid.ines. The reaction of diethyl aminomalonate with formaldehydecan generatean azomethineylid (a <+ b) which cycloaddsto to form pyrrolidines. 1,2-dipolarophiles

.re+ HJ.TCH(COOCTHT),

\

/-\O

[CHr:1gg111gooc2Hi)2-

Dienals.t The cyclohexylir THF to give (E,E)-dienatsin 65providetrienalsproceedsin gerrc

T. Rein,B. Akermark,andp. Hclq

l-(Diethylphosphono)-2-butenal

a,c,,hol was converted to the bisur.,,iecular cyclization to 4 in 67Vo rtJuctron (copper hydride)' hydro-

133

cH,:ftHa(COOC,H')rl b ^ - | cxt=cgq996t"t 8 4 E o^l '

+-

r ,. . f10,5904(1988).

l-:

C"H.OOC \ (/ ) \<-coocrH5

\p/

\ca.,ralion.' (\: \clr)nes in DME at 80o to form

-coocrH,

H S. Husinec, V. Savic,andA. E. A. Porter,Tetrahedron Letters,29,6649 (1938).

4y EL

\,,

^rCH' -C,H,

-{-: \trc..35, 672(1968)' .rr 1

rl

, , . - t I I , ) , B O T (f 1 ) . !:r..:llrrnrusuallyprovidesa mixture tr. .::J obtainedbY condensationof with aromaticaldetL:. :hloacetate

Diethyl oxalate,(CTH,OOC),(l).

o tl

Ethyl 2-oxo-3-alkenoates,RCH:CHCCOOC2H5.' Vinyl Grignardreagents reactwith diethyl oxalatein THF/ether (1 : 1) at - 80" by 1,2-additionto only one estergroup of diethyl oxalateto form the esterof 2-oxo-3-alkenoic acids.

o o a",a":csJ-loc,u,

CH,GH:CHMgBr +I #

M. Rambaud,M. Bakasse, G. Duguay,and J. Villieras,Synthesis,564 (1988).

^ o

,u lt rr#sc(cH3)3

!-

o

tl

S(Diethylphosphono)-2-butenal,(C2H'O)2PCH2CH:CHCHO (1, EIZ : g:1). Preparation: I

le :]

(1989).

c,'r (c,H5O)P(O)CHTCH:CHCHTOH # hc :r.rctionof diethyl aminomalonate to 11;grltd (a e b) which cYcloadds

t

c6HrNH2 fr (C6H'O),ijCH2MNC.H,,-, +2

Dienals.t The cyclohexylimine(2) of 1 reactswith carbonylcompoundsin THF to give (E,E)-dienalsin 65-80Voyield. The reactionof 2 with c,B-enalsto providetrienalsproceedsin generallylower yield (25-45Vo). [Ctl

:rCH(COOC2H5)za

T. Rein,B. Akermark,andP.Helquist,ActaChem.Scand.,42B, 569(1983).

Wl

Diholomethyllithium

Diethyl thioxomalonate, FC(COOC2H5)2 (1). This reagent can be generatedin situ from the Bunte salt (2) prepared by reaction of diethyl chloromalonatewith sodiumthiosulfate. (CrIOOC)rCHCI + NqSrO, -r

In contrast,transmetallationof ) CuCl increasesthe instability.

rT. Kaufmann, R. Fobker,andM. ttcr

(CTHTOOC)TCHSSO, Na' 2

Annelationof 1,3-dienes.' The salt2 undergoescycloadditionwith 1,3-dienes adductswhich undergoring contractionto cyclopentenes to providesix-membered when treatedwith LDA or KN[Si(CH,)Jt and CH3I.The ring contractionis equivalent to a [1,2]Wittigrearrangement. Examples:

*' eo!33!;x' .",4::;"n,G!33i'x',r, -e+' xl.ttsitcrrtr)r, oo I Ln3r

Dihydridotetrakis(triphenylphoqt Isomerization of alkyncs.t Thi nationwith Bu,P catalyzes isomeriza at 80-100"in yieldsgenerallyof abo

I D. Ma and X. Lu, Tetrahedron l-cncn-

Dihydrogen hexachloroplatinrte(tl) I nnamo lecalar hy drosi ly lo tin. propargylalcohol(1) undergoes inrra to give a cyclic(E)-vinylsitane (Jf l (4) by hydrogenperoxideoxidationq ination/bromodesilylation with inr.e

I

I

Afcooc,u,

CHr-

HNISTII.cH .

n-cuH,rc:c(cHr)roH

{f\.cooc,Hj \ra",

ror,rrvrr /Cr, <.COOCzH, fl -COOCru, +l---------' ' ^ | I l-COOC,H.-----? | n -cooc'H5 Toqo ts* .^,-. -.,-,\---CH, (r "4 \'z (CH3)3SiO o)\,rs O\ra""

Br

n-ce*nf(cH2)2oH ts

H

t S. D. Larsen, Am. \oc.,110,5932(1988).

5 Dihalomethyllithium. Transmetallation.t XTCHLi reagentshave limited use becauseof thermal instabilityeven at - 100".However,transmetallationof CltCHLi with Ti(O-i-Pr)l providesthe ate complexCl,CHTi(O-t-Pr).Li(f), which is stableat 0o.Moreover the ate complex,unlike the carbene,showsconsiderablegroup selectivityfor aldehydesand cr-aminoketones(equationsI and II).

K. Tamao,K. Maeda,T. Tanaka.andy

2.2'-Dihydroxy-1.,1'-binaphthyl ( I ). Resolution of sulfoximines.t All ;omplex formationwith ( + )- or ( - I

OH

0) c6HicHo+ cuH,cocH,+fto

o

cuH,iHcHCl, H

I ll , -.n. CH3CCH2N(CH3)' (II) CH3iCHTN(CHr)2+ C2H5COC2H5 # CHCI,

(l)

o tl

ArS-R tl NH

+ (+r-l

(+)-2,Ar = m-CH,C.H. R=CHr

2,2'-Dihydroxy-1,1,-binaphrhyt

canbe generated . Thri reagent ln .rf diethyl chloromalonate with bn gH.ooc)rcHSSor-Na' 't

f,eoescvcloadditionwith 1,3-dienes p nnq contractionto cyclopentenes lll I The ring contractionis equiv-

CHr-*A,ZCOOC2H5

-

ll

l:

\.'s

l-cooc,H,

l3S

In contrast,transmetallationof XrcHLi with crri(o-r-pr)3 and especialrywith CuCl increasesthe instability. ' T. Kauffmann, R.

Fobker,andM. Wensin g, Angew.Chem.Int. Ed.,27,943(l9gg).

Dihydridotetrakis(triphenylphosphine)ruthenium, RuH,[p(CoH,),].(1). Isomerization of alkylesJ This complex (1) or IrH,fp 1i-V:rj,1,'127in combi_ natronwith BurPcataryzes isomerizationof 2-ynoicestersto 1ze,iE;-iienoic esters at 80-100"in yieldsgenerallyof about g}_gdVa. ' D. Ma andX. Lu, Tetrahedron Letters,30,g43(19g91. Dihydrogenhexachloroplatinate(IV), H2ptCl6.6H2O, 1, g90. Intramolecurar hydros,yration. The hydrodimethylsilyl ether (2) of a homo_ propargylalcohol(1) undergoes intramolecurar hydrosilyiation.ututy).aly H,prct. t:.qiu: a cyclic(E)-vinylsilane (3). This can be convertedto a B-hydroxyketone t4) by hydrogenperoxideoxidationor into (Z)-3-bromo-3-decene-1-ol (5) by bromrnation/bromodesilylation with inversionoi i"orn",.y. n-c6Hr3c=c(cHr)roH HNtsiH(cHrhtz, RC=c1g11r;rosi(cH3)rH 1 . , _r*.1urv.c4

L .. r xvfr

ir

.+ i'

I cH,ct,. 25"

Y

--\

'

-COOC,Hs f Xcooc'Hs 04

'scH3

Br

.l "n-C.-H ""'"Yt(cH,),oH H

r) 8b

.#

r_)H C.I{.CHCHCI, OH t:

'CH3CCHzN(CH3); ': l cHCl2

_

9H, | CH,-Si-e u "\>.- |

ovqall

| -

..^.._ o ll Te#' ----rn_cuH,rCHrC(cH2)20H

)

12%.. overarr

|

5

rc .:mrteduse becauseof thermal ll;:r.'n of Cl:CHLi with Ti(O-i-Pr). t ' u hich is stableat 0o.Moreover nrri:rable group selectivityfor allll

-

4

R 3

K. Tamao, K. Maeda, T. Tanaka, andy. Ito, Tetrahedron Leuers,29.6955 (lgllti). 2,2'-Dihydroxy-l,1,.binaphthyl(1). Resolution of surfoximinesJ Alkyr aryl sulfoximines(2) canbe resorvedby complexformationwith (+)_ or (_)_1 (equation I).

(I)

o tl ArS-R tl

cllta.2s" + (+)-l -F=ff-

NH

(+)-2,Ar = n-CH,CuHo, R=CH:

G)-2+ (+)-r-\+)-2 (9O9oee)

l: I

_^_ | t) cryshllizdion

/w'J2'' NeoH

(R>(-)-2(r00voee)

136

2,2'-Dihydroxy'3,3''bis(triphenylsilyl)1'l'binaphthyl-Trimethylaluminum

The efficiencyof the resolutionis dependenton the Ar and R groups,beinghighest when Ar is m-tolyl and R is CH: or CrH.. No complexis formed when Ar is CtH. and R is cH3 or from dialkyl sulfoximines.However, some dialkyl sulfoximines can be resolvedwith (+)- or (-)-3, 1,6-di(o-chlorophenyl)-1,6-diphenylhexa-2,4diyne-l,6-diol.This reagentis availablecommerciallyas Chiral Host Ace'2 CuH.Cl-o

QuHoCl-o

cuH,-E-c-c-c-c-i-tu", OH

OH

CI3CCHO + CH':Q1QP.;.

I K. Maruoka,T. Itoh,T. Shirasaka. anrjH I K. Maruoka,Y. Hoshino,T. Shirasa\a. er ( le88).

Diisobutylaluminum2,6-di-r-bu(vl-l.rr Diastereospecific reduction of et t lichenmacrolide( + )-aspicilin(4) is rhc dienol 3 with Yamamoto'sreagenr( I I OsOoand pyridinefollowed bv HS red

3 I K. Mori andF. Toda,Chem'Letters,1997 (1988)' : UbeIndustries, Ltd., Tokyo,JaPan' 14, 462,2'-Dihydroxy-3,3'-bis(triphenylsilyl)1,1-binaphthyl-Trimethylaluminum, binaphthol 1. The 47. Thesetwo reagentsreactto form the aluminumnaphthoxide

(1) ])o,.", si(c6Ht3 by conversionto the bis(triphenyl' is preparedrfrom 3,3' -dibromo-1.-1'-binaphthol /-butyllithiumto 3,3' -triphenylwith sitytoxy;ether,whichrearrangeson treatment Al(cH3)3 of sityt-i,t,uinaphthol (80-95Vo yield). Reaction this binaphtholwith dibromobinaphstarting the of prtvides the naphthoxide1. Both optical isomers with a chiral thol are known, or racemicI can be resolvedby a kinetic resolution ketone. Asymmetricene rcactions.2 The reaction of alkeneswith prochiral, electrondeficientaldehydescanfurnishopticallyactivehomoallylicalcoholswhencatalyzed In the by (+)- or (-)-1 and in the presenceof activated4-A molecularsieves, is complex organoaluminum of the absenceof the sieves,a stoichiometricamount yields' essentialfor high chemicaland optical CH"

t -

C6F5CHO+ C,-SC6H5 tl CH,

( R ) - 1 , 4 -MAs 'iii'ii::;;i:, s8%

c6F5y,.\r,sc6H5 |

ll

OH CH, (EtVoer')

G. Quinkert, N. Heim,J. Glenneberg. U. D G. Zimmermann, J. W. Bats,andG. D0ra

Diisobutylaluminum hydride (DIBAH t. II y droa lam ination of a-t- bu toxlcla .!her of propargylyicalcohol or of rhc Jrnationyieldsexclusivelythe correspon t )n the other hand, if the t-butoxygroup

Jrirtth!

Diisobutylaluminum hydride

hluminum

r \r rnd R grouPs,beinghighest nr,.\ is formedwhenAr is CoH' rc\.r. somedialkYlsulfoximines orr.r henyl)-1,6-diphenylhexa-2,4nrl.r as ChiralHost Ace'' C.H.Cl-o

-----^-+ CI3CCHO+ CHr:Q1g11:)z 'L leco

I37

ClrCtln'CHa I

oH

ll

cH,

eel [(S),78Va ' K. Maruoka,T. Itoh, T. Shirasaka, and H. Yamamoto,Am.,Soc.,110,310 (1988). r K. Maruoka, Y. Hoshino,T. Shirasaka,and H. Yamamoto,Tetrahedron Letters,29,3967 ( 1988).

-c-c6H5 Diisobutylaluminum2,6-di-t-butyl-4-methylphenoxide (l), 9, 17l. Diastereospecificreduction of an enone.t A key step in a synthesisof the lichenmacrolide( + )-aspicilin(a) is the reductionof the oxodienelactone 2 to the dienol 3 with Yamamoto'sreagent(l) in 967o yield. Dihydroxylationof 3 with OsOoand pyridine followed by H,S reductiongivesthe triol (4) in 40% yield.

OH

fthl l-TrimethYlaluminum, 14, 46un: nrphthoxide1. The binaphthol I, C6H{CH1 _-.j--j-----:-'

96%

L .

KH

(T)

ft br ;onversionto the bis(triphenylrr: :. :-butyllithiumto 3,3'-triphenylr .': rhis binaPhtholwith Al(CHr)' r:. ..f the startingdibromobinaph' br : krneticresolutionwith a chiral t: :ikeneswith prochiral,electronhr:..allylic alcoholswhencatalyzed the ir'::.1 4-A molecularsieves'In is comPlex t .-: :he organoaluminum

'-

c.r. -rzL,sc,Ht l t l oH cH' (887o eB)

G. Quinkert, N. Heim,J. Glenneberg, U. Doller,M. Eichhorn, U.-M.Billhardt, C. Schwarz, G. Zimmermann, J. W. Bats,andG. Dtirner,Helv.,7l,1719(1988). Diisobutylaluminum hydride (DIBAH). Hydroalumination of a-t-butoxyalkynes.I Hydroaluminationof the o-r-butyl cther of propargylyicalcohol or of the homopropargylicalcoholfollowed by ioJinationyieldsexclusivelythe corresponding (Z)-vinyliodidesbecause ofchelation. On the other hand,if the t-butoxygroup is separatedfrom the triple bond by three

2,2-Dimethoxypropane-Tin(Il)chloride

givesexclusively(E)-vinyl or more methylenegroups,hydroalumination/iodination iodides.The /-butoxy group is convertedto an acetoxygroup by reactionwith AczO/FeCl,in ether in 87-93Voyield. This hydroaluminationis a usefulreaction for synthesisof severalpheromones. 1) DIBAH

HC:c(cH2)"oc(cH3)3

2)tz

62J4%

> ICH:CH(CIL),OC(CH3)3

l, co+ 65.5o

(2, >99Vo)

n=1,2 n = 3-10

(8, >99Va)

I A. Alexakisand J. M. Duffault, Tetrahedron Letters,29,6243(1988).

are preparedin 98Diisopropylcrotylboronates,1..Thesechiral crotylboranates 99% ee from diisopropyltartrate. COO-i-Pr

P<

o (roo-r-Pr

I

CHt*".o/".."oo-,-r,

(ut,

(E)-(R,R)-l (98%ee)

/""coo-i-n

CH3 (Z)-(R,R)-f(997oee)

reactionsreithRCHO.| (E)-1 reactswith aldehydesto form Diastereoselective the anti-adductwith high selectivity(95-99:5-L), and (Z)-l' showsequally high is somewhatlessin the However,the enantioselectivity selectivityfor syn-adducts.

- *{r^.", ceHrecHo (E)-l

(z)-r

* .r",f^.",

cH,

>99:1

8 8 Veoe

1:99

CH, 824oee

of both (E)- and (Z)-l decreases caseof (Z)-1. Moreover, the enantioselectivity in reactionswith p-alkoxyaldehydes(72-85Voee) and aromaticor a,B-unsaturated aldehydes(55-77Vo ee). I W. R. Roush,K. Ando,D. B. Powers, Tetahedron andA. D. Palkowitz, R. L. Halterman, 29,5579(1988). Letters, 2,2-Dimethoxypropane-Tin(Il) chloride. Isopropylidenation.r Reaction of o-glucono-1,4-lactone(1) with 2,2-dimeth' oxypropanecatalyzedby SnCl in DME resultsin the ketal in57Voyield. Periodate an attractivechiral cleavageof 2 leads to (R)-O-isopropylidineglyceraldehyde,

synthon.This route via o-glucoa usualroute via p-mannitol.

G. J. F. Chittenden, Rec.Trav..lJ

I, l.Dimethoxypropene, CH.CIF 2r2-Dimethoxyoxetancs.t In hydroxyaldehydesto give 2,24u, hydroxy-3-methyl-D-lactones and activelactonewasobtainedin &)9 OAc CH3CHCH2CHO + CHrCH:C(fr

1,1-Dimethoxypropene

(E)-vinYl on r\ esexclusivelY k \\ group bY reactionwith rn::.ttion is a usefulreaction

gHroH

"o-

Vo\^,.li}r.,,ffilf,, 3ir:x37Zo\ \o "

Y

:lr,cH:)"OC(CH3)3

fo'

si%

OH

l, oo+ 65.5o

Y

fo

^

OH

2, ao+ 76"

Z. >WVo) '-. >99Va)

r--:

\o"

I Ndo. 7r%JNHcq

cHo

r l9tt8).

kowt",

l__oncH,

are preparedin 98xrrr.:rJt€s

3, co+ 63o

n--2

coo-,-Pr

/""COO-t-Pr

-.8'

synthon.This route via n-gluconicacid is economicallymore attractivethan the usualroute via o-mannitol. G. J. F. Chittenden, Rec.Trav.,f07,455(1988).

i r - R . R , - l ( 9 9 V oe e )

to form I rc.'ctswith aldehYdes a:; rZ)-l showsequallYhigh lessin the c.::\ 1I! iSSOmewhat OH

I s'^-'-Acn" r' |

"

CH,

1,l-Dimethoxypropene,CH3CH:C(OCH.),. Supplier:Aldrich. 2r2-Dimethoryoxetanes,r In the presenceof ZnClr, this ketal reactswith phydroxyaldehydesto give 2,2-dimethoxyoxetanes, which can be convertedinto 4hydroxy-3-methyl-D-lactones and 5,6-dihydro-2-pyrones. In one case,an opticaily activefactonewasobtainedin80vo ee from an opticallyactive1-hydroxyaldehyde.

9A. CH3CHCH2CHO+ CH,CH:C(OCHr),

zrctz,

82Voee

b...th(E)- and (Z)'l decreases nJ rr(rmaticor a,B-unsaturated

[-cH,oc-ocH,-cH2-cH-o

I

H

L

Tetrahedron . ::- .\. D. Palkowitz,

l..i-.-tclone(1.)with 2,2-dimethDeieral in57VoYield'Periodate rr.Jeh\de, an attractivechiral

cqtrocH3l

sMI l ) K o H fzix'o.

(oYo

\,Acr

""o' '* (o\o

Y.", OH

I

ocH3l

DL.tr l4l)

Dirnethylaluminum 2,6di'r'butyh4'methylphenoxide

crt

OCH(CH3)OCrHs CuHr:.rO-ZO

----+ cuH,CH-cucHo oI?

t

I

cH'"Y

cH,

r., lvn *I 1 " ' * * ' cHo

cu'

oH

(anti)

( 4 :l )

BE.O(qH+ I (cH3tAl DAD MAD

and R' J' F Nivard' J'c's' Perkin l' 2315 rR. G. Hofstraat,J. Lange,H. W. Scheeren, (1e88).

(L)' (R,R)-(+ )-2'3'Dimethoxy'N,N,N',N''tetramethylsuccinamide m.p.61-62',ca * 115'' coN(cH3)2

u-l-ocs,

in a further increasein endo-selectivitr. B MAD [methylaluminumbis(2,Gdi-r-bur ers the endo-selectivity. The usual rule of endo-selectiitv is m pentadienewith methacrolein(equationll enhanceero-selectivitybecauseof stericI

cH3o-f H coN(cH3)'

cH'

(rr) O.t-.",- L

I

tartrate by reactionwith diThe reagentis preparedfrom (R,R)-(+)-diethyl and 2,2-dimethoxyprosulfate (dimethyl methylamiriefollowed by methylation pane). (2)' The succinamide1 forms Resolutionof 2,2''dihydroxy-1,1''binaphthyl The temperaturein benzene/hexane' an insoluble1:1 complexwith (t)-2 at room (s)-( - )gel furnishes silica on complex after recrystallizationand chromatography from the filtrate' 2of l00Voee. (n)-(+;-Z of ft\% ee can be obtained (1988). andM. Niven,Chem,Leuers,1371 lF. Toda,K. Tanaka,L. Nassimbeni,

Dimethylaluminum 2,6'di'r'butyl'4'methylphenoxide

(DAD)'

CHO

(cq)!Al 64* DAD 67* MAD 76*

the diene, rather than by an electronicel dienophile,as in the reactionwith acroh An even greater steric effect of thc I organoaluminumreagents4-6 in the Dicl diene(equationIII). OCH" I

tn"\-/

cE (1)

(cHJ2Al-o

5 5 '

Bu-t Diels-Aldercatalyst.TheDiels-Alderreactionofcyclopentadienewith gives a mixture of'endo- and exo' acrolein (equation I) catalyzedby BFr etherate is improved by use of trim_ethylaluadductsin the ratio g: 1. The endo-selectivity aluminum by use of DAD results minum. Introduction of a more bulky group on

rllll

l)qHjctlo'* t-

2)cF{mtl ---

i (cH3)3siocH" +4 +5 +6

72* 9r% u%

Dimethylaluminum2,Gdi-r-butyl-4-methylphenoxide

ol O.

Q H r N c6H5cH3'-?8o' Nu ,fl ^ ' >

vr

CH

cHo

+ exo-2

I cHo endo-2

f ; . . / . C ' .S .

BF3.O(qHs)' (cH3)3Al DAD MAD

Perkin 1,231'5

ride(1),

\D r.

H

^

N

N

/\\ /\\ (u)[=/ . li"' ----lD-__l.cHo _+lD-[cr, ?-.", 5:r iuo J", J"o

arc h) reactionwith diand 2,2-dimethoxYPro-

n a . , .i 3 7 1( 1 9 8 8 ) .

9:1 24: I 32:1 1 2 :I

in a further increasein endo-selectivity. But useof the evenmore hinderedcatalyst MAD [methylaluminumbis(2,6-di-r-butyl-4-methytphenoxide), 13, 203-206]towers the endo-selectivity. The usualrule of endo-selectivity is not observedin the cycloadditionof cyclopentadienewith methacrolein(equationII). In this reactionboth DAD and MAD enhancee.ro-selectivity becauseof stericrepulsionbetweenthe bulky catalystand

C

te :uccinamidel" forms The in renzene/hexane. ca gel furnishes(S)-( ),m rhe filtrate.

46% 577o 52Vo 56Vo

exo-3

endo-3

+ (CHr)rAl 64Vo DAD 67Vo MAD 769o

1 5 :I 24:.1 49:1

the diene, rather than by an electroniceffect involvingthe carbonylgroup of the dienophile,as in the reactionwith acrolein. An even greater steric effect of the Lewis acid catalystis observedwith the organoaluminumreagents4-6 in the Diels-Alder reactionsof an aldehydewith a diene(equationIII).

ocH t

cHtJ (lll)

l'

(cH"),sio^

3

a1u

l o4ac6H5

I cH3

oi *cloPentadiene with nr\ture of endo- and exo:d r\ useof trimethYlalurn br use of DAD results

".,,-Z\o

"".\4o r)c6H5cHo'€L tr "t'"*n ' t

+ o

cH3 72% 9r% 84Vo

l : CH, trans-7

cis-7

+4 +5 +6

l

l:l t . 1

1 2 :I

c6H5

DimethYloluminum

' K. Mikami.T.-P.Loh. andT. Nakai.Icrn

Dimethyldioxirane,12, 413; 13. 120. Arene dioxides. Arene dioxides I polycyclicarenes,but someidentifiedn ides.Arene dioxidescan be obtained\ bondcomparableto the 9,I0-doublebo with dimethyldioxirane(f), but in mod by this method,but can be obtainedrr

4,R=CHr 5' R, = Me.,-t-Bu 6, R = CeHs 1453(1988). lK. Maruoka,K' Nonoshita,and H' Yamamoto'syn. Comm.,18,

Dimethylaluminumtrifluoromethanesulfonate,(cHJtA-loTf' - .:^-^ Gtyorylateeneneactions.Thediastereoselectivityoftheenereactionofmethyl acid be controlled by the choice of the Lewis glyoxylate (L) with 2-b";;; (2) can quanin proceed with either (E)- or (z)-2 catalyst.Reactions""t"1;;;;';; Sncr, The reactioncatalyzedby (CHJtAlCl tative yield and fairly t"gi'y'-t"ft"tivity' particularlyin the reaction anri-selectivity, proceedsin low yield tszij uut *itr, high CH"

t " ? cH2cr2QH, CH tl * u d c o o c n r 4 l l CH

l

I

c

H

CH, ) D

z E

z

CH"-

oH

|

r

Y A

ocH3 *

ll

lOocu,

iH. b sYn-3

antlS

82:18 72:28 2l:79 9;91

1007o lNVo 29Vo 65Vo

SnClo SnClo (CH3)2AIOTf (CH3)2AIOTf

OH

4

in the dimethylaluminumtriflate' particularly with (E)-2. Higher yieldsobtainwith case of (Z)-2.

:

^r +L^ .i.r- nhoin n

Thisenereactioncanbeusedtoeffectsynthesisofthesidechainpresentln (equationI)' the plant growth brassinosteroids

coocH3

CH:-cH.il (l)

\

\ I

l

l

o (cHl),Alcl

l+HCCOoCH, (2)

61E"

(anti, lC0To)

Aflatoxin Bt epoxide,2 This epor carcinogenicity of aflatoxinB,, has ber

Dimethyldioxirene

143

' K. Mikami, T.-P. Loh, and T. Nakai, Tetrahedron Letters,29,6305 (1988).

Dimethyldioxtuane, ll2, 4\3; 13, 120. Arene dioxides. Arene dioxideshave not been identifiedas metabolitesof polycyclicarenes,but someidentifiedmetabolitesmay be formedfrom arenedioxides.Arene dioxidescanbe obtainedby reactionofpolyarenescontaininga double bondcomparableto the 9,10-doublebond of phenanthrene(suchas2) by oxidation with dimethyldioxirane(1), but in modestyield. The dioxide5 cannotbe obtained by this method,but can be obtainedvia a trans,vig-bromoacetate.r

ICH.

(1988)' | ( n m . . r E ,1 4 5 3 t( Il r-AlOTf. c':rrrlr of the enereactionof methyl ei :r the choiceof the Lewis acid x: t:)- or (Z)-2 Proceedin quanbY (CH)rAlCl r3.,.lroncatalYzed in the reaction r.:.\ rt\ . particularly

xH,

CH' lly

+

l

$ . 5 , b " '6q "% "%

OH I ryocH3

CH,

l

l

o

^ v

sYn-3

l) NBA LiOAc 2)NBs 3) NaOCHI 6Va

il: l8 -2:28 ll:79 9:91 4

5

in the t.-::'rnumtriflate,particularly in Tr:-r-r. rrf the sidechainpresent )

Aflatoxin 81 epoxide.z This epoxide (2), which may be responsiblefor the carcinogenicity of aflatoxinB,, has beenpreparedby reactionof aflatoxinB, (1)

o-o

coocH3

(anti, 1007a)

(cH1bc=o #

l4

N'O-DimethylhydroxYlemine

with thoroughlydried (molecularsievesor Krco3) solutionsof dimethyldioxirane in acetoneor cH2cl2. The epoxideis very sensitiveto water, but can be storedat -10.. The epoxide(2), the first known epoxideof a tetrahydrofuran,reactsvery with the guanineunit of DNA to form an adductat the Nlposition. specifically ' under a variety of RNCO -+ RNOr.3 Ozonedoesnot reactwith isocyanates mixtures' Surgives complex conditions;oxidationwith KMnO, or CIC6HaCO3H in acetoneaffordsnitro compoundsin surprisingly prisingly,oxidationwith oxone@ i,lgf, yi"fO. from both aromatic and primary, secondary,and tertiary aliphatic p*.uiro.r. Water is an essentialingredient,probablybecausethe oxidationprois ceedsthrough the carbamicacid, which then losesco, to give an amine that be can oxidation this the immediateprecursorto the nitro compound.The rate of byo addition greatly _ A t N Hincreased z.-->ArN z . a T h i sof o xTriton i d a t i oB.n c a n b e e f f e c t e d w i t h d i m e t h y l d i o x i r a n e generatedin situ from oxoneoin acetone(1-1.,442).However, in somecasesthe intermediatenitrosoarenecan be the major product, especiallywhen a limited amount of Oxone is employed.In such casesthe yield of the nitroarenecan be improvedby addition of certainaromatics,suchas indolesor furans. (1) Nifioxides.s Cyclic secondaryaminesare oxidizedby dimethyldioxirane

llvll . CHr'.|

coNH;l

l-

lrCH,

I T. Hanamoto and T. Hiyama, T.t)

cH,../-\zcH, ,

l

I o.

OH

-..

+ CH'C

coNH2

, t*rzrrlo,o'rp?::,;;'.".Ad.""

OH

o ll (CH.1"6:9116p--ocu,' -a",

l,3.Dimethyl.2-imidazolidinoc flX

to nitroxidesin yields >95Vo. coNH2

productsare reducedto g.Mihy ethyl(methoxy)borane.

Ullman ether synthesis.t m-p condensation of z-hydroxybenz_v d and8-hydroxyquinoline (a). Thc yr highestin DMI.

"o\

/--.,

cH,rl

lzcH,

cH,A54cH, #.n,AT^.", o.

rS. K. Agarwal,D. R. Boyd, W. B. Jennings'R. M' McGuckin,and G' A' O' Kane' Leuers,30, 123(1989). Tetrahedron 2 S. W. Baertschi,K. D. Raney,M. P. Stone,and T. M. Harris,Am. soc., 110,7929(1988). r P. E. Eatonand G. E. Wicks,,r. Org., 53,5353(1988). 1D. L. Zabrowski.A. E. Moormann,and K. R. Beck,Jr., Tetrahedron LeUers,29,450l ( r988). 5 R. W. Murray and M. Singh,ibid.,29,4677(1988).

LL, 201-202. N,O-Dimethylhydroxylamine, p,6-Diketo esters.t Various N-methoxy-N-methyl amides couple with the dianion of alkyl acetoacetates to form B,6-diketo esters in 42-9lVo yield. These

UFcH,oH

+ ql DMF DMSO DMI

R. Oi, C. Shimakawa,and S. Takcoe

Dimethylphosphinothioyl chloridc, r Peptide syzdresis in mertotol e hydrides prepared from N-protedc alcoholsin the absenceof a base.p sequencethese active esters can h

Dtunethylphosphinothioyl chloride

\'.utronsof dimethYldioxirane I '.' \\ater.but can be storedat i .: :ctrahYdrofuran'reactsverY a: ,r,lductu115s\LPosition' undera varietyof I r.,)c\anates i'{ rr\d\ comPlexmixtures' Surin surPrisinglY nr:r,, comPounds c\\:.Jrr). and tertiarY aliPhatic the oxidationProa!..r trecause 11( (). to give an amine that is fhs r.rteof this oxidationcan be lits.:cJ with dimethYldioxirane l, llowever,in somecasesthe du;: especiallYwhen a limited : rrti,j of the nitroarenecan be !. i:lJolesor furans. (1) rr;rzc,JbY dimethYldioxirane

) \ l t ' ll

/.coNH2

i r l , cur.rnu'cH' H

7

l

.l

a""AN " l

cn,

o.

productsare reducedto 8,6-dihydroxyestersby NaBHo in combinationwith diethyl(methoxy)borane.

o

Yt-ocu'

fl fl

lli'fl

(CH.),C:CHCN+CHTCOCHTCOOBu-I -cH, #(CH,),C:CHdCUTCCnCOOnu_, "

N!aH1 | (c2H5)2BocH3, JrHFrcH3oH

OH

OH

: cH\-'t'-(CH,)rc

cooBu-I

synlanti>95 :5

I T. Hanamoto andT. Hiyama,Tetrahedron (1988). Letters,29,6467

It-Dimethyl-2-imidazotidinone (DMI),

-*/c't 't | \NAo

0), tl, Z0Z.

CH, Ullman ether synthesis,t ru-Phenoxybenzylalcohol (3) can be prepared by condensation ofz-hydroxybenzylalcohol(2) with chlorobenzene catalyzedby cucl and 8-hydroxyquinoline (a). The yield is markedlydependenton the solvent,being highestin DMI.

2

It

1.15

DMF DMSO DMI

2r% 58% EI%

3

\tcGuckin,and G' A' O Kane'

d li.:rrrs.Am. Soc.'1f0,7929(1988)' F\ Leuers,29,450l irr ir Tetrahedron

' R. Oi, C. Shimakawa,and S. Takenaka,Chem.Letters,899(1988).

S

tl Dimethylphosphinothioyl chloride,CIP(CH3),(1.).

-rr.r:hrl amidescouplewith the diIr. :.rr-rsin 42-9lVo Yield' These

Preparation.' Peptide synthesisin methanol or ethanol.2 The dimethylphosphinothioicanhydridespreparedfrom N-protectedamino acids with 1 are stableto water or alcoholsin the absenceof a base,probablybecauseof the I,:S bond. As a consequencethese active esterscan be used for peptide synthesesin methanol or

L6

Dirnethylsufoxide-Phenyldichlorophosphate

ethanolratherthan the dipolar aproticsolvents(HMPT, DMR or DMSO) usually required.The report includesa synthesisof a heptapeptideby this expedient.

cH2cr2

.,/\

I

llal

- z o + z r/ r l

\-/

' M. Ueki,T. Inazu,andS. Ikeda,Bull. Chem.Soc.Japan,52' 2424(1979). ' M. Ueki,T. Saito,J. Sasaya, ibid.'61'3653(1988). S. Ikeda,andH. Oyamada,

804

CH3(CHJ"CH:CH, n=11or15

Dimethyl sulfoxide-Chlorotrimethylsilane. Cleavageof a,p-epoxyketones.t The reagent(1), possibly(CH,)rSCl'formed from DMSO and ClSi(CHr)r, cleavesa,B-epoxyketonesto 2-chloro-3-hydroxy ketoneswith high regioselectivity(equationI). If the epoxidehas a phenyl subketonesare formed (equationII). stituent,3-chloro-2-hydroxy

cl \ .cH3 H O-.1\zo .

o I, CHTCN,25' 9l%

ctr(cE),

(rr)

A/COCH3 CuHt

t

V

l

cH(cH3)'

c l o t t l

' F. Ghelfi,R. Grandi,andU. M. Pagnoni, J. Chem.Ras.(S)' 200(1988).

Dimethyl sulfide-Dibenzoyl peroxide. 'these ethers(6,1O9-\\S) canbe prepared Methylthiomerhyl (MTIlf) ethers.l by reactionof alcoholswith dimethylsulfide(8 equiv.) and dibenzoylperoxide(4 equiv.) in CH.CN at 0" (75-90Voyield). Excessdimethyl sulfideis requiredsince someof the sulfideis oxidizedto dimethyl sulfoxide. rJ. C. Medina,M. Salomon, (1988)' Letters,29,3773 andK. S. Kyler,Tetrahedron

i (C6H5OPCI2)' dichlorophosphate

Dimethy!sulfoxide-Phenyl p-chloroalkyl sulfides.t A reagent(1), obtainedfrom DMSO and cuHsoPocl: with alkenesin which the methylthiogroup in CHrCl, at -20",forms trans-adducts carbonatom. is attachedto the less-substituted

F

I H.-J. Liu and J. M. Nyangulu, Tetrahedrott

o

Dimethylsulfoxonium methylide,CH,:i Cyclopropanationof lactams.t Th$ 2 (13, 18-19) to form endo-cyclopropana are hydrolyzed to optically active c-vclop

""'Y"oqu \,o7rt q,.uYA_ +

7c.",Yc",

I OH

\

I

o , R=H R = CcHs

644o s8%

t 95t 931

A. l. Meyers,J. L. Romine, and S. A. Flcu

Dimethyl 1,2,4,5-tetrazine-3,6-dicarbox

The tetrazineis preparedin severalsteps Diels-Alder reactionslpyrroles.. n :ronwith unactivateddienophilesto form rhich are reducedby zinc in aceticacid r i.5-dicarboxylates.

Dimethyl 1,2,4,5-tetrazine-3'6dicrrboxylete

7\ I

{\tPT. DMF, or DMSO) usually ptulc-PtidebY this expedient' t;i' 1l.l:

cH2cr2 ^,"'tt l l+ 1 - 2 0 + 2 0 " ) l I

,os' 9ra",

\-/

s2.2424(1979). t b r d . . 6 1 , 3 6(5139 8 8 ) '

cH3(CHt"cH:CHz

rou"*

Cnr(cH2)"9H-CHTSCH3

n=tlorl5

formed nr , 1 r. possibly(Ctt,)'3Ct' 2-chloro-3-hYdroxY n icr.',nesto subi: rhe ePoxidehas a PhenYl I I ) ' rc q u a t i o n cl , .cH3

0 )-yo

I

v/I

cH(CH3)'

o cl ll '\z'^cH, 'r., I OH , . 5 ) .2 0 0( 1 9 8 8 ) .

L47

Cl

I H.-J. Liu and J. M. Nyangulu,TetahedronLetters,29,5467(1988).

fl

Dimethylsulfoxonium methylide,CHr:S(CHr), (1). Cyclopropanationof hctums.t This reagentaddsto the chiral bicycliclactams adducts(3)in>93Vo de. Theseadducts 2 (13, 18-19)to form endo-cyclopropanated (4). are hydrolyzedto opticallyactivecyclopropanes

CHr-OzcHrgg,

CH,-OzCHrg11,

Voi--n A,^ly^* -!

.fr$ii^, cH, R

8l-t8%

cH3ooc

o

o , R=H R = CcHs

\P-N \*\.4i l '

64Vo 58Vo

3 95Vo ee e 93Vo

A. I. Meyers,J. L. Romine,and S. A. Fleming,Am.$oc.,110,7245(1988).

be I c::.rr\ (6. 109-110)can PrePared peroxide(4 dibenzoyl and ,j ..r't.) since r.- .:'methylsulfideis required il:.'r.Je (1988)' t ""',t1 Letters,29,3773

(J

il : , .tl.OPCIJ. C.H5OPOCI: 1,.,...,r from DMSO and grouP methylthio the which a.\i:..r in \r

coocHr NAN Dimethyf1,2,4,5-tetrazine-3,6-dicarboxylate, ll | N-..ZN

(l),

m.p. 173-175".

I coocHs The tetrazineis preparedin severalstepsfrom ethyl diazoacetate. Diels-Alder reactionslpyn'oles.t This azadieneundergoes[4+2] cycloaddi:ronwith unactivateddienophilesto form dimethyl I,2-diazine'3,6-dicarboxylates, .hich are reducedby zinc in aceticacid with ring contractionto dimethylpyrrolei .5-dicarboxylates.

3,S-Dlnitroperoxybenzoic ecid

cH" il" 1+

CuH,

dioxu

i

coocH3

.u

s2%

v

coocH3

r+

lI CH,

------+

";H

63% ^,, Lrl

CH,

\ coocH3

NH

| )=/ \

coocH3

rD. L. Boger,J. S. Panek, (1988)' andM. Patel,Org.Syn.,submitted Dimethylzinc' Zn(CH3)2. Enolate acylation and alkylation.t The yield from acylation and alkylation of lithium ketoneenolatesis markedlyimprovedby additionof dimethylzinc.which

o tl

oLi

I

A IJ

cHrr (

;\J

)--cH'

+ HMPT 94Vo + 7n(CHr), 98%

o il

oLi

A

4

csHlTcocl 7a(CH$

ococsHr?

ccsHrT lrH,t

+

7^.

l

l

\-/

\-, (88%)

I

4

o_N

C^H., - "\./

coocH3

. ,"_Or\ r r l

cH,

If

l(5 cquia.I cH{t

.-

@_"o"syz\*

colr,/-\osi(cH3)3#

cH3\ /osi(cH3)3

cuH',6cH,

I

(tco)

suppressesa-proton exchange.The effective reagent may be a lithium alkoxYdimethvlzincate. rY. Morita,M. Suzuki, andR. Noyori,J. Org.,54'1785(1989). 3,S-Dinitroperoxybenzoicacid' (OrN),C6H.CO3H(l'). Cleavageof isoxazolinesto $-hydrory ketones.t This cleavagecan be effected acid (1) or trifluoroperaceticacid usingabout 5 with either 3,5-dinitroperbenzoic equiv. of the peracid at 25'. Use of more drasticconditionsresultsin BaeyerVilligar oxidationof the B-hydroxyketonesto acylateddiols.

&

I P.ParkandA. P. Kozikowski, TerrahedrcI (Dioctyl)sodium sulfosuccinate,

s I cH3(cH')3cH(c,H5)cH'O'CCH:CHC .( (AOT,r).

Selectivepeptide synthesis.t Thrs sur from certainaminoacidsin isooctanewau or dioctadecylcarbodiimide (DODCI). Thi hydrophobicgroupssuchasleucine.(CH.) and TrpOCH, coupleto form a dipepti& waterto the extentof LlVo,but whenAO Trp-OCH1 is formed in 60Voyield. In rlx This coupling effectedwith a surfactanrsr aminoacid are alignedat the micellarsurfr are in close promixity and that formation facilitated.Couplingis not promotedwhcr DCC or DODCI. This techniquecan be usr .rn the basicityof two differentamino acid D. Ranganathan, G. p. Singh,andS. Ranga

l.'l-Dioxene, 13, Il2-1I3. a-Hydroxy and u-keto acids.t The pr ietoneswith lithiated1,4_dioxene areoxidu :cids (2). Oxidationof the adductswith Fc

iffil=-"11, \o/

tto

o

1,4-Dioxene

cH, z^ HoAc

.IJ v6r^5\z^ ,

I

-NH

rrs equiv)cH2Cl2 C6H'3',-VCH3

CuH,r\.*CH,

I

O -N

ll

"------+

-----:^

56Eo

|

ll

OH

O

I

i2c'o

i

coocH3

\/

* lt3"r"i"l' cucL f

\ coocH3

cH,

cuH,r-a,^.oA.

I, .1r "":\4 ----------, -r+

coocH3 I NH

I ):/

C H-" ' H.

\

coocH3

L49

I

OH

* 7:3

CuH'r\ioH OAc

rP. ParkandA. P. Kozikowski, (1988). Letters,29,6703 Tetrahedron (Dioctyl)sodium sulfosuccinale, SO.Na

!J.mrtted (1988)'

ne.i from acylationand alkylation which lbr .rJditionof dimethylzinc'

ococsHrT

CH3(CH')3CH(C'H5)CH'O'CCH'CHCO'CHCH'CO'CH'CH(C'H'XCH2)'CH3 (AOT,1). Selectivepeptide synthesis.t This surfactant can effect synthesisof peptides (DCC) with dicyclohexylcarbodiimide from certainaminoacidsin isooctane/water (DODCI). This couplingis limited to aminoacidswith or dioctadecylcarbodiimide hydrophobicgroupssuchas leucine,(CH.)'CHCH,CH(NHr)COOH.Thus Bzl-Trp and TrpOCH, coupleto form a dipeptidewhen activatedwith DCC in isooctane/ waterto the extentof lTVo,but when AOT is alsopresentthe dipeptideBzl-TrpTrp-OCH1 is formed in 60Voyield. In the absenceof water, no reactionoccurs. This couplingeffectedwith a surfactantsuggeststhat DCC and the hydrophobic aminoacid are alignedat the micellarsurfacein sucha way that both polar groups are in close promixity and that formation of the activatedester intermediateis facilitated.Couplingis not promotedwhen a water-solublecarbodiimidereplaces DCC or DODCI. This techniquecanbe usedto effectselectivecouplingdepending on the basicityof two differentamino acids. \oc.,111,1144(1989). G. P.Singh,andS. Ranganathan,Am. D. Ranganathan,

(89o) alkoxydirc,:iclll may be a lithium

|

.-.
1.4-Dioxene.13. 7f2-IL3. a-Hydroxy and a-keto acids.t The products(1) of reactionof aldehydesor ketoneswith lithiated1,4-dioxene areoxidizedby PCCto affordestersof a-hydroxy rcids (2). Oxidation of the adductswith Fetizon'sreagentprovidesan enone (4), CH". OH

0 ll rl). be effected bncs.t This cleavagecan about 5 using acid rn::.uoroperacetic Baeyerin results dr,.:rc conditions to .,.\lated diols.

.,",1") \o/

CH.. OH

CH". OH

nao' ..",1ao-,.",,,o"He , .,",4oo" #tto' u 2

150

Diphenylmlenium hydloxyacetate

The reagentis obtainedby reactionof ( ( (80Voyield).Ir losesHOAc at 80.. Hypoiodite reaction.t This reaction HgO (5, 347-348).A new versionusesior selenurane,and this versiongivesessenti hydrinsor other productsencountered*itl O

O

ll

lcHryrcHC_ o(cHr)rocHo

l]

*".n>

s

ll o

AcO

which is oxidizedby PCC to an c-keto ester,which is hydrolyzedto an c-keto actd (st. IM. Fetizon.P. Goulaouic, (1988). Letters,29,6261 andI. Hanna,Tetrahedron Diphenyliodoniumchloride, (C6H,)2ICI,l, 341. ; 2, I78. Phenyl arenedithiocarboxylates.t These esterscan be prepared by reaction of diphenyliodoniumchlorideor bromidewith sodiumarenedithiocarboxylates. S S ll ll '-nrInH?no ercSCr4 nCSNa + (CuH,)rICl #

"o.xK,. (-j--,

Diphenylphosphinicchloride (7, 138). p-Lactamsfromp-aminoacids.t B-Aminoacidscyclizeto B-lactamson treatand triethylamine(1:1) in CH.CN at 80" usuallywith ment with (C6H5),P(O)C| of the amino acid. However,yieldsare rather preservationof the stereochemistry low when the amino group is primary.

I R. L. Dorta,C. G. Francisco, R. Freirc.arr ( 1e88).

OAc

o

,oAc

fr

cuffc,H, HOOC NHBzI

---;-

/H

cH4-1-con, "-Brl

O'/

Diphenylseleniumhydroxyacetate(CoHr)r*d:-ococH"(l).

(c6H5hsiH2.Fdo^ 7^Ch,THF 5EC

I-o

(G5H5)2PC[ N(c.2H5b C6H5O\

F[

Diphenylsilane-Palladiurn(0)-Zinccilorf Reduction of allylic acetates. This ,t reductionof simple allylic acetatesand er PdIP(C6Hs)3]4 is replacedby terrakis(tri-pt

I Z.-C.Chen,Y.-Y.Jin,andR.-Y.Yang,Synthesis, 723(1988).

C6H5OWH

i

/l

I-

o.JL-).",--

N. Greenspoon andE. Keinan,J. Org.53.3?a Diphosphorustetraiodide, prlo. Reductive desulfuration of dithiuccnl ietals can be effectedwith prln. Y.Shigemasa, M. Ogawa, H. Sashiwa, andH. Sl

Diphosphorustetraiodide

*t,

-r .uA/o\ \o/ {

The reagohtis obtainedby reactionof (C6H5)rSeO with aceticanhydridein THF (807oyield). It losesHOAc at 80'. Hypoiodite reaction.t This reaction is usually carried out with iodine and HgO (5, 347-348).A new versionusesiodine in combinationwith this diphenylselenurane,and this versiongivesessentiallyonly cyclicetherswithout any iodohydrinsor other productsencounteredwith other heavymetal acetates.

o

CH"I

tl cH3)TcHCCOOH

f a _

r^J r'12,,,80') atfr so%

eco\A/

"o--,^jX' l

l

\-A--l

_1::t. 178. tk' J.:drs can be preparedby reaction n:- -'Jrum arenedithiocarboxylates'

--

l'" ]

S tl r ercSCuH,

-' ,,*,

on treattr i'- 1.rdscvclizeto P-lactams with usuallY 80' at r CH.CN . rn x " rather yields are However, .rcrd. i1.'

C6HrO\

/H

cHif-l)cuu, of^-B, w.

n,n . 1242(1988).

l l {' ' )' \' r/ , t ' O C H r ( l ) .

l

?r=lr\t l l

*80% l

rR. L. Dorta,C. G. Francisco, R. Freire,andE. Sudrez, Tetrahedron Letters,29,5429 ( 1988).

Diphenylsilane-Palladium(0)-Zincchloride. Reduction of allylic acetates. This three-componentsystemis effective for reductionof simple allylic acetatesand even of 3-acetoxyglycals, particularlyif PdIP(C6H5)3]4 is replacedby tetrakis(tri-p-tolylphosphine)palladium(0).

tcu?'3Jj-l#(o)'' ^"fi ^.6 ,oAc I-O

[,'

A.o4/

I

OH

, u::.h is hYdrolYzedto an a-keto acld l i . . ' , 1 . e u e r s . 2 9 , 6 2(6119 8 8 ) '

f51

,oAc FO

d"",

';-Q.",,1, o.Jt)"", N. Greenspoon andE. Keinan, J. Org.53,3723(1988).

Diphosphorustetraiodide, PrIo. Reductive desulfuration of dithioacetals.t This reaction of dithioacetalsor ketalscan be effectedwith PrIo. (1989). Y.Shigemasa, M. Ogawa, H. Sashiwa, andH. Saimoto,Tetahedron Letters,N,1277

t52

DisodiumtefiscrrbonY[errte

carbonate' Di-2-pyridYl r,/\)

O

a\

in the presenceof Pd(O)andZnCl, they'rea in the polar solventN-methyl-2-pyrrolido

ll (r).

ll I li I \*AoAoAN/

with phosgene The reagentis obtained(907oyield)by reactionof 2-hydroxypyridine and N(C'H,)3in CHrCI/toluene'l a catalyticamount of 4Esterificationz This reagentin combinationwith for esterificationof carboxylic dimethylaminopyridine(DMAP) is very effective acidswithalcoholsorthiolsatroomtemperatures.However,reactionofaromatic andhinderedacidsrequiresseveraldaysatroomtemperature.Frenchchemists reportthatonlythismethodisusefulforesterificationoftheprotectedbaccatin Illderivative(2)with(2R,3S)-N-benzoyl-O-(1-ethoxyethyl)-3-phenylisoserine(3) reactionconductedat 73'for 100 to provide the protectedtaxoi derivative(4)' A hourswith6equiv.ofland2equiv.ofDMAPproduced4inS}vo.yield.Natural agent,is obtainedby removalof the protective taxol, a cancerchemotherapeutic groupsat Cr' and C, of 4' OR

osi(c,H.). P ,EH,I

(I) RX + NqFe(Co).

RqHrb !'

I

Example:

BuBr

r S4{ ?tt

rT. Koga,S. Makinouchi,and N. Okukado.C/r

N-Dodecylpyridoxal(DPL.r,

I C'J

Transamination. Transaminationwrti catalystsuch as Cu(II). However, transar combinationwith hexadecyltrimethylam reagentsphenylglycineundergoestransam tion I).

, R = COCH: c6H'coNH ? .n.Alort

;"' "

c6H5CoNH T**, 3 6c,H,r o__ c.H. i ocHCH3

(I) C6H5CHCOO-+ HOOCCHTC I .NH,

I

oc2H5 4 (1984)' rS. Kim, J. I. Lee, and Y. K' Ko,TetrahedronLetters'25'4943 ,J.-N.Denis,a.E.Green,D.Gu6nard,FGu6rritte-Voegelein'L'Mangatal'andP'Potier' Am. Soc.,110,5917(1988)' Disodium tetracarbonYlferrate' Aromatic ketones(cf.,4,461,

463).t The acyliron complexes (2), prepared

fromNarFe(CO)aasshown,haveratherlowreactivitywithalkylhalides'However'

c6Hrcoc0ol

H. Kondo,H. Tanamachi, and J. Sunamoro. C

N-Dodecylpyridoxal

153

in the presenceof Pd(O)andZncl, they reactreadilywith aryl iodides,particularly in the polar solventN-methyl-2-pyrrolidone (NMp).

i rl).

i-hr droxypyridinewith Phosgene

(I) RX + NarFe(CO)o

P(c6H5)3' NMP t RCOFe(CO)rp(Cu4)rl

I

pq *rlh a catalyticamount of 4re r()r esterificationof carboxylic 5 Houev€r,reactionof aromatic [n :.mperature.French chemists hr.rlr(rnof the protectedbaccatin (3) Irh,'rr ethyl)-3-phenylisoserine 100 73'for at conducted rc.ritron 4 in 80Voyield. Natural pr,..1uced of the Protective br removal inc'J

'

t

ss-as* frfic.H,y,1 z,cr" J RCOAI

Example: BuBr

r

ceHslrBuCOC5H5 'tr%

T. Koga, S. Makinouchi,and N. Okukado, Chem.Letters,ll4l (19gg\

N-Dodecylpyridoxal (DPL), (l). CH, Trsnsamination. Transaminationwith pyridoxalor analogsrequiresa metal catalystsuch as cu(II). However, transaminationcan be effectedwith DpL in combinationwith hexadecyltrimethylammonium chloride. By using these two reagentsphenylglycineundergoestransaminationwith 2-oxoglutaricacid (equation I).

o

DPL, RN(CH3)3CI

!l

(I) C6H5CHCOO-+HOOCCHTCH,CCOOH --:0''PH8_9--+

.| *NH.

H. I r a{ 1e13(1984). '\ ':irlcin. L. Mangatal,andP.Potier.

"ll o

C6H5COCOOH+ HOOCCHTCHTCHCOO-

.*", H. Kondo, H. Tanamachi,and J. Sunamoto,Chem.Letters,2013(19gg).

(2), prepared i ::r.rroo complexes flrr::r *'ith alkylhalides.However,

o cH,--NA \

tHr\ NH /

a1 cuH,

cH, Ephedrine. (-)-ephedrine hydrochloride Imidazolidinones. The reaction of urea with used as a chiral auxiliary for be can (1),r which provides a chiral imidazolidinone

"'^)r*'. "+*cH, fr-s* o

(+)-l

cHl

c#,

(-)-2

ctt

cH3- -cH3

llBl?*""",**, a\'coocH' ' (( t - t

t"'f{"'

14cu, (r)

--

l' oo-445o

(lR, 2s)

>i:i t l

effectingstereoselectivesynthesisofcitronellicacid(5).Thusreactionofl.with of a methyl cuprate the acid chloride 2 gives ihe unsaturatedamide 3. Addition an adduct (4) furnish to (12,25I) induction to 3 proceedswlth trigtr asymmetric that is hydrolyzedto (-)-citronellic acid (S)''

\ c q

(S)-f (5$t r

H. Roder,G. Helmchen, E. M. Peters. K. Pc Int.Ed.,23,898(1984). : E. Stephan, andP.Cresson. G. Pourcelot, Clr ' C. FehrandJ. Galindo, Am. Soc.,ll0. 6m I

cH3H96H5 + l +

N_CH(CH /

cHrt Y o

"-l-o" i.g,

cocl

HO \

NR.. CH,CI'

'lo%

.",.*/)^,A,"^f'cH' CH, 3 ,rn t""rh.u"rtr, S(cHrb J

""'F{t'

cH" A

Hooc ,) cH,

o li -si1cH,;,

LioH *,*

II

cH,

"r,-*/ffi"' eH, o o

( Ethoxycarbonyl)nitrene. Ethoxycarbonylamino acids.t ( Etho rhermolysisof N(ethoxycarbonyl)-N.O-b *ith ketenesilyl acetalsto form N-protect

- C-os(cHr), C -' . H';. O N-

cH,

(-)-s (4) havebeenpreprotonntion't (R)- and(S)-c-Damascone Dnantioselective paredbyaGrignardreactionfollowedbyenantioselectiveprotonationwithl'and of the ketone from (-)- or (+)-ephedrine'Thusprotonation i,'uott, availaLle (4), respectively. j-z (R)-c-damascone enolate3 with ( + )-r or 1'- turnishes(S)-or r5l

eo.

* l-(cHr)'sil' o

lLqnto 2

F

(Ethoxycarbonyl)nitrene

o

""'-nA*

H

CE

C.H

"Hr\

Hq

h cuH,

I.r-cH(cH3)' cH3 (-)-2

(+)-1

Ir: * rth ( - )-ephedrinehydrochloride rh ,.,n be usedas a chiral auxiliaryfor

\,'coocH, t l

cH'a-rceHs l !

4

..

\

/ \ N N H

.(+

CH"9Li

CH,

CH.

CH.

1) BuLi 2) CH2=CHCH2M8CI -

fr-"H,cH:cH, t

l

\

cH3

cH, 3 (ElZ= 9:r)

(+)

CHr/ Y o 1, co-214.5o

CH.

/,ril\2'" t

t

\

9cH"

ts "

CH.. -CH,?

CH"?

2dll.'J -^.n. t t

l,c. :, .rcid (5)' Thus reactionof I with ar:: .:g 3. Addition of a methyl cuprate (4) Itr - 12. 251) to turnish an adduct

' H. Roder,G. Helmchen, Angew.Chem. andH. G. v. Schnering, K. Peters, E. M. Peters, Int. Ed., 23,898(1984). I E. Stephan, Chem.Ind.,562(1988) andP. Cresson, G. Pourcelot, ' C. FehrandJ. GalindoAm. $oc.,110, 6909(1988). ,

a{t'"'

-t'r,r\ffiH' CHt

O

3 rnr, s(cH:h

.r* |t."rh.ot

iH.

(Ethoxycarbonyl)nitrene. Ethoxycarbonylaminoacids.t (Ethoxycarbonyl)nitrene(2), generatedby (L),: reacts thermolysisof N(ethoxycarbonyl)-N,O-bis(trimethylsilyl)hydroxylamine yield. (3) in25-70Vo with ketenesilyl acetalsto form N-protectedo-amino esters O

rr---'r.AA.acH'

o 1",

cH3 ee) G)-4 (707o

(S)-4(58%ee)

r)

,

-

e0. f - -- ^)i-.-sl1cu,1, -- C-OSilCHr), # -r(cH,),sit?o l c-r-'', .H.o Nl

-oS(CHrh

ol cH:.r=c<['(i''a, tl l-

LCTH5OCU

C",

{ (4) havebeenprc' anJ r S)-a-Damascone protonationwith 1' and y cnanttoselective bc.jrrne.Thus protonationof the ketone (4), respectively' [Sr- or tR)-cr-damascone

[*^::',f:'1 cooc2Hs L

# .",."cooc2H5 I

NHCOOC2Hs

156

Ethylnitrite

Chem.Res'(s), 304(1988)' I M. Antonietta, andP. A. Tardella,.'/. L. Pellacani, (1981)' 46'342 'Y. H. Chang,F.-T.Chiu,andG' Zon' I Org''

Cc I

Btlj-.

c'lL

RC6H4CH:CH2+CTHTONO R=H p = p_CH3 R = z-NOz

Ethylene glYcol. Diets-Alderrcactions.|ThelaboratoriesofBreslowandofGriecohaverep o r t e d t h a t w a t e r c a n e n h a n c e t h e r a t e o f D i e l s - A l d e r r e a c t i o n s o fal't d i e have nesthat Liotta et or similar hydrophilic groups (12' 314)' acid carboxylic iorrrs with dienes reactionsof benzoquinones examinedsolventeffectson cycloaidition group, and.report significant rate ensubstituted with a relatively hydrophobic benzene(26:1) or evento.reactionsin the hancementin ethylenegtycotretativeto solvent effect to aggregationof the diene absenceof a solvent. Tiey attribute the

Z6

\A,;

C.HTCH:CH-CH:CH:

Tl

and the quinone.

I T. Okamoto,K. Kobayashi, S. Oka.andS 1 r G. N. Schrauzer, Inorg.Synth.,ll,6l (l%t)

cH3orco

QH, CH,

Ethyl triphenylphosphonoacetate'(qH. )' Reaction wi th N -protected 2'hy&ory1 provideso'a reactionwith thesesubstrates intramolecularMichael ad base-catalyzed

ocorcH3 lu') 257o C6H6(93 (22tu') Trqo HOCHTCHpH

r-(CH")rT.Dunams,W'Hoekstra,M'Pentaleri'andD'Liotta'TetrahedronLetters'29'3745(1988)' Preparation'' Ethyl hydrogen malonate' HOOCCH'COOg'Hs reactwith ct'p-enalsin pyracid malonic of 2,4'Pentadienoot"'l Half esters with to form thesediunsaturatedesters' idine containingdimethylaminopyridine generallyhigh (2E)-selectivity'

+.t cH^..rcHo + HooccH,coocH3

cHA'A/coocH3 lZEtZZ= 95:5)

I R. E. Strube,Org' Syn'Colt' VoL IV'' 417(1963)-'. 534(1988)' ' i.' nlotigt"t'andB' waegell'Svnthesis' solution in CzHsOH The nitrite is availableas a l57o Ethyl nitrite, CTH5ONO(1)' = mono(Aldrich)' ' ^ of co(DH)' cl(Py)' [DH ---oo 1 In the presence Dresence Ketorimesfrom styrenes'l ethyl nitrite to (C'H')'NBH" styrenesreact with dimethylglyoxtt"i-o of anion yield' form ketoximesin nearly quantitative

t_(c.tL).

I\ t t A o Hl ' " *l - - - + l \ * \

l c m

I

cooR 2,n=l n=2

I

COOR 807o TlVo

3

T. Nagasaka,H. Yamamoto,H. Hayashi.V 29, 155(1989).

Ethyl triphenylphosphonoacetate

i /renr.Res.(S),304(1988) 16 r:l {1981).

RC.H.CH:CH'+

CTHTONO

R=H p = p-CH, R = rn-NOz

)r.:- .,1Breslowand of Griecohaveref lr:rr.-Alder reactionsof dienesthat ili. ::,,ups(12,3I4). Liotta et a/'' have with dienes of benzoquinones rc.:.:r,)ns rate ensignificant rePort and .;r. :: ir-': " r (16: I ) or evento reactionsin the D.\--:: cffectto aggregationof the diene

Cocar. BH4-, -"'" ) l [tHrqrrNo-l I l+CH,C:NOH CuHoRJ L saqo l-".* 969o 3J9o

NOH

4'..-\, l

l

l

l

zJ-t

-657o +.\ l

"

l

l

!

l

v

\-A'--/

+

C.HTCH:CH-CH:CHz

nqa

CcHTCH:CH-1:*On CH,

rT. Okamoto, K. Kobayashi, (1988). S. Oka,andS.Tanimoto,J. Or9.,53,5089 r G. N. Schrauzer, Inorg.Synth.,ll,61(1968). (C6H.).P:CHCOOC,H, (1). Ethyl triphenylphosphonoacetate, Reaction with N-protected2-hydroxypytolidines or -piperidines. The Wittig providesa-alkylatedpyrrolidinesor piperidinesafter reactionwith thesesubstrates base-catalyzed intramolecularMichael addition.l f u rahedron Leuers,29,3745( 1988)

*' [-tt"J" \r{

E.: It'

-:; .rcidreactwith a,B-enalsin PYr-':r thesediunsaturatedesters,with

COOR )

a - 1 - - t

r-(9HJ" |

NlH

+

to,,. \ I cooc"H.

ou

II

X x I I Preparation.'

+ l

COOR

80Vo 71Vo

3

787o 877o

[-':"'t \N

cHrcooc2H5 I cooR 4

T. Nagasaka,H. Yamamoto,H. Hayashi,M. Watanabe,and F. Hamaguchi,Heterocycles, 29, rss (1989).

| - -:- cHYvcoocH3 (2El2Z= 95:5)

|.-.

is .,. ,.iahleas a l57o solutionin CzHsOH : cx.:.i of Co(DH),Cl(PY)' [DH monoNBll. rtvrenesreactwith ethyl nitrite to c:i

3Commercial FeCl3is driedby treatmentwirh d heatedunderhighvacuumat 40o. { M. CherestandX. Lusinchi,Tetrahedron Lcdc

Ferric chloride. Dimerization of ketoneenolates. Frazier and Harlow' havenoted that ketone enolates(LDA or KH) couple to l,4-diketoneswhen oxidized by dry FeCl: in DMF. Yields rangefrom 25 to 70Vo.Paquetteet al.2have extendedthis reaction to intramolecularcouplingof a bisenolateto a cyclopropane.Thus addition of a

o

r

l

A,cooH"o*ri*., tj|r",$ \*d, cH,

r

l rN" cH,

H

Ferric chloride-Acetic anhydride, 6,260. t-Butyl ethers.t The t-butyl group is O to-hydroxyalkyllithium or Grignard reateo of the metal with the ethereal oxygen. Tl quantitativeyield by reactionin hexanesid catalystAmberlyst H-15 (Aldrich, Fluka). Deprotectioncan be effectedat 25'in {l AcrO systemin ether as the solvent.Un&t diene or enyneunits is observed.After clc the FeCl, to insolubleFePOo.

I A. Alexakis,M. Gardette, andS. Colin.Icrre

Ferric chloride-Alumina. This supportedre: basicaluminumoxide in CH'CI for one hq Ene catalyst.2 This catalystafiords hi3l in enereactions.Thusthe alkylidenemalon of dimethyl malonatewith (R)-citronellal presenceof FeCl3/AlrO3to give essentiall-v I (2). This product was convertedin scvenl

(CH3OOC)2CH'+CH,

THF solutionof the dienolateof 1 to a solution of dry FeCli in DMF provides yield. The productwaspreparedas a precursor . the cyclopropane2 in abouJ50Vo projected of ceroubenic acid-III (3), a metaboliteof certainwasps. synthesis in a with FeCl. (2 equiv.) and Cyclic amides.a Reaction of N-acetyloxyamides HOAc (1 equiv., essentialfor solubilizationof FeCl, in CHrClr) affordsa species that effectsamidation(inter- or intramolecular)of an aryl group.

/*o v\/

'"?',lr?,o"'4fro --;;,t"oo. w_^1"

'R. H. Frazier,Jr. and R. L. Harlow,L Org.,45,5408(1980). 2 M.-A. Poupart,G. Laosalle,and L. A. Paquette,Tetrahedron Letters,29,269(1988);Org. Syn.,submitted(1988). 158

s6d

CH,

cs,f ' o Hcu, 3

llr

Fenic chloride-Alumine

159

I Commercial DMF andthen with thionylchloridein refluxing FeCLis driedby treatment heatedunderhighvacuumat 40'. r M. Cherest (1989). Letters,30,715 andX. Lusinchi,Tetrahedron

rnu I l.rrlowrhavenotedthat ketone c. rrhen oxidizedby drY FeClr in c.' -;. : haveextendedthis reaction Thus additionof a I c\ri\)propane.

e"

n

: 2LDA a F{:t, tl

Ferric chloride-Acetic anhydride' 6,260. t-Butyl ethers.r The t-butyl group is the most useful meansfor protection of or-hydroxyalkyllithium or Grignard reagentsbecausethe bulk hinderschelation of the metal with the ethereal oxygen. The t-butyl ethers can be preparedin quantitativeyield by reactionin hexanewith isobutenecatalyzedby the solid acid catalystAmberlystH-15 (Aldrich, Fluka). Deprotectioncan be effectedat 25"in90-95Voyield by cleavagewith the FeCL/ AcrO systemin ether as the solvent.Under theseconditionsno isomerizationof diene or enyneunits is observed.After cleavage,addition of NatHPOoconverts the FeClr to insolubleFePOr. lA. Alexakis, (1988). Letters,29,2951 andS. Colin,Tetrahedron M. Gardette,

54%

t

i-|,I.

2'coott

Ferricchloride-Alumina.This supportedreagentis preparedrby stirringFeCl,with basicaluminumoxide in CHzClzfor one hour followedby removalof the solvent. Ene catalyst,2 This catalystaffordshigh yieldsaswell ashigh stereoselectivity reaction 1, preparedby Knoevenagel in enereactions.Thusthe alkylidenemalonate of dimethyl malonatewith (R)-citronellal,undergoesan ene cyclizationin the cyclohexane presenceof FeClr/AbO. to give essentiallya singletrans-disubstituted (2). This product was convertedin severalstepsto the optically pure cadinane QH, CH, \

(CH3OOC)rCH'* CH,

_-___>

iq: rr drv FeCli in DMF provides [r\:u.! $as preparedas a precursor 1-1 .r metaboliteof certainwasps.

CH,

82% cH,ooc

I

r:=rJes with FeClr (2 equiv.) and rf F':('1,in CHrClr) affordsa sPecies t ' : .tn aryl group.

,r* | F.ct"/Al,o. { -

scvcrd EEps

- l t l :

:' . 1980). T.::..;,:,'rlron Leuers,29, 269(1988);OrS

H

fcn. OH

CH,

CH,

160

N-Fluoropyridinium trifluoromethenesulfonrte

veticadinol(3). The ene cyclizationis usedto providethe desiredtrans-fusionof the decalinring system. I L. F. TietzeandU. Beifuss,Synthesis,359 (1988). ' L. F. Tietze,U. Beifuss, Angew.Chem.Int. Ed.,27,703 J. Antel,andG. M. Sheldrick, ( le88).

The fluorinatingpowerof this tnfla of chloro or alkoxycarbonylgroupsrr 3 are particularlypotent fluorinatingi

cr

Fluorine. Oxidation of pyridinecarboxylic acids.r Reactionof a pyridinecarboxylicacid 2-pyridone or the esterwith L0VoF in Nr resultsin oxidationto the corresponding in 50-75Voyield. An N-fluoropyridiniumsalt is probablyan intermediate.

/\at ll

COOCH3F2,cH3cN H,o.o" ----:+ | 56%

\#"ooa",

HoANAcoocH3

'M. Van Der Puy, D. Nalewajek,and G. E. Wicks, Tetrahedron Letters,29,4389(1988).

2\

-OTf (1),

rirAcr l-orf

F

2

r T. Umemoto, K. Tomita,andK. Karade 2 7 , 3 2 7 1 , 4 4(6159 8 6 ) .

..'L,COOCH, 'r rr I ll

N-Fluoropyridiniumtrifluoromethanesulfonate, (O,j

i l l

m.p. 185-187",

F sensitiveto moisture. The salt is preparedby reactionof pyridine with sodium triflate and fluorine diluted in nitrogenor helium (caution:F is very toxic and corrosive). q.-Fluorination of ketones.r This salt can fluorinate moderatelyreactivesubstancessuchas alkyl or silyl enol ethersand vinyl acetates.Of particularinterest,

Formaldehyde-Sodiumiodide. Mannich cyclization.t Reactron sodiumiodide(3 equiv.),and camphq in the piperidine2inSl-90Voyield. ln t even after a reaction at l(X)ofor ,1 L elaborationto exocyclictetrasubstitu

.I{. lf -h tH HCHO,

ic-cc", I

H. Arnold, L. E. Overman,M. J. Sharp.r

t#d" osi(cH3)3 cH.l ,-\..J,2-\/

l A.ow

l

l

CH.l ,-->],,Z...'/

* l l 10% "PY

l

F (ull = l:2) to give selectively it reactswith the trienol silyl ether of a 3,1.1,l7-triketosteroid the 9c-fluoro-3,1.1.,1.7-ketosteroid(50Voyield).

FormaldehYde-sodium iodide

D\rid Ihe desired ,rans-fusion of

r^

Thefluorinatingpowerofthistriflatecanbemarkedlyenhancedbyintroduction the triflates2 and or alkoxycarbonylgroupsinto the ring system'Thus chloro of 3 are particularlypotent fluorinatingagents'

-lfrgew.Chem.Int. Ed.,27' 703

a'l-\

ii l l - I l

l t l crAriAcr l-orr acid rir(,n of a pyridinecarboxylic 2-PYridone rrr rhc corresponding n..bablvan intermediate'

coocH3 coocH3

a \i.,

orr (1),m.p.185-187",

,F

ri coocu, l-orr

F

F

2

3

Letters ' (1988); Teftahedron : T. Umemoto, , org. syn.' submitted K. lbmrta,andK. Kawada (1986). 27,3271,4465 Formaldehyde-Sodiumiodide. I with formaldehyde' Mannich cyclization.t Reactionof the alkynylamine resultsdirectly 1 equiv') (CSA' acid sodiumiodide (3 equiv,),and camphorsulfonic is observed cyclization no of NaI' in the piperidine2inSl-9}%yield' In the absence useful for group is iodide vinylic even after a reactionat 100; for 3 hours' The bonds' double elaborationto exocyclictetrasubstituted I

i:

+,\

cH3ooc

-I

HcHo'

sr:h :odium triflate and fluorine I :, \rc and corrosive). uL'nrat€moderatelyreactivesubtl jJitates.Of particularinterest'

161

lc:cc", (* I Bzt l

^-- Cft", .Jj;;- [-rnc-ccH,lst-eo* _l(na"' \o/ I r I I II J

Lu' a

Bzl 2

H.Arnold,L.E.Overman,M.J.Sharp,andM.c.witschel'org'syn''submitted(1989)'

Fo CH'l

.-W t

t t

F :r 3 = l:2)

?-:nrietosteroidto give selectively

Glycolaldehyde(1). (2), This simplesthydroxyaldehydeis availablecommerciallyonly asthe dimer m.p.80-90".Rebeketal]havereportedthatthedimerdissociatestolinthe

s*' ;iH*i'.;.':"" ""#d, ,,.['JoH[ ;r1

B-HalodiisopinocamPheYlb tion of IpcrBH with HCI and with Ir. Cleavage of ePoxidcs- / epoxidesof cycloalkenesto 1 90% yield. When carried ou Thus the hak antioselectivity. react with the oxide of cYclo

presenceofanacid.InthepresenceofLDA(4equiv.)2reactswiththeenolate of 2 with Lt I anA ZnClrto form the lactone4 in usefulyield. A similar reaction the ketone enolateof 4 forms a keto epoxide(5)'2

o

,.c",o_g[5'*g*,"6flI";

hydrins in 22-9lVo ee. Thi t compoundsfor asYmmetric

andI N. N. Joshi,M. Srebnik.

'J. Wolfe,D. Nemeth,A. Costero,andJ' Rebek' Jr' Am' Soc'' 110'983(1988)' 2 p. Dinprasert, C. Mahidol, C. Thebtaranonth,and Y. Thebtaranonth' TetrahedronLeners' 30, 1149(1989).

3-HeptadecylmonoPerPhtb

This surfactant tYPeof a rnhvdrideadduct2 of herci

Baeyer-V illiger oxidta rnto the product of BaeYe rhthalic acid or z-chloroP

(2)' xlrrm.rcially only asthe dimer the in to f I ::f Jimer dissociates ...:i A f.-,'TfH3(3)

t-.

'ri

,--o. \ I

,no{,lo

cuHrACuH,

reacIpcrBcl and Ipc,BBr u: lt"lu"tlby reactron B.Halodiisopinocampheylboranes. from is obtained HBt' i"'p"ttively' Ipc'BI tion of IpcrBH with frCr ani

*ttn cleave ilirouo* o7,po*ra"'Aswithsimpler in Yl:::':::';,,:T#X'J#s workup' halohydrins 65nonoxidative epoxidesof cycloalkene';" ;;";;ier show high ento -100'' the cleavagecan carned";"?";'-tg 90Vo yield'when ( + )-pinene from derived antioselectivity.Thus tnJnJoriropinocamphe.ylboranes to furnish (1R'2R) haloot cy.top.ntene react with the oxide "t il;;;#-o.

4 (-l JJui\.) 2 reactswith the enolate of 2 with I r:':..1 A similar reaction

O"#q; X=Cl X=I

t:

22Voee 9l9o ee

of the use or mesoreaction is a further example This ee' in22-9lZo hydrins .ornpounOtfor asymmetricsynthesis'' Soc"110'6246(1988)' 1N. N. Joshi,M Srebnik'andH C Brown'Am' 5

'. d'\

i - : . S o c . , 1 1 0 , 9 8( 139 8 8 ) ' Letters' : ."brurunonth,Tetrahedron

(l).

acid'CH'(CH')'uO 3-Heptadecylmonoperphthalic

/1

co3H

HOOC

steps from the maleic peracid is obtained in several This surfactant type of a anhydride adduct 2 of heneicosadiene'

CH3(CH,),6-\

2 )

r-1

oAoAo Baeyer-Vitliger oxidation'L into the product "f B";;;t;ltigt' phthalic acid or --tn'"i';;";;""?"tt

p-ionone (3) selectively This peracid.converts with monopero"ioution.(5)' Oxidation of 3 of 3 or of the (a) "tto vletdstne epoxide 163

Hexamethvldisilane

S[Si(CH3)il](l). I Hexamethyldisilathiane, The reagent is prepared' most conveo sulfur with sodiumnaphthalenidein THF siru, which is then allowed to react with cl CH, S + 2Na-(C,'FIJ:+

1

9 0 :1 0 100:0 11:83

clc6H4co3H CIC.H.CO,H+ SDS I + NaHCO,

Baeyer-Villigerproduct.Addition of sodiumdodecylsulfate(SDS)to the oxidation epoxidation. acid resultsin completeregiospecific with rn-chloroperbenzoic ' Y. Fujise,K. Fujiwara,andY. Ito, Chem.Letters,1475 (1988). (1). (CH3)3SiSi(CH,)3 Hexamethyldisilane, Allyltrimethylsilanes.t The reactionof an allyl alcohol(1 equiv.)with CHrLi (1.5 equiv.) and then with l in ether/HMPT (1:4) at 80" furnishesallyltrimethyl-

o tl

(I) CH,:Q11iH + SuLi

#

(II) n-CrH,,CHO+ CHr:Q1at

BuCH:CHCTLSi(CE)3 (E) #

n-CrH,,CH:CHCHTSi(CE)3 (E)

Cyclic sulfides and thiolactorrcs.t O ' convertedinto a silanewith liberationof with Br(CHr)"Br to form cyclic sulfidcs. R chlorideprovidesthiolactones. A similar reductionof seleniumvnth a synthesisof alkali metal selenidesand dnr

' J.-H.SoandP. Boudjouk,Org.Syn.,subnr : K. Steliou,P. Salama, t- A andJ. Corriveau. r D. P.Thompson andP.Boudjouk,,Drd..Sl. :

Hexamethylphosphorictriamide [(CH.)::{ l2,3lw ittig rean'angernent.t Reactiq nose,with allyllithium(3 equiv.) in THF I reaction of the aldehydeformed in sirlr b allyllithium to give the alcohol2 as a mi undergoescompletely regioselectiveepo! (U,97-98), but with moderatediastereo

o2 c6I{5scI{r\

silanes.They are also formed from the reactionsshownin equationsI and II via the intermediatesshownin equationIII.

-Q

^n,A./ " \ l (I[) ' 1

\_J

!9

crlto

cx:=cxri '

CH,

I

r; r cax5u 2) HM'T

o'

clr+

o

-r*Gn'sll' .''''t'"''] K)*':cH, ,tnl *

o'

O=/*2si(cH3)3 Soc., 110,7252(1988)

cE+

c

Hexamethylphocphorous triemide

cH, _ cH3

'ci{

o ll

aAa'\-occH3 t t l t

t

l

l,

cHr

Hexamelhyldisilathiane, S[Si(CH3)3], (l), b.p. 91_95./100mm, toxic. The reagentis prepared'most convenientlyin g}-ggvo yield by reduction of sulfur with sodiumnaphthalenidein THF (ultrasonicirradiation)to form Na,Sjn sira, which is then allowedto reactwith chlorotrimethylsilane.

!

S + 2Na*(C,oH,)'-----* fNnSt;ff#L

-,: l0 - rl:0 .. 8-1

d,.cccrI sulfate(SDS)to the oxidation pre:. rceiospecific epoxidation. -i

r1988)

165

r

cyclic sulfides and thiolactones.2 on treatment with an alkyilithium, I is convertedinto a silanewith liberationof "LirS" (or an equivalentj, which reacts with Br(cHr)"Br to form cyclicsulfides.Reactionof ..LirS" with an ro-bromoacyl chlorideprovidesthiolactones. A similar reductionof seleniumwith a metarnaphthalenideprovides an in situ synthesisof alkali metal selenidesand diselenides.3

ar -r.lrI alcohol(1 equiv.)with CHrLi ' r . -i I ar 80' furnishesallyltrimethyl-

l: Cl{CH.Si(CHr), t t

> a-C.t{..CH:CHCH2Si(CHJ3 (E)

xr:. .hown in equationsI and II via

Hexamethylphosphoric triamide [(CH.),N].P:O, (HMPT). l2'3lwittig reanangement.t Reactionof the chirarsurfone,r, from l-arabinose,with allyllithium(3 equiv.) in THF followedby additionof HMpr resultsin reactionof the aldehydeformed in situby rossof phenylsulfinate with remaining allyllithium to give the alcohol 2 as a mixture of epimers.The anrr-isomer (2a) undergoescompletelyregioselective epoxidationunder the conditionsof Mihelich (11,97-98),but with moderatediastereoselectivity to give 3.

o2 c6H5sclt

o^4./ \ , cH,to CH,

+ ]n'Eili .'''""o']

-Q

r1r caxru I zl nri'r

o

"",+d CHt anri - 2 (43%)

cH2cr2 ". li l,"x&ff&vo(oqHt3' l

,tol

U

c4si(cH3)3

u 0 -:s2 (1988).

CII" + syn-2 (3lVo)

o "",+d CH, 3 (synlaui = 3: l)

scoH,

L6

Hydrogen peroxide.

Sequentialdialkylation.z The chiral 1-butyrolactonel canundergosequential dialkylation,particularlywhen lithiation is conductedin THF in the presenceof

H,O, (30Vo)in a basic medium provrdes H,Or.

/^ r{5)3co

(c6H5)3co ^ v

c6H5sH+ H2o2

\v6rr l) LDA, HMPr, cH3t 2) LDA, HMPT,C2H5I-

N€tt4o' I

-

59%

2 (99:l)

HMPT at -78o. Either diastereomerof 2 can be obtainedin high optical purity by invertingthe order of introductionof RlX and R2X.

rT. Kamiyama, S. Enomoto, andM. Inoue.Cl

I R. Briickner,Tetrahedron Letters,29, 5747(1988), ' K. Tomioka, (1988). Y.-S.Cho,F. Sato,andK. Koga,l. Org.,53,4094

Hydrogen peroxide-Benzeneseleninicria ATCHO --->ArOH.t Aromatic aldehr when treatedwith H,O, (30Vo)in the prer catalysts,of which areneseleninic acidsare matesare readily hydrolyzedto phenols.

Hydridotris(triphenylphosphine)copperhexamer (l) , 14,175. Preparation:

' L. Syper,Synthesis,167 (1989). Naoc(c4), + cucl

c6lr5cH3 r [cuoc(cHr),]o

P(C6H5b

"'

t

NaCl+ (CH,),COH [(CoHr)rPCuH]u+ | (50-6s%)

Hydrogen peroxide-Potassiumcarbonrtc. Or idation of 2 -nitrocycloalkanones.. (30Vo)and K2CO. in CH.OH to dicarboq whetherthe NO, group is secondaryor ter

readily in The hydride hexameras a solid is fairly stableto air, but decomposes solution.t ' D. M. Brestensky, Letters, andJ. M. Stryker,Tetrahedron D. E. Huseland, C. McGettigan, 29,3749(1988).

-

H2q, Kfq CH.OH

;;-H

c(cH3)3 Hydriodic acid. Reduction of sulfoxides to thioethers.r Use of hydrogen halides for this reductionwas first reportedin 1909and is still a viablemethod.This reductionhas assumedimportancesincechiral sulfinylgroupsare valuablein asymmetricsyntheses and are eliminatedin two steps:reductionto the ether followed by catalytichydrogenationor metal/ammoniareduction.The first step can now be carried out review (349references). with severalreagents,as shownby this comprehensive

o. No, \Jz r-cH, (

\J

)

- H

R. Ballini,E. Marcantoni, M. Petrini,andG

I M. Madesclaire, Tetrahedron, 44,6537(1988). Hydrogen peroxide. Arenesulfinicacids.r Oxidationof arenethiolsgenerallyresultsin mixturesof sulfinicand sulfonicacids,sincesulfinicacidsare easilyoxidized.Oxidation with

Hydrogen peroxide-Potassiumfluoride. a-Alkylbenzyl alcohols.t An interesru of this type from acylsilanesinvolvesenan Thus the acylsilaneI is reducedby dibora

Hydrogenperoxide-Potassiumfluoride

NCirrrBI can undergo sequential reJ rn THF in the Presence of

1:6il

HrO, (30Vo)in a basic medium providessodium sulfinates,which are stable to HrOr. c6H5sH+ Hro,

c'H'oH' NaoH'H'o' [cuHrsorNa] ror" Hct,n:o J c6H5so2H

otrarnedin high oPticalPurity R,\ . s-1.r1D](i988). lr l{.175.

rT. Kamiyama, andM. Inoue,Chem.Pharm.8u11.,36,2652(1988). S. Enomoto, acid, CuH,SeOrH. Hydrogenperoxide-Benzeneseleninic ArCHO - ArOH.t Aromatic aldehydesundergo Baeyer-Villiger reaction when treatedwith HrO, (30Vo)in the presenceof severalseleniumcompoundsas acidsare most effective.The resultingaryl forcatalysts,of which areneseleninic matesare readily hydrolyzedto phenols. rL. Syper, (1989). Synthesis,167

P(C6,H5)j

cH,,,,-je-, !rd. * (CH3)3COH

Hydrogen peroxide-Potassiumcarbonate. Oxidation of 2-nitrocycloalkanones.t Thesesubstratesare oxidized by H2O2 (30Vo)and KrCO. in CH.OH to dicarboxylicacidsor keto acids,dependingon whetherthe NO, group is secondaryor tertiary.

readilYin ::: hut decomPoses H2q, K2CO3

Letters, Tetrahedron t j \1 Srryker,

#*

4a,a",,,

[i;"

Hooc(cHr)2cHcHrcooH c(cH3)3

oi hrdrogenhalidesfor this rerb,.emethod.This reductionhas syntheses r:.u.rblein asymmetric e:her followed bY catalYtichYr:: .lep can now be carried out n.r\c rcview(349references).

'R. Ballini,E. Marcantoni, (1988). M. Petrini,andG. Rosini,Synthesis,9l5

b g:nerally resultsin mixturesof .'r.rlr oxidized.Oxidationwith

Hydrogen peroxide-Potassiumfluoride. a-Alkylbenzylalcohols.t An interestingsynthesisof opticallyactivealcohols reductionas the first step. of this type from acylsilanesinvolvesenantioselective Thus the acylsilaneI is reducedby diboraneand a chiral c-amino alcohol [(S)-

HOOC(CHr)4CCH3

tl

o

168

HydrosilanerTetrabutylammonium ffuoride

o il -3#L cH,isilcuur;,

I

C6H5(CH3)rSiH, in the presenceof Bu.\l rotrimethylsilicate(TASF, 13, 336) in ap The actualreagentmay well be a hexava and KF are far lesseffectivethan Bu.NF. X nearquantitativeyieldscan be achieved.a as in the casewith methylcyclohexanon

"\..0" cH/\si1cuH,y,

I

2 (94Voee) (95%) I Aqo, DMAP

la H

cni

C.H.

'ou

HzQ' ff CHrOH KHCOT,

soco

4

(r00so)

"\...'tu"t

o

cu/\sitcuu,y, I

tn'

*

t

OAc

l

(

,uonr.",ot

-(

3 (-)-2-amino-3-methyl-1,l-diphenylbutanol-112 to 2 in 94Voee, probablybecause of the bulky nature of the silyl group. Brook rearrangementof the acetateof 2 provides3, which is then subjectedto oxidation with retention of configuration (L2,243-244), 'J. D. Buynak, (1989). T. Hurd,andA. Phan,l.C,S.Chem.Comm.,89 J. B. Strickland, 2S. Itsuno,M. Nakano,K. Miyazaki,H. Masuda,K. Ito, A. Hirao,and S. Nakahama, J.C.S.Perkin1,2039(1985).

c6H5(cH3)rsiH 99% (c6H5)2cH3siH8l% This reduction is cnti-selective in thc n This contrasts with syn-selectivity for rrcu in trifluoroacetic acid.

o tl

c6H5ccHCH3 Hydrogen peroxide-Ttichloroaceticacid. Cleavageof acid-labile protectivegroups.l The reactionof H2O2Q07o, FMC) and CI:CCOOH in CHzCL/r-butylalcohol convertsa dimethyl acetal(1) into a hydroperoxymethyl acetal(a), which can be isolatedbut which for convenience (andsafety)is reducedto the aldehyde 2 in 80Vooverallyield. The sameconditions can effectoxidativecleavageof tetrahydropyranyland trityl ethers.

RCH(OCH3)' I

ctLcL, (cH,),coH 4q' c\ccooH '

F."{f

I

c6H5(cll3hsiH BU4NF

es%

)

cJ{

OAc

o

o

i l l l c.HlfN(c2Hj)2

'qfr

*.

CH,

M. FujitaandT. Hiyama , J. Org.,53. 5.tO55

s(cH:)2,p611g 80%

,

a

in all manipulationswith the safetyprecautionsnecessary The paper discusses hydrogenperoxide. IA. G. Myers,M. A. M. Fundy,andP. A. Lindstrom, Letters,29,5609 h., Tetrahedron ( 1988). Hydrosilanes-Tetrabutylammoniumfl uoride. Redaction of aldehydesor ketones.t This reduction can be effectedwith hydrosilanes,particularly sterically hindered silanessuch as (CuHs):SiHrand

p-Hydroxyethyltriphenylarsoniumbrod saltis preparedin 69Voyield by reacriono 2,3-Epoxy-3-arylpropanols.' The salr taininga traceof HrO and solid KOH ro fi a solid-liquid phase-transfer process.

ArcHO+ I +,

60- tvl

I

L. Shi, W. Wang, and Y.-2. Huang, Tetrahcd

p-Hydroxyethyltriphenylarsoniumbromide

H-

difluoin the presenceof BuoNFor tris(diethylamino)sulfonium C6H5(CH3)rSiH, particularly polar HMPT. solvents, rotrimethylsilicate(TASF, 13, 336) in aprotic The actualreagentmay well be a hexavalentfluorosilicateinvolvingHMPT. CsF and KF are far lesseffectivethan BurNF.With propercontrolof all the parameters, is alsopossible, nearquantitativeyieldscan be achieved,and high stereoselectivity as in the casewith methvlcvclohexanone.

OH

\ \sitcuH,), rHl 2 94Vo ee) r;O. DMAP(957o) 10o%)

I

160

c^H. \ "- s i"( c 6 H 5 ) 2 cll' ti

o

OH

CH, BuaNF, HMPr

&""'

OAc

./-'r,.CHt t l

+ l

+

I

\-, J

' | :: 2 rn 94Voee, ProbablYbecause I :frrrangementof the acetateof 2 sith retentionof configuration 111..1 (1989). P- .- I C.S.Chem.Comm.,89 r

!r

This reductionis and-selective in the reductionof a-oxy and a-amino ketones. for metal hydridereagentsand for hydrosilanes This contrastswith syn-selectivity in trifluoroaceticacid.

I:o. A. Hirao, and S. Nakahama' c6H5(cH3)2siH

?

C^H.CCHCH. I

tr"ift e)%

OAc l:.: reactionof H2O2Q\Vo,FMC) D:: r::. a dimethYl acetal (1) into a ; - .':cd but which for convenience ..'rall vield. The same conditions F 131; rnd trityl ethers. '.t-l " "1

,,)rllI

o

OH

..",1oo'o.1..,n^roo' CH,

o H o o H o : i l l l l 'N(c2H5), + cuHft c^H^-N(c,H5),- - -

o

i l l l c.HffN(C2H5)2

'

OH

CH,

I

"u\ /

76:24 94:6

c6H5(cq)rsiH 999o (C6H5)2CH3SiH 8l4a

98%

|

|

CH,

CH,

>99:1

(1988). M. FujilaandT. Hiyama , J. Or9.,53,5405,.5415 s(cH3h> RCHO 80%

2

with o .j-...uo in all manipulations Letters,29,56@ b:: ':. Jr.. Tetrahedron

p-Hydroxyethyltriphenylarsonium bromide, [(C.H').AsCH,CH,OH]Br (1). The at 110'. and BTCHzCH2OH saltis preparedin 697oyield by reactionof (CoH5)3As 2,3-Epoxy-3-arylpropanols.tThe salt reactswith aryl aldehydesin THF conraininga traceof HrO and solid KOH to form theseepoxidesin 60-85Voyield via process. a solid-liquid phase-transfer ArCHO * 1

;*;-

ACH-CHCHTOH

'o'

(ElZ = 74-91:26-9)

;,. :Juction can be effectedwith hY' td

CH,

: . : r n e ss u c h a s ( C 6 H 5 ) 2 S i Ha 2n d

Leuers,29,5295(1988). L. Shi, W. Wang,and Y.-2. Huang, Tetrahedron

170

Hydroxylamine-O-su[onic acid

Hydroxylamine hydrochloride. Pyridine synthesis.t Dihydropyrans (1), formed by cycloaddition of aryl enoneswith vinyl ethers(12,561),can serveas protected1,5-dicarbonylcompounds pyridines(2). and react with hydroxylamine(2 equiv.) to form 2,4-disubstituted CuHr... C:O CHOC"H< I , il i l l \ CHt I CuH,

o i i F ' 1"fi-tHlc-cH H2NosqH

L NOSO

I F.Lucchesini, N. Picci,M. Pocci,A. De Mun yb(fodL cH^cL

CuH, I

(R)-3-Hydroxybutyricacid (1), 14.l7E. Amination.t The reactionof the di butanoicacid,with di-t-butylazodicarbor 3 in high diastereomericexcess.The san

8l7o I NH2OH,HCI A ovaallj

(CH,)"C.H.

CuHr-..2N\

i l l \/

(l

t " " '

?^9

| cn.Mo

|

-

BocN=NBc

es'tc

o' I

cHa

I C.H,

Bc.

7

Q At leastone aryl groupin the enoneis essential.The reactionprovidesthe skeleton of streptonigrinoids(equationI).

H

O

O

H

."gocH3-!g,."4 BG:

I

butanoate(4) provides5 in 58Vochemica tection and hydrogenationof 5 providest

I J. P. Genet, S. Juge, and S. Mallart, Tetratx.

ocH3 ' M. A. Ciufofini (1988). andN. E. Byrne,,/.C.S.Chem.Comm.,1230 Hydroxylamine-O-sulfonicacid, H2NOSO1H. canbe preparedby reactionof c-acetylenic Isothiazoles.r Theseheterocycles acid and then with sodium aldehydesor ketoneswith hydroxylamine-O-sulfonic hydrosulfidein a bufferedaqueoussolution.

(R)-3-Hydroxybutyricacid

of aryl en, i '::nedby cycloaddition compounds 1,5-dicarbonyl pr,':ccted pyridines(2). ft rr. l.-1-disubstituted

H2Noso3H, [l;:;'l

"!.-."

t7l

+Na"Soo

#

A

' F.Lucchesini, (1989). N. Picci,M. Pocci,A. De Munno,andV. Bertini,Heterocycles,29,97

,. C-H,-*zov,oc2H5

a - l l I YI

(R)-3-Hydroxybutyricacid (1), 14,178. Amination.t The reactionof the dioxanone2, derivedfrom (R)-3-hydroxy(14,115-116)providesthe derivative butanoicacid,with di-t-butylazodicarboxylate 3 in high diastereomericexcess.The sameaminationof an alkyl (R)-3-hydroxy-

CuHt I slq" I NH2oH' Hcl A ovsall I

(EHr),C,5H5

ol At o b

C.Hr-...2N\

t

i l l

\<

(EHr)2C6H5

Y - - " '

Y

CHrMO

I CuHt

o

c

N t

| ' - '

=

N

B t

e5qc

o

ocA ot

l l

CH3YO

B*);ffi".

2

7

o

B. T:c. reactionprovidesthe skeleton

H

t i cHYocH,

O

l J:l*'

O

H

l

i

cH|-

O

l ocH,

o

H

O

l l cH}. l**

BocN-NHBoc 5 (647ode)

l

ou

NHt 6

butanoate(4) provides5 in 58Vochemicalyield and in 64Vooptical yield. Deprotectionand hydrogenationof 5 provideso-allothreonine(6) in 50Voyield.

I

I

'J. P.Genet,S.Juge,andS. Mallart,Tetrahedron (1988). Leuers,29,6765

ocH3 I 230(1988).

I E ::rrared byreactionof ct-acetylenic )-..:.ionicacidandthenwith sodium

r I

Iodine. S-Atkylidene-4,5-dihydrofurans.t Reaction of 2-alkenyl 1,3-dicarbonylcom(2). Dehydroiodinpounds(1.)with 12effectscyclizationto iodoalkyldihydrofurans (3), which undergoacid(DBU) of 2 resultsin 5-alkylidene-4,5-dihydrofurans ation (4). catalyzedisomerizationto furans

oc,H.

OC"H.

01

OC"H. / " -

,t%-

ECHCH3

O< CH,

l, translcis = 85:15

O:C/

,,bI,,,jlO : C / \r-../

i

l

/

\

\

CHA.,ACHCH3 I 2 ( 8 5 :1 5 )

-

.

DBU

-

e

)-r

/c '

cuSeFCr,

3 (E,98Vo,fron erythro-2) zo* xro* |

The reactionof IrlAlO3 with alkencs resultin iodo chloridesbut in alkyl iodidc of I, with surfacehydroxyls.This reacoo alumina,but yieldsare higher (30-85%| not occur on silicagel. The reaction of IrlAlO3 with alkl-rrr diiodoalkenesin 82-92Voyield. Yields a stitutedby a carboxylgroup.o I-Iodo-I-alkynes.s These compourx lithium acetylides,but they can alsobe ot l-alkynesin DMF catalyzedby CuI underpl or KzCO:as base).

I R. Antonioletti, F. Bonadies,and A. Scctrn : T. Yamauchi.K. Hattori. K. Nakao. and K r Similar resultshavebeen reportedin a patco { R. M. Pagni,G. W. Kabalka,R. Boothe.K t

D. Gray, S. Larson,and T. Luidhardt.l. Or sT. Jeffery,l.C.S. Chem.Comm.,909(1968

Iodine-Copper(Il) acetate. cis-Diols, The reaction of an alkenc a mixture of products which is hydrolrzc

oc,H. O:C/ \--

diol. In the case of Alcholestene. this rt diol. Yields are drastically lower if propx

lt \

cui\o^cH2cH3 l) 12,C!(OA.b, f,

2)Kolt clrglr

4 AICH(CH)COOH. Theseacids(or the esters)havebeenobtainedby a I,2is effectedmost (c/. n,452). This rearrangement aryl migrationof propiophenones easilywith iodine or ICl. in trimethyl orthoformate.2s

o tl

p-RCTH.CCHTCHt

cH3l

R=H R = i-Bu

Reactionswith Iron alumina. A mixture of an areneand iodine when shaken with aluminapreviouslydehydratedat 400'canundergoiodinationat temperatures above110o.The methodis usefulfor reactivearenes.Thusazulenecanbe converted to the 1,3-diiododerivativein quantitativeyield' t72

' C. A. HoriuchiandJ. Y. Satoh.Chem.Irt

Iodine-Hydrogen peroxide. Phenols -->quinones. Oxidation of 1 1 eq. of HrO, (60Vo)and excessiodinc u are generally70-98%. The actualoxi&r

Iodine-Hydrogen peroxide

comn ,.r l-alkenyl1,3-dicarbonyl I l.rrhr drofurans(2). Dehydroiodinr,i:,'iurans(3),whichundergoacid-

-oCrH,

O:C! qr,

:1; +rq

/C''

h cHi\sFCr,

3 (E, 987o,from erythro-2) ,o* | xro' I

o:ct

/

.oc'Ht

r\

The reactionof IrlAlO, with alkeneseven in the presenceof NaCl does not resultin iodo chloridesbut in alkyl iodides.EvidentlyHI is generatedby reaction of I, with surfacehydroxyls.This reactioncan even take placewith nonactivated alumina,but yieldsare higher (30-85%) with activatedALO:. This reactiondoes not occur on silicagel. The reaction of IrlAlO3 with alkynesfurnishesa practicalroute to (E)-vicdiiodoalkenesin 82-92% yield. Yields are lower (25-50Vo)if the alkyne is substitutedby a carboxylgroup.o I-Iodo-1-alkynes.s Thesecompoundsare usuallypreparedby iodination of lithium acetylides,but they can alsobe obtainedin70-90Vo yield by iodinationof (BuoNCl,NazCO., conditigns l-alkynesin DMF catalyzed by CuI underphase-transfer or KrCO3as base). rR. Antonioletti, (1988). Letters,29,4987 F. Bonadies, andA. Scetlri,Tetrahedron :T. Yamauchi, (1988). K. Hattori,K. Nakao,andK. Tamaki ,1. Org..53,4858 r Similarresults (1986)]. havebeenreported in a patent[C..4.,105,6321p 'R. M. Pagni, C. Dial, R. Conaway, K. Gaetano, L. J. Stewart, R. Boothe, G. W. Kabalka, J. Org.,53,4477(1988). D. Gray,S. Larson, andT. Luidhardt, 5T.Jefery,J.C.S.Chem.Comm.,909 (1988). Iodine-Copper(Il) acetate. cis-Diols. The reactionof an alkenewith Ir and Cu(OAc), in HOAc provides a mixture of productswhich is hydrolyzedby KOH in aqueousCH,OH to a crsthis reactionresultsin the more hinderedcisdiol. In the caseof A2-cholestene, diol. Yields are drasticallylower if propionicacid replacesaceticacid.

cHlo^cH2cH3 4

1-\ \-/

e.:.r\ | havebeenobtainedbY a l'2is effectedmoct - T n:. rearrangement f,lT.:lc.:

'oH ll',n;ii3fii}#?6", n *" \,/'...oH

HO

'

l-

HO CH"

I

p-RC.H.CHCOOCHT+ CHrl 669o 987o

E (r! .tnareneandiodinewhenshakeo n u:lJ!-rgoiodinationat temperaturct ue: c. . Thusazulenecanbe converted r.J

173

-:\./ H

(2p,3p-diol) (1988). C. A. HoriuchiandJ. Y. Satoh.Chem.Letters,1209 lodine-Hydrogen peroxide. Phenols --+ quinones. Oxidation of phenolsto quinonescan be effectedwith I eq. of HrO, (607o)and excessiodine in methanolat room temperature.Yields rre generally70-98Vo.The actualoxidant is probablyiodine and the function of

n4

lodobenzenedichloride[Phenyliodine(Ilf dichloride]

phenols HzOzis to reoxidizethe HI formedto 12.The oxidationof 2,6-disubstituted This oxidation in this oxidation. iodine replaces proceedsin high yield if bromine intermediate,which can be isoprobablyinvolvesa 4,4-dibromocyclohexadienone lated from oxidationof 2,6-di+-butylphenol.

( \ :

,I. I F. Minisci,A. Citterio,E. Vismara,F. Fontana, andM. Correales' S. DeBernardinis, (1'989). Org.,54,728

oao

r

Iodine-Mercury(Il) oxide. Ring expansionof cycloalkanones.r The hypoiodite reactioncan also be used lactols(cf., for a four-atomring expansionof cyclicketonesvia the corresponding 13.150).

I R. BatraandR. Breslor

Iodosobenzenetetrefirq dec., is obtainedby reac It convertsenol silvl r

q

I Bu3SnH' e2% hv IATBN,

o

C.ltl

In contrast,a reagentd -20', and formulateda I H. Suginome (1988)' Chem.Letters,245 andS. Yamada, Iodobenzenedichloride[Phenyliodine(Ill) dichloride]' CuH,ICl' (1)' Remotechlorination (6, 298-300). Breslow has extendedhis remote functionalizationof steroidsto a doublefunctionalizationat Ceand C'7of cholestanol. acid,when Thusthe ester(2) of cholestanol,preparedfrom a p-iodophenylnicotinic of treatedwith 1 (1.2 equiv.)is chlorinatedselectivelyat Cq;chlorination the same esterwith 3 equiv.of C.HTICLresultsin chlorinationat C, and at C,7in quantitative yield. The para-iodogroup of the ester plays an important role in this remote chlorination.

s a l t4 . 2

V. V. Zhdankin,R. Tykrr Tetrahedron Letters,X). 3 : Idem,ibid.,29,3703(19&

Iodosylbenzene, C.H.IO Amines --> Imincs.t aminesactivatedby an a the yield are increasedb this respectiodosylbenz

Iodosylbenzene

tit.l of 2,6-disubstitutedphenols D\r.r.1tron rn this oxidation. This oxidation drr: which can be isorntermediate, n('r:

,:

.I. i)rBernardinis,and M. Correales,

g li',3,rroditereactioncan also be used D<\ \ r.r the corresponding lactols (cf.,

2 ' Y= r l I R. BatraandR. Breslow,Tetrahedron (1989). Letters,30,535 Iodosobenzene tetrafluoroborate,(C6H5i)rO28F.,- (L). This yellowsalt, m.p. 160" dec.,is obtainedby reactionof C.H,I(OAc),with HBF, (75% yield.) It convertsenol silyl ethers(2) into 1,4-diketones (3).'

Hg() -l:

,---------+ \J%

C.H'C:CH, -l+ I osi(cH3)3

I Bu3snH, 9270lArBN, nv

o

o il

o tl

c6H5ccH2cH2cc6H5 3

7

*I

c6H5ro.HBF4

c6H5icHrcoc6H5BF44 In contrast,a reagentobtained by reactionof C.H,IO with HBF.' in CHrCl, at -20', and formulatedas C.H.IO.HBF,, converts2 into an unstableiodonium 1:

.\\ r

lchkrridel, C.H'IClr (1). rr. .r has extended his remote funcE..- .::r()nat C, and Cr-,of cholestanol. (t::' .: j)-r()dophenylnicotinicacid, when tr;::: r .\ at C,; chlorination of the same rr:..::i(rnat Coand at C1,in quantitative [r. .:n important role in this remote

salt4.2 rV. V. Zhdankin, R. Tykwinski, R. Caple,B. Berglund, A. S. Koz'min, andN.S.Zefirov, Tetrahedron Letters, 29,3717(1988). : Idem,ibid.,29,3703 (1988). Iodosylbenzene, CoH.IO. Amines"->Imines.t This reagentcan effect dehydrogenationof secondary aminesactivatedby an aryl group or an c,B-doublebond to imines.The rate and the yield are increasedby addition of ClrRu[P(CuH.)1.and molecularsieves.In this respectiodosylbenzene differsfrom t-butyl hydroperoxide,which also effects

176

lodosylbenzene

but only in the presenceof the Ru catalyst(13' 54)' Primary this dehydrogenation, in situ to the amines ur" ulro oxidized by C6H5IO,but the imines are hydrolyzed carbonyl precursor' Ru(tr), CeHsIO,

C.HTCH:CHCH:NCoHs

C.HTCH:CHCH2NHC6H5 #'

high yield. Thesesalts,in contrastto un' phileswith the iodine (III) substituentas

Alkeny liodonium tetrafluorobomta (l saltscan undergoeliminationof iodober goes 1,5-C-H insertion (equationI). Tl

oxidationofamines.2AminescanbeoxidizedbyCoH,Iotonitriles,ketones, and lactamsas indicated'

o CH,

(r)

2C6H5IO,

n-CsHrrC-N

n-CrH,,CH'NH, #

l) Phro, BF3.O(C2lt2 2) NaBF. + E04

SnBu,

c6H5lo

o

,

4e% \,/

\-/

\J

cuHrr,o, 4s% A

n

(-,)

BF

\*Ao

i

l

H

possiblyby deIt can effect oxidativedecarboxylationof cyclic amino acids, hydrogenationto an imine. H

H

oor*>"'too" r.*uooY*Yo n"--

\J

\J

rearrangementof a p-alkyl group to pm 2. This c-eliminationof alkenyliodonium CH, c6H5l

o

BF4-

Vinyliodoniumsalts.'Reactionofvinylsilanes(2)withiodosylbenzenecat(3) in generally alyzedby BFr etherateresultsin vinyliodoniumtetrafluoroborates BF3'O(C2H5)2 C5'H5lO' /

(CH3)3c< \__J

\\

)-si1cH'),

--G-cHrcb.0'

2

rather than a carbenoid,sincethe (EF baseproduceessentiallythe sameprodu (ll)

,.",,,.fl-T:1. * tcH,i,c$No' 3 r:-eo*Jnzcuu

,a"rrraO*

CrH,r, ,Bu

Koc(cH3h

i\l*cuH, l o

BFo(E)-3 (z)-3

63% 65%

a-Oxo tiflates.s Reaction of tnmel (Tl methylsilyltrifluoromethanesulfonate :riflatesin 55-75Voyield.

Iodosylbenzene

D.< .ri the Ru catalyst(13, 54). Primary bc :rrrnesare hydrolyzedin situ to the

I'

C.H.CH:CHCH:NCeHs

177

high yield. Thesesalts,in contrastto vinylsilanes,reactvery readily with nucleophileswith the iodine (III) substituentas the leavinggroup. Alkenyliodonium tetra;fluoroborates (r4, 10-11). on treatmentwith basethese saltscan undergoeliminationof iodobenzeneto generatea carbenoidthat undergoes 1,5-C-H insertion (equationI). This eliminationcan competewith a 1,2-

or:irzedby C.HTIOto nitriles,ketones,

o

0)o\

p !

4-CjHuC-N

cH, " 1H1b,.,",, 2) NaBFd 8U7o

I

SnBu,

o p

tl

A.A'-cH, \ / ll F I

\J

--\

BF4-

t*Ao

lt-l-C6H5

Koc(cHlh --7-"

CH,

H

c: ,r;hc amino acids,possiblyby de-

6u:n

H N F) tr

\

rearrangementof a B-alkyl group to producean alkyne as in the caseof the salt 2. This ct-eliminationof alkenyliodoniumsaltsis believedto involvea free carbene

n

/

\___J

lpr . .,rn€S(2) with iodosylbenzene catDr--- :etrafluoroborates(3) in generally

:

Iti.

ilrr. -=rcH,r,c$No,

1

| VaJt,, Il o

.L6n5r ri)' BFo-

cH'\^ N(crH<)r 67%

o \

+ cH3c-c(cH2)3Cc6Hr3 'C ,r"o"r3 67:33 J

2 rather than a carbenoid,sincethe (E)- and (Z)-isomersof 3 on treatmentwith baseproduceessentiallythe sameproducts.a (ll)

CrH,r. ,Bu

Koc(cHt3

Ar.CtHn

rt-l'c6H5

\ i l

Y CH;

BF4(E)-3 (Z)-3

63Vo 659o

-

A,-Bu

\ l l C,Hi, 49:51 51:49

a-oxo fiiflates.s Reactionof trimethylsilylenol etherswith c6H,Io and trimethylsilyltrifluoromethanesulfonate (TMSor0 in cHrcL at - 7g' affordsa-oxo triffatesin 55-75Voyield.

17E

2,3-Isopropylftlen+'2.}l

Iron3+-Montmorillonite (Fe'Mont)

o tl

OTMS

ry'"

---:-) ATCCHOTf ArC:CHCH3 + C6H5IO+ TMSOTf

+ CHrCH:C|

I

CH, I P. Miiller and D. M. Gilabert, Tetrahedron,44'7171(1988)' ' R. M. Moriarty, R. K. Vaid, M' P' Duncan, M' Ochiai' M' Inenaga, and Y. Nagao' TetrahedronLetters, 29, 6913'6917(1988)' 3 M. Ochiai, K. Sumi, Y. Takaoka' M' Kunishima,Y' Nagao' M. Shiro, and E. Fujita' Tetrahedron,44, 4095 (1988)' a M. Ochiai, Y. Takaoka,and Y. Nagao,Am' Soc',110,6565(1988)' Letters,30, 5 R. M. Moriarty, W. R. Epa, R. Pinmasta,and A. K. Awasthi, Tetrahed'ron

AA,


/osi(cH

-oqE

-osi(cH +cH'cH:ci*n

667(r98e). N-Iodosuccinimide(NIS). provides Iodoacetalization. Reactionof a vinyl ether with NIS and an alcohol plQvide to base an iodoacetal,whichundergoeseliminationof HI whentreatedwith of unsymmetrical a keteneacetal.This sequenceis particularlyusefulfor synthesis keteneacetals.

1""

MS (cH.).COH

CTHTOCH:CII, -?

CH

KOC(CH3)3 THF.25'

/ \oc1cH,),

c2H5o

51qo

CH"

il-

C \oc(cHr), c2H5o/

I D. S. Middletonand N. S, Simpkins,Syn'Comm',19' 2l (1989)'

Ion-exchangeresins. l'5' an ionCleavige of hydrazones,oximes,and semicarbazones' Amberlyst of exchange for reagent superior is a groups, exchangeresin with sulfonic acid 85-95Vo are Yields acetone. with compounds nitrogeieous derivativesof carbonyl with reactionsthat proceedat room temperature'r

I M. Kawai,M. Onaka,andY. Izumi,Butl C r M. Onaka,R. Ohno,andY. Izumi,Tarofu

F,3-Isopropylideue-2,3-dihydroxy-1,$li1 273;5, 360-36r;9, 259-260; 13, 153. Asymmetric hydrogenation of iuca pareda new bisphosphine ligand(2). nhi metric hydrogenationof itaconicacidstric in four stepsfrom 4-bromo-2,6-dimethv

'Jx:r

Esterification.2Acidsareesterifiedinhighyieldwhendissolvedinmethanol hourswith yields containini Amberlyst 15. The reactionis effectedat 25" in 4-14 epimerization' without >80Vo.Chiral acidsare esterified I R. BalliniandM. Petrini,l.C.S' PerkinI, 2563(1988)' ' M. Petrini,R. Ballini,E. Marcantoni, andG' Rosini'Syn'Comm'' lE' 847(1988)' (Al-Mont)' Iron3*-Montmorillonite (Fe-Mont) or Aluminum3*'Montmorillonite Preparation.' N.Silyldihydropyridines.2Pyridinessubstitutedatthemeta-positionbyan the presenceof Feelectron-withdrawinggroup react with silyl ketene acetalsin orAl.Mont(1)togivea4-substitutedN-silyl-l,4-dihydropyridineinhighyield.

(4R' 5R)'(-F:

QH, ll

HOOCv,,,\.cooH

q Rr'.

=

tu"t\

"ooc-4coo"

'ta

2,3-Isopropytidene-2,3-dihydroxy-1,4-bis(diphenylphosphine)butane

o tl

Ol: --------rArCCHOTf

I

CH, rt_

rl

.

q:b

l;hrai.

I

si(cH3)3

).

M. Inenaga, and Y. Nagao,

\agao, M. Shiro, and E. Fujita,

ta \

*-r,1a",y,

. u0 6,565(1988). A K Awasthi, TetrahedronLetters,fi,

thcrrrrlh NIS andan alcoholprovides ll I 'r hen treatedwith baseto provide trs: .;. f r)r synthesisof unsymmetrical

CH

\ L cH3b - !E

. r(o r_+ -a

ft.

ll

> /

c2Hsot

\ -oclcHr),

r le il (19U9).

*arln:ones. Amberlyst15, an ionr ..:rnor reagentfor exchangeof p. u irh acetone.Yields are 85-95Vo

cooc2H5 I M. Kawai,M. Onaka,andy. Izumi,Bull. Chem.Soc.Japan,6l,1237(19gg). r M. Onaka,R. Ohno,andy. Izumi,Tetrahedron :l47(lgg9\. Letters,30, &'3-Isopropylidene'2,3-dihydroxy-r.,4-bis(diphenyrphosphine)butane (DIop), 4, 273;5, 360-361; 9, 259-260:13. 153. Asymmetric hydrogenation of itaconic acids,t Japanesechemistshave prepareda new bisphosphine ligand (2), which is more efficientthan DIop for asymmetrichydrogenationof itaconicacidswhencomplexedwith rhodium.It is available in four stepsfrom 4-bromo-2,6-dimethylphenol.

f"' \ 4ftocu,\ <\z( I cH, /2

'Jx:r, -Qa

cH.

lu: i

\

ish ' rcld when dissolvedin methanol r:(J r! 15"in 4-14 hourswith yields irncnz.ttton. ll -..

r:: irmr'

\ \ , 1 .C o m m . , l E , 8 4( 7 1988).

\,t'-ocH, 'a",

/ /

(4R,5R)-(+)-2

9H, Yz, 9H, Hooc\.,.4. "ooa cooH r o0%gll- -A aoon S, 86-917oee

-Montmorillonite (Al-Mont).

tu"') x:r:ured at the meta-positionby an lercnc acetalsin the presenceof Fein high yield. Fi --Jrh1'dropyridine

\

HooCv,'\CooH

aunr\

,;* .

"oo"-Acoon S , 9 6 V ae e

2,3-Isopropylidene-2,3-dihydroxy'1,4-bis(diphenylphosphine)bulane

of 2 in respectto DIOP is consideredto derive The enhancedenantioselectivity from the para-methoxygroup and methyl groups' DIOP analogs.2 Japanesechemistshave prepared a symmetricalDIoP (3) in which the phosphine is substituted by a para-dimethylaminogroup and two unsymmetricalDIOPS (4 and 5), and have examinedthe effect on asymmetric

H

H

an,Vo n

cgi

fl

cHr. '\./ro -l^| P[c.HnN(CH,)r-p l,

to-h:z

n

P[CuHoN(cH,)'-p CHi I'

P[CoHoN(cHr)r-p l, ' " ' l \6-[.,PAr, H

H 3, ao+ 23"

(S)-Lacticacid,

HOOC. -H HO-'.CH,

AsymmetricDiels-Alder reaction.l T olan-4-one(3), preparedfrom pivaldehl'de cyclopentadieneat25" to form only two of

4, Ar = CoHs,oro-1.70o 5, Ar = CeHoCHrn, c"= 8.4o

Rh* hydrogenationof rhodium complexesformed from [Rh(coD)cl]r or from reactivity greater chemical show 5 4, and from 3, prepared 1-Ony.nE.-. Catalysts in than the catalystpreparedfrom DIOP and somewhathigherenantioselectivity electron-rich an Therefore, itaconate. dimethyl hydrogenationof itaconicacid and phosphinehas someeffecton the rate and enantioselectivity' (1989)' I T. Morimoto,M. Chiba,andK. Achiwa, Tetrahedron Letters,30,735 (1988)' 2T. Morimoto, 4755 ibid.,29' M. Chiba,andK. Achiwa ,

(SFl.

O

.CH.

)a (cH3)3ccHo + (S)-1

d1"b -{ : c(cH3)3

tt",

(2S,5S)-2(62%&l

(2S).3+O+A

(lR,2& {l

both formed by 96Voface selectivity for ti selectivity.A reactioncatalyzedby CllTil (15,2R,4S)-4, in the rau and (1S,2S,4S)-4 a Lewis-acidcatalystlowers the overall I creases rr-faceselectivity.SimilarresulsoH

andG. Maas,Ber.,lZl J. Mattay,J. Mertes,

OH

t

(S)-Lacticaldehyde, HCOCHCH3(f). Pn Optically active P-lactams.' The rer with the optically activesilylimine2, prep ricallyactiveB-lactam3. The opticalpuritl by conversionto the antibiotic carbapene

tliF)bulsne

t r,' DIOP is consideredto derive lcr.1rcd a sYmmetrical DIOP (3) u-JrnrethylaminogrouP and two u::r:'c,j the effect on asYmmetric t{ t' ---/'

(

| !

t, -\,' , H

(S)-Lac'ticacid, -PlcnH4N(cHr)2-p 12 PAr'

cr"-1.70" \: - CoHs' oo= 8.4" \: = CuHoCHr-m,

r.'nr IRh(COD)CI], or from Rh. ! .[,rrr greater chemical reactivity rs h.rt higher enantioselectivity in cr.,:.. Therefore, an electron-rich

HOOC- -H uO-.Cn,

(S)-1.

AsymmetricDiels-Alder reaction.t The (2S)-2-r-butyl-5-methylene-1,3-dioxolan-4-one(3), preparedfrom pivaldehydeand (S)-(+)-lactic acid (1), reactswith cyclopentadiene at 25" to form only two of the four possibleDiels-Alder adducts,

on

it"'

J \ "" ' oaz'o (cH3)3ccHo (S)-r +

o\]'crL l) NBs(eB%)

J

oYo iiiirc-'riJico*r '

c(cH3)3 (2s,5S)-2(62Vo de)

\^

c(cH3)3 (2S)-3

t t r . ' . (i c c t i v i t y . D4 , :;:cr\. 30, 735(1989). a-<: le$t{}.

(2S)-3 +O + ffi*.",,,,u1-4or (lR,2R,4R)-4

O4oZ"'C(CH,), (1S,2R,45)-4

both formed by 96Voface selectivityfor the methylenegroup and with 96Voexoselectivity.A reactioncatalyzedby Cl,Ti(O-/-Pr), at -20" gives (1R,2R,4R)-4, (1S,2R,4S)-4, and (1S,2S,4S)-4 in the ratio 59:1:40in 62Vochemicalyield. Thus a Lewis-acidcatalystlowers the overall yield, increasesexo-selectivity,but decreases zr-faceselectivity.Similarresultsobtainin reactionscatalyzedby CrH5AlCl2. 'J. Mattay,J. Mertes, andG. Maas,Ber.,ltil,327(1989).

?"

(S)-Lacticaldehyde, HCOCHCH3(1). Preparation.' Optically active S-lactams.2 The reaction of the enolateof t-butyl butanoate with the optically activesilylimine2, preparedfrom silylated1, providesthe optically activeB-lactam3. The opticalpurity and configurationof 3 was established by conversionto the antibioticcarbapenem(+)-PS-5 (4).

t'b||tyl

L-r-L€ucine,

ester

rl cflcH{(e11

9t*, I

LNtsicHibt2

)

i"",

i

l

t 1or*r czHs...a_AcHr

2) HF cHrcN (e?%)

C(CH3)3

OH

O{'Bu

,

(cHr)rsi/ ,'

crL4( ll

\-)

?-t{H

"

O_r

Nffi:") (cH3)3cooc

3

f

c(cH,),

1,.',,,.1j,^ 6...| .)-.-) |

cr"r..._Lr | | ,!s1cH;5nac ^2-N-4 U \

L

COOH (+)-Ps-5(4)

"€;/-\"

z

.

rM.Hirama,I.Nishizaki,T.Shigemoto,andS.I'Ito'.I'C'S'Chem'comm''393(1986)' Am' Soc'' 110'6879 2G. Cainelli,M. panunzro, D. G[comini,G' Martello,andG' Spunta, (1988). Lead(II) bromide/Aluminum,PbBr'/Al (1)' AdditionofCXntoCHo.|Thisbimetallicsystemeffectsaddition'ofCXoto aldehydesinDMFat25'in>T5Voyield'PbBr2canbereplacedbyPbClz'Pb'or SnCLwithonlyslightlyloweryields.Thesystemalsoeffectsal,2-eliminationfrom

+cx.ffi RCHo X=Cl,Br

OH I RcHCX3

with a aldimine2, preparedfrom 1' reacts an ep iodide to form the aldehyde3 and middlt product (3) was used to furnish the andI ' K. Tomioka,F. Masumi,T' Yamashita'

l{-Lithio'N,N',N' -trimethylethylenedid

I I, HCl,

lHro,50-60' OH

I

t This reagentis prepared by sonication THF' enediamineand lithium in 1' ofiho'Hydroxylation of AttHO't d provides Li) rhen with BuLi (or BuCl,

RCH:CXzor RCHCXTH (lo-50%) 1o-nw

theproductstoaffordl,l-dihaloalkenesand/oraproductofreductionofonehalo group.

l-

oLi

3."o*Lo

(1989). lH. Tanaka,S. Yamashita, M. Yamanoue,and S. Torii, I. org.,54,444

(1)' r+-Leucineis availr-f-Leucine,r-butylester,(cH,)rccH(NHr)cooc(cH3)3 ablefrom Aldrich (exPensive)' of ( + doublealkylationof a,p'enaldimines' A synthesis )-ivalin' Asymmetric anantileukemicsesquiterpene(4),isbasedonthisstereoselectivereaction'The

N-Lithio-N,N'.N' -trinethylethylenediamine

OH

JiBu

I ca - ,_. uzns...r_rACHr 6t%) r-------------l :-+

C(CH3L

/ t \ffi\^,) ./<" (cH3)3cooc

^_

cH2=ccH,M8Br

\

rl fo'

d*

___lyg:

"*?hi)

3

[.*uffF{+

fl.,.\FLAc

"N

""/

\n,

3 (95Voee)

lo b

1 ( S. Chem.Comm.,393(1986). 6879 rnd G. Spunta,Am. Soc.,110, H

CH2

c r\.:em effectsadditionof cXo to ; c"r be replacedby PbClr, Pb, or from ) 3.'\ effectsa 1,2-elimination

4

aldimine2, preparedfrom 1, reactswith a Grignardreagentand then with methyl iodide to form the aldehyde3 and an epimer at C, as the major products.The product(3) was usedto furnish the middle ring of ( + )-ivalin (4). (1989). K. Tomioka, F. Masumi, T. Yamashita, andK. Koga,Tetrahedron,45,643 -Li (CH3)rN(CHr)rNl (1) N-Lithio-N,N',N'-trimethylethylenediamine, -CH,

x, Itl-

p!, $

OH

I

This reagentis preparedby sonicationof a mixture of N,N,N'-trimethylethylenediamineand lithium in THF. ortho-Hydrorylation of Ar{HO.t The reactionof an aldehyde(2) with 1 and then with BuLi (or BuCl, Li) providesthe adduct3, which is oxidizedby O, or

= C \ : o r RCHCX, n4

( l0-507o)

a lr\)duct of reductionof one halo

f

oI-i

z\(cHo, l<>^N.'(cH,),N(cH,),,u.,.,.,,)),i . l l - . " - l l CH, l l ' l - - - , \,/ LV

or'.: J Org., 54,444(1989). )O('rCH,)3(1). l-r-Leucineis availof ( + )-ivalin, Ynincs. A synthesis reaction.The I rhr! stereoselective

ot-i

I a>Ao,(cH2)2N(cH,,, | *,0 41cno

\A'

Jn,

-lt-\Ao"

tl

Lithium aluminum hydride-Bis(cyclopentedienyl)nickel

cHo

CHO

Z\A

r^i.\roH

.< 2"7A \

\

)

2

)

yields obtain if 3 is Mooph at 00 to the ortho-hydroxylatedaldehyde (4). Higher 30vo Hzor' with oxidation by convertedto the tributylboronic ester followed J'C'S Chem'Comm''1350(1988)' rJ. Einhorn, J.-L.Luche,andP.Demerseman' Lithium. Reactionwithmethylenecyclopropane.|Lithiumpowderreactswithmethyl(2) asthe only product' in etherat 25otoform},4-dilithio-1-butene enecyclopropane to a methylene-1,3precursor is a This dianion is stable at 25'for 27 days;it dicarboxylicacid.

pyridyl)(1,5-cyclooctadiene)nickel. LiAIH propertiesof L suggestthat the activespo

' M . - C .C h a nK , . - M .C h e n gK, . M . H o . C . T Luh,J. Org.,53,4466(1988). r J. J. Eisch,L. E. Hallenbeck, andK. l. Han

Lithium aluminum hydride-Lithium iofl syn-l,3-Diols.r LiAlH4 alone shors hydroxyketones,but additionof Lil prorr of B-alkoxyketonesand B-alkoxy-p'-ht..

fH' c\-l-T, g o...A/--a(cH,),osiR,

4",7-.

CH. / '

;

oH

g

L

o\-A=A=4(cH2)20si

cH,
z svo |co2

COOH I

cn"Alcoon rA. Maercker andK.-D. Klein,AngewChem'Int' Ed''28' 83(1989)'

Y. Mori, M. Kuhara,A. Takeuchi, andM. ! Y. Mori, A. Takeuchi, H. Kageyama. andV

Lithium N-benzyltrimethylsilylamide ( tS Cyclization of 2,6-octadienoic cstctt. rion of this reaction to these dienoic e, (4). n (3) and cyclohexanes cvclopentanes

-,,1-,COOCrH5 I

t Lithiumaluminumhydride-Bis(cyclopentadienyl)nickel(l). desulfurizationof thiols' Desulfurization (13, 153-15-9).' In addition to (1:1) can serveas a hydrogenthioethers,sulfoxides,and sulfones,CprNi-LiAlHa enonesto ketones,but in ation catalystfor reductionof alkenes;it also reduces lowyield.Ingeneral,itissimilarinreactivitytoRaneynickelandto(2,2,-bi.

':r"a:t ^'(1.,] **.,, f CprNiAlHrLi'THF

R,

\,

-

r1Lsr"nr 2) HoA.

*

\cooa,n, I

cooc2H5 + J er* L

LithiumN-benzyltrimethylsilylanide(LSA)

cHo \=,oH r/

./ l{rgheryieldsobtainif 3 is d.jrr{)nwith 30VoH2O2.

pyridyl)(1,5-cyclooctadiene)nickel, LiAlH,(THF)".C10HsN2.Ni.2 The spectroscopic propertiesof L suggestthat the activespecieshas a bridgedstructure. I M.-C.Chan,K.-M.Cheng, K. M. Ho, C. T. Ng,T. M. Yam,B. S. L. Wang,andT.-Y. Luh,J. Org.,53,4466(1988). rJ. J. Eisch,L. E. Hallenbeck, (1986). andK. I. Han,Am. Soc.,10E,7763 Lithium aluminum hydride-Lithium iodide. in reductionof Bsyn-l,3-Diols.t LiAlH4 alone showsno stereoselectivity hydroxyketones,but additionof LiI providesa syn-selective reagentfor reduction of B-alkoxyketonesand B-alkoxy-B'-hydroxy ketones.

n | , r n t n . , 1 3 (5109 8 8 ) '

t"'"d-Ao-(cH2)2osiR3

LiArH4. Lrr t"rtr-Tr

+;5

L3'\\der reactswith methylu:src (2) astheonlYProduct. !...tr\(rrto a methylene-l,3-

CH. ' / OH

d..'AAz--(cH2)2osiR3 -- 96:4 synlanti

CH"

CH"

,n,+n:

j

lEs

oH

o

dv\-A

oH oH Lir cH,A LiArH,, ."\.4=^v4'(cH2)2o i \ l l

%% (cH2),osiR,

SiRl

synlanti= 95:.5 Y. Mori,M. Kuhara,A. Takeuchi, (1988); andM. Suzuki,Tetrahedron Letters,29,5419 Y. Mori,A. Takeuchi, H. Kageyama, (1988). andM. Suzuki , ibid.,29,5423

tcrtoH

Lithium N-benzyltrimethylsilyl amide (LSA), (CH.).SiNLiBzl. Cyclizationof 2,6-octadienoicesters.t LSA adds 1,4 to crotonoates.Exten.ion of this reaction to these dienoic esters(l and 2) resultsin cyclizationto (3) and cyclohexanes cvclopentanes (4), respectively. HNBzI

I .: r1989).

---;;-q,^,^^^

./'V,COOCTH, llrrA,rHF,-?r&COrCrHs lel (l). t.' Jesulfurizationof thiols, I . ' can serveas a hydrogenF. 3nonesto ketones,but in RJr.\ nickeland to (2,2'-bi'

(

il -coocrH, I

^'"coot'"'

l,_.

.i.'

cH2cooc2H5 3

-----.--r====?+ cooc2Hj s3% L--____-_-_LCH2COOCTH5

\

1.oo..".

4

1E6

Lithiumborohydrid+Europium(Ill)chloride

This tandem conjugateaddition followed by B-eliminationwas used to effect (7) from (5) via 6. synthesisof dihydronepatalactone CH, co2c2H5 r) LsA ,r="zCooc'Ht 2)cH,r,rqco,r( |

__-

\--N/,cooc,H5 H

cooc2H5 5

l CH,

' Y. Kishi,Chemica Scripta,27,573 (t9$7l.

Lithium r-butylhydroperoxide,(CH,).COC by reactionof BuLi or CHrLi with l-bunl Epoxidation of enones,enals,o.,F-u substratesis generally efiected with alkali effectedwith this new reagentwith high s H

6 ('14:26)

RI

Lithium borohydride-Chlorotrimethylsilane(1 : 2) Reductions.r The reactivity of LiBHo (or NaBHo) in THF is markedly enhancedby ClSi(CH)3. The resultingreagentreducesaminoacidsto opticallypure aminoalcohols,and amidesto amines.The activeagentis believedto be a complex of BH. and THF. The combinationof these two reagentsalso forms LiCl and

,

tz-ot

H

\_,/

E

*'nsorc.", o i

l

r

H

C"H,-S< t -:t ll >_c.H.:_s rsN rf

(cH3)3siH. NTLI r.rr 12 NaBH4

J ' \666*:

R'/

(1989)' rT. Uyehara, Chem'Comm',113 N. Shida,andY. Yamamoto,,I.C.S.

lJI{,

H

\

(s)-(+)

:

(cH3)rcHcHco2H crsilcjr3h > (cE)rcHcHcH2oH

O. Meth-Cohn, C. Moore,andH. C. Taljaer C6H5CONH2

;;+

C6H5CH2NH2

ArCH=CHNO, G

ACH2CH2NHz

rA. Giannis AngewChem.lnt. Ed.'28'218(1989)' andK. Sandhoff, Lithiurn borohydride-Europium(Ill) chloride. Enantioselective reduction o! an a,p-enone.r One of the final steps in a synthesisof palytoxin, a toxin of marine soft coralscontaining115carbon atoms and 60 chiral centers,involves,in additionto the usualdeprotections,enantioselective reductionof an enone to an allylic alcohol.A mixture (1:1) is obtained with borohydrides,but lithium borohydridecombinedwith EuCl: providesan 8: I

Lithium cyclohexylisopropylamide(LCI). Thioxanthen-9-ones. This base is sq of thiosalicylamides (1) and for genenion rreatmentof l" and a benzyneprecursor(!

cocH3 SH l

B

r

mixture, with the desiredisomerbeingfavored.

cH, t "

t"'-1A11c*!""5f OH

o

cH'

resultsin thioxanthen-9-one 2 in yields a Jrmethoxy-substituted derivativesof 2 can l !\nthesiscan be appliedto synthesisof u

ll. Watanabe, M. Date,M. Tsukazaki. and! r 1989).

Lithiumcyclohexylisopropylemide(LCI) lE7

t rq:.: :\ p-eliminationwas used to effect ria6.

16. !

Lithium t-butylhydroperoxide,(CH3)3COOLi(1). The reagentis generatedln sl/r.r by reactionof BuLi or CHrLi with r-butylhydroperoxide. Epoxidation of enones,enals, a,P-ansaturated esterc.r Epoxidation of these substratesis generallyeffectedwith alkalinehydrogenperoxide,but can also be effectedwith this new reagentwith high stereoselectivity.

- )oc,H.

v'

-COOC'H.

!/

Ii

' Y. Kishi,Chemica Scripta,2T, 573(1987).

-H

6

-:

36)

\ : 1 \aOO*z

Rt/ ,

( i t e m .C o m m . , 1 1 3( 1 9 8 9 ) '

bae

.:l) 'r \aBH)

in THF is markedlY enBi: acids to optically pure amino :3duces E.-: D.: : - : rr e agent is believed to be a complex and I ::--. tuo reagents also forms LiCl

NH2

f:-;

o

A R''

tcooR'

#lAl,.r,, -><-,.0", t'"';lf f , H l;# "'"' 3 t r.lFot'"' >coH' (s)-(-).

(S) -(+)

:

f-:

t, tz-oo*

cH3)rcHcHCH2oH O. Meth-Cohn, C. Moore,andH. C. Taljaard, J.C.S.Perkin1,2663(1988).

16l: \t{.'\1. :i CH.NH2 7.

aJ .2E' 218(1989)

Ionde. a.g-cnone} One of the final steps in a atornt rrc - li corals containing 115 carbon enantioscdeprotections, :o the usual tr: rlr :- :icohol. A mixture (1 :i) is obtained d::c ;ombined with EuCl3 provides an 8:l 3 :;r.'red. CH" t '

t',anr-rr.rz\.ACHr I ' oH 0u ( 8 :l )

Lithium cyclohexylisopropylamide(LCI). Thioxanthen-9-ones.This baseis somewhatsuperiorto LDA for lithiation of thiosalicylamides (L) and for genertionof benzynesfrom halobenzenes. Thus ireatmentof 1 and a benzyneprecursor(2 equiv.) and 3 equiv. of the base(LCI)

o

G:"n.Q#G)o Br :csultsin thioxanthen-9-one 2 in yields as high as 98Vo.Various methoxy- and Jrmethoxy-substituted derivativesof 2 can be obtainedby this condensation. This !\nthesiscan be appliedto synthesisof acridonesand xanthen-9-selonones. U. Watanabe, M. Date,M. Tsukazaki, and S. Furukawa, Chem.Pharm.Bull.,37,36 I 989).

lEE

Lithium rliicoProPYlemide

diethylamide' Lithium --of the 16-memberedlacThe key step ln a s'vnthesis Dehydroialogenation' of the dibromo 1,t* ,"i;;iiu" .onoO"t vdrohalogenation (2 equiv')' tone norpyrenophorin(6 LDA ivith L, acid acid 2, obtained from trJri"trutvaropyrunylu."ti

HBr,HoAc, .,/,\. 1mo r I

6s%

2

from I

-cHrcooH

\g,

O.",.oo"

LBt

R

t

2(\

'

l r - l . l l

llltsl. t

I

The coupling of the arylboronic ao< (3)'r directlyto phenanthridines

v,

\Z\Nnsoc I

Br

(HO)rB 3 --| x"cot-our' t raa |

2

I

_40.

Dianions of aldols. The reactron the distal dianion, which can be trappo

o

l\:nA

ll

t'o'G

Ho^^cH, l

s

i

CH,

4 1757(1988)' Brocard' Syn'Comm'' 1E' rL. Maciejewski,M Martin' G' Ricart' and J'

CuHt

t*ilil#::T::ll'I)ui bv a 2'-methylgroup (1), ii"*oiti-"ito"rgo'diiected

amides.substituted diethvr * n"o tithiation; Biphenyr acidsand aryl arylboronic prepared.bvcrossco.u,Plingtf 9-phenanthrols' iithiation to provide

Br

.",-A

*rfir Pd(o)'

I

NR2

+ tal

-+

|

l-=4

\*, -

Y

o-eer"

"on,t"t ll CNR, o-zs" , CH,

18-e8eo

Thesedianionsreact with ketone: vield.a

o

tl

cn,-.Acn. | \OH

"

+ CuH.CtlO

J. Fu, M. J. Sharp,and V. Snieckus.Ira V. J. Sharp,W. Cheng,and V. Snieclu M. A. Siddiquiand V. Snieckus.ibrd--! \'. A. Martin and K. F. Albizate,.I. Or3

Lithium diisopropylemide

Gmemberedlac)n of the dibromo DA (2 equiv.).

The coupling of the arylboronicacid 1 with o-bromobenzaldehydes (2) leads directlyto phenanthridines(3).3

Br R

t t

l

t

t

r

) ....Y'11

|

cooH 3

1E9

A l

,,\-,,."o ll

+

Y\Nrmo.

(HO),B

i l l \2
Pd(o), Na,CO. _-.+ 45-89%

2 I

--- I &cor-DMn Dianions of aldols. The reactionof 2 equiv. of LDA with aldolsresultsin the distal dianion,which can be trappedwith ClSi(CH.)..

.7 o *^--,

"oa

O |l

^

OSi(CH3)3 I

r)2LDA

cH,ISI9I!5 (cHr),siofcH,

CH' I r . 1 7 5 (71 9 8 8 ) .

CH, (cH3)3sio

osi(cH3)3 CuH,

amrdessubstituted onrcacidsand arYl l: Thesedianionsreactwith ketonesto give B,B'-dihydroxy ketonesin 55-95Vo yield.a

Q

LDA, THF oJ25' -8-989o

,

o

""'YAt"' \o,

OH

:tl1* "o1\-!",t, + cuH,cHo CH, ( 1: 1 )

J. Fu, M. J. Sharp,and V. Snieckus,Tetrahedron (19gg) Leuers,29,5459 M. J. Sharp,W. Cheng,and V. Snieckus, ibid., ?5,5093,5097(1987). M. A. Siddiquiand V. Snieckus, ibid.,29, 546309S8) V. A. Martin and K. F. Albizate,l. Org., 53,5986(1988).

190

Lithium naPhthelenide

Lithium diselenide,LLSe, (1). This reagentis preparedconvenientlyby reaction as electroncarrier. of Se(0)with Li in THF at 20'with diphenylacetylene Diselenides. These compoundscan be prepared in satisfactoryyield by reactionof I with alkyl halides,epoxides,or lactonesin THF at 20". I L. SyperandJ. Mtochowski, 44,6119(1988). Tetrahedron, Lithium N-lithiomethyldithiocarbamates(1). The reagentis preparedfrom a secondarymethylamine:

i#gt ArrSi-SiAr, - l l ' 5 w . clcl ,

ArrSi:Stnr, J 3

Ar = C.HTCH(CH3)2-2,4,6

-o \o,

Ar.Si'

rec-Bul-i

l) BuLi

-18+-25" '

2)cs2 > RNHCH3 T"", S:CSLi

5

RNCHTLi(l) S:CSLi

N-Butylaminomethylation The reagent1.,R:Bu, reactswith electrophiles -25. to form an intermediate(a) that is hydrolyzedto a N-alkylbutylamine. at

' H. Watanabe, K. Takeuchi, K. Nakajima.l ( le88).

Lithium tetraalkylcerates,RoCeLi.Thesc of an alkyllithium (4 equiv.) with CeCl. a Alkylolefins. These ceratesconvert I

BuI

* BuNCH,Li

B"NcH,Bl#

BuNHCH,Bu

[ lS:CSLi J

S:CSLi

It l c 4 t ti"' ttt

o + BuoCeLi

/\

CuHr'

D'!tL _ I

C^H. ' tCH3\,/'\.,AcH:

rz* |

| 2) H3o*cx,

93:7

J

CH: BuNHCH2Sic6H5 CH: I H. AhlbrechtandD. Kornetzky, (1988). Synthesis,775 Lithium naphthalenide(1). Disilenes.t Disilenes(3) can be preparedfrom 1,2-dichloro-1,I,2,2-tetrasubstituted disilanes(2) by reactionwith lithium naphthalenide.Most disilenesare unstableto air, but 3 is fairly stable.Surprisingly,it is oxygenatedto give 4, rather (5). than the expected1,3-cyclodisiloxane

the solventof choice,and yieldsand regiosc This reactionwas usedfor synthesisof a s

-+[(cH -:A ll

(l) | cH,/^\,/

c(cH3):

Liahium tetEalkylcerates

i t:j.rred convenientlyby reaction c c : . . J n ea s e l e c t r o nc a r r i e r . rcr.:rcd in satisfactoryyield by ret, ::. rnTHF at 20'. .\\

l!

I

cHt

o r'DME q , er^si-Ji Ar,si-siAr" -l - s o %> Ar"si:SiAr" .l l I 3 cl cl bnet ,

cH(cHJ2

4

Ar = CeHzCH(CH3) 2-2,4,6

r) Ar.sil'\siAr. "

mr:t\ lamine:

- o5

L-

RNCHTLi(r) S:CSLi r I R:Bu. reactswith electroPhiles rJr ,.rzedto a N-alkylbutylamine'

I H. Watanabe, K. Takeuchi, K. Nakajima, Y. Nagai, and M. Goto, Chem. Letters, 7343

( 1e88). Lithium tetraalkylcerates, RaCeLi.Thesereagentsare preparedin situ by reaction -20". of an alkyllithium(4 equiv.)with CeCl3at -78'Alkylolefins. Theseceratesconvertepoxidesinto alkylatedolefins.DME is

r".l= BuNHcH,Bu

o /

P CuHr'

\

+ Bu.CeLi '

cHr:-A.z\cH,

D M E ,- 7 8 r - 4 1 "

Mqo

C^H. t"

+

)

CHr-,,r1rz1,,,CuHt

93:7

E, lNVo I

the solventof choice,and yieldsand regioselectivity are improvedby addedTMEDA. (equation \). Nas of a sesquitetpene \sed tor slnthesis T\ris reaction

\

(r) q\\

eu'-a + t(CH)rc:cHcHPH,lnc


|

CH" tl

rasub' D r-t-,u. r r : r r J f r o m 1 ' 2 - d i c h l o r o - l ' t ' 2 ' 2 - t e tare disilenes Most naphthalenide' I to give4' rather iurr::.ingl).it is oxygenated t:


cH,V

i

l

l

( c(cHJ2

tg2

Lithiuntri'scc'butylborohydride or lithium triethylborohydride.The p (3).'

(1988)' I Y. Ukaji andT. Fujisawa, Letters,29,5165 Tetrahedron Lithiumtetramethylpiperide-Tetramethylethylenediamine(LTMP-TMEDA)' [3,3]sigmatropic canoll neufrsngemenl. Diastereoselective Diastereoselective estercan be effectedby allylic (1) of an B-keto monoenolate the of rearrangement (2 equiv. of HMPT) g"n"rutln of the anion with this basefollowed by silylation toformthesilylketeneaceta|z.Thisderivativerearrangesat40"togive,after a quatarnarycarbon hydrolysis,a B-ketoacid,isolatedasthe methylester3' bearing center. OTMS TMSO cH" o

t r l rMSo^ao

a

I) LiTMPAdEDA 2) TMSCI,N(C2H5b-

t

-

CH,

c(cH3)'

CH3

t

s"cr'fo

c(cH3)

,,

Diastereoselective redwtion ol 11 the ketone 2 with this hydride result (97:3). The samesyn-selectivity is obe was product us the yield is lower. The a speciesof ants. O QMOM i l I CH":CH(CH")"A /BU -IJ -' ' I I MOMO 2, o,e-16.4

I

t CH,

' M. Shimagaki,A. Suzuki,T. Nakata.ar r T. Mukaiyamaand M. Imaoka, Chem.L ' N. Yamazakiand C. Kibayashi, Iarralrrd

(-98:2)

3 7587(1988)' I J. C. GilbertandT. A. Kelly,Tetrahedron,4'

Lithium tri-sec-butylborohydride. ketones(1) are reducedto reductioi.t c-Phenylthio-B-methoxy syn-Selective tri-sec-butylborohydride lithium either (2) by alcohols syn-cr-phenylthio-B-methoxy

i"un' c6H5(CHr)r)-CH,ocH3 i

o I

l

"

SCuH, I rHf,r c6H5(cHr)ry,^-cHpcH3 i:' sec. I OH = 92-95:8-5) 2 (sYntanti

l,A, |rll I |

\,i4,

BFa-.N(c2H5)3

| 1,". lzllu-

cH20cH3 C6H5(CH2)2,,2?

Lithium tri-seobutylborohydride

193

t 9 : . 1 5( 1 9 8 8 ) .

or lithium triethylborohydride.The productsare precursorsto (Z)-allyl alcohols (3).'

11lenediamine(LTMP-TMEDA). J. Drastereoselective [3,3]sigmatropic I 3..i.rcp-ketoestercanbe effectedby r...: '\ silylation(2 equiv.of HMPT) at 40oto give, after lr:t.r. r€arr&nges a quatarnarycarbon bearing 3. br :.:cr

Diastereoselectiveredaction of acyclic urp-dialkoxy ketones.t Reduction of the ketone 2 with this hydride resultsin the alcohol 3 with high syn-selectivity (97l.3).The samesyn-selectivity is observedwith lithium trisiamylborohydride, but the yield is lower. The productwas usedfor a synthesisof ( + )-4, a pheromoneof a speciesof ants.

r

E ^ 8...

O

OTMS

TMSO

l

H.Cr'\(\OcH3

OMOM

i l I cH,:cH(cr!),^A/Bu ' -" ^

c(CHr), )

MOMO

OH

I'rlT:-78'' |

83%

I

OMOM

T

CHr:gglqgr)r^ -'

NPhth

2, ae-16.4

lBu | I MOMO NPhth 3 (97:3't

I oo'

I

CH,

F;

(+)-4

F

' M. Shimagaki, A. Suzuki,T. Nakata,andT. Oishi,Chem.Pharm.Bull.,36,3138(1988). r T. Mukaiyamaand M. Imaoka, Chem.Letters,413(1978). 'N. Yamazakiand C. Kibayashi,Tetruhedron Letters,29,5767(1988).

(-98:2) -

l .

ttu

. eSti).

r!ihoxv ketones (1) are reduced to : : irthium tri-sec-butylborohydride SC.H.

t ' -

' ll't'-"raH.ocH. t ' OH .n anti =92-95:8-5)

t./\ ;ull l | t

\i^,

nFa-,N(c2H5)3

l

CrH
cH2ocH3 n,,CH)T_/

natural product, with an actiuatc product of monensin.This couPlu 2, and proceedsin 87VoYield. Tl

Magnesium-Methanol' (but Mg/CHTOH reducesthese esters Reduction of ar$-acetylenic esters'r also method This yield. esteisin68-72% not the correspondin,".iiJl-r" r"urated groups' to two phenyl ,"au"", double or triple bonds conjugated

- ccoocH3*""9 cH3(cH)4c

cH3(cHt6coocH3

C6H5CH'CH'C#5 CoHrC-CCuH, -6-' \ C.H,CH:CHCH:CHC.Hs *" C.HpIICH:CHCHTC6H5 + C.H,CH:CHCH'CH'C6H5

I rl sorj. Trc 87%12) MrF:

5 . 5I:

t

and A' Monaghan' R Sivakumar' R' E' Zipkin',1'.M,raffer' I R. O. Hutchins, Suchismita, (1989)' Letters'30'55 g. fr,f. nf*iss"ou , Tetrahedron

f f i (ll r )\ anthracene'I Magnesium

: ocH3 ll

\,\.SZ -vg1rff1

I

at 20-60'' of Mg with anthracenein THF This complex is obtained by reaction or dioxane' The THF can be displacedby DME convertedquantitatively into n't!-OlY-O^t::: On protonolyrlr, tt'i' "otplex is THF it behaveslike a diorganomagneslum thracene.In reactionswlth bO' or comPound(equationI)''

hydrolysisof the lactonering. sP oxo group at C?to the axial alco ' B. Bogdanovic, Acc'Chem'Res''21' 261(1988)' bromide' Magnesium u rthesisof the antibioticmonensin Alkynelestercoupling't A key step T :y"t of the aeriveo trom a degradationproduct (4) involves coupling ot'u'n urtfn" iz;' 794

Cleavage of an azctidiu BrCHzCHtBr, cleavesthe ePoxit hydrins2. The N-silYl derivatin to 2 is a u ketonecorresPonding

Magnecium bronide

195

natural product, with an activatedanhydride(1), also an oxidativedegradation product of monensin. This coupling was achievedvia the magnesiumacetylideoI 2, and proceedsin 87% yield. The resultingynone (3) was convertedinto 4 by CH,

qoocooc2H5 Il Ot{ reducesthese esters(but 1 t'r--176 yield. This methodalso o rhenrlgrouPs.

+

: ocH3

CH,

CH,

'C,"f' '" CH,foti

C

Jl

ocH, CH,OTMS

H

I

soocHl 1l.c-H.

I l) BuLi, THF

z1e. lDuzw2

\ ,(. H. + C.HTCH:CHCHzCHzC.II: :::l

C

!v

o-'cH. - scvqu TMS

sl@s

A. Monaghan,and lc: R Sivakumar,

CH, il

n:h rnlhracenein THF at 20-6trinto 9,lO-dihydroantuJ:rrrtatively diorganomagnesium a like th.,\r.

cHi" CH 4

hvdrolysisof the lactonering, spirocyclization, and stereoselective reductionof the oxo group at C7to the axial alcohol(potassiumtri-sec-butylborohydride).

r:r:he\is of the antibioticmonensrn fr''m a degradationproduct of thc

Cleavage of an azetidinone epoxide.2 MgBr2, prepared from Mg with BrCH2CH2Br, cleavesthe epoxideL regiospecifically to the diastereomeric bromohydrins2. The N-silyl derivativeof 1 is stableunder the sameconditions.The ketonecorrespondingto 2 is a usefulprecursorto a carbapenem.

Mrqrnerc(Itr)

ecctrte-IXpberyl dtcuffide

osiR"

OSiR.

" cH") f<"tt'c{7t"' 'oLfu

CHCH,BT

#''"0'i',"r,)"f("' 88%

OH

oh*

anti-Markovnikovadduct' A similar reg< allylacetamideand N-allyltrifluoroacetam The addition to allyl nitrile alsoshou'sso adduct (equationIII)' However, both prc of the nitrile group to provide the samela

(III) CH':CHCH'CN + M

r D. CaiandW. C. Still,J' Org" 53' 4641(1988)' 29' 5197(1988)' Letters' ' Y. UedaandS. C. Maynard,"Tetrahed'on

HOCIICHCHTCI{+ CJ I

sc6H5 (6%)

13' 66' Magnesiumchloride-Sodium iodide' pcatalyzedby MgI' to form p-Keto amides. The carboxylationof ketones and ketones preparation of p-keto amidesfrom keto acidshas been extendedto a neCl" and ZtClzate not useful catalysts' aliphatic isocyanates'Orcf, SnCft'

o

N(C2Hs): Mgl2,

BuNCo conrJcrur* #-

?

t'""

?

cuH,CcucNrmu CHt

(1989)' rL. C. LasleyandB' B' Wright'Syn'Comm''19' 59

: Z . K . M . A b dE l S a m i M i , . I . A l A s h m a r ri 2s23(1988).

disulfide (1)' Manganese(Ill) acetate-Diphenyl in CH'Cl'/trireaction of these two reagents Tire Hydrorysulph"nytoi'i' which are sulfides' ";;;tt gives v'c'trifluoroacetoxy fluoroacetic acid with Jtt* I) (equation acetate allyl The reaction with hydrolyzed to vic-hydroxy sulfides'

Vanganesedioxide. RC=N-+ RCONHT.| HYdrationof ro high yield with MnO: on SiO2,prepa KMnOodissolvedin water. Benzylicoxid

(f cHr:Q116t!oAc

+ Mn(oAc)'+ c#5ssc6H5

1)cHzcrrrcFrc@H ' MnOl/siO,

c6HisCHfHCtlOAc + C6H,SCH'CHCH'OH OAc OH Q19o)

l-Buc:N

-c'H''|"

1-gr

93*

(119o)

l: OH+ cfl5sscJls -@' + Mn(oAc)' (ll) cHr:cHCrloCoCF' HOCHfHcH,oH

SC#' intermeformedvia an episulfonium both presumably affordstwo monoacetates, a single affords II) (equation diate.In contrast,reactionwitrrattyttrifluoroacetate

C6H5CH2C=N-+

Co&l

Illtrasound activation.z Commerr markedlyactivatedby ultrasonicirradtr of allylic or benzylicalcohols.

Mengenesedioxide

OSiR" t. '11 ,CHrcHCll'Br cH,' I

'

oH

.J-irH o' t

197

anti-Markovnikovadduct. A similar regiocontrolobtainsin sulfenylationof Nwith Mn(OAc)3and CuH.SSCuHr. allylacetamide and N-allyltrifluoroacetamide The addition to allyl nitrile alsoshowssomepreferencefor the anti-Markovnikov adduct(equationIII). However, both productsundergoa Ritter-typehydrolysis of the nitrile group to provide the samelactone. (III) CHr:QHCHTCN + Mn(OAc)r+ (CuHrS), -""-+

I

r 1 9 sle7 (1988).

HOCHTCHCHTCN+ C.HTSCH2CHCHTCN

sc6H5 (66Vo)

\er,,nes catalyzedbY MgI, to form Pon .rf 9-keto amidesfrom ketonesand rnJ Z-nClrare not usefulcatalysts' !;- '

> r

CoCl2,H2O,170'

c6H5s\

o o ll

OH (20%)

fl

ll

'c.H.icuiNrmu " l

\^Ao U

CH, lt '.

' Z . K . M . A b d E l S a m i i , M . L A l A s h m a w y , a n d J . M . M e l l o rP, .e/r. kCi .nS1., 2 5 0 9 , 2 5 1 7 , 2s23(1988\.

1989).

rl I . r litc'S€two reagents in CHzClz/tri' ni-::r:luoroacetoxy sulfides, which are t2!::,,n with allyl acetate (equation l)

)(.ll.ssc6H5

Manganesedioxide. RC=N--+ RCONHz.t Hydrationof nitrilesto amidescanbe effectedin good to high yield with MnO, on SiO,, preparedby stirring silicagel with MnSOaand KMnOodissolvedin water. Benzylicoxidationcan be a competingreaction.

l) - CHTCbEFTCOOH - - -

) MnQ/siQ

J{.r )\c + C.HTSCHTCHCH2OH I OAc

t-BuC:N

93C.

(ll%o) A:

l: OH-rr.'-- C.H5SSC6H5

c'H"'a

c6H5cH2c:N

r t-BuCoNH^

o o il- tl

-------+ C6H5CH2CONH2 + CuHrC CNH' (35Vo)

HOCH?cHCH20H -l

SC#' 11i ,rmed via an episulfoniuminterme' Drt\;.ct?t€(equationII) affordsa single

Ultrasoundactivation.2 CommercialMnO, is a weak oxidant, but can be markedlyactivatedby ultrasonicirradiationand agitationin the caseof oxidation of allvlic or benzvlicalcohols.

19t

Mercory(Il) rc€trte

o H

OH

+ )))), 17o CH3(CH2)6CH2OH-;-

,ht\

C.HTCH:CHCHO

C.HTCH:CHCH2OH ff\ 100Vo

\-Jt ,-o H,CoHA-p-r,u.or.

CH3(CHr)6CHO

+ )))),50"

Hg(OAc) THF/H,O -----i' 85qo

5Vo

v ,\

HrCOH i

I

(1988)' rK.-T. Liu, M.-H. Shih,H.-W Huang,and C.-J' Hlu,Synthesis,715 2T. Kimura, M. Fujita, and T. Ando, Chem.Letters,1387(1988)'

"Mercury. Dehydrodimefization. on excitation with a mercury vapor lamp, mercury ts a carbon convertedto an excitedstate,Hg*, which can converta c-H bond into which in dehydrodimerization, result can radicaland a hydrogenatom.This process because useful synthetically been not hasbeenknown for sometime, but whichhas of low yieldswhen carriedout in solution.Brown and Crabtree'haveshownthat this reactioncan be syntheticallyusefulwhen carried out in the vapor phase,in which the reactionis much faster than in a liquid phase,and in which very high selectivitiesare attainable.SecondaryC-H bondsare cleavedmore readily than primary ones,and tertiary c-H bondsare cleavedthe most readily.Isobutaneis is This dehydrodimerization dimerizedexclusivelyto 2,2,3,3-tetramethylbutane. is also also applicableto alcohols,ethers,and silanes.Cross-dehydrodimerization possible,and is a usefulsyntheticreaction.

O

* +cH,oH

O-O.

O*'

ra \/

HrCOH 4

slow reductionof 2 in a basicmedium is a mixture of two products that undergo precursorsto modifiedprostaglandins.' Oxidation of cyclic t-amines.2 Hg(t acid (EDTA) is the cla aminetetraacetic (1, amines 648).This reactioncan be usc

+HocH2cH,oH

O*-u:$* (1989)' I S. H. BrownandR. H. Crabtree, Am. ioc.,111,2935,2946

H8(OA.bED clhq 9tt

f", \*/

f"' o'o \*Ao

l

OH Mercury(Il) acetate. Hydroxymercuration. Reaction of the iridoid glucoside aucubin (1) with Hg(OAc), results in exclusiveattack of the enol ether double bond to give 2. Demercurationwith NaBHoin the usualway affordsisoeucommiol(3). However

"'cH,ou.

l

OH

G Carnevale,E. Davini, C. Iavarone.and ( E Wenkertand E. C. Angell, Syn. Comn .

Memry(II)

OH C.il.CH:CHCHO

,l-r, \

OH

Hg(OAc)2 THF/H,O

-----------'

'../o

85q.

\--1t ,.-o H,CoHA-u-r,u.or.

I{ .CHO :

I

OH I

f""-cu,ou \;

/

3

7

I l) NaoH 7870| 2) NaBH4 | 3) HCr

i .1s 5 .( 1 9 8 8 ) . t u r . , : t l t e s7 : : . - (1 9 8 8 ) .

o^ :

i

r-1

(r

6\

i

o^ {r

\/"'cH,oH

,

* F1

6L

+,r }rcH,ou

H2COH

H2COH

4

5

slow reductionof 2 in a basicmedium is attendedby epimerizationat Coto give a mixture of two productsthat undergo acid-catalyzedcyclizationto 4 and 5, precursorsto modifiedprostaglandins.l Oxidation of cyclic t-amines.2 Hg(OAc), in combinationwith ethylenediaminetetraacetic acid (EDTA) is the classicalreagentfor dehydrogenationof /amines(1, 648).This reactioncan be usedto convertcyclicl-aminesto lactams.

,.'-,.u.CHrOH + HOCHTCHTOH

EDTA Hg(OAc)2, cK2ctz > 93%

CH, - ('llo

fr' .

. : i.

:9{6 (1989).

f",

r

l l - o'o - ' l l \*Ao

\*/

t

OH rr..:,,rrlglucosideaucubin(1) with r:: ,. ether doublebond to give2. (3). However I .:: ,rrl\ isoeucommiol

.CH.OH

HrCOH

O-p-gluc

I

h .r ntcrcurvvapor lamp, mercuryi5 6t'rr crt a C-H bond into a carbon which rc.u.irn dehydrodimerization, ri.: .dcn svntheticallyusefulbecause ou:: .rndCrabtreerhaveshownthat 1 ..:::r.d out in the vapor Phase'in q:- .r rhase.and in which very high x.-.:. .rrcileavedmore readilythan Grr:.1thc mostreadily.Isobutaneis is u:,-- This dehydrodimerization '..-dehydrodimerization is also r t :

NaBH4 cHcll/cHl0H -i------:-----+' 85qa

acetrte

l

OH

E. Davini,C. Iavarone,and C. Trogolo,J. Org.,53,5343(1988) G Carnevale, E Wenkertand E. C. Angell,Syn. Comm.,19,1331(1988).

zffi

MersrY(II)sulfrte

Mercury(Il) chloride. treated with Cyifizatfon of 8,e-unsaturatedamines' Theseamines(1) ' when trans-2'5-disubstiHgCl, or Hg(oAc),, can cyclizepredominantlyto either cis-ot predominatesin t,itea pyrroiiaines(2), dependingon the solvent'The cls-isomer reactionswhenTHForCHClristhesolvent'whereasuseofTHF-HrO(1:1) yield in some providesmostly trans-2,The presenceof water also improvesthe reactions. \ ' : C H . +-

/

4-,1

C.Hi

\H

I

CH, I THF THF/HrO

l) Hgcl2 2)NaBH4

fl

/

cuu,\/"'cu, I

Methanesulfonicanhydride. F riedel-C rafts methanesulfonyla tiot -' with methanesulfonylchloride, but this n halo- or nitroarenes.Reasonablygood 1'r nesulfonylanhydrideand a catalyticamou CI

-ff +(CHrSOr)rO

\

* cuufl^cu, I

CH,

CH,

trans-2 36Vo 64Vo

cis-2 10:90 8 7 :1 3

S. Sato,andl. ltotr.( M. Ono.Y. Nakamura,

(1988)' I M. Tokuda,Y. Yamada, Chem'Letters,1289 andH' Suginome, Mercury(Il) sulfate. or elim' Hydration or elimination of glycats' Glycalscan undergo hydration acid.' acetic ination when treated with Hgso4 in dilute sulfuric acid or aqueous (2)'' This However,o-glucalL is convertedonly into the (1,2-dihydroxyethylxuran Thus 2 can be convefied producthasbeenusedfor a short synthesisof L-hexoses. is convertedinto product This (Mitsunobu). inversion with 3 io the monobenzoate

"€>Bqk""fPObG 3

2, ao+38"

Brzin cHroH f

nzoHp/\o?oH

c-Methoxyallene. Cyclopentannelation(U, 310). Thrs methoxyallene,which.failsto undergoc1 ditions. Actually, the reagent is (methor etherscan be used,but all musthavea dcg cation.t

M. A. Tius.J.-B.Ousset. D. P.Astrab.A H 30,923(1989).

B-Methoxydiisopinocampheylbonnc( I ). I syn-p-M ethoxyhomoallyI alcohok.t - 78'of lithiatedallyl methyletherwith l. aldehydesto providesyn-B-methoxyhom CH. I ' .A,...)rnOCH,

l\*l \l-l I

o 4

l-glucosc the l-hexenulose 4, a known precursor to several L-hexoses including and L-galactose. rF. Gonzalez,S. Lesage,and A' S. Perlin,CarbohydrateRes',A'267 (1975)' 2 F. M. Hauser, S. R. Ellenberger,and w. P. Ellenberget,TeftahedronLetters,29' 4939 ( 1988).

+ CHr:CHCH:OC}q

B-Methoxydiisopinocampheylborane

T': !-e amines(L), when treatedwith llr :,,crther cis-or trans-2,5-disubstire:r: The cis-isomerpredominatesin ; 6 i . * h e r e a su s e o f T H F - H r O ( 1 : 1 ) li(: .:i.o imProvesthe Yieldin some

Methanesulfonicanhydride. Friedel-Crafts methanesulfonylation.r This reaction is commonly conducted with methanesulfonylchloride, but this reagentgivespoor yields in the caseof halo- or nitroarenes.Reasonablygood yields can be obtainedby use of methanesulfonvlanhvdrideand a catalvticamountof acid. CI l

)

r"

+

cH,

'

-

1 T-cgt -

cuHi \'

/

CH,

uI & &

cis-2 10:90 87:13

t:2

cr-Methoxyallene. Cyclopentannelation (l2, 310). This reactionwas mistakenlyascribedto amethoxyallene,which fails to undergocyclopentannelation under the cited conditions. Actually, the reagentis (methoxymethoxy)allene. A few other allenic etherscan be used,but all must havea departinggroupcapableof forminga stable cation.t M. A. Tius,J.-B.Ousset, D. P.Astrab,A. H. Fauq,andS. Trehan,Tetrahedron Letters, 30,923(1989). (1). Preparation.I B-Methoxydiisopinocampheylborane syn-p-Methoxyhomoallyl alcohols.z The reagent2, preparedby reaction at - 78'of lithiatedallyl methyletherwith 1, derivedfrom ( + )-a-pinene,reactswith aldehydesto providesyn-B-methoxyhomoallyl alcohols(3) in 887oee.

a.HrcooH, RC6H')l

g e2qo

{ 3

F

inorron Inrz

BzoH,c/\olou

in,

#...rtocH,

\1,/

scc-BuLi -"" + CH,:CHCH2OCH3 ' tHr $..

Li-

\l./

o 4 L-hexosesincluding L-glucosc

,r-rr* | .."o J OH

t

b ...:.rrc Res.,42,267(1975)' [:. :1'crser. TetrahedronLeuers,29, 4939

R-

t ocH3

-OCHr

,,t-

t

I x'irr.tl

n Y

'M. Ono,Y. Nakamura, (1988). S. Sato,andI. Itoh,Chem.Letters,395

i1r..,.. can undergo hydration or elim!-.:.-nc acid or aqueous acetic acid'l b< . l-ttihydroxyethyl)furan (2)'' This o: . :rc\oses. Thus 2 can be converted u:r' ^r r This product is converted into

rll

?

so2cH3

'?r. : .:i.rs. 1289(1988).

\ -,

/\ ll \?

CI

CI l .s-(^-H 1Mo Ln3)ern' rw'> $4sotc"' I + (cH,so.),o ll | 8500 \?

I

}i

201

cH. '

3 (88-907oee)

_'

oa",

2U2

MelhorY(PhenYtlhb)mettrne

OH

1H. C. Brown and B' Singaram,I' Org',49' 945 (1984)' 2 H. C. Brown, P. K. Jadhav,and K' S' Bhat, Am' Soc', 110' 1535(1988)'

*"ro "*"4r.*lt', -\

T

[(Methoxydimethylsilyl)(trimethylsilylmethy[lithium,

(CE)r?i-CHSi(CH3L (1) 3 + (C.H'),P:CHCOOqIL

ocH3 Thereagentispreparedfromthecorrespondingsilanewitht-butyllithium' ketonesprovides vinylsivinylsilanes,. The reaction of 1 with aldehydesor reaction' lanesvia a Peterson-type Rt-.

_?8. _ * I -3*

Rt-..

*rrc:""t(cH'), (ElZ= 2-3:r)

*r-":o

rT. F. BatesandR. D. Thomas, J' Org',54'1784(1989)' (E,Z).l.Methoxy'2'methyl'3'(himethylsilyloxy)-1'3'pentadiene' ImProved PreParationt: HCo2c2HlNrH

-#.r"''\ll c,4Cc,H, ?

13' 180-181'

3

of the double bond (t-BuOK) prorrd compound(4), which is convertedrnt comp roaceticacid. 1,4,7-Tricarbonll estergroup of 4 to an aldehydegrou 1,3- or 1,4-Diketones.: The to aldehrd t phenylthio)methyllithium alyzedby a Lewis acid to form P-nr migrationof the phenylthiogroup. 1 as shownin thc 1.3-or 1.4-diketones l) BoLr

OH

z),r"ct rrcxl
I " *. ,\-OCH,

,o-rr* ro* "rlo", ".4 f

l

!

sc6H5

"'4::;,jw"'!{**

I l) clc6H4co3H

^ r- 2)NsHcq' ' c.H.-a -6'-) 5rqo

(1988)' rD. C. MylesandM. H. Bigham, Org' Syn',submitted

(cH3LcoK

'-;*L_' methane' Methoxy(PhenYlthio) (2) of the anion (1) of methI,4-Dicarbonyl compounds' The adducts are converted into ct-sulfenyl (n, 316) oxy(phenylthio)methaneand aldehydes and triethylamine(i:1)' chloride aldehydes(3) on treatmentwith methanesulfonyl Reactionof3withawittigorWittig-Hornerreagentfollowedbyisomerization

ll

o ?to"t

c'H'Al

c ( E l Z= l : 9 t 'f.

Sato,H. Okazaki,J. Otera.and H I T. Sato,M. Inoue,S. Kobara,J. Otera.

Methoxy(phenylthio)methcne

Fr, ;o. . ll0. 1535(1988). Li

*.\o.t, HL -.,tt" *""o"n,oi."*j", sc6H5 7

I

*rn.

lCHr)zSi-CHSi(CH3)3 (1) I

ll TF:9.' uonsrFCHCHCoocrH5 . rr s 3 + (CuHr)rP:cHCooc2H5#

ocH3 drnrrrlanewith t-butYllithium. providesvinylsiftrJc. or ketones

4 ro-ro+, crrcoon,Hzo J

o

'C:CHSi(CHr):

tl

RCCHTCH2COOC2H5 rEZ = l-3:1) 1.. .

r1-1.lpeniadiene' 13, 180-181.

.rrtn' \n"

5 carbonyl of the doublebond (t-BuOK) providesa 1-phenylthio-B,1-unsaturated compound(4), which is convertedinto a 1-oxo ester(5) on treatmentwith trifluoroaceticacid. 1,4,7-Tricarbonyl compoundscan be preparedby reductionof the estergroup of 4 to an aldehydegroup and repetitionof the sequence. 1,3- or 1,4-Diketones.2The acetates of adducts (1) of methoxy(12,316)reactwith enol silyl etherscat(phenylthio)methyllithium to aldehydes ketones(2) with a novel alyzedby a Lewis acid to form B-methoxy-1-phenylthio migrationof the phenylthiogroup. Theseproductscan be convertedinto either as shownin the formulation. 1.3-or 1.4-diketones r) Buu

OH

', ''*

f

c.t{ ,o"' cHloH'

a.",\ocu,

$CoHt

*''., a.",h("u", 1lli',!r"af.t*tn,r,' ocH3 o ,

sc6H5

o

l l l - c.H.c

Y

cH3

\o"",

l) clc6H4co3H

r%A"u",ffi(.ut' o

u : : r . :, l 9 8 l l ) . -2

:r. 2t of the anion (1) of meth-l.nr dr€ convertedinto o-sulfeny' (1: l)nr. chlorideandtriethylamine fr r.rgent followed by isomerizatioo

(cH3)3coK ?tu"' t'l' -, vc.H.A,'\rCuH' 6r 15 stqo

"4 ll

o

,r*'

? c.H.,\'^/cuH' "u- -t

ll

o

(E/Z--1:9\ T. Sato,H. Okazaki,J. Otera,and H. Nozaki, Am. Soc.,ll0, 5209(1988). (1989) Letters,30,91 T. Sato,M. Inoue,S. Kobara,J. Otera,andH. Nozaki,Tetrahedron

2M

3

Methyhluminum bb(2'Gdi.r.butyl-4-methylphenoxide)

Conjugate addition to quinone mo.d 1,2-addition with (CH3),CuLi and mosr Gr achieved by complexation of the acetal sil

4-Methoxy-2,2 r6,6-tefiamethyl-l-oxopiperidiniumchloride'

qcFI, cH,J l,cu.,(l),13,183. cn,/\N,^cu. ' t l

L r

+ RLi

ocr

cH3o-

Selectiveoxidation of hydroxy groups of esters.t The reagentfails to oxidize a primaryhydroxylgrouplocatedin the a- or p-positionto an estergroupbut does oxidizean hydroxyl group in a more remoteposition.

o o l l l l y'1Co(co(cH2),oH ----i---*l ll ll I \AcotcH2)4oH

stco

'M. Yamaguchi, (1988). Letters,29,5671 T. Takata,andT. Endo,Tetrahedron (MAD, 1), 13, 203. Methylaluminumbis(2,6-di-r-butyl-4-methylphenoxide) Conjugatereduction of enones.r This reduction can be effectedwith 2 equiv. of Li(Bu)(r-Bu)rAlH (2) and of MAD. The choiceof solventscan affectthe selectivity. Stericallyhinderedketonesundergo1,4-reductionvery readily.

|,.2,

,\

o

<"^'"t.'-

A A X " cH,\lcH,

(45Va)

(E)-C6H5CH:CHC-C6Hr(CHr),

o

rru

1d

85Vo 649o

EIZ

C H3

zI

o

cn,\icn,

cl

]2

Claisen reaffangementof allyl vinyl ct ethers(3) of sec-allylicalcoholsin the pre Rearrangementof the optically active5 i particularlyin the caseof 1.

3 l, - 20' 2,-18"

#i:x',{,

CH,

Methylaluminum bis(2,6-diphenylphenor (2). 2,6-di-r-butylphenoxide)

,-ruAo/

o CH,

K. Nonoshita,K. Maruoka, and H. Yamamo A. J. Sternand J. S. Swenton.J.C.S.Chem

cH3Al [ -o-c6H3(c6H5)-2,6 1

o

o

=Bu

\AcotcH2)3cHo

ll

il

R = CoHs

cH3VcH3 (49Vo)

" l-Bu

I lR

\o )

CH,' -

(

,-"r)t

5 I

.,

C6H5CHTCH2C-C6H/CH3\

o

LK. Maruoka, K. Nonoshita,H. Banno. and H

Methylrluminum bis(2'Gdipbenylphenoxiile)

205

Conjugateaddition to quinone monoacetals.2 Thesesubstratesundergo only 1,2-additionwith (CH:)zCuLiand most Grignardreagents,but 1,4-additioncan be achievedby complexationof the acetalwith 2 equiv. of 1.

chloride'

3. I r-i

l,c6H5cH! +RLi -"' ,

lli':l

tt I

"",o4il,

cH3o fhe reagent fails to oxidize !.' lrr:r ,r l() an estergrouP but does

A

R = CeHs = Bu

78Va 42Va

I K. Nonoshita,K. Maruoka,and H. Yamamoto,Bull. Chem. Soc.Japan,6l,2241 (1988) 2 A. J. Sternand J. S. Swenton,J.C.S.Chem.Comm.,1255(1988).

o Methylaluminum bis(2,6-diphenylphenoxide) (r); Methylaluninum bis(4-bromo2,6-di-/-butylphenoxide) (2).

\/CO(CH')PH

,t-colcHr;.cuo

CH3AI [ -O-c6H3(C6Hr)-2,6 t

I (J

I , : . , ' . 2 9 .5 6 7 1( 1 9 8 8 ) .

oridel (MAD, 1),13, 203. tr,': .Jn be effectedwith 2 equiv. i( .'l .()lvents can affect the selecej uilr,rn very readily.

CH3AI[ -O-

]2

2

Claisen rcarrangement of atlyl vinyl ethers.t Thermal rearrangement of vinyl ethers (3) of sec-allylic alcohols in the presence of I or 2 leads to the aldehyde 4. Rearrangement of the optically active 5 is accompanied by transfer of chirality, oarticularlv in the case of 1

a"'r^."*,- tr ) l ,A ,-rrAo/ 3 l,-20" 2, -780

H _ o H

rr

t

l

cH,AlcH' (497o)

c. I t.cHrcH2c-c6Hr(cH3)3

o

-2,6-di-l-Bu]t C oHr-4-Br

8570 6490

4 E I Z = 9 7: 3 - -7 : 9 3

?',

9H, /^\ i l

a cH" '

ln "'\o/ ,-Bu

5

I

.,

ll

c' o

), i-Bu-

l

CHO

CH.

I /'\ -' \ l C l H l O -Bu-i

(z)

(E) 98:2 1 6: 8 4

K. Maruoka. K. Nonoshita,H. Banno, and H. Yamamoto,Am. 'Soc.,110,7922(1988).

N-Me0y''ldimefhyleninoocetohydroxrmicecid

2M

Methyl cyanoformate,12, 321' Supplier:Aldrich' generatedby reduction Reductiveacylation of eno'ei'i The lithium enolate with this reagent reaction p-keto esterby of enoneswith LilNHr is convertedto a in ether(THF promotesO-acylation)' H NccoocH3

,eDlul[',"co] e

h

14ca

e

.

r

l

l,^

t

l

l

t

or''.'y''J :

l

I CH,

fi"'

ff'",* t" o^Y^rr, Cf*

L-s:2Nrc951-

'Yr

62%

co"cH"

CH,

.

co2cH3

"

' S. R. Crabtree,L. N. Mander,and S' P. Sethi,Org. Syn.,submitted(1988)'

acid, (CH3)TNCH,CO-<:: N-Methyl-2-dimethylaminoacetohydroxamic

Methyl (R)'3'hydroxybutyrate' (l)' Chiral p'lactams.t The reactiono{ on treatment with lithium hexameth;-k imine 2 to provide a single crs-azeudtm

r L

i,", I '?''

(r).

y'n..

?'

cH^

| ,o,rrt

l-

ocHJ

b

OH

I

I

cooc6H

ry. DUAI. I rl

51 ' J. Rodriguez Syntftesr' andB. Waegell,

(R)-1

under neutral condiTransacylation. The reagent effects transacetylation tions.

A "Y

*r

,"+P^ g, gH +l*5 | ."5-toocH'

I

OAc

o tl ",c\An

coocH3

fi"'

(r)

dine.

H

a 3:1 mixture of The samereactioncarried out on R-( )-carvone(L) affords two esters(equationI).

l) LialH:

Methyl hydrogenmalonate' HOOCCH:C is availablefrom Fluka. Methyl2,4-pentadienoates. Thesed yield by reactionof cr,p-enalswith I in I

+ I ----t

a-\

\a

t

t

l

,zcHt + (CHr)'NCH'CON.

-ococH3

cooc6H5

|

-o"

+

(9r-987a)

I + CHTCOOH I M. Ono and I. Itoh, TetrahedronLetters,N,207 (1989)'

I N. Oguni and Y. Ohkawa, J'C'S' Chcttt'

Methylketeneimines,CH3CH={-:!/ 12+ 2lCyctoaddition wirt aldYt usefulfor this cycloaddition'but trco or Eu(hfc): are very efficient catdysts (trans)-2-iminooxetanes(2) in the cas

Methylketeneimines

fh

um .nolate generatedby reduction ) t'.rcr b! reactionwith this reagent

-'l

A)7

Methyl hydrogenmalonate,HOOCCHTCOOCH3(1). Methyl potassiummalonate is availablefrom Fluka. Methyl 2,4-pentadienoates. Thesediunsaturatedestersare obtainedin >85Vo yield by reactionof c,B-enalswith 1 in pyridine catalyzedby dimethylaminopyridine.

\acoocH3

+

€ther

","YA"

-1%

/') CH,

",c;,A.Aocn, * 1 -ry:PY1lIlCH, (E)-2

r n , \ n c ( l ) a f f o r d sa 3 : l m i x t u r eo f

CH,

QH,

,

CHt

+

/ tii :li

rJ. Rodriguez (1988). Synthesis,534 andB. Waegell, Methyl (R)-3-hydroxybutyrate' (1). Chiral S-lactams.t The reactionof l with (CrH,)rZnin THF providesa, which providesb, which reactswith the on treatmentwith lithium hexamethyldisilazane (3), an intermediateto thienamycin. imine 2 to provide a singlecrs-azetidinone

3:1o OH

r^i \, r

submitted(1988).

t cH-!coocH3 (R>r

LNtSi(CHrhl, ---:+

,zcHt CH,)2NCH2COn-O"

cil.

C-CCeHs

|n..:.ct\lationunder neutral 3 (r'R,3R,45) b .zCHt rClt r.\CHTCON.

-ococH3

|

-o"

t

I + CHTCOOH

|

. r\!

)

I N. OguniandY. Ohkawa, (1988). Chem.Comm.,1376 "/.C.S. (L). Synthesis.' CH:CH:C:NAr Methylketeneimines, 12+2lCycloaddition with aldehydes;2-iminooxetanes.2 Lewis acids are not usefulfor this cycloaddition,but tracesof lanthanideshift reagents,Yt(fod)3,Yt(hfc)r' or Eu(hfc)3are very efficient catalystsfor cycloaddition to a mixture of (cr.s)-and (2) in the caseof both aliphaticand aromaticaldehydes' (trans)-2-iminooxetanes

208

Methyl (E)4uethoxy-2.oxo.&buteno&te

TheZlE ratio is largelyindependentof the lanthanidecatalystand of the aldehyde, except in the case of methylketeneN-benzylimine.Dimethylketeneiminesalso

1+RCH:O#

c",

c", . /*

,L;

R''

:

-1:l

(z)-2

ot l

cH,o&o , I

,aoC'Ht

+ l l CHt

ocH3 I

o

(E)-2

undergothis cycloadditioninT0-90Vo yieldeventhougha quaternarycarboncenter is formed at C, of the adduct. 'Typicalpreparation: A. Battaglia, A. Dondoni,andP.Giorgianni,J. Or9.,47,3998(1982). 2G. Barbaro,A. Battaglia, andP.Giorgianni, ibid,53,5501(1988). Methyllithium. Decarboxylation of carboxylic acids.t Reaction of methyllithium with nonenolizablea-phenyl-or c-phenythiocarboxylicacidssuchas L in HMPT resultsin a Haller-Bauer type fragmentationwith lossof CO2.The intermediatecarbanion can be trappedby variouselectrophiles. COOH I

l) cH3Li, HMPT

CH3(CHr)5-i-cH3 2!9:----, 83qo I sc6H5

CH3(CH2)5qHCH3 -l

to{

"""

_ /*

^R " l _ J

ll rn 5'

ocHs e n d o - 2( 6 : l \

? (ot" r+ll \oo.

tr*oucHro\uY rr ; )v/o Y

I octt

endo-4(>15'lt W. Trowitzsch,Z. Naturforsch.8..328. l(| : D. L. Bogerand K. D. Robarge.l. Org -S

sc6H5

si(cH3)l

l) cH3Li.HMP.

2)crs(cH3)3> cH3(cHt5-c-cH3 r

(l pMethylphenylsulfonyldiazomethrnc (l). Preparation.' sec-Homoallylic alcohols.z Reactx vides the sulfone 3, the anion of which ,

sc6H5 'J. P.GildayandL. A. Paquette, (1988). Leuers,29,4505 Tetrahedron

o il

Methyl (E)-4-methoxy-2-oxo-3-butenoate, CH3O2CC-CH:CHOCH: (1). Preparation.t Diels-Alder reactions; carbohydrates.' This B,^y-unsaturateda-keto ester undergoesDiels-Alder reactionswith electron-richdienophilesto provide proreactionof 1 with ethyl vinyl tectedsugars.The thermal and pressure-promoted ketone providesthe endo-adduct2, which can be convertedin two stepsinto the 3. The samereactionof I with (Z)-\-acetoxy-2-benzy' ethyl p-mannopyranoside and givesthe endo-adduct4, which can loxyethyleneis even morc endo-selective, be convertedinto a derivativeof benzylDL-mannopyranoside.

OH

oA--cH' t.

I, HBFd + 13qa

ocHl I

nnl

d

R'

3

2, R = (CH2)2C6H5 R'= CH:

u r ti : ." t R

s

p-Methylphenylsulfonyldiazomethane

n:hanidecatalystandof the aldehyde, also z\.rmrne.Dimethylketeneimines a\R )

4",

o rlkbt

a"ro\o \

,

/* + l l ..1-O -l:1 R''

I

8",

+

ocH3

o

(E)-2

|

-'*-

,/.OC2H'

l. Org.,47,3998(1982). r.:: i' (iiorgianni, u 5-t 5501(1988).

R;.:Jrrorof methyllithiumwith nonrfi- ,.:dssuchas1in HMPT resultsin r : ( O.. The intermediatecarbanion

oc2H5

.",o lilol,f,l?":;"

*r\7ot'",

rc- :hougha quaternary carboncenter

ocH3 or--3

e n d o - 2( 6 : l )

l) H.. PdC, 57qo

(o"' I + ll \oo.

OBzl

,roo. cH3o --+ 5uva

zt r-ierH..

'

AqO. Pv, 689o

A ^n

) nLv

OAc Dr--5

endo-4(>45:l)

n *

I W. Trowitzsch , Z. Naturforsch.B.,328, 1068(1977). 2 D. L. Bogerand K. D. Robarge,J. Org.,53,5793(1988)

'tt,rCHJs$HCU, I

sc6H5

7 -

(tosyldiazomethane), p-CH.C.H.SO2CHN2 p-Methylphenylsulfonyldiazomethane (l). Preparation.' sec-Homoallylicalcohols.2 Reactionof a sec-allylicalcohol(2) with I providesthe sulfone3, the anion of which can be trappedby an alkyl halide to give

si(cH,). l ,II,(CHJs-!-CH, I

so2c7H?

sc6Hs .:: '

OH

19 -1505(1988).

o I

Ci: r CC-CH:CHOCH:

|

"p.\z-uHrl R' (1). Prep-

a-keto ester I::. p.1-unsaturated dienophilesto provideproJr,':-r-rch on: '::J reactionof L with ethyl vinyl a: ': convertedin two stepsinto the Ir,.: ,,i I with (Z)-1-acetoxy-2-benzy4, which can hxl:::r.'r the endo-addttct rt:.,::r,rpvranoside.

^-_

-t ,

2, R = (CH2)2C6H5 R'= CH:

HBFd

r;-.

QCH2SO2CTH? r) BuLi,rHF 2)Bul | ^_-

-

n'\zCH' I R'

"\rt", " l 4

.,* | 2BuLi, '- -JrHF. HMPr

Ho-r'Bu I

I

5

Bu

R'

3

R^/

o

I R'

2r0

Methylsutrenyl Hduoronethmesufonote

4. In the presenceof HMPT the anionof 3 undergoesa [2,3]Wittigrearrangement to provide an unstablealdehyde,which is trappedby an alkyllithiumto give (E)homoallylicsecondaryalcohols(5). 1A. M. vanLeusenandJ. Strating,Org. Syn.,57,95(19'17). 2R. BrticknerandB. Peiseler, Tetrahedron Leuers,29,5233(1988).

9-2 3-Cletnaty

Methyl (Z)-3-phenylsulfonyl-2-propenoate, C'HTSCH:CHCOOCH3(1), m.p.51".

d This vinyl sulfone can be obtained in 70-85Voyield by reaction of methyl propiolate,sodiumbenzenesulfinate, andboricacid(1.5equiv.)in THFi HrO (1:1) catalyzedby BuaNHSOa.' B(oHh,

Hc-ccoocH, + cnHrSorN.JqIHq- 1

?o.

I

/ | CH-CH,

+ l

; * l l

+

AcO

o tl

OAc

(oo' o'oM\,sc2H5

9A. +

.,.\....COOCH3

/\*/COOCH3

r : r l lI

I

CH(-\/\SO2C6H5

protectedderivative (c - 3) of glucosc exclusivelybecauseof the 2-acyl sube

rF. Dasgupta andP' J' Garegg.Carboht

Methyl p-tolyl sulfoxide' 14, I l5' u,P-SulfinYl ePoxides. The'Y
"'T?\ o

cr|6

2,op+2ff

cufJ".SO2C6H5 Naoc6H5 I

6/ycoocu' CH/\\/ Vinyl sulfonesare reactivedienophilesin [4+2lcycloadditionsto provide substitutedcyclohexenes.2 IG. C. HirstandP.J. Parsons, (1988). Org.Syn.,submitted 2P. L. FuchsandT. F. Braish,Chem.Rev.,E6,903 (1986). Methylsulfenyltrifluoromethanesulfonate, CH.SOTf. The reagentis obtainedin situ by reactionof CH,SBTwith silvertriflate. Activation of thioglucosides. Thioglucosidesare usefulfor glycosidationsince they are more reactivethan glycosylhalides.They are known to be activatedby methyl triflate, but this triflate is a potent carcinogen.Methylsulfenyltrifluoro(1) is also an activator and has the advantagethat it can be methanesulfonate (B-2) coupleswith a-opreparedin situ. Thus the 1-thio-B-o-glucopyranoside

yield, can be convertedin two steP epoxidesundergoready eliminadon cupratesto provide homoallylp-h1d to homoallylico-h1d rearrangement

(SR)-4+ CrH,,- _r,-).Cu(Ll-

I G. Solladid, C. Hamdouchi, and \l

\'

Methylptolyt

.ri, \c\ a [2.3]Wittigrearrangement xJ rr an alkyllithiumto give (E).--r | 1 9 . : . : . :{ 1 9 8 8 ) .

(oo' o'ooM\,sc,H,

cuHfto +

culfodde

2rl

I, CH?cb ---+ 96*

o

AcO

OCH,

F-2

cr-3 -glucopyranoside (4) 3-(Ietraacetyl-po-glucopyranosyl)-a-o

L : ( l l : C H C O O C H 3( 1 ) ,m . p .5 l o .

(4) almost protectedderivative(o - 3) of glucoseto give the B-linkeddisaccharide exclusivelybecauseof the 2-acylsubstituent.

a(. r ield by reaction of methyl r : . j , I 5 e q u i v . i)n T H F / H , O ( 1 : 1 )

rF. Dasgupta Res.,lTl,C13(1988). andP.J. Garegg,Carbohydrate Methylp-tolyl sulfoxide,14, 115. o.,p-Sutfinylepoxides. The 1-chlorop-keto sulfoxide2, preparedby reaction of methyl chloroacetatewith the anion of methyl (R)-p-tolyl sulfoxide(l) in 83%

x ::

-

l.:t

ll

,/\/COOCH3

i l i l l CH^./-

:

crz;.,^tsl'q"'

9A. : l

l "so2C6H5

o

i\.'

DTBAH -) cra.,:s{t'E "' es*

I

T\'

o H 6

6

3 (95%de)

2,ae+26P

ur"frr"o

I \aOc6fij

+

l-,,^"""At

ot

lcoocH:

1i'^\v

- I -rcloadditions to providesub-

I --'

i\, o

(SR)-4, oo + 239o epoxide4. These yield, can be convertedin two stepsinto the (SR)-ct,B-sulfinyl do reactwith cyanobut epoxidesundergoready eliminationwith basicreagents, Pummerer undergo p-hydroxysulfoxides (5), which cupratesto providehomoallyl to homoallylica-hydroxyaldehydes. rearrangement

i( t l : The reagent is obtained in i- .:: J u\eful for glycosidation since b<. .,rc known to be activated by r:: :e n. Methylsulfenyl trifluoroh.,. :hc advantagethat it can be t n , . . J c 1 B - 2 ) c o u p l e sw i t h c t - o -

(SR)-4+ C,H,,\Z):u(CN)Li,

;f

C5H,,--/,A=-\,

o 1

5, crp + l79o

rG. Solladi€, C. Hamdouchi, and M. Vicente, Tetrahedron Letters,29,5929 (1988).

2tZ

Molybdenumcerbonyl

Methyl(trifluoromethyl)dioxirane (1). This compoundhas been obtainedby oxidationof 1,1,1-trifluoro-2-propanone (Aldrich) with potassiumoxomonosulfate.It is about as stableas dimethyldioxirane, but is markedlymore reactivein oxygentransferreactions.Thus it converts

oLi I

I + CHrCH:COSi(CH'\

R.C - - O (l) > <-o t cH;

phenanthrene to the 9,10-oxide within 5 minutesat -20'.It can alsooxidizecH bonds.Thus cyclohexane is oxidizedby l" to cyclohexanone (-20",95% yield).1 Epoxidation of enol ethers.2 This dioxirane can effect epoxidation of such hinderedenol ethersas 2. A similar reactionof 2,3-dihydropyranwith 1 affords the epoxidein >92Vovield.

>.:.<:::'

I M. Bottrill and M. Green./.C.5 Dth r A. J. Pearsonand V. D. Khetani.,l O

."".,,.l;..o""" R..,o.. /ocH3 94qo

.cuH,

R,

R = adamantyl

3

'R. Mello,M. Fiorentino, O. Sciacovelli, andR. Curci,J. Org.,53,3g90 (l9gg). 2L. Troisi,L. cassidei,L. Lopez,R. Mello,and R. curci, Tetrahedron Leuers,30,2sj ( 1989).

Molybdenum carbonyl. Cyclohewdiene-fuIo(Co)rlndenyl complexes. The reaction of 1,4-dimethyl1,3-cyclohexadiene with the dimer'of InMo(CO,) (In : indenyl)providesthe complex1(c/. Mo(CO),Cp complexeswith cyclohexadiene,L2,332). Reactionof

Montmorillonite. Michael addition to a,p-crc,n (Al-Mont') is a very effectivecatal; or silyl enol ethers to c,p-enoatcs efiectivethan Lewis acids,which are It also facilitatesMichael additiontr Examples:

osi(cH.).

t

cH3o -

cH'\
CHr* I \.

[lnMo(co),.1,. A8BF.. cH,cL , s2%

ll cHr

I,lo(CO),ln

cH,\:4{

.rVIo(CO)rtn '

*" (-A.i: ......,(__4"'

-

+ CHrAt'/Cm

CH,

,*l*'*(l*", I

Al-Mont

osi(cH3)l

cH,ooc-..'4-1ocH, I with nucleophiles(Grignard reagents,enolatesof ketonesor esters)resultsin substitutionstransto the metal to provide a quaternarycenter.2This technology hasbeen usedto preparethe cls-bicycliclactone3 in high yield.

CH,

CH,

2L3

Monhorillonite

oLi n,.: :.1.1-trifluoro-2-Propanone lr,r: .rsstableas dimethYldioxin):(r r!'actions.Thus it converts

L + CHrCH:COS(CH3)3 ------,

/ Mo(CO)"In

cH3y4(

| ,cH(cH3)cooH v...cH3 (a) 93% | No'PF;, cH3cN ovaall e J

a: lrl'. It can also oxidize Cf(::.\.rnone ( - 20', 95Vo yield).1 ..,:. cffect ePoxidation of such i :'Jrhrdropyran with I affords

I M. Bottrill and M. Green,l.C.S. Dalton,2365(1917). : A. J. Pearsonand V. D. Khetani,J. Org.,53' 3395(1988)

R /r)\/ocH, 'c5H5

R

r. .' / )rt' . 53. 3890(1988). ( -: -t. TetrahedronLetters,30, 257

. Thc reactionof 1,4-dimethYlIn - indenyl) providesthe ) 12,332).Reactionof hcr.rdiene.

Montmorillonite. montmorillonite Michaetaddition to a,F-enootes. Aluminum ion-exchanged (Al-Montr) is a very effectivecatalystfor Michael addition of silyl ketene acetals catalystis more or silyl enol ethers to d,B-enoates.In fact this heterogeneous amount' in a stoichiometric required generally which are acids, Lewis effectivethan to o,B-enones.2 addition Michael It also facilitates Examples:

osi(cE)3

+CH,*coocH3

cH,o\ -l:r :

'

cH3v.-r('

_1\

I

D^Mo(CO)rln

\./...R

o'-"il;-** 6H'ooc.try'l4o*, = 27:73 sYnlanti

rs*

-cHt cHt{-'"ooan,

,*f iilf;,ll"

| I r't-uont

) .

'iie s ,.r tonesor esters)resultsin This technology It.rr.rrv center.2 yield. 3 rr high

osi(cH3)3

CH,

CH, |

b.",

f",

osi(cH3)3

cH'oocfr/ocH, t ' t CH,

CH,

tn,

cH3oocvvcoocH3 -

l l cH" cH \osi1cH,;, cun,/

214

MontmorillDnltel(SF

I M. Kawai, M. Onaka, and y. Izumi, Bult. Chem. Soc.Japan,6l, 123:-(1ggg). 2 ldem, ibid.,61, 2157(1988).

Montmorillonite and Fluka.

KSF. This is an acidic but noncorrosive clay available from Aldrich

Dithianes, thioacetals and -ketals, enol thior ethers. This clay is a useful catalyst for reactions of ketones with thiols. The condensations are usually conducted in refluxing toluene with a Dean-Stark trap for water.r

o /-'.-."''

t

l

+ C.HTSH

l-(1-Naphthyl)ethylamine.C Alkylation of a-nitro La nitro ketonesto cyclic 3-suh dianionof an c-nitro imine (

M-KSF )

o--.i.1 NO, t -

' B. Labiad and D. Villemin. ,Svn.

143(1e8e)

a-'f I

I

il H,nn, ----:--+ 65-80%

I

\-, I

particularlywith sec-Bulrrn positionadjacentto the imrn reductionand eliminationro alcohol,usuallyat room temf Asymmetricalkylationof aminein the firststep.:Besl 1 coordinatinggroup. However andmoderatediastereoselec rncreases the optical yield ro Evidentlyan amide baseplal' ably by servingas a ligandfol

l.

(1988). . ' . ; p a n . 6112, 3 7

)r: '.r\ e clayavailablefrom Aldrich )iol ethen. This clay is a useful are usuallyconhc .,.ndensations ti::

lrrr watef .r

QH, (1). CT.HTCHNH, 1-(1-Naphthyl)ethylamine, Alkylation of a-nitro keto imines. The key step in a conversionof cyclic cnitro ketonesto cyclic 3-substituted1-nitroalkenes(4) involvesalkylation of the dianionof an a-nitro imine (2) or hydrazone.The dianionsare easilygenerated,

\.2''^:

+

J.; 9,-

Q4Vo) : . i e m . S y n t h e s i s ,1 4 3 ( 1 9 8 9 ) .

To'

/'o"

(,

o-.--*--o-.--N H

HrNR,&i-*'

,;a. (-,

o-_;,.o._n

ll liR*,i"*'"' /*f*-*' ---;-";(_^*,

J

c"ct, zo-or, I Huen.. ovaallJ CH,OH

NO,

I

a/\

|

-v-\R,|

+ H,NRI

4 particularlywith sec-Bul-iin THF/HMPT at -78", and alkylationoccursat the positionadjacentto,the imine or hydrazonegroup.The productsundergofacile reductionand eliminationto 4 with NaBH, and CeCl. (2 equiv. of each)in an alcohol,usuallyat room temperature.r Asymmetricalkylationof the intermediatecan be effectedby use of a chiral aminein the firststep.rBestresultsare obtainedwith (S)-f eventhoughit lacksa coordinatinggroup.However,useof only sec-Buli asthe baseresultsin low yields but useof LDA (1 equiv.)andsec-Buli(2 equiv.) andmoderatediastereoselectivity increasesthe optical yield to 79Vode and to 877o de if HMPT is also present. probEvidentlyan amidebaseplaysan importantrole in the diastereoselectivity, ably by servingas a ligandfor the dianion.

Nickel cerbonyl

o-.;.o-r"

l) LDA, r?c-Bul-i THF, DMPU 2) cH'=CHCH.I.-90'

HC:CSi(CHr), + CH,: CHCH

-:----:--------74%

(907o de\

rS. E. Denmark, Org.,53,1251(1988). andR. Lueoend,J. J. A. Sternberg, 2S. E. Denmark (1988). andJ. J. Ares.Am. Soc..1f0.4432 Nickel boride. Deselenationt C-Se bondsare cleavedreductivelyby nickel boride in methanol in generallyhigh yield. This reductioncan evenbe more facilethan reduction of C=C bonds. rT. G. Back,V. I. Birss,M. Edwards, (1988). andM. V. Krishna, J. Org.,53,3815 Nickel carbonyl. Aziridine ---+p-lactam.r This transformationcan be effectedby insertionof CO into the N-C bond of an aziridine.Thusreactionof N-benzyl-2-methylaziridine (1) with lithium iodide in refluxingTHF providesa lithium dialkylamide(a) that reactswith Ni(CO)r to form the B-lactam2 in 5lVo yield. Both reactionsprobably

B

z

l

f

L

i

I W. Chamchaang .l C I andA. R. Pinhas. ' F. Camps, J. Coll,A. Llebaria.andJ V ' K. Kaneda, Y. Fujiwara. T T. Uchiyama,

Nickel(Il) chloride/ Zincl Pyridirc. Conjugate addition of RBr to o, NiClr'6H,O, zinc (2 equiv.). and 1 mides(iodides)to electron-defioent( halidescan undergothis reaction.A t bersof 20or more.A numberof baset, DBU; but not TMEDA or 2,4.Gcoll

C.HTCH:CFIBT+ CI:CHCOOCJ (E or Z)

l

CHrCH:CHBr + CH2:CHC0OI

cHl

lYt,'-ctt"i

t",'

(z)

P. Hopp,andP. Holl. Ica R. Sustmann, proceedwith inversion;and,indeed,l-benzyl-cis-2,3-dimethylaziridine is converted (37Vo yield). by this procedureinto 1-benzyl-cis-3,4-dimethylazetidinone Cyclocarbonylation; cyclopentenones.2The adducts of allyl halides and alcan be convertedinto mono- or kynes,3particularlythose with cls-configuration, disubstitutedcyclopentenones by reactionwith Ni(CO)ain CH3CNcontainingCH3OH and N(C'H')..

o-Nitrobenzenesulfenylchloride' o'O Prctection of amino groups. Th ful for protectionof terminal amino groupsof basessuch as adenine-Th glycosidebond. It is removableb1-n is also stableto phosphorylation.Tb

o-Nitrobenzenesulfenyl chl oridc

217

s(cH3)3 ''"-;-o't"

HC:CSi(CE)3 +CHr:611"t ", Il$11

F

tO CHr_-- I Ni(co)r,Ntcztts)r o)% cH3oH,cH3CN J

(X)Vo de)

o c . , ) r { . .s 3 .1 2 5 r( 1 9 8 8 ) . l:-

cH2coocH3

.,r\S).

by nickelboridein methrc.iuctivelv n . \.n be morefacilethan reduction X " - : , . r .l O r 9 . , 5 3 , 3 8(1159 8 8 ) .

B: 'r rrn be effectedby insertionof :r. : :r of N-benzyl-2-methylaziridine r : r - . . , l i t h i u md i a l k y l a m i d(ea ) t h a t | <. r reld.Both reactionsprobably

I W Chamchaang .l.C.S.Chem.Comm.,7l0(1988). andA. R. Pinhas, rF. Camps, (1988). Leuers,29,581l J. Coll,A. Llebaria, andJ.M. Moret6,Tetahedron ' K. Kaneda, Org.,U,55(1979). T. Imanaka, andS.Teranishi.J. T. Uchiyama, Y. Fujiwara, Nickel(II) chloride/ZinclPyridine. Conjugate addition of RBr to a,p-enoates.t A Ni(0) catalyst formed from NiCl,'6H,O, zinc (2 equiv.), and pyridine can effect addition of alkyl broC-C double bonds. A wide rangeof organic mides(iodides)to electron-deficient for turnovernumhalidescan undergothis reaction.A traceof water is necessary 2,4-lutidine, bersof 20 or more.A numberof basescanreplacepyridine:ct-picoline, DBU; but not TMEDA or 2,4,6-collidine. NiCl2' 6H2O, Zn,

C.HTCH:CHBr + CFL:CHCOOC2H5-#-(E or Z\

L,

-N4o

-- c',l JJJJJ 2

is converted <.. -- .i-dimethylaziridine (37Voyield). hr .,zstrdinone T:.: .rdductsof allyl halidesand alic: ;.rn be convertedinto mono- or \r ( ( ) t, in CH,CN containingCH3OH

C.HTCH:CHCH2CH2COOC2H'

CH,CH:CHBr+CH,:Q|{cocH3_CH,CH:CHCH2CH2cocH3

(z) rR. Sustmann, (1989). Letters,30,689 P.Hopp,andP.Holl,Tetrahedron (l), 10, 277. chloride,o-OzNCuHoSCl o-Nitrobenzenesulfenyl (NPS)group is useProtectionof amino groups. The o-nitrobenzenesulfenyl ful for protectionof terminal amino groupsof peptidesand the exocyclicamino groupsof basessuchas adenine.The group also increasesthe stability of an Nglycosidebond. It is removableby reductionwith BurP in aqueousdioxane.'2It is also stableto phosphorylation.Thesepropertieshave been used to synthesize

zlE

iV.(pNltrobenzylidene)benzcnesufionemftle

in which a peptideis joined via a phosphodiester nucleopeptides, bond to the 5'end of a nucleicacid. 'J. Heikkilii,N. Balgobin, andJ. Chattopadhyaya, ActaChim.Scand. 8.,37,857(1983). ' E. Kuyl-Yeheskiely, C. M. Tromp,A. W. M. Lefeber,G. A. vanderMarel,andJ. H. van 4. 6515(1988). Boom.Tetrahedron. 2-Nitrobenzenesulfinylchloride, 2-OrNC6H4SOCI. RlS(O)R'. This sulfinylchlorideis oxidizedby potassiumsuperoxide RrSR2--+ to a sulfinyl peroxy intermediatethat oxidizessulfidesto sulfoxidesat - 25" in >90Voyield with only tracesof the corresponding sulfones.'

o *#L 2-o2NC6H4SoCl + KOr+C.HTSCH,

cuH,3cH,

I L. C. Vishwakarma, O. D. Stringer. arr 2F. A. Davis,S. G. Lal, andH. D. Durr

Nitrogendioxide,NrO.. N-Nitrosation.t N-Nitroso-and warmingto lactones.A reviewof thrs concludesthat the route via nitrord lactamsproceedsin almost quanttta CHrCl2at - 10".

f

C:6

(cH,)i -" xn \ \__-/

trzv.' " tn'*n', C, I , (iH.)| " e2-tffi%

I, n -- 4-14

\

\.

\_-/ !

I Y. H. Kim and D. C. Yoon. Tetrahedron Letters.29.6453(1988).

r N. Torra,F. Urpi, andJ. Vilarrasa.fa

o

tl

(1), m.p. 722' dec. peroxide,(p -OTNC.H.SOL p-Nitrobenzenesulfonyl

I Halogenationof arenes,r Chlorinationor brominationof arenescan be ef' fectedwith (C,H.).NHCI or (CrH5)3NHBrin CH.CN or CH,CI in the presenceof p- or r??-nitrobenzenesulfonyl peroxide.The effectivereagentsevidentlyaresulfonyl hvpohalites. C6H,CH3+(CrHr),NHCtf:#j-

+ (CrH,),NHBr C6H5OCH3 --

CIC6H4CH3 (plo= 58:42) p-BrCuHoOCH, (P/o= 100:0)

I M. Yoshida, (1988). andN. Kamigata, Chem.Letters,2017 H. Mochizuki, 13, 23. C.HsSOzN:CHCoHTNOT-p, N-(p-Nitrobenzylidene)benzenesulfonamide, Preparation.t Catalytic oxidation of R$ to R6S=O.' This sulfonamidecan function as a catalystfor oxidation of sulfidesselectivelyto sulfoxidesby Oxone@(potassium peroxymonosulfate). The net efiectinvolvestransferof oxygenfrom an N-sulfonyloxaziridineto the sulfide.This catalyticsystemis useful becausesulfonesare formed if at all only in traces.

l-Nitro-2-(phenylthio)ethylenc. C-H. Indolizines.2 The reagentreact of N(C:H.). to give the indolLrne dc formed.

R:.,A*-R

i l l Br-\*2 I

cH2cooc2H5

c

2,R=H,CH:

N. Ono,A. Kamimura, andA. Ka1..l : Y. Tominaga, Y. Ichihara, andA. Horr

( 1S,2R).Norephedrine, C6H.CH(OH Enantioselectivealkylation oI q, amountof the N,N-dibutylderiratirc of esterssuchas 3 or 4 to form (SH cvclizeto opticallyactivealkvl-sublt

(1S,2R)-Norephedrine 219 a ; rhosphodiesterbond to the 5'-

l.:.. ( him. Scand.8,,37, 857(1983). c r ( : . \ . v a n d e r M a r e la, n d J .H . v a n

r bypotassium superoxide s ,'rrdrzed ; .r.ndesto sulfoxides at -25" in

rL. C. Vishwakarma, O. D. Stringer,and F. A. Davis,Org. 9yn.,66,203(1987). ' F. A. Davis,S. G. Lal, and H. D. Durst,"/. Org.,53,5004(1988).

Nitrogendioxide,NrOr. N-Nitrosation.t N-Nitroso-and N-nitrolactamsare known to decomposeon warmingto lactones.A reviewof this methodfor conversionof lactamsto lactones concludesthat the route via nitrosolactamsis preferablebecausenitrosationof lactamsproceedsin almost quantitativeyield with NrO, and sodium acetatein CH2CI2at - 10".

ini.ulfones.'

o - \ ' i r l l -----_ --------rc6H5scH3

,€F"#*F,C::" c.t A

ft:o

-4(CH")1s-Bs% U

I, n = 4-14

|

+N=N+O

3

t ^ - : < .(r1 9 8 8 ) .

I N. Torra,F. Urpi,andJ. Vilarrasa, Tetrahedron,45. U63(1989). li. 1l l. m.p. 122o dec.

:: slnation of arenescan be ef{ ( \ (rr CH:CI2in the presenceof evidentlyaresulfonyl :t:r: r-.dgents

I l-Nitro-2-(phenylthio)ethylene, C.H.SCH:CHNO: (1). Preparation. Indolizines.' The reagentreactswith the pyridiniumsalts(2) in the presence of N(C.H.). to give the indolizinederivatives3 and 4. When R : CH., 4 is not formed.

R:-\zR L

-

clcuH.cH, : ' = 58:42) I-BTCoH.OCH: ,. o = 100:0)

t: ,.:::r'r-t. 2017(1988).

i l l B.\r{ry' cH2cooc2H5 2,R=H,CHr

c2H5o2c 4 (0-397o)

L N .O n o ,A . K a m i m u ra n, dA . K a j i ,J . O r g . , 5 1 , 2 1 3( 199 8 6 ) . :Y. Tominaga, Y. Ichihara, andA. Hosomi, (1988). Heterocycles,27,2345

.ll SO,N:CHC6HaNO1p, 13, 23. h:. -ulionamidecan functionas a su.:.,rrdesby Oxone@(potassium n-t.:: tri oxygenfrom an N-sultonc: t. useful becausesulfones are

(eryrhro) (1) . (l.S,2R)-Norepheilrine,C$,CH(OH)CH(CH)NH. Enantioselectivealkylation of a-formyl esters,t In the presenceof a catalytic amountof the N,N-dibutylderivative(2) of 1, dialkylzincsadd to the formyl group esters.Theseesters of esterssuch as 3 or 4 to form (S)-4-or -5-hydroxyalkanoic lactones. cyclizeto opticallyactivealkyl-substituted

(1S,2R)-NorePhedrine

o il

t" # nilcur;pooc2H5 + (cH3)2

H-c(cHr)rcooc2H5 HO

CH,

,rofo"-

Organoaluminumreagents. Review.r Use of these reagen (130references).

ff cu,z\oAo

1 K. Maruoka and H. Yamamolo. Terrc

S, 907o ee

o t" # + (crH5)2 HJ(cnr),coocH, 4

#

crg,AoAo S, 887oee

and K. Ebihara,chem'Letters'843(1988)' I K. Soai,S. Yokoyama,T. Hayasaka,

chiral. Organoboranes, of Synthesis Purc enantiortcrtobtainedfrom ( - F organoboranes opticallypure amines,halides.hrdt aldehydes,a-chiralacids.esters.nt ' H. C. BrownandB. Singaram. .{i(-'

OrganoceriumcomPounds. RCeClr. The reagents.Prepa than RLi in 1,2-additionto cartro (I ) alkoxypropionoyl-1,3-dithiane hen obtainseven'* tereoselectivity

R'e il-

CH.YS/ il

o I, Rr= SiMez-t-Bu cHrLi CH3CeCl,

{ 6

T. Imamoto,T. Kusumoto.\' Tarl J. Org.,49' 39Ol(lgttrt Yokoyama, rT. Sato,R. Kato, K. GokYu.and T

OrganocopPer reagents. Role of BF3'O(CrIItlt in rtr.' the beneficial effect of BF. ethen activation. Lipschutz et a/.' conclu Spectroscopicstudies of the efiect

HC CH.)rcooc2Hs \

O

,1i

CH, I

Organoaluminumreagents. Review,t Use of these reasentsin svnthesissince 1984has been reviewed (130references).

\,,4

I K. MaruokaandH. Yamamoto, Tetrahedron. 44.5001(1988).

9^; ee

I

4

|

c,u,

|

oAo S, 887oee

r:

, , : r ' f n .L e t t e r s ,8 4 3 ( 1 9 8 8 ) .

Organoboranes, chiral. Synthesis of purc enantiomers. Brown and Singaramrhavereviewedthe chiral organoboranes obtainedfrom ( + )- and ( - )-pineneand their usefor synthesisof opticallypure amines,halides,hydrocarbons, lithiumalkylborohydrides, ketones, aldehydes, a-chiralacids,esters,nitriles,alkynes,and alkenes. 1H. C. BrownandB. Singaram, (1988). Acct.Chem.Res.,21,287 Organoceriumcompounds. RCeClr. The reagents,preparedin situfromRLi + CeCl.,raremore reactive than RLi in 1,2-additionto carbonylgroups.An exampleis the reactionwith 2(1), preparedfrom methyl(S)-lactate.' The alkoxypropionoyl-1,3-dithianes diastereoselectivity obtainsevenwhen the protectinggroup is incapableof chelation.

Rro $a i I

*'"

+

l---+

anti-2

CH,YS/ o 2 (syn)

l, Rt= SiMez-t-Bu cH3Li CH.CeCl,

407o l ll"/o

80:20 94:6

'T. Imamoto, andM. T. Kusumoto, Y. Tawarayama, Y. Sugiura, T. Mita,Y. Hatanaka, Y o k o y a ml a . ,O r g . , 4 9 , 3 9 0( 149 8 4 ) . I T. Sato,R. Kato,K. Gokyu,andT. Fujisawa, (1988). Tetrahedron Letters,29,3955 Organocopperreagents. Role of BF;O(CrIIr), in reactionsof R2CuLi.t It is generallyacceptedthat the beneficialeffect of BF. etherateon cupratereactionsresultsfrom substrate activation.Lipschutzet al.l concludethat BF. etheratealso modifiesthe cuprate. studiesof the effectof BF. etherateon (CHj)rCuLi indicatethat the Spectroscopic 221

2?f2

OrganocoPPerreagenrs

into a mixture of four components: Lewis acid converts the homocuprate is more cH3Li'BF ' and BF'' In general'(cH')'cu'Li fttH,lcrr-il2, (cH.):curli, then 2 CuI' 2 + CH'Li 3 preformedfrom reactivethan (CHJ:Cut-i, unA can be about to etherate BF' with (CH:):CuLi BF.. It can alsoU" g"nt'uttO by warming L0' beforeaddition of the substrate' more thermallystableand alsomore RCuIS(CH)2. Variousalkylcoppersare reactiveindimethylsulfidethaninetherortetrahydrofuran.Thissolventcan in alkylationof acid chlorides'l improveyieldsin .oniugut" additionsand reductionof the Cul-triCoupling with ROil: The lithium naphthalenide activeCu(0)' This speciesreactswith phenylphosphln..ompt"x resultsin a highly to reagentthat reactswith acid chlorides alkyl bromidesto give an alkylcopper nitriles, esters' as such functionalgroups furnish ketones.This synthesi,tot"iut", canbe a competingreactionwhen Homocoupring haride,and evensomeepoxides. than bromidesand with phosphinesother alkyl iodidesare used in place of the

o cl(CH2LMTB' CUB!.S(CHIl BF,.O(C,H
,\

l\NAA,r l

56%

/ i 1 \

COOBz r, Ar = CJL(OCH3)2'3'4

P(C6Hs),.

l) Cu(0)

-*2)c^H<99!5c6H5co(cH2)3cooc2H5 CTH'OOC(CH)rBr

o-

.zo:.

cr{-}ntCH,)uBr

CH' --- -+ C6H5CO(CHJ6CFi

1,6-Addition to an enYnonclll.' undergo1,6-additionto 1 to provide t tno product. The (Z)-stereoselectivitl' group. The addition may involve an al ever, provides(E)-dienones,possiblrr

chiral cyclicketalsare cleavedby Cleavageof ketals(I2,347. 348)' Certain to chiral secondaryalcohols'a RrCuLi/Bf",'OiCrHr), diastereoselectively

"o----]-7 t

P----.-l

l

/.H^L.ilriRF,.o(crH
c,a, po -flcn,iesX#.% in,, r\

c 6H5 t", ". qH,t('o--l-J C", (9lVo de)

o II CHr-
^r

/ + r-Bu,C

I

l of the Lythsynthesis stereocontrolled Coniugateaddition's The key stepin a additionof an alkylcoppercomplexed raceaealkaloidlasubinelI (4) is the coniugut" 1 to give the cis-product^2in56Vo with BF. to the N-acyl-z"S)dihyO'o-+-pytiOon" in the presenceof Li'CO' effects yield and )96Vo stercos"i"tii"i'y' Hyirogenation to give the ketone 3' which is reduced cyclizationand deprotectionof nitrogen to the desiredalcohol4' by lithium trisiamylborohydride stereoselectively

1.3-Dienes.1 A new route to (E.i vlcuprateswith crs- or t/4ns-epoxl-sil re erythro-or threo-$-hydroxysilanes. t b1 (Z,Z)-1,3-dienes (Z,E)or either

OrglnocopFt

) .: :1lr\!ur€of four components: is more Bt ln seneral.(CH,).Cu2Li then 2 2 CuI, + tr.c.:lr()m -i CH,Li about to etherate ll t uli \rith BF. :: lhcrmallvstableandalsomore This solventcan f , : , :;.!h\drofuran. 3 . r . ..,trorof acidchlorides'2 of the Cul-triPt.: .:nide reduction reactswith ('u((|). This sPecies & . 1 . r: to chlorides acid r.:i reactswith nitriles, esters, ,. *roupssuchas i n i - .rnbc a comPetingreactionwhen other than .rn.lxith PhosPhines l.l:. ii:

o -J|-t l t

:'"'SXlili,** ,) ,\

BF..O(CrH<), ----:+

\*A*

56%

n3

o

CI

l

tt StrB

I

|

|

|

|

|

9*Ao, COOBz

COOBz I, Ar = C6H4(OCHJr-3,4

2 (cis,>961oen) | 9", pa/c

B2qoI L;co1

H

, ) in*,Jllno",,,,n l------J4---J*---,*,--'-----=JK"

C..lrCOrCH,),COOC2H'

1,6-Additiontoanenynone(l).6Cuprates,particularlyhigher-orderones' to 1to providethe lessstable(Z)-dienone2 as the major undergo1,6-addition increaseswith the bulk of the transferredR product. The (Z)-stereoselectivity an group.The additionmay involve allenylenol' Addition of CoH'SLito l'' howeue., prouides(E)-dienones,possiblyvia an intermediate1'2-adduct'

,,-o:. -CHt

' Cll:)oCH

tt'

1:' ,ltliil c;-clicketals are cleaved by r ' . ' : . ' l . c c t r n d a r ya l c o h o l s ' a

o

^oH o

.

CHr-.A., \ ,/-

CoHr..._--o__{- LcH,

cu,t

C", (91Vode)

I

H I

il

/ + r-BurCu(CN)Li,93% H

Bu-r

2 (ZlE= 34:l)

of the Lythsynthesis I ' : .-:r\)controlled complexed of an alkylcopper , [ r . :.:.rr(ion I ttr sive the cls-product2in56Vo of LizCO.effects rn the Presence .,,:r l'l; I is reduced which 3, ketone the c .:.\c 4' alcohol desired the ro ! . r : :.ic h ^ :.

1,3-Dienes.lAnewrouteto(E,Z)-1,3-dienesinvolvesreactionof(Z)-alkenin the presenceof BF3 etherateto give ylcuprateswith crs-or trans-epoxysilanes respectively.Theseproductsare convertedto ,ryiro- or threo-p-hydroxysilanes, by basicor acidiceliminationof (cH.).sioH. either(Z,E)- or (z,z)-1,3-dienes

Organocopperresgents

"...4...n

BF3,e0ter

*

1c",;rs,n".p,rt (z)-r

,0. ........_

crrr'-)rcoLi

o Bzlo ..'\ "*P

o

H Bdo-.21_

t

OH 1...H (CH3LSi/l \Heptyl czHfz H...

3 C"H. "',\'^H.pryl

**

.

3

s2% frcm I

c"u.fl:.

r* | rcx,
Heptyl

+

(Z,E > 97Vo) H..

n. f1 ..Pentyt +2 'H (cH3)3si'

-

NaH

<-5 65% from 4

BF:.c(czHsh,crHr/:\:/P"ntYl 70% (Z,Z > 977o) from 4

,(' '

o sff-'

I

Vinyllithiums (cf. 13, t421.. A couplingof vinyl and aryl triflaresrrri formula (R,Sn),Cu(CN)Li,.prepared -50o to -60". The higher-order cup - 20oto providea vinyltin intermedia providesa vinyltin, with brominea rir

Reaction with p-propiolactones.t Theselactonesare cleavedto 3-substituted propionicacidsby a numberof organocopperreagentsincludingRrCuMgX, R.CuLi, RzCu(CN)Liz,RCu'Bu,P.The reactioninvolvesselectivecleavageof the B-carbonoxygenbond. \

R2CuLi,

oH

CH.

c2H5-_z

Pentvl

(Z,E> 977o)

osiR3oH BzlO_...LzL,,1

(cHJ3Si

(E)-4

Cr,t\:r/

: CH,

BF3.qC2H5b,

50% frcm I

(z,z > 97%)

osiR3oH nzfo-.r\_,i_,{

orf ,\

t

\./

I) @u3sn)2CffrL2 2) ArOAc - l 91%

l

/ I \

Benzylic organocopper rcatcrc,

(

Zn@rcH2cH2Br\

I

R(cH,),cooH T

(111, Polypropionate1,3-diols.e The method for synthesisof syn-1,3-polyols 139)of the polyacetatetype has beenextendedto polypropionatesmerely by use of an (E)- or (Z)-propenylcuprate,(CH.CH:CH),Cu(CN)Li (1), in place of a vinvlcuorate.

1r)crH,iHBrd.$-.--

cJ..r

(R = H, CH3)

Theseorganocopperreagents(equan hydes,acidchlorides,enones,allvlicb

Organocopperreagents BF, r::*

o Bzlo ..'\ r# H...

,--1 / (CH3)3Si |

o

OSiR3

l) vo(&rch

H Bzlo-rzL,.1r.CH,

2"-F

Bzlo-r''L''{i'

c2H5-z

3

osiR3 oH .o BzlO...,,,L,,1-.{j.C\

E

osiR3oH BzlO-r,,1r\-.,1r,CH, CH,

CH,

L.

t - :...

t:\:a

.

er* | tcq=cxl,corcnylq

Heptyl

(Z'E > 97Vo)

OH Pentvl

*

osiR3oH oH Bzlo-r2L,\-,\zCH:CHz CH, CH,

H

t ,, /:\:/

f -

r.l

urolcl-r *

OH 1...H 'Heptyl

225

.PentYl

! . I l <

(Z,Z > 974o)

Vinyllithiums (cf, 13, 142).10An improved route to vinyllithiumsinvolves of the couplingof vinyl and aryl triflateswith tributyl- or trimethylstannylcuprates formula (R,Sn)zCu(CN)Li, preparedfrom LDA, R.SnH, and CuCN in THF at -50'to -60". The higher-ordercupratescouplewith vinyl and aryl triflatesat - 20'to providea vinyltinintermediate. with AgOAc Work-upof the intermediate providesa vinyltin, with bromine a vinyl bromide,or with CF.COOH an aryltin.

orf

l:,i,,:t€sarecleavedto 3-substituted !ri: :.r!\includingRrCuMgX' RrCuLi, ofthe B-carbonF. .:.rctivecleavage

,\

t

l

\-,/

1) (Bu3SnbcucNLi2 2) AgOAc ) 97qo

+ RSnBu,

B enzyI ic organocopper rcagents, CoIIsCH zCu(CN Z nB r (l).

Preparation:

cri cooH R I

Zn(BrCH2CH2Br),

(l) CTHTCHBT #* (1lZ' I i,.: .inthesisof syn-1,3-polyols use by merely lgJ :., polypropionates of a place (l), in l:( lI).cu(cN)Li,

(R = H, CH3)

R I

C.H,CFZnBT

CuCN.2LiCl,

rHF'-20' t

R I

curtrcHculcNlznnr I

Theseorganocopperreagents(equationI) react with variouselectrophiles,aldehydes,acidchlorides,enones,allylicbromides,in 85-95Voyield."

cH'

OrganocoPPer reagents

t26

Alky lbis(t-butylphosphidolcttpnata. I obtainedby reactionof RLi with [CuP(tin THF at 25ofor 4 hours,but can be usc ment (particularlyof primary halides).an a-Alkoxyorganocuptates.t5 c-Alkor shown,provide a novel synthesisof tetra

CI CH'Cu(CN)ZnBr + CHr:fllgHzBr

CH,CH'CH:CH, -+ CI

CI

t#4

+ rcHo C.H,CHrcu(cN)ZnBr

c6n5cHrc.tpr OH

tl

|

|

\,,'

t-a\ /'V'cH'cu(cN)znBr + ll ll |

?C Y

cH2cc6H5

+cuH'cocr-------+

ll

I

\./

o tl

(CN)ZnBr

.--\)-\Z'\/CH'Cu

N

8

4O

crsi(cH,)1(car) AYY) t------?l ll

q

C

A

YN

ll

Y

r

O

tH3-Li-o-

3(CH,)rCuLi+ HrO ------+ZCH.+CHrCu+ Cu

t" cH3-Li-cH3 I

asl,andapolymericmethylcopper.Thisnewreagentundergoesrapidanddiasadditionto enones. tereoselective

ll

t

l-t*i-

+ 1 6 :I

l,,Io"orlx&n, "u c.nf

c' si(cHrlr,

O*,

J

,.Li

cuH'.-/Y/\c.g. -'. H' OMOM

l- gsircH,

?

preparedfrom (CH)3SiLi Lithium bis(trimethytsilyl)cuprate'D This cuprate' in moderateto high yield' and CuCN, convertsacyl chioridis into acylsilanes traces of water' lithium Methyloxidocopperlithium (l)'t! In the presenceof tentativelyformulated dimethylcuprateis convertedinto a bright yellow reagent'

o

,OCH"OCH" - r, a.r, ' 2)crc\ -,4-(cH3)rcHCH 'SnBu,

cH(

L

2 in the presenceof TMSCI givesa srng uith TiCL at -78'cyclizesto a crs-fuse at thc can alsoshow diastereoselectivit-v nng. when comtrn c-Alkoxyorganocuprates to preferential1,4-addition c,p-enals r s .elective(45-250:1).The 1,2-addition OMOM

gu\

I

t2

+ euA'/cHo cu(cN)Li, -

j

oMov t t

B,Y

OH (r.2-d l7{

Organocopperreagents

Alkylhis(t-butylphosphido)cuprates,RCuP(t-Bu){,i.ta These cuprates are obtainedby reactionof RLi with [CuP(t-Bu)la.The cupratesare generallystable in THF at 25ofor 4 hours,but can be usedfor conjugateaddition,halidedisplacement (particularlyof primary halides),and epoxidecleavage. a-Alkoxyorganocuprates.tsct-Alkoxyorganocuprates suchas 1, preparedas shown,provide a novel synthesisof tetrahydrofurans.Thus conjugateadditionto

I \_.,.cH.cHrcH:CHz Act H}: t!

rlnur-i,

(cH3)rcHdH 'SnBu,

o tl

f

MoMo "'-- -t I

I | 2)cucN, cutcNyr-t, [cu,l,cHcHlrJ I

,OCHTOCH,

cH2cc6H5

o

ll

I

-l-

77%

H cH(cH3)2 3 (69:31) H '^

a

Yo

('\

preparedfrom (CH3),SiLi 5 . --:'r.rte. to high Yield' moderate rn Ji'.:. of water,lithium traces of p:J-r:rce formulated ; tentatively :c.rgent, Jl. I i

C H .- L i - o /

I Cu Cu I -Li-cH3 I I

l { i - -

Ticl{ CH2C12, ----{

l l +l l

w.'

CH,

I

2 in the presence of TMSCI givesa singlesilylenol ether(a), whichon treatment with TiCl. at -78'cyclizes to a crs-fusedannelatedtetrahydrofuran.The reaction can also show diastereoselectivity at the exocyclicpositionof the tetrahydrofuran ring. cr-Alkoxyorganocuprates whencombinedwith chlorotrimethylsilane alsoundergo preferential1,4-additionto c,B-enals.Of greaterinterest,the additionis syn(45-250:1).The 1,2-addition selective showsno diastereoselectivity.16 QMOM .A. r Bu- )^Cu(CN)Li,+ Br',1./CHO

cls(cHl)r

rsr, -re-io',

r:.r{cnt undergoesrapid and dias-

OMOM

OMOM

,"Ftu I

/27

*

u"\1."o Bu

OH ( 1,2-adduct, 17Vo)

syn-l (30Vo) ' r- *- 1| t2) x) cr or *o l

o

tl

to

,-cli 'c.ll.

+ 1 6 I:

MOMO CuHi

I

BuflBu (crr)

I

rrl,tanti-r

nE

Organocopper reagents

Dilithium(timethylstannyll(2-thienyllcyanocuprate, (CH.):SnCu(2-Th)CNLi, (1)r?.The cuprateis preparedby addition of CH.Li (2 equiv.) in ether to a THF solutionof [(CH).Sn], (1 equiv.) and thiophene(1 equiv.); the reagentis formed after additionof CuCN (1 equiv.). The reagenttransfersthe trimethyltin group to the B-positionof a variety of esters,includingacetylenicesters.It is generallysuperiorto the cr,$-unsaturated lower-ordercuprate[(CHJ.SnCuSC6H,]Li(10, 289).

--r. THF. ,*-

CH,

orf.

CH". \_^

E

tB.!' -r _\) _ 6:-r

/

C.Hi

o

-20'

CH,

CH,

RCU-ISi(CH)s.n This reagen agentfor 1,4-addition to enones.(Zf

cH't

CH,

CH,

Sn(CHr),

,\

."4y't U"*ooc2H5,'OdJ::'*'u' CH.

t "

(cH3)3cliocHrc-c-coocrH' .-.--> I &siocH2 CH,

r

95:5

Z-3 (65Vo)

)

2

H

l) r HMPT 2)CHll, ' > 65%

(CH:)rSna__-COOC2H5 cH,

R3SiocH2 4

(r)." rhis cucopperlli thium, (\"",.*,r, 12-Th i enyI (cyano'1 -18 ---> prate is preparedby reactionof 2-lithiothiophenewith cucN in THF at -40.. It is relatively stable, but can be convertedto higher-ordercupratesby reactionwith RLi or RMgX at - 78".Thus reactionof 1 with vinyllithiumprovides (cH,:cHx2-thienyl)cu(cN)Li,(2), whichismoreusetuIthan(cH,:gH)cu(cN)Li for cleavageof epoxidesand for conjugateadditionto enones'1"

F

,CHtOBzl

* 2 +#

CH,:CHCH,CHCH,OBzI OH

CHt

CH;

+zfi-

B. H. Lipshutz,E. L. Ellswonh.and T : S. H. Bertz and G. Dabbagh, Tetrahcd ' R. M. Wehmeyerand R. D. Rike. Icrr 'J. F. Normant, A. Alexakis,A. Ghnh. i 'J. D . B r o w n ,M . A . F o l e y ,a n d D . L C ' M. Hulce, TetrahedronLetters.t). S?y< A. Alexakisand D. Jachiet,Tetrahedra ' M. Kawashima,T. Sato,and T. Fu.;isar B. H. LipshutzandJ. C. Barron..1.Orr S. R. Gilbertson,C. A. Challener.Il E 1795(l988). S. C. Berk, P. Knochel,and M. C. p li :A. Capperucci, A. Degl'Innocenri. C t ors., 53, 3612(1988). 'E. J. Corey,F. J. Hannon,and N. \,\' I ' S. F. Martin, J. R. Fishpaugh.J. t\t por and A. H. Cowley,Am. Soc..ffO. -:J6 ' R. J. Lindermanand A. Godfrey-.rbd . ' R. J. Lindermanand J. R. McKenzr. I E. Piersand R. D. Tillyer, J. Org.. 53. I '8. H. Lipshutz,M. Koerner,and D. .{. 'B. H. Lipshutz,R. Moretti,and R. Cro : M. Bergdahl,E.-L. Lindstedt, M. :\ibso

cu,

CH:CHz

CH;

CH,

Organocopper/Zinc reagents, RCu(C )ubstituted by a chloride, ester, or enoi *ith CuCN and LiCl (2 equiv.)., Tb enones,even B,B-disubstitutedones. u r e q u a t i o nI ) . 2

Organocopper/Zincresgents

tontcupmte, (CH.),SnCu(2-Th)CNLit o: r ll Li (2 equiv.)in etherto a THF tt:'rr r I equiv.);the reagentis formed p -.:' lrr the p-positionof a variety of r ..:Jr\. It is generallysuperiorto the rlll lr9).

/29

RCU-ISi(CH)yn This reagent,when solubilizedin PBu, is an excellentreagentfor 1,4-additionto enones.(Z)-Silyl enol ethersare formed preferentially. cH3cu,Isi(cH3b "Fo#5.",,

OSi(CH.)"

CH,.

)7-ci,.n-r

t coHi

5:l

c.H; z-l

* , i i ,

o

CH, Sn(CHr),

t ll,

a\

."p

a----a,Sn(CH),

I

Sn.

r( ii

R . x--ll.

,COOCzHs H

+ E-3

95:5

Z-3 (65Va) I

cooc2H5

ll.

cH, l

(

t It lc

7

Y)%

t

rAl

l

cH|/"cH3 (translcis = 5:l)

l-t"zcooc2H5

_

osi(cH3)3

'-cu(cN)Li (l)." This cu. - - ' r r n i t h C u C Ni n T H F a t - 1 8 ' - - > . -:tcd tt'rhigher-ordercupratesby -: ,'n of I with vinyllithiumprovides -, uretuIthan(cH,:gH;6u(CN)Li . . : : r ( \ nt o e n o n e s . l ' r

r B . H . L i p s h u t z , E L. . E l l s w o r t ha, n dT . J . S i a h a a nA,m . S o c . , 1 f 1 ,1 3 5 1( 1 9 8 9 ) , r S. H. Bertz and G. Dabbagh,Tetahedron,45, 425 (1989). 'R. M. Wehmeyerand R. D. Rike, TetahedronLeuers,29,45l3(1988). 'J. F. Normant,A. Alexakis,A. Ghribi,and P. Mangeney,Tetrahedron,45, 507(1989). j J. D. Brown, M. A. Foley,and D. L. Comins,Am. Soc.,110,7445(1988). ^ M. Hulce, Tetrahedron (1988). Letters,29,5851 ' A. Alexakisand D. Jachiet,Tetrahedron,45, 381(1989). 'M. Kawashima, T. Sato,and T. Fujisawa,Tetrahedron,45, 403(1989). 'B. H. Lipshuta z n dJ . C . B a r t o n l,. O r g . , 5 3 , 4 4 9 5( 1 9 8 8 ) . "'S. R. Gilbertson,C. A. Challener,M. E. Bos, and W. D. tVulfr,Tetrahedron Letters,29, 4795(1988). " S. C. Berk, P. Knochel,and M. C. P. Yeh, J. Org..53,5739(1983). r: A. Capperucci, A. Degl'Innocenti, C. Faggi,P. Dembech,G. Seconi,and A. Ricci,,/. O r g . ,5 3 , 3 6 1 2( 1 9 8 8 ) . 13E. J. Corey,F. J. Hannon,and N. W. Boaz,Tetrahedron,45,545 (1989). 'S. F. Martin,J. R. Fishpaugh, J. M. Power,D. M. Giolando,R. A. Jones,C. M. Nunn, and A. H. Cowley,Am. Soc.,ll0,7226 (1988). 15R. J. Lindermanand A. Godfrey,ibid.,ll0,6249 (1988). 16R. J. Lindermanand J. R. McKenzie,Tetrahedron (1988). Leuers,29,3911 17E. Piersand R. D. Tillyer,.I. Org.,53,5366(1988). l'B. H. Lipshutz,M. Koerner,and D. A. Parker,Tetrahedron (1987). Leuers,2E,945 l'B. H. Lipshutz,R. Moretti,and R. Crow, Org. Syn.,submitted(1988). r"M. Bergdahl,E.-L. Lindstedt,M. Nilsson,andT. Olsson,Tetrahedron,45,535 (1989).

il :CHCHzCHCHTOBzI I

OH

{,,

Il. i ll

CH:CHz CH,

Organocopper/Zinc reagents, RCu(CN)ZnL These reagents, in which R can be substituted by a chloride, ester, or enoate group, are prepared by reaction of RZnI with CuCN and LiCl (2 equiv.).r These reagents undergo l,4-addition to o,Benones,even B,B-disubstitutedones, in high yield when activatedby BF. etherate (equation I).'

Organolithium reogents

!"'

o

ll

A

0)l

\AI

Cl(CHzLCu(CN)ZnI THF, -30'

ll

E4%

Pl"o-iH(cnrbcu(cN)z^ttI -13+r BF:'O(CzHsh' r 86%

, (cHr)4cl

CH"

t -

(cHr)rcHOPiv (cHr)4cl such as 1 can be bicyclic difluoroboron enolate In some casesan intermediate a bicyclic ketone '"uttion and converted into 'solated from the BF'-p;;;;; (equationII)'

o il

or)fi

F-..

,F

dt*

r l BFr'o(czHsh ' + rZn(cN)cu(cH)3cN82qo -n \r+-./

\,^cH3

l

CH, t .

*Htg

r

o

H

proceedsin 90-99% yield at -45" with and vinyllithiumsfail to add to 1. Howev in situ ftom the correspondingtetrasubsu addition also in high yield. The reactivc r and CH.Li, or it may be nonaggregated prc are reagents RoSn also is helpful. The of Mg with RCI in THF to form RMgCl. M agnesium2-ethory ethoxide, M glOC the activityof RL alkoxide(L) decreases be preparedin THF in the presenceof 0 ce are that someunstableorganolithiurqs supp'r be directed ortho-metallationcan (D ialkoxy methYI) I i thi um, (ROI{, n this type havebeenpreparedby lithiatio metalationof (RO),CHSnBurat I ltr' -95', but cycliconesare relativell st at this type are shownfor the lithiodiorar electrophilesto give acetals.It forms ll

o o.

,\

I''.(,

(1988)' Talbert'l' org'' 53' 2390 ,p. Knochel,M. c. P.Yeh,s. c B9'I'^il9 J' 29' 6693(1988)' "d^,,-iririn"dron Letters' dihyOrganolithium 'Generationt:"C":tt; (12' 310-311) of 1,1,2-trisubstituted in situ't A synthesis 1the to of alkyllithiums as the first step addition (2) products dronaphthalenes(3) involves The lv t'"ppi"c.w:th';n electrophile' of RLi naphthyloxazorin"r toill*"i l"quaiion I)' Addition can be convertedto tormyl-l'2-iihydronaphthalenes

(I) 2 (>100:l)

L+CuI.PBur*2

h'

yield.The derivedcopperreagentwheni by conjugateaddition. Unlike most or reactwith alkyl halides,often in high y (a-H aloalkenYl) I i th iums, |X rc n ) (t halo-f -iodo-1-trimethylsilyl-l-alkene (2) in 65-&s beredcycloalkenylsilanes groupis not essentialfor the cyclizauon crs-relationshipbetween Li and the r,> Cyclizationis alsopossiblewith (ro-b is Al. Zn, Zr, or Si' In this cyclizatio

Orgonolithiumreagents CHr

t -

PivG{H(CHz}:Cu(CN)ZnI B F " ' O ( C r H < h- ,1 3 + 0 ' 86%

{-,.c1 CH"

t -

(cH),cHoPiv (CHJ4Cl h\r{,boron enolate such as L can be J c,rnverted into a bicyclic ketone

F

F

/.8... O N NaOCHr, CHrOH _-.------:-.-1 7t%

231

proceedsin 9\-ggvo yield at -45'with n-, sec-,and r-Buli, but alryl-,benzyl-, and vinyllithiumsfail to add to 1. However,these organorithiums when generated in,situfrom the correspondingtetrasubstituted stannanewith cH.Li, undergothis addition also in high yield. The reactivespecies may be an ate complexof R.Sn and cH.Li, or it may be nonaggregated reagent.In somecasesadditionof HMpr alsois helpful.The RrSnreagentsare preparedin about 70-90voyierdby reaction of Mg with RCt in THF to form RMgcl, which is then addedto snct. in benzene. Magnesium2-ethoxyethoxide, Mg(OCHTCHTOC{Is)r. preparation.3 ., This metal alkoxide(1) decreases the activityof RLi reagentsto suchan extentthat they can be preparedin THF in the presenceof 0.5 equiu. of 1. The advantages of this fact are that someunstabreorganorithiums can begeneratedby this techiique and that directedortho-metallation can be suppressed if desired., (Dialkoxymethyr)rithium,(Ro)rcHLi.s Both cyclic and acyclicreagentsof this type have beenpreparedby lithiation of (RO),CHSC.H, _ at 95. or by rransmetalationof (Ro)rcHSnBu. at -r10". The acycricreagents decompose rapidry at -95', but cycriconesare relativelystabreat -45 to -7g". Typicalreactionsof this type are shownfor the lithiodioxanereagent 1, which reactswith a numberof electrophilesto give acetals.It forms r,2-adducts with ketonesand enonesin hieh

ci''. I Or9.,53,2390(1988). N<':'.

l+CuI.pB * 2uJ, o { w \ A tr- i i I ) of 1,1,2-trisubstituteddihya.lirtion of alkyllithiums to the 1h J1 clectrophile. The products (2) rlc:c. (equation I). Addition of RLi

\CH, ' C H , :1

a.

i-o) o

l \--l

vield'The derivedcopperreagentwhenactivatedby BF. etheratereactswith enones by conjugateaddition. Unlike most organorithium reagents,thesenew reagents reactwith alkyl halides,often in high yield in the caseof primary bromides. (a-Haroarkenyr)rithiums, IX(cH),cR:czlLi.6 The I/Li exchangeof ohalo-1-iodo-1-trimethylsilyl-1-alkenes (1) with BuLi resultsin three-to seven_memberedcycloalkenylsilanes (2) in 65-g5voyield. The presenceof the trimethyrsilyl groupis not essentialfor the cyclization,but facilitates isomerization to the required crs-relationship betweenLi and the <,r_halo alkyl group for cyclization. cyclizationis alsopossiblewith (co-halo-1-silyl-1-alkyr)metals in whichthe metal is Al' Zn, Zr, or Si. In this cycrizationa silyl group is essential.In this reacrlon,

A2

reagents Organomagnesiurn/zinc

*-":".ri(cH3)3 "\t x(cHr)"/"

u"5

*Hti(cHr), CH, :

(.a""r]

l,n=2,R=H n=4,R=CHr

(cH,)y'r]-X(CH"),--'.)c:c: ctzrcpr, |

L

cH{

[l

clsn(cH3)3 -

o

fa",

I

I

sn(CHr\ j

c.H,,- Y" -znBr

-Si(CH.)J

t

-ettcu,lI l

(I) BTZnCHTCH:CHOCzHT+ CrH.rC 4

tzl

/'si(cH3)3 r)crs(cH3b ar"ro_^a".

Si(CH") CH" vrr3><sr\vrr3/3

-

+

|

56qo

(:*)+r Ct"ztCP", Br(cHr)oc-csi(cH2)3 tj

CH

807o 70%

ezu" lzs" cH3 .

+ CuH,rCH:

(zlE = tt'

cyclizationto three- and four-memberedrings is more facile than that to five- or six-memberedrings.

x(cH2)rc-csi(cH3L

gggllrZnBr

.\ -cHo cuH,,,."

f"' + cH2:cH(cHr)rc:cHSi(cH,), (20*259o)

5 rtt:

(537o)

rA. I. Meyers,K. A. Lutomski,and D. Laucher,Tetrahedron' 44' 3107(1988)' ' D. Seyferthand M. A. Weiner,Am. Soc.'83' 3583(1961). 3 C. G. Screttas Chem.,290'(1985)' Organometal. and M. J. Micha-Screttas,J. a C. G. Screttas and B. R. Steele,J. Org.,54' 1013(1989). s C. S. Shiner,T. Tsunoda,B. A. Goodman,S. Ingham'S. Lee' and P. E' Vorndam'Am' S o c . . 1 l l ,1 3 8 1( 1 9 8 9 ) . 6 E. Negishi,L. D. Boardman,H. Sawada,V. Bagheri,A. T. Stoll,J' M' Tour' and C' L' Rand.An. Soc..110.5383(1988).

Organomagnesium/zinc reagents. These reagents can be obtained by reaction of vinyl Grignard reagents with allylic zinc bromides in THF at - 35 to 0o. Reaction of I with ClSn(CH:)r provides an o-trimethyltin-zinc reagent (2) that is oxidized by air to an aldehyde or ketone

This mild oxidationof diorganomer amines.rThus conversionof a pnmar) ( salt followed by air-oxidation( - 6Oro NHSi(CH3)r : I B.a-

v"-. l

l

l

,

Q

TNHCH,Si(CHJ -

(3).' This sequencecan be usedto obtain B-alkoxyaldehydeswith high stereoselecbromide (4) (6, 607), equation(I).' The reactionintivity from 3-ethoxyallylzinc of the vinyl Grignardreagent volvesalmostcompletetransferof the stereochemistry 5. the aldehyde to

P. Knochel and J. F. Normant. Tetrahedru P K n o c h e l , C . X i a o , a n d M . C . P Y c . h .r b l{. G. Chen and P. Knochel. ibtd.. tt. 6T

Organomagnesium/zinc reagents

233

Si(CH,),

)< t'(cHr)jl

CHz:CHCHz ZnBT+CuH,rCH:CHMgBr ----+ (Z/E = 88:t2)

,

faO C.U,.\MBB' '-ZnBr I

r::ri. r\ more facilethan that to five- or

crsn(cH3)3

fc""

._ ' - ' ..- e rstirc c HHr ,! ll

fcn,

o, ------)

I cuH,r\sn(cH')' -ZnBr

8t% overall

I

Acuo CoHt,

,

(I) BTZnCHTCH:CHOCTH, + CoH,rCH:CHMgBr --* a 1Z/E=88:r2)

t - .

-SrtCH.).

lC:': '

"nOJ^"n CuH,r\Mt"t ZnBr (translcis = gg:12)

CH.

I

- CH,:CH(CH')rC:CHSi(CHr),

crHrofcH, l)clsn(cH3b =:| coH,r"'\cHo

(20-25Ea)

',.thedron. 44. 3107( 1988). t,' 0 , ' -: l e 6 l) . ( , . . . ..1.'tul.Chem.,290,(1985). : . e \ 9) .

crHrof"n, -+ | cuH,rAcHo 5 ( 8 8 1: 2 )

This mild oxidationof diorganometailics has been appliedto oxidationof silylamines'rThusconversion of a primaryor secondary sirylamine to a lithiumor zinc saltfollowedby air-oxidation (-60 to -20") providesan ardehyde or kerone.

s . -..:m. - S. Lee, and P. E. Vorndam,.4m. NHSi(CH3)3 ;:r. .{. T. Stoll,J. M. Tour, and C. L. I ) BuLi

|

|

\-J E;.i 1 of vinyl Grignardreagentswith . i{: :,iror of I with ClSn(CH,)3 provides cr.:.:cd bv air to an aldehydeor ketone Fd.r \\ aldehydes with high stereoselecr 6 ^ , , - ) .e q u a t i o n( I ) . ' T h e r e a c t i o ni n R\\:.: mlstrvof the vinyl Grignardreagent

2)o,

i;7

;NHCH,Si(CH,),

A

| \./

|

A

f"o

------------)l

I

\_/

P KnochelandJ. F. Normanr,Tetrahedron Letters,27,1039 (19g6) P K_nochel, C. Xiao,andM. C. p.yeh,ibid.,zi,-iisl OSAsl. tl. G. Chenandp Knochet, ibid.,29,670t (i988).

234

rergents Organomanganese

Organomanganese(Il)halides' An attractive route to synthesisof unsymmetrical sec-and teil-alcohols.r RMnBr followedby reaction thesealcoholsinvorvesa one-potacylation(L3,210)of generallyhigher than that with an alkyllithium (14, zig). The overall yield is obtainedbyreactionofthealkyllithiumwiththeisolated,intermediateketone. homoallylicmanganese An exampleis the synthesisof a-bisabolol(2) from the bromidel.TheseRMnBrreagentscanbepreparedfromRLiusingMnBrz,which

stitutedindenolsin 60-75Voyield. Reactio in 2-trimethylsilyl-3-alkylindenols. The rc metricalinternalalkynesis determinedbv I to the 2-positiorl.Reactionswith etho4 ethoxycarbonylsubstitutedindenolsregar kyne. P entacarbonyI ( tri methyIsi ly l) nongra'

,,.",-S.o., t"2<2: t

2) CH3Li

(CHr)rC:CH(CHr)tMnBr

\'

1

t

(CHJ3SiOTf+ NaMn(CO)

l

\z-cH,

cH,n cH,

Although MnBrz is insolubleas is commerciallyavailableand cheaperthan MnI'' suchinether,itdissolvesinthissolventinthepresenceofLiBr'formedinsituon reactionwith an alkyllithiumreagent' 3659(1988)' Letters'29' rG. cahiez,J. Rivas-Enterrios, andP. Clery,Tetrahedron reagents' Organomanganese BzlMn(CO)s (I); indenols't Aryl ketones Benzylmanganesepentacarbonyl, (2), whichafter to form a manganacycle reactwith r selectivelyatthe ortho-position into a product converted is CH'CN in (Ci{,)rNO oxidativedecarbonylationwith with alkynesto form substituted1-alkyl-1H-inden(a) that reactsregioselectively a terminal alkyne reactsto form 2-sub/-ols (3). This reactionis regioselective;

o ,

ttn'

* r n"p,-", 16% aT1

The complex reacts with epoxidesto 1 (a) that undergoesinsertion with alkerr: Demetallationresultsin B-hydroxycarbo cyclopentenones.2

,q

\,/-r'intcol.

l-\'r-fttrcol,l a

2 ( m ' P1 1 4 - 1 1 6 " )

osi(cq)j

'':'l\Ax:'oo;", (o)

cH. l9H, I r _ _ /''JillJ"i - u N l^^ - 4 I

, l1 [ ,o I

'-l-

./\-'-'---+l t | _\VMn(CO)r CHr' LC",'

1o \-Y

---=;-

2) CHr=CHCOOCHT

trt)

Y

l]ln=...", , s e % f^f'os(cH! V,^

o..'.. ln'c*n'

x\'",, I

ll ,rl-R'

\#(*,

3

L. S. Liebeskind, J. R. Gasdaska, and J. S I P. De Shongand D. R. Sidler,ibid.. 41. {€92

Organomangonese reagents

kohols.t An attractiveroute to t ' .'t RVnBr followedbYreaction l.; r. senerallYhigher than that hc :-olated,intermediateketone' i:,'::'. the homoallYlicmanganese ,rc.:Irom RLi usingMnBr2, which

235

stitutedindenolsin 60-75voyield. Reactionswith 1-trimethylsilyl-1-alkynes results in 2-trimethylsilyl-3-alkylindenols. The regioselectivityof reactionswith unsymmetricalinternalalkynesis determinedby stericfactors;the largergroupis attached to the 2-position. Reactionswith ethoxycarbonylalkynes, however, lead to 2ethoxycarbonylsubstitutedindenolsregardlessof the other substituenton the alkyne. Pentacarbonyl(trimethylsilyl)manganese (l), 11,401. Improvedpreparation: (CHJ3SiOTf+ NaMn(CO), #

(CO)rMnSi(CH,), I

The complexreactswith epoxidesto yield a silyloxyalkylmanganese complex (a) that undergoesinsertion with alkenesor alkynesto furnish manganacycles. Demetallationresultsin B-hydroxycarbonylcompounds,spiroketallactones,and cyclopentenones.2 I. .\lthoughMnBr, is insolubleas )rc-cnceof LiBr, formedin situon 3659(1988) u.:' ': Letters,29,

l0r, f I); indenols.r ArYl ketones (2), whichafter )r:: .1manganacYcle into a Product ('\ converted is :tt 1-alkyl-1H-inden:ubstituted i, ::: Jlkvne reactsto form 2-subTr.::'..'.

(cH3)rsio liil" ?'.....yn,.o,.-""CH3^-^,ACoocH3

,-'d;Lo*,."] l-O

\.Y

l

f*'..*'

X\.",

(]j*?^. 'R'

3

.",=.".*n,, 82%

?" ?

gHrA=.A=^CooCH3

l) I

(o)ffi,"r)

I

cH,^,AMn(coil

2)cH'=cHcoocHr

,,A_

:

(cH3)3si? g

osi(cH3)3 iA a-- [ CH.F l.n,/-.-*ttol'

("-h /1

ff,__*i

ll 1.. ^^.. ,,z1r,OSi(CHr), 2)cH=cc.H, > lT seqo \,/....._r1_,a0",

HcooH "r*o , 3s%

i l - l

O.......Mn(CO)n

d";,

L. S. Liebeskind, J. R. Gasdaska, and J. S. McCallum,J. Org., 54,669(1989) P De Shongand D. R. Sidler,ibid.,53,4892(1988).

216

Organosilanes

Organoosmiumcompounds. (1). Preparation.' Dialkylnitriloosmium chromates, Ibur[N-Os&1(CrOJThesemetal chromatesare efiective catalystsfor oxygenationof primary and secondary alcohols.2Primary alcoholsare oxidizedexclusivelyto aldehydesand no estersare formed from secondaryalcohols.Primary alcoholsare oxidizedmore rapidly than secondaryones.

' M. E. JungandK. T. Hogan,Tetrahedroa It

Organotin reagents. a- A I koxya I ly I tributyI tins, Bu.SnCH undergoPd(d)-catalyzed couplingwirh A vinyl ethers(equationI).

1P.A. Shapley, T' 928(1988)' H. S. Kim, S. R. Wilson,Organometallics, ' N. Zhang,C. M. Mann,andP.A. Shapley, (1988)' Am' !oc,,110,6591

il

(I) C.HrBr + I (R= C'HJ + Organosilanes. Optically active binaphthylsilacycloheptanes. Jung and Hogan' have preparedthe opticallyactivebinaphthyliccyclicsilanes1 and 2, in which the chirality

In the presenceof BF. etherate.I ism with aryl aldehydesto form mainlv s-r.na

(lI) I i!g*+

(R)-l

Bu,SnclIrCH:CltoC (ZlE = t5: t5\

(s)-2

residesin the binaphthyl groups.These silanes(X = OCH.) can effect partial asymmetriccatalytichydrogenationof enonesand ketones.The highestenantioselectivity(35Voee)is observedwith (S)-3in an aldol reaction(equationI).

ever,thermalreactionsof I with arvl aldet vinyl ethers. l,l- D i meth oxy -3- trime thy I starr! l, tl). The reagentis preparedbr

(cH3bsioTf cH'cl'. -78'

+ C.HTCH(OCH')r-=#-

ryot"t""'*t-[( (s)-3

(179oee)

o

ocH"

i l H l

AYl-.^". t l \-/ (35Vo ee)

TMSOTf BF, Tic14

&% 27% ffi%

Organotinre&gents

237

'M. E. Jung and K. T. Hogan, Tetrahedron Leuers,29,6199(1988). t,lrCrO.)- (1). Preparation.' n e.nation of PrimarY and secciu.rrely to aldehYdesand no n .rcohols are oxidized more

Organotin reagents. a-Alkoxyallyltributyltins, Bu.SnCH(OR)CH:CH, (1).' These reagente undergo Pd(0)-catalyzed coupling with ArBr to give a mixture of (E)- and (Z)vinyl ethers (equation l).

cr 1 e:8 (1988). l l 0 " 5 9 1( 1 9 8 8 ) .

Pd(o),

(I) CuHrBr+ I (R = Crrf; -lurg and Hogant have Pre; I ;rd 2, in which the chirality

,\:

v

*5

C'HTCHTCH:CHOC2H5 (E/Z= 95:5)

In the presenceof BF. etherate,1 isomerizesto 1-alkoxyallyltins,which react with aryl aldehydesto form mainly syn-c-glycolmonoethers(equationII). How-

^.,.cHt tt-*

BFl.O(C'H<)"

(ll) I -:_--3

-fr" celrs9tl9' BuTSnCHTCH:CHOC2H' r (Z/E = 85:15)

OC.H. I C6H5\f"\zCH'

s5%

| OH (syn,93Va)

St - 2

- OCH,) can effect Partial The highestenantio' Lcrtrn€S. (equationI). reaction |d... \

ever,thermalreactionsof 1 with aryl aldehydesresultin mixturesof.syn- andantivinyl ethers.

(l).

l,l-D imethoxy -3-trimethylstannylpropane, (CH.).Sn(CH,),CH(OCH,), The reagent is prepared by reaction of (CHr).SnMgCl with

, cH3bsioTf -78'

Cll

cH,cl,, - --'--'--=--'-'--+

osi(cH3)3 * l ****,0, LY"

I

L-r.::"'""'""'J

?

4 . 4 :I

(l1Voee) i

ocH"

o

i l H l

^fc,q \-, (35Voee)

ocH3 TMSOTf BF, Ticl4

64Vo 27Vo 609o

90:10 66:34 60:40

23E

Organozinc reogents

to cis-fusedcyclopentanes It is usetul for [3 + 2lannelation Br(CH)rCH(OCH3)'' (equation l)'' and to spirocycliccompounds

-f

-I

t

cH:
t

cuH,

t

so2c6lt

o

can be conver Thesephenylsulfones and MgBrl'O(C,H.), of in the presence

| \o

'i:ti.tl:::k'

K' L' Euis'andN A' Richardson'

(1989) Visani,ibid.,45, 1167

--

Organotitaniu. t:"9_".1:t'

ad13,216). Diastereoselective

J"Tf l;'"'fi#l[:ifi'il',tl*', ]ii*.:-'

onin rizati eno "'*'" orreadv

+ROH

| sorcoH.

3-M ethyl-2-butenylzinc bronilc, I l'l-b is preparedfrom 1-bromo-3-methr sol solid. gray ethane). It is a sticky th in reacts unlike allylzinc bromide, o-all give the (2) unsaturatedacetal to zinchomoenolatecan be trappedsitb I (3).

;;;;;";"""'1:"::;:;IT""':,***;;":[ilJn'JJHThitl-'}1i:$*1il; wn tereofaceselectivitY'

t i' a,",Li\c,H,

*

'n'r1onl'...:Xi-tli-.,'" ^

c'H'/N"i-t,"''

I

zo-VcH, liH

r CH,:CH{ Ir + vrr2-vrr

-

: \J-c*L

;

,

8 2 :1 8 26:74

791o 667o

cHJic\ (CH3)3AI

uHr-

CoHt group is observedwhen the organometallics these selectivitywith both aromaticgroups' ir r"ptu."O by other 1541(1988)' Letters' andY Ukaji'Chem 'T. Fujisawa, A' Fujimura'

of 1

When heatedabove25' the inten tramolecularalkylation, particularlr ether (equationI). .'r'clopropanol

l) NiG)

and preparedfrom ArMgBr "'";;";;t,'n reagents'. , rL^ ^..onnzinc Organozinc reag,ents rhe organozi"" rhe

RA,':

I:is;';;iit""

"t cyclicethers'

( l )1 + 2 r y ( c ! ; c =

3'.hf*:'J"'tr"-ll'lJ[:#"i$liiii:H';ii;''G"oreagents'butno' reagents' from alkYl Grignard Lithium trialkylzincates(E' 5l5-5 ;;;;t"

a\

(o^ro,a.",

*

ccHsMsBr'ZnBrz, -

eM"

\oAcus'

"r' a Br/Zn exchangeat - 85oto form : :n intramolecularalkylation in the 1 nvolvesat leastpartial inversionat I

Orgonozinc reagents slrrJ:rto crs-fusedcyclopentanes

CH2=cHMsBrZnBr2 --'--

-

cuH,

,-l,*^I)b'", .,,-la(,

".ql:,^^qt11:l |

\o^sorcu",

+RoH

r. .:r,,i\t. Pereyre,Tetrahedron,45. . t r l . . 4 5 ,1 1 6 7( 1 9 8 9 ) '

L1.:16). DiastereoselectiveadI :(..tuse of readY enolization in re.ricnl reacts with marked diast'r.cr\'€d with (CH,),AI. Similar

:cHz

Thesephenylsulfones can be convertedinto acetalsby a reactionwith alcoh6ls the presence of MgBrr.O(CzH,),and NaHCO..,

|

rr

a

a.nrAO/'..cH

o^so2c6H5

NaHco3'rHF )t

7o-t6%

I

\oAo*

3-Methyl-2-butenylzinc bromide, (CHJzC:CHCHTZnBT (l).3 This reagenr is preparedfrom 1-bromo-3-methyl-2-butene andzinc (activatedwith 1,2-dibromoethane).It is a stickygray solid, solublein cH,cl,. This allyliczinc bromide, unlike allylzinc bromide, reactsin the presenceof NiBrr(pBu.), with the a,Bunsaturatedacetal(2) to give the o-alkylatedacetalexclusively.The intermediate zinchomoenolatecan be trappedwith Hro or RX to affordc,B-dialkylatedaceftilB (3).

cuH,. ?..;. ,oH

* cu,/S''l-a,", 2b

cIt

r8

:6

'14

3

s.'rrcd when the CoHsgrouP of I

r'

5 1 1( 1 9 8 8 ) .

e:.:- preparedfrom ArMgBr and c I'position of cyclic ethers' Thc r : : : r l G r i g n a r dr e a g e n t sb,u t n o t

when heatedabove25' the intermediatezinc homoenolateundergoesan intramolecularalkylation, particularlyin the presenceof ClSi(CH.)., to afford a cvclopropanol ether(equationI).

1) Ni([)

(I)1+2ry

(CHr)rC:

/"q, - CHCHCH2CH

CH"

t "

OCILCCHTOSi(CH3)3

I

cH3 Lithium trialkylzincates (E,515-516).1 1,1-Dibromoalkenes reactwith LiR.Zn \v aBr lzn exchangeat - 85'to form a 1-bromoalkenylzincate (a), whichundergoes rn intramolecularalkylation in the presenceof aceticacid at 0". The alkylation :nvolvesat leastpartial inversionat the carbenoidcarbon.

Osmiurntetroxide

U0

R-.a-a.rZnBu'Li

R-

tB' jL lC:C1 -B, + LiBu,Zn H/

-8.

H/

#:>.:.{, EIZ= 2.6:l

CuHs_r CH

R=

u,,,]*, "on"

CH,

-H

EIZ=l:1.8

,.",l.-}.<,

. LiBu,Zn ry

' J. S.M. Wai,I. Mark6,J. S. Svendsen. M. G Am. Soc.,rfl, 1123(1989).

Osmium tetroxide-Dihydroxypheny'borr Dihydroxylation of alkenes. CJ|a( formed on osmylationwith OsOoand )i-l unstableor water-solublediols. Osmylatia ln a nonaqueousmediumwith enhancedn

R-a-a"u H/

By useof this simpletechniquerhe ena astenfold.Thusthe ee for dihydroxylation from 8 to 78Voin a reactionof 78 houn.

tcr,i,c$cHnu o oo., cxr\^q ", clhq

rD. S. BrownandS. V. Ley,Tetrahedron 4869(1988)' Letters,29' 2D. S, Brown,S. V. Ley,andS. Vile,ibid.,29'4873(1988)' (1989)' I A. Janagisawa, Am' Soc' 111,366 andH. Yamamoto, S. Habaue, (1988). nT. Harada. Letters,29,3821 D. Hara,K. Hattori,andA. oku, Tetrahedron

Osmium tetroxide. Asymmetricdihydroxytation of alkenes(14,235-239). Further studyl of this reactionrevealsthat the optical yields of productscan be markedlyimprovedby slowaddition(5-26 hours)ofthe alkeneto the catalystin acetone-waterat 0'with can also be increasedby additionof tetraethylamstirring.The enantioselectivity hydrolysisof osmateesters.The report suggests facilitates which monium acetate, canundergoa secondosmylationto provide (1) osmylation of product that the first first osmylation. of the enantioselectivity 2, with reverse

Ita

O-Ot ' N. Iwasawa, T. Kato, andK.

Oxazaborolidines,chiral, 14, 239-242. (S)-2-Hydroxymehylindoline (l)t rcr the oxazaborolidine2, which functiom a

I

o o....ll....o o-ot\o

l,C

,,

I

I *'.

n'o

| ""o

+ R

,R

soAon

H

HO,

R .OH

il

Narasata,Ct*tt

|

ll

i

l

I

V*Aa",o"

Brt.c |

-

-'

BH3.S(CH,)3, but whichis requiredin sroilvields.Alkyl aryl ketonescan be reducedrn I but dialkyl ketones are reduced in only ,15-

I. K. Youn,S. W. Lee,andC. S. Pak,Tarobt

Oxrzaborolidines

.(::'"'#l>.:.{, EIZ = 2.6:1

a

I

:().\C

At

By useof this simpletechniquethe enantioselectivity can be increasedas much astenfold.Thusthe eefor dihydroxylationof 1-phenylcyclohexene canbe increased from 8 to 78% in a reactionof 78 hours. ' J. S.M. Wai,I. Mark6,J. S.Svendsen, M. G. Finn,E. N. Jacobsen, andK. B. Sharpless, Am. Soc.,f11, 1123(1989). Osmiumtetroxide-Dihydroxyphenylborane, OsO.-C.H,B(OH)r. Dihydrorylation of alkenes. c6H5B(oH), is useful for capture of the diols formed on osmylationwith osoo and N-methylmorpholineN-oxide, particularly unstableor water-solublediols. osmylationwith the boranecan alsobe conducted in a nonaqueousmediumwith enhancedrates.r

-Bu n

=r*J,c$*no

o oroo,cxrlr]o

qHjB(ol{h

CH2C12

I :9 :\69 (1988). estl). r,.-i :1" Lc . 111, 366 (1989). f i - , . . i r o n L e t t e r s , 2 9 ,3 8 2 1 ( 1 9 8 8 )

r lr i r:-239). Furtherstudy'of this R\r..-r.can be markedlyimprovedby at 0'with ilr: - ,i.rlrstin acetone-water tetraethylamof addition by .,.cd rn,: | : .mat€ esters.The report suggests to provide n.:r::\\ .rsecondosmylation . ' : : r l a t i o n . I

't'l{:-8'-:}l]

O-etlr..', ' N. Iwasawa, T. Kato,andK. Narasaka, Chem.Letters,l72l(l9gg). Oxazaborolidines,chiral, 14, 239-2A. (s)'2-Hydrarymethylindoline (l)t reactswith borane.dimethylsulfideto form the oxazaborolidine2, which functions as a catalyst for reduction of ketones by

BH3.:1sH3h)fr---i."

af--

-l' 'cH2oH

\A,

H

| / .,B-o 2

, | ",o J -

Ho/

\A*4.,

tl t

R

-2H2

R toH

BH3'S(CH3)3, but whichis requiredin stoichiometricamountto achievehighoptical yields.Alkyl aryl ketonescanbe reducedin this wayin 84-93Voee to (R)-alcohols, but dialkyl ketones are reduced in only 45-ffi% ee. I I. K. Youn,S. W. Lee,andC. S. Pak,Tetrahedron (1988). Letters,29,4453

U2

2-(Oxoalkyl)triphenylattoniumbromides

Oxazolidines.chiral. 3-Arytsulfunyloxazolidines.rTheopticallyactiveoxazolidinel,preparedfrom (R)-(N-toluenesulfonyl)phenylglycinoland2-hydroxymethylenecyclohexanone'

,<"'''

"+q

-?CuH' / \ NSOTqH? o Y Hs(cH2bsH)

oY,NSOTC?H?

cH#,-r "o

1

r^ i l

cH,1

lll!Ti14,".",,, frouo t , / \

i l - t

\./

X

\-/

\-,

Oxygen, singlet. Endoperoxidation. Conduritol-A (5) c cyclohexa-l.,4-diene via 2 by singletox!'ge provides the anti-endoperoxide3. Reducto followedby dpketalizationgivesthe oclotx

\.Ao'

q

|

2, CID- 1l3o

qHo Ho'.->-CHN "\,,/ I 4

additionof metal nucleophilesto the carbonyl undergoeshighly diastereoselective the chiral auxiliaryis group. on treatmentof the adductwith 1,3-propanedithiol, 4' releasedwith formation of the dithiane(3) of the aldehyde

Deoxygenation of cyclic peroxides.t o obtainedfor the first time by deoxygenatio peroxylactones (2) obtained by photosem (1). derivatives

rI.Hoppe,D.Hoppe,C.Wolff,E'Egert,andR'Herbst'Angew'Chem'Int'Ed''7A'6'l (1989).

SCHTCORBT-(1)' 13' 137; bromides,(C6Hs)rA 2-(Oxoalkyl)triphenylarsonium t4, t70. (E)-u,p-Enones.|Thearsoniumylidesformedfromthesesaltsreactwith conditionsto form (E)-a,p-enonesinTl-99% yield phase-transfer aldehydesunder particularly useful for reactionsof unstable lequaiion I). This Wittig olefination is aldehydesbecauseof the mild conditions'

'T + R'cHo :7]:"' '- ^1* (I) l[R = cH(cH,),, n-c,H111 (1988)' rY.-2. Huang,L.-L. Shi, and S.-W.Li, Synthesis,975

o

tl tn'-ioH ll R H

ll;%. H,cV R+ ;;* T

I,R=CHroreHs

,

Y. Siitbeyaz, H. Seqen, andM. Balci,I.C.S O ' Idem,J. Org.,53,2312 (1988). W. Adam,L. Hasemann, andF. Prechtl.Aarrr

Ozone a-Hydroperoxy carbonyl compouils.r ablytoo unstableto preparedirectly.but ca morestablet-butyldimethylsilylperoxidcs.

Ozone

from irc ,'razolidine1,,PrePared dr,' r r methYlenecyclohexanone, C A

?'"'

Oxygen, singlet. Endoperoxidation. Conduritol-A (5) can be preparedlstereospecifically from cyclohexa-1,4-diene via 2 by singletoxygenation(tetraphenylporphyrine), which providesthe anti-endoperoxide 3. Reductionof the endoperoxidewith thiourea2 followed by dpketalizationgivesthe cyclohexenetetraol 5.

r&ir'o"",,, _ O GK: GX",

,\so:c,H7 HS(CHr)rSH ---:----:-:--1

't{

43

3 I n,NcsNtr,, 8o7,JcH3oH,25-.

OH ; ^

a'Yu" i l r

cllo

ll

\lon : on

a\

to the carbonyl |e:.:.nucleoPhiles ra:rcJrthiol,the chiral auxiliaryis e . . J c h v d 4e '

o

t"'>Ao" ) \ . C - H , C O R B T -( 1 ) ' 1 3 , 1 3 7 ; rncJ from these salts react with yield n r [: r-cr.B-enonesin7l-99Vo rlr u.eful for reactionsof unstable

':

<

- i1-Cl2' 15-

u\\ ).

-

OH :

.

.X"'J" '^'orl

- rr.* - i ll l |m

X

rt",

\./-o''cH, : oH

Deoxygenationof cyclic peroxides.t o.-Methylene-B-lactones (3) have been obtainedfor the first time by deoxygenationwith (C6H,)rPof the o.-methylene-pperoxylactones (2) obtained by photosensitized oxygenationof methacrylicacid derivatives(1.).

Chem.Int. Ed''28,67 rr--' -lngew.

l:

I

.

tl RAg

f ;%. H,c\'

ffi-

t,R=CHrorQHs

o tl

",cvo

,..r.u, *+d o ffi *+o H

H 2

3

Y. Stitbeyaz, H. Segen,and M. Balci,l.C.S. Chem.Comm.,l330(1988). ' ldem,J. Org., 53,2312(1988). W. Adam, L. Hasemann,and F. Prechtl,Angew. Chem.Int. Ed.,27, 1536(1988).

o

*AA*

Ozone a-Hydroperory carbonyl compounds.t c-Hydroperoxy aldehydes are prob:bly too unstable to prepare directly, but can be obtained in l5-25Vo yield via the more stable Fbutyldimethylsilyl peroxides. Thus ozonation followed by reduction

1' obtained by sensitizedoxygenatron of the trialkylsilylated allylic hydroperoxides aldehydes2 albeit in low yield' of an appropriate alkene, providei cr-silylperoxy

*\

R\ n

r-Bu(CH1)tsicl

,',\-ooH'=;;;;rr I CH,

I (R = H' CH')

-\,oosi(cHr),-t-Bu rr

Palladium Exocyclic enol cthen exocyclicenol ethersin$ of an endocyclicdienol c catalyzedby Pd/C gives

I

CH, I l or. cnron ls -24% s(cH3h J

ot l ,,,/\-,oosi(cH,)'-t n l

-Bu

CH, , la,X=Cl

rb,X=C Desilylationof2resultsindecompositionattendedwithchemiluminescence.c(and in higher yield) by the same sequence Silylperoxy ketones can be p'"put"d by methanol' und ,h"r" .otpounds can be desilylated 121(1989)' andB' Will' Synrhesis' I W. Adam,L. H. Catalani, C' R' Saha-Moller'

No other hydrogenatio genationwas usefulfor :

RN, - RNHBoc.' r-butoxycarbonylaminr of di-r-butyldicarbonat

A. Takahashi, Y. Kirio. I ( 1989). ' S . S a i t oH, . N a k a j i m a M.

Palladium(ll) rcelrle. Lactonization ol dh aceticacidand benzoqu 2 and 3. The sterco:;e

. n:t.tined by sensitizedoxygenation rrr rldehydes2 albeit in low yield'

-

-OOSi(CH.)'-t-Bu CH. I

| '.. cs,on r * I s e x '. ia

Palladium Exocyclicenol etherc.t A routeto (E)-cyano-or -methoxycarbonyl substituted exocyclicenol ethersinvolveshydrogenationand isomerizationcatalyzedby Pd/C of an endocyclicdienol ether. Thus hydrogenationof la or lb in tolueneat -35. catalyzedby Pd/C gives (E)-2a or 2b as the major product in about 80Voyield.

o

H\/Pt

-Bu z'-.r,,, OOSi(CHr)r-t I CH, t

c[enJed with chemiluminescence' hrgheryield)bY the samesequence D c :h . 1 n o l .

ro>A* I \,/

ll

'ui'q'if;"", - la".-X.: + ' \ u(z\.2 ,_80% I x \-,

la,X=CN rb, X = COOCH3

G)_2a (E)-2b

ll:l t8:l

No other hydrogenation catalyst shows comparable stereoselectivity. This hydrogenation was useful for a synthesis of the antitumor agent nileprost (3).

(1989)' N q \\ill. Synthesis,121

(CH,),COOH

q

+;,\

3 RN, - RNHBoc.2 Vicinal azido alcoholsare converteddirectly into vrc-Nr-butoxycarbonylamino alcoholsby Pd/C-catalyzed hydrogenationin the presence of di-l-butyldicarbonatein ethyl acetateat 25". Yields are 71.-93Va. A. Takahashi, Y. Kirio,M. Sodeoka, H. Sasai, andM. Shibasaki, Am. Soc.,lll,643 ( 1989). S.saito'H. Nakajima, M. Inaba,andr. Moriwake,Tetrahedron Letters,l0,g37(1999). Palladium(ll)rcelate. Lactonization of dienesby 1,4-functionation.t Reaction of the diene 1 with aceticacidand benzoquinone catalyzedby Pd(oAc), resultsin the isomericlactones 2 and 3. The stercoselectivity of this lactonizationcan be controlledin part by A5

26

Pi||.di.i(nt

Prlledium(Il) acetrte.

CHTCOOH

i l t

v

HOAc,quinone, AcO.. (CH,LC=o,Pd(tr) ,

O

E

CouPling of CH':9115i(CH3le vi4 r fectedwith Pd(OAc), as catalyst.Added c hasthe additionalvirtue of suppressine dr trimethylsilyl-1,3-dienes.

+

I lV.

99:l

I

-40:60

50-577o

+ LiOAc, LiCl

tr

lactonesare additionof LiOAc or LiCl in catalyticamounts.Chlorine-substituted obtainedby additionof 2 equiv. of LiCl. 1,3,S-Trienes.2Thesetrienescan be preparedin moderateyield by Pd-catalyzedreactionof fumaryl chloride(1) with l.-alkenesin the presenceof N-ethylmorpholine (2), which is superior to Bu.N as the base. (E,E)-5-Phenyl-2'4pentadienylchloride(3) can also be usedin the condensation(last example),but this reactionis not (E,E,E)-specific. O

ll er)\*Cl

^ ll

o

PdG),2,

tm. ,coH,.A.AzcoH' + C.HTCH:CH,--F tP'e'el

r J.-E.Btickvall, P. G. Andersson, andJ. O V I A. Kasahara, T. Izumi,andN. Kudou.Srna ' R. C. LarockandD. E. Stinn,Tetrahedron L ' K. Karabelas andA. Hallberg, J. Org..ll. r9

Palladium(Il) acetate-1,3.Bis(diphenltl Carbonylation of allylamines.t This r vlationof allylaminesto give p,1-unsatura allylicamines. Co ---Ll3-

CHt*NBur+

f",

I + cH,oocc:cH, 'o*

r'

cH,ooc\

'

'fLoocH3

CHr_,2\..

(E,E,E)

Methoxycarbonylation. Arvl triflatcr zoatesby reactionwith CO and an alcoho binationwith dppp; yieldsare 72-951 . Tl phenolsundermild conditions.: This procedurewas usedfor the s1'nth

o

il

I

I, C6H5CH3

I

C.Hs,A'^Cl

+ CHr:CHSi(CH';.

+ + CrHrorCCH:CHz c6HSi\. ,/\''^-'cooc2H5 (E,E,E)-4,38%

+ (z'E'E)-4 l69o

cyclization ofo-iodophenyl allyl ethercto benzofurans.t This cyclizationcan (2 be efiectedin DMF with HCOONa (l equiv.), BurNCl (1 equiv'), and NarCO3 but known, is not formate sodium of equiv.) catalyzedby Pd(oAc)r. The function the salt improvesthe Yield.

;'#.r;ilTJ":, ay") 83% fY") $+c,H, \,4, \

CH,

I

I N(cJ!\

BzIOCHTO

I

ocH3

C@CH,

1q

I

BzIOCFIO

ocH!

Palladium(II) acetate-1,3-Bis(diphenylphosphino)propane

\=o )

Coupling of CHr:C115i(CHil with vinyl iodides.a The reaction can be effectedwith Pd(OAc), as catalyst.Added silvernitrate accelerates the reactionand hasthe additionalvirtue of suppressing desilylationand increasingthe yield of 1trimethylsilyl-1,3-dienes.

+ 99:t -10:60

lactonesare x ( hlorine-substituted

+cH,:er15i(.",), ry dti(cH3)3

ryt

purcJ in moderateYield bY Pd-catof N-ethyl.a.i.nes in the presence (E,E)-5-PhenYl-2,4i .,- the base. (lastexample),but h<';i,ndensation

IJ.-8. Biickvall, (1989). P.G. Andersson, andJ. O. Viigberg, Tetrahedron Letters,30,137 r A. Kasahara, (1988). T. Izumi,andN. Kudou,Synthesis,704 'R. C. LarockandD. E. Stinn,Tetrahedron (1988). Letters.29.4687 ' K. Karabelas andA. Hallberg, l. Org.,53,4909(1988).

:

Palladium(II)acetate-l,3-Bis(diphenylphosphino)propane, Pd(OAc),-dppp(1). Carhonylationof allylamines.t This is the mosteffectivecatalystfor carbonylationof allylaminesto give B,1-unsaturated amides,whicharereducibleto homoallylic amines.

I ' c^u\A''AzcuH' i

(E,E,E)

I, C6H5CH3

CHr,rZ',.,zNBur+ CO L ^lt

o ll cHr.,./"..-.cunr,

\,,=-\fcoocH3

I4J1*

CH,

i,E.E)-4,184a

-

\NBu,

Methoxycarbonylation, Aryl triflatesor iodidesare convertedinto alkyl benzoatesby reactionwith CO and an alcoholat 70' catalyzedby Pd(OAc), rn combinationwith dppp; yieldsare 72-95Vo.The method is usefulfor esterificationof phenolsundermild conditions.2 This procedurewas usedfor the synthesisof the aromaticsegment(1) of cali-

rE.E,E)

.,1_,,-1*/COOC2H5

cHr -rl'

+ (Z,E,E\-4 161o

o t*nzofurans.3 This cyclizationcan (2 r llLr.\Cl (1 equiv.),and Na2CO3 but known, is not ..rJium formate r.!

I

I

BzIOCHTO

co, car. N(qHr)r, DMSO/CHTOH , 44%

ocH3

ocH3 cH"

t " L',/>aCOOCH3 I

tl

aaoc4o\|ocu, ' l ocH3

Hcr,cH3oH I

8e%

Ho

coocH3 ocH3

Z8

Palladium(ll) chloride

a new classof natural antibioticand antitumoragents.Crystallization chemicins,3 resolutionto give the enantiomersof 1a. of 1 is accompaniedby spontaneous

with PdCl:or Pd(OAc),(10-20 molc 60"for t hour. The transformationm

CH" ?

r ' l l

'ly'Yt-o.n, t l HoA/-o

o

l

A

I

c

OR N'RBd

I CH"

I,R=CH.,COCH.. Bzl

CH, la I S. Murahashi,Y. Imada,and K. Nishimura,,/.C.S' Chem.Comm.,l578(1988)' ' R. E. Dolle, S. J. Schmidt,and L. I. Kruse,ibid.,904(1987). I K. C. Nicolaou,T. Ebata, N. A. Stylianides,R. D. Groneberg,and P. J. Carroll, Angew. Chem.Int. Ed.,n,1097 (1988).

Palladium(Il) acetate-Tiiphenylphosphine. Heck cyclization,t vinylation of halides in the presence of a hydride source (formic acid) can give cyclic products'

cH''133b'I:*, CFI'y ss% 4't$rr, *r^-r,,

o

$1*-r,, o

S. Adam, Tetrahedron Lerers. 29. 65trj r ' R. J. Ferrier, l.C.S. Perkin 1 . 1 1 5 5( t 9 ' r

Palladium(Il) chloride-Benzoqdn Oxidation of l-alkene4-ols- Tt lvtic)andp-benzoquinone (3 equir.t o hemiacetals), precursorsto 1but1'rol OH CHr:ggq"aHC6H.. I

coocH.

y'cHCH3 (Elz = 1 . 3l:)

Lettefs,x), I B. Burns,R. Grigg,V. Sridharan, andP.Stevenson,Tetrahedron T. Worakun, (1988). 432s,4329

Patladium(Il) chloride. Pyranosides- cyclohexanones.t The cyexomethylene pyranosides(1) de(2) by treatment canbe transformedinto cyclohexanones rivedfrom o-qlucosamine

J Nokami, H. Ogawa, S.Miyamoro. T I Leuers, 29,5181(1988).

Pdladium(Il) chloride-Copper(Il) d Oxidation-carbony lation of I -e,l 'rc palladium-catalyzed oxidation-ca r: 1) with CuClr as a reoxidantand .relds.l

Palladium(Il)chloride-Copper(Il)cNoride

t rntrtumor agents.Crystallization of 1a. i(\ {l\e the enantiomers

U9

with PdCl, or Pd(OAc), (10-20 mole Vo)in acidicaqueousdioxaneor acetoneat 60' for t hour. The transformationmay be relatedto the Ferrier rearrangement.2

o

ts',

o O(

(onztrl Bzlo f

NRBzI

oH NRBzI

I,R=CH:,COCH3, Bzl

( i^,;n1(61n7n.,1578(1988). I ( :,rS7). (,r.'ncberg.andP. J. Carroll,Angew'

D ::! presenceof a hYdride source

QuHt

IS. Adam, Tetrahedron (1988). Leuers,29,6589 ' R. J. Ferrier,J.C.S. Perkin1,1455 (1979).

Palladium(Il)chloride-Benzoquinone. Oxidation of I-alkene-4-ols. Thesesubstratesare oxidizedby PdCl, (catalytic) andp-benzoquinone (3 equiv.)or by CuCl/02 at 40' to .y-butyrolactols (cyclic I hemiacetals), precursorsto 1-butyrolactones. OH

CH,

*-rr,

CHr:6116n"HC6Hr3

coocH3

"o{o7r'"''

oxrd. ----------) 649o

'.-coocH, e5% Ctoi, rLso,,(CH,),c=o J

oYoTr'"" -coocH, i: Z = 1.3:1)

J. Nokami,H. Ogawa, S.Miyamoto, T. Mandai,S.Wakabayashi, andJ. Tsuji,Tetrahedron Letters, 29,5181(1988).

I P ;lc'renson, Tetrahedron Letters,29,

(f) de.e\r)methylene pyranosides (2) by treatment )r(..\ clohexanones

Palladium(Il)chloride-Copper(Il)chloride. Oxidation-carbonylation of l-alkenes. Thesealkenescan undergo an aerobic palladium-catalyzed oxidation-carbonylationin acetic acid-aceticanhydride (4:1) with CuCl, as a reoxidant and a trace of NaCl, required for satisfactory vields.l

250

Palladium(Il)chloride-Bis(salicylidene)ethylenediemine(salen)

CH'.. -2r4-pentanediol, (2F.r4F(

PdCl2, CuCl2, NaCl

RCH:CH, + co + Ac"o

Q'80'

,'

( Asymmetrization of meso-& R=qTL = CHzCeFIs = AcO

847o 86Vo 537o

CHrCl, at 0owith the homochira 4 with high diastereoselectir.itr (9: dialkylaluminum amide6 (9{:6).

PdCl2, CuCl2, NaCl

gry*4 HoCHrcH:cHr+ co + c2HioH

crH5ocHrqHcH2cooc2H5 I

oc2H5 I H. Urata,A. Fujita,andT. Fuchikami, 4435(1988). Letters,29, Tetrahedron

(salen)' Palladium(Il) chloride-Bis(salicylidene)ethylenediamine Hydrogenation catalyst.t PdcL and salen can form two difierent types of a palladium(Il) complex,a yellow complexI similarto complexesof Cu(II) and an insolublegreencomplex2, bestformedfrom KzPdCL,salen,and N(C2H5).asbase.

a-''"o + l - - - ' r

| cH3/'\-/

|

c

CH.

(tr

c;j"':b

(^)*(")*(" ' o o

l, yellow

a

o

N)

4a,R=H

! N \

\./ 2, grcen

Impuresamplesof 1 containinga greenimpuritywereoriginallybelievedto catalyze hydrogenation,but this activityis really due to the greencomplex,formulatedas 2. This complex is more effectivethan Pd/C for hydrogenationof alkenesand alkynes,and can reduce nitroarenesto anilinesdirectly. Reduction of internal alkynesafiordscri-alkeneswith slight contaminationwith an alkane. -I4 HO(CHJTC=CC2H5

(z) -Ho(cHr)rCH:CHCrH,

BuC:CH i13* BuCH:CHz+ CuH,o (981o)

(2Vo)

rJ. M. Kerr, C. J. Suckling,and P. Bamfield,Tetrahedron (1988). Leuers,29,5545

.-C.

Y. Naruse and H. Yamamoto. Tetalt

{. Pentenyloxymethylchloride. CH, r\ preparedby reactionof 4_penre Protection of alcohols.t pnnu POM ethers by reaction with I an :cseneratedby oxidativehydrollsrs Vicinaldiols are convertedinro "r'camphorsulfonic acid.The aceu

(s.len)

FrIriE

4-Pentenyloxymethyl chloride

(2R,4R)-2,4-Pentanediol,CH:"'a'^t-/cH:

RCIICH.COOAc

2Sl

(r).

oH 6H

o{;

Asymmetrizationof meso-ketones.rThe reactionof tri-i-butylaluminum in cHrcl, at 0'with the homochiralacetal3 of the ketone2 provides the vinyl ether 4 with high diastereoselectivity (9: l). Somewhathigherselectivityobtainswith the dialkylaluminum amide6 (94:O.

!n,

C:H5oCH2cHCH2cooc2H5 'l

!F n

o-\

oc2H5 ? ; . . L c t r c r s . 2 9 . 4 4( 13958 8 ) .

,-\+ l ---.----) j

I

)o^cu,

CH3

cHr/\'/ 3

dcnedismine(salen). a,cr .rn form two differenttypesof a of Cu(II) and an to complexes srn:r,.rr n l' ['JCl..salen,andN(CrHr).asbase.

-rmq"I i-nu.er, cH,cl,.o. J

cH'' o o R

,/\.. \r

, \ , /

\ ,ot

,rot

)po1 )po1 ) / \ / \ , / )o o N

CH, 4a,R=H

5a,R=H

!r.r'\-/ \

2, green ffir * g16originally believed to catalyze B :., lhe green complex, formulated as | ( :,'r hydrogenation of alkenes and u.:rc. directly. Reduction of internal I t r : i . r t t ( ) nw i t h a n a l k a n e .

f -ll() CH2)2CH:CHC2H5 , - t.'.ll , l l r

tt.),:.,i ron Letters,29, 5545(1988).

r"'YcHl

o o R

Q(CH,;, c -C T H , , C H N A I ( B) :u - r I

Bu-r 6 Y. NaruseandH. yamamoto,Tetrahedron, U,6021 fi9gg\. {-Pentenyloxymethyl chloride,CH,:6g1g1t2).OCH:Cl (pOMCl), l. The reagent rs preparedby reactionof 4-pentenolwith formaldehyde and hydrogenchloride. Protectionof alcohors.t primary and secondaryalcohols are convertedinto PoM ethers by reaction with r. and Hiinig's basein cHrclr. The alcoholsare regenerated by oxidativehydrolysisin aqueousacetonitrile(7g-gro/oyierd). vicinal diols are convertedinto acetalsby reaction with 4-pentenalcataryzed bv camphorsulfonic acid. The acetarsare convertedon reactionwith NIS into an

E2

Phase-transfercatalysts

alcohol iodo ether, which is reducedby zinc and a catalyticamount of NHocl in to the diol. rZ.Wu,D.R.Mootoo,andB.Fraser-Reid,TetrahedronLetters'29'6549(1988)' Periodinaneof Dess'Martin (L), 12, 378-379' aSShown,underoxidation.| The diol 2, preparedfrom 3-hexene-1,5-dyne methanesulfonyl with (3) treatment on 1,2-dibenzoylbenzene to goesaromatization OH

I ----o--r 1.ti;l: l1zCoc"u' ____?i

cHC6H5

Li CTHsCHO ----:--:-------4 14qo

4-6eo

ri \'Acoc.u,

CHC6H5

Li

3

OH ,

f,,*"*., I

o

?

tl

*-...1$ftllli,

t'n't\

CC#' + CC^H.

lt"o

2 + 1:l:l

I J -

monium bromide (equationI). Carbonrl quiresirradiation(350nm.). SrCrr

CJ

( t)Ar I+c o+

I-Chloroalkanes.2 The converstont with aqueoushydrochloricacidis not us€f The rateandyieldof this reactionarermp bromr& suchas cetyltrimethylammonium Esterinterchange,s Exchangeof mcr 1 equiv.of an alcoholand a base(K'CO I and in the absenceof an additionalsolrc catalrst. the absenceof a phase-transfer fff, + RCN.a Nitriles are obtatncdt of an alkyl halide,NaCN (2 equir.l- arx mole7o) in water (26 mole %) at lfil ot

I . A m e ra n dH . A l p e rJ, . O r g . , 5 35. l { - t 1 9 :B. Jur5ii,Synthesis,868 (1988). ' J. Barry,G. Bram,andA. Petit.Tetrahcd ' B. Jur5i6. l. Chem.Res.(S)'336( l9&rl

Phenethylamines. Alkatoid synthesistrom vic-tricatfu usedthe stronglyelectrophiliccharactero \vstemfor synthesisof severalalkalotds be preparedby reactionof a phenethlla

. ^"H-' H lZ

oc(clt

OH

4

of periodinane chlorideand a base,but in poor yield' Oxidationof 2 with 1 equiv' g ivesal:1:lmixtureoftheexpecteddiketone(4),thestartingmaterial(2)'and -an yield under isomerichydroxy ketone (5) which aromatizesto 3 in reasonable the sameconditionsas for 2. or CH'CI') can be o.-Keto esters.zThis periodinane(suspendedin CH'CN 25o' at esters a-keto to usedfor oxidationof c-hydroxy esters

I( cll I

(1988)' Letters,2g'4681 I S.J. Danishefsky, andN. B. Mantlo,Tetrahedron D. S.Yamashita, (1988)' I J. P.Burkhart, ibid',29,3433 N. P.Peet,andP.Bey, Phase-transfercatalYsts. Carbonylation of ArI to form ATCOOH can be effected ArI --+AttOOH.r catalyst,cetyltrimethylamby catalysiswith nickel cyanideand a phase-transfer

ocH3

Phenethylamines

ir:.1r\tic amount of NH4CI in alcohol

monium bromide (equationI). Carbonylationof ArI catalyzedby Cor(CO), requiresirradiation(350nm.).

4;,.,.:r('n Letters,29, 6549(1988).

) asshown,underr .l-hrrene-1,5-dyne withmethanesulfonyl 3 , ,,1Ireatment

':.'

--' ,,T: ^- 4lCoceHs \A.o..", r

3

r)

1"."',", 'l*'"'n''

(l) ArI + CO

Ni(cN)r, cr6H11N(CH3)3Br' C,H,CH,, H,O, NAOH

AICOOH

40-80qa

I-Chloroalkanes.z The conversionof primary alcoholsto l-chloroalkanes with aqueoushydrochloricacidis not usefulbecauseof mediocreyields(30-607o). The rate and yield of this reactionare improvedconsiderablyby useof a surfactant bromide or cetylpyridiniumbromide. suchas cetyltrimethylammonium Ester interchange.sExchangeof methylor ethyl esterscanbe conductedwith I equiv.of an alcoholand a base(KrCO.) in the presenceof Aliquat or BuTNHSO' and in the absenceof an additionalsolvent.Indeedit can be carriedout at 70'in catalyst. the absenceof a phase-transfer RX + RCN.a Nitriles are obtainedin 75-93Voyield by heatinga suspension bromide(1.5 of an alkyl halide,NaCN (2 equiv.),and cetyltrimethylammonium mole Vo)in water (26 mole Vo)at 100' overnight. I. AmerandH. Alper,J. Org.,53,5147(1988). :B. Jur5ii,Synthesis,868 (1988). 'J. Barry,G. Bram,andA. Petit,Tetrahedron (lgti|). Letters,29,1-567 ' B. Jur5ii,J. Chem.Res.(S),336(1988). Phenethylamines. Alkaloid synthesis from vic-tricarbonyl compounds. Wasserman'sgroup' has usedthe stronglyelectrophiliccharacterof the centralcarbonylof a ulc-tricarbonyl systemfor synthesisof severalalkaloids.Thus severalisoquinolinealkaloidscan be preparedby reactionof a phenethylaminewith the tricarbonyll.

o

o

l l l l

r)ll

: ':'. b:r ,rf 2 with 1 equiv.of periodinane to:: r{). the startingmaterial(2), and yield under to 3 in reasonable t'1.:::./.\ can be F.-:Jdd in CH,CN or CH'C!) r i c : , ' c s t e r sa t 2 5 o . 4681(1988). Letters,29' Tetrahedron li: t :::r (1988).

lH_ -"o frH'

^aYoc(cH3)3^t"'offi * cH"oV

6

.""oV

ocH3 cH3o

cHro

'"'o)aA #"cH3oY

f)^"

cH3oY .{:l :o form ATCOOH can be efiected f\' -: r.tnsfercatalyst,cetyltrimethylam-

253

ocH3 PaPavera.ldine

Phenyl dichtoroPho4b Phenylboricacid I J. G. de Vries, and S' A' Hubbard' l'C'S' Chcn'

Thereactionottryptamine(4)withthetricarbonylcompound3providesaroute to indole alkaloids.

'"Zd)ooc2Hi.Gf*,a

3

S-Phenylcarbonochloridothioate,C.flSCO 1 L4-Keto aldehydesor 7,4'diones' Rea Cl'St Grignard reagent2a ot 2b catalyzedby Gn second of a to 3 in 80-85% yield. Coupling

H 4

: c6H5s y cr . lX[",),rugn, tl o 2a:l =:" . |

N H

r-BuOOC'i Ebumamonine

Letters'30' andJ' H' vanDuzer'Tetrahedron tH. H. Wasserman, R. Amici,R Frechette' 86e(1e8e). Phenylboricacid, C.H'B (OH)z' of.stilbene to photocyclizationfrom benzoin' The Phenanthrenequinon) This stepcan be circumvented phenanthrenerequiresu "in' to cis isomerization' b y r e a c t i o n o f b e n z o i n w i t h p h e n y l b o r i c a c i d t o f o r m t h e l , 3 - d i o xin oborole2.This by photocyclization the pres' adductcan be convertedto pt"nuntt."n"quinone enceof diphenyldiselenideas the oxidant'

A \./

2\

(.,\A"

c6H5B(oHh, "c'gi'a-, 4\

e'% \|fl"

1) rtv, (C.HrSeL 2)OH,OI

A \r/

84%

O-B'

OH

'cuH'

'

)

resulu (12,551) followedby deacetalization : CH.)' l,4-dione(R andF Nas'o'lct I V. Fiandanese, G' Marchese'

iodidcPhenyl dichlorophosphate-Sodium combin The iethioacetalization't acetalsto t C6H,OPOCIr,and NaI converts thioaceta on Uut tu, little, if any, effect into thioketals addition of DMF converts 70-' in hours at room temperaturein 1-17

,

A

(YY ff"

o 3

ff

X

C6H5OPOCI2'llCOi(O

![,\.4.",

I H.-J. Liu and V. Wiszniewski'TetrahedronL

Phenyl dichlorophosphate-Sodiumiodide'-Dimethylformamide

nr I compound3 Providesa route

'

l

I -

r J . G . d e V r i e s ,a n d S . A . H u b b a r d , J . C . S ' C h e m ' C o m m ' , 1 1 7 2 ( 1 9 8 8 ) '

?

(1). C6H5SCCI S-Phenylcarbonochloridothioate, of this acid chloride with the Reaction or l,4-diones. I,4-Keto aldehydes (I2,171) resultsin coupling by cl,Ni(dppe) 2b catalyzed Grignard reagent2a or catalyzedby Fe(acac)r reagent Grignard of a second yield. Coupling to 3 in 80-85%

> osvo

NH,

255

i/

I

Nirn\ ''""'t

cuHrs- cl + _ tl

o..,zo CoHsS-n,z1,)(-R

o

o

2a,R=H 2b, R = CH:

I Ebumamonrne

3 I rr n'urx,rdm) ro-eo%zyx,oi |

*'#*

! .:1 [)uzer. TetrahedronLetters,t0'

o

o th,'tt.rcvclizationof stilbene to n l'hrs stePcan be circumvented 2. This frrrmth€ 1,3-dioxoborole in the Presr 5i photocyclization

4 resultsin a 1,4-ketoaldehyde(R : H) or a (L2,557\ followed by deacetalization 1,4-dione(R = CH,). (1988)' lV. Fiandanese, Leuers,29,3587 andF. Naso,Tetrahedron G. Marchese,

/-\ I

1) ,rv, (C6HrSeI 2)OH.O,

'

'

84%

z\ ._

o \CoH,

)

Phenyl dichlorophosphate-Sodiumiodide-Dimethylformamide' D e t h i o a c e t a l i z a t i o n . t T h e c o m b i n a t i o no f p h e n y l d i c h l o r o p h o s p h a t e , CoH,OPOClr,and NaI convertsacetalsto the correspondingaldehydeor ketone, but has little, if any, effect on thioacetals.However, the reagentobtained by addition of DMF convertsthioketalsinto the correspondingcarbonylcompound at room temperaturein 1-17 hours in 70-95Voyield.

o tl

f\

CH,

Xl

HCON(CH|2,NaI (1:1:4 5) C6H5OPOCI2,

-

t

CH, \-,\

CH, \CHt

I H . - J . L i u a n d V Wiszniewski,Tetrahedron Letters, 29, 5471( 1988)'

cH3

Phenylethylisocyanate

256

Phenyl dichlorophosphite,C.H,OPC!. Phospholipids. This phosphitein combinationwith ethyldiisopropylamine can be usedto preparephosphitetriesters,whichon oxidation(HrOr) and deprotection

Bzl resultsin oppositediastereoselec are readily convertedto derivativesof r l) (i-Pr\Nqlq

l) HzQ

c6H5OPCl2

0) RoH+ RroH

o*

o il

, RoPoR''tP

* oPoR .

oc6H5

OH

I + BCHrCooCuH, 3lg.-0-tot 2

C

t

I

furnish phosphateesters.This protocolprovidesa route to typical phospholipids:

o

3_+

o

- I

-NHCbo l-----

RCOI

*'$o-l LOH

r)c6H'oPcLll

2)H,o,

overau

t

l

| !l "\nAcn CuHt' I

E5%

RCOr +HocH,iHcoon'rffi*'go--]]| 'l'' L-OPOCH2CHCOOH

d

aoYo

l) NaNIS(CH,)!1, 2) CH,I.-78'

Boc

4 (3RnS> l0

d

lt

OH I S. F. Martin and J. A. Josey,Tetrahedron Letters,29,3631(1988).

Phenylethylisocyanate,ocN6u1cH,)C6H5 (1)' Availablefrom Aldrich or Fluka' with ( + )- or ( - )-1 results Resolutionof sec-amines.r Reactionof sec-amines which can usuallybe resolved in two diasteriomericureas,RTNCONH(CH,)C6H', is obtainedby or crystallization.The resolvedsec-amine by either chromatography alcoholysisof the opticallypure urea. The methodis particularlyvaluablewhere both opticalisomersof the amine are desired;seealso (R)-( )-(1-naphthyl)ethyl isocyanate(6, 416)for a similar reagent. I B. Schonenberger org. andA. Brossi, (1986);L. A. Chrisey He\v.,69,1a86 andA. Brossi, 1989. Syn.,submitted

aoH o-2-phenylglycinol, coH,

t -NH,

(1). both o- and L-l are availablefrom Aldrich.

a-Amino acids.l Condensationof o-1 with phenyl 2-bromoacetate(2) in followed by reaction with Boc,O provides3 in 40-70Vo ethyldiisopropylamine overall yield. This product servesas a substitutefor a chiral glycinein enantioselectivesynthesisof cr-aminoacids.Thus the enolateof 3, generatedwith sodium reactswith alkyl halidesat - 78"with highdiastereoselectivity hexamethyldisilazide, to give (3R)-derivatives(4). Note that changeof the Boc protectinggroup of 3 to

(,Yo C.Hr"'\T

4

l) NrN{S(CH,\}: 2) BdBr

t3t

q

Bzl

Icra J. F. DellariaandB. D. Santarsiero.

Phenytiodine(Ill) bis(trifluororccflc ) Ox id ati o n o/ P'alkoxYPlerol or C.H.I(OAc),:to/ C.H5I(OCOCF,)z' CAN can also br intermediates. acetal Hofmann reaftangemenr-t Tuo I valent iodine reagentis useful for re amines,without effect on a seconda fai here,the Hofmann rearrangement

ATSOTNH(CHr)jCONl!

Phenyliodine(Ill) bis(trifluoroacetaie)

can N! 'n * ith ethyldiisopropylamine 'rJation (HrOr) and deprotection n : HzAz

tR

: H'. PIOJ --::----2+ 90%

on alkylation.The alkylatedproducts Bzl resultsin oppositediastereoselectivity acids. ct-amino of derivatives converted to readily are l)(i-PTLNC?Hr

o tl

257

2)Bo:9+ I + BCHTCOOC6H5:40_70*

2

ROPOR'

I

,ZO"ZO

I .L

) cu"," -T

I

Boc

OH 3 lr. .: rout€ to typicalphospholipids: l) NNls(cH!),1, 2) CHJ, -78' 3

o F.

r-

85%

CuHr"'\N

tl

RCO-

1

^n:.rr--l : l A

('Y"

)

o

ll

HCl, C2H5OH

r

-oH

t

CH" .

c.H,"'\;'ncooc2H5

g4

HrCl-

NH,

Boc

I

L-OPOCHTCHCOOH I OH

4 (3R/3S> 200:1) | ",, tt.

l.-

9H,

!e :nll (1988).

crH,i ,r \r.iilablefrom Aldrich or Fluka. with ( + )- or ( - )-1 results ?t-:nilr'l€s C.ll . uhich canusuallybe resolved is obtainedby [c :r.trlvedsec-amine :ti .1r\ particularlyvaluablewhere ; ) , , . r / r o( R ) - ( - ) - ( 1 - n a p h t h y l ) e t h y l

-zO..rz-o I |

f |

,-o',?o l) NaN[s(cH!),], 2)BzlBr

| |

----;-

| |

cou,"'\N/

cult,"'\*/

coocrHs

Bzl

"cH2c6H5

Bzl

(1988). Letters,29.6079 Tetrahedron J. F. DellariaandB. D. Santarsiero, andA. Brossi,Org. ls\^ . L. A. Chrisey

arJ : -l are availablefrom Aldrich. (2) in rr:h phenyl2-bromoacetate rr:h Boc:O provides3 in 40-70Vo rtc !.)r a chiral glycinein enantiosewith sodium n.'.:re of 3, generated -\' with highdiastereoselectivity Ir (ri :nL-Boc protectinggroup of 3 to

CoH.I(O,CCF.)r(1). Phenyliodine(III)bis(trifluoroacetate) O x i d a t i o n o / p - a l k o x y p h e n o l s . T h e s e s u b s t r a t e sa r e o x i d i z e d b y or CoH,I(OAc),'to p-quinonesin high yield, probablyvia hemiC6H5I(OCOCF.)2' acetalintermediates.CAN can also be usedas oxidant but yieldsare lower. 5 havereportedthat this hyperHofmann rearrangement,t Two laboratoriest valent iodine reagentis useful for rearrangementof primary amidesto primary amines,without effect on a secondarysulfonamidegroup. In the examplecited failed completelyunder usualconditions. here,the Hofmann rearrangement

ArSO,NH(CH2)5CONH2 #

ArSorNH(CHr),NH,

258

Phenyliodine(Ill) dircetete

Dethioacetalization.6 This reactioncanbe effectedwith C.HrI(OCOCF3),(L) in aqueousmethanol(9:1) or acetonitrileat 25'without effect on ester, nitrile, hydroxylgroups,or unsaturatedbonds. l, --cH,oH. H,o "= )

bis(phenylsulfonyl )rcl| Phenyliodonium 129-13r.". Preparation:

S___r p-(CH,)rNCuHo{

,/

\

s-/

p-(CH,)TNC.H.CHO

gem-B i s( ph eny Isulfu nyI )cycI optry kenesthermallyor photochemicalll'toI The productsdecomposeslowly on stan are formed from alkYnes.

I;,x;);;il'>':o o ll

o

-scrH, :|;-} , "r".u

C6H5SC(CH2)4CH: -sc.H.

e7%

+ C[!(SC CuHrI(OAc),

ll

C6H5SC(CHJ4CH(OCH3),

IY. Tamura,T. Yakura,H. Tohma,K. Kikuchi,and Y. Kita, Synthesis,126 (1989)' 2 A. Pelterand S. Elgendy,Tetrahedron Letters'29,677(1988). 3 E. S. Wallisand J. F. Lane,Org' React''3,267(1949). , G. M. Loudon,A. S. Radhakrishna, M. R. Almond,J. K. Blodgett,and R. H. Boutin,./. (1984). 4272 49, Org. , -H. 5 V. M. McParland,M. whitehead,and I. G. C, Pavlidis,E. D. Chan,L. Pennington, C o u t t sS . y n .C o m m . . l E ,l 6 1 5( 1 9 8 8 ) . 6 G. Stork and K. Zhao, TetrahedronLeuers,30,287(1989).

I L. Hatjiarapoglou, N. \l "\l A. Varvoglis. ( 1e88).

Phenylisocyanate,C6H5N:C:Q. cis-Oxazolidin'2'ones.t Anl isocl sulfonylisocyanate,reactwith vin;-lepo form the lessstablecis-oxazolidinone vinylepoxide.

/

Phenyliodine(IlI)diacetate. Iododecarborylation. Primary and secondaryacids undergo this reaction when treatedwith C6H5I(OAc),and iodine (equationI).' L' CCL

(I) RCOOH+ C.H,I(OAc),

n'

, [RCOrl] T#

RI + CO,

The reaction can be extendedto aromatic acids that are soluble in carbon tetrachloride.2

--OcooH

r,#-+t +cuH,I(oAc),+

rJ. I. concepci6n, andE. Suiirez, J. A. Salazar, R. Freire,R. Hern6ndez, c. G. Francisco, l . O r g . , 5 1 , 4 0 2( 1 9 8 6 ) . ' R. Singhand G. Just,Syn. Comm.,lE' 1327(1988)'

P.\ . r .cH:cH,

C6H5(CH)2'

+ C.ILN:

= 1:2 cisltrans

isocyanatc If 2-methoxy-1-naphthyl cleaved by CAN to furnish the corres 70-85VoYield. ' B. M. TrostandA. R. Sudhakar. Am' h<

Phenylisocyanidedichloride' CuH'\Dialkynyl ketones.t In the Presc kynyltin compounds(2) to give (N-pfr Theseproductsare hydrolyzedto diall etherate)in -60Vo yield. Under the sa couplingto alkanes.

Phenyl isocyanidedichloride

e (iccted with C6H'I(OCOCF,), (1) lj $ithout effect on ester, nitrile,

C6H5I*C-(SO,C.H'),(1), -.p. Phenyliodoniumbis(phenylsulfonyl)methylide, 129-131..". Preparation:

CHr)2NC6H4CHO

t

+ Crt(SOrC6H5), CoHrI(OAc), #

gem-Bis(phenylsulfunyl)cyclopropanes,tThe reagent reactswith simple alin 25-70Voyield. kenesthermallyor photochemically to give thesecyclopropanes The productsdecomposeslowly on standingwith lossof SOr. Complexproducts are formed from alkynes.

o c. I t.sc(cHr)4cH(ocH3)'

(1989). re \ Kita. Synthesis,126 . ^-- r19t38). n.: I K Blodgett,and R. H. Boutin,J. ( . i ' , r l u n d .M . W h i t e h e a da,n d I . G . C .

IL. Hatjiarapoglou, Perkin1,2839 A. Varvoglis, N. W. Alcock,andG. A. Pike,./.C.S. ( 1988). Phenylisocyanate,C6H,N:C:O. cis-Oxazolidin-2-ones.tAryl isocyanates,with the exceptionof p-toluenesulfonylisocyanate,reactwith vinylepoxidesin the presenceof a Pd(0) catalystto of the form the lessstablecrs-oxazolidinones, regardlessof the stereochemistry vinylepoxide.

.'rs9).

i-

259

o

fl .cu:cu,

/--];

rni.,rr acids undergo this reaction q u . r l t t l nI ) . r

C6H5(CH2)2/ cisltrarc = l:2

+ C.H'N:C:O

/(

(Ro),P Pd(o), t"t t

O H..\

88%

C6H5(CH2);

N_C^H. " t..H 'CH:CHz

cis,3: I R ( ( )- . 1 |---=-,

7O-94Vo

RI+COt

rc .rcids that are soluble in carbon

can be If 2-methoxy-1-naphthyl isocyanateis used, the N-aryloxazolidinone cleavedby CAN to furnish the correspondingN-unsubstitutedoxazolidinonein 70-85Voyield. (1988). B. M. TrostandA. R. Sudhakar. Am. ]oc..110.7933

r . ' u^ ' ,R 4 '

i-55qo

Vt

\:/

l ( : : ' . 1 n d e z ,J . A . S a l a z a r ,a n d E . S u 6 r e z . I

Phenylisocyanidedichloride,C.H.N:CCI, (1), 6, 458. Supplier:Aldrich. Dialkynyl ketones,t In the presenceof Cl,Pd[P(CoH,)3], I coupleswith al(3) (2) give (N-phenyl)dialkynylimines kvnyltin compounds to in 30-75% yield. products (4) These are hydrolyzedto dialkynyl ketones by aqueousacetone(BF. -60Vo yield. Under the sameconditions,Grignardreagentsundergo etherate)in iouplingto alkanes.

260

(-)-E Phenylmenthol

o . l l

Pd(tr)

I + 2 BurSnC=CR#

C6H5N:C(C=CR),#

t

O:C(C=CR)'

3

Ar-ROC1_

tl

4

*\*-

.,,ilgl

o

ri' I + 2 RMgBrJHf' r'P-P + C6H5NC (1988). Letters,29,5379 IY. Ito, M' Inouye'andM. Murakami,Tetrahedron R*OH' ( - )-8-PhenYlmenthol' Reaction of the AsymmetricWittig-Honrcr reaction; chiral olefinations't'z (2) at phosphonoacetate chiral ketoneL with the ylide from (-)-g-phenylmenthyl is alkene the - 30 to - 60' givesttre ie;-otenn in a 90: 10 ratio' The geometryof

CH

determinedmainlybythechiralauxiliary'Useofet?'-2resultsin3withtheElZ

I

CH

ss.lcHr)r

-30 b -60'

ll I + (cH3o)2PcH2cooR* -e5ry, , cH2osiR3

I H.-J.Gais,G' Schmiedt. \[' A I (1988). 1773 29, Letters, r H. Rehwinkel'J. SkuPsch. and 'M. Ihara,Y. Takino,and K Fu 63 (1989).

+ (Z)-3 -90:10 cH2osiR3

rkl PhenylselenoPhosPhonic r of phenvldichloroPhosPhin '

)c:o-)c:st.'

(E)-3

ratioofabout20:80lng}Toyield.Thischiralolefinationislimitedtoenantio. mericallYPure ketones' the 8' Michael reaction't Treatment of Asymmetricintramolecular double triflate ester (2) with t-butyldimethylsilyl phenylmenthyf",p-un'ut'ul"O amide andtriethylamineeffectsthisMichaelreactionwithalmostcompletediastereoselectivitytogivetheindolizidine3,whichwasusedforsynthesisof(_)tylophorine (4).

t

comPoundsto form carbo-nYl

(cH.\ \

' H. W. RoeskYand W' Klokcr' rJ. P. Michael'D. H' Reid' B ( 1988).

dichloride Phenylselenophosphonic

261

o

H^O+ ;CRr. -5

O-C(C=CR),

.tl

Af\Rocl

4

'__\

ll *\r*J

tl

lBuMe,si'rr Ar N(c,H5)!'20') 74-8sqo Ar

o

o 3 (4:l)

L t ::i r r . 2 9 . 5 3 7 9 ( 1 9 8 8 ) .

z,er={

focH, ocH3

I olefinations.\'2Reactionof the 'lmcnthylphosphonoacetate (2) at rt' The geometryof the alkeneis oi tnt-2 resultsin 3 with the E/Z

(

. ii:

i

ocH3

+

' H.-J.Gais,G. Schmiedl, andI. Erdelmeier,Tetrahedron W.A. Ball,J. Bund,G. Hellmann, Letters, 29,1773(1988). r H. Rehwinkel, J. Skupsch, andH. Vorbrtiggen, ibid.,29,1775(1988). r M. Ihara,Y. Takino,andK. Fukumoto, Heterocycles,28, special issue, andT. Kametani, 63(1e8e).

+ (Z)-3 -90:10 cH2osiR3 OH (E)-3 ,,.rrinationis limited to enantioI reaction.t Treatmentof the 8) srrh r-butyldimethylsilyltriflate rrlh almostcompletediastereoseof (-)tylophorine :d for synthesis

Se

tl

The reagentis preparedby reaction Phenylselenophosphonic dichloride,C6H5PCI2. with seleniumat 170-175'.r of phenyldichlorophosphine \ \ with enonesand severalmasked )C:O-+ )C:5e.2 The reagentreacts compounds. carbonylcompoundsto form selenocarbonyl

'€iil+i'C;". ' H. W. Roeskyand W. Kloker, Z. Naturforsch,?3R,697 (1973). rJ. P. Michael,D. H. Reid, B. G. Rose,and R. A. Speirs,,/.C.S. Chem.Comm.,1494 ( 1988).

2C2

l.Phenylsulfonylpropanol-2

4-(Phenylsulfonyl)butanoic (L). acid, C6H,SO,(CHr)3COOH 2-Piperidones. The dianion (2) of L reacts with imines activated by BF3 etherateto afford, after cyclization(TFAA), substituted2-piperidones(3). These lactamscan be convertedto substitutedpiperidines(5) by desulfonationand LAH reduction.t

trlr

r)2BuLi H 9H 2)RcHo C6H'SO2 .,\, + 7o;* |

noA

R

1,3-na

t4r"N

I K. Tanaka,K. Ootake,K. Imai. N. Tan,l. r R. Tanikaga,K. Hosoya,and A. Ka1. .l ('

l) BF3.qqH5b

ll

+2')**

HC- -CH:CHCeHs

87%

,

3

,rnfnu",

Phenylthiomethylenetriphenylphocplcr tion.l Lactone ring erpansion.2 The -y-la

1-lactol 4, characteristic of merinic aod Wittig reagent to provide a vinvl sulfidc ,

NmMq'. o4oAaH2osiR3 CuHi

CuHt

l) DIBAX

t't

2, Rr= t-3u16.[lt;t

'C. M. Thompson, (1988). l. Org.,53,5389 D. L. C. Green,andR. Kubas, (1). C6H.SO2CH,CH(OH)CH3 L-Phenylsulfonylpropanol.2, Reactionwith electrophiles. The dianion of this and other B-hydroxysulfones Thus the dianion of (S)-1 is alkylatedat the showsunexpectedstereoselectivity. whichcanbe mark' positiono to the sulfonylgroupwith high syn-stereoselectivity, edly affectedby additives.l carried out by alkoxymercurationfolb closure. l) 2BuLi OH zl ctL=cHcH'Bt' I C6H5SO2V.A.CH,L

(s)-r + HMPT + TMEDA

83%

79% 82%

OH I cuHrsot;A69" + anti-2 I CH'CH:CHr73:27

sYn'2 ;r;i?

is similarto that with alkyl halides The reactionof the dianionwith aldehydes isomer'2 andresultsin formationmainlyof the 1',3-syn

(19&< Letters,4995 T. J. Lee,Tetrahedron :A. H. Davidson, C. D. Floyd,C. N. Lerr (1988).

Phenylthiomethyl(trimethyl)silane,CJI g-Hydroxyalkyl phenyl sulfidcs.t I silanecan effect phenylthiomethylatio ethersof B-hydroxyalkylphenylsulfidc in THF shouldbe dried with 5-A molo

Phenylthiomethyl(trimethyl)sihne

) ( ooH (1). rt\ $ith iminesactivatedby BF3 (3). These lb!:rtuted2-piperidones rnc':(5) bv desulfonationand LAH

r)2BuLi H 9H 2)RcHocuHrsor:t'gH,

()Ir;so%-

|

HoA *

+

H 9H c6Hjso2-4a", |

-80:20

"o"'\*

1,3-syn

|,3-anti

(1983). K. Tanaka, K. Ootake, K. Imai,N. Tanaka, andA. Kaji,Chem.Letters.633 'R. Tanikaga, K. Hosoya, andA. Kaji,J.C.S.Perkin1,2397(1988). (CeH,).P:CHSC6H. (l). PreparaPhenylthiomethylenetriphenylphosphorane, tion.' Lactonering expansion.z The 1-lactone2 can be expandedto the protected of mevinicacids,by reactionof the lactol of 2 with this 1-lactol4, characteristic Wittig reagentto providea vinyl sulfide3. Conversionof the vinyl sulfideto 4 was

3

I

e3% Nr/H8 J

,,,.

t"'-N\

o

MEMO

MEMO

n

-.."s!

o4oA"H2osiR3 2, R3= t-Bu(C6H5)2

4

I) DIBAH

2)r

-_.-.---> u%

c.H.sCH:CH lrcH,osiR3 I OH

3 I l) Hg(OAclz,HgO,CH3OH 70% 2) NrBHl I Y

. r , ' i . 5 3 ,5 3 8 9( 1 9 8 8 ) .

gNGM rli cH. (1). f ::rr.andotherB-hydroxy sulfones ianr,.nof (S)-1is alkylated at the whichcanbemarkre,..electivity,

),-r t

^ t l cH,o^g^cH2osiRl 4

carried out by alkoxymercurationfollowed by reduction and concomitantring closure.

OH I

cn, '

+

anti-2

CH.CH:CHz 73: 2 7

' T. J. Lee,Tetrahedron (1985). Letters,4995 ' A . H . D a v i d s o n , C . D . F l o y d , C . N . L e w i s , a n d P . L . M yCe hr se,m " /..C Co. S m.m . , l 4 l 7 ( 1988).

syn-2

58:42 8 5 :1 5 i ::rrrlarto that with alkyl halides c n er . :

Phenylthiomethyl(trimethyl)silane, C.H,SCH,Si(CH,),(1), 10, 313-314. p-Hydroxyalkylphenyl sulfides.t In the presenceof BuoNF(0.1 equiv.) this silanecan effect phenylthiomethylation of aldehydesor ketonesto provide silyl ethersof B-hydroxyalkylphenylsulfidesin moderateyield. The solutionof Bu,NF in THF shouldbe dried with 5-A molecularsievesbefore use. Yields are usuallv

2U

(Phenylthio)nitromethane

improvedby useof 1 equiv. of BuoNFin the caseof aryl aldehydessubstitutedby group. an electron-withdrawing

R ing- enlarged a-ph cnyII of I (2BuLi,THF/HMPT)ri (2 equiv.)to a-phenylthioc

Bu4NF,25"

tuCHO11JIl-*4t

cHCH2SC6H5 OH

1",

CH, + CoHrS-:lrJC

C6H5!CHrSC6H5

C.H,COCHT+| --

CuH,

/'cH2sc6H5 /\ * 1- N*-,.Q,, j_o"

(.e?.:

I F. G. BordwellandJ. E. Baru I S. Kim andJ. H. Park.Chcm

IA. Hosomi,K. Ogata,K. Hoashi,S. Kohra,and Y. Tominaga,Chem.Pharm,Bull''36, 3736(1988).

Phenylthionitrile oxide (1). Generationand trappingwith an alkene:

Phosgene. cis-Oxyamination of dh tion with phosgeneand then which cyclizeson treatmen Debenzylationfollowed by-h

I c6H6' N(qH')r-

cuHrNCo c6H5scH2No2+

[cuHrSC:N-+o] + cuHrNHCxncuH, I 30soJcH3(cH2hcH=cH2

\i-9 il

-

|

c.ursA4cor6 o

2

Br

'oH

l)ctrLxaJ 2)qH'cn t{rr 7rt

crc6!r.co1H \i-? il | e1% cuH,s^}coHn r ,

This route providesa two-stepsynthesisof 3-(phenylsulfonyl)-A' -isoxazolines (3). The phenylsulfonylgroup can be displacedby variousnucleophiles.r

I J. Das,Syn.Comm.,ft. 9(}?(

I D. P.CurranandJ.-C.Chao,,I. Org.,53,5369 (1988)' (1). (Phenylthio)nitromethane,C6H5SCHTNO, Preparation': l) KoH

{

iiscuH,* NorcHrcooc ,s, 2#

|

Phosphines,chiral. H y drogenation catatyto: have been developedfor sc aminoacidprecursors,includ and the novel ligand3. in ri hasbeen usedas a Rh(I) co

phosphines

a:c trf aryl aldehydes substituted by

26

^ ,Ring-enlarged a-phenyrthiocycroarkanones.2The adducts(2) of the dianion of I (2BuLi, THF/HM'r) with cycloarkanones rearrangein the presenceof Arcl. (2 equiv.) to o-phenylthiocycloalkanones.

vcHCHrSC6H5 OH

i"'"'

CH, I

CHr+ C.HTSC:NO,-

l.H.ccHrsc6H5

85%

OH

o tl

74qo ft-scrH, ",n5cn,

I

CuH,

l H .r . C

HO _ CHNO, 2Arcr, > (,}"", CuHt t

/,cH2sc6H5

lF. G. Bordwelt andJ. E._Barrmess, J. Org.,43,3l0l(197g). I S. Kim andJ. H. park,Chem.trttru, tii flqs8i.

-oH

I,,minaga,Chem.Pharm.\uil..36.

ot l

Phosgene. cis-Oxyaminationof alkenes.t trans-1,Z-Bromohydrins . on consecutivereac_ tion with phosgeneand then benzyramine are convertedinto a bromo carbamate, which cyclizeson treatment with NaH (2 equiv.) to a cls-oxazolidinone.NDebenzylationfollowed by hydrolysisp.ouid", a crs_1,2-amino alcohol.

SC:N -rOl + CuHrNUCuuCuH,

Bzl

I t +

t H3(CH2)3CH=CH2

V"'o"

llff:iiilif',ft'' 73%

'#'f

I

A

N,.

".- (r" oFo

V...o"o*"r,

,ooJr,, "",

CoE : C-

HCI THF qumL

I' rhenylsulfonyl)-ALisoxazolines I r.rriousnucleophiles.'

"o!o

' J. Das,Syn. Comm.,lg,907(l9gg).

:

KOH \H,OH 92%

Phosphines,chiral. Hydrogenation catarysts. A numberof new opticalryactivephosphinerigands have been developedfor selectiveenantioserective reductionof N:c bonds of aminoacidprecursors,includingDpCB(l)r, the methylenehomolog(2), of dipamp, and the novel rigand3, in which the sourceof chiralityis a Re uton.,.,e ligand4 hasbeenusedas a Rh(I) complexfor hydrosilylation.a

I D. P. Simmons, D. Reichlin,andD' Sku'v'I

Phosphoric acid

o-CH.OC.H....

(CuHJrq.

/P1 c.H,-

(CrH,)rP!

CuHt.. "p-J /

)

I (DPCB) o-CHTOC$/

!",

,

(CrH,)rP-(A)

P...rtc,H,), (c.Hr)f/Re\No 3

.."ro'l-

dl Phosphorusoxychloride (Phosphoryl studit early Although Dehydration. lit shownto involve an anti-elimination' (Z)-alke (E)or of appliedto preparation and i "t tg> and (Z)- A22-or A2lsterols' trisubstitur of alkenesfor isomerization

CHt\or)\/

: CuH,

CH' -s-!

4

,T.Minami,Y.Okada,R.Nomura,s.Hirota,Y.Nagahara,andKFukuyama'chem' (1986). Letters,613 'C. R. iohnsonandT' Imamoto,l' Org'' 52,2170(1987)' chem.,lnt'Ed.'26, andJ.A. Gladysz'Angew. 3B. D. Zwick,l. M. Arlt, A.-i. puuo"n, 910(1987). 'A. F. F. M. M. Rahman andS' B' Wild,tbtd"39' 155(1987)' Phosphoricacid. The enol acetate(2) Cationic olefin cyclizationof aldehydeenol acetates't ofcitronellal(l')undergoescyclizationtodihydrocyclocitral(3)inthepresenceof

CH, A, CH,

o

I J.-L.Giner,C. Margot'andC' Dlerass

CH.

H

KOAc, AcrO, N(CrH), 80%

,

A z', I CH,l \

cH,

3 = 18:1 49-52Vo (translcds) SnClo,CHrClr, " = 16:1 42Vo 0o cH"so"H, c6H5CHr' " e.l 8o4a H"Po";c.HrCH3,1o0"

2 G I Z= 2 : t )

eitherLewisorBrdnstedacids,Cyclizationisachievedinthehighestyieldwith obtainswith Lewis acids, g57oaqueousphosphoricacid. Hilher stereoselectivity of 4 to the drimane 5 is but the rate is slower, and the yiJtd lower' Cyclization provides5 in I4Vo yield' best achievedwith Snclr. In this case,use of H:PO4

PhosphorusPentoxide,P2O'' 1' i-A^fno'6-arylaminoPurincs' p be can haveusefulbiologicaleffects' and P with an arylaminehydrochloride

o tl

rlr HrN

ANt

N

)

* *ttq

N H

I

R=C.}l R = p-FQ p =;-Cll

OAc ..CH,

I E.-S.M. A. Yakout,H' M Soe'and E

4 (Elz= 2:r)

PhosPhorusPentoxide

267

I D. P. Simmons,D. Reichlin, and D' Skuy, Helv',71, 1000(1988)'

Phosphorusoxychloride (Phosphorylchloride)' POCI.' were iehydration. Although earlystudiesof dehydrationof tertiaryalcohols been has shown to involve an anti-elimination,little use of this stereoselectivity

9",

.,"ro'1ff

appliedtopreparationof(E)-or(Z)-alkenes.Thisreactionisusefulforpreparation of oi (n)- and (Z)- A22-or An-sterols,and in combinationwith syn-hydroboration alkenesfor isomerizationof trisubstitutedsteroidalalkenes''

\ CHr\,OrA-y' /* .P(c,ur), tt-ao CuH, 4

\riahara, and K. Fukuyama,Chem.

,,u,J*',,.,

l'vr- 1

Int. Ed.,26, Angew.Chem., C;.,'Jvsz.

CH,

l r : r1 9 8 7 ) .

CH,

ol acentes.t The enol acetate(2) !r ,i.'clocitral(3) in the presenceof CH'

o \ : -.----, ;

3 = 18:I :9 -524o (translcis) " = 16:I 42Vo C" " =8:1 8 0 9 o O , :;:reved in the highestYieldwith e .:;:rvity obtainswith Lewis acids, lr;.izationof 4 to the drimane5 is H PO. provides5 \n l4Vo Yield. Cll.

rJ.-L.Giner,C. Margot,andC' Djerassi,J. Org',54'369(1989)' Phosphoruspentoxide,P2O.. i-Amino-6-srylaminopurines. Theseinterestingpurines(2)' many of which reaction haveusefulbiologicaleffects,canbe prepareddirectlyfrom guanine(1) by at 200''l (CrH')'N'HCl of presence in the PzO, and with an arylaminehydrochloride

N(qH,,

T\\

H,NAN

\,+\ ",*A*Ail' NHR

o + RNHT.HCI

t'o'

,

I R = CoHs p = p-FC5II R = m-CH:Cell

SOVo 6l7o 82Vo

I E.-S.M. A. Yakout,H. M. Soe,andE. B. Pederson, Acta Chem'Scand''B,42'257(1988)'

26

Platinum(IV) oxide

Caution: explosiveand toxic. Picric acid (2,4,6-trinitrophenol). Picrates.r At one time organicbaseswere isolatedand identifiedas the picrates,which are often highlycrystalline.Picricacidis generallysuppliedas a moist solid containingwater, which hinderscrystallizationof picrates.The water can be replacedby ethanolfor storage.Picratescan be preparedby reactionin acetone, in which picric acid is fairly solubleand then allowedto crystallizeby addition of ether.

Polyphosphoricacid trimelhylsilyl cstc

(1). Preparedas a mixture of four col in CHrCl2.Solublern t methyldisiloxane It efiectsa synthesisof amidinesfron

I D. LloydandH. McNab,J. Chem.Res.(S),18(1989).

(PDB), 1-Piperidino-3,3-dimethyl-2-butanol

I D. W. Cameron,G. I. Feutrill.and P. G (

* / - - \ (CH3)3CCHCHTN / |

(1).

\___J

OH

+ C.H.N{ C6H5COOH

I wittr piperidine The B-aminoalcoholis preparedby reactionof (CH3)3CCCU,Br acid followed by reductionwith LiAlHa. Resolutionwith ( - )-dibenzyl-t--tartaric provides(-)-1, oo -72" (98Voee). Enantioselective addition of (C{IslzZn to C,II'CHO.I In the presenceof ( - )-1, diethylzincaddsto C.H.CHO to providethe (R)-adduct.The opticalpurity of the catalyst(1) has a marked efiect on the rate and also on the optical purity of the adduct.Thus (-)-PDB of only l0-20Voee provides(R)-l-phenylpropanol in 80-90% ee and about 95Vochemicalyield. This nonlineareffectin catalyzed asymmetricoxidationsand aldolizationshas been noted previously.2It may be a resultof the molecularityof the reactionor of the aggregationor ligandexchange of the catalyst. ' N. Oguni,Y. Matsuda, Am. Soc.,1f0,7877(1988). andT. Kaneko, I C. Puchot,O. Samuel, E. Dunach,S. Zhao,C. Agami,andH. B. Kagan,Am. Soc.,l0E, 2353(1986). Platinum(IV) oxide (Adam's catalyst,1, 890). 1-Deoryanthracyclines.r Hydrogenation of anthracyclinesla or lb catalyzed by Pd/BaSOagives7-deoxy-l(97Voyield), which on further hydrogenationis converted into a 5,7-bisdeoxyproduct. However, hydrogenationof I catalyzedby Adam'scatalystin methanolcontainingchloroaceticacidaffordsthe 5-deoxyproduct 2 in aboutTIVoyielc.

This reagentis both a Lewis aod of sulfoxidcrr Pummererrearrangement via an epoxide.2 OH

I

(c^H.)"cH-cH(c^H.),t.r,l.'i.

l - " -

OH

800 150"

I S. Ogata, A. Mochizuki, M. Kakimoto. e

( le86). r M. Kakimoto.T. Seri.andY. Imai.ibrd. t

Potassium. Demethoxylation.t 1-Alkyl-3.{.>t on trealn alkyl-3,5-dimethoxybenzenes sodium or potassiumcan be used to t zene(85% yield). dimethoxyben

o

o o H cocH,R

l(TU

"oH

OH

c

O Sugar

la,R=H

rb.R=OH

o )

O Sugar

ocH3 r u . Azzena,T. Denurra, E. Fenude.G.

Il

Potassium

269

rD.W.Cameron,G.I.Feutrill,andP'G'Griffiths'TetrahedronLetters'29'4629(1988)'

fe ,rndtoxlc. rL:cJ .rndidentifiedas the Picmoist r. rcnerallysuPPliedas a be can water n .,t ni.rate.' The acetone' in rcl.rrcd bY reaction of ,".i ,,, .rYrtullizebY addition

f/s \l) l{ il

ester(PPSE)'(cH')rsio-k$-o7f-lstttn"' acidtrimethvlsilvl Polyphosphoric

l_ ositctti,l, of PtO' with hexa(1). Preparedas a mixture of four componentsby reaction solvents'l aprotic in CHrClr. Solublein most methyldisiloxane It effectsa synthesisof amidinesfrom simplecarboxylicacidsand amines':

I

:1{ cqHcH,N I OH

)

(1)'

NC.H.

r-----v

o

ll I r ( I I,).CiCHrBr with PiPeridine acid rrlh ( - )-dibenzyl-r--tartaric

c.H,[r'mc'u'

+ cuH,NH, c6H5cooH ffiff'

agent' Thus.it effects This reagent is both a Lewis acid and a dehydrating pinacolto pinacolone of rearrangement and pummererrearrangement of sulfoxides via an epoxide.2

In the Presenceof (fl,CHO) f,. *t-uOOu.t'The oPticalPuritY ,,. .,n,.talso on the oPticalPuritY r rr,,, ides (R)-1-PhenYlProPanol catalYzed Tl'- nonlineareffectin It maYbe a Bnrrrtcd previouslY'2 exchange h. r{gregationor ligand -rr7 (1988)' 'Kagan' llo Am' Soc'' 10E' ,"] .,"0H. B

La or lb catalyzed ri .,nthracyclines is conch ''n further hydrogenation bY catalYzed 1 of . hrJrugenation prod5-deoxy the *.,,. o."idaffords

o T"

I

H ^"

* c6Hid-c(c6H5)3 cuH,

617a

800 1500 I S. Ogata, A ( 1986).

lol

o

(ctlcr)r c'Hs-f\'tu't ) (c6H5)rcH-qH(c6H5)2 I c6H5 OH

26Vo 977o

Soc'Japan' 59' 2171 Mochizuki, M. Kakimoto, and Y' Imai' Butt' Chem'

: M . K a k i m o t oT, Seri.and Y. Imai, ibid.'61,2643(1988)

Potassium. Demethoxylation.tl-Alkyl-3,4,5-trimethoxybenzenesareconvertedintolon treatmentwith potassiumsand in THF Either alkyl-3,5-dimethoxybenzenes sodiumorpotassiumcanbeusedtoconvertl'2'3-trimethoxybenzeneintol'3(85% Yield)' dimethoxvbenzene

K. THF, 20" '12-81%

O Sugu

ocH3 28 (1989). G' Melloni'andG Rassu,Syntftesis, T. Denurra,E. Fenude, Azzena,

270

Potassium3'aminopropylamide

Potassium-l8-Crown'6. in THF cleavageof p-lactones.r The blue solutionof potassium-18-crown-6 protonation on -20" (1) which to furnish a dianion cleavesB-propiolactoneat usedto obtain givesmethyl acetate.A similar reactionof the p-lactone2 canbe isopropylproPionate(3)-

.

o

o

.

f

r

-@, x'l)-ocr,@# cH,E-ocH,

A"

Potassiumt-butoxide. Haller-Bauer reaction.t A studl o activetertiaryc-phenylketone(l)'stx with metal amidesin benzeneand all<

o

i l ^ c,H,*cH'cH:c(clt) .crH, cH.(R)-(-)-l

CHr'

inversionin reactionswith KOCH'CH (88% retention)obtaim rn eoselectivity is ineffective.The cation reacti\-itl-thus Substantiallythe sameresultsare d cr-phenylketone (+)-3.t In this casc t

l

'*f.",' o cH,[-ocqcu,

'1119 3 ---zo c2H5c-ocHCH3

LI

+

cH,'

cH,

cuH,.

t'"'l4J/YC($ o (R)-(+)-3

Diphenyl ethersundergo C-O bond Cleavageof aryt ethersand esters'2 give phenolsand benzene'Phenylbenzoates cleavagewith this reagentin THF to is Lond' and the rate of this ester cleavage are cleavedat the carbonyl-oxygen groups'OCH' and OH' in eitherthe acid markedlyincreasedby electron-donating or the PhenolgrouP' 1261(1988)' andA. Mit-i"l-"1:i;9:* chem'comm'' , 2. Jedlinski, M. Kowalczuk, (1988)' 5230 53' 'n. ff. fi.n andJ. W' Dupon,l Org'' (KAPA)' Potassium3'aminopropylamide from secPropynyl etherscan be obtained nOCtt"C=Ctt' ROC:CCH.+ by dehydrochloriwith trichloroethvlene followed ondary alkoxides uv ,Ju.t-J ethersby KAPA' propargyl can be 'earanged to nation and methylation'These alcohols'' to highly hinderedsecondary This sequenceis appUcaUie

benzeneproceedswith 98Varetentlon torial isomers5 and 6 is different fron with retention (84-86Vo)by KOC(CH

O:eC.lt I

/Yc.q

(CH3)3CJ..-\t/

5

essaryfor cleavageof 6' whereas6l ho of 5, cleavagewith LiNHz resultsin i (7( samebaseproceedswith retention Cyclic enediYnes'aA Ramburg-l nishescYclicenediYnes'

clr, I) KH 2) cLc=cHcl

c-CuH,'OH #

c-C.H,,OC=CCH' ff

c-cuu,1ocH2c=cH

707(1988)' Serratosa'Synthesis' rC. Almansa,A' Moyano'M' A' Pericas'andF

o"s

(cllrl

r,7 z-s

Potassiumr-butoxide

r,l ir()tassium-18-crown-6in THF [ . 1 ' r r , n( l ) w h i c h o n p r o t o n a t i o n 3-,.r.tone2 can be used to obtain

271

Potassium/-butoxide. Haller-Bauer rcaction.t A studyof the base-induced cleavageof the optically activetertiary o-phenyl ketone (l)' shows that cleavageproceedswith retention with metal amidesin benzeneand alkoxidesin an alcohol or benzene.but with

o ^

o ll

' CHrC-OCHr

tl

C.H.\/CHTCH:C(CH,), -C.H, CHr-

H _ CH'CH:C(CH3),

cnf"'c.n, )

(R)-(-)-l

inversionin reactionswith KOCHTCHTOHin ethyleneglycol. The highestster(887oretention)obtainswith potassiumr-butoxide.Lithium r-butoxide eoselectivity is ineffective.The cation reactivitythus is K* ) Na* ) Li'. Substantiallythe sameresultsare observedin the cleavageof the cyclopentyl ct-phenylketone (+)-3.'In this casethe reactionwith potassiuml-butoxidein cll,

",rf,'Wc(c*)' ",Wc(cHJ'

IHCH,

o

cl{

(S)-(+)-a

(R)-(+)-3

hcrrl cthersundergoC-O bond Phenylbenzoates rr.. .riltlbenzene. | :hc rate of this ester cleavageis 5.( )('Hr and OH, in eitherthe acid t i t , ' n t .C o m m . , 1 2 6 1 ( 1 9 8 8 )

benzeneproceedswith 98Voretention.However,cleavageof the axial and equatorial isomers5 and 6 is differentfrom that of acyclicsystems.Both are cleaved with retention (84-86%) by KOC(CH,),, but only a 2-hour reactiontime is nec-

O:CC.H,

f9c,n, (CHJ3CJ:------/

?rH,

fYqcuu, (CH3)3CJ:-----J

l\\

r. rthcrs can be obtained from sechr .ne followed by dehydrochlorigrJ to proPargYl ethers bY KAPA' .(.()ndary alcohols.t

essaryfor cleavageof 6, whereas64 hoursis requiredfor cleavageof 5. In the case of 5, cleavagewith LiNH, resultsin inversion(10%), but cleavageof 5 with the samebaseproceedswith retention(70%). Cyclic enediynes,aA Ramburg-Backlundreactionof the cyclicdiynesI furnishescyclicenediynes. clt

t ;.t

c-C.H,,OCH'C=CH

707(1988)' Synthesis, .::.:r()5a,

J

,/ O.S -

\:i

-\ (CH^l.

I,n=2-8

KOC(CH.), -----+ 20-80qo

nZ

Potassium ffuoride--1E-Crown-6

'K. E. HamlinandW. A. Weston,Org. React.,9,1(1957);E . M. Kaiserand C. D. Warner, Synthesis, 395 (1975). 2 L. A. Paquetteand J. P. Gilday,l. Or9.,53,4972(1988). I L. A. Paquetteand C. S. Ra, lbid.,53,4978(1988). { K. C. Nicolaou, G. Zuccarello,Y. Ogawa,E. Schweiger,and T. Kumazawa,Am. Soc., 110,4866(1988).

(crH5)3SiO

.\ t

\./v

t

(cHso.c.tL l

Potassiumfluoride. Fluorination Freeze-driedKF caneffectchloro-fluoroexchaneein refluxins DMSO.'

cl-c6H4No, tp

F-c6H4No,

I Y. KimuraandH. Suzuki,Tetrahedron Letters,30, 1271(1989). C:llt-..u

Potassiumfl uoride-18-Crown-6. 13+ 2lAnnelation. Cleavageof l-(trimethylsilyloxy)-2-alkoxycarbonylcyclopropanes(1) with KF-18-crown-6generates^y-oxo-a-ester enolateanions,which can be trappedby electrophiles.Trappingwith a vinyl phosphoniumsalt resultsin (2).' [3+2] annelationto provideannelatedcyclopentanones

J. P.MarinoandE. Laborde.l.On . :J. P MarinoandJ. K. Lone. Am io(

.",afffi, Lhr

cr

(c.HJ.rcH=CH,Ba ---:--:-:-------

l

80%

H" I

Polassiumfluoride-Hydrobromk r Desilylation of phenolic crtcnphenolsrequiresBuoNFor HF (for lation can be effectedat 25" with KF

.t,oC-oSi(cH),-r-t

fi{Q cooc2H5 ,

Octahydronapthalene synthesis.2An intramolecularversionof this annelation usinga Michaeladditionto a vinyl sulfoneprovidesthe octahydronapthalene unit (1) of compactin(2), a mevinic acid of interest as an inhibitor of cholesterol synthesis.

A. K. Sinhababu, M. Kawase, andR

Potassiumpermanganote. Imines --+ nitrones.r This o'd transferconditionsin aqueousCHJ BuoNClor (r-CrH,r)oNBr.

Potrssiumpermanganate : I \1. KaiserandC. D. Warner,

(crH5)3SiO

(c,Hs)3sio ./cooc2H5 /-CHSO2C6Hs

I ir

-^i'

-.-CHSO2C6H5

-N"CHCO,C,H.

Am. Soc., rJ T. Kumazawa,

o- iluoro exchangein refluxing

l.\o.

r. r\9)

lr ..,r r )-2-alkoxycarbonylcyclo(r-(\tcr enolateanions,which rr. rhosphoniumsaltresultsin o r . ' .( 2 ) . r

2 ' J. P. Marinoand E. Laborde, J. Org.,52, I (1987). rJ. P. Marinoand J. K. Long, Am. Soc.,ll0, 7916(1983).

(c6Hr)!PCH=CtlzBa

-

80%

lr""t'l

Potassiumfluoride-Hydrobromic acid. Desilylation of phenolicethers, Desilylationof l-butyldimethylsilyl ethersof phenolsrequiresBurNF or HF (for a base-sensitive phenol).Actually this desilylation can be effectedat 25" with KF combinedwith a traceof hydrobromicacid.r CH3O)U\aOSi(CH,),-r-Bu | t \./

|

-

-

-

CH3Oy\.OH 2KF,DMr,25. -

- + e3so

|

|

| \2

A. K. Sinhababu, M. Kawase, andR. T. Borchardr, (19g9). Synthesis,7l0 lrulrr versionofthis annelation unit I rhc octahydronapthalene a. an inhibitor of cholesterol

Polassiumpermanganate. Imines --->nitrones,r This oxidation is possiblewith KMnO. under phasetransferconditionsin aqueousCH2CI,in 15-90Voyield. The best catalysrsare BuoNClor (n-CrH,r)oNBr.

n4

Potsssiumpersulflte

C.HTCH:NC(CE),

o ll

* .,c(cH3)3

Ylo;l"l;X'' ..j]:%%: C.H,CH:N'

+C.H.CNHC(CH3)3

\o-

I K. Shimamoto and Y. Ohfune. Tetrahcd r C. S. Pande and N. Jain, Svn. Comtn . I

,r,a\ (89Vo) 2-Hydroxy-3-oxocarboxylic esters.2 B-Alkyl-a,B-unsaturatedesters (1) are oxidizedto theseesters(2) by KMnOo in mildly acidicaqueousacetoneat 10" in 60-857oyield.

Potassiumsuperoxide,KO:. Arene oxides.t KOr convertsl-n sulfurradicalthat effectsepoxidationr solventsat -30'. Anthraceneis conr l(

CHrCH:C-COOCH3 I CH,

o tl-,C

CH.C -::--' - , / 8 0 %

\

I

\./

;- COOCH,

ct

OH

CH, )

I

rD. Christensen J. Or9.,54,126(1989). andK. A. Jorgensen, r D. H. G. CroutandD. L. Rathbone, (1989)' Synthesis,40

PotassiumpersulfaterK2S2O{i. Benzylic oxidstion (11, 441).' Oxidation of the N-Boc-L-tyrosine1 with with cuSo, as catalystgives the syn-cycliccarbamate2, which can be K2S2O8 convertedto the p-hydroxyamino acid 4 as shown. O-C:O

Desulfuration 2 Thioamides arc (13,260).The req tassiumsuperoxide caseof N-(2-hydroxyphenyl)thioam vield.

cHroAc rff-acH'oAc i

l

|

NHBoc

KS,o.,cuso. 76qo

cH.o)V

S

Hll

' cHro

NCC6H5

I ty na1oul, l0o7o B@,o I2)

OH

' H. K. Lee, K. S. Kim, J. C. Kim and \' :Y. H. Kin, Y. I. Kim, H. S. Chane.and

\ cH3o

4

OH

COOH

l) Po,, q 2) TFA ra459o

cH3o

o + 4KO, -

2 (37:l)

3

RCOOH -'+ RCOOOH.2 This oxidant convertswater-insolublecarboxylic acidsto the peracidin ether or CHrCl2under the influenceof benzyltriethylammonium chlorideor polyethyleneglycol (PEG-400).

Pyrazinium chlorochromar". f ) \'/ H yield pyrazine by reaction of in ( 80Vo of alcohols. The rea Oxidation alcohols.'

Pyrazinium chlorochromste

o tl

/ - t H r

+ C6H5CNHC(CH3)3

275

' K. Shimamotoand Y. Ohfune, TetahedronLetters,29,5177(1988). ' C . S . P a n d ea n dN . J a i n ,S y n .C o m m . , 1 8 , 2 1 2(31 9 8 8 ) .

(IIVo)

esters(1) are .e-unsaturated rJr. aqueousacetoneat - l0'

Potassium superoxide, KO2. Arene oxides.t KO, converts 2-nitrobenzenesulfonyl chloride into a peroxysulfur radical that effects epoxidation of polyarenes to give arene oxides in aprotic solvents at -30". Anthracene is converted into the 9,I0-quinone (70Vo yield).

foct

[^rno' \r'

4'\

I _=+_%(Y

-coocH" -( '.. /

,Ko,

OH

ll

"r-<J

:

o

a

9


---------) 955"

rhc N-Boc-l-tyrosine1 with c ..lrbamate2. which can be

Desulfuration' Thioamidesare known to be convertedinto amidesby potassiumsuperoxide(13,260).The reagentcan alsoeffectcyclodesulfuration in the caseof N-(2-hydroxyphenyl)thioamides to providebenzoxazoles in generallyhigh yield.

cHroAc S NH 2 (37:l) I l) Ba(oH)1

t00Eo B@,o ID

OH

,/\Y'&CooH l l l NFIBoc \2 3

Hll

G*tu"'

* o*o,' #..*

G>cuH,+

K,Soo

I H. K. Lee, K. S. Kim, J. C. Kim and Y. H. Kim. Chem.Letrers,561(1988). rY. H. Kin, Y. I. Kim, H. S. Chang,and D. C. Yoon, Heterocycles,29,213 (1989)

-ClCrO,

Pyrazinium chlorochroma n, a

\fr

(1). The reagent is obtained in

H

carboxylic n. \\ater-insoluble amn:lurnceof benzyltriethyl

80Vayield by reactionof pyrazinein 6M HCI with CrO.. Oxidation of alcohols, The reagentis comparableto PCC for oxidationof alcohols.'

n6

Pyridiniump-toluenesulfonate

I G . J . S . D o a d , J . C h e m . R e s .( S ) , 2 7 0 ( 1 9 8 8 ) .

Pyridinium bromide perbromide. can be obtained in a-Bromo-arp-enones.r cr-Bromo-a,B-cyclopentenones with this reagent(about 3 equiv.) and good yield by reactionof cyclopentenones pyridine(3 equiv.) in CHzClz.In the absenceof pyridine,yieldsare lower because of polybromination.

a

o

o

Py.HBr.Br. PvrcH,CL

R

R = CHr R = CHzOBzl

A-_",

q

Quina alkaloids. Ch iral sulfinates, (CH. ).C5(O by reactionof r-butylmagnesium I carriedout in the presenceof an op active.The highestenantiosele.c with (-)-quinine (1). Examole:

R

(PrO)rS:O + r-&

57Vo 86Vo

' W. G. Dauben Syn.Comm.,lE, 1323(1988). andA. M. Warshawsky, Pyridinium chlorochromate(PCC) 1,2-Diketones.t Alkyl benzylketones(L) are oxidizedby PCC in combination (2) in 80-85Voyield.This oxidationfailswith dialkyl with pyridineto 1,2-diketones ketones.

+rcc ffi c5H5cH2coR

Asymmetric redaction of trlct with quinidine(1) asa proton sour of HMPT increasesthe rate and tl

o il

o o

c6Hr-c-ccrl

c.n,l-[n

o

ll

I (R = CH,, CrHr) I F. Bonadiesand C. Bonini, Syn.Comm.,18,1573(1988).

Pyridinium p-toluenesulfonate. Selective cleavage of t-butyldimethylsilyl ethers, This reagent cleaves t-butyldimethylsilylethersat 22-55' in 80-92Voyield in the presenceof l-butyldiphenylsilylethers. rC. Prakash,S. Saleh,and I. A. Blair,Tetrahedron Letters,30,19 (1989).

' J. Drabowicz,S. Legedf. and !1. Mrl r S. Takeuchiand Y. Ohgo. Chem Ia

en:.:t()nes can be obtained in tr. r'..rg!'nt(about 3 equiv') and ir:.irrc. f-ieldsare lower because

o ll

\

-Br

t'

R

Quina alkaloids. can be prepared Chiral sulfinates,(CH3)3CS(O)OR.' Alkyl r-butylsulfinates chloride with dialkyl sulfltes.If the reactionis by reactionof t-butylmagnesium carriedout in the presenceof an opticallyactiveamine,the productscanbe optically active.The highestenantioselectivity is observedwith aminoalcohols,in particular with (-)-quinine (1). Example:

(CH3)3CsoPr

@rO),S:O+ r-BuMgCl #

o (R,747o ee)

. l r r . r l 3( l 9 8 t t ) .

I ,.rrJrzedbYPCCin combination d I hr. oxidationfailswith dialkyl

Asymmetricreductionof benzil.2 Reductionof benzilwith SmI,in C.H./THF with quinidine(1) asa proton sourceyields(R)-benzoinin about40Voee.Addition of HMPT increasesthe rate and the enantioselectivity to 56Voee.

o ll

.

:.

tvrs

l

o o l l l

C^H5C-CR

I

I ethers. This reagent cleaves i rrcltl in the presenceof r-butyl-

1 . ,: : ." . 3 0 , 1 9 ( 1 9 8 9 ) .

o

stnl. I,

ll

C6H5-C-CC6H5 + i

o

tl ll

uMr

l

o

.

C6H5C-CHC6H5 l

H

(R,567oee) I J. Drabowicz,S. LegedZ,and M. Mikolajczyk,Tetahedron,4,5243 (1988). rS. Takeuchiand Y. Ohgo,Chem.Letters,403 (1988).

propane,which rearrangesreadi\ pane(2) canbe isolatedin the cas by a l% H,SO. solutionto the ke

t'"'*+No2

(cHJ'rcHoH ) "'"'*+NH'+

o

a-\--n

Raneynickel (1). Transfer hydrogenation o;f nitroarenes.r Transfer hydrogenationof the nitroarene2 with Raney nickel and isopropanolas the hydridedonor resultsin the

9oA1cH;,J*x,

(ct[)'c:o

*#Fu,*ON:c(cH{

A typicalreactionis formulate amine5, formed via the unstableimine 4. Other alcoholscan be used,but increase in the bulk resultsin lower yieldsof the final product. A similarresultobtainson transferhydrogenationof 2 with Pd-HCOOH in the presenceof isobutylmethyl ketone (equationI) to provide6.

rv orr

tt' C\,"H2),cocHN2

cHrr

r.su)c=o'p*c, o 2-1g9i999r,3 F",*-G.:.(::l xcmx rm* Jearc,

.,",*eFfi-E{:, 6

p-Lactams.2 Decomposition with Rh,(OAc), in refluxingbenec acetylgroup on the diazo carbon i bond ratherthan reactionof the ce

o (cH3)3c\ lL -coc -Ntl

Brl/" I A. A. Banerjee (1988). l.C.S.Chem.Comm.,1275 andD. Mukesh, Rhodium(Il) carboxylates. Cyclopropanationoffuranyl diaZo ketones.r The reactionof o-diazo ketones of furanylpropionicacidswith Rhr(OAc), involvesformationof an unstablecyclo27E

N. I

rsalsoessentialfor high yields.Ins over insertion into a 1-C-H bon rhodium(Il) benzoateas caralvsr.

Rhodium(Il) carboxylates

2T,

propane,which rearrangesreadily to a cyclicketone.The intermediatecyclopropane(2) canbe isolatedin the caseofthe diazobenzofuran1 andcanbe isomerized by a lVo H'SO, solutionto the ketone3 or rearrangedthermallyto 4'

of the nl1r.rnsferhYdrogenation in the results donor ,. the hYdride

I

rro" I---rr"1

(cH')'c:o

,..nONH,+

'[o,*O*:",t*'] 4 increase (l:r;r alcoholscanbe used'but [:..' rroduct' Pd-HCooH in the ;r,'..^;i;" of 2 with t r r ' : r I ) t o P r o v i d e6 '

A typicalreactionis formulatedin equation(I)'

&!?'lil" t"(\,.H,),cocHN2 lW]

-'

S"" o

[,''"+*:'(::1 '*'" I *""' "t*n *

l-\

4 \7cH' t.rr.ru{ ) " t-"u-, \-./ 6 ' h ,"

( o t n m, 1 2 7 5( 1 9 8 8 ) '

of a-diazo ketones t Letttnes.t The reaction cycloformation of an unstable :. .'';';i".t

(1) p-Lactams,2 Decompositionof N-benzyl-N-t-butyldiazoacetoacetamide yield. The 2 in 98Vo xitrr Rh,(oAc). in refluxingbenzeneresultsiq the B-lactam g-C-H rcetyl group on the diazo carbonis necessary'forthis insertioninto the group t-butyl The ring' aromatic bondratherthan reactionof the carbenewith the

o *%l{"",""'l- ' to Rh'(oAcL ? tcH,),c--NA.cocH3 | -r. e8% Bzr/

Jt, t

c.Hr"'-N-.c(cH3)l 2

favored rsalsoessentialfor high yields.Insertioninto a B-c-H bond is generally of a use r)\,erinsertion into a 1-c-H bond and can be further enhancedby rhodium(Il) benzoateas catalyst.

2E0

Ruthenium(Ill) chloride-Tributylphosphite

I K.-T.Huh,Y. Tsuji,M. Kobayashi. F.O\ud..

o

.

(,-P,),N\H---* *" N,

Rhr(OAc)o Rhr(OCOAT)4

cHr't-N\pr

ffo

Ruthenium tetroxide. RCHrNH2 + RCONHz.| The tramf, can be effectedby oxidationof N-Boc alkl eratedin sitrzfrom RuO, (catalytic)and \ Deprotectionis effectedwith TFA in CH,t

cHrh*-*r-,

-i 4.2:l 6.2:l

95Vo

c-Sityl estersor ketones.s Decompositionof a-diazoestersor ketonescatalyzedby Rhr(OAc),,in the presenceof a trialkylsilaneaffordct-silylestersor ketones in 85-95Voyield. + (CrHr),SiH#-NTCHCOOCTH,

NaIO. ? C,H,CH,NHBo. C,H,iNIBoc I #

(czHs)3sicH2coocrHs + BocNH(CHr)rCHrNHBoc

Diazo ketone cyclization to hydroazulenones.a This reaction can be accomplishedin high yield under high dilution and efficientstirring to minimizebimolecularreactions.

#"oq @**:foql cHN,

L

'bl

I A. Padwa.T. J. Wisnieff,and E. J. Walsh,./. Org.,54,299(1989). : M. p. Doyle,M. S. Shanklin,S.-M.Oon, H. Q. Pho,F. R. vander Heide,andW. R. Veal, ibid., s3,3384(1988). 3 V. Bagheri,M. P. Doyle,J. Taunton'and E. E. Claxton'ibid',53,6158(1988)' r L. T. Scottand C. A. Sumpter,Org Syn',submitted(1988)'

Ruthenium(Ill) chloride-Tributylphosphite. N-Methylation of anilines.t This system activates methanol for N-methylation of anilines. RuCl.[P(CuHs):]. is more effective for N-methylation of N-alkylanilines.

G*,+

*o"Li"oP"", cH,oH $*,.n,,,* 807o

C6H5NHCH3+ CHrOH -+ RuClr/P(OBu[ RuClr[P(C.Hr)r] z

C64N(CE), 60Va 829o

GNHCH3 6Vo

Boc\}lt(

' K. Tanaka,S. Yoshifuii.andY. Nitta.Chca

Ruthenium tetroxide

' K.-T.Huh,Y. Tsuji,M. Kobayashi, F.Okuda,andY. Watanabe, (1988). Chem.Leuers,449

avo \ /

Ruthenium tetroxide. RCH,NII, --->RCONHz.I The transformationof primary aminesto amides can be effectedby oxidationof N-Boc alkylamineswith rutheniumtetroxide,generatedin sit, from RuO, (catalytic)and NaIO, (excess)in aqueousethyl acetate. Deprotectionis effectedwith TFA in CHrClr.

cH.|N-pr-: : J:.:z,restersor ketonescataf.,rJ o-silylestersor ketones

O Natol

C,H,CH,NHBo. C,H,iNTIBoc # ff

BocNH(CHr)rCHrNHBoc

Thr. reactioncan be accomIt .:rrringto minimizebimo-

.e s 9 ) . r J.'rHeide,andW.R. Veal, : . s 3 .6 1 5 8( 1 9 8 8 ) .

for N-methYlar:.. methanol of N-alkYlh.r \-methylation

i,cH,r,+( \:./

llrucH, 6Vo

c,H,coNH,

o

l. S:CH,COOCTH,

9^.

281

tl

;+

o

tl

BocNH(CHr)rCNHBoc ----+ H2N(CHJ2CNH2

I K. Tanaka,S. Yoshifuji,and Y. Nitta, Chem.Pharm. Bull.,*.3125 (1988).

-l

J Samarium(Ill) chloride. Pinacol condensationl This reaction can be effected with stoichiometric amountsof SmXr, which is not availablecommercially.The samereactioncan be carriedout with SmCl, a stableand relativelyinexpensivelanthanide,in catalytic reaction.Evidently,electroamounts(5-I0Vo) if conductedas an electrochemical species. active divalent the regenerate synthesiscan

Note that similar cleavageof I with sodium,which givesalmostp or the tr4r?s-isomer. Reductive cyclization.2 Red in THF/HMPT (20:1) at ff efec disubstitutedcyclopentenesvsteu high cis-anti-cis-stereoselectivin _ H

c

:1

CH. CH,

o

HO

l

, ll . --;_r8%,'.r. ntr, *"

OH

l

R,C _ Cl _ R " t l ^ 1 , R" R'

2 R'CR'

meso (+)

o!

I

Cyclopropanols,t Reaction o acid chlorides(1) resultsin doub cyclopropanering.

I E. L€onard,E. Duflach,and J' P6richon,J.C.S C h e m . C o m m . , 2 7 6 ( 1 9 8 9 )

2r:,a,COCt Samarium(Il)iodide. Cleavageof p-chlorotetrahydrofurans.r SmI2cleaveseither cis- or trans-P' (1) at reflux to give the (E)-unsaturatedalcohol chloro-cr-methyltetrahydrofurans (4) and (E)-enynols(6)' (E)-dienols provide 2. This cleavagecan

CI f<

(o4.,,

a > CH3 smrr.

/H

1s-.,%{l:;;t""

(4o."..,, t

Decarbonylation of a-alloty acid chloride with a ketone medu and liberationof CO. The necess SmIr.a

o il

I

O + CH,OCH,CC

cl /

\

-

\oAa":an,

)'0" CHr:9116t:CH(CHJzOH 4 (E' >97Vo)

u,p-Enones.s a-Haloketoncs o.B-enones(equationI). Praaical

3 CI /

2,Ei2

/

\ -o'

\

'c:cc5Hil

84qa

C5HrC=C - CH: CH(CHz)zOH 6 (E, >99Vo)

o tl

c.HrccHrBr

Samerium(ll) iodide

.,1:, be effectedwith stoichiometric The samereactioncan be nn-..rcially. rl', ::e rpensivelanthanide,in catalytic N::mrcalreaction.Evidentlv.electro-

Note that similarcleavageof c-alkyl-B-chlorotetrahydropyrans is best effected with sodium,which givesalmostpure (E)-unsaturated alcoholsfrom either the crs_ or the /rdlxs-isomer. Reductive cyclization.2 Reduction of the unsaturatedaldehyde r. with SmI, in THF/HMPT (20:l) at 0'effects a tandemradicalcyclizationof the trans-3,Sdisubstitutedcyclopentenesystemto a linear triquinaneunit (2) with surprisingry high cis-anti - crs-stereoselectivity.

cH.

! lr Jlc-5.

HO

o; t".1frilr., ""sB%

oH

J

. R C_C_R2

2

I

R- R, neso (+) ,

293

cyclopropanols.s Reactionof SmI, (2 equiv.) at 25" with 2-allyroxybenzoic acid chlorides(1) resultsin double cyclizationto tricyclic productscontaining a cyclopropanering.

:,,'r Comm..276 (1989)

cocr t

:nrll cleaves either cls- or trans'Ptr :.'give the (E)-unsaturatedalcohol | . , r J ( E ) - e n y n o l s( 6 ) .

li r('il,'.OH

OCH,CH:CH,

,nil!,"dx -;-\4",J

I

Decarbonylation of a-arkoxy acid chrorides. The reaction of an o-alkoxy acid chloride with a ketone mediatedby SmI, resultsin a r,2-grycol monoether andliberationof co. The necessary molarratiosare2:r:4, acidchloride/ketone/ SmIr.a

o

G".

rHF. ll CH.OCH"CCI + Sml,' -i1+

ll{('tt:CH(CHr)rOH 4 i >97Vo)

:=C -CH:CH(CHr)rOH 6 (8, >99Vo)

OH

53q"

cHrocH,

+ co

urp-Enones.s c-Haloketonesreactwith aldehydesandSmI,(l equiv.) to form c,B-enones(equationI). Practicallyno enonesform if 2 equiv. of SmI, are used.

o ll

f

t) Sm!,rHF

cuH,ScH,Br #

l

c'H'c:aH E, t00vo

Semicarbezide

'L. CrombieandL. J. Rainbow,Tetrahedron (1988);L. CrombieandR. Letters,29,6517 D. Wyvill,J.C.S.Perkin1, 1983(1985). 2T. L. Fevig,R. L. Elliott,andD. P.Curran, (1988)' Am. \oc.,110,5064 3M. Sasaki, (1988). Letters,29,6105 J. Collin,andH. B. Kagan,Tetahedron aldem,ibid.,29,4847(1988). 5\. Zhang,T. Liu, andR. Lin, Syn.Comm.,18,2003(1988).

N_N

N_N

"",{r\r-r4r\*,

Samarium(Il) iodide-Tetrahydrofuran-Hexamethylphosphorictriamide. Deorygenationof oxides.t Sulfoxides,sulfones,N-oxides,and phosphineoxides can be deoxygenatedby SmI, in THF/HMPT at20-65". HMPT is essential for high yields. 1Y.Handa,J. Inanaga, (1989). Chem.Comm.,298 andM. Yamaguchi,./.C.S.

rS. N. Mairi,M. P. Singh,p. Spevak. R G y (s),256(1e88).

(SeCN)r.Preparation.r Selenocyanogen, (13' 286) via selenocyanates of selenoaldehydes Selenoketones.2The synthesis selenoketones Electron-deficient of selenoketones. hasbeenextendedto a synthesis are simplypreparedby reactionof halideswith KSeCNfollowedby base-induced eliminationof HCN (equationI). However,this routefailsin the caseof precursors

Silica Hydroryisoxazolidines,t The rerto tonaldehydein methanolresultsin a minr and 2) in which the former isomer pred

X a

o) n'Ern'#

Ks"cN,

SeCN I

--+ CH,CH:CHCHO + C.HTCONHOH

Se ll

R'Cnn'-Yc'Ii5P'lP'

llB*'i'.

-ffi (rDcH3cHrsorcu",

/ \ H3C1o,:

lecN

cH,iHsorcuH, #

fr'

cH,cso,cuH,

groups.In this case,the selenocyanate is obtained containingelectron-accepting preparation with as shown for the cyanocuprates, reaction of selenocyanogen by (equationII). of phenylsulfonylmethyl selenoketcine TheseketonesundergoDiels-Alder reactionswith dienesto give selenopyrans good in to excellentyields. ' L. Birckenbach andK. Kellermann, &er.,58,786(1925). 2P.T. MeinkeandG. A. Krafft,Am. Soc.,110,8679(1988). Semicarbazide. Cleavageof disulfides.t Diaryl disulfidesare cleavedto thiols by semicarbazide in CH2CIr-CH3OHat room temperaturewithin 2 hours. Cleavageof di-

proceeds morereadily thanthatof diaryldisulfldes, disulfrdes heteroaryl

CH3OH,5-7 hr.60Vo SiOr,30 min.80-9OVo DEAE-cellulose, I hr. " 6 hr.95-98% Cellulose, 437o

I

markedlyincreasedwhencarriedout on ao i conductedon SiO, is completewithin 3O-{ only. Reactionsconductedon diethylaminc in a mixture of 1 and 2 in the early stagcsr Apparentlythis adsorbentcan convertI ifl itself has slight efiect on the rate and provil yieldand in the ratio 75:25. I I. A. Motorina,L. A. Sviridova, G. A. Golcb 30,117(1989),

2E5

o tl

I "ii- (1988);L. Crombieand R' N_N . llo s061(1988). z : : . , ' .2 9 .6 1 0 5( 1 9 8 8 ) .

TLNCNHNH,(r)

N_N

-----___----__< Ea%

.t./r\r-r{r\"r,

N_N

"r4r\"r,

: - \ \| flphosphorictriamide. oxe.. \-oxides,andPhosPhine [ ": ]0-65'. HMPT is essential tr'.( ,,mm.,298(1989).

(13,286) 1c.'.r ia selenocyanates E.r'.tron-deficientselenoketones Sc('\ followedbY base-induced u:e failsin the caseof Precursors

I, THF_CHpH

ct-<

)-s-s-{

\:/

\_/

\-cr ----l=--* 87%

zct--<

.FsH

\J

' S. N. Maiti, M. P. Singh,P. Spevak,R. G. Micetich,and A. V. N. Reddy,J. Chem. Res.

(s), 2s6(1e88).

Silica Hydroxyisoxazolidines,t The reaction of phenylhydroxamicacid with crotonaldehydein methanolresultsin a mixture of 3- and 5-hydroxyisoxazolidines (l and 2) in which the former isomer predominates.The rate of this reaction is

----+ CH,CH:CHCHO + C.HTCONHOH

F

I

-JoH

-K

Se tl Atqa

is obtained e. :he selenocYanate the for l. .r. shown Preparation II, \rrrh dienesto give selenoPYrans r:_< l:-\:).

re cleavedto thiols bY semicarbsrrhin 2 hours. Cleavageof dith.rt of diaryl disulfides'

/-1. HrC'\o,N\

. COC.H,

t CHpH, 5-7 hr.607a SiOr,3Omin.80-907o DEAE-cellulose, I hr. " 6 hr. 95-987o Cellulose,43To

-JcH'

11 tlo-\o,N-

coC6H5

2 95-98:2-5 100:0 60:40 4:96 75:25

markedlyincreasedwhencarriedout on an absorbentwithout a solvent.A reaction conductedon Sio2 is completewithin 30-40 minutesand resultsin formationof I only. Reactionsconductedon diethylaminoethyl-cellulose (DEAE-cellulose)result in a mixture of 1 and 2 in the early stagesand eventuallyof 2 almostexclusively. Apparentlythis adsorbentcan convertI into the more stableproduct2. cellulose itselfhasslighteffecton the rate and providesa mixtureof I and 2 in only modest yieldand in the ratio 75:25. : I. A. Motorina,L. A. Sviridova, G. A. Golebeva, andY. G. Bundel,Tetrahedron Letters, 30,117(1989).

2M

Silicon(IV) fluoride

Silicon(IV) fluoride, SiFo.The gasis availablefrom MathesonCo' Fluorohydrins.r These have usually been obtainedby reactionof epoxides with hydrogenfluoride at high temperatures.This reactioncan be carried at 0" or evenBuaNF. with SiFoin combinationwith a basesuchasdiisopropylethylamine In all cases,the fluorineatom is introducedat the more substitutedcarbon.Highest

Silver fluoride/Calcium ffuorilc. I a mixture of AgrCO,, HF. and Ce Fluorination r Alkvl bromd with this reagentin CH.CN (35-g effectedwith AsF/CaF. and l._L

C.HTCH:Cll.

) )o \si1cH,), c,.Hf 1

'o'1fi'";,.f;*"'"', ,) 80%

C,rHi

fluorinationof alkenesis possibk (-60Vo yield).

OH

-si(cHr), 2

68% KNts(cHJr1, J

CH'

il-

a

c,,n/-\n 3 oxiranessuch as 1. Reactionof the pyieldsare obtainedwith 1,1-disubstituted affordsa fluoroalkene. fluoro-B-silylalcohol2 with potassiumhexamethyldisilazide Desilylationof 2 with BurNF affordsthe correspondingB-fluoroalcoholwith retention of configurationof the C-F bond in about 75Voyield' 2-Oxazolines.2 Reactionof 1,l-disubstitutedepoxideswith nitriles and SiF. which oh further exposureto SiF. are converted (1 equiv.) providesfluorOhydrins, is attachedto the substitutedcarbon' In nitrogen the in which 2-oxazolines, into from reactionsconductedat 80o' to 81,Vo yield is increased the cited, example the

r T . A n d o ,D . G . C o r k M , . F u j i r aT. I

Simmons-Smithreagent. D iastereoselectivecyclory clohexanone obtainedwirh (R.R! stereoselective cyclopropanation r.l or (C2Hr)rZnand CH'I,, but rhe i the latter reagentin DME. Ttr c bicyclicalcohol3. The cyclopropa yield).

cH3...aY.c} o o H I

A

\-J I

C.H', t " "

c,H,,-+-N

'l:;N siF o"' !Lt"*, I' oF.n, ff;:--cH,oll 65ro

|

/

(1988); idem'ibid''t0'961 tM. Shimizu Letters,29,4101 Tetrahedron andH. Yoshioka, ( le8e). ) Idem,Heterocycles, 27.2527( 1988).

T. Sugimura,T. Futagawa,and A. Tr

Simmons-Smithreagent

:: ,m \IathesonCo. n ,'rtainedby reactionof epoxides Inr. reactioncan be carried at 0" or evenBuoNF. i:. :'rtrpvlethylamine h; :lrrrr€substitutedcarbon.Highest

n7

Silverfluoride/Calciumfluoride.AgF on CaF, can be preparedby evaporationof a mixture of AgrCO,, HF, and CaF, in water to a dry granularpowder. Fluorination r Alkyl bromidesare convertedto alkyl fluoridesby reaction with this reagentin CH.CN (35-92Voyield). Bromofluorinationof alkenescan be effectedwith AgF/CaF, and 1,3-dibromo-5,5-dimethylhydantoin (DBH). IodoDBH, AgFrcaF,

- ll

I

Cnr!CH:Cr{,

t t ' I

#=f

i-OH

C.H,CHCH,BT F

l{ fluorinationof alkenesis possiblewith AgF/CaF, in combinationwith I, or NIS (-60% yield).

OH L \ . - ,

;

-

|

l_-/

-si(cH3)3

C,,Hi ,

68% KNts(cH3)'l' J

CH.

il-

c,,H/C\r 3 rr.:rr. suchas 1. Reactionof the paffordsa fluoroalkene' c::.'.,.iisilazide yg.1,,ndingB-fluoroalcoholwith re.:-,'ut i )'/o Yl€lO.

r'::c.i cpoxideswith nitrilesand SiF. to SiF.are converted ur:hrr exposure carbon.In tr.:-hcdto the substituted il !r()mreactionsconductedat 80'.

-l

,rrl#\ I

C.H'' t " "

I T. Ando,D. G. Cork,M. Fujita,T. Kimura,andT. Tatsuno. (1988\. Chem.Leuers,lST1. Simmons-Smithreagent. Diastereoselectivecyclopropanation.t The optically activederivative 1 of cyclohexanoneobtainedwith (R,R)-2,4-pentanediol (n, 375-378)undergoesdiastereoselective cyclopropanation with the reagentobtainedfrom ZnlCu and CH'I, or (C,H,),Zn and CH'I,, but the highestoptical yield (95Vode) is obtainedwith the latter reagentin DME. The chiral auxiliary can be removedto provide the bicyclicalcohol3. The cyclopropanering of 2 is cleavedon oxymercuration(98vo vield).

."....J

cH3...r1,cH3 o o H I

A t

I

l

r.r,

o o H (CrHl|rZn, Cll"l., DME,2OP ---.--------.--. 56%

2 (95%de) I r1rcc ror*l 2)rqco, J

C'H',tN '

| )-"", O

k.. :e. 1101(1988);idem,ibid',30,967

3 I T. Sugimura,T. Futagawa,and A. Tai, Tetrahedron Letters,29,5775(1988).

Sodium anthracenide

Sodium-Ethanol. Alkyl fluorides.r ct-Fluorosulfides,availableby reactionof mercury(Il) fluoride with thioacetals,are convertibleinto alkyl fluoridesby reductivedesulfurization with sodiumin ethanol.

tj>."."o

rn,.il,o",a."r;a"an,o 48qo

Sodium(potassium)amide. Haller-Bauef cleavageof u'silyl ketones. Paquette'sgroup2has shownthat reactionof Na(K)NH, with optically active ct-silylphenyl ketonessuch as I in refluxingbenzeneprovidesthe correspondingsilanes(2) with 88-927oretention control is observedin the cleavageof of configuration.The samestereochemical as 3. such chiral c-silyl benzoylcycloalkanes

c6H5c-_ cH2cH2c6H5 HL (cH3)3si/"'cH3

o ll

c6H5cv^/'cH3

(cH3)3si1JDH 3

--------)

Sodium azide-Dimethytror Selective cleavagc of RO. alcohol by NaN, in DMF ar , phenylsilylethers.

I S.J. Monger,D. M. Parn..and

Sodium benzeneselenohtc.r..t Cleavageof oxetana.t O 1-phenylselenenylpropanol ar lanes)are cleavedonly ar () attackedby the reagent.Clcarr

Hv,cH2cH2c6H5 (cH3)3si7"'cH3 2 (87Vaee)

| (897o ee)

' C. R. Johnson andO. [:r.cr!c r C. R. Johnson, Aldrichim.Aclr

cHi

'S. T. Purrington (1988). Leuers,29,685l Tetahedron andJ. H. Pittman,

o tl

o tl c4scl{' -

H>/

d_*

'x'cH3

rcH.)"Si1_,r/\H 4 (98:2)

$.no

rReview:E. M. KaiserandC. D. Warner, (1975). Synthesis,395 ' J. P.Gilday,J. C. Gallucci, L. A. Paquette' J. Org.,54,1399(1989); andL. A. Paquette, C. S. Ra,andM. Hoppe,ibid.,54,1408(1989). G. D. Maynard, Sodium anthracenide(1). The reagentis obtainedby sonicationof sodium and anthracenein DME. Sulfoximines, R';{OX'.' Review.2 The mostattractiveroute to theseimines NH is reaction of a sulfoxidewith tosyl azide in the presenceof CuXt or with Ointermediate. (MSH) to givean N-tosylsulfoximine (mesitylsulfonyl)hydroxylamine Cleavageof the tosyl group is then effectedwith a sodium arenide,in particular with sodiumanthracenide.

I K. Haraguchi, H. Tanaka.H. Hr

Sodiumbenzyloxide,C.H.CH:C benzylalcoholand NaH in Ttil Conjugate addition to io zyloxideundergoes4r?!i-seled

Sodium benzyloxide

o l

o l

o

l

l

l$t cn,frc", cH3ScH3 #

t r rr.rctionof mercury(Il) fluorrJc. bv reductivedesulfurization

l

l cH,frcH, NH

NTS

:l' l

....r.o" '

';]>"".'*

)--;-," r

(1988)' le. 61151

group2hasshownthat P.:.luctte's rlr rhenyl ketonessuchas I' in , d : r . ( 2 ) w i t h 8 8 - 9 2 7 or e t e n t i o n r.. :. rrbservedin the cleavageof

I C. R. Johnsonand O. Lavergne, J. Org.,54, 986(1989). r C. R. Johnson,Aldrichim.Acta,18,3 (1985).

Sodium azide-Dimethylformainide. Selectivecleavageof ROSi(CHrl(CuIIr)rJ These ethers are cleaved to the alcohol by NaN. in DMF at 40owithout effect on r-butyldimethyl-or t-butyldiphenylsilylethers. 'S. J. Monger, D. M. Parry,andS. M. Roberts, (1989). J.C.S.Chem.Comm.,381 Sodiumbenzeneselenolate, NaSeCuH,(1). Cleavageofoxetanes.t Oxetanesare cleavedby this salt to the corresponding at room temperature,whereastetrahydrofurans(oxo1-phenylselenenylpropanol lanes)are cleavedonly at 60-100". In each casethe less-substituted carbon is attackedby the reagent.cleavageof oxiraneswith thisreagentis not regioselective.

,. llxilfH2c6H5

r-o

2 (817o ee)

,:lt/.f' 1 (98:2)

:

.< le75). 5{. 1399(1989);L. A. Paquette. -, . r1989).

2E9

| | 4"",

"X"fn' f"'

-#

&%

HOCH(CH,)'SeC.H,

cH2oH

f]

-+T--'uoCH1cH,;,secuH,

\6^cH,oH cuHrse -_--+ 86qo

nr.i hv sonicationof sodiumand o . ' . r t l r a c t i vreo u t et o t h e s ei m i n e s

' K. Haraguchi, H. Tanaka,H. Hayakawa, andT. Miyasaka, Chem.Letters,g3l(1988).

thc presenceof CuX, or with G intermediate' n \ -rosvlsulfoximine in particular arenide, .odium .r th

Sodiumbenzyloxide,C.HTCHTONa (1). This alkoxidecanbe generatedin situfrom benzylalcoholand NaH in THF at 25". Conjugate addition to nitroalkenes; anti-p-amino alcohols.' Sodium benzyloxideundergoesanfi-selective conjugateadditionto 2-nitro-2-butenes to give2-

Sodium borohydride

(2). Theseproductsare convertedinto P-aminoalcohols benzyloxy-3-nitrobutanes (3) by catalytichydrogenationin acidicethanol. t

R

t

I){O,

NO, |

l)l.THF

,

ziHorq-re.,R:An, Not

5o-1Mo

*

R*nt

I

Sodium borohydride-Ceriur( Ilfl Reduction of diphenylphol thesesubstrateswith NaBH. aloa cohols,whereasLucheconditionsr

:

ocH2c6H5

ocHrc6H5

o tl

2 (85-94:15-6)

,_,*l[;ffi'".,

(C6HJ/-y pr-,

oA..*,,

;,

R\4n'

NaBH. NaBH.+ ese,

6" = 80-90:20-10) 3 (antilsyn ' A. Kamimura (1989). andN. Ono, Tetrahedron Letters,30,731 Sodiumbis(2-methoxyethoxy)aluminum hydride (SMEAH) (1). Reduction of 2,3-eporycinnamyl alcohol (2).1 This hydride can effect selective reductionof 2,3-epoxyalcoholsto 1,3-diols,probablyby initial attackof the free hydroxyl group followed by intramoleculardeliveryof the hydride. The regioselectivityis decreasedby useof excessreductantor increasedby the presence of a free alcohol(methanol).

...4 crH}hoH )

o tl

(c5H5)2P- cH3 _ I l -

o4^w,.

{

NaBHo + CcCl.

Selective reduction of lrlolrl,. sodiumborohydride reduceso-fnx to a mixture of o-mannitotand >g

OH

t'o"u , excessI,

c,nlion 3 (22:l) 4-9:l

lY. GaoandK. B. Sharpless, (1988). J. Org.,53,4081

Sodium borohydride. Chemoselectivereductions. The reactivity of NaBH,,can be decreasedby use of a lower temperatureor by a mixedsolventsuchas methanolor ethanolicmethylene chloride. This simple strategycan be used to effect selectivereductionof ketonesin the presenceof enones,'and of aldehydesin the presenceof ketones.: 'D. E. Ward,C. K. Rhee,andW M. Zoghaib, (1988). Tetrahedron Letters,29,517 ' D. E. WardandC. K. Rhee,Syn.Comm.,18, 1927(1988).

J. Elliotf, D. Hall, and S. Warren. Ia R. Roy, S. Gervais,A. Gamiean.aod

Sodiumborohydride-Cerium(Ill)chloride

into p-aminoalcohols r .,)nr'€rted

NO"

)

'P' * "

R-lR'

I

l ocHrc6H5 c.H. | .: 9'1: 15-6) I u, parc, s: - *fc,npu, Hct

Sodium borohydride-Cerium(Ill) chloride. Reduction of diphenylphosphinoyl ketones qnd enones.t 1,2-Reduction of thesesubstrateswith NaBHo alone normally reducesthesesubstratesto threo alcohols,whereasLucheconditions(NaBHoand CeCl,)canresultin erythroalcohols.

o l

l . oAc.H,

-:l (1989).

le :\IEAH) (1). This hYdridecan effectselecl: rl. :.robablyby initial attackof the a: .icliveryof the hydride'The reiu;:.,ntor increasedby the presence

-

-

Ho

-

o (C6H5)f

cuH,

l

o tl (c6H5)2P

tl

(c6H5)rPY'CH3

I oU\pr

---4 Tteo

Pr-t

threo -5 :95 95:5

907o

o

y

+ l Ho"'\c.H,

erythro NaBH4 NaBHo + CeCl,

I

)

o l(C,HJrPy,Pr-, l

l

(C6H5)rP-yPr-i

\TI, I R-'Ant OH rr = 80-90:20-10)

291

Y | go*pr

CH3 + threo-isomer

50:50

NaBHo + CeCl,

Selectivereduction of ketoses, In the presenceof a large excessof CeClr, selectively sodiumborohydridereducesD-fructose(1) in the presenceof D-glucose to a mixture of D-mannitoland o-glucitol(2).'

OH a

c.n:^*oH 3 (22:l) 1-9:1

^.

bYuse t\ ,,r \aBHi canbe decreased :u!h as methanolor ethanolicmethu.(J to effectselectivereductionof of ketones'2 dcnrdesin the presence tt :,..,:t'tlron Letters, 29, 517 (1988)' c-- ie88).

f

Nox., ccct,

2

J. Elliotf, D. Hall, and S. Warren, TetahedronLetters,30,60l (1989). R. Roy, S. Gervais,A. Gamiean,and J. Boratynski,CarbohydrateRes.,l77, C5 (1988).

2n

SodiumdichloroisocYsnunte

Sodium borohydride-tifluoromethanesulfonic acid, NaBHr-HOTf (1)' Ring expansion. Alicyclic groups attachedto a hydroxymethyl (-CHTOH) or in an ethecarboxylgroupundergoring homologationon exposureto NaOSOTCF, -78" ion't carbenium to 25' via an intermediate real solventat CH.OH

#(,

r J . Z a k r z e w sS k iy, n .C o m m . . l t . : l - 1(51

Sodium O,O-diethyl phosphorotclr Debromination.r The reagentc 74-89Voyield.

(

n; ..C.tL(qlqo{ I H..hH r.l

The samereagentconvertsunsaturatedpolycycliccompoundsto diamondoid cagehydrocarbons.2 I G. A. Olah,A. Wu,andO. Farooq,l.Org.,54'1452(1989). ' G. A. Olah,A. Wu,andO. Farooq, ibid.'54,1450(1989)' andG. K. S.Prakash, Sodium borohydride-Zirconium(IV) chloride. r The combinationof NaBHoand ZrClo Reductionof C:O , Q:ltt , anl (-:N. (4:1) reducesketones,oximes,and nitrilesin THF at25'in85-96Vo yields'ReReductionof oximes duction of c:N and GN is slower than that of Fo. as reductant). BrHu with (obtained hydroxylamines than rather amines affords rS. Itsuno,Y. Sakurai, (1988). andK. Ito, Synthesis,995 Sodiumbromite, NaBrOr, 12, M5. Oxidation of ROH.I This oxidant can be usedto oxidize alcoholsin CH2CI2 when it is supportedon alumina;yields are generally>90Vo.It is also usefulfor oxidationof sulfidesto sulfoxides. rT. Morimoto,M. Hirano,Y. Aikawa,andX. Zhang,J.C.S.Perkin1,2423(1988)'

? ctttAN-t.la. --l Sodiumdichloroisocyanurate' |

(1).

oANAo CI Supplier:Aldrich. Chloramines.l This reagentchlorinatesprimary and secondaryamines,but is most usefulfor chlorinationof hinderedamines.The reactionis carried out in water or benzene-water.The co-product,cyanuricacid, is removedby filtration.

o

o tl CH"-I

,\

-i-.#{..I!X,

I-CH.

cHIN H

crr,

CI

coH,

Br

The debrominationcan also bc el

o tl

(CrHrO)rPNa, and a catalyticamounr X. HuangandY. Q. Hou,Syn.Comn .

Sodiumhydrogen selenide. Dealkylation of esterc.t NaHSc. DMF, is effective for cleavageof este {75), but this reagentis more difrcult

F. Kong,J. Chen,andX. Zhou.Srn. Ca

Sodiumhypochlorite,NaOCl. Oxidative decarboxylation.t Sod decarboxylationof o-hydroxy carbon hydroxylgroup is not essentialsinceu thisoxidation.Thustriphenylacetic aor andbenzophenone. In the presence ofe

(C6H')3CCOOH

"ttt,C,

and the ketone becomesthe major prc oxidation of 2,2-diphenylpropanoicaor acetophenone in the approximate ratrc

P.R. Elmore,R. T. Reed,T. Terkle-Hrx t O r 9 . , 5 4 , 9 7(01 9 8 9 ) .

SodiumhYPochlorite

(1)' d. \aBH.-HOTf (-CH' oH) or l, n'aro*rttthyl in an etheJtlr. ,o NaOSO2CF' ,,=*n1g6 ion'r

a^) i

rJ. Zakrzewski, Syn'Comm''lE' 2135(1988)' E' 455;10,362. Sodium O,O'diethyl phosphorotelluroate' into alkenes uic-dibromoalkanes converts reagent Debromination't The 74-89VoYield.

l

Br

-\

('

q\9 ).

l,^.'tt'

'iUia' ' Sq'1450(1989)'

of NaBHoandZrCL c ;.,nrhination Re.tli'.'t ,t ,:i' \n 85-964oYields' oximes of ., C:O. Reduction reductant)' as B2Ho La'r..twith 9\\

alcoholsin CHzCI: : u-cJ to oxidize It is also usefulfor .".titt t**' l' 2423(1988)' 11; ,/ ('.S.Perkin

I

H')-tg '8,

comPoundsto diamondoid

t;.ri

,l)

c^H.

cuH,

!-

H

cuHr. " "\:1

. : - l - - ' 1--*"6,np;itena-

+Te

ctHt

H

Thedebrominationcanalsobeeffectedwithsodiumo,o-diethylphosphite'

o il

and a catalyticamountof tellurium' (CrHrO)rFNa, (1988) rX. HuangandY. Q. Hou,Syn.Comm',18,2201

SodiumhYdrogenselenide' in generatedin situ from Se and NaBHo Dealkylation of esterc'r NaHSe' (11' reaction this CuH'SeNaalso effects DMF, is effectivefo. .f"unugt of esters] and handle' prepare to difficult +ZS;,'Uu,this reagentis more lF. Kong,J. Chen,andX' Zhou' Syn'Comm''18'801(1988)'

Sodium hYPochlorite,NaOCI' hypochloriteis knownto effectoxidative Oxidativedeco'boryiotio''L Sodium a acidsto form ketonesand CO" but decarboxylationof o-hyJroxy carboxylic hydroxylgroupisnotessentialsincetrisubstitutedaceticacidsarealsosubjectto is oxidizedby Naocl to triphenylmethanol thisoxidation.Thustriplenylaceticacid andbenzophenone.Inthepresenceofaphase-transfercatalyst,therateisenhanced

I

Naocr + (c'Ht)'c:o + cot ' (cuH5)3coH (c6HJ3ccooH "Ti",":: :l:tn | .nmarv andsecondarl out carried is reaction ,r.,";.. The by filtration' ,"""tt. acid,is removed

o >.rr

a\ I

l-CH,

.,,)ooActt' CI

(13-201o)

(24-421o)

product (g\-g4vo yield). A similar, catalyzed and the ketone becomesthe major and providesa mixture of benzophenone oxidationof 2,2-diphenrfpl"p-Lit acid ratio of l:2:5' in the approximate acetophenone J' S Welch'S' M' Young'andR' G' Landolt' P.R. Elmore,R. T. Reed,T Terkle-Huslig' (1989)' J. Org.,54,970

294

Sodium phenylseleno(triethoxy)borate

Sodium molybdate(Vl)-Hydrogen peroxide' Na2MoOo-HrO'. Singlet orygen.t This combinationresults in sodium peroxomolybdenate, NarMoO6.This reagentcan be generatedon a macroreticularresin suchas Am10. berlystand usedas a chemicalsourceof singletoxygen,

Sodiumtetraborate(borax), Na:B.O-:rl.. Hydration of cyanohydrins.' Thc undergohydrationwhentreatedwith bora in 65-85Voyield. In somecasesadditiono

RCHC\#

ffYo"--*ffi

OH

65%

\,.\2

ooH ooH

I J. Jammot, R. Pascal, andA. Commerras li

I

(CHr),C:C(CHJ, J;+

(cH3)rc-ccH, tl

CTL : E. C. McGoranand M. Wyborney,Tetrahedron Letters,30,783(1989)'

Sodiuft periodate. Gtycol cleavagelquinones.t Glycol cleavageand oxidationof hydroquinones to quinonescan be convenientlycarried out in CHrClt with sodium periodate supportedon wet silicagel. Water is essentialand the amountis the most critical factor. The procedureovercomesthe problemof insolubilityof NaIOoin organic solventsand shortensthe reactiontimes to generallylessthan 15 minutes.

Sodium tetracarbonylhydridofernte. \a' I ArNO, --+ ArNHz.t Na-[HFe(COl.l medium.However, the bis(triphenr.lptro in combinationwith a strongBronstedrc ticularlyfor nitroarenes,even in the prcse

C.HrNOr+ppN'[l{F(CO

' P.L. Gaus,S. W. Gerritz,andP.M. Jefincs : M. Y. Darensbourg, D. J. Darensbourg. an ( 1978).

64 (1989)' I M. Daumas, andF LeGaffe,Synthesis' L' Vo-Quang, Y. Vo-Quang, (l')' L4' 284' Na*[C6H,SeB(OCzH'):]Sodiumphenylseleno(triethoxy)borate, substratesto pthese Reiuction of o,rp_epoxyesters.t The reagent reduces

Sodiumtungstale,NazWOr. Oxidation of sec-aminesto nitroet. drogenperoxideoxidizessecondaryaminc

hvdroxyestersin 80-907oYield.

A

cH3(cHr)3N(cH)3cH3 H r

I

lqor orrol rir'\ro' e

r

/ \ cooc2Hr C2H5OOC c$ or tro'ns

f

o

H

l

| .,",oo"\cooc2H5 l t=;-

L

o H c,Hsooclcooc'r!

lecuH,J

r M. Miyashita,M. Hoshino,T. suzuki, and A. Yoshikoshi,chem. Letters,507(1988)'

H. Mitsui, S. Zenki, T. Shiota,and S.-1.Ill Org. Syn.,submitted(1988).

Sodium tungstate

). ll o.. i(\.llum peroxomolybdenate, orrircularresinsuchas Am?n.().

Z9S

Sodiumtetraborate(borax),Na,BoOT; 4, 46I. Hydration of cyanohydrins.t The cyanohydrinsderived from aldehydes undergohydrationwhentreatedwith boraxin waterat g0.to giveo-hydroxyamides in 65-85voyield. In somecasesadditionof a traceof KCN can increasethe yield. NA,BAq' 80'}

RCHCN |

65-85qo

OH

RCHCONH. I

OH

rJ. Jammot,R. Pascal, andA. commeyras, Tetrahedron Letters,30, 563(19g9).

OH -ccH3 I

ct{. 1

-..i (1989).

I ,.udationof hydroquinones I ( I u'ith sodium periodate is the most critical e .1m()unt o o i u \ r l i t v f N a I O oi n o r g a n i c lc.. than 15 minutes. . r . , : t l e s r6s 4, ( 1 9 8 9 ) . f r t ) ( . H . ) . 1 ( l ) , L 4 ,2 8 4 . rluccr thesesubstratesto P-

Sodiumtetracarbonylhydridoferrate, Na- [HFe(CO).]- (l). ArNo2-"> ArNHz.t Na.[HFe(co)o]- is a known reducingagent in a basic medium.However,the bis(triphenylphosphine)imine (ppN-) saltof HFe(co)a-r in combinationwith a strongBronstedacid (TFA) is also a reducingagent,particularlyfor nitroarenes,even in the presenceof aldehydesor acid halides. Ja'' 5i CuHrNO, + PpN-[HFe(COynl-

C6H5NH2

'P. L. Gaus,S. W. Gerritz,and P. M. Jefries,Tetrahedron Letters,29,50g3 (l9gg). : M. Y. Darensbourg, D. J. Darensbourg, andH. L. C. Barros,Inorg.Chem.,17(Zg7) ( 1978). Sodiumtungstate,NarWOo. oxidation of sec-aminesto nitrones. In the presenceof this tungstate, hydrogenperoxideoxidizessecondaryaminesto nitrones.r &q, cH,oH

CH3(CHr)3N(CHJ,CH, #* H

OH I

. c'.H.ooc&cooc'Hr

. (,:crrr.Leuers,507(1988)

6rw

CH,(CH'),Ii:CH(CH,),CH3 -"1

o- . + | l 7a-114

N H

cH,

-T^an, |

|

o-

H. Mitsui, S. Zenki, T. Shiota,and S.-L Murahashi,J.C.S. Chem C o m m . , 8 7 4( 1 9 8 4 ) ; Org. Syn., submitted(1988).

296

Squaric acid

(f )' Sorbic acid (2,4-Hexadienoicacid), CH:CH:CHCH:CHCOOH dianion (2) of The acids.t Pentadienyl hydrory acids;7-hydroxy-2,4-dienoic acids (3) hydroxy pentadienyl 1 reactswith carbonyl compoundsto afford either Reaction conditions. the reaction acids(4), dependingon or 7-hydroxy-2,4-dienoic

N-Sutfinyl-p-toluenesulfonamide.Ts\:S I ntramolecular cycl ization of ll -tosvl rated aldehydesinto N-tosyliminiumcoo to homoallylicamines. cyclization

COOH

"+*

1uN(c'H'\' l,r^,-'-;"1 ,

"I*."

nJ..1^[ \G/

t

ur* | t.,",I.-o, ro"

+

'i";fiz-'z-*o 4

o '*

"r)'-=/"-""t,

l- ? f,", ^^^.:l gl.n/#f-cooHl CH:cH, J

L

ry t

H' l clt,

' M. J. Melnick,A. J. Freyer,and S. M. l'lcro

t

l'" q

9.H5

*r|/--(\AcH, COOH 6 which graduallyrearof 2 with a substitutedenoneaffordsinitially a 1,4-1-adduct, (6). rangesto a 1,4-ct-adduct J'C'S'PerkinI'2797(1988)' rP. Ballester, andR' Mestres' A. Costa'A. Garcia-Raso' Squaricacid. 1,4-Benzoquinones(13,284).Fulldetailsoftheuseofadialkylsquaratefor are now available'The route to highly substitutedbenzoquinones a regioselective comparableto allerginicity report includesa note of caution:Theseestersshow that of the activeprincipalof poisonivy'' S' L' Xu' S' Patil'andH' W' Moore' I L. D. Foland,J. O. Karlsson' S' T' Perri,R' Schwabe' (1989). 975 111, Am. ioc..

Sulfur. O-Carbonylationof alcohols.t Rer presence of a tertiaryamine(DBU) in Tl with CoHrCH2Br afiords9b esterification

o

DBU'80%) tl RocS . ( D RoH + co + s I

can hardly involve carbonylsulfide.rrhrc at high temperatures(>250"). The lreld beingabout 5Vowith Bu.N and zero rith

T. Hirashima. A. Og T. Mizuno,I. Nishiguchi, 29,4767(1988). Letters,

ts( I'lcooH (1).

k acids.t The dianion(2) of rntudienYlhYdroxYacids(3) rc.ictionconditions.Reaction

o

COOH I H\,)-',-4/-..-/cH,

,

-

TsN:S-O (1). N-Sulfinyl-p-toluenesulfonamide, Intramolecular cycliZation of N-tosylimines.r The reagent convertsunsaturated aldehydesinto N-tosyliminiumcomplexes,which undergo intramolecular to homoallylicamines. cyclization

c-tl/-ou 3

rsrir-sr;-l ' " t L- - ' l | "c),,]'J,ton,r,"\ l-

|]

11

IA

\-f.t-/

|

l\r|--lCH,

CH.

L

I

J

t r"l NHTs H :

NHTs H'l'^

x'""1 \,,,,\CH, Dl{

?-V\ t - t t * t l l CH,

r'rVtV CH, -

(1988). rM. J. Melnick,A. J. Freyer,and S. M. Weinreb,Tetrahedron LeUers,29,3891

Sulfur. of an alcoholwith CO andS in the of alcohols.t Reaction O-Carbonylation presence of a tertiaryamine(DBU) in THF at 80' resultsin a product(1) thaton (2)' The reaction carbonothioates affordsS-benzyl with CoH.CHrBr esterification

o

o tl

il

c'H'cH'Br DBU' 8o7o r RocscH,c^H. , ROCS-(DBU.H). RoH + co + S 12-85qo 1-.rJduct,which graduallYrears .r ( S. Perkin1,2797(1988)'

lhc ure of a dialkYlsquaratefor are now available'The Lurnr)nes Dos allerginicitYcomParableto i i \u. S.Patil'andH' W' Moorc'

I

)

can hardly involve carbonylsulfide,which can be made from CO and S but only at high temperatures(>250'). The yield of 2 is highly dependenton the amine, beingabout 5% with Bu,N and zero with pyridine. Tetrahedron N. Kambe,andN. Sonoda, A. Ogawa, T. Hirashima, T. Mizuno,I. Nishiguchi, T), 4767(1988). Letters,

f(fi

molecularsieveand yieldsare loser. SE presence of a MOM etherby this merlx

I T. Kan, M. Hashimoto, M. Yanagira. and ( I 988).

Tellurium. Tellurobenzaldehyde. This aldehyde (a) is formed in situ by reaction of Te to form the Dielswith (cuHr)rP:CHCuHsandtrappedwith 2,3-dimethylbutadiene reagentto form Wittig the with Alder adduct1. In the absenceof a diene,a reacts stilbene (61.Voyield).

f"'f"'

c.HpH,

(CrHr)rP:CHCuHr+Te

ro5' )

[re:cHCuH,t#

cH,:lt"

"r$.,",

Tetrabutylammonium(tricarbonyhitoo crystals,m.p. 56". The salt is prepare NaNO, and with BurNBr in H,O ar li'. Alkylation of allylic carbonotes.t I the alkylationof allyliccarbonates\r'itht reactionoccursselectivelyat the carbo retentionof configurationof the doublc of configuration,possiblyby two consd

1 CH"' rG. EikerandR. Hock,Angew.Chem.Int. Ed''28' 179(1989)'

l. co. THF

|

cH,:cHC-oco.c.H. ' l l

t

N€H(CGJ'A p a

I

(1)' Telluroniumylides,Bu,Te= CHY (Y = COOCH.' COC6H.'or CN) preparation (.f., 12, 159-160). cyanomethyldibutyltelluroniumchloride bromide(Y: COC6H5)are preparedby (Y = CN) and phenacyldibutyltelluronium respectively'followed by CuHrCOCHrBr, and CICHzCN with reactionof BurTe KOC(CHr)r. with reactionof the salts give wittig reactions.t Theseylidesundergowittig reactionwith aldehydesto reactions, two latter of the case the In nitriles. or ketones, a,p-unsaturatedesters, the ElZratio is I2-I24:1. It is more convenientto carry out this reactiondirectly or with BurTe and the aromatic aldehydeplus XCH,COOCH3, XCH'COC.H" the than 907o) (usually about yields gives higher reaction xcHrcN. This one-pot two-stepreactionthrough the telluroniumsalts' THF,

+ BurTeandXCrIY ;i RC5HICHo

nC.u.CH:CHY

(1988)' rX. Huang,L. Xie, andH. Wu,t' Org.,53,4862 Tetrabutylammoniumfluoride-Hexamethylphosphorictriamide, Bu4NF-HMPT. Clea:vageof SEM etherc.t (Trimethylsilyl)ethoxymethyl (SEM) ethers are I' hour cleavedby BuaNFin combination with HMPT and 4-A molecular sievesin of the absence in the hours 15 requires reaction yield. The at 100oin 90-98Vo 4n

CH,

9H'

I CHt:QtlQ-O{ I

cH.

oco2cH3 CuHs,r.-

CH, _ I ocorcH3 .-t, NaCH(COOCH,\ 78%

('13Voee\

,,\.,.2

r7l

Y. Xu and B. Zhou, J. Org.,52,974(l98a

Tetrabutvhmmonium (tricarbonvlnitrosvl)ferrate

molecularsieveand yieldsare lower. SEM etherscan be cleavedselectivelyin the presenceof a MOM ether by this method. I T . K a n , M . H a s h i m o t o , M . Y a n a g i y a , a n d H . S h i r a h a m a , T e t r a h e d r o nL e t t e r s , 2 9 , 5 4 1 7

( I e88).

is i.rrmed in situ by reactionof Te rneth\lbutadieneto form the Diels1;'. rrith the Wittig reagentto form

_j_c&r x_,it'!n'^.. ::t

cH,-.,-t ll i_ cH-crH5

-e (

I

BuoN[Fe(CO.)NO](1), yellow Tetrabutylammonium(tricarbonylnitrosyl)ferrate, crystals,m.p. 56". The salt is preparedby reactionof Fe(CO).in benzenewith NaNO, and with Bu,,NBrin H,O at 25'. Alkylation of allylic carbonates.t In an atmosphereof CO, this saltcatalyzes the alkylationof allyliccarbonateswith the sodiumanion of diethylmalonate.The reactionoccursselectivelyat the carbon substitutedby the leaving group with retentionof configurationof the doublebond. The reactioninvolvesnet retention of configuration,possiblyby two consecutiveSx2reactions.

CH" 1989).

CH,

:lt COC.H.,or CN) (1). n:crhrldibutyltelluronium chloride bY are PrePared nrJc tY: COCoHs) by followed respectively, ll.Br, 0(

QH, + (cH,)rc:cHcHr(coocrH5), CHr: g11a-cH(CoocrH5), 92:8 cH.

l.rt:rgreactionwith aldehydesto give rhc .'rie of the lattertwo reactions. ir'ti'rr,coffYout this reactiondirectly \( tt.coocH3, xcHrcoc6H5, of rrc.J: (usuallyabout 907o)than the L\

'

i+

l

-

75%

oco2cH3 cuHs

THF

'!\\

r RC^H,CH:CHY

I, CO, THF

t "

NacH(COOC.H.L ------------:--: CH,:CHC-OCO,C,H. '18% l

-r."

, I

cH(coocrH5),

CH,

6corcH,

I' NacH(coocH'L t

(731oee) l

CuHs _r.-

*

I

CuHt',r1..CH,

CH,

'

*

eH(coocu.)2 locphoric triamide, Bu4NF-HMPT. [\.rcthoxymethyl(SEM) ethersare I ,n,l -l-A molecularsievesin t hour !rc. 15 hours in the absenceof the

(73% ee)

9j:7

I Y. Xu and B. Zhou, l. Org.,52,974(1987);ibid.,53,4419(1988).

l

cH(coocq), ('t39oee)

300

Tetrakis(triphenylphosphine)palladiun(0)

TetrachlorophthalicanhYdride. This conversioncan be effectedinT0-90voyield RtcooH.l RrcoNHRr ---> water or of a by tetrachloro-or tetrafluorophthalicanhydridein the absenceof Conversionof solventin a melt at 135-170".This reactiondoesnot affectesters' with tetrafluoronitriles to carboxylicacidscan be effectedby a similar reaction yield. 60-85Vo in days 4-6 135-180'for at acid or tetrachlorophthalic Letters' andG. w. Gribble,Tetruhedfon rJ. T. Eaton,W. D. Rounds,J. H. Urbanowicz, (1988). 29,6s53,65s7

(TCA). 2,6,9,l0-Tetracyanoanthracene Diels-Alder reactions,t Diels-Alder reactionsbetweenelecPhotosensitiZed But in tron-rich dienesand electron-richdienophilesare generallyunproductive' reain occur can cycloaddition this the presenceof TCA or dicyanonaphthalene ,onubl"yield.Thusl,3-cyclohexadieneundergoes[4+2]cycloadditionwithpclol2.2.2foct-2-enewith retenmethylstyreneto form endo -6-methyl-5-phenylbicy tion of the styreneconfiguration'

a\\^,Jffin, /ht"'

C.H,CH:CHCH'* V

P1

MoMo

o\-.,'4,

(c,H,),NfifttlYV o *2&

Cyclizative Heck coupling. Thrs rc of c,B-unsaturatedcarbonylcompound

a>a\acoocHj |

i

\,A,

l

i

l

.

/ coocH3

*;s

-

-

I

n

.-\-->-

. ll)---l-ctt, + 12+2l I

cis CuH,

trans CuH, SlVo lVo

trans cis

Example:

617o

57o l07o

I D. Hartsoughand G B. Schuster, l. Org.,54' 3 (1989).

Tetrakis(triphenylphosphine)palladium(0)' I on deprotonatton Intramileculir arytation. Aromatic substratessuch as (NaH)furnishstabilizedenolatesthatundergointramoleculararylationwhenheated

z, z'

f'^fl \o,''ry(l\^rn^ 4a-6s% \,ry

VariousalkenylethersundergoHec\ of a Pd(0) catalystto form cyclic ethen zopyrans.l

."r-rfg

,-".*A, lCH,

\Z!.(cH)"

1@,2'=CN, COOR,C0R)'n=l'2

n,?,*

2

atl40"inthepresenceofaPd(0)catalysttogivebenzo-fused,five.orsix-membered CH''' rines.Yields are poor when Z (or Z') is H or

Aao-^

<,lJ-,V;

Tetrakis(triphenylphosphine)palladium(0)

Example: ?r.: :r can be effectedrn70-907a Yield d:r.:. ln the absenceof water or of a n .r'r. flot affectesters.Conversionof L,: ., .rmilar reactionwith tetrafluoro.! ^ .l.rvsin 60-857oYield.

NrH,Pd(0) D M FI 3 5 ' '

(c,H.),NC --'tl

ll (C"H.),Ni

76%

o H,C

CH,

Letters, r .,^.:(i. W. Gribble,Tetrahedron CyclizativeHeck coupling. This reactionis highly regioselective in the case of ct.B-unsaturated carbonvlcompounds suchas I and 3.r

pd(olN(qHr, _coocH3--G
I

I )reIs-Alder reactionsbetweenelecil(. .rregenerallyunproductive.But in can occurin rearrc ihrscycloaddition txlrig,res[4 + 2lcycloadditionwith pwith reten.2.2loct-2-ene r: r :brcvclo[2

' '^)

\.L,

\-,qcH,coocH3

/' coocH3 I

9H' 3

.:

,,o ro,o, J

cis CuH,

r'-,.., CuHs . .i

6l7o

5Vo l07o

aT')

V/-------\cHcoocHr

.rs9)

4

.L-.tftrtes such as I on deprotonatron rr, rrtramolecular arylation when heated Z z '

\,"

tst

CHr.-,A^ lt i

lt'

:"',1

VariousalkenylethersundergoHeckcouplingin a basicmediumin the presence of a Pd(O)catalystto form cyclic etherssuchas benzofuransand tetrahydrobenzoDvrans.r

ll icul"

\/ l

|

.^.-. ,?-nex t 2 ll CHt

,

zo:21

, :ir l benzo-fused,five- or six-membered J - l, , r ( ' H , . '

N(crH,)r,PdlP(c6Hr)rl. CH.CN,THF,A

e1q'

4",_io i l l n-Hex/\( CH,

, H z^ - o--1.,\

<4, U#UH-/

102

Tetrakis(triphenylphosphine)palladium(0)

13 + 2lAnnelation. The Pd(O)complexin combinationwith N(CrH'), (1.52 equiv.) effectscyclic carbopalladationof substratessuch as L, a cyclohexene substitutedby a 1-iodoallylelectrophilegroup and activatedby a carbonylgroup,

g C.HTCH:CHCHTOH+ C.HTNCO

coocH3

coocH"

Allylidenation of aldehydes.' Thrs g trialkylphosphinepromotesa reactionbe coholsto provide1,3-dienes.

#lt,i.ti,^k1 ^+^. \) ,Aru-';-V- H {u, coocH3

coocH"

*"o#1,;,ii'., 61s' -f^n

aln1\ \=2 /'2

This Wittig-like reactionprovidesa ror

cHroH

o to undergo[3 + 2]annelationto a [6,5]bicyclicproduct (2). The secondexample is an exampleof carbonylative[3 + 2 + 1]annelation.a Pd-catalyZed intramolecular ene reactions.s Both this complex and Pd(dba)r,havebeenusedto effectthis intrabis(dibenzylideneacetone)palladium, molecularcyclizationof dienescapableof forming allylpalladiumcomplexes.

Y

pd(dba),

al-v

P(C.H.).,THF

T,a>/ il

|

(Y = COOCH3)

Ts

PdrP(c.H,)rr.,HoAc, A

-

/

Ts. -Ts

Ts

$q'

t/

t"o)

crL cH, Ts

Ts I /N\

t

I

l

fc4\cH, OAc

a*\ t l

+ 63%

cH,

3-Aza-Cope rearrangement.l This rs by Pd(0) and a strongprotic acid, parrior fonic acid. This isomerizationis involved iminesfrom allylamineswith carbonvlcq

o)C6HsNH ^...ft"'. "q{ Lcr

(Y

cH,

lcx,r
|

tl CH,

CH,

oHc

crL

I

Tetrakis(iriphenylphosphine)palladium(0)

r.mhinationwith N(CtH'). (1.5lraic'r SUChas 1, a cYclohexene d .rctrvatedbY a carbonYlgrouP'

303

Atlylidenation of aldehydes.6This palladiumcomplexin combinationwith a trialkylphosphinepromotesa reactionbetweenphenyl isocyanateand allylic alcoholsto provide 1,3-dienes. C.HTCH:CHCH2OH

+ CuHrNCo

PBul Pd(o)' t [CuHrCH:CH-CH:PBu:] sr-rsr, | *'cno I

'-Y^n coocH.

VY

C.HTCH:CH-CH:CHR2 E , E / E , Z= 1 * 4 : 1

This Wittie-like reactionprovidesa route to all-transp-carotene(1).

CH, CH.

9H,

9H,

, l )(r\.\-cH2oH [

o pr(,duct(2). The secondexamPle

*osc\AAacHo 1 " ,

\'^cH3

.,ol;g;n'o

!l,rlttln.'

I

i o n s . s B o t h t h i s c o m P l e xa n d rarc beenusedto effectthis intracomPlexes' Lnr.rllvlpalladium

CH,

CH,

CH,

9H,

3-Aza-Copereanangement.l This reactionproceedsreadilywhen catalyzed by Pd(O)and a strongprotic acid, particularlytrifluoroaceticacid or methanesulfonic acid. This isomerizationis involved in a direct synthesisof 8,e-unsaturated iminesfrom allylamineswith carbonylcompounds(equationI). The unsaturated

Ts

Ts

ll

Pd(o)

0) CH,

t

cH.y'$cH,

|

c6H5NH

cH" '

f

c.Hr

t " - H' cHo

Acn"

a.",rl-r4it,

I 82% P(o), 5oe I

Ts /N\

Acrr.

HrC-

l

arrO"r&;;,

2,2,6,GTelr amethyl-2,Gdisilapiperidine

imines can be reduced (NaBH) to unsaturatedamines, or hydrolyzedto unsaturatedcarbonylcompounds(equationII). This rearrangement showsrather low asymmetricinduction(one example).

Preparation:'

CH,:CHCH,Si(O

;ll'fl'* H.c^ 0t)HN(cHrcH:CHz)z+tT

kr^, OHC- 'C.H, 80% sfleral sEPs I

CH.

c"H.)--r - t

\

\nlan, ' M . A . C i u f o l i n iH , . - B . Q i , a n dM . E . B r o w n eJ, . O r g . , 5 3 , 4 1 4 9( 1 9 8 8 ) . 2 B. O'Connor,Y. Zhang, E. Negishi,F.-T. Luo, and J.-W. Cheng,Tetrahedron Letters,29. 39030988). 3 E. Negishi,T. Nguyen,B. O'Connor,J. M. Evans,and A. Silveira,Jr.,Heterocycles,?3, specialissue,55 (1989). 4 Y. Zhang,B. O'Connor,and E. Negishi,l. Org.,53, 5588(1988). 5 W. Oppolzer,PureAppl. Chem.,ffi,39(1988);idem,Angew.Chem.Int. Ed.,2E,38(1989). 6 N. Okukado, O. Uchikawa,and Y. Nakamura,Chem.Leuers,1449(1988). ? S. Murahashi,Y. Makabe,and K. Kunita,J. Org.,53,4489(1988).

Tetrabutylammonium fluoride, BuoNF. 2-Aza-1,3-dienes.t The reaction of imines (1) of aldehydes obtained from bis(trimethylsilyl)methylamine with aldehydes catalyzed by Bu.NF (Peterson alken ylation) provides 2-aza-1,,3- dienes in 65-7 8% y ield. R'- -H '.

RtHo,Bu.NF ) RICH:N_CH:CHR2

|

N\cHls(cHr)rl,

Primary amines.2 A ren the potassiumamide preparc the rangeof 60 to 90%.

I) KH, THF

I

2) cH,(crq),Br ) 89%

(cHr

' M. Ishikawa, M. Kumada. andI I A. Hosomi,S. Kohra.Y, Tomr 23420988).

Tetramethyl orthocarbontc. ( Thiiranes.t In the prcsc 2-mercaptoalkanols into rhitn + C(OCH CH3CHCHTSH -l OH

65-'t8%

2(Elz-r:r)

I

hardly involve a simple acid< essential;possiblythe actualn

T. TakataandT. Endo.Bull Ch ' J. Lasarte,C. Palomo,J. P.Picard,J. Dunogues, andJ. M. Aizpurua,,I. C.S.Chem.Comm.. 72 (1989\.

t"'\^.,rt"' /-s{

2,2,6,6-Tettamethyl-2,6-disilapiperidine, (

\_sirNH / \

CH,

CH,

(1).

(TIlt I, 1,3,3-Tetramethyluree Glucosidation.t Glucosr 3.4,6-tri-O-acetyl-B-o-gluco in TMU as solventand in rhe qf 110-120'with continuous conditions,cr-and p-glucosrd M. Nishizawa, Y. Kan.andH \

I,1,3,3-Tetramethylurea

lur'.::td amines,or hydrolyzedto unl f hr: rearrangement showsratherlow

n ",.1 l; =-

CH"

\

\oAcn, ; , ' . , . 5 3 . 1 1 4 (91 9 8 S ) . : - .: -\\ Cheng, TetrahedronLetters, 29.

I JL

I -..r ia\$ ( l9ti8). k\ , : t e v .C h e mI.n t . E d . , 2 S 3, 8( 1 9 g 9 ) . ( . " 1 . . ' t t e r s . 1 4(4i 998 8 ) . ^r 5.1 .rJ89( 1988).

d<.

I r of aldehydesobtained from ,.rlalvzedby Bu.,NF (peterson r ield.

R CH:N_CH:CHR2

(cH3),iicH,cH,cHz,Si(cH,y, cl

cl

Primaryamines.2A versionof the Gabrier synthesis invorves arkylationof thepotassium amidepreparedby reactionof I with KH. yields are genera,yin therangeof 60 to g\Vo. r) KH,rHF

,'--Si(CH)z \

2) cH,(ctLLBr ,/ . ---;; (cH,),

-

.:.j .{. Silveira,Jr.,Heterocycles,2t.

ln:

_#+ iHrCHrCHrSi(CHJ3 si(cHJ3

LcH^

I e0% severa scls J

r:.

clsi(cHJ,,

CH,:CHCESi(CH3)3 ;

-/\ oHC- .cuH,

c^H.)-\ 't

305

Preparation:'

Hcl-tlo

-#/N(cH2)?cH3 :-Si1CH;,

cH3(cH2)iNHz

lM. Ishikawa,

Kumada, andH. Sakurai, J. Organomet. Chem.,23,63 'i;iiir"#fii. SM.Kohra' (lg7tJ). Y'rominaga, M.inJ,,;; H.sakurai, pia',mBuu.,fi. cnem. Tetramethylorthocarbonate,C(OCH,)., b.p. 114".Supplier:Aldrich. Thiiranes.t In the presenceof an acid catalyst,TsoH, this reagentconverts 2-mercaptoalkanols into thiiranesin about 10 minutesat 25.. This reactioncan CH3CHCH2SH + C(OCH.). " ' l iS+ qo | OH

A /--s,+O:C(OCHr),+2CH,OH CHr/

2 ( E / Z- t : l \

n.i \l Aizpurua,./.C.S. Chem. Comm..

!ll, . -S:

\ lr .S: CH.

(r)

hardly.involve a simpleacid-catalyzed dehydrationbecausean orthocarbonate is essential; possiblythe actualreagentis (CH.O),C-. rT. Takataand T. Endo,BultChem.Soc. Japan,6l,lglg 09gS). 1,1,3,3-Tetramethylurea (TMU), l, 1 146. Glucosidation.t Glucosidescan be prepared in 50-g0% yield by reactionof ]'l!-jlio-".etyl-B-o-glucopyranosyl chroridewith a primaryor secondaryalcohol in TMU as sorventand in the pr.r.n.. of 4-A morecurarsievesat a temperature 9f 110-120'with continuousremovarof water from the reaction.Under these conditions,o- and B-glucosides are formed in about equal amounts. lM. Nishizawa, y. Kan,andH. yamada, Tenahedron Letters,29,4597 fi9gg).

306

Tetraphenylantimonyhifluoromethanesulfonate

Tetraphenylantimonyiodide, (C6H5)1SbI. y and 6-Lactones. In the presenceof this reagent,diphenylketene(or ethylphenylketene)undergoescycloadditionwith oxiranesand even oxetanesto give lactones.Benzeneis the solventof choicefor reactionswith oxiranes.t (c6lt').sbl

(C.H.).C:C:O C.H.CH-CH.+ " " \o/

2,3,4,6-Teta-O-pivaloyl- p-o-gdrcrogl PivO t

t{//

1

Ofi

\

c'& , et%

Piv\_--

c"H. " "l--

Pi

C". H-.X - | . - ,\o

CuH, 'lf o

(Rl-a-Amino acids.t This carbohy as well as the amine in the Ugi four-co amino acids(7, 366).,

CH":CH CHr:g11-al{-FH, vn2-vrr -(J

+ (CuHr)rC:C:O

iS --;5"a."r|

,rr,,O CuH, y o C.Hrr

PI l{c@f(

4, l+R'cHo+(CH,),CNC

Ph

,a-
o

tM. Fujiwara,M. Imada,A. Baba,and H. Matsuda,J. Org.,53,5974(1988).

(CoH,)4SbOTf (1). Preparation.l Tetraphenylantimony trifluoromethanesulfonate, p-Amino alcohols.2 In the presenceof this salt (1), amines(primary and secondary)reactwith oxiranesto give B-aminoalcohols.The reactionwith terminal resultingin B-cleavage almost exclusively.No oxiranesis highly chemoselective, or (CoH,)rSbCl rearrangement of oxiranesto allylicalcoholsis observed.(CoH,).'SbI is lessefficientthan the triflate, which has the added advantageof solubility in CH,CI,.

+HN(G,H,), #;G..,",,,

O"

' H. KunzandW. Pfrengle, Am. Soc..ll0. 6 :R. UrbanandI. Ugi,Angew.Chem.Int.E

Thiolaceticacid, CH.COSH. Chiral dithioacetals,t In the presea and thiolaceticacid reactto form a mirct be deacylated(KrCO3,NaOCH.. or CH (2). dithioacetals zlt

S R'CHO + HSR2+CH"COSH -

65-9t

ncofu

o

o.oTN(C,H5), + HN(C,H,), 8%

'R. Riither,F. Huber,and H. Preut,J. Organomet. Chem.,295,21(1985). 2 M. Fujiwara,M. Imada,A. Baba,and H. Matsuda,Tetrahedron (1989) Letters,30,739

.

Thiolacetic acid

(1). 21314r6-Tefia-O-pivaloyl-p-o-galactopyranosylamine r..:!cnl. diphenylketene(or ethylft:.:nc\ and even oxetanes to give e.r.i l()nswith oxiranes.' b. +

PivO

c^H. " "\---

t"H'{

C"HiY

b

(R)-a-Amino acids.t This carbohydratehasbeenusedas the chiral auxiliary as well as the amine in the Ugi four-componentcondensationfor synthesisof oamino acids(7,366).'

o

,-,

'H' ''Sbl

,:C

PivO

CH.:CH

PivO

,

COH'J

\

ryo C"H; X

OPiv

HCO

HCOOE

1 + R'CHO + (CHr)rCNC

*\

I

,

N__ CONHC(CH3)I

PivO

H"'\'

-,

^CuH' a ''l

> r ' . l l . rI

I

n-ev"! l) Hcl cH,oH

t'rt.ZVu tl

o

HrN

_ COOH H"'\'

r : . : . . j . r .l . O r g . , 5 3 , 5 9 7 4( 1 9 8 8 ) .

lc. ( Ii.)iSbOTf (1). Preparation.l r:.. .llt (1), amines (PrimarY and a..,'hrrls.The reactionwith terminal 1 ;-,rclvage almost exclusively.No o;.: rr cd. (C6H'){SbIor (CoH,).rSbCl x .,.irled advantageof solubility in

(R/S= 94-96:6-4) ' H. Kunz and W. Pfrengle,Am. Soc.,f10, 651(1988) 'R. Urban and I. Ugi, Angew.Chem.Int. Ed.,14,6l (1975).

Thiolacetic acid, CH.COSH. Chiral dithioacetals.t In the presenceof TsOH or ZnI, an aldehyde, a thiol, and thiolacetic acid react to form a mixed acyldithioacetal (l). These products can be deacylated (KrCO., NaOCH,, or CH.Li) and then alkylated to provide chiral dithioacetals(2).

OH I!CO,or CH,Li

N(C,HJ, r , r/^*N(C"H.), " ' | OH | ' . . , t 1 .2. 9 52, 1( 1 9 8 5 ) . (1989) Letters,30,739 !. i :,uhedron

R,X --=----

+ HSR'cH3cosH RrcHo + #*'-"nat"o"n' 65-nqa \SRt

50-95% .

I

-SR3 R'cH-

\sR' .,

30E

Thiourea-Titanium(IV) isopropoxide

Optically activedithioacetalscan be preparedby use of the thiolacidprepared acid by reactionwith oxalyl chloride and from (R)-( - )-ct-methoxyphenylacetic then with NaSH. This thiolacid reactswith an aldehydeand a thiol to form the separable mixed thioacetalscorrespondingto l as a 1:1 mixtureof diastereomers, by chromatography(-757o yield). Theseare convertibleinto opticallyactivedipurity. thioacetalscorrespondingto 2 with no lossof diastereomeric rJ. Y. Gauthier, Letters,29, T. Henien,L. Lo, M. Th6rien,andR. N. Yotng,Tetrahedron (1988) andR. N. Young,ibid,29,6733 M. Th€rien, J. Y. Gauthier, 6729(1988); Thiophosphorylchloride, S= PCl,. Cyclothiophosphorylation.rThe diasteromersof nyo-inositol-1,2-cyclothio(1) phosphate(2) can be preparedby reactionof 1,4,5,6-tetraacetyl-myo-inositol of KCl. addition with thiophosphorylchloridefollowed by deprotectionand

Tin-Aluminum, Sn-Al. Reaction of RCHO vidt C selectiveand threo-selectivesh aldehydewith cinnamylchlond detectableproduct. This diastc aromaticaldehydes.The rertx only the 1,2-adducts,again *rd with I provides phenylpropanal with anti-selectivityat the C-(

(I) RCH:CHCHO + C,[CH:

CH.

t " 0r) c5rtcHcHo+I .-> gt

OH RO RO

1) s=PCl!,cHfN, PY 2) TEATIIIOH 3) KCI

OR

,

I J. M. Coxon, S. J. van E;"k. and I

2n%

I,R=Ac

s tl

K .rP'od ?

HO HO

+

OH endo-2

Ho-T-----/4 HojLa---__Jf,( OH exo'2

Tin(II) chloride,SnCl'. Ally lation with ally lk .LN anda traceof a palladiumcatdlt are convertedinto an allylrc r aldehydesto give homoall;-hc (DMl. I methylimidazolidinone requires a higltc possible, but is reaction SnCl,in this allylation

I C. Schultz. (1988)' Letters,29,3919 Tetrahedron andB. Jastorff, T. Metschies, (l) CH':Q11CHrOH Thiourea-Titanium(IV) isopropoxide. 2r3-Epithio alcohols,t Thioureais knownto convertepoxidesinto episulfides. In the presenceof Ti(o-l-Pr)0,trans2,3-epoxyalcohols(1) alsoreactwith thiourea (equationI). to provideepithio alcohols(2) without lossof enantioselectivity

.un-c,n,So" d%::l I (2S,35, 98% ee) rY. Gao and K. B. Sharpless, l. Org.,53' 4114(1988)

n-c,n,,
'\@r

1

Example:

+ CH' -f C5H5CHO

-

G

Tin(II) chloride

T.,:f J h! use of the thiolacid prepared ;'. :c.rction with oxalyl chloride and b .,: .ridehvdeand a thiol to form the : - :)\ture of diastereomers,separable rrr . 'nrertible into optically active dii : . : : . r \ t C r e O m e rpi U Cr i t y . ;-.: L \. Young Tetrahedron Letters,29. R , \ \ , , u n g .i b i d , 2 9 , 6 7 3 3( 1 9 8 8 ) .

e : ::.r: of nyo-inositol-1,2-cyclothio, : . l.-i.6-tetraacetyl-myo-inositol (1) f :: ,tection and addition of KCl.

30!)

Tin-Aluminum, Sn-Al. Reaction of RCHO with culrrcV=cHCHzcl.t This reaction can be regioselectiveand threo-selective when mediatedby Sn and Al. The reactionof benzaldehydewith cinnamylchlorideprovidesthe anti-Itomoallylic alcoholas the only detectableproduct. This diastereoselectivity obtains generallywith aliphatic or aromaticaldehydes.The reactionwith enalsunder the sameconditionsprovides only the 1,2-adducts,again with dnfr-selectivity(equationI). The reactionof 2phenylpropanal with l providesa mixtureof homoallylicalcoholsin the ratio 3:1. with anli-selectivityat the c-c bond formed in the reaction(equationII).

(I) RCH--CHCHO + C.HTCH:CHCHzCI s"'Ar' R\ZV\ZCH2 I

9uHt

OH

CH"

t "

GI)qH,CHCHO+1----+

qH,

9H, 9.H' -A,zcH,

+

r.|U

9H, 9,H, t l crHr/"-/\y'wn'

ou

( 3 :l )

'J. M. Coxon,S. J. vanEyk,andp. J. Steel,Tetrahedron.45, (1939). 1029 S

}.rl

tl

P

/.

to

.-P'KO

-4 --ion *

d?

HO HO

l : l

OH exo-2

Tin(II) chloride,SnCl,. Allylation with allylic alcohors.t In the presenceof at reastr equiv.of Sncl, anda traceof a palladiumcatalyst,clrpd(c6H5cN),,ailyl alcoholsandailyl acetates are convertedinto an allylic metal, CH,:6116"2Sn(IV), that can react with aldehydesto give homoallylic alcoholsin reactionsconductedat 25" in 1,3-dimethylimidazolidinone (DMI, 11, 202), (equationI). Similarallylationof ketones is possible,but requiresa highertemperature.SnF,and sn(oAc), cannotreplace SnCl in this allylationreaction.

h r : . , : L e t t e r s , 2 9 , 3 9( 11998 8 ) . (l) CH2:Q11CHrOH

r - : ' c()nvertepoxidesinto episulfides. 1r , ,,,hols(l) alsoreactwith thiourea (equationI). o: :r.rntioselectivity

Pdlsncl >

lCH,:g116",Sn(IV)l #ft+

CH,:6116n,i"*

Example:

C6H5CHO+ CH'\4\/OH

P{lfL

'

OH

=,.,u,,Xilo" 2 (2R, 3R, 98Voee)

oH

RcHo

I

u,c]

?H

cun, * H,cfcuH,

CH,

CH, 49:51

310

Tin(II) chloride-Chlorotrimethylsilane

of I r3-dienes.2 These1,4-endoperoxides D eorygenationof 1,4-endoperoxides are reconvertedto 1,3-dienesby Snclr.

quH,

C^H.

io l l

t"-

3"'h

l +

v,o I

CuHt

C.H.

A 2 I + l

vIo

k

CuH,

CuHt l5Vo

fu", 116

(33Vo)

?,"' 4-\

v*'v c.H,

' T. Mukaiyama, K. Wariishi.Y. Sarto.I ( 1e88).

cuH,

rY. Masuyama, J. P. Takahara,and Y. Kurusu,Am. !oc.,110,4473(1988). 2 S. Kohmoto, S. Kasai,M. Yamamoto,and K. Yamada,Chem.Letters,1477(1988).

Tin(II) chloride-Chlorotrimethylsilane. Aldol-type reaction of acetals with alkenes, Mildly activated alkenes can undergoaddition reactionswith acetalsin the presenceof ClSi(CHr)sand SnClz, as in the reactionwith dihydropyran.However, the correspondingreactionwith styrenerequiresa full equivalentof ClSi(CHr),and a catalyticamountof SnCl,for a satisfactoryyield.

A I \o/

c6H5cH(ocH)2 -- c.ll;

crs(cH,)I ffCuH, C.H,CH(OCH,), * 84% | | ll+ \oAo." |

?'",

2

cl + I + ClSi(CHrt CTHTCH:CH, #

ocH"

CrHr$CrU,

Thesereactionsmay involve the activespeciesa.

Tin(I9 chloride. Regio selec tive O -debenzylatia is the most effectivefor this readrc BzlO BzlO BzlO

Bzl( Bzl( -cHac\.2s' ltr

OBzl OBzl OBzl

hr.) 1 TiCL(O.75 1 SnCl.(7 hr.) 2 SnClo ;OBzl fOBzl LOBzI

;OBd FOH t-OBd

SnClo

86%

ricl

6E%

requiresat least three groupscape order of complexationis priman > 2- O -Organosily I g lycosidcs; CI densationof furanosidesand orgnn furanosides.Thus the reactionof lh

Tin(lV) chloride

Ecnes.zThese1,4-endoperoxides

+ (cHr),SiocH, t' ceHscHaot"' c6H5cH(ocH:)z -cl

CuHt

.

311

(.'Jl

O

v

f .ocH;l | ^-./"---'l
CuHt ilcc)

lT. Mukaiyama, Leuers,lT0l andS. Kobayashi,Chem K. Wariishi, Y. Saito,M. Hayashi, ( 1988).

1988). \ . 1 1 0 , 4 4 7( 3 (1988) vJ.t Chem.Letters,1477

Tin(IV) chloride. Regioselective O-debenzylation. Of a numberof Lewis acids,SnCL or TiCl is the most effectivefor this reactionwith polybenzylatedsugars.The substrate

Bzro--l rs. \{ildly activatedalkenescan and SnCl' prr'ienceof ClSi(CH3)3 lr. :hc'correspondingreactionwith arj a catalYticamountof SnCLfor

ctLcL,25"-

BzlO--.1

l--oert l-onrt l-oBzl I TiClo (O.75 hr.) 1 SnClof hr.) 2 SnClo

1-OBzl

?'", ::

il

iicuH,

(oAo.", 7

. i

cl

r

ocH"

l

coH,AicuH,

ifra\ a.

-l--oezt LOBzI SnClo TiCl"

BzlOl

BzlO--1

BzlO-1

BzlOr

Bzlo-l

Ho-i

Bzlo--l

HOi

BzlOi

HO--l

[-osrt' Foszl LoBzl

FoBrl |_onzt LoBzl

65Vo 577a

19Vo 234o

FoH FoBzl LoBzl

;OBzl

FoH LOBzI 86Vo 68Vo

requiresat least three groupscapableof coordinationwith SnCl. or TiCL. The order of complexationis primary > secondary) tertiary alkoxygroup.r 2-0-Organosilyl glycosides;C-furanosides,2SnCl (l-2 equiv.) effectsconbearing a leavinggroup to give Cdensationof furanosidesand organosilanes gives 1 with allyltrimethylsilane furanosides furanosides.Thus the reactionof the

3t2

Tin(IV) chloride

However,the re(2), but without stereoselectivity. or C-furanosides C-glycosides showsconsiderableselectivity.The difference action with a chlorodimethylsilane

HOwCH3

o\

*'#*,f aTuq \-' \/ I

Sncl.

BzlO OBzl

OCH,+ CH,:CHCHTSi(CEL W RO CH,CH:CH' I

,ro "4*""4ru.",,,., f CH,CH:CH'

Another example:

OH 3 ( F / o- 6 5 : 1 ) in the latter reaction,which is ascribedto formation of a 2-O-allyldimethylsilane 3' then rearrangesto the 1,2-trans-C-glycoside Another examPle:

*o/o\o."

\j?-""'

* t",0si(cH3)'o

sd !

BzlO OBd

.s.:''

Acyl isocyanates.aSnCLis the bcg, by reaction of ATCOCI and NaOC\. r ' is the preferredsolvent. chlorobenzene acyl chlorides.

RO

H. Hori, Y. Nishida,H. Ohrui.andH \lc1 : O. R. Martin,S.P.Rao,K. G. Kurz.andH ' M. SworinandW. L. Neumann, J. Ore . Sl ' M.-2.Deng,P.Caubere, andS J. P.Senet.

OR

Cyclizationofacyclicacetals.sReactionofthel-hydroxy-1-vinylacetal(1) -7go providescis-hydroindenes 2 and 3, which with inclo (1 equiv.) in cHzCl: at are convenientprecursorsto the dione 4'

Tin(II) trifluoromethanesulfonlte. Enantioselective M ichael addida rl enonescan proceedenantioselectivelr in the presenceof a chiral diaminesuct

Tin(II) trifl uoromethrnesulfonate

te:r '.clectivity. However, the rele:.,^,e selectivity.The difference

n.a_.5 ." ,t._-+

BzlO OBzl

o- rr'o\ \oR -

mFe,,.m,,, 7e

)-CH,CH:CH,

/

IlrI..parc

f,ziic

o\a-cH'

OH 2 ( a / p- r : l )

l \

t H

) b

4 Another example:

o\a-cH'

a:. rn the latterreaction,which

*q",, Acyl isocyanates.aSnClois the bestcatalystfor preparationof theseproducts by reactionof ArcoCI and NaocN, with znCr, being a closesecond.r,z-Dichlorobenzene is the preferredsolvent.yields are lower in reactionsof aliphatic acyl chlorides.

11, Cl lf15

c6H4cH3

thc 1-hydroxy-1-vinyl acetal(1) c:.-hvdroindenes 2 and 3. which

I H. Hori,Y. Nishida, H. Ohrui,andH. Meguro, J. Org.,54,1346(1989). rO. R. Martin,S.P.Rao, K. G. Kurz,andH. A. El-Shenawy, Am. Soc.,110,3698 (19Sg). 'M. Sworinand W. L. Neumann, J. Org.,53,4894 (l9Sg). ' M.-2.Deng,P.caubere, p. J. Sener, andS. Lecolier, Tetrahedron,44, 6079(19gg).

Tin(II) trifl uoromethanesulfonate. Enantioselective Michael additions.t The addition of tin(Il) enolates to enonescan proceedenantioselectively when activatedby trimethylsilyltriflate and in the presenceof a chiral diaminesuchas l.

Tributyltin fluoride

Tin(II)

'(o

I, aldehydesundergoasymmetricaldol rr ee. The activespecies(2) is presumedro Sn(OTf)r,which unlike the individualcq

d^fi{)o)

-os(cHJ, ": ,

C6H5CHO+CH2:C(

sn(orr),,r ? ? ? c,u,8-ry g +cu,8cH:cHCcHs #

3

\-J

(CH").CHO+ 3 + q

o

*Ao + syn-2 LJ 9 5 : 5 anti-2 (93Voee\

fi

sn('rr),,r?

?

i!% cu/\ scn,+ cH,8u:cHC.H,

f'"' f,

cnlAlscH,

2-(1'-Hydroxyalkyllbutenolides.2The tin(Il) furanolates(2) generatedfrom (L) react with an aldehydeto give a 2-substitutedbutenolide(3) 2-(5F1)-furanone as the major product. Similarresultsare obtainedwith boron furanolates.

I

-r l-m sn(orr)r)L("\-'"ol

-

rO l


t

\Aocn

3c (2t 3D15

presentin only 10mole 7a.Reactionssrrh (84Vaee), but B-substitution of the enaldr

#

)

' t a

This catalyticaldol reactionhas been actions catalyzedby the chiral acvloxvbo and Bu3SnFlead to opticallyactiveprodu CH.O " l

70Vo ee

R \oAo

-SCJT

_x;;

/

\oAo

3

\

+

7:l

CH,:6(CH;. O

ar",,.-{O\O OH 4

I T. Yura,N. Iwasawa, (1988). ChemLetters,1021,1025 andT. Mukaiyama, K. Narasaka, ' C. W. Jefford, (1988)' "I.C.S. Chem.Comm.,1595 andJ. Boukouvalas, D. Jaggi, Tin(II) trifl uoromethanesulfonate-Tributyltinfl uoride. Aldol reactions. In the presenceof thesetwo promotersand in combination (13, 302), with the chiral diamine (S)-1-methyl-2-[(piperidinyl)methyl]pyrrolidine

I S. Kobayashi andT. Mukaiyama. Chembt : K. Furuta,S. Shimizu, Y. Miwa.andH Yer

Titanium(0). Low-valent complues. Ponsand Sra valentcomplexesof transitionmetals.Far (301references). I J.-M. Pons and M. Santelli. Tetrahedron. tll-

Tit&nium(O)

315

1.,aldehydesundergoasymmetricaldol reactionswith silyl enol ethersin78-95Vo ee. The activespecies(2) is presumedto be a complexof the amine,Bu.SnF,and Sn(OTf)r,which unlike the individualcomponents,is solublein CHzCL.' _OSi(CH3)3

csH5cHo* gHt:cl5c,H.

2.clLcl, _78. >

i1%

o o H i

l

:

c,H,s\ic.H, ( S ) , 8 2 7 oe e

o

o o H (cH3)3cHo * 3 n*c(cH3)3 crH,sA

?

AnAo

n, \J

95:5

*-2 937oee)

t,,\

6959o e.e\

+ syn-2

i"r'frscH3

This catalyticaldol reactionhas been extendedto c,9-enals.2Thus these re3a and 3b in addition to Sn(OTf), actions catalyzedby the chiral acyloxyboranes products in as high as 97Voee evenwhen 3 is and Bu:SnFlead to opticallyactive

COOR {

,,'N2'cooR I I

r.rtes (2) generatedfrom ub.trtutedbutenolide(3)

ocH3

OH

3a (2R, 3R) 3b (2S,35)

x-ron furanolates.

presentin only 10mole 7o.Reactionswith acroleinare slightlylessenantioselective to2Vo ee. the enantioselectivity (84Voee),but B-substitution ofthe enal decreases

cu,:s(cH'

*

3a, CH?CL + 85%

CH, C,H,,

'

o

H 4

I S. Kobayashiand T. Mukaiyama,Chem.Letters,297(1989). r K. Furuta,S. Shimizu,Y. Miwa, and H. Yamamoto,J. Or8.,54' 1481(1989).

1025(1988)' r. !,Lrrers.1021' | ,,:,,t..1595(1988)'

Titanium(0). Low-valentcomplexes. Ponsand Santelli'havereviewedreductionswith lowvalentcomplexesof transitionmetals,particularlythoseof titanium and vanadium (301references).

rnorersand in combination rthi ilpl'rrolidine (13, 302),

I J.-M.PonsandM. Santelli,Tetrahedron,44, 4295(1988).

316

Titanium(Ill) chloride-Potassium/Graphite

Titanium(IV) butoxide/Copper(I) chloride. Rearrangementof proparyylic alcohols to enals or enones.r In the presence of a carboxylicacid (generally-7 equiv. of p-toluic acid or crotonic acid), propargylicalcoholsare rearrangedto enalsor enonesby Ti(OBu). in combination with CuCl, both in about 0.02 mole Vo.Silver trifluoroacetatecan replaceCuCl, but yields are lower. The acid is not mandatory,but can increasethe rate and yield.

*"?":_'i'l?"", t"XJrl", tttu

|

' D. L. J. Clive, K. S. Keshau M. Majewski, P. C. Anden< ( 1988).

Titanium(Ill)

chloride-Sol

)c = Norr*)6q

If this reductionis conduc is reducedto an amine tre particularlyusefulfor comp

I J . P . L e e d sa n d H. A. Krnr-.

'rcHo

9cH,

cH3

Titanium(III) chloride-Zir 1,2-Cy cloa lkanedi ols. paredby reactionof o.
o CH,C-CCIIOH

tl

A

CHTCCH:Cn,

' P. Chabardes, 29,6253(1988). Letters, Tetrahedron TiCl.-CrK. Titanium(I[) chloride-Potassium/Graphite, McMurry coupling. Clive and co-workersrreport that a modStereoselective ified McMurry reagentpreparedin DME with crK and Ticl. (-2:I) can effect couplingof keto aldehydes.Thus the key stepin a synthesis highly stereoselective

CH,

of ( + )-compactin(3) is the couplingof the keto aldehyde(1) to give the A/B ring system(2). Using the modifiedTi(0) reagent,the asymmetriccenter adjacentto the ketoneis not eoimerized.

I

This cyclizationwasused B (l) (laststep,46% f ieldp

I

' J. E. McMurryandJ. G. Rx! ' J . E . M c M u r r yJ,. G . R i c o . u

"t'yAg CH,

(+)-3

Titanium(IV) chloride. Michael additions of tc equiv.)theseacetalsunderg intermediate.

Titanium(IV) chloride

a enones.r In the Presence a.r\i or crotonicacid)' Prorr frtOBu)r in combination can replacecucl, r\r.lc!'tate the rate and increase rt i.rn

-ocH3

K..

6-cHo CHt

l:CH:

..K rePortthat a mod1* rrrkersr .'nJ TiCl. (-2:I) can effect ru. the key stePin a synthesis

3r7

G. V. J, da Sielva. l D' L. J. Clive,K. S. Keshava Murthy,A. G. H. Wee'J. SivaPrasad' R. D. Haugen,andL' D Heerze,Am' Soc''110'6914 M. Majewski,P. C. Anderson, ( 1988). Titanium(Ill) chloride-Sodium cyanoborohydride. ___>)cNHr. Ticls is known to reduceoximesto imines(4,506). )c = 71Qlt If this reductionis conductedin the presenceof NaBH.CN (buffered)'the imine is reducedto an amine before it is hydrolyzedto a ketone.This mild method is groups.' particularlyusefulfor complexsubstrateswith acid- and base-sensitive rJ. P.LeedsandH. A. Kirst,Syn.Comm.,fE' 777(1988)' Titanium(Ill) chloride-Zinc/coppercouple. cyclicpinacolscan be pre1,2-Cycloalkanediols. Six-to fourteen-membered ( 1 : 9) in DME at 25'' couple ZnlC]u and TiCl. with a,o-dials of paredby reaction lrars-productsprebut rings, to eight-membered in sixpredominate cls-Pinacols members.r 10 or more of dominatein rines

cHo ;'F", cHo

.oH

ssEo

cis,lW% sarcophytol sesquiterpene This cyclizationwasusedto obtainthe 14-membered B (1) (last step,46Voyield).'

cH(cH3)' c h r J c( 1 ) t o g i v et h e A / B r i n g brnrnretriccenteradjacentto CH,

c rJ. E. McMurryand J. G. Rico, Tetrahedron Leuers'30'1169(1989) r J . E . M c M u r r yJ, . G . R i c o ,a n dY . S h i h i, b i d , 3 0 . l l 7 3( 1 9 8 9 ) .

rCti

Titanium(IV) chloride. Michael additions of ketenealkyl silylacetals.t In the presenceof Ticl, (1 equiv.) theseacetalsundelgo Michael addition to ethyl propiolatevia a titanate intermediate.

3lE

Titanium(lV) chloride

-OCH, (CH.),C:C1-osi(cH3)3+ Hc-ccoo",n,

(cH,),c(coocH'

#

coocrH5 (E)'r00Vo

Fries rearrangement.' Fr at 120'resultsin a mixtureof < productof ortho rearrangerne of the isopropylgroup. Hoso 2 in 79% yield.

I

o I

lricr4

-coocH.

\<

(cH3)'C(

t-Pr

cooc2H5 = (Flz) 99:l of zirconium(IV) The samereaction,but in the presenceof a catalyticamount chloride,resultsin [2+2] cycloaddition'

H,9 9cH, osi(cH3)l .ffli r ",.-t | |

..ocl3

+ H C - C C O O C z H s +loqa ( C H " ) , C : --osi1cH,), C(

f=J i l l

\.,4a

Br

\

I

Intramolecular M u*aiyet cyclizesto the tetrahydrofura CHrCl2at 0". The product rs q

-aooarn,

Conjugatecrotylation.TheHosomi.Sakuraireaction2hasbeenextendedto In this casethe stereowith crotylsilanes.3 .onluguie .rotylation of cyclohexenone group and to a less selectivityis highly dependenton the geometryof the crotyl show high erythro-selecextenton the groupson silicon. (E)-Crotyltrialkylsilanes (equationI)' (E)-(crotyl)methyldiphenylsilane with tivity, being highest O

o)

CH.

+cHs^siMe(CuH,), ;-

0

o\r-TA)t"' (/ ( 1 5 . 61:)

The highestthreo-selectivity (Z)-Crotylsilanesare inherently mlldly threo-selective. but 2 equiv' of Ticlo is substituent, alkoxy an can be obtainedwhen siliconbears reaction(equasecondary a of because then required,and yieldsare only moderate tion II).

o

(rr)A (--l

-

CH" I \isi(cH3)2oc2H5

Ticl. 65%

(11.2:1)

Carboxamidesfrom CrII sC boxylicacidsdirectlyratherrha and N(CrHr), is carried our rn primary amine, BF, etherarers equal to BF, etheratein rert advantagethat the rate of amx Polyarenes,T TiCl. effe
Titanium(IV) chloride

:.._ !--;

-coocH3 (CH3)rCi \ coocrH5 (E), rffi%o

319

Friesreatangement,4 Fries rearrangementof the phenyl esterI with AlCl. at I20" resultsin a mixtureof eight products,only one (2) of which is the expected productof.ortho rearrangement. The othersareformedby migrationor elimination of the isopropylgroup. However, rearrangementcatalyzedby TiCl at 120"gives 2 in 79Voyield.

o tl /.coocH3

H . C \

B

ricl., 120'

T

coc6H5

t-h

+

79%

cooc,H,

CH,

CH,

rElZ)= 99:l tic amountof zirconium(IV) c.:i.rlr

H,9 9CN,

..

Intrqmolecular Mukaiyama aldol condensation.s The silyl ketene acetal I cycfizesto the tetrahydrofuran2 in 32Voyield on exposureto TiCl, (1 equiv.) in CH2CI,at 0". The productis convertibleinto 3, an analogof cycloleucine.

H,C-*OSi(CH3)3 t..-----coocrH, l

BzlO"C NPht TicL,0'

Ir.ri rcaction2has been extended to ) l \ . . r l l n e s . 3I n t h i s c a s et h e s t e r e o | ,,: rhc crotYl grouP and to a less \r .'rl.rnesshow high erythro-selech;::r i.ilane (equation I).

-g% ocHro(cHr)rocu,

X LJ t

I ll n' 58%| ^.

l"'\/'n'

*

/.CH,

u

HOOC NH" V \\__o /

( 1 5 . 61: ) ri:rr c. The highest threo-selectivity iu\.rrtuent. but 2 equiv. of TiCL is ?u.c Lrfa secondary reaction (equa-

H

QH, :

o1,2.--f.A-ZcH,

. : - l l \-/ (11.2:1)

3 Carboxamidesfrom C,IITCOOH.6 Carboxamidescan be preparedfrom carboxylicacidsdirectlyratherthan via the acidchloridesif the reactionwith an amine and N(crHr), is carried out in the presenceof a Lewis acid. In reactionswith a primary amine, BF. etherateis completelyineffective.In contrast,TiCl. is about equal to BF, etheratein reactionswith a secondaryamine and has the further advantagethat the rate of amidationis fasterwith ricl,, than with BF. etherate. Polyarenes.TTiclo effectscondensationof the enol silyl ether of a cycloalkanone with 2-arylacetaldehydes to provide a product that can be dehydrogenated to an angularpolyarene.

320

Titanium(IV) chloride-Lithium aluminurnhydride

I W. R. Dolbier,Jr. andC. R I

,,.,., 62%

()

*

(cH3)3siov Acylalkylationo! arcnes.t In the presenceof TiClo,arenesaddto nitroalkenes substituted to form a nitronateadduct,which undergoesa Nef reactionto provide

Titanium(IV) chloride-H4l CoupI ing of a Id i mi ncs.' reductivecouplingof aryl ald of.meso-and d/-isomen

arenes.

No,

C.H.CH=

I C. Betschart. and B. Schmidt.

r*fno. o

Titanium(IV) chloride-Trr 12+2lCycloaddition n presenceof 1 equiv. of a Tr methyl styrenesreact uith . ( (1) or dihydrobenzofurans rangementof l. The compo of cycloadduct.TiCl. farors quiresa mixedTiCl.-Ti(Grextentthe stereochemisho runcture.

c.HncHr-p I A. Quendoand G. Rousseat,Tetrahedron Letters,296443(1988)' 2 A. Hosomi and H. Sakurai,Am. ioc.,99, 16'73(1977)(lf ' 529-530)' 3 T. Tokoroyamaand L.-R. Pan, Tetrahedron Letters,30' 197(1989)' I R. Martin and P. Demerseman,Synthesis' 25 (1989). s D. M. Walker and E. W. Logusch, Tetrahedron Letters,30,1l8l (1989)' 6 A. Nordahland R. Carlson,Acta Chem.Scand.,B42,28(1988)' ? P. Di Raddoand R. G. Harvey, Tetrahedron Letters,29,3885(1988)' " K . L e ea n dD . Y . O h , i b i d . . 2 9 . 2 9 7 7 (1988). Titanium(IV) chloride-Lithium aluminum hydride' 6' 596' Chlorofluorocarbene.t This carbene can be obtained by reaction of CFCI, (b.p. 23.7') with the titanium speciesobtained from TiCL and LiAIH' (1:1)' It converts alkenes to chlorofluorocyclopropanes at 0o in generally good yields.

4-cHpc6H( EIZ = l4:l

+ CH,

CH, CH,

("'

CH,

CH'

cFcl.

(CH'),C:CHCHT4L

o

F

CH'

*d',,*,,'&"'

A Yo

*ll

cH!

4-CHTOC.H;"

Titanium(IV) chloride-Titanium(Iv) isopropoxide 'W. R. Dolbier, Jr. and C. R. Burkholder,TetrahedronLetters,29,6749 (1988).

l

addto nitroalkenes arenes f Tr('1,. provide substituted to rcaction ei

Titanium(IV) chloride-Magnesium, 7, 373. Couplingof aldimines.t The Ti(II) reagentobtainedfrom TiCl. andMg effects reductivecouplingof aryl aldiminesto 1,2-diarylethylenediamines as a L : 1 mixture of meso-and d/-isomers.

.| .-/,oricl3

-./'-o-

coH,cH:fr1c n), #

|

|

\

tcH,),7 c.Hf,.-c.H' N(C4),

I

f Jc.u.c4-p; J

_

= l:l esoldl rC. Betschart, B. Schmidt, andD. Seebach, Helv.,71,1999(1988).

e4% lHp'

o

Titanium(IV) chloride-Titanium(IV) isopropoxide. 12+2lCycloaddition or 13*2lcycloaddition of alkenesto quinones.t In the presenceof 1 equiv. of a Ti(IV) catalystcomposedof TiCl.,and Ti(O-l-Pr)., Bmethyl styrenesreact with 2-alkoxy-1,4-benzoquinones to form crs-cyclobutanes (1) or dihydrobenzofurans (2), which can be formed by an acid-catalyzed rearrangementof 1. The compositionof the Ti(IV) catalystlargelycontrolsthe type of cycloadduct. Ticli favors[3+2]cycloaddition, whereas[2+2]cycloaddition requiresa mixedTiCl,,-Ti(O-r-Pr)o catalyst;the rate of reactiondeterminesto a large extentthe stereochemistry of the cyclobutanes, which are invariablycls at the ring tuncture.

lCuHnCH'-P F L-.1 (l9tt8).

r 11.529-s30). - u . q 7( 1 9 8 9 ) . r ' . - u . 1 1 8 1( 1 9 8 9 ) . E :. (1988). . $ r s 8 5( 1 9 8 8 ) .

id€. 6. 596. E ,'i-tained by reaction of CFCI. :r,,nrTiClr and LiAlHr (1:1). It in generallygood Yields. rt

l.6rI

+

4-CH3OC6H: EIZ = l4:l

CH,

'CH, r/Cl

OCH, 1icr.,r1o-i-ny.

("t'

+ CH,

CH,

F 2.2:'l

dl"

cH3\

,Rotr

4-CH,OC,H;"( Il I .o4r4ocHr

CH,

+ 4-CH3OC6H;

2 (72Vo)

| ( 1 2 9 o>,1 9 : l )

ocH3

ln

Titanium(IV) isoProPoxide

4",\,

OBzl rrcr.-r(o-t-n).

CH,

r/' 3.4-(CH3O)2C6 (ffi=22:r)

p-Toluenesulfonylrzilb. a-Alkyl-P-keto ar,i in high rx 1,3-diketones to form , rearrangement secondaryamineto.pro

1 . 8 I:

*

49q.

CH,

CH,

o ll

o ll

r.\

cHycH,;

+

OBzl 34:1 3,4-(CHrO)rCuH;

3,4-(CH3O)'C6H;

rT.A.Engler,K.D.Combrink,andJ'E'Ray'Am'Soc''110'7931(1988)' isopropoxide,Ti(O-l-Pr). (1)' Titanium(IV) ^*';;;; granteda patentfor prepa"Lonou.' A few yearsago Mihelichrwas rationofepoxyalcoholsbyphotooxygenationofalkenesinthepresenceoftitanium orvanadiumcatalysts.Adametal.2haveinvestigatedthisreactionindetailand f l n d t h a t T i ( I V ) i s o p r o p o x i d e i s t h e c a t a l y s t o f c h o i c e f o r e p oalcohols' x i d a t i o nwhen ofdi.,tri-' and cyclic.,to provide epoxy and tetrasubstituteduk"n"r, acyclic The canbe diastereo-and enantioselective' appliedto allylic uftortof',it'" '"uttion hyallylic an provide to in two steps:an ene reaction reactionactuallyproceeds Ti(o-iby catalyzed jri."r""t*ular oxygen transferof droperoxidefollowed o, stereoepoxidationand can be highly Sharpless of Pr).. The latter step is a form selective.

9ffg' (CH,),c:cHu-nu

t"'04:{" (95:5)

OH

i-

A---fto \./ \,,.,,

6o9o

OH

\ . .(-,'JJ Q%)

(1983)]' 4'345'984[C' A ' 9E'i25739c "itttiotto' I E. D. Mihelich, U' S' Patent ti' witt' Am' Soc" 1ll' Staab"and E' v''l-uttt'ini' 2 w. Adam, M. Braun' "'

203(1e89).

I R. M. Moriarty. B. R & : J. Cossy, D. Belotti..{

Trialkylchlorosilenes. Coniugate sdditiq rate and stereoselecti studiedin detail br r-: catalyzedreactionof Gt in about equalamounl the reactionresultsin effect is particularll' rru with high E-selectivttl (CH.)iSiCl also imP agents.

I S.Matsuzawa, Y. HonE

Trialkylstibines. Thesc RMgX with Sbcl.. p-Hydroxy kcton with aldehydeswhich i as catalyst. The fun'c reouiredin reactionsr

Trialkylstibines

ln

p-Toluenesulfonyl azide,TsN.. a-Alkyl-p'keto amides. Tosylazidereactswith 1,3-diketones to give2-diazo1'3-diketones in highyield.'Theseproductson irradiation(254nm) undergowolff rearrangement to form q.-ketoketenes(a), which can be trappedby a primary or secondaryamineto provide a-alkyl-B-ketoamides.2

.'---._.

o

o

o

""AA.",7c"lfc", rsN.

ll

o ll

*Fry;"l +N,

N2

lF

\ , , ( . 1 1 0 , 7 9 3 (11 9 8 8 ) .

88%JrqNc4c=cH

o o i l t l h!: \\as granted a Patent for PrePar.l .,ikenesin the presenceoftitanium rc.ir{.rted this reaction in detail and o! .fi(,ice for epoxidation of di-, tri-, ',, provide epoxy alcohols.When [i I Jr.,.lc'reo-and enantioselective.The lnL r..rction to provide an allylic hyilsic: ,rf oxygen catalyzed by Ti(O-ilrrJation and can be highly stereo-

""'x_H" n

O

H

(95:5) OH

I

>\) + (/ l.-.

rr I

Cn, I R. M. Moriarty, B. R. Bailey, III, O. prakash, andI. prakash, Am. Soc.,10Z, 1375 09g5). I J. Cossy,D. Belotti,A. Thellend, \ andJ. p. pete,Synrfresrs, 720[9gg). Trialkylchlorosilanes. Conjugateadditions of organocoppers. The beneficialeffect of R.SiCl on the rate and stereoselectivity of conjugateadditionof organocopperreagentshasbeen studiedin detail by Nakamuraet al.t rn the absenceof (CH.),SiCr,the coppercatalyzed reactionof Grignardreagents to enonesgives1,2-and 1,4-adducts usually in aboutequalamounts.Addition of l-2 equiv.of both (CH.).SiCland HMpT to the reactionresultsin almost exclusive1,4-additionat an acceleratedrate. This effectis particularlymarked in addition to enalsto give enol silyl ethers,usually with high E-selectivity. (CH.).SiCl also improvesconjugateaddition of stoichiometricalkylcopperreagents. I S' Matsuzawa, Y. Horiguchi, E. Nakamura, andI. Kuwajima, Tetrahedron,4s, 349(lgg9).

^

(7%) "

CHMNHCH,C-CH

. ; . : . r 9 c( 1 9 8 3 ) 1 . Staab,and B. Will, Am. Soc.,lll-.

Trialkylstibines.Theseorganoantimonycompoundsare obtainedby reactionof RMgX with SbCl.. p'Hydroxy ketones.r o.-Bromoketonesundergoa Reformatsky-type reaction with aldehydeswhich is promotedby R,Sb but which is only possiblewith iodine as catalyst.The function of I, is probably for a Br/I exchange,since 12is not requiredin reactionswith ct-iodoketones.

34

Trialkyltinhydrides

o il

+ BurSb!I+ i-BuCHO + CH3CHTdCH,

o H o t t l i_su^}"".

+ (Bu,SbBr),o

I CH'

Br

synlani = 57:43

Tributylarsine, Bu,As (1). RCHO --->RCH=CHCO2CHy.| O uratedesterscan be effectedby reactro equiv.) catalyzedby zinc powder. Thrs heteroarylaldehydes.

o /--"'

t

+ p-BTC.H.CHO + Bu,Sb-ft,

l

RCHO + BCHTCOOCH,-! R = C.H, R = CHI(CHJs

n-BrCrHi

I Y. Shen,B. Yang,andG. yuan..l.C.S CiL

(synlanti= 7l:29) rY.-2. Huang,C. Chen,and Y. Shen,J.C.S.Perkin1,2855(1988).

Tributylphosphine-Zinc. Wittig-like reaction.t The reacrron promotedby Bu.P (1 equiv.)and Zn rl

Trialkyltin hydrides. Cyclopropropylmethyl radicals.r Generation of a radical center adjacent to a cyclopropane can result in ring opening of the cyclopropylmethyl system. This reaction can be used to convert allylic cyclohexenolsto alkylcyclohexenes,as shown for conversion of I into 3 via the phenyl selenide 2. When the cyclopropyl ring is

I Y. Shen,Y. Xin, andJ. Zhao,Terrahedro I

SeCuHt

OH

* .cr'i'lrjilY' A ;;ilrf,l: a\ -cr=*= '#9., +' ?''\4s,.,, :?J.-.,,t;.i vrr3

vrr3

cH,

r

I

CH3(CH),'CHO+ BrCtlCOOC{ -

cH,

cH,

2

3

ring expansionis a competing,but minor, pathway fusedonto a cyclopentane, (equationI). Photolysisof a benzoateor bromiderather than a selenidecan also

Tributylstibine,Bu.Sb. a,p-Unsaturated nitriles.t The rce and Bu.Sb (1 equiv.) resultsin theseunr /rcrs-isomers. n-C'H,,CHO+ CICILCN+ BurSb+ ncl tDla

SeCuH, BusSnH ,tv, 0'

+

86co

+

isomeric cyclohexene

8 4 :1 6

be usedto generatethe radical.The Simmons-Smithreagentis suitablefor cyclocan be controlledby the hydroxyl group. propanationsincethe stereochemistry Intramolecularcyclopropanation(1i1,52) is also useful. The advantageof this systemis the regio- and stereoselectivity. I D. L. J. CliveandS. Daigneault, (1989). l.C.S.Chem.Comm.,332

i Y.-2.Huang,Y. Shen,andC.

Chen.Srn C

Tributyltin hydride. Regioselective cleavoge of gcll.a{ methyl)cyclopropane is cleavedby Bu.So -CH"Br ' v

n

F F

BrJ.tl

^Ds.cJ{

Tributyltin hydride

() + (Bu'SbBr)P f^t", cH, _ <-

rl

o H o

RCHo+ BrcHrcoocH,-!g

l r l

- - uo, v ^ r rri\A 4 .

|

|

t \-/

n = C.tl,

l

RcHgcHcorcH3

80%

R = cq(cH,L

e3%

I Y. Shen,B. Yang,andG. Yuan,l,C.S.Chem. (1,989). Comm.,144

stnlanti= 7l:29) . ' r 51 .

';

Tributylarsine,Bu3As(L). RCHO --->RCH=CHCO2CHy,| Conversionof aldehydesto (E)-c,B-unsaturatedesterscan be effectedby reactionwith methyl bromoacetateand Bu,As (1 equiv.) catalyzedby zinc powder. This reaction proceedswith alkyl, aryl, and heteroarvlaldehvdes.

Tlibutylphosphine-Zinc. wittig-like reaction.t The reactionof an aldehydewith methylbromoacetate promotedby BurP (l equiv.)andzn (1 equiv.)provideso,B-unsaturated esters.

i .: :.rdrcalcenter adjacent to ;l,,rr()pvlmethylsYstem.This r .r.i.r lcvclohexenes,as shown \\ hrn the cycloProPYlring is

BulR Zn

g--+ CH3(CHr),.CHO + BrCtlCOOCq

Cq(CrD,oCH9CgCOOCn,

I Y. Shen,Y. Xin, and J. Zhao, (1988). Tetrahedron Leuers,29,6119 rh..-H. i

:-+

l

.,,\.,

l

CH"-l I .H"\-'4cHcL

CH,

3 n : \ t r n g . b u t m i n o r ,P a t h w a y t!r.(r thana selenidecan also

-

Tributylstibine,Bu.Sb. a,p-unsaturatednitriles.t The reactionof chloroacetonitrilewith aldehydes and Bu.Sb (l equiv.) resultsin theseunsaturatednitriles as a mixture of crs-and /rdrrs-isomers. n-C'H,,CHO+ CICHTCN + BurSb+ n-CrH,,CH:CHCN [+ BurSbCl,+ BurSb(OH)r] = 62:38) (translcis ' Y.-2.Huang,Y. Shen,andC. Chen,Syn. (1989). Comm.,19,83

isomeric cYclohexene

.-1 t6 I

h :..,rcnt is suitablefor cycle r' .r.i bl the hydroxYlgrouP. sr':,r, The advantageof thb ::' 'l9li9).

Tributyltin hydride. Regioselective cleavage of gem-difluoropropanes, 1,1-Difluoro-2-(bromomethyl)cyclopropane is cleavedby Bu.SnH/AIBN to 3,3-difluoro-1-butene as the ''CHrBr X F F

BurSnH

^'BN'c6H' ) cHrcFrcH:cH,

326

TributYltinhYdride

comcanbe usedto obtain(E)-difluoroallylic onlyproduct.rThisradicalreaction of the C'-C' bond'2 cleavage preferential io,i"i, o".".se of n "?V:" -

X

l

'

o

2-Deoxy sugars.a Reductiono bY rearraq Bu,SnHis accomPanied center.The migrationis cri-select br thr Bu.SnH is not accomPanied

CH, z *n-HexcH'cF'cH:cHcH: ' o

(E)

rnr i

-.&

qHCHrcHrC6H5 |

{

F

OAc

cH'cF'cH:cHcH2cH'c6H5 (E)

;

ToAc

F

In reactionswith atom tray{er cyclizations'3 Intramolecular l,S'hydrogen canundergo (14' 313.)'an originalvinyl radical low concentratlon,of tt'" iin nio"a" bond' which then " ne* taAicutfrom a C-H a l,5-hydrogenshift t" p'"l'i"t I)' undergoescyclization(equation E---,8

Bu'sncl.ArBN NaCNBHT' (cHt)rcoH

I fl) cH.oI - _/cHnrA6U,

FO

A c o (

OAc

AcO

Allyl radical cYclization.' A but can undergocyclizationu'rth I

)

HzC.r \ ,

/ \,/

CH,

G = coocHJ

) u

.",tn.i H2

fHCHrBr

(

l

\

""t * ABli

r

r

cH,oocncoocH3 (E or Z)

cH3ooc

""1

X

cH3O \

(

clocll

-CH,

CH: = 18:82) (cisttrans

c ExamPle:

om /

,),._)

v\,,cooc,H5

?cHrC6H5 cHrcoocrH5 s6%

\J = l:2'5) (cisltrans

^

/

;#("

Tributylrin hydride

com) r'rr.un(E)-difluoroallylic - (

bond.l

327

2-Deoxysugars.a Reductionof acetylatedor benzoylated glycosylhalideswith Bu.SnHis accompanied by rearrangement of the estergroupat c, to the anomeric center.The migrationis crs-selective. Reductionof 6- or 4-iodoglucosyl iodide by Bu.SnH is not accompaniedby this rearrangement.

HeTCH.CFTCH:CHCH: (E)

,zOAc

)"'n. -S* s2% o.o

A.o' {

\__/ / AcO OAc

3F,CH:CHCH2CH2C6H5 (E) r.cli:ations.3

ft'

In reactions with

)rrirnul vinyl radicalcan undergo Ir,r:'. .r C-H bond, which then

6OAc

Bu.SnH,

FO

o.o.( AcO

/

FO

\

\

onc

r)

AcO

f:'

t'-,*-*o.o..(

)

OAc

Y AcO

foo.

Allyl radical cyclization.s Allylic radicalsare lessreactivethan vinyl ones. but can undergocyclizationwith Bu,SnH/AIBN. ECrr Y I /

.//CHCHTBt,ornn,

Y \l

AIBN ----'

\-/

cH"oocncoocH,

rr,-""r:/\.j ".1

(E or Z)

cH3ooc coocH3

coocH3 5 9 : 3 1: 9

X '"1"X.",

f":"u cH,ooc\/\-/ cH3ooc

(cisltrans= 18:82)

CHrBr

z I)C.H5

cH3ooc coocH3

H ,CH:CH,

ay,

---------) | ) 86%| \.-.1--_1 .COOCH3 H /

cH3ooc ( 2 . 4 :l )

Tributyltin hydride

CH,BT

"o^l\

ov\.tH'y'" (-\,

;

Acyl radicals.t Tributyltin hrdndr eslen. r acylradicalsfrom phenylselenol or phenylthiolestersfor acyl radicalsfo

CH:CH,

(-,f.t-/ H (0/a= 5: 1)

B''

c

z^/4.

lt . i r l I ll anti-Radicalelimination.6 Reactionof nitroalkeneswith lithium benzenethiolate and then with aqueousformaldehydeprovides anti-1-phenylthio-B-nitro alcohols(1), which undergo radical elimination (Bu.SnH, AIBN, 110') to (E)allylic alcohols.

B-"r91I,^^ CHrTO' r)c6H,sLi lloo, -)C:Cf ,H AIBN, z)Hcno,CHr:rA.zOH -.,*CH'CH:CHNQT-.'* H-"-"-C'LOH | sc6H5 2 ( E l Z= 9 : r ) = 87:l3) | (antilstn RI --->RCN,1 One step required in a recent synthesisof 9,11-dehydrodigiexchange toxigenin(3) is an iodide/cyanideexchangewith the steroid 1. Direct yteld' 40Vo only ,.q,iir", protectionof the 14p-hydroxylgroup and proceedsin Bu.SnCl, by The exctrangecan be achievedby a free-radicalreaction initiated NaCNBH..and AIBN in82VoYield'

\./

-cos"c.tl

Z*coS€c6tL t t l

\A,S.-coocH.'

Acylation of isoquinolincs.t A mrr chlond at -78'with a 3-halopropionll quinolinesin 80-95Voyield (c/.. Li. ll with Bu,SnH/AIBN to furnish benzorr

o tl

+ CICCH.C}IJ

CN r-BuNC,NaBHTCN Bu,SnCl,AIBN 825.

Acylamino cyclization.t' Th€ ind by radicalcyclizatimt beensynthesized 2m acid,to providethe indolizidinones includedremovalof the keto groupbr c reagent(97%) followed by desulfunee

Tributyltin hydride

C H : CH, CH.,

.---1,,^) l

l

t'--,rf\.r'

329

Acyl radicals.s Tributyltin hydride in combinationwith AIBN can generare acylradicalsfrom phenylselenol esters,whichare a bettersourcethanacylchlorides or phenylthiolestersfor acyl radicalsfor intramolecularcyclization.

H ;r,r=5:1)

l l l o.:.icneswith lithium benzeneor :J cs anli-J-phenylthio-B-nitro t t s uS n H , A I B N , 1 1 0 ' )t o ( E ) -

\_/

I\aor.au",

H

,i:.,l,l;tfl_ - *E2% ' t

t t

Y)/ = (tro^tri? 62:38)

", cH,-..^ i'j ^./H -------------> u:u -'+ -c4on H/

4?cosecoH'

z>/\

\A-=-coocH3-(Af" cH2coocH3

2 (Elz = 99:r)

I . \ n r h e s i so f 9 , 1 l - d e h y d r o d i g i iii .teroid 1. Direct exchange rJ :.r\)ceedsin only 40Voyield. :i.i.tion initiatedby Bu.SnCl,

Acylation of isoquinolines.eA mixtureof an isoquinolineand Bu.SnH reacts at -78o with a 3-halopropionyl chloridein cH,cl, to give N-acyl-l,2-dihydroisoquinolinesin 80-95% yierd (c/., 13, l0). Thesecan undergoradical cycrization with Bu.SnH/AIBN to furnish benzoindolizidin-3_ones.

z\.'^\

\'\

CH. ,CN

R+ ll \r\zN

fr

B^::s:I'

.,4.

"''! | + CICCH.CH,I ' R* ll 8s-esqo \/\/,Y

/-\L4

L - l l l ) /'\,4< I on

/.r

|

|

o l5-8O%

BursnH,AIBN J

,, -ot \_/

Fo Acylamino cyclization.t, The indolizidinearkaloid( (3) has )-swainsonine beensynthesized by radicalcyclizationof the acylamineI, derivedfrom o-tartaric acid, to providethe indolizidinones 2 in Tlvo yield.conversionto the alkaloid(3) includedremovalof the keto group by conversionto the thiolactam by Lawesson,s reagent(97vo)followedby desulfurizationwith Raneynickel (96% yield).

Tributyllin hydride

(cHr)rSi\€r"rrJo. | | \-*{

*a"tt

OAc

)"'oe'c

BqSnH, AIBN c.H., A 't1%

'

'

Bo'Salt AIBN

SeC.H,

."OAc

)

O.,CHTCH:CHC6Hs I 2 ( - 1: l )

G" 3 p-glycosideshas relied heavily on the S-Glycosides.ttThe constructionof anomeric effect (equatorial cracetoxy substituent). A recent approach relies on generationof a radical at an alkoxy-substitutedanomericposition. The precursors (I). The samestrategycan be appliedto if; .un be obtainedas shownin equation p-linked disaccharides. constructionof

*-to'tt SeC.tl

(II)

ozCHzCH:cHc.4 4

1)Lrwessm'sregmt(62%) Bzlol

BZIOI

.ur4;,,fL-\ naoL t

BzlO

il'''#{:'i13?,n'"'*' , tt?e{\,*", \ ^-O

-

BzlO

i"r.

I nu,snn,elBr't --o'- | c.uPtt' loe |

Thioimidates can undergo similar rrl Deamination of RNH..B A new mctl amines(1.)involvesconversionto an at(f, verted to the hydrocarbonby Bu.SnH ro isfactoryin the deaminationof benzl'lamn of simplealkylamines.

.

ocH3 Bdo 2 (Plrr= 12:r) l with Bu$nH cyclization of selenoimiilates.D Reaction oi the selenoimidate (AIBN)generatesanimidoylradicalthatcyclizestothenitrile2andtheimine3 on nitrogenis changed of u.h.on,unone. Only 3 is oitained if the benzylsubstituent toanalkylgroup.Thereactionfollowsadiffer,:ntcoursewhenanN-tolylsele. noimidate (4) is the starting imine (equation I)'

l) cr! 2)socL

N,

r

R = CeHsCHz = CcHr:-c = CrHn-z

) C.H4:S

l

O I

Stereoselective radical cyclizltia Sridartahave noted transannularefiecrs< theseoctadienes(equationI). Thus rxlc spondingketone (3) is highly rraru-sckxt of the monosubstituteddiene 5. Cvclizat

Tributyltin hydride

331

*t""

SeCoH,

#

BursnH, AIBN

o..CHzCH:CHCbH5 2 (-l:l)

CN

,.CII.CH:CHc6H5 2 (s0%)

>ris has relied heavily on the tt , .-\ recentapproachrelieson tr,:Idnc position.The precursors I ..:nrcstrategycanbe appliedto

3 (50Vo)

CH, *'-TolYl

tl TD (rSECUH'

\Ao-cH,cH:GHC.H,

BzlO-r

^I J Z I^,l--\-----q U \ \ scH, Bz ro L \ \ urto 6c", I ABN ^-- | su.snH, o'to I c.tt.cx., lo'

l) c.Hpocl

BzlO--r

.^/rl--.-q IJZIU \ BzroL

Thioimidatescan undergosimilar radicalcyclization. Deaminationof RNH,.8 A new methodfor reductivedeaminationof primary amines(1) involvesconversionto an aromaticimidoyl chloride(2), which is converted to the hydrocarbonby Bu.SnH and AIBN (10, 412-413).Yields are satisfactoryin the deaminationof benzylamine,but are only moderatein the reaction of simplealkylamines.

RNH, 4!-.} \

o c H, \ \

BzlO 2 (Bls= 12.r)

l with BurSnH rhc.elenoimidate s :.' rhe nitrile2 and the imine3 ltr.lr!ueot on nitrogenis changed n: iourse when an N-tolvl sele-

1

R = cctLCHz = cF.nr-c - QH,,-z

C.Hr$:rVn

B'rsnH'AlBN,

RH

+ C6tIsCN

l

cl 2

G2%) 6lqd (3E%)

(Bz%) (ffi%) (37%)

Stereoselective radical cyclization ol 1,S-cyclooctadienes. Winkler and Sridarrahave noted transannulareffectson the stereochemistry of cyclizationof theseoctadienes(equationI). Thus radical cyclizationof crs-l and of the correspondingketone (3) is highly trans-selectiveand is more trans-selective than that of the monosubstituteddiene 5. Cyclizationof a 3,S-disubstituted cycloocteneis

Tributyltin hydride

2 (99:l trans) 2 (5: I trans)

cis-1 trans-l

A

o

p

.\"

8 D. L. Bogerand R. J. Mathvink.rDtd..fl.. e R. Yamaguchi,T. Hamasaki,and K. Udm r0J. M. Dener. D. J. Hart. and S. Ramesb.J " D. Kahne, D. Yang, J. J. Lim, R. Millcr. r '2M. D. Bachiand D. Denenmark . ibid..lll '3T. Wirth and C. Riichardt,Chimia.{1. ll0 'a J. D. Winkler and V. Sridar, TetrahedronL 1708(1986). 's M. D. Bachi and E. Bosch,J. Org.. {. l1t

Tributyltin hydride-Tributylphosplir r Reduction of carbonyl compl*.r duced to chlorohydrins by Bu.SnH in < HMPT.

V",tI \+

I I. Shibata,T. Suzuki,A. Baba. and H \llt

trans-4(95:5) Tributyltin hydride-Triethylborrnc. Deoxygenation of alcohols.r Dithr sponding alkane on treatment with BUS benzene.

(7:l) trans-6

5

S

can be correlatedwith The observedtrans-selectivity completelytrans-selective. rings' transannulareffectsin unsaturatedeight-membered acid derivativesof 4-phenylof thionocarbonic reaction The Thionolactones.B as the major product thionolactones provide (AIBN) can BurSnH with 3-butenol via a radicalcyclization.

tl

ROCSCH

Butyrolactones.2 The samereagent homopropargylicor homoallylicalcohob

S

fir r c6H5A.

nu,snH,,n*N BdJ^ c'H"A

./ocscH3 #

\ \-J l " + B u . S n S C H ,

lW. R. Dolbier,Jr., B. H. Al.Sader,S' F. Sellers,and H. Koroniak'Am, Soc.'103'2138 (1e81). t i, Morikawa, M. Uejima, and Y. Kobayashi,Chem' Letters,1407(1988)' 3 D. P. Curran,D. Kim, H. T. Liu, and W. Shen,Am' Soc',110'5900(1988)' a B. Giese,s. Gilges,K. S. Groninger,c. Lamberth,and T. vlitzel,Ann.,615 (1988);B. Gieseand K. S. Grdninget,Org. Syn.,submitted(1988)' r G. Storkand M. E. Reynolds,Am. \oc.,110,6911(1988)' 6 A. Kamimuraand N. Ono, t.C.S' Chem.Comm', 1278(1988)' 7 A. R. Daniewski,M. M. Kabat,M. Masnyk,J. wicha, w. wojciechowska,andH. Duddeck. l. Org.,53, 4855(1988).

c^H.scH" f :5

'li 'Ld

p't tnt""'tctJ'"' ; -Bu"SnscH' L

cr"r-,

fl scu"

c2H:\cE

( P'.-; a \-o

I

\-o

I K. Nozaki. K. Oshima,and K. Utimoto. Ic ' ldem, ibid.,29,6127(1988).

Triburyltin hydride-Triethylbonne

ED. L. Boger and R. J. Mathvink, ibid.,53,3377 (1,988). 'R. Yamaguchi,T. Hamasaki,and K. Utimoro, Chem.Letters,913(1988). r0J. M. Dener, D. J. Hart, and S. Ramesh,J. Org., 53,6022(1988). 'r D. Kahne,D. Yang,J. J. Lim, R. Miller, and E. Paguaga, Am. Soc.,ffO,8716 (1988). '' M. D. Bachiand D. Denenmark,ibid.,lll, 1886(1989). 'r T. Wirth and C. Riichardt, Chimia, 42,230 (1988). 'oJ. D. Winkler and V. Sidar, TetahedronLetters,29,6219(1988);Idem, Am. Soc.,l0E, 1708(1986). 15M. D. Bachiand E. Bosch,J. Org.,54, 1234(1989).

H I w t

o I

Tributyltin hydride-Tributylphosphine oxide. Reduction of carbonyl compounds.t ct-Chloro aldehydes or ketones are reduced to chlorohydrins by Bu3SnH in combination with I equiv. of Bu.PO or HMPT.

H

I I. Shibata,T. Suzuki,A. Baba,and H. Matsuda,,/.C.S. Chem.Comm.,882(1988).

i

l9<

Tributyltin hydride-Triethylborane. Deoxygenation of alcohols.r Dithiocarbonates are converted to the corresponding alkane on treatment with Bu.SnH (1 equiv.) and (C.H,).B (1 equiv.) in benzene.

H

I

S

.c:l\ltv can be correlatedwith d rrngs. nr .rcidderivativesof 4-phenylo.rctonesas the major product

BqsnH, ll (G'HJ'B, pg ROiSCH.

Butyrolactones.2 The same reagent effects cyclization of dithiocarbonates of homopropargylic or homoallylic alcohols to "y-butyrolactones.

S

LI

l-\/

O

,L_J

+ Bu,SnSCH,

Am. Soc.,l03,2138 H Koroniak, z::r'i. 1407(1988). t, . lr0,5900(1988). t 9.. I

E :e S 8 ) . andH. Duddeck, | \\., jciechowska,

,uE:'-ffilft|'*

fu"'

:ffi:

["'"') Bu,snH,(c,H,),R

I

'"

Cunr\,

2-'=,o

\\_o /

Ctnr-,

di*I K. Nozaki,K. Oshima,and K. Utimoto, Tetrahedron (1988). Letters,29,6125 ' ldem, ibid.,29, 6127(1988).

334

Tricarbonyl(triphenylphosphine)nickel

Tri-p-carbonylhexacarbonyldiiron,Fer(CO)n. Tricarbonyliron complexesof enones.r Reactionof Fez(CO)qwith c,B-enones in tolueneat 70-75'resultsin tricarbonylironcomplexes,which on reactionwith are convertedinto 1,4-diGrignard reagents,organolithium,oI organocuprates

Intramolccular el kynes.2 Ni(COD). ts ar (equationI).

ketones.

o iltt

r , , o o zBu ilgll'^Li 11 il F:(@L "-tln' ' cH,icucHrcnu C u H T C H : C H C B u - r r o c.H.-[-( nqa I O Fe(CO),

(r)

I CrHt

rT. N. Danks,D. Rakshit, J.C.S.Perkin/' 2091(1988)' andS. E. Thomas, Tri.p-carbonylnonacarbonyltetrarhodiumITetrarhodium dodecacarbonyl' 1 Rh4(CO)'rl.Preparation. Silytformylation of alkynes.2 p-silyl-c,p-enals can be prepared by reaction andcarbonmonoxidewith alkynescatalyzedby Rh4(CO)rr. of dimethylphenylsilane Yields are improvedif tiethylamine is alsopresent.Regioselectivityin the reaction with internal alkynesis controlledby stericfactors.

AcO

The intermediatec1r bonylation when CO phosphine)nickel is the r

l__ry-t. .oo' /

/

/

uI,

Rl\(Qo'

+C0+(CH)rC6HsSiH CHp=CH ry cH,

coocH,

coocH,

'C:CHSi(CH3)2C6H5

OHC' (ZlE = 80:20)

Br

(z) --+ co + R,SiH c6H5c=ccH,+

. -r;).:.(.:;

").:.
I W. F. Edgell,M. P. Dun\lc I W. Oppolzer, M. Bedora-

89:11

CH,'\"_c/ CIC=CCOOCH,+ CO + R,SiH 6'19o

OHC/

COOCH.

\si*, (2, lNVa)

rS. Martinengo,G. Giordano,andP. Chini,Inorg. Syn',20,209(1980)' ' I. Matsuda,A. Ogiso,S' Sato,and Y. Izumi,Am' Soc',11f' 2332(1989)' Tricarbonyl(triphenylphosphine)nickel, (CO)3Ni[P(C6HJJ (1)' Preparation't metal carbonyl is stable and less toxic than Ni(CO)4'

TrichloroisoplopoxfirNitro aldol reactiat Q primary nitroalkanesnltt selectiveif carriedout in t

g cH3(cHr)rNO2 (excess)

Trichloroisopropoxytitanium

on "i Fel(CO), with ct,P-enones Lp..;rer.which on reaction with ii.. .rr€ converted into 1,4-di-

Intramolecular allylationl methoxycarbonylation of alkenes ond alkynes.z Ni(COD), is an efficientcatalystfor intramolecularallylationof alkenes (equationI).

Sorc.4

o

nL:

$o,q4 so2c6H5

so2c6H5

o

ll

335

Ni(COD),.dDDb -t' 83%

(r)

ll

r-:1-- cH,iqHcurcnu CuHt

+ HOAc

AcO

r,.. ,: 1.3091(1988). lrarhodium dodecacarbonYlt

The intermediatecyclizedallylnickelspeciescan be trapped by methoxycarbonylation when CO and CH3OH are present and tricarbonyl(triphenylphosphine)nickel is the catalyst.

rl. ,.rn be preParedbY reaction bYRho(CO)". !.\\ nescatalyzed in the reaction Rcgioselectivity

;_ry-Tt

t)

i / cH,

^,/Tt 'or';y"o'>a .o, ",

*-tt

+ CHTOOC

8n, floo", -coocH3

o (4:1),47Vo

Rh.(co),1'

297o

\ C.H.),C^H., 100' ',rll_---

coocH3 coocH3 ,i.C.H.

Br to"'ta:

cll

* R.sil

\:K

Q)

,""t \cHo

891 : l ,COOCH3 'siRr !

''-r )

r r

2tt lt)9 (1980). lll.1332(1989).

' W. F. Edgell,M. P.Dunkle,Inorg.Chem.,4,1629(1965). ' W. Oppolzer, (1988). M. Bedoya-Zurita, andC. Y. Switzer,Tetrahedron Letters,6433 Tiichloroisopropoxytitanium,Cl.TiO-i-Pr (1). Nitro aldol reaction (Henry reactiont). The reaction of the anion (BuLi) of primary nitroalkaneswith aromatic aldehydesto form p-nitro alcoholsis antiselectiveif carriedout in the presenceof this titanium reagent(1 equiv.).' OH I

cH3(cHr)NO,% This P r( tl.),1 (1). Preparation.' O

(excess)

ICHTCU'CH:NO,LiI"#

c.H,\aC'H' : NO, ( 7 :l )

336

Triethylammonium bis(crtecholrto)alkenylsiliconates

'H. B. Hassand E. F. Riley, Chem.Revs.,32,406(1943). 2 A. G. M. Barrett, C. Robyr, and C. D. Spilling,l. Org,,54, 1233(1989).

1,1,1-Trichloro-3 r3,3-trifl uoroacetone. Dehydration.r Primary and secondary alcohols undergo dehydration when refluxed in benzene with CF.COCCI. and a trace of p-toluenesulfonic acid.

The pentacoordinateorganosilicu yltrialkoxysilanes with catecholal Coupling x'ith halidcs ot J a catalysts,thesereagentscoupleri erate to high yield. i

p-CH,OC.H.CH2CH2OH

p-O'NC.H.I + lr rr*+ f-CHTOC.HICH:CHt

*+*-O cH3cH(cHr)5cH3'l

57o

OH

C.HTCH:CHBr +

rA. Hosomi,S. Kohra, andy. Toauc

cH3cH:cH(cH)4cH3 (E)

T[iethylborane. Radical addition of RTSIII r for initiation of this radical reactrq is sluggishin the absenceof ox1'gc

1S. Abdel-Baky 1795(1988). andA. Moussa, Syn.Comm.,18, Triethylamine. Seleno-Pummercrreanangement. Diacetonylseleniumdichlorides (1) when treatedwith triethylaminerearrangeto o-chloroselenides(2).'

o

o

rcn:)'c:ro (cH')'Hc[ g! 2cqcoc(cHJ, Yc(cH')'#- to \r.Aa,ftnt"""' \r"/ -cl

cr/

RC:CH + (CuE)rSnH€

.,

n-CrH,,C=CC'H,,-n+ (qfUS

Triethylboranecan also iniriarc vinylstannanes.

I

oAcH

I J. Nakayama and Y. Sugihara, Chem. Letters,l3l7

(1988).

rqr\j arq t

'"'#t."

(1). Triethylammonium bis(catecholato)alkenylsiliconates 'K. Nozaki,K. Oshima, andK. Udm

la,R=H b, R = CeHs

Triethyloxonium tetrafluotobo"&. a-Amino esterc.r These comp conversionto lactim ethers(2) nith are hydrolyzedby water to the sals

Triethyloxonium tetr&fluorobor&te I

. sr 1r33(1989).

l) undergodehydrationwhen acid. | ;--:oluenesulfonic

337

The pentacoordinate organosiliconcompoundsare obtainedby reactionof alkenyltrialkoxysilanes with catecholand N(CrHr)r. coupling with halides and triflates.r In the presenceof several palladium catalysts,thesereagentscouplewith vinyl or aryl iodidesand aryl triflatesin moderate to high yield. Pdct(qHrcN)!

p-OrNCuH.l 1 11 ---dm------+

C.H.CH:CH,

C.HTCH:CHBr

+ lb --+

p-OTNC.H.CH:CH,

C6H5CH:CHCH:CHC.Hs

I A. Hosomi,S. Kohra, and y. Tominaga,Chem.pharm. Bull.,X,4622 (lggg\. r C l { .r . C H , Tliethylborane. Radical addition of \SnH to -i=C-.r B(C2H,). is as efficient as AIBN for initiation of this radical reaction resulting in vinyltins selectively. The reaction is sluggish in the absence of oxygen.

s
RC:6H

+ (CuHr)rSnH

B(qH'),,25'>\c:c/ -\ + (Z)-isomer 1s-8s% ./ 'Sn(CoHr),80:20 H' (E)

o o l l l l

,cH,)rHCC ,+

CCH(CH3)'

lt

n-CrH,,.

l l

-s"^cl 7

H/

e sr l )

il

,Sn(CoHr)3

\crH,,-n

Triethylboranecan also initiate radical cyclizationof unsaturatedalkynesto vinylstannanes. OACH

F

' c:c'

n-c5HilC=CqH,,-n + (c.Hr)rSnH--r

"",4

|

"

cH,AcH, I K. Nozaki,K. Oshima,andK.

(c_6H,)!snH,

nloil't, %

Pf ,Sn(c.H,), cH,"'\rX [",ar,,,

Utimoto,Tetrahedron,45,g23 (1ggg\.

Triethyloxonium tetrafluoroborate. a-Amino esters.t rhese compoundscan be preparedfrom lactams(l) by conversionto lactim ethers(2) with (crH.).o*BF4- to providethe salts(3), which are hydrolyzedby water to the salts(4) of co-aminoesters.

Ttifluoroacetic scid

(Cf!)n /

ttlJ"l

(qH,Lo'Bn cHcr"

\

\;z-oc,u,

\AO N H

llo -=+

(cHt-coocrH, (*,u*-

ii BF.-

1,n=l

2

987o 80%

CIt . I -r RrtSicHcH:NC(CHr),+ RcHo I

877o 907o

rR. Menezes andM. B. Smith,Syn.Comm.,lE,1625(1988). Tliethylsilane-Titaniurn(IV) chloride. Reduction of bicyclic ketsls.r Reductive cleavageof the bicyclic ketal I in the presenceof a Lewis acid favorscls-products,regardlessof the reductant.The is obtainedwith (crH5).SiHand Ticl4. DIBAL showshigh highestcls-selectivity 'R. Desmond,S. G. Mills, R. P. Volanrc. r

|

( 1e88).

ctr'cr'>

|

H-l l-n Hoi\o/tH),oBzl

"{ot(CH,),oBzl

+ffans-2

cis-2

I -78" Ticl4/(c2H5)3siH' DIBAL, OO

rN% 1007o

99.93:0.07 4:96

This reactionprovidesone stepin the conversionof l-malic acid rrans-selectivity. into the opticallyactiveform of a civet cat acid (3).

Ttifluoromethanesulfonicacid, CF.SO.ll. Protonation otnitroalkenes. This su nitroethylene,to give N,N-dihydro4rmir arenesto give arylated oximes.This orr methyl ketonesfrom 2-nitropropene., H cFfq'

(c,H:].!siH, ^ t

l

H+-^z].(cHr)roBzl , " O

-t*t

,.\.,*o, I

CH,

)

["k

(1988)' rH. Kotsuki, Y. Ushio,I. Kadota,andM. Ochi'Chem.Letters,927

I K. Okabe,T. Ohwada. T. Ohta.andK. Shc

Trifluoroacetic acid. (El-o.-Methyl-arp-enals.t The anion of the t-butyl- or cyclohexylimineof o(1) is known (13, 323)to reactwith aldehydesto pro' trialkylsilylpropionaldehyde asa mixtureof (E)- and (Z)-isomersin the ratio 1.3-11: 1. vide cr-methyl-a,p-enals rnfermediatesisomerizemainly to the (E)'kOmerS when imine Flowever,the crude treated at room temperaturewith ttifluoroacetic acid.

Trifluoromethanesulfonicanhydridc (l l. Ritter reaction. The original versto to an amideinvolveda reactionwith niml version,the alcoholis convertedinto a tri treated with a nitrile (2 equiv.) in CH,CI, r yieldsare 50-98Vo.The advantageof thb and secondaryalcoholsas well as tertiaq'

Ttifl uorornethanesulfonic anhydride

cHr-cooc,H5

(fr",".,

rcc'Buli ' l-*"":.1"8 *,'r,lXt":Nc(cHJ3 +RCHo I -cH:N-ctcn'lJ t L I r)cr,cmx,zo'

L\

| 2) t{,o

"-lsc .f the bicyclicketal 1 in of the reductant.The ar.i,ess xJ TrCl,. DIBAL showshigh

a"o

R^crt GE> rm:i) ' R. Desmond, S. G. Mills,R. P. Volante,and I. Shinkai Letters,2g,3895 , Tetahedron (1988).

+ tans-2 .H ''CH:)2OBzl r. 9.93:0.07 4:96

Tlifluoromethanesulfonicacid, CF3SO,H. Prctonation of nitroalkenes. This strongacid diprotonatesnitroalkenes,even nitroethylene,to give N,N-dihydroxyiminiumcarbeniumions, which react with arenesto give arylated oximes.This overall processprovidesa route to o-aryl methyl ketonesfrom 2-nitropropene.r

hc .()nversionof l-malic acid

|

H "\*o,

------+

cH,

l{.,.OBzl

.pp;.""" (-)-3

f-H oH H cFso'H, lL..",\,o'-o" l"\(oH L

CH,

CH,

I l I

"n tto J

o tl

c6HJcHrccH3

z : : ,' . . e 1 7( 1 9 8 8 ) .

I K. Okabe,T. Ohwada, T. Ohta,andK. Shudo, J. Org.,54,733(1989).

of curr.- or cyclohexylimine to Pro ) rc.tclwith aldehYdes , r \ \ m c r si n t h er a t i o1 . 3 - 1 1 l:. when arr,r to the (E)-isomers d

Trifluoromethanesulfonicanhydride (L). Ritter resction. The original version for this conversionof a tertiary alcohol to an amideinvolveda reactionwith nitrilesin a stronglyacidicmedium.rIn a new version,the alcoholis convertedinto a triflate, which neednot be isolated,but is treatedwith a nitrile (2 equiv.)in CHrCl, and then with aqueousNaHCOr. Overall yieldsare 50-98Vo.The advantageof this versionis that it is applicableto primary and secondaryalcoholsas well as tertiary ones.2

340

Trifluoromethyl bromide

l

RoH+

lnorr L

*tn '

-

tui:cR'orf

t -W* J

| s0-e8%RNHC9R'

' L. I. KrimenandD. J. Cota,Org.React.,17,2l3(1969). ' A. G. Martinez,R. M. Alvarez,E. T. Vilar,A. G. Fraile,M. Hanack.andL. R. Subramanian,Tetrahedron Letters,m, 581(1989). N-p-Trifluoromethylbenzylcinchoninumbromide, 12, 379 -38I ; 13, 325. Asymmetric synthesisof a-amino acids.l This optically active phase-transfer catalyst (1) can effect enantioselectivealkylation of the imine (2) derived from glycine.The highestenantioselectivity obtainswith the t-butyl ester; the lowest with benzylic type esters.Alkylation of 2 resultsin a mixture of enantiomers,but crystallizationof the mixture removesthe racemicproduct and leavesthe highly pure opticallyactiveamino esterin solution. p4lC.H,CHrBr, 1

I

(CuH,)rC:N COOC(CH3)3 + gl, tt

cHrcuHncl-p (R)-3

ry

: l.t( : Hrg

n

o

'I. Ruppert, K. Schlich, and W. \blhar-h. ? G. K. S. Prakash,R. Krishnamunr. and

-_ cooc(cH3)3 CHrCuHnCl-p

(s)-3

rM. J. O'Donnell,W. D. Bennett,and S. Wu, Am. \oc.,111' 2353(1989).

Triffuoromethylbromide. by CF3Bron of arenes.tArenesaretrifluoromethylated Trifluoromethylation reactionwith uracil irradiaiion(315-440nm) in acetonitrile.This photochemical in 11% yield' provides5-trifluoromethyluracil

(78Vo)

'-F--

Trirnethoxysilane-Ditithium 2.$trr S,N-Acetals. Reductionof alkrlr 0o resultsin S,N-acetals(2) as rhe mt LiAlH4 or NaBHoresultsin tenian aE tertiary amine.r

t%HL (C.H')rC:NCHTCOOC(CH3I, ) (CuHr)rC:N-*

Tlifluoromethyltrimethybilene, (CH, |J ClSi(CH3).,and hexaethylphosphon Trifluoromethylation of carbryI , reagentaddsto a carbonylgroup ro g trifluoromethylatedalcoholin 6o-9lc

(22Vo)

rT. Akiyama, K. Kato, M. Kajitani, Y. Sakaguchi,J. Nakamura, H' Hayashi, and A Sugimoii,Bull. Chem Soc.1apan,61,3531(1988)'

p-CH,OCuH.C:tf

I \ J scrltt-

9 -

I Y. Tominaga,Y. Matsuoka.H. Havashd 29, s771(1988).

Trimethyhluminum. Cleavage o/ (2S,3S)-3-pica-v[l.r

number of nucleophilesregioselecrN The cleavageusuallyoccurswith dm (>99 : 1). Trimethylaluminum.horet Triethylaluminumreactswith I to gr

Trimethylaluminum

I

ttto', I ' -uton RNHCoR' J fr, andL. R. Subrararlc.\1. Hanack,

ll. .r79-381;13,325. i: opticallyactivephase-transfer of the imine (2) derived from ith the l-butYl ester; the lowest ,n .r mixtureof enantiomers,but r nroductand leavesthe highlY

341

(CH)rSiCF, (1). The reagentis preparedfrom BrCF3, Tiifluoromethyltrimethylsilane, ClSi(CH3),,and hexaethylphosphoric triamidein 65-70% yield.l Trifluoromethylation of carbonyl compounds.2 In the presenceof BuoNF,this reagentaddsto a carbonylgroupto give a silyl ether that is hydrolyzedto the free trifluoromethylatedalcoholin 60-92Voyield.

A

ltl'B:":T*"&.,, o

OH

' I. Ruppert,K. Schlich, (1984). andW. Volbach,Tetrahedron Letters.25,2195 ' G. K. S. Prakash, (1989) R. Krishnamurti, andG. A. Olah,Am. 9oc.,111,393 Trimethoxysilane-Dilithium (CH3O).SiH-[LiOCH(CH3)]',(1). 2,3-butanediolate S,N-Acetals. Reductionof alkylthiomethyleniminium saltswith I in THF at 0" resultsin S,N-acetals(2) as the major product. Reductionof thesesaltswith LiAlH4 or NaBHaresultsin tertiaryaminesor a mixtureof 2 and the corresponding tertiary amine.r

I )l1

.iC:N-

-COOC(CH3)3

: cHrCuHnCl-p (s)-3

p-CH,oCuHoC:\Jo

#

p-CH,oC,HoC\_Jo

sc2H5l-

sc2H5 't

x

1 1 1 . 2 3 5( 1 39 8 9 ) '

bY CFrBron I rnfluoromethYlated reactionwith uracil K\r\rchemical

,r -zx w A Z* ' (22Vo) J \akamura, H. Hayashi,and A.

I Y. Tominaga, Y. Matsuoka, H. Hayashida, Letters, S. Kohra,andA. Hosomi ,Tetrahedron 2 9 , 5 7 7(11 9 8 8 ) . Trimethylaluminum. (l).1 This epoxide(1) is cleavedby a Cleavageof (2S,3Sl-3-phenylglycidol number of nucleophilesregioselectively at the benzyliccarbon to give 1,2-diols. The cleavageusuallyoccurswith almostcompleteinversionat the benzyliccenter (>99:1). Trimethylaluminum, however,reactswith retention(32:1, equationI). Triethylaluminumreactswith I to give the correspondingadductsin a 1:1 ratio.

"..9",

cuH'a-on

o" rr],

34

Trimethylsilylazide

rS. Takano,M. Yanase,and K. Ogasawara, (1989)' Heterocycles,29,249

-

r,sdt

-

t--'"+

Trimethylgermanium halides, (CHq),GeBr(Ct) (1). y-Reactivity of germanium dienolates of a,p-unsaturated esterc.t The germanium dienolate 2, obtained by reaction of the lithium dienolate of the enoate

cH.,co,cHr.,

with 1.,reacts with electrophiles at the 1-position. r)LDA'rHF cHr--_ ')C-CH ___aGe(CH.r)3 '" > -^'-cooc,H, (CH3)2C:CHCOOC2H5

cH1'

,_

Y=r

Primary amines.2 (CH,).Si)i. in rb with (CH,),SiOCH3+ HN.. This in srru to converttrialkylboranesinto primary |

,

oCH,

I -t ric! Jr -_) c6H5cHCHzf:CHCOOC,H' 2 + C.HTCH(OCH'), r"

RrB + (CHr)rSiNr+CH,OH <

CH, (Elz= 9.5:r) I Y. Yamamoto, (1988)' Chem.Comm.,1639 andJ. Yamada,l.C.S. S. Hatsuya,

Example: l) B4.Ttf ll 2)(cr|'r'$fc

.zA.r I

Trimethyl orthoformate,HC( OCH.)3. Benzylidenes. Thesederivativesof sugarsare generallypreparedby reaction with benzaldehydecatalyzedby an acid (generallyTsOH). But a large excessof the aldehydeis generallyrequired.One expedientis useof trimethyl orthoformate to removethe water generatedduring acetalization.l

cHpH. Ho v.cooH ,oJoot"' C.H,{ + HC(OCH,), + C.H,CHO I # J o- t"ooc", Hol"'cooH

t

,

,

IM. Emziane,P. Lhoste,and D. Sinou.Sr"u ' G. W Kabalka,N. M. Goudqaon.and Y L

Trimethylsilylmethylmagnesium I -Trimethylsilylbutadienes.r

dlqi& Ttresc Grignard reagent (f) with allylic dirhror

c.H,--as)

.tl&.

ts/

' H.-S.ByunandR. Bittman,Org. Syn.,submitted (1989).

cH,\^{t--1 Trimethylsilyl azide. AZidohydrins.l Epoxidesare convertedto tr4ns-siloxyazidesby reactionwith N3Si(CH3)r(1.5 equiv.) and aluminum isopropoxide(1 equiv.) in CH'CI'. Thc reaction involves selective attack of azide on the less-substitutedcarbon of the epoxide.

er

-

\-/

' CuHt

ts/

e:.l

_

.|
r Z . - J . N i a n dT . - Y .L u h , , / . O r g . . l l . 5 S A t l

chloride Trimethylsilylmethylmagnesium Nrs(cH!)l /,'\,OSi(CHJ3 A(o-t-P!),)l ,I . . . N , ,14% _

:re (1989)

t

O

cH'co'cH"''

sturated esters.r The gerium dienolateof the enoate

o

a'

cH3co2crLCHCrLN3

6r,1.",v,

in the presenceof methanolis in equilibrium Primary amines.2 (CH3)3SiN3 in situ generationof hydrazoicacid can be used This + with (cH3)3SiocH3 HN3. amines. primary into to converttrialkylboranes

- L-,,rGe(cH)t rr-

-cooc'Ht

l

l. ll{.C:CHCOOCzHs .I

RrB + (CHr)rSiN,+CHrOH-+

N2

CH, L 7 ,= 9 . 5 : l )

Example: ( , ' r n i . . 1 6 3 9( 1 9 8 8 ) .

cncrallvpreParedbY reaction f.()tl). But a largeexcessof u.t' Lrftrimethylorthoformate

-

^coocH3

. P-/ + c^H.< | '

-

I M. Emziane, (1988)' andD' Sinou,Synthesis,54l P.Lhoste, ' G. W. Kabalka, andY' Liang,Syn.Comm',lE,1363(1988)' N. M. Goudgaon, Tiimethylsilylmethylmagnesiumchloride (l'). l-Trimethytsilylbutadienes.rThesedienescanbe obtainedby reactionof this Grignardreagent(1) with allylic dithioacetalscatalyzedby Cl,Ni[P(CuH,)J,'

t"')'.

v

coocH3

coH, 4s

-t] tr/

",[i'[l]r,, C uH, :/Msi(cH3)3 et%

)r

.", s-.rloxyazidesby reactionwith dc rl equiv.)in CHzCL.The lc..-substitutedcarbon of the

)a7^..t1t ts/I 1.",

c,H,-,(vs(cH3)3 - 88q

cH, EIZ = 94:6

' Z.-J. Ni andT.-Y. Lrlh, J. Org.,53, 5582(1988)

p-(Trinrethylsilyl)ethoxymethylchloride

M

(2-frbd

Trimethylsilyldiazomethane. Silylcyclopropanes.r Photochemical or metal-catalyzedreactions of (CH3)3SiCHN, with aliphaticalkenesresultin silylcyclopropanes. CuH,

t t l t t l \NAB, 1

PdcL

\-.

,y''\..oCH"oC4CIr:Si (clt!

+ (CELSiCHN,-&g-+

cooc,H, I CuHr_

CuHr_

pcooc,n,

Scooc,H, * (cH3)3si/\H

H^silcHr;, (45vo)

(34Vo) c6H5\

CuH5

/cocH3

--f + (CHr)rSiCHN,

(_\

COCH, )

H 3

In the absenceof a catalyst,the reagentcan undergoa 1,3-dipolaradditionto furnish a pyrazole,as in the caseof (E)-benzylideneacetone (2). (El-l-Trimethylsilyl-I-alkenes.z These alkenescan be prepared by reaction of the lithium anion (1) of trimethylsilyldiazomethane with primary alkyl halides followed by decompositionwith CuCl (86-96Voyield). (E)-2-Aryl-1-trimethylsilylethylenesare obtaineddirectly by reactionof trimethylsilyldiazomethane with benzylsulfonyl chloridesand triethylamine.

t""""'l'*',CH3(CH2)tCH2xrr,a"rr' cH3(cHJsCH2" I J

cucl,crHe, A

CH3(CHr)rCH: CHSi(CH:): (E/Z = 95:5) I T. Aoyama,Y. Iwamoto,S. Nishigaki,and T. Shioiri,Chem.Pharm.Bull. 37,253 (1989). ' T. Aoyama and T. Shioiri, Tetrahedron Letters,29,6295(1988).

p-(Trimethylsilyl)ethoxymethyl chloride, 10, 431. SEM ethers.t The synthesis of orelline (4), a2,2-bipyridine derivative, from the SEM ether (1) of 2-bromo-3-hydroxypyridine involves metal-halogen exchange

3

l-''

. o l

followed by couplingto pror-iderh groups,2 is lithiatedat the {.J'-posi stepsto the toadstooltoxin 4.

' H.-A. Hasseberg andH. Gerlach.ffcl

(2-Tiimethylsilylethylidene)trb( 2.(2-CHrC6H4)3P:CHCH:Si(CH, f, ( I (Z)-Allyltrimethylsilancs.t R( lidinetriphenylphosphorane has be thylsilanesas a mixture of (E )- and ylphosphineby tris(2-meth.'-lpbenr ; in reactionswith aliphaticsaturald into the (Z)-allylsilanes(Z E > 9 generationof the phosphorane.

(2-fi merhylsilylethylidene)tris(2-nethylphenyl)phosphorane

ocrLcrlsi(cH,)3 r!-;.rtllvzedreactions ol )Fr()paneS.

Tl.ocn

\*Ar.

',ro"f rn,*,",',r,.,"p,

I

C ^ H-. -

v

'

1 BuLi,_50.

-cooc,E

\-^

l-

si(cH3)3

H

(459o)

. /cocH3 , \ \

t,\ ll

r*n, f."u"r"t

-l

rg,- .t 1.3-diPolaradditionto r c t , r n e( 2 ) . c.1nhe PreParedbY reaction K \\rth primarYalkYl halides ld r r E)-2-ArYl-1-trimethYlsiwith ncrhr Isilyldiazomethane

rrCt{,t. f . , H , , l

tt. ,.CH:CHSi(CH3)3 t ' - Z= 9 5 : 5 ) yn'. ['lnrm. Bull. 37,253 (1989). l

!\\

)

l.i -i.rpvridinederivative,from oir c. metal-halogenexchange

2' Thanksto the SEM followed by couplingto provide the bipyridinederivative is convertedin several which 3' provide groups,Z ls Utf,iateaat the 4,4'-positionto stepsto the toadstooltoxin 4. I H.-A. Hasseberg Helv',71'957(1988)' andH. Gerlach,

(1)' (2-CH,C6H4).P:CHCHzSi(CH,). ' (z)-Aliyltrimethylsilanes.t Reactionof aldehydeswith 2-trimethylsilylethyhas been used to convert aldehydesinto allyltrimelidinetriphenylphosphorane thylsilanesasamixtureof(E)-and(Z)-isomers(9'492)'Replacementoftriphenenhances(Z)-selectivity'particularly ylihosphine by tris(2-methyiphenyt)ptrosphine can be converted in reactionswith aliphatic,utu.ui.J aldehydes.Thesealdehydes BuLi at 0o for of use with and 1, s (ZlE > 94Vo)with into the (Z)-allylsilane of the PhosPhorane. generation

'345

Trimethylsilyl trifuoromethanesulfonste

t H. Iio, M. Ishii,M. Tsukamoto, (1988). Letters,29,5965 Tetrahedron andT. Tokoroyama, (CHr)rSiNCSe,b.p' 75-76'130mm. The reagent Trimethylsilylisoselenocyanate, with KSeCNin CH3CNor DME at 25' (80of ClSi(CH)3 is preparedby reaction 90Vo yield). O-Trimethylsilyl cyanohydrins.t Substantiallyno reactionoccursbetweenaldehydesor ketoneswith I in the absenceof a catalyst.In the presenceof znCl2, aldehydesreact with 1 in cyclohexaneto give o-trimethylsilyl cyanohydrinsand elementalseleniumin high yields.The mainadvantageof thisreagentover (CH.)rSiCN Thus it reactsselectivelywith an aldehydein the presence is the chemoselectivity. of a ketoneor in the presenceof an aryl aldehyde.However,there is only slight selectivitybetweena primary and a secondaryaldehyde.Sincethe reagentis sensitiveto moistureand air, a one-potreactionwith an aldehydeis usuallydesirable. ' K . S u k a t al ., O r g . , 5 4 , 2 0 1( 159 8 9 ) .

cl,Pd(c6H5cN)r.

"#5/ o

( \J

(cH-)-sicrrf

k9:1' -ocH, :* '( \-/ /hoc e4ro

O<")--;;-ocH,clt!

2-Trimethylsilyloxy-l,3-butadiene. I2'+2lPhotocyclization.t The dieneI undergoes[2+2]photocyclizationto 2that canundergoPd(II)-mediated to givebicyclicvinylcyclobutanols cycloalkenones when treated with ring expansionto bicyclic c-methylenecyclopentanones

l-n-CHz

acetalswith (CH.).SiOTf(1.1-1.7equrr ) pylethylaminein CHrCluat -20 to 2-i'. Dho by this methodto enol ethers,but lonser r

fooc,H5

.cH" ' ' *rr.Aor,

crH'ooc-1

...osi(cHJ! n '"""-f--T-l-cH:*L ur-

ffi'n

e6% \.,/

This reactioncanbe usedasthe fint step stepsare cyclopropanation and photochem (.1.{'-DC presenceof 4,4'-dicyanobiphenyl

(cH,), :ffi

l

A),^,

--_-)ll

9CH,

o

I

(cis,12:l)

,nf",,*"."fnt cJrsooq--1l/""

H#ft" d

H

' M. Demuth, B. Pandey,B. Wietfeld, H. Said, and J. Viader, Helv.,7l, 1392(1988)'

Trimethylsilyl trifl uoromethanesulfonale. Acetals--+vinyl ethen. The classicalmethodfor this transformationis thermal eliminationof an alcohol substituent.A new method' is the reactionof dialkyl

t

crlr?

\

TdCt

(c4\

(CH,)" l n = 3 =5 =6

l4Vo 78% 607o

Cyclopentanones.aThe adducts2. ol followedbr tre lithium with cyclohexenone give can rise to oclohc with a Lewis acid products.r give mixtures of both tendsto Thus mationof cyclopentanones. the addu only the cyclopentanone6. Reactionof I 5 9: 4 1 .

Trimethylsilyl

5965(1988). dnn Letters,29, --h' 30 mm. The reagent { ( \ or DME at 25'(80eJcllonoccursbetweenalof ZnCl2, In the presence and thrlrilvl cyanohydrins (CH,)3SiCN over rcaqent r\ r .rl.iehydein the presence rcrcr. thereis only slight . 5rncethe reagentis senehrdeis usuallydesirable.

to 2| - I lphotocyclization n unJergoPd(II)-mediated o n g . w h € n t r e a t e dw i t h

acetalswith (CH3).SiOTf(1.1-1.7 equiv.) and an equivalentamountof diisopropylethylaminein CHrCl, at -20 to 25'. Dioxanesand dioxolanesare alsoconverted by this methodto enol ethers,but longerreactionperiodsare necessary.2

G:r: #$o.n, -'*-

O<":)

"/i t

Uo"ocH'osi(cH3)3 ocH,cH,osi(cH3)3

ocHrcHrosi(cH3)3

cH'

l

-- /Yc^' (,

AlcH'

,,1,,(/

of acetals;remaining This reactioncanbe usedasthefirststepin a ring-expansion cleavageof the cyclopropanein the and photochemical stepsare cyclopropanation (4,4'-DCBi,2) as sensitizer.l presence of 4,4'-dicyanobiphenyl

ctll ZnlC!

->

( c i s ,1 2 : 1 )

,r*f.u*c"r,u ln=3 = 5 =6

c.H.ooc CHr._/

(

(

)(cHr)"

) (cHrL_,

457o 317o 3l7o

o

CH;

6

l4Vo 78Vo ffi%o

'"'X, #d,='"'2<'"'

H

r. H,'1t..71,1392(1988).

is thermal Lsrr.rnsformation I r: (he reactionof dialkYl

Cyclopentanones.aThe adducts2, obtainedby reactionof trimethylstannylfollowedby trappingwith an electrophile,whentreated lithium with cyclohexenone TiClr and/or cyclopentanones. with a Lewis acid can give rise to cyclohexanones tendsto give mixturesof both products,whereastrimethylsilyltriflate favorsforThusthe adduct5 on treatmentwith TMSOTf provides mationof cyclopentanones. only the cyclopentanone6. Reactionof 5 with TiCL gives6 and 7 in the ratio 59:41.

Ttimethylsilyl trifl uorcmethrnesulfonate

o

.\ t

\in'

o

o

ll

*!9rr,'"'' 2 ) R ' x' I&-, p * '

TMSCnf ,

-R'

.\,cHzR' +

\_J

2

?r'*,

-orf

\__n{i,a.",,,

o

tl

V-sn1cH.;,

t

,\ 3

,,A7

.-

-.qr

Id

4

[c'H'l

R, H +4

Aldol reaction.6 This tnflate rsi betweensilyl enol ethersand acctd regardless of tbc high syn-selectivity

Rt

osiR3

Example:

C.u$t

o

o ,\

cn

l) (CHr)rSnLi 2) H.O --j--+

f l

l l l

cHa'J

tl -Ar

TMsorf -?8' 52qa

I l

?SiR, curo\'-cH3+

Sn(cH),

cH;"\

s

o

o tl

tl

-A. -CH, \ / \ J + CH;.. 6 (translcis= 23:l)

t 7

of enones p-Alkytation of enones.s The products(1) of phosphoniosilylation in THF at -7X presence of TMSOTf (14,60)react with activatedalkenesin the p-alkylated products. to give

TBDMSOTf P(C.H.)",THF

_OTf + P (C6H5)3

Acetals of hexopyronosidcs-' I 2 can be preparedbr n copyranoside 3') in the presenceof this triflate.

f"'

-rrr:$

+ C:O

I ocH3

clt:G@,C,H,, 58% ovqsll

c6FLcH

l

cn;"\,/ 100:I

+ C.H.CHT I CH,

2, R, = Si14tt616grrt

cHrcH2co2c24

I P. G. Gassmanand S. J. Burns.,/ ! I d e m ,i b i d . , 5 5 , 5 5 7 6 (1988).

Trimethylsilyl trifl uoromethanesulfonate

o E t ,

o l

-orf

a\ t

^

a\cHzR' +

\__lt-

3

c_C,H,,CHO ,

i1c.H,;,

\J-R

l- ?siR3

4

L \ l \

I

I

?

1 ".".,A I'ii!"\ //

-cHCuH,,_. | "::n

I yt"c.H,,_c

osi(cH3),-orl [c6H5)3p-

t"

Aldol rcaction.6 This triflate is an effectivecatalystfor an aldol-typereaction betweensilyl enol ethersand acetalsat -78". The reactionshowsmoderateto regardlessof the geometryof the enol ether. high syn-selectivity

''

?siR3

c,H^

?

?tn'

c.HlfcuH,

+ cuH,cH(oc",l, %4 CH,

craoni?t,zg)

B rl'

o tl

o CH,

cu;"\-/ 100:1

6

7

of enones ph,'.phoniosilylation .IMSOTf in THF at -7tr e ,,r

q

OSiR. t cH,o\,/cH3

l + c6H5cH(ocH,L-;;*

,.

,,t\

4

l l -Y\cHrcH2co2c2Hr

QCH, :

cHro^-c.H, CH, = 55:45) (sYntanti

The pyruvic acid acetal(3) of the methyl gluAcetalsof hexopyranosides.T prepared by reactionwith ethyl pyruvatein CHrCI' ( - 5 2 can be copyranoside 3') in the presenceof this triflate.

CH"

/osiR3 \

I

+C : O

R,siovo\ o tl

t

B,ro>aD

l. crlcl 3l%

coocrH5

ocH3 2, R.= Sil4tr61611,r, r P . G . G a s s m aann dS . J . B u r n s J, . O r g . , 5 3 , 5 5 7 4 (1988) ) Idem,ibid,,55, 5576(1988).

3, (R/S)= 31:24

350

ylides Triphenylnrsonium

r L. Friedmanand H. Schecter,ibid.,26,2522 (1961). aT. Sato,T. Watanabe, T. Hayata,and T. Tsukui,J.C.S.Chem.Comm.,153(1989). s S. Kim and P. H. Lee, TetahedronLetters,29,5413(1988). 6 S. Murata, M. Suzuki,and R. Noyori, Tetrahedron,44,4259 (1988). 7 H. Hashimoto,K. Hiruma, and J. Tamura,CarbohydrateRes.,177,C9 (1988).

(Trimethylstannyl)copper

reagents. Additions to arp-acetylenic esters. Piers e/ al.l have prepared a number of these reagents, and conclude that (trimethylstannyl)copper(I)'dimethyl sulfide' (CH3).SnCu'S(CH3), (1), is the best reagent of this type for conversion of l-alkynes to 2-trimethylstannyl-1-alkenes (equation I) or for addition to ethyl 2-butynoate to

(l)

0I)

r -/Sn(CHr), HC-C(CH)"X --:+ CHr:C- -(CH')'X (x = Cl, OH,oR) CH3C-CCOOC2H5

-t

RCI{O r

turated amides. This reactrc ticide.

RCH:CHCHO

+ I -t m-q

(E) CH3(CHr)4CHO+ (C.tlrV

t

o tl

I

(E)-I + (CuHr)rAs'CH,C\-l B'

7A%

3

(CHr)rSn-^

(CHr\Sn-^_

^./H

(E)-4

nr.CooCrHt

cH/--':'"

cHau:t\coocHs >99:
Q)-4

(equationII). Thisreactionis a general provide(E)-3-trimethylstannyl-2-alkenoates of c,B-acetylenicesters.on the other hand, the (z)-1,4route to (E)-1,4-adducts adductscanbe obtainedby useof the phenylthiocuprate [(cH')'sncuSC'H']Li (2)'

0II)

(ll)

CH3C-CCOOCTH.-:+

(Z)-4 +

Triphenylanoniun c-1 tively via arsoniumylides l involvestransylidationof a 1

(E)-4

98:2 rE. Piers,J. M. Chong,andH. E. Morton,Tetrahedron' 45' 363(1989). Triphenytarsoniumylides, 10, 445; 13,137. lJnsaturatedamides.r The organoarsoniumbromide 1, preparedas shownin equation (I), reactswith aldehydesto form (E)-unsaturatedor (2E,4E)-diunsaO

I

(C6H5)3PCH(CHJ I-

(C.4)rAs'Cl

CF

O

^

(r) (cuH,),As+ BrcHre-N\

(D

/) JA+

, _ _ _ l -L/ - - \ (c6HJ3ArlcFIrc-N\J

I Y. Z. Huang, L. Shi, J. Yaq. r Y. Shen,Q. Liao, and W. C)ir

Triphenylarsoniumylides lqco,

', \ ('hem.Comm.,153(1989)

(ll) RCHO+t

:v\fi).

i

#RCH:CHCo-N

+r rl-sg(1988). ,.:..ir.Res.,177,C9(1988).

\-J

)

E, lN% turated amides.This reactionprovidesa route to pellitorine (2), a natural insecticide.

,r ,r/. haveprepareda number of sulfide, annvl)copper(I)'dimethyl is r\pe for conversionof l-alkynes rr additionto ethyl 2-butynoateto l,',

RCH:CHCHO+ r J;;;-'

R(CH:CH),C"-(I

(E)

2E,4I-,l00Vo

+ (crHr)rAs.c4cHo I cH3(cHr)4cHo Br-

I

o il

\-J

cg,(c r\),.,?-

ctlo

(E)-r

LCo"

- 't9% (E)-1 + (C.H,),As.CH2CNHCHTCH(CH3)2 rCHr)rSn-

B' -C::a' ..COOC2H'

cH,1CU,)$,Az

(Z)-4

>,)r < I

? CNHCH'CH(CH3)'

-H

cH;

H.

2 (8,E,l007o)

Brr,)n II). Thisreactionis a general , ( )n the other hand, the (Z)-1.,4(2). rurr.tte[(CH.).SnCuSC.H']Li , J,'-l +

Triphenylarsonium ethylide. trans-Epoxidescan be prepared stereoselectively via arsoniumylides under specialconditions(10,445).A simpler method involvestransylidationof a phosphoniumylide to an arsoniumylide (equationI).'

(E)-4

98:2 0)

r, ,: {-(.363(1989).

r t rrrmide1, preparedas shownin or (2E,4E)-diunsaf-un\aturated

- CH, 2(C.H.).As -------:--:-:--.

(c6H5)3PcH(cH3)' I-

(CuHr)rAs.CH-

-(c"H'lP:O

I

^^)c:c(c",l,l# cF; )--

o

. t l

At P. A'AH H

c:c(cH,), CF,

C.H.t,AsCH,C-N\

Ba I

\-

/

tY. Z. Huang, L. Shi, J. Yang, and J. Zhang, Tetrahedron Letters,8,2159 (1987). 2 Y. Shen,Q. Liao, and W. Qiu, J.C.S.Chem.Comm,,1309(1988).

fta-t 352

Triphenylphosphine-Diisopropylazodicarboxylate

diacetate'12'548' Triphenylbismuth a-Amino esterscanbe monophenylated N'Phenylationof Jo*;no ol;ia'' by in cHzcl2at 25owhencatalyzed (hisin highyieldby reaction*ni'ttr",l,ui(oAc), esters anddibasicamino t"::t.cult' Cu(O)or Cu(OAc),'"tilil;t';ltt not phenylateo" tidineor arginineesters)are

f.", coocH'

c6H5CHpNH

2

fuH,

937(1989)' Letters'30' I D. H. R. Barton,J'-P'Finet'andJ' Khamsi'Tetahedron

COOCH.

HCONH 4

halide-Potassiumr'butoxide' halide Triphenylmethylphosphonium ihe reaction of a triarylmethylphosphonium in a wittig_smitesrrr";;;;isuch as 1 results Ot*tUoxylic acid halide imide and a base with an *-n"t" a pyrrolidinedione provide to a Smilesrearrangement by followed reaction Wittig (2\;

9H, -cHc"H,

cH+< roc(Brr --;-

f"'ff ,0n.", + (C.H,)TPHCHCH'

ctoct-cc:-., CH,

OA"AO I CH,

I T. Kolasa and M. J' Mlllet'

Tetrahedron It

mp Triphenylphosphinehydrobromkh' ( sas).' T etrahydropyranylationol tcrt
' J . D . S u r m a tai sn dA ' O f n e rJ' O ' S ' ' l ' D'-S'Shin'andJ ,; ;ot];, C. Mioskowski,

7

(19511' , J. F. BunnettandR. E. zahler,chem'!t:: 4?.'362 V' Huch'Ann''913(1988)' and Pfordt' u' ' L. Capuano, n' n"tungt'lrtni'itg"r' Triphenylphosphine-Carbontetrabromide' ethers primary and.secondarytetrahydropyranyl RBr. ;;;t; ROTH,.___> 2P(c'H5)3/ with reaction by *ith.inu"rrion areconvertedto ttreconJsi""otiJt:"Joe with tertiary tetrahydropyranyl re.alti.on ttre yieid'' CBr,r in CHrCl, in ls-8iZo The yield in the with addedLiBr (1.5 equiv.). ethersis bestcarried"rii""ina* under the standard asopposedto a 44% yieid only examplereporteois 6Zn'' conditions.'

557(1989)' Letters'30' rA. Wagner,M'-P'Heitz'andC' Mioskowski'Tetrahedron azodicarboxylate(1)' Triphenylphosphine-Diisopropyl oxidizedby the acids. ihese substratesale oxidation,r esnr-'7r'(.-il*ino estersor adducts' a-positionto give either a-keto Mitsunobu reagent(1) ai the ester2 is oxidizedto methyl For example,tf'" N-u"n'Vioxypt'enytgtycine.methyl of N-formylphenylglycine In contrasl,t"uction phenylglyoxalate3 in 93% yreld' (5) in 80% yield'' airiazoline methvl ester(4) resultsin

tetreflromlrr 2,4,6'Triphenylpyrylium -" Phoioseniitized dehydrogcnotiot'l-' ( tizer providesflavonesin moderate .u.ried out with CAN or DDQ'

2 R'-t

.,_loyCuH.R'-p . ! ll I

\ r o

P.'= H, CHr,OCH' R' = H' OCHI

I M. J. Climent,H' Garcia'S' lbona' V ( le8e).

Tris(dibenzylideneacetone)diP{ra' Isomerization I cYclization d and Pd catalyst effects isomerization

(chloroform) Tris(dibenzylideneacetone)diP&llsdium

r'

C"H. r\ .rn be monophenylated l, .rt 15"when catalyzedby d Jrhasicaminoesters(his-

THF,25" t -coocH3 "" -#

.4.

c6HscHroNH' )

r

t " -

82%

HCoNHAcoocH3 ride. mc'thr lphosphoniumhalide nrJc:uch as 1 resultsin a pr,'rrdea pyrrolidinedione

9H, -cHc.u.

r-s--I--4

, ' " 'I

\

^A-,Ao N

CH,

I

oAcoocu, 3

C.H.

z::r'i. 30,937(1989).

9uH'

c6H5v'coocH3 -/\ \CO2-i-Pr N. \\:-NCOr-i_h \ / 5

4

I T. KolasaandM. J. Miller.Tetrahedron 4661(1988). Letters,29. hydrobromide'm.p. 189".Preparationfrom P(C.H,). * HBr Triphenylphosphine (gas).' Tetrahydropyranylation of tert-alcohols.2 The reaction of terr-alcoholswith dihydropyranin CH'CI at 0'catalyzedby this reagentprovidestetrahydropyranyl ethersin 78-96% yield. I J. D. Surmatis (1963). andA. Ofner,"/.Org.,28,2735 r V. Bolitt,C. Mioskowski, (1988). Letters,29,4583 D.-S.Shin,andJ. R. Falck,Tetrahedron

t

r:

- 1 n r r . . 9 1( 139 8 8 ) .

rr :ctrahydropyranyl ethen r 5r reactionwith 2P(C.H.). t(i:r.rr\ tetrahydropyran!'l . r ; r l u r r. ) . T h e y i e l d i n t h e rrclri under the standard

- i : : , ' , 3 0 .5 5 7( 1 9 8 9 ) .

6t:.::.\ are oxidized by the r .r-icto esters or adducts. ter I n oxidized to methrl L,': \-formylphenylglycirr

2,4,6-Triphenylpyrylium tetrafluoroborate,E,520.Supplier:Aldrich. dehydrogenation.t Irradiation of flavanoneswith this sensiPhotosensitized hasbeen tizer providesflavonesin moderate(-60Ea) yield. This dehydrogenation carriedout with CAN or DDQ.

,y'tt.o-.-zCuHoRz-p

R'+- ll W

|

o

i::

?'Vo-rlCuHoR'-p

R'-f ll +T526esc

ll

\i[,

o

R'= H, CHr,OCHr R2=H, OCH.

' M. J. Climent,H. Garcia,S. Iborra,M. A. Miranda,and J. Primo,Heterocycles,29,115 ( 1eSe).

Tris(dibenzylideneacetone)dipalladium (chloroform), (dba).Pd,'CHCI. (1). acetates (carbonates).' This of a-dienyl-a-allyl Isomerizationlcyclization Pd catalyst effects isomerization and cyclization of these substrates to vic-disubsti-

354

(chloroform) Tris(dibenzylideneacetone)dipalladium

Tris(6,6,7,7,E,8,&heptrfi ooro2J-

o

Carbonylation of allylic a this and a few other Pd(O)complc providesa route to (E)-p,1.unsar allylic acetates.

tl

1) qH,OCOCH(CH:CH1L, r 2) CtL-CHCHCIL

'

\

/

o

(c6H5sor)rcH,

1--Z-\4CH,

(c.H.so,),c -'\-^-.cHPAc

3) AcrO

^-- | r' LioAc, ou-o'tJcxrn, a -

HoAc,

CH'oAc

cuH5so,v^1Az

f|l,

co'

c.HMoAc

c6H5soi\&cH,

OAc

= 9:l') Granslcis tuted cyclopentanes. This reaction can also afford cis-fused bicyclic products with an er?do-substituent(equation I).

cHroAc "r")

(r)

A'ol) -I, HOAC,105'

;#
so2c6H5

Reductive cyclization of 1,6-diynes.2 Cyclization of these substratesto I,2dialkylidenecyclopentanes can be effectedwith 1 and a phosphineas catalystand triethylsilane(1O-foldexcess)in placeof polymethylhydrosiloxane. Examoles:

;"

7C-CH

X

t--g:69

;

:{--r"' "

I B. M. Trost and J. I. Luengo..{a 5 ' B. M. Trostand D. C. Lee. rDd . ll I S.-J.Murahashi,Y. Imada.Y. Taob ( l 988).

Tris(diethylamino)sulfonitr

56Co

o

of:

hcH,

-r o.-Halo carhanions.t TASF r halo carbanion as shown bv addu

TAI

rrt.: 0) (cHJ3sicHcl:

are stableat 25o,in contrastto 6d peraturesabove - 110'. Horevcr. romethyl)trimethylsilane. I M. Fujita,M. Obayashi, andT. Hnr

(E = COOCH3) R"SiO

R.SiO

CHCH,OCH.

.r,,L.c-ccHrocH3

I I t l VtcHrc:c'

86% |

|

\,ry H

FCH,

Tris(6,617,7rErE18-heptefl uoru,2"2{ -praseodymium,Eu(fod). or P(fq Diels-Alder catalysc.t Tbclr rate and endo-selectivityof Dicb-r esters.

Tris(6,6,7,7,E,E,8-heptafluoro-2,2-dimethyl-3,5.octanedionalo)europeum or -proseodymium

--/'yCH,

355

Carbonylation of allylic ocetates.s This reaction is effectedby catalysiswith this and a few other Pd(O)complexes,but requiresbromideion as a cocatalyst.It providesa route to (E)-B,1-unsaturated estersin generallyhigh yield from primary allylic acetates.

z-1,CHrOAc Pd(0), NaBr, C,[OH CO, ,-Pr,NC,H.,50'

.,l-rlllf"i"oo"

c,Hs.^oAcJ--c6l1s,^cooc,H5 *cH'oAc

P..-z\a,;nan

-"'yCH,

OAc

COOCrfl

le,..r=9:1)

u.cJ bicyclicproductswith

OC"'*Oacooc.* ' B . M . T r o s ta n dJ . L L u e n g oA , m . \ o c . , 1 1 0 , 8 2 3 9( 1 9 8 8 ) . 2 B. M. Trostand D. C. Lee, ibid.,110,7255(1988). r S.-J.Murahashi,Y. Imada,Y. Tankguchi,and S. Higashiura,Tetrahedron Letters,29,4945 ( 1988).

Tris(diethylamino)sulfonium

so2c6H5 ('i :he\c substratesto 1.2lh,'.phine as catalystand J r , ' . 1l ( ) \ a n e .

?cll scti

CIICH.OCH.

( /YCH.

difluorotrimethylsiliconate (TASF), 10, 452. s-Halo carbanions.t TASF reacts with c-haloalkylsilanes to generate an ohalo carbanion as shown by addition to aldehydes (equation I). These carbanions

(D (cHJ3sicHcl,;f:i''

t-cHcl,l#

C6H5CHCHCI2 OH

are stableat 25o,in contrastto dichloromethyllithium,which decomposes at temperaturesabove -110'. However, a similar reactionis not observedwith (chloromethyl)trimethylsilane. I M. Fujita,M. Obayashi, andT. Hiyama,Tetrahedron,44, 4135(1988). Tris(616r7r7181818-heptafluoro-2,2-dimethyl-3rS-octanedionato)europeum or -praseodymium,Eu(fod), or Pr(fod).. Diels-Alder catalysts.r These lanthanide complexesmarkedly improve the rate and endo-selectivityof Diels-Alder reactionsof cyclopentadienewith allenic esters.

Tris[2-(2-methoxyethoxy)ethyurmine

,-[7cHCH3 co2c2Hr co"c"H.

+ Eu(fod),

endo

z.)i I 5 . 4I:

rangement to grveat TlVoyield.Normall{ I arereplaced b1'h1

cl I l

'R. P.Gandhi, (1988). M. P.S. Ishar,andA. Wali,J.C.S.Chem.Comm.,1074

^

4-("-o t t l CI,VCI

Tris(616,7,71818r8-heptafluoto-2r2-dimethyl-3,S-octanedionato)ytterbium, Yb(fod),. Diels-Alder reactions with cycloalkenones.t(E)-l-Methoxy-1,3-butadiene undergoescycloadditionwith cyclohexenone at 160'to afiord the endo-adduct(2) in 47Voyield. Catalysiswith the usualLewis acid resultsin resins,but Yb(fod). catalysisresultsin cycloadditionat 110'and leadslo endo-andexo-3in 55% yield. The adducts3 arise from a Diels-Alder reactionwith the dienone4, which is formed when 2 is heatedat 100"with Yb(fod)r.

o ,\

(,lJ .

s

H,(

H 3 = 1.5:1) (endolexo

I Yb(fod)3160",47% 110.,55%

,rofr* o

Wittig reactions., phenylphosphonium b are negligible,but car dramaticincreasein r transfercatalyst.Bcsr pendedin THF with T technique,alkylidenc yieldsof 60-95%.

ll I' Yb(rod)' ) 3 (endolexo= 1.5: I )

m 4

'F. Fringuelli, (1984) Org.,53,4607 A. Taticchi, andE. Wenkert,J. L. Minuti,L. Radics, (TDA-1), 13,336-337 Tris[2-(2-methoxyethoxy)ethyl]amine ; 14,341-342. Smiles rearrangentent,t Attempted N-alkylation of 3-(2,4,6-trichlorophen(1) catalyzedby TDA-1 is accompaniedby a Smilesrearoxyacetamido)pyridine

D>-irc.r t

Glycosylation.. 1 phase-transfer catalrz anion of the pyrimidin the glycosylationproc excessof 2 is required

Tris[2-(2'methoxyethoxy)ethyl]amine

'HCH,

z[zcHcn,

+ ll)--uf..co,c,H5

t

(2) in 63rangementto give an N-alkyl-3-(2,4,6-trichlorophenylamino)pyridine 7l% yield. Normal N-alkylationof L obtainswhen one or two of the chlorinesof I are replacedby hydrogen.'

2'5:r 5 . 4I:

: 'H .

.n

357

( , ) t n m . 11 0 7 4 ( 1 9 8 8 ) .

lenedionato)ytterbium' A

r E )-l-Methoxy-1,3-butadiene (2) B l r() afford the endo-adduct d rc.ultsin resins,but Yb(fod). I r ' ,'ntlo- andexo-3in 557oYield. )n *rth the dienone4, which is

at-tr* |

*

p

cr,

")N{

./-r\

\_N

(

)

/fcl

\___7

cl/ 2

H 3 llri

I

:) zro = 1 . 5 1

fi_:il'

= 1.5:l) 3 @ndolexo

( 179 8 8 1 E \ \ ; n k e r tJ, . O r g . , 5 3 , 4 6 0 1-1: :n-337; 14.341-342. il.:',,n of 3-(2,4,6-trichloropheoby a Smilesrear' r. .:.;rrmPoni€d

Wittig reactions.3 Yields in the reactionof an aldehydewith cyclopropyltriphenylphosphonium bromide (2,95-96) under the usualconditions(NaH, DMF) are negligible,but can be improvedto about l5Vo by addition of 18-crown-6.A dramaticincreasein yield is obtainedby use of NaH in THF with TDA-I as a transfercatalyst.Best resultsare obtainedby heatingthe phosphoniumsalt suspendedin THF with TDA-I beforeadditionof the carbonylcompound.With this can be obtainedfrom carbonylcompoundsin technique,alkylidenecyclopropanes vieldsof 60-95Vo.

pi1c,n,y,ni#I'',

[",",1,r{] #

:>.

Glycosylationa The p-o-ribonucleosidetubercidin (a) can be preparedby phase-transfer catalyzedglycosylationof the a-o-ribofuranosylchloride1 with the anion of the pyrimidine2 mediatedby TDA-1. Since1 lacksa neighboringgroup, In the absenceof TDA-1, a two-fold the glycosylationproceedsstereospecifically. excessof 2 is requiredfor glycosylationof 1, and the yield of 3 is only 34Vo.

Tris(trimethylsilyl)silane

CI

I

TT =^^T

R3SiO

by UV photolysisat 40'or by dibenzorlpc quantitative. It is as efficientas Bu.SnH for tnttn radicalreactionswith alkenes.r

TDA-I, KOH

J$n,sio

K")

CuH,,l+ CHr:ggL-

X

LAI

o-.'ro c".nc", NH,

I

TaO

CHr:CH(CH,).Bt

w

3 | 1) CFICOOH | 2) NHi

\Ntx

I

HO

-

]a"J H

OH OH 4

TDA-1 in ether RMgX ITDA'| .s Grignardreagentsform a 2 : 1 complexwith thatcanbeobtainedasapowderedsolidafterevaporationofthesolvent.The or cyclohexane' complexesare solublein THF but not in ether,aromaticsolvents, as regularGrigreact complexes The 1.10". below They are stableto temperatures The slightdifference nardreagentsin mostrespects,but aresomewhatlessreactive' ketones.The comof presence the in of aldehydes is useful for selectivereactions than a regular extent greater a to enones to plexes also undergo l,4-addition Grignardreagent. rW.E.Truce,E.M.Kreider,andW'W'Brand,Org'React''lE'99(1970)' (1989)' 2A. Greiner,Tetrahedron Letters,30,931 (1988)' 3J. A. Stafford andJ. E. McMurry,ibid',29,2531 seea/soF. Seela,H.-P.Muth,andU' aH. Rosemeyer andF. s"tii, ttrtr.',71, i573(1988); (1988). 670 Bindig,Syntlrestr, 45' 171 5A. Boudin,G. Cerveau, C. Cnui,,R. J. P. Corriu,andC. Reye,Tetrahedron'

(re8e).

(1)' 'This Ttis(trimethylsilyl)silane, [(CH3)3Si]3SiH effectiveas Bu,SnH for reduction of RX is as siianel Reductionof RX.' The reductionscan be initiated by a free-radicalreaction and is moreoverlesstoxic.

I C. Chatgilialoglu, D. Griller.and\1. Lcse ?Preparation: H. BiirgerandW. J. Krhan-. r B. Giese,B. Kopping,andC. Chatgultal

Tris(triphenylphosphine)nichel(0).Thrs I reductionof BrNitP(CoH.),1with Zn-Pl ArCl --->ArCN. This Ni(0) catalu KCN in HMPT or CH.CN at 6{f . Cou! to only a slightextent.l

cl ,\.oc

f

3

il

N(orHxPr *xcN s ,l q6

'

\,,/

I Y. Sakakibara. F.Okuda,A. Shimobavas Bult.Chem.Soc.lapan,6l' 1985(l9BE)

Ttityl chloride (triphenylmethyl chlond N-Tritylamino acids. Direct reac videsN-trityl derivativesin low yield. A reactionof trimethylsilylestersof S-rn in refluxing chloroform, which prorrdc hydror.r yield. Trimethylsilyl-protected

conditions.' 4-Polystyryltritylamino acids can bt methylsilylestersof amino acids.:Thc

Trityl chloride (ftiphenylmethytchloride)

359

by UV photolysisat 40'or by dibenzoylperoxideat 50".Yieldsof RH areessentially quantitative. It is as efficientas Bu.SnH for initiation of intermolecularor intramolecular radicalreactionswith alkenes.3 I, AIBN,

. R.Sio

70-eo" , C6HTCH2CH2CN

CuH,,I + CHr:gggtr1

r, ArBr

CHr:6g,.";,e,l9i 3

9H'

1A1--

\J

93Vo 1) CFTCOOH 2) NH,

\-,J ZVo

rC. Chatgilialoglu, D. Griller,andM. Lesage, J. Org.,53.3641 (1988). 2Preparation:H.BiirgerandW.J.Kilian,"/. Organometal.Chem.,lB,Zgg(1969). r B. Giese,B. Kopping,andC. Chatgilialoglx, Tetrahedron Letters,30,68l (19g9). Ttis(triphenylphosphine)nickel(0). This Ni(0) complexcan be generatedin situby reductionof Br,Ni[P(CoH,),]with Zn-p(CoH.).. Ar{l --->ArCN. This Ni(0) catalysteffectscyanationof aryl chlorideswith KCN in HMPT or CH.CN at 60'. Couplingof aryl chloridesto biphenylsoccurs to only a slightextent.l

.omplex with TDA-1 in ether trp6rationof the solvent.The or cyclohexane. na:rcsolvents, rnnieresreactas regularGrigI re.ictive.The slightdifference )reienceof ketones.The comgrcrrer extentthan a regular

CI y').ocH I ll

Ni(ollrMpr, +KCN

o""'nrlr$fu

quul

\./

I Y. Sakakibara, F.Okuda,A. Shimobayashi, K. Kirino,M. Sakai,N. Uchino,andK. Takagi, Bull. Chem.Soc.Japan,61,1985(1988).

r,:.':. lE, 99 (1970). I a-, ' F Seela,H.-P.Muth, and U. rc (

Reye, Tetrahedron,45, 77l

s Bu,SnHfor reductionof RX The reductionscanbe initiated

Trityl chloride(triphenylmethylchloride). N-Tritylamino acids. Direct reactionof trityl chloridewith amino acidsprovidesN-trityl derivativesin low yield. A superiorroute to thesederivativesinvolves reactionof trimethylsilylestersof N-trimethylsilylamino acidswith trityl chloride in refluxingchloroform,which providesthe N-protectedamino acidsin 88-92% yield. Trimethylsilyl-protected hydroxylor thiol groupsare not cleavedunderthese conditions.l 4-Polystyryltritylamino acids can be preparedin the same way from the trimethylsilylestersof amino acids.2TheseN-protectedamino acidsundergousual

360

TritYl hexachlororntimonrte

couplingreactionswithaminoacidesters,ofteninquantitativeyield.Thepolymeric yield' proi".tiu" group is removedby p-TsOH, HCl, or TFA in 75-90Vo I P.Mamos, Ann', 1083(1988)' andK. Barlos, C. Sanida, andP. Sotiriou'ibid" 1079(1988)' , i. sartos,D. Gatos,I. Kalitsis,D. Papaioannou,

I T. Mukaiyama, P. Leon, and S. Kobal-ahr.

Trityl perchlorate. Addition of silYl enol ertcn rc 4 ditions becauseof the sensitivit;-of dr

Tiityl - Achloride-Tin(Il) l l y l k e t e n e d i t hchloride' ioacetals.Inthepresenceofthesetworeagents,ketene dithioacetals(1)reactwithallylmethyletherstoprovideallyl.substitutedketene and Sncl is an equally dithioacerals(equationI). Th; combinationof clSi(cH),

-"'X cH. (r) H

- i"' ?t"' :fl-*9-! t",^*
,S> '

#I *. sH,A.^c4 s / r

c

H

o

(r)

osi(cHr\ + C.HTCH:C}|C

CH,

, 3 ( 9 1: 9 )

effectivecatalystforthissubstitution.Asimilarreactionoflcanbeeffectedwith a,p-unsaturatedortho esters(equationII)'' OCH

(r)1+cH,Jru

O

QH,

tr:l#b'.",oA&tl ts/ cH!

catalyticamountof trityl perchloratclc at Cotend to undergol,Gaddition rrd

rT.Mukaiyama,H.Sugumi,H.Uchiro,andS.Kobayashi,chem'Letters,1291(1988)'

o Trityl hexachloroantimonate,TrSbClu(1)' Reactionofa,p-unsaturatedacetalswithsilylnucleophiles.Thistritylsalt acetal(2) of cinnamaldehyde is an efficientcatalystfor reactionof the dimethyl B-azidoketones'The silyl nucleophilesto form 1'D-unsaturated with successive by the Staudingerreaction'r azidegroup can be reducedto an amino group

9cH' t c6H5

,

.^ocH3' t

N.

9 S R , f c H'l , o o l N's(cH!\ t I ll I ' cuH,c:cH,.+ 85% l_crn,A.,A4crnl - ,- L

A

c,H,A'AAc,H,

H,o P(c6H)',

-#-

NHt

I

cuH,AAAcuu'

tl

/,.,?o ll

|

R/'\/ (R = ,-Bu)

osi(c I

+ C.H,CH ,CH:C

Trityl perchlorrle

a::::.rtiveyield.The polYmertc T \ r n 7 5 - 9 0 %y i e l d . ) : ::rrtr.r. ibid.,1079(1988).

rT. Mukaiyama,P. Leon, and S. Kobayashi,Chem.Letters,1495(1988).

Trityl perchlorate. Addition of silyl enol ethen to o-quinones.l This reaction requires mild conditions because of the sensitivity of these quinones, but can be achieved with a

)! :1.\e two reagents,ketene ketene r,.r :.1eallyl-substituted t( ll t. and SnCLis an equallY

o

(l)

CH"

" l s :- cH,\4=rz")

osi(cHJ3

tl ):-o

ll cH3/'V

oSi(CH3)3

|

r'.ro.

ry + c6H5dH:cHcH3

CH, H

o\

CH,

- - ' J

/

\ _ ,

CuH,

S

CH,

361

3 ( 9 1: 9 )

,rol n.o'

+ '

rlrt'n of 1 can be effected with

on\-

I rcHCoc6H5

"o-{

,"!&,) (1988). h: ( rrcnr.Letters,1291

gH,

4.",

catalyticamountof trityl perchlorate(equationI). o-Quinoneswith a bulky group at Cotend to undergo1,6-additionwith silyl enol ethers.

o

osi(cHJ;

R osi(cH3)l

I nucleophiles. This trityl salt I :,clal (2) of cinnamaldehYde aru:.rtedB-azidoketones.The reaction.t thc Staudinger

).O"

+ cuH'cH'cH:cHCuHs +

o

*),') (R = ,-Bu) -

cH ,I o o \-,,,\-

il

NH"

I

N,s(cx*, | -ss*

cuHl

cH2c6H5

61%

lHlO'

*Yl[-rr"''' Y

O

,.\4A".",

Yo^cH2c6H5 OH

le|

Thityl perchlorate

Aldol reaction betweeno.rp-acetylenicketonesand sityl enol ethers. TrClOo is an efficientcatalystfor 1,2-additionof silyl enol ethersto o,B-acetylenic ketones.2 OSiR3

O

9 CH, OSin,

rrc,o. I ll ,AX. cHrc-C=c-CuHr+C.HrACHrffi c;+, o

l

cu,c-c=c-si(cH3)3

l

-\.

--a.",

osi(cH3)3

r

+ (cHr)rcHCH r-t:CH,

#t

o o H

i l l

-C (cH3)'CHCHTCCH2C I CH,

:

,-CHt

Ultrasound,(((. Diels-Alder reacfions.t Ulu with o-quinones.and also impro obtained in the absenceof a ro pigmentsof Chinesesagerespor exampleis the synthesisof 3. rh reactionof the dieneI *'irh thc gt improvesboth the regioselecrrrr

"YV

CSi(CH3)3

(trarslcis= 65:35) ' Y. Sagawa,S. Kobayashi,and T. Mukaiyama,Chem.Leuers,llli (l9gg). zS. Kobayashi, S. Matsui,and T. Mukaiyama,ibid.,1491(1988).

o

n

\,^t

(

.:

oi'WCH' cH3to CH, c6H6'A, 10 kBar,25" ((t',neaL45o

l5c 7,1{ 16C

o ""\o CH.

Review.2 Ultrasound irradrarr with many organometallic reagent -zinc reagents(64 references;.

' J . L e e a n dJ . K . S n y d e r . , , l m. 5 . r r . _| : R. F. Abdulla,Aldrichim...{cra. !1. _

ol ethers. TrClOo cetrlenicketones.2

Ultrasound,((1. Diels-Alder reactions.t UltrasoundcanpromotesomeDiels-Alder reactions with o-quinones,and also improve regioselectivity. Highestyieldsof adductsare obtained in the absenceof a solvent. This reaction provides a route to some pigmentsof Chinesesageresponsiblefor the biologicalactivityof Dan Shen.An exampleis the synthesisof 3, the acetonideof tanshindiolB. Thus the thermal reactionof the dieneI with the quinone2 gives3 and4 in the ratio 1:1. Sonication improvesboth the regioselectivity and the yield.

-H_

^? f"' "Y^f,

-\^

I

L

A: i5) l!\\ |

-si1cH,;,

| I

\Aol

il ll

-

^"'\A'zcH' -\ : -cH. cHsto

.2

>

1) SiO,,O, 2)DDQ

I

CH, l57o C.Hr, A, l0 kBar,25o 737o ((t.,neat,45o 76Vo

o

q ' ' CH, lro

r

CH

CH, 3

4 1:l 7:l 5:1

Review,2 Ultrasound irradiation improves the rate and the yields of reactions with many organometallic reagents, particularly of organocopper, -lithium, and -zinc reagents (64 references). r J . L e e a n dJ . K . S n y d e rA, m . S o c . , 1 l 1 ,1 5 2 2( 1 9 8 9 ) I R. F. Abdulla,Aldrichim.Acta,21,3l (1988). 363

F(CH,)Si -'

Vanadyl trichloride (Vanadium oxytrichloride)' VOCI. (1)' acids. Oiidative decarboxylation-deoxygenation of 3-hydrorycarhoxylic 1 equiv' with chlorobenzene in heated Theseacidsare convertedinto alkeneswhen [2, 1,8-bis(dimethylamino)naphthalene]' eachof VOCI, and Proton Sponge@

o o H ll

A HO,

|

/"H

x CH;

v6rrs

1 . 2 . c ." H-.\ J c6H,cL^, Bqo

CH3

/ H

o o H ll

X

I-

Ho- Xi.r.rr,.zlt.u

CH;

cH. \ CH,

c^H.. " "\

cw:Nc6H'cH"2

,*%-

/

!H,

__/a^-_ CH,

\_

ascar with Pd[P(C.Hr).1. in couplingof the rinrb I K. Tamao, T. Kakur.\t | lX 98-1 Tetrahedron,39.

Vitamin Bp (H1'droroc Isomerizatioa d qt effectedwith strongba* to opticallyactivealhlrc B,r at 25". Thus clclopc ee. The rearrangemen is more typical.

CH.

Y;;

(1989)' I I. K. MeierandJ. Schwartz, Am. ioc.,111,3069 RCH = CHSiF(CH)z(1). The reagentsareprepared Vinyt(fluorodimethyl)silanes, with copperfluoride' by ieactionof the correspondingvinyl(chloro)silanes much 1,3-Dienes; vinylarenes.rThese fluoro-substitutedalkenylsilanesare iodides vinyl with reactions in coupling more reactivethan trimethyl(vinyl)silanes vimediatedby TASF and a palladiumcatalyst(14, 340-341)' Oddly enough' relonger require and 1 than are slightly lessreactive nyl(difluoromethyl)silanes The actiontimes,and a trifluorosilylgroup is completelyinactivein this coupling. particularly components, couplingproceedswith fetentionof configurationof both Pd cal, TASF

CH.(CH)s-yay'\S(CHJTF* | --7

pur),cH,

#

cHr(cH), _r,ryVr--(cHJ5cll3

CH3(CHJr, ,S(CH3)f + t4 \-'

\:/

lcoCrq

'

_-' ,Yh

.r,(.*L),\_/Crcoctr'

o I H. Su. L. Walder. Z.<J

Vitamin B12(Hydroxocobalaminhydrochloride)

F(cHJ2si

/si(cHr)rF

+ 2IC6H5 ;-

365

cuHrr_rcuH, (ZlE= 4:l)

\()(, (l). ol 3-hydroxycarboxYlic acids. with 1 equiv. c.j rn chlorobenzene lmct hvlamino)naPhthalene].

/ ,F:1 cH3 H c-H. \

r

+

CH,

/

I K. Tamao,T. fatui, M. Akita,T. Iwahara, R. Kanatani, J. Yoshida, andM. Kumada, Tetrahedron,39, 983(1983); Y. Hatanaka andT. Hiyama, J. Org.,54,268(1989). Vitamin B, (Hydroxocobalamin hydrochloride),l. Isomerization of epoxidesto allylic alcohols.t This rearrangementhas been effectedwith strongbasesand variousLewisacids.Enantioselective rearrangement to opticallyactiveallylic alcoholscan be effectedwith catalyticamountsof vitamin B,, at 25o.Thuscyclopentene oxiderearranges to (R)-2-cyclopentene-1-ol in 65% ee. The rearrangementof the crs-2-butene oxide to (R)-3-butene-2-ol in 267oee is more typical.

CH. -

L- \

with Pd[P(C.H,),1, ascatalystandDMF assolvent.TASF canbe replacedby Bu.NF in couplingof the vinylsilaneswith iodoarenes.

cH" ' CH,

OH

O"*ed

h-

I r The reagentsarePrepared I [r;. rrith copperfluoride. are much x:r::rtcdalkenylsilanes with vinyl iodides rp.r:rrreactions It i-lrr--141).Oddly enough,vir\r :hrn I and requirelongerre[c.\ rnactivein this couPling.The particularly | ..! ^rrrhcomponents, i:,r:..

TASF

_* cH,'cH)5'_//'

!

"/^(cHJ5cH!

-!r

cH,cH,),\Jococq

(R, 65%ee)

o

A CH,

CH, (crs)

r H . S u , L . W a l d e rZ , . - d . Z h a n g a, n dR . S c h e f f o l d H.e l v . . 7 l , 1 0 7 3( l 9 S U ) .

Ytterbium(0)' Yb. ketones Reaction of Yb(O) with diaryl Cross'couplingreactionsof ArtOAr' nucleophilic' to group from electrophilic changesthe reactivity oi-'i" tu'Uonyl diaryl ketonescouple with other Thus in the presenceor ;;s tanttranoiJmetal' and 1'3-diols' to give pinacols,a-hydroxyketones, ketones,nitriles, und "po*id.. a' respectively,via the intermediate

)v Org',53' Fujiwara'and H Taniguchi'l. ' Z. Hou, K. Takamine,0' Aoki' H' Shiraishi'Y 6077(1988).

Zeolites. These natural I molecularsievesa someorganicPho zeolitesby treatmc These silicates.dr toP deoxybenzotns

o

i l ^

C,HrytT: cF5 I CrHu + Li-X

of 1 in benzenet zeolite Li-X reer selectivecleava5

I D. R. Corbin.D.

Zinc borohydril RCOCI - | catalyzed bl' Tlv aliphaticac;"Iha bond.The b1-P

' H. Kotsuki.\'. I ( le88).

Zinc-CopPer co of a mixture of , black heavvsuq 1,4-Addida of RI to enon€ H,O (65-25:35

366

r,: \ h(()) with diaryl ketones ririlrophilic to nucleophilic. rl rilir)o€s couple with other d r , , \ \ k e t o n e s ,a n d 1 , 3 - d i o l s ,

Zeolites. These natural mineralsare alkali aluminum silicatesand have been used as molecularsievesand cation exchangers.Recentlythey have beenused to control someorganicphotochemicalreactions.du pont chemistsrhave prepared lithiated zeolitesby treatmentof sodiumaluminumsilicatessuchaszeolite 13x with LiNo.. These silicates,designatedLi-X and Li-y, can effect rearrangement of e-arkyldeoxybenzoins top-alkylbenzophenones in nearryquantitativeyield.Thusphotolysis

o il C.H

/P'g

t

CoH, t l T a n i g u c hJi ,. O r 9 . , 5 3 ,

l CrHo + Li-X

o H c.H.--J-- CH3

L

) CuHi

+ 2:l

2 54Vo

o PrPr c.Hrff c.H, + coH,d-cuHo(cH,),cH,-p HH 3

4

24Vo 4Vo

95Vo

of I in benzeneresultsin 2 and 3 as the major products.photolysis of I in the zeolite Li-x resultsin a trace of 3, with the major product uern! 4, formed by selectivecleavageof the bond betweenC_O and the CHC.H, group. ' D . R . C o r b i nD, . F . E a t o na, n dV . R a m a m u r t h yO , , /r .g . , 5 3 , 5 3 g( l49 S g ) . Zinc borohydride. Rcocl'--> RCHzoH.' This reductioncan be effectedby zinc borohydride catalyzedby TMEDA in ether at 0-40' in g0-95% yield. Both aromatic and aliphaticacyl halidesare reducedreadily without effect on a conjugated double bond.The by-productis TMEDA . (BH,),. ' H. Kotsuki,Y. Ushio, yoshimura, N. and M. Ochi.Bult. Chem.Soc.Japan,61, 2684 ( I e88). Zinc-copper couple.A highly activeZn-Cu couplecan be prepared by sonication of a mixtureof zn andcul (3:1 ratio) in an alcohol-water mixture(-65:3-5).A blackheavysuspension is formedwhichshouldbe usedat once.r r '4-Addition of RI to a.,p-enones.2This coupreand sonication effectaddition of RI to enones.Highestyieldsare obtainedwith r-proH/H,o (4:1) or proH/ H,O (65-25:35-75)as solventfor primaryiodides.C,H,OHiH,O (65;35)is the

36E

Zinc chloride

o

A (/

o

rrb'tr-A

f"'

+ (cH')'cHI :"o

cH'\/ycH,

\^cs(cH,b

* cHl

I CI

solventof choice for tert- or sec-iodides.Yields are decreasedin reactionsof oby a B-methylsubstituent. methylsubstitutedenonesand areparticularlydepressed for this addition. is suggested A radicalreactionoccurringon the metal surface I J. L. LucheandC. Allavena, (1988). Leuers,29,5369 Tetrahedron I J. L. Luche,C. Allavena, (1988). andC. Dupuy,ibid'29,5373 C. Petrier, Zinc bromide. (E)-a,p-IJnsaturatedacids,t Zinc bromide is the most effectiveLewis acid promoting a reactionof C,O,O-tris(trimethylsilyl)ketene acetal (1) with alfor acids.The ketene acetalcan (but not ketones)to form ct,B-unsaturated dehydes (I). in equation be preparedas shown 1) LDA

(D (CH3)3SiCH,COOSi(CH3L #*-

-

(CH,),SiCH:CtOSi(CE)3], I

o Example:

,tol *

Cyclization of giw substitutedat the 2- and G1 and NMR, and can be cenc Ag,O (10 equiv.) in CH.C quinonemethides can undc tors that can survivethe rnr the latter case,the initial p

C.HTCH:CHCOOH (E) CH'

CH,

t M. Bellassoued (1988). Leuers,29,4551 Tetrahedron andM. Gaudemar, Zinc chloride. Cyclopentadienes.tAllyl chloridesthat are monosubstitutedat the central allylic position, such as I, react with 1,3-dicarbonylcompoundssuch as acetyl(3) via an allylateddicarbonylinteracetone(2) to form acetylcyclopentadienes of l with 2 at -78". reactions mediate(a), which can be isolatedfrom

AGo. cltct + lmt H2

(

-s i(c Hr),

369

Zinc chloride

o

"",4.", * L.;-.,&.":l .."Y.", o

9"'

:'

cg(cnr),

in reactionsof orrc .lecreased re--cdbv a B-methylsubstituent. r\ .uggestedfor this addition.

o

;H.L1tn't-'{'tt'

I

I

u*.1-ro'

<:. . ,l98li). l } : . : e . 5 3 7 3( 1 9 8 8 ) .

r. :hJ most effective Lewis acid l . : . r , r k e t e n ea c e t a l ( 1 ) w i t h a l teJ .,eids.The ketene acetal can

-

Ctl,SiCH:ClOSi(CHJ3l, I

;i';L,,,.",1 t*t

^*cocHj

-

XtH,+2-+Wc", Cyclization of quinone methides.z p-Quinone methides,particularly those substitutedat the 2- and 6-positions,are stableenoughto be characterizedby IR and NMR, and can be generatedin fairly high yield by oxidationof a phenolwith Ag,O (10 equiv.) in CH,CI,. When substitutedby a suitableterminator,these quinonemethides can undergoLewis-acid-catalyzed cyclization.Suitableterminators that can survivethe initial oxidationincludeallylsilanes and B-ketoesters.In the latter case,the initial productundergoesoxidationto afforda cyclohexenone.

1l:CHCOOH r[-r

r'

:ir l5-sl (1988).

"",rr(,"n,

ll l \? |

I n:,,nosubstitutedat the central rrnr. compounds such as acetylll.: .:n allylated dicarbonyl inters ,'r I nith 2 at -78".

cH,-\*r,

"",-r.(-.",

lril ,cg,o,

ll

l) ZnCl, CHCI,

lt r \2 I

/t ^-. # / ' "r ._ # - A \_r -F.t' \"r, t

\r,1"",;,

>rcH, l

\r,1"".;.

370

Zinc chloride

' R. Koschinsky,T.-P. Krihli. ad I ' S. R. Angle and K. D. Tumtrrll. 3 F. H. van der Steen.H. Klcrln. . Letters,30, 765 (1989).

ocH3 - Ac.O

Zirconium sulfate. M onoace tal iza t ion ol g ho in large excess and catah'zed followed slowly by diacetalrzat decreasingthe concentratrono

coocH3

cH

ocH3

' F. H. Sangsari,F. Chastrette.el

l) Zncll 2) As,O

coocH3

o

c-aminoestersreactwith S-Lactams.t The zincenolatesof N,N-disubstituted iminestoformB-|actamsin60_g0voyield.Thereactioncanbe/r4ns-Selective, dependingon the substituenton the imine and the solvent' r)LDA

(cE)rNcHrcooCrH, Zg*

(CHJTN\----*'C5H5

cJtrcH:NcH' >

|

-l'

o2N-cH. C]15 THF 1) LDA 2)Ztf\

%)Io 8O9o

(CH3)TNCHTCOOCTH,rj (cxi sic=ccs:t'ts(ctl')'' cJr' ,

= 47:53 cisltrans = 70:30 (CH,),N

.c=csi(cH3)3

*-r,1a",y, = >99:
Zirconium sulfate 371 'R. Koschinsky, T.-p.Kdhli,andH. Mayr,Tetrahedron Leuers,29,5641 (19gg). ' S. R. Angleand K. D. Turnbul,.q^. ioi., iil, jl:o trqssl. 3F H' vander Steen'H. K'eijn,J. T. B. H. l^,-.u.r.i, andG. van Koten,Tetrahedron Letters, 30,765(1989). Zirconium sulfate. . .Monoacetalizationof glyoxal.t The reactionof glyoxalwith CH.OH or CTH,OH in large excessand cataryzedby zirconium surfateresultsin monoacetalization, followedslowlyby diacetarization. The derivedwatershourdbe eliminatedwithout decreasingthe concentrationof the alcohol(Soxhlet). 'F. H. Sangsari, F. Chastrette, andM. Chastrette, Syn.Comm.,lg,134309gg).

() v/\.ocH3 i l l

f,/y,coocH3 \AO

J

! :

()tl

/-\"ilI l

ocH3

i

/zycoocH3 \-..\o X ' c \ t c r sr e a CW t ith t t' :',ll.r-selective.

I, t, |

:-i

c=csi(cH3)3 I I

i-

\- ^..' 5l(Ln3J3

r.-r -- >99: < I

AUTHOR INDEX Abdel-Baky,S., 336 Abdulla,R. F.,363 Abe, H., 73 Abramson,N. L., 73 Aburatani,M., 53 Achiwa,K., 52-53, 54, 179,180 Achmatowicz, B.,45 A d a m ,S . , 2 4 8 Adam, W., 243,322 Agami,C., 268 Agarwal,S. K., 143 Ahlbrecht,H., 190 AhmadS , .,5t Aikawa,Y.,292 Aizpurua,J. M., 304 Akama, K., 15 Akbulur,N., 129 Akermark,B., 133 A k i b a ,K . , 3 7 A k i t a ,M . , 3 6 4 A k i y a m aT , .,73,340 Akiyla, K., 54 Albizate,K. F., 189 Alcock,N. W., 259 A l e x a k i sA, . . 1 2 2 , 1 3 7 ,1 5 8 .2 2 2 , 2 2 3 Alexander,R. p., 102 Allavena,C., 367 A l l e n ,E . E . , 4 7 Almansa,C.,270 A l m o n d ,M . R . , 2 5 7 A l p e r ,H . , 7 2 , 8 2 , 2 5 2 Af-Sader,B. H.,326 Alvarez,R. M., 339, 340 A m e m i y aM , .,73 4mer,I.,72,252 Amici, R., 253 Anderson,P. C., 316 Andersson, P. G.,245 Ando, K., 138 Ando, T., 1,97,287 A n d r e w sM , . A.,90 A n g e l l ,E . C . , 1 9 9 A n g l e ,S . R . , 3 6 9 Antel, J., 159 Antonietta,M., 155

AntoniolettR i, .,172 Aoki, O., 366 Aoyama, T., 344 A p p e l m a nE, . H . , 7 6 Araki, Y., 65 Arase,A., 130 A r e s ,J . J . , 2 1 5 Armacost,L. M.,54 Arnold, H., 161 A r n o l d ,L . D . , 2 3 Asaoka,M., 89 Asensio,G., 38, 39 Ashmawy,M. I. Al, 196 Askin, D., 85 Aso, Y., 19 Astrab,D. P., 201 A w a s t h iA , . K.,40, 177 Azzena,U ., 269 Baba,A., 306 Bachi,M. D., 330,332 B a c i o c c hEi ,. , 7 0 , 7 1 B a c k ,T . G . , 2 1 6 Biickvall,J .-E., 245 Baertschi,S. W., 143 Bagheri,V., 23t, 280 Bailey,B. R. (III), 323 Bakasse, M., 133 Baker,S. R., 33 Bakhmutov,V. 1.,24 Balci,M., 243 Balgobin,N., 217 Ballester,M., l3Z Ballester,P.,296 p.,99 Ballesteros, B a l l ,W . A . , 2 6 0 Ballini, R., 167, ti8 Bambal,R., 8 Bamfield,P., 250 B a n e r j e eA, . A . , 2 7 8 Banfi,L., 19 Banno,H., 205 Baranowska, E., 45 Barbaro,G.,207 Bargas,L. M., 113 373

374

Author Index

Barlos,K., 359 Barluenga, J., 38, 39, 64 B a r n u mC , .,58 Barrett,A. G. M., 21, 335 Barros,H. L. C.,295 B a r r y ,J . , 2 5 3 Biirtels,C., 88 B a r t m e s sJ ,. E . , 2 6 4 B a r t o n ,D . H . R . , 1 8 , 2 3 , 3 5 2 B a r t o n J, . C . , 2 2 4 Barua,N. C., 10 Basile,L. J., 76 Bates,T. F.,202 Batra,R., 174 Bats,J. W., 137 Batsanov,A. S., 24 Battaglia,A.,207 Bauer,G., 127 Bauld,N. L., 130 Bayer,C., 58 B e c k ,A . K . , 6 1 Beck, K. R. (Jr.), 144 Becker,D. A., 7 Bedoya-Zurita,M., 335 Beifuss,U., 159 Belikov,V. M.,24 M., 368 Bellassoued, Belmont,S. E., 132 B e l o k o nY , . N.,24 B e l o t t i ,D . , 3 2 3 Benigni,D. A., 33 Bennett,W. D.,340 Bergdahl,M., 62,229 Berglund,B., 175 B e r k ,S . C . , 2 2 5 , 2 3 0 Berrios,R., 1 Bertini,V., 170 B e r t z ,S . H . , 2 2 2 Betschart, C., 321 Bettinger,A., 352 Bey, P., 252 B. C. B., 2l Bezuidenhoudt, B h a t ,K . S . , 2 0 1 M. N., 57 Bhattacharjee, Bhushan,V., 11 B i g h a mM , . H.,202 Billhardt,U.-M., 137 Binger,P., 31 L.,284 Birckenbach, Birss,V. I., 216 Biswas,G., 109

Bittman,R.,342 B l a i r ,I . A . , 2 7 6 Block,E., 63 Blodgett,J. K.,257 Boardman,L. D.,231 B o a z ,N . W . , 2 2 6 B o d e n ,G . E . , 1 3 1 Bogdanovic,B., 194 Boger,D. L., 147,208,329 Bolitt, V., 353 Bonadies,F., 1'72,276 Bonini,C., 276 Boothe,R., 173 Boratynski,J.,291 Borchardt,R. T., 273 Bordwell,F. G.,264 Bos, M. E., 225 Bosch,E., 332 B o t t r i l l ,M . , 2 1 2 Boudin,A., 358 Boudjouk,P., 165 J., 314 Boukouvalas, B o u t i n ,R . H . , 2 5 7 B o y d ,D . R . , 1 4 3 B r a i s hT , . F.,210 B r a m ,G . , 2 5 3 B r a n c h a u dB,. P . , 5 Brand,M., 48 Brand,W. W.,356 Brandstatter,8.,127 Braun,M., 322 L. J., 11 Br€na-Valle, Breslow,R., 174 D. M., 166 Brestensky, Brocard,J., 188 Broka,C. A., 60 Brossi,A., 256 Brown,D. S., 238,239 Brown,H. C., 43, 85, 163,201,221 B r o w n ,J . D . , 2 2 2 Brown, M. P., 121 Brown, R. T., 105 B r o w n ,S . H . , 1 9 8 Browne,M. E., 300 Br{ickner,R., 165,209 B u c h ,M . , 1 Buchanan,G. L., 1 Buchwald,S. L., 80 Buckwald,S. L., 81 B u l y c h e vA, . G . , 2 4 B u n d ,J . , 2 6 0

Bundel,Y. G.,2E5 Bunnelle,W. H.. 7] Bunnett,J. F.,352 H.,358 Btirgier, Burgess,K., 34 Burkhart,J. P..251 Burkholder,C.R Burns,B., 248 B u r n s ,S . J . , 3 4 6 Buynak,J. D., 167 Byrne,N. 8., 170 B y u n ,H . - S . , 3 4 2

C a h i e zG , .,2Y Cai, D., 194 Cainelli,G., 18l Calet,S., 82 Camargo,W.,92 Cambie,R. C.. {7 C a m e r o nD, . W . . 5 C a m i c i L, . , 4 1 Campos,P. J., 3E.t C a m p sF, . , 2 1 6 Caple,R., 175 Capperucci,A.. 97. C a p u a n oL, . , 3 5 2 Carboni,8., 44 Carlier,P. R., ll0 Carlson,R., 319 Carnevale, G., 199 C a r o n ,M . , 1 1 0 Carpino,P., 66 Carrie,R., 44 Carrol, P. J., 2tl8 Cassidei, L., 212 Catalani,L. H.. 2{3 C a u b e r eP, . , 3 1 3 C a v a ,M . P . , l l l Cerveau,G., 358 C h a ,J . K . , 5 7 Chabardes, P.,316 Challener,C. A.. :: Chamberlin, A. R.. W.. !l Chamchaang, C h a n ,E . D . , 2 5 ' l Chan,M.-C., l8-1 C h a nN , ., lll Chan,T. H., 39. 55 Chang,H. S., 275 Chang,Y. H.. 155 Chao,J.-C.,26{

AuthorIndex Bundel,Y. G.,285 Bunnelle,W. H.,72 Bunnett,J. F., 352 Biirger,H., 358 Burgess,K., 34 Burkhart,J. P.,252 Burkholder,C. R., 320 Burns,B., 248 B u r n s ,S . J . , 3 4 6 B u y n a kJ, . D . , 1 6 7 Byrne,N. E., 170 Byun, H.-S.,342 Cahiez,G.,234 Cai, D., 194 Cainelli,G., 181 Calet,S., 82 Camargo,W.,92 C a m b i eR , . C.,47 C a m e r o nD, . W . , 2 6 8 C a m i c i L, . , 4 1 Campos,P. J., 38, 39 C a m p sF, . , 2 1 6 Caple,R., 175 C a p p e r u c cAi ,. , 9 7 , 2 2 6 C a p u a n oL, . , 3 5 2 Carboni,B., 44 Carlier,P. R., 110 Carlson,R., 319 Carnevale, G., 199 C a r o n ,M . , 1 1 0 Carpino,P., 66 Carrie,R., 44 C a r r o l ,P . J . , 2 4 8 Cassidei, L., 212 C a t a l a n iL, . H . , 2 4 3 C a u b e r eP, . , 3 1 3 C a v a ,M . P . , 1 1 2 Cerveau,G., 358 C h a ,J . K . , 5 7 Chabardes, P.,316 ChalleneC r,. A.,225 Chamberlin, A. R., 104 Chamchaang, W.,216 C h a n ,E . D . , 2 5 7 Chan,M.-C., 184 C h a n ,N . , l 1 l Chan,T. H., 39, 55 Chang,H. S., 275 Chang,Y. H., 155 Chao,J.-C.,264

Chapman,R. D., 14 Chastrette, F.,371 Chastrette, M.,371 Chatani,N., 118 Chatgilialoglu,C., 358,359 Chattopadhyaya, J., 217 Chaudhuri,M. K.,57 ChenC , .,323,325 C h e n ,H . G . , 2 3 3 Chen,J., 293 C h e n ,L . M . , 5 5 Chen,S.-F.,75 Chen,W., 112 ChenZ , .-C.,150 C h e n gC , .-W.,64 C h e n gJ, . - W , 3 0 1 Cheng,K.-M., 184 Cheng,W., 188 Cherest,M., 158 Chiba,M., 52-53, 179,180 C h i k a s h i t aH,. , 2 1 Chini,P., 334 Chittenden, G. J. F., 138 Chiu, F.-T.,155 Cho, F., 166 Cho, Y.-S.,166 C h o i ,Y . L . , 6 Chong,J. M., 350 Choukroun,R., 110 C h o y ,W . , 5 9 Christensen, D., 273 Chuit,C., 358 Citterio,A., 173 Ciufolini,M. A., 170,300 C l a r k ,J . H . , l 0 l Claxton,E. E., 280 Cldophax,J., 23 Clery, P., 234 C l i m e n tM , . J.,353 C l i v e ,D . L . J . , 3 1 6 , 3 2 4 Colin,S., 158 C o l l ,J . , 2 1 6 Collin,J., 283 Combrink,K. D., 321 C o m i n sD , . L.,222 Commeyras, A.,295 Conaway,R., 173 C o n c e p c i 6 Jn., I . , 2 5 8 Cooley,J. H., 83 Corbin,D. R., 367 C o r e y ,E . J . , 6 6 , 2 2 6

Y6

Author lndex

C o r k ,D . G . , 2 8 7 CorleY,E', 73 Corn6lis,A.' 101 Correia,C. R. D'' 131 Corriu,R. J. P.' 358 Corriveau,J.' 165 Cossy,J., 323 Costa,A., 296 Costero,A.,162 C o t a ,D . J . , 3 3 9 Coutts,I. G. C',25'l CowleY,A }J^',227 Coxon,J. M'' 309 Crabtree,R. H', 36' 198 Crabtree,S' R'' 206 P., 154 Cresson, C r i l l e YM , . M.,29 Crombie,L., 282 C r o u t ,D ' H . G ' , 2 7 4 C r o w ,R . , 2 2 8 Cuadrado'A' M'' 55 Curci,R., 212 Curran,D. P., 264,283' 326

Dupon.J Dupuy, C Durner. ( Durst, H. Dyer, U.

Eaton, D Eaton,J. Eaton. P Ebata,T Ebert. G Ebihara Eddy, F. Edgetl.\ Edwards Egert. E Ehrenka Eichhon Einhorn Eisch.J Elgend; Elisseou Elissott Ellenba Ellenbc Elliott. Elliott. Elliott. Ellis. K Ellswor Elmorc El-She Emzian Enders Endo, Engel. Engler Englist Enomc Entez: EPa.I Epifan Erdbri Erdeh Erker Ernsl. Esaki Eswa Evain Evans

Author Index

D u p o n ,J . W . , 2 7 0 D u p u y ,C . , 3 6 7 Durner, G., 137 D u r s t ,H . D . , 2 1 9 Dyer, U. C., 96

I

l'

i..

]{

6

i,\

:._ !., t-

.-:

t.: il{r. 326

I it

t'i-

,\ l\

l

1.,

Eaton,D. F., 107,367 Eaton,J. T., 300 Eaton,p. E., 144 EbataT , .,24g E b e r t ,G . W . , 9 9 E b i h a r aK, . , 2 l g E d d y ,F . D . , t l Edgell,W. F.,334 Edwards,M.,216 Egert,E., 45,242 Ehrenkaufer, R. E., 13, 14 Eichhorn,M., 137 Einhorn,J., lg3 Eisch,J. J., 185 E l g e n d yS, . , 2 5 7 Elisseou, E. M., 194 Elissondo, B., 237 Ellenberger, S. R., 200 Ellenberger,W. p., 200 Elliott,J., 291 Elliott,J. D., 52 E l l i o t t ,R . L . , 2 8 3 Ellis,K. L., 238 E l l s w o r t hE, . L . , 2 2 1 Elmore,p. R., 293 El-Shenawy, H. A., 311 Emziane,M., 16,342 E n d e r sD , ., 11 E n d o ,T . , 2 0 4 , 3 0 5 E n g e l ,M . , 3 5 2 E n g l e rT , . A,,321 English,A. D., 128 Enomoto,S., 166 Entezari-Moghadam, M., lg Epa, W. R., 177 Epifanio,R. de A., 92 Erdbriigger,C. F., 45 Erdefmeier,1., 122,260 Erker, G., 29g E r n s t ,T . D . , 1 7 , 4 2 EsakiT , .,26 Eswarakrishnan, V.,63 Evain,E. J., g3 Evans,D. A., 91

Evans,J. M., 301 E v a n sR , . D.,29 Faggi,C.,226 Fainzilberg, A. A.,76 Falck,J. R., 353 Faflaniis,F. J., 64 Fang,Q., 80 Farahi,J. 8., 79 Farina,V., 33 Faron,K. L., 95 Farooq,O.,292 Farwaha,R., 7 F a u q ,A . H . , 2 0 1 F e d o r o v aE, . 8 . , 2 4 Fehr,C., 154 Fenude,8.,269 Ferrier, R. J ., Z4g Fetizon,M., 149 Feutritl,c. I., 268 Fevig,T. L., 283 Fiandanese, V., 122,255 Figuly,G. D., 63 F i n e t ,J . - p . ,1 8 , 3 5 2 F i n n ,M . G . , 2 4 0 Fiorentino,M., 212 Firouzabadi, H., lg Fischer,E. O., 110 F i s h ,R . H . , 2 7 0 Fishpaugh, J. R.,227 Fitzsimmons, B. J., 111 Fleming,S. A., 147 F l i p p i nL , . A.,44 F l o y d ,C . D . , 2 6 3 Fobker,R., 134 F o c h i ,G . , 1 1 0 F o l a n d L, . D . , 2 9 6 F o l e y ,M . A . , 2 2 2 Fontana,F., 173 Ford,M. J., 105 Foubelo,F.,64 Fraile,A. G., 339 Francisco, C. G., l5l, 25g Fraser-Reid, 8., 50, 251 Frazier,R. H. (Jr.), l5g Frecherte,R., 253 Freire,R., 151,25g F r e y e rA, . 1 . , 2 9 7 Friedman,L., 347 Fringuelli,F.,356 F u ,G . C . , 9 1

3n

Author Index

Gaetano,K', 173 G a i s ,H . - J ' , 1 2 2 , 2 6 0 Gakh, A. A.' 76 Galindo,J., 154 Gallagher,D. W., 44 Gallucci,J' C.' 288 G a m i e a nA, . , 2 9 1 Gandhi,R. P.' 355 Gao, Y., 105,290' 308 Garcia,H., 353 A.,296 Garcia-Raso' Gardette,M., 122'158 Garegg,P. J.' 210 J. R., 234 Gasdaska, G a s e tA , ',84 Gassman,P. G.' 346 Gatos,D., 359 Gaudemar,M.' 368 Gaus,P. L', 295 Gauthier,J. Y.' 307 G e n e t ,J . P ' , 3 5 , 1 7 1 Gerdes,P., 11 G e r l a c hH, . , 6 7 , 3 4 4 Gernon,M.' 63 G6ro, S. D', 23 F, 152 Gdrritte-Voegelein, Gerritz, S. W., 295

Gervais,D., 110 Gervais,S., 291 Ghelfi,F.,146 Ghrlbi,A.,222 Giacomini,D.' 181 Giannis,A'' 186 Giese,B., 32'1' 359 Gilabert,D. M.' 175 Gilbert,J. C.' 191 Gilbertson,S. R.' 225 G i l d a YJ, . P . , 2 0 8 ,2 7 1 , 2 8 8 Gilges,S., 327 Giner,J.-L.' 267 G i n g r a sM , .,39'76 Giolando,D. M.,227 Giordano,G.' 334 Giorgianni,P., 207 Giumanini'A. G'' 13 J ., , 1 3 7 Glenneberg GodfreY,A.,227 G o k Y u ,K . , 2 2 1 Golding,8.T.,29 Golebeva,G. A'' 285 Gonzillez,A. M" 55 Gonzalez,F., 200 J' M.' 38' 39 Gonzalez, Goodman,B. A'' 231 Goralski,C. T.' 43 Goto, M., 190 Gottlieb,L.' 27 Goudgaon,N. M'' 343 Goulaouic,P., 149 Grandi,R.' 146 GraY,D.' 173 Green,A. E.' 152 Green,D' L. C',262 G r e e n ,M . , 2 1 2 N', 151 GreensPoon, Greiner,A., 357 Gribble, G. W.' 300 Griesbeck'A., 322 Griffiths,P. G.' 268 G r i g g ,R . , 9 1 ' 2 4 8 Griller,D.' 358 Grisoni,S., 35 Groneberg.R D" 248 Groninger,K' S'' 327 Guanti,G.' 19 Gu6nard,D.' 152 Guerrero,A.F,102 GuY, A.' 125' 126

H a ,D . S . , 9 3 Habaue,S., 239 H a l l ,D . , 2 9 1 Halfberg,A.,247 L. E.. l&< Hallenbeck, Halterman,R. L.. 138 Hamaguchi,F., 157 Hamasaki,T., 329 H a m d o u c hC i,.,2ll H a m l i n ,K . E . , 2 7 1 Han, D. I., 102 Han, K. I., 185 H a n a c kM , .,339 Hanamoto,T., 144 Handa,Y.,284 Hiiner,R., 113 Hanna,I., 149 Hannon,F. 1.,226 Hansen,M. M., l2 Hantzsch,A., 1l Hara, D., 239 Hara, S., 49 Harada,T., 239 Haraguchi,K., 289 Harding,M. M., 12l Harirchian,B., 130 Harlow,R. L., 158 Harmata,M., 4 H a r p p ,D . N . , 7 6 Harrington,R. E.. 57 Harris,T. M., 143 H a r t .D . J . , 3 2 9 Hartsough,D.,3m Harvey,R. G., 125.319 E., 129 Hasegawa, Hasemann,L., 243 Hashimoto,H.,29, 119 Hashimoto,M.,298 Hass,H. B., 335 Hasseberg,H.-A.. 3'f{ Hassner,A., 78 Hatanaka,Y.,221, bl HatjiaraPoglou,L.. As9 Hatsuya,S., 342 Hattori,A., 118 Hattori,K., l'72,239 Hattori,M., 52-53 Haugen,R. D., 316 Hauser,F. M., 200 Hayakawa,H., 289 Hayakawa,S., 103

AuthorIndex Ha,D. S.,93 H a b a u eS , .,239 H a l l ,D . , 2 9 1 Hallberg,4.,247 Hallenbeck, L. E., 185 Halterman,R. L., 138 Hamaguchi,F., 157 Hamasaki,T., 329 H a m d o u c hC i,.,211 H a m l i n ,K . 8 . , 2 7 1 Han, D. I., 102 Han, K. L, 185 H a n a c kM , .,339 Hanamoto,T., 144 Handa,Y.,284 Hiiner,R., 113 Hanna,I., 149 Hannon,F. J.,226 Hansen,M. M., 12 Hantzsch,A., 11 H a r a ,D . , 2 3 9 Hara, S., 49 Harcda,T.,239 Haraguchi,K., 289 Harding,M. M., 121 Harirchian,8., 130 Harlow,R. L., 158 H a r m a t aM , .,4 H a r p p ,D . N . , 7 6 Harrington,R. E., 57 Harris,T. M., 143 Hart. D. J., 329 Hartsough,D., 300 Harvey,R. G., 125,319 Hasegawa, 8.,129 Hasemann, L., 243 H a s h i m o t oH, . , 2 9 , 3 4 9 Hashimoto,M.,298 Hass,H. B., 335 Hasseberg, H.-A., 344 Hassner,A., 78 Hatanaka,Y. , 221, 364 Hatjiarapoglou , L., 259 Hatsuya,S., 342 Hattori,A., 118 Hattori,K., 172,239 Hattori,M.,52-53 H a u g e nR , . D.,316 Hauser,F. M., 200 Hayakawa,H., 289 Hayakawa,S., 103

Hayasaka,T., 219 H a y a s h iH, . , 1 5 7 , 3 4 0 Hayashi,M., 3f0 Hayashi,T., 127 Hayashida, H., 341 Hayata, T. , 347 Hayes,T. K., 128 H e a t h c o c kC, . H . , 1 2 Heerze,L. D., 316 H e g e d u sL,. S . , 9 3 , 9 4 Heikkilii,J., 217 H e i m ,N . , 1 3 7 Heitz,M.-P.,352 Hellmann,G.,260 Helmchen,G., 154 Helquist,P.,117,133 Hengge,E., 127 Henien,T., 307 Henke,S., 88 H e r b s tR , .,242 Hern6ndez,R., 258 Higashiura, S., 355 Hino, T., 40, 75 Hirama,M., 181 Hirano,M.,292 Hirao, A., 168 Hirashima,T., 297 Hirota, S., 265 H i r s t ,G . C . , 2 1 0 H i r u m a ,K . , 3 4 9 H i t r a ,K . , 9 6 H i y a m aT , . , 1 4 4 , 1 6 8 3, 5 5 ,3 6 4 Ho,E.,75 Ho, K. M., 184 Hoashi,K.,263 H o c k ,R . , 2 9 8 Hoekstra,W., 156 Hofer, O., 7 H o f m a n nK , . A.,88 Hofstraat,R. G., 139 H o g a n ,K . T . , 2 3 6 H o l l ,P . , 2 1 7 Holmes,A., 32 Homma,K., 14 Hon, M.-Y., 108 H o n d a ,T . , 2 8 Hopp, P., 217 H o p p e ,D . , 4 5 , 2 4 2 Hoppe,1.,242 H o p p e ,M . , 2 8 8 Horak, V., 113

3E0

AuthorIndex

Hori, H., 311 Hori, K., 113 Hori, Y., 107 Horiguchi,Y., 323 Horiuchi,C. A.,70,173 Hoshi,M., 130 Hoshino,M.,115,294 Hoshino,Y.,42, 136 Hosomi, A., 8, 219, 263, 305,318,337,341 Hosoya,K.,262 Hou, Y. Q.,293 Hot,2.,366 H o v e y d aA, . H . , 9 1 Hu, C.-J.,197 Hu, N. S.,19 Huang,H.-W., 197 Huang,X., 293,298 Huang,Y.-2., 169,242, 323,325,350 H u b b a r dS , .A.,254 Huber,F.,306 H u c h ,V . , 3 5 2 Hudlicky, T., 108 Huh,K.-T.,280 H u l c e ,M . , 2 2 3 Hungate,R., 116 Hurd, T., 167 Huseland,D. E., 166 Husinec,S., 132 Hutchins,R. O., 194 H u y e r ,G . , 2 3 Huyser,E. S., 128 Hwu, J. R., 164 H y o d o ,N . , 1 1 2 H y u g a ,S . , 4 9 Iavarone,C., 199 I b o r r a ,S . , 3 5 3 Ichihara,Y., 219 Ihara, M., 89, 260 I h l e ,N . C . , 1 3 1 Iio, H.,345 Ikeda,S., 145 Ikeda,T., 118 Imada,M., 306 I m a d a ,Y . , 2 4 7 , 3 5 5 Imagire,J. S., 101 lmai, K.,262 Imai, Y., 269 I m a m o t oT, . , 2 2 7 , 2 6 5 Imanaka,T., 56,216 Imaoka,M., 193

Imbert,D.,125 Imperiali,B., 34 I n a b a ,M . , 2 4 5 , 3 0 5 I n a n a g aJ,. , 2 8 4 lnazu, T.,73, 1.45 I n e n a g aM, . , 1 7 6 Ingham,S., 231 Inoue, M., 166,203 Inoue, T., 100 Inouye,M., 259 I q b a l J, . , 5 1 , 9 7 , 9 8 Ishar,M. P. S., 355 I s h i b a b aM, . , 2 l Ishida,E., 73 I s h i i ,M . , 3 4 5 Ishii,Y., 32, 120 I s h i k a w aM, . , 1 2 2 , 3 0 5 Ishiyama,T., 122 Ito, K., 168 Ito, S.I., 181 Ito, Y. , 127, 135, 163, 259 I t o h ,I . , 2 0 1 , 2 0 6 Itoh, K., 21, 29 I t o h ,T . , 6 5 , 1 3 6 Itsuno,S., 168 Iuel, s. D., 128 Iwahara,T., 364 I w a m o t oK , .,78 Iwamoto,Y.,344 Iwanaga,K., 2 I w a o k aM , .,29 Iwasaki,H., 54 Iwasawa,N., 103,241,313 Izumi, T., 246 Izumi,Y., 178,213,334 Jabri,N., 122 Jachiet,D., 223 Jackson,W. R., 69 Jacobi,P. A., 54, 98 E. N., 240 Jacobsen, J a d h a vP, . K . , 2 0 1 Jaggi,D., 314 Jain,N., 274 Jalali-Araghi,K., 44 J a m e sT, . D . , 1 0 2 Jammot,J., 295 A.,239 Janagisawa, Jarglis,P.,48 J., 43 Jasiczak, Jastorff,B., 308

Jastrzebsk Jedlinski.i Jeffery,T.. Jefford,C. Jefries, P. Jego,J. M Jennirtgs.I Jeon,Y. T Jesson,J. I Jin, Y.-Y.. Johnson.C Johnson.I Jones,C. I Jones,R. I Jones,T. I Jorgensen Josey,J. A Joshi,N. I J u g e ,S . , l ' Jung,M. E Jur5i6,8. Just,G., Z

Kabalka,C Kabat,M. Kadota,1. Kagan,H. Kageyama Kahn,M. I Kaiser,E. K a j i ,A . . I Kajigaesh Kajitani, tr Kakimoto. Kakinami Kakui, T.. Kalitsis,I.. Kambe, N. Kametani Kameyam Kamigata,I Kamimura Kamiyama Kanatani.I Kane,G. A Kaneda,K. Kaneko,T. Kan, T., 29 K a n ,Y . , 3 O Kang,K. K Kappes,D.

AuthorIndex Jastrzebski, J. T. B. H.,370 Jedlinski,2.,270 Ietrery,T.,173 Jefford,C. W.,314 Jeffries,P. M., 295 Jego,J. M., 44 Jennings, W. 8., 143 Jeon,Y. T., 129 Jesson, J. P., 128 Jin, Y.-Y., 150 J o h n s o nC, . R . , 2 6 5 , 2 8 8 Johnson,W. S., 52 Jones,C. W., 101 J o n e sR , . A.,227 Jones,T. K., 85 Jorgensen, K. A.,2i3 J o s e yJ, . A . , 2 5 6 Joshi,N. N., 163 Juge,S., 171 Jung,M. 8., 236 Jur5i6,8.,77,78,253 Just,G., 258 Kabalka,G. W., 173,343 K a b a t ,M . M . , 3 2 8 K a d o t aI,. , 3 3 8 K a g a nH , . 8.,268,283 Kageyama,H., 185 Kahn,M. A., 97 Kaiser,E. M., 288 Kaji, A., 59,219,262 Kajigaeshi, S., 25 Kajitani,M.,340 Kakimoto,M.,269 Kakinami,T.,25 Kakui, T., 364 Kalitsis,I., 359 KambeN , .,297 Kametani,T.,28,260 Kameyama, M., l8 Kamigata,N., 18,218 Kamimura,A., 219, 289, 328 Kamiyama,T., 166 Kanatani,R., 364 Kane,G. A. O., 143 K a n e d aK, . , 2 1 6 Kaneko,T., 268 Kan, T., 298 Kan, Y., 305 Kang,K. K., 89 Kappes,D., 67

Karabelas,K., 247 K a r a d yS , .,73 K a r l s s o nJ,. O . , 2 9 6 Kasahara, A.,246 Kasai,S., 310 K a t o ,K . , 3 4 0 Kato, R., 221 K a t o ,T . , 2 4 1 Katogi,M., 89 Karsuki,M., 119 Kauffmann,T., 134 Kawabata,A.,84 Kawada,K., 160 Kawai,M., 178,213 Kawasaki,Y., 118 Kawase,M.,273 Kawashima, M.,224 Kaye,A., 86 Keck,G. E., 131 Keinan,E., 15l Kellermann, K.,284 Kelly,T. A., 191 K e l s o nA , . B.,52 K e m m i t tD , . W.,8 Kerr, J. M., 250 Kezar,H. S., 58 Khamsi,J., 352 K h a n ,M . A . , 5 1 , 9 8 ,1 1 7 K h e t a n iV, . D . , 2 1 2 Kibayashi, C., 193 K i j i ,s . , 7 0 KikuchiK , .,257 K i k u k a w aK, . , 6 9 Kilian,W. J., 358 Kim, B. M., 105 K i m ,D . , 3 2 6 Kim, H., 102 Kim, H. S.,236 Kim, J. C., 275 Kim, K. S.,275 Kirn, M.-W., 126 K i m , S . , 1 5 0 ,1 5 2 , 2 6 5 , 3 4 8 K i m ,S . J . , 5 7 Kim, Y. H.,218,275 Kim,Y. 1.,275 Kimura,T., 197,287 Kimura,Y.,272 Kin,Y. H.,275 King, A. O., 73 King, S. M., 80 K i n o ,Y . , 3 2

3E2

AuthorIndex

Kipphardt,H., 11 Kira, M., 40, 75 Kirino, K., 359 Kirio, Y., 245 Kirst, H. A.,31'7 Kishi,Y.,96, 186 Kit^,y.,25'l Kitamura,T., 6 Kiyoi, T., 30 Klaeren,S. A.' 90 Klair, S. S., 121 K l e i j n ,H . , 3 7 0 Klein, K.-D., 184 Klein, R. F. X.' 113 Klingler, F. D ., 4'7 Kloker,W., 261 Knochel,P., 225,230,232,233 Ko, Y. K., 152 Kobara,S., 203 Kobayashi,K.' 156 M.' 280 Kobayashi, foUayastri,S., 15,310,315,360' 361'362 T.' 114 KobaYashi, Kobayashi,Y.' 326 Koerner,M.,228 Koga,K.' 166'182 Koga,T., 152 Kohli, T.-P., 368 K o h m o t oS , . , 6 1 '3 1 0 Kohra, S., 263, 305,337' 341 Koizumi,T., 3 Kolasa,T., 352 Kollmann,G.' 12'7 Kondo,H., 153 Kong,F., 293 P.,50 Konradsson, Konstantinidis,D., 38 Kopping,B'' 359 Koreeda,M., 9 KornetzkY,D.' 190 Koroniak, H.' 326 R.' 368 KoschinskY, Kosugi,M',124 Korsuki,H., 338' 367 Kowalczuk,M.' 270 Kozikowski,A. P.' 148 K o z ' m i nA , . S.'76.175 Krafft,G. A.,284 Kriimer, T., 45 Krause,N', 7 Kravitz,J. I.' 54' 98

Kreider,E. M.' 356 Krimen,L. I.' 339 Krishnamurti'R., 341 Krishna,M. V.' 216 Kruse,L. I., 247 Krysan,D. J.' 31 Kubas,R., 262 K u b o t aY , .,40 Kudou,N., 246 Kuhara,M., 185 Kulawiec,R. J.' 36 Kumada,M.' 305'364 Kumazawa,T.,27l Kiindig, E. P.' 16 Kunishima,M.' 176 Kunita,K., 303 K u n n g ,F . - A . , 9 4 Kunz,H., 103'307 Kurosawa,H.' 118 Kurusu,Y., 309 K u r z ,K . G . ' 3 1 1 Kusumoto,T., 221 Kuwajima,I.,323 F-'' 217 Kuyl-YeheskielY, Kwarst,8., 64 K w e t k a tK , .,42 Kyler,K. S.' 146 Labiad,B.' 214 Laborde,E.,2'72 Lal, G. Sankar,41 Lal,S. G., 218 Lamberth,C., 327 Landolt,R. G.' 293 L a n e ,J . F . , 2 5 7 Lang,R. W.' 68 Lange,J', 139 Laosalle,G.' 158 Larock,R. C.' 246 Larsen,S. D., 134 Larson,G. L.' 1 Larson,S., 173 Lasarte,J., 304 LasleY,L. C., 196 Laszlo,P., 101 Laube,T., 113 Laucher,D.,230 Lavall6e,J.-F.,58,74 Lavergne,O.' 288 Lawrence,R.' 126 Leblanc,Y., 111

Lecolier.! Lee, D. C L e e ,H . . I Lee, H. K L e e ,J . , 3 L e e ,J . G . L e e ,J . I . . L e e ,K . . l Lee, P. H Lee, S.. 2 Lee, S. rl Lee, T. A Lee, T. J Lee, T. ! Lee, Y.. I Leeds.J. Lefeber. LeGaffe. Leged2.! Lemaire Lemor. y Leon, P. L€onard Lesage.I Lesage.! Lewis,C Lewis.N Ley, S. \ Lhoste.I

Li, s.-w

Liang. Y Liao, Q. Liaw, B. Lichtent Lidor. R Liebesk Lin, L. ( Lin, R.. Linderm Lindsay Lindstcd Lindstro Liotta. I Lippsmc Lipshuu Liu, H.Liu, H. Liu, K.Liu, T.. Llebaria Lloyd. I

AuthorIndex L e c o l i e rS, . , 1 2 4 , 3 1 3 Lee, D. C., 108,354 Lee, H., 125 L e e ,H . K . , 2 7 5 L e e ,J . , 3 6 3 Lee, J. G., 89, 93 L e e ,J . I . , 1 5 2 Lee, K., 320 L e e ,P . H . , 1 5 0 , 3 4 8 Lee, S., 231 L e e ,S . W , 2 4 1 L e e ,T . A . , 1 5 0 L e e , T .J . , 2 6 3 Lee,T.Y.,72,238 L e e ,Y . , 5 4 L e e d sJ, . P . , 3 1 7 Lefeber,A. W. M., 217 LeGaffe,F.,294 LegedZ,5.,277 L e m a i r eM , .,125,126 Lemor,A., 125,126 Leon,P.,360 L6,onard,E.,282 Lesage,M., 358 L e s a g eS, . , 2 0 0 LewisC , . N.,263 Lewis,N., l0 Ley, S. V., 238,239 Lhoste,P., 16,342 Li, s.-w.,242 Liang, Y., 343 Liao, Q., 351 Liaw, B. R., 164 Lichtenthaler,F. W., 47, 48 L i d o r ,R . , 4 8 Liebeskind, L. 5.,234 Lin,L. C.,164 Lin, R.,283 L i n d e r m a nR, . J . , 2 2 7 Lindsay,C. M., 63 Lindstedt,E.-L.,229 Lindstrom,P. A. (Jr.), 168 Liotta,D., 58, 156 Lippsmeier, B., 114 Lipshutz,B. H., 221, 224, 228 Liu, H.-J., 146,255 Liu, H. T.,326 Liu, K.-T., 197 Liu, T., 283 Llebaria,A., 216 Lloyd, D.,268

Lo, L.,307 Loewenthal, H. J. 8.,27 Logusch,E. W., 319 Loh, T.-P.,4, 142 L o n g ,J . K . , 2 7 2 L o o p ,C . K . , 6 3 Lopez,L.,272 Lorenz,K., 48 L o u d o nG , . M.,257 Lu, X., 135 L u b e l l ,W D . , 4 9 Lucchesini,F., 170 Lucchini,V., 322 Luche,J.-L., 183 Luche,J. L., 367 L u e n g oJ, . I . , 9 , 3 5 3 L u e o e n dR, . , 2 1 5 Luh, T.-Y., 184,343 Luidhardt,T., 173 Luo, F.-T.,301 Lusinchi,X., 158 Lutomski,K. A.,230 L y s o v aL, . 4 . , 2 4 Ma, D., 135 M a a s ,G . , 1 8 1 M c C a l l u mJ, . 5 . , 9 4 , 2 3 4 McGettigan, C., 166 M c G o r a nE , . C.,294 McGuckin,R. M., 143 M a c h a d oA, . S . , 2 3 Maciejewski,L., 188 M c K e n z i eJ,. R . , 2 2 1 Mackenzie, P. B., 3l McLoughlin,J. I., 2 M c M u r r y ,I . E . , 3 1 7 , 3 5 7 M c N a b ,H . , 2 6 8 McParland,M.,257 Madesclaire,M., 166 Maeda,K., 135 M a e n o ,K . , 2 5 Maercker,A., 184 M a e t a ,H . , l 2 l Magee,J. W., 29 Maginn,R. E., 132 Maginn,S. J., 121 Mahidol,C., 162 M a i t i ,S . N . , 2 8 4 M a j e w s k iM , .,316 Makabe,Y.,303 Makinouchi,S., 152

3S4

AuthorIndex

Mal, D., 109 Malekzadeh,M. N.' 6 Mallart,S., 171 M a m o sP , .,359 ManastyrskYj,S., 132 Mandai,T., 249 M a n d e r L, . N . , 2 0 6 Mangatal,L., 152 Mangeney,P.,222 Manickum,T., 109 M a n n ,C . M . , 2 3 6 M a n t l o ,N . 8 . , 2 5 2 Manzer,L. E., 81 ' 178 Marcantoni,8., 16'7 G.,122,255 Marchese, Marcinow,2.,28 Margot, C., 267 Mariano, P. E., 129 Mariano,P. S., 75 Marino, J. P., 126,272 Markd, I., 240 Martello,G., 181 Martin,J. C., 63 Martin, M., 188 M a r t i n ,O . R . , 3 1 1 M a r t i n ,R . , 3 1 9 M a r t i n , 5 . F . , 2 2 ''12 5 6 Martin,V. A', 189 Martinelli,M' J.' 54 Martinengo,S., 334 Martinez,A. G.,339 M a r t o n ,D . , 6 5 Maruoka, K., 42, 65, 136,140-141'204' 205,221 S., 9 Masamune, Mascaretti,O. A.' 39 Masnyk,M., 328 Masuda,H., 168 Masuda,Y., 130 Masumi,F., 182 Masuyama,Y., 309 M a t a ,E . G . , 3 9 Mathvink,R. J., 329 Matsuda,H.,306 Matsuda,L, 334 Matsuda,T., 69 Matsuda,Y.,268 Matsui,S., 362 Matsumoto,T.,119' 121 Matsumoto,Y., 127 Matsuoka,Y., 341

Matsuyama,H., 18 N.,40 Matsuyama, Matsuzawa,S., 323 Mattay,J., 181 Mattson,M. N., 117 M a y n a r dG , . D.,288 Maynard,S. C., 195 M a y r ,H . , 3 6 8 Medina,J. C., 146 Meguro,H., 311 Meier,I. K., 364 Meier, M. S., 5 Meinke,P. T',284 M e l l o ,R . , 2 1 2 Melloni,G.,269 Mellor,J. M., 197 M e l n i c kM , . J.,297 Menezes,R., 337 Mertes,J., 181 Mestres,R., 296 Meth-Cohn,O., 187 Metschies,T., 308 Meyers,A. 1., 147,230 Meyers,H. V., 95 Micetich,R. G., 285 Michael,J. P., 261 M' J.' 231 Micha-Screttas, Middleton,D. S., 178 M i d l a n dM , . M.,2 Migita,T., 33, 124 M i h e l i c h8, . D . , 3 2 2 MikamiK , .,4,27'142 M.,277 Miko{ajczYk, M i l l e r ,D . B . ( J r . ) , 9 3 Miller, J. M., 101 Miller, M. J., 352 Miller, M. L., I Mills, S. G., 85, 338 Minami,K., 59 M i n a m i ,T . , 4 6 , 2 6 5 Minamikawa,H.' 103 M i n g ,H . H ' , 6 2 Minisci,F., 173 Minuti, L., 356 Mioskowski,C.. 352'353 Miranda,M. A.' 353 Misiolek,A.,270 Mita,T.,221 Mitchell, T. N', 42 Mitsudo,T., 107 Mitsui,H.,295

Miura, Miwa. Miyarx Miyanc Miyasa Miyash Miyaur Miyazr Mizuno Mochiz Mochiz Mohal Mona! Monge Montai Moorc, Moore Moorn Mootq Mordir Moret( Moren Morga Mori. I Mori.' Moriar Morikr Morikl Morim Morim Moriu Moris Moriw Morlq Monq Moton Mouss Moyar Mtoct Mukai 3( Mukcr Mukh Miillct Miiller Mullcl Mural Mural Mural Murai Mural

AuthorIndex M i u r a ,M . , 2 9 , 1 1 8 M i w a ,Y . , 2 , 3 1 5 Miyamoto,S.,249 Miyane,T., 30 Miyasaka,T., 289 Miyashita,M.,294 M i y a u r aN , .,122 Miyazaki,K., 168 Miuno,T.,29l Mochizuki,A.,269 Mochizuki,H.,218 Mohajer,D., 18 Monaghan,A.,194 Monger,S. J., 289 Montaia, A. M., 117 Moore,C., 187 Moore,H. W.,296 M o o r m a n nA, . 8 . , 1 4 4 M o o t o o ,D . R . , 5 0 , 2 5 1 M o r d i n i ,A . , 6 2 M o r e r 6J, . M . , 2 1 6 Moretti,R.,229 Morgan,I., 10 M o r i .K . , t 3 5 Mori, Y., 185 Moriarty,R. M., 40, 176,1,77,323 Morikawa,S., 31 Morikawa,T.,326 Morimoto,K.,56 Morimoto, T., 52-53, 179,1g0,292 Morita, Y., 148 Moriwake,T.,245 Moriwaki,M.,25 Morley,C.,102 Morton,H. E.,350 Motorina,L A., 285 M o u s s aA, . , 3 3 6 Moyano,A.,270 Mtochowski,J., 190 M u k a i y a m a7,. , 1 4 , 1 5 , 1 9 33, 1 0 ,3 1 3 ,3 1 5 , 360, 361,362 M u k e s hD , .,278 Mukhopadhyay,T., 6l Miiller, P., 175 Miiller,S., 1l Mulley,S., 121 Murahashi, 5.,247,303 Murahashi,S.-I., 56, 295 Murahashi,S.-J.,355 Murai, S., 42, 118 Murakami,M.,259

Murata,S., 349 Murray, R. W., 144 Murthy, K. S. Keshava,316 Muzart,J., 57 Myers,A. G., 168 Myers,P. L.,263 Myles,D. C.,202 Nagai,Y., 32, 190 Nagao,Y., 176, 177 Nagasaka,T., 157 Nagase,T., 15, 22 Nagohara, Y.,265 Nakahama, S., 168 N a k a i ,E . , 6 1 Nakai, T., 4,27, 61.,142 Nakajima,H.,245 Nakajima,K., 190 Nakamura,E., 100,323 Nakamura,J., 340 N a k a m u r aY, . , 2 0 1 , 3 0 3 Nakanishi, T., l15 Nakano,M., 168 Nakano,7.,32, 120 Nakao,K., 172 Nakashima, H.,46 Nakata,T., 192 Nakayama, J., 115,336 Nalewajek,D., 160 Namiki,T., 3 Naneda,K., 56 Naota,T., 56 Narasaka, K., 103,241,313 Narayanan, B. A.,72 Narisano,E., 19 Naruse,Y.,26,251 Naruto,S., 113 Naso,F., 122,255 Nassimbeni, L., 140 Negishi,E., 1,23,231, 301,302 Neidle, S., 86 N e m e t hD , .,162 Neumann,W. L.,312 Ng, C. T., 184 Nguyen,T.,301 Ni, z.-J., 343 Nicholas,K. M., 117 Nicolaou,K. C., 248, 271 Nielsen,R. B.,80 Nilsson,M.,229 Nishida,A.,60

3t6

Author Index

Nishida,Y.,311 Nishigaki,S., 344 Nishiguchi,I., 297 Nishimura,K.,247 Nishio, T., 37 Nishizaki,I., 181 Nishizawa,M., 305 N i t t a ,Y . , 2 8 1 Nivard, R. J. F., 139 Niven,M., 140 Nokami,J., 249 NomuraM , .,29, 118 N o m u r aR , .,265 Nonoshita,K., 140-141,204' 205 Nordahl,A., 319 Normant,J. F., 122,222' 232 Noyori,R., 148,349 Nozaki, H., 84, 114,202,203 Nozaki,K., 333,337 N u g e n tW , A.,81 N u n n ,C . M . , 2 2 7 Nyangulu,J. M., 146 M., 355 Obayashi, Ochi, M., 338,367 Ochiai,M., l'76,177 O'Connor,8., 301,302 O'Connor,E. J., 117 O d a ,M . , 3 7 O ' D o n n e l lM , . J',340 Ofner,A., 353 Ofori-Okai,G.,63 K., 341 Ogasawara, Ogata,K., 263 Ogata,S., 269 O g a w aA , .,297 O g a w aH , .,249 O g a w aM , . , 3 2 , 1 2 0 '1 5 1 Ogawa,Y.,277 O g i s oA , .,334 Oguni,N., 207,268 O g u r a ,E . , 2 0 oh, D. Y., 102,320 Ohfune,Y.,1'13,274 Ohgo,Y.,277 O h k a t aK , .,54 Ohkawa,Y.,207 ohki, H.,37 O h l m e y e rM , . J.,34 Ohno, R., 178 O h r u i ,H . , 3 1 1

O h t a ,T . , 3 3 9 ohtsuki, M.,36 Ohwada,T., 339 oi, R., 72, 14s Oishi,T., 192 O k a ,S . ,1 5 6 Okabe,K., 339 O k a d a ,K . , 3 7 Okada,Y.,265 O k a m o t oK , .,37 O k a m o t oT, . , 2 5 , 1 5 6 Okazaki,H.,202 Oku,A.,239 Okuda,F.,280,359 Okukado,N., 152,303 O k u r o ,K . , 1 1 8 Olah, G. A., 17, 41,292,341 Olsson,T., 229 Onaka,M., 178,213 O n o ,M . , 2 0 1 , 2 0 6 Ono, N., 219,289,328 O o n ,S . - M . , 2 7 9 ootake, K.,262 Oppolzer,W., 68, 302' 335 O r i ,K . , 2 l Oshima,K.,333,337 Otera, J., 84, 114,202' 203 Otsubo,T., 20 Ousset,J.-8., 201 Overman,L. E., 161 Oyamada,H., 145 Ozaki,S., 15,22, 112 P a d w aA , .,278 Page,P. C. Bulman,121 Pagni,R. M., 173 Pagnoni,U. M., 146 Pak, C. S., 241 P a l i o ,G . , 6 2 Palkowitz,A. D., 138 P a l o m oC , .,304 P a n ,L . - R . ,3 1 8 P a n d eC , . S.,274 P a n d e yB, . , 3 4 6 Panek,J. S., 147 J., 45 Pankowski, P a n s a r eS,. V . , 2 3 Panunzio,M., 181 D.' 359 Papaioannou, Paquette,L. A., 158,208,271' 288 S. M., 38 Paraskevas,

P a r k ,J . H . . Park,P., l{ Parker,D. I Parry, D. M Parsons,P. J Pascal,-R.I Patel,M.. l. Patil,S.,]9( Pavlidis.V. Pavlov, V. y Pearson,A. Pederson.E Peet,N. P.. Peiseler.B.. Pellacani.L Pelter,A.. i Penmasta.I Pennington Pentaleri.! Pereyre.M. Periasamv Pericas,M, P6richon.J. Perlin,A. S Perlmutter Perri, S. T.. Pete,J. P.. Peters,E. I Peters,K.. Petit,A.. t' Petrier,C.. Petrini,M.. Pfordt,M.. Pfrengle.\* Phadke,A. P h a n ,A . . I Pho, H. Q. Picard,J. P Picci,N.. l' Piermattei Pierpoint.( Piers,E.. I Pike,G. A. Pinhas,A. Pinto,A. C Pittman,J. Pocci,M.. Pohmakot Poiana,M. Polniaszek Polt, R. L ,

AuthorIndex P a r k ,J . H . , 2 6 5 Park, P., 148 Parker,D. A.,229 Parry,D. M.,299 p. J.,210 Parsons, Pascal,R., 295 Patel,M., 147 Patil,S., 296 Pavlidis,V. H.,257 Pavlov,V. A.,24 Pearson, A. J.,212 P e d e r s o nE,. 8 . , 2 6 7 Peet,N. p., 252 Peiseler, 8.,209 Pellacani, L., 155 Pelter,A., 257 Penmasta, R., 40, 177 Pennington, L.,257 Pentaleri, M., 156 Pereyre,M.,237 P e r i a s a mM y ,. , 1 1 7 P e r i c a sM, . A . , 2 7 0 Pdrichon,J.,2g2 Perlin,A. S., 200 Perlmutter,p., 69 Perri, S. T., 296 Pete,J. p., 323 Peters,E. M., 154 Peters,K., 154 Petit, A., 253 Petrier,C., 367 Petrini,M., 167,l7g Pfordt, M., 352 Pfrengle,W., 103,307 Phadke,A. S., 85 Phan,A., 167 P h o ,H . e . , 2 7 9 Picard,J. p., 304 Picci,N., 170 Piermattei, A., 71 Pierpoint,C., 29 Piers,E., 228,350 P i k e ,G . A . , 2 5 9 P i n h a sA, . R . , 2 1 6 Pinto,A. C., 92 P i t t m a nJ, . H . , 2 g g Pocci,M., 170 Pohmakotr,M., 41 Poiana,M., 13 Polniaszek, R. p., 132 Polr,R. L., 64

Pons,J.-M., 315 P o r t e rA , . E. A.,132 Porter,J. R., 72 Potier,p, 152 Poupaert,J. H., 100 Poupart,M.-A., 15g Pourcelot,G., 154 P o w e r J, . M . , 2 2 7 Powers,D. B., 13g Prakash,C.,276 P r a k a s hG, . K . S . , 2 9 2 , 3 4 1 P r a k a s hL,, 4 0 , 3 2 3 Prakash,O.,323 Prasad,J. Siva,316 Prechtl,F.,243 Preut,H., 306 P r i e t o J, . A . , 1 Primo,J., 353 P r i t c h a r dG, . J . , 6 3 P u c h o rC, . , 2 6 g Puleo,R., 58 Pulido,F. J.,55 Purkayastha, S.,57 Purrington, S. T.,2gg Qian, C., 132 Qiu,A., 132 Q i u ,W . , 3 5 1 Q u e n d oA , .,317 Quiclet-Sire, B., 23 Q u i n k e r tG , .,137 Quintard,I .-p., 237 R a , C . S . ,2 i 1 , 2 8 8 Rabideau,p. W., 2g Radhakrishna, A. S., 257 Radics,L., 356 Radinov,R. N., 6g Rahm,A., 237 Rahman,A. F. F. M. M., 265 R a i ,K . M . L . , 7 8 R a i n b o wL, . J . , 2 9 2 RajanBabu,T. V, 8l Rakshit,D., 334 R a m ,S . , 1 3 ,1 4 Ramamurthy,V., 107, 367 Rambaud,M., 133 Ramesh,S., 329 R a n d ,C . L . , 2 3 1 Raney,K. D., 143 Rangaishenvi. M. V, 43, g5

3EE

Author Index

D., 149 Ranganathan, S.,149 Ranganathan, Rao, K. Rama, 107 Rao, S. P., 311 Rapoport,H., 49 Rassu,G., 269 Rathbone,D. L., 274 Ray, J. E., 321 R e a m e rR , . A.,85 Rebek, J. (Jr.), 162 Reddy, A. V. N., 285 Reddy,P. P., 1l Reddy,P. S. N., 1l Reed,R. T.,293 Reese,C. B., 86 R e e t zM , . T.,67,lll Reginato,G., 97 Rehwinkel,H.,260 Reichlin,D.,266 R e i d ,D . H . , 2 6 1 Rein,T., 133 Reye,C., 358 Reynolds,D. W., 130 R e y n o l d sM, . E . , 3 2 7 Rhee,C. K.,290 Ricart,G., 188 Ricca,D. J., 9 ,226 Ricci,A., 41,62,9'1 Richardson,K. A., 238 R i c o ,J . G . , 3 1 7 R i e k e ,R . D . , 9 9 , 2 2 9 Riley,E. F.,335 J ., 234 Rivas-Enterrios, Robarge,K. D., 208 Roberts,B. W.,99 Roberts,S. M., 289 R o b y r ,C . , 3 3 5 Roden,F. S.,72 Roder,H., 154 J.,156,207 Rodriguez, Rodriguez,M. A.,38 Roesky,H. W.,261 Rokach,J., 111 Romaniko,S. V.,77 Romine,J. L.,147 Ronzini,L., 122 Roos, G. H. P., 109 R o s e ,B . G . , 2 6 1 Rosemeyer,H., 357 Rosini,G., 167,178 Rotunno,D.,122

Rounds,W. D', 300 Roush,W. R., 138 G.,317 Rousseau, Rowley,E. G., 113 Roy, R., 291 Rozen,S., 48 Riichardt,C., 331 Ruggeri,R. 8., 12 Ruppert, I., 341 Ruppin, C., L24 Riither,R.,306 Rutledge,P. S., 47 Rutschow,D.,42 Ruzziconi,R', 70, 7l R y z h o vM , . G.,24 T., 30, 31 Saegusa, Sagawa,Y., 361 Sager,W, 103 Saha,C., 63 Saha-Moller,C. R.' 243 Said,H., 346 Saimoto,H., 151 S a i t o ,S . , 2 4 5 Saito,T., 145 Saito,Y.,310 Y.,340 Sakaguchi, Sakai,M., 359 M., 113 Sakaitani, Sakakibara,Y., 359 Sakatsume,O., 36 Sakurai,H., 75, 305'318 Salama,P., 165 J. A., 258 Salazar, Saleh,S., 276 Salomon,M., 146 Saltur,P. B., 107 Samii,Z. K. M. Abd El' 196 Samuel,O.,268 Sandhoff,K., 186 Sangsari,F. H., 371 Sanida,C., 359 Sano,H., 33, 124 Sano,T., 118 B. D.' 256 Santarsiero, Santelli,M., 315 Sapino,C. (Jr.), 33 Sarmah,P., 10 Sartori,P., l14 Sasai,H., 245 Sasaki,H., 122

Sasaki.! Sasaya. Sashiwa Sato,F. Sato,S. Sato,T. Satoh.J Satoh.I Satoh.T Savaria Savic.V Sawada Sawada Scettri. Schiifer Schanz Schaub Schectc Scheer Scheffo Schlech Schlich Schme Schmid Schmid Schmid Schmie Schmiu Schneid Schner Schobe Schone Schore Schrau Schreih Schultc Schulu Schulu Schusto Schwa Schwar Schwan Schwe Sciacov Scott.L Scretta Seqen.I Seconi Seebac Seela.I Seidlcr

AuthorIndex Sasaki,M., 283 Sasaya, J., 145 Sashiwa, H., 151 Sato,F., 166 S a t o ,S . , 2 0 1 , 3 3 4 Sato,T., 114,202, 203,221,224, 347 Satoh,J. Y., 173 Satoh,M., 122,124 Satoh,T., 18,78 S a v a r i a rS, . , 6 0 Savic,V., 132 S a w a d aH, . , 2 3 1 S a w a d aM, . , 5 9 Scettri,A., 172 Schiifer,B., 3l Schanzenback, D., 103 Schauble, J. H., j, 29 Schecter, H.,347 Scheeren, H. W., 139 Schefold,R.,365 Schlecht, M. F., 102 Schlich,K., 341 Schmeisser, M., 114 Schmidt,8., 321 Schmidt,J., 247 Schmidt,M., lt4 Schmiedl,G.,260 S c h m i t zA, . , 1 1 1 Schneider, U., 42 Schnering, H. G. V., 154 Schobert, R., 120 Schonenberger,B.,256 S c h o r eN, . E . , 1 1 3 Schrauzer, G. N., 156 Schreiber, S. L.,95 S c h u l t eG, . , l t 6 Schultz,A. G., 57 Schultz,C., 308 Schuster, G. 8., 129,300 S c h w a b eR, . , 2 9 6 Schwartz,J., 364 Schwarz, C., 137 Schweiger, E., 271 Sciacovelli, O.,212 S c o t tL , . T.,280 Screttas, C. G., 231 Segen,H., 243 S e c o n iG , ., 41,226 Seebach, D., 7, 51, 61, 113,321 S e e l aF, . , 3 5 7 S e i d l e rM , . D.,42

389

Seike,K., 22 Sekiya,K., 100 Sellers,S. F.,326 S e n e tJ, . P . , 3 1 3 Sercel,A. D., 74 Seri,T., 269 Serratosa, F.,270 S e t h iS , .P.,206 Seyferth,D.,231 S h a n k l i nM, . 5 . , 2 i 9 Shapley,P. A.,236 Sharpless, K. B., 105,110,240,290,308 S h a r pM , . J . , 1 6 1 ,1 8 8 Sheldrick,c. M., 159 S h e nT , .,60 Shen,W., 326 Shen,Y., 323,325,351 shi,L., 169,350 s h i , L . - L . ,2 4 2 Shibasaki, M., 245 Shibato,K.. 46 S h i d aN , ., 185 Shigemasa, Y., 151 Shigemoto, T., l8l s h i h ,M . - H . , 1 9 7 s h i h ,Y . , 3 1 7 S h i m aK , ., 89 Shimagaki, M., 192 Shimakawa, C., 145 Shimamoto, K., 271 S h i m i z uM , .,286 S h i m i z uS, . . 3 1 5 Shimobayashi, A., 359 S h i n ,D . - S . ,3 5 3 S h i n e rC, . S . , 6 4 , 2 3 1 S h i n k a Ii ., , 8 5 , 3 3 8 Shioiri,T., 344 Shiota,T., 295 Shirahama, H., 298 Shirai,H., 120 Shiraishi, H., 366 Shiraishi, K., 22 Shirasaka,T., 42, 65, 136 Shiro,M., 176 Short,R. P., 9 Showalter, H. D. H., 74 S h u d oK , .,339 S i a h a a nT,. J . , 2 2 1 Siddiqui,M. A., 189 Sidler,D. R., 235 Sierra,M. A., 94

390

Author Index

Silveira,A. (Jr.), 301 Simmons,D. P., 16,266 Simpkins,N. S., 178 Singaram,8., 43, 201,221 Singh,G. P., 149 Singh,M., 144 Singh,M. P.,284 Singh,R., 258 A. K.,273 Sinhababu, Sinou,D., 16,342 Sivakumar,R., 194 Skupsch,J., 260 Skuy, D., 266 Smith,C. S., 121 S m i t h ,K . , 6 3 S m i t hM , .8.,337 Snieckus,V., 188,189 Snyder,J. K.,363 S o ,J . - H . ,1 6 5 Soai,K., 219 Sodeoka,M.,245 S o e ,H . M . , 2 6 7 Solladid,G.,211 R. F.,47 Somerville, S o n o d aN, . , 4 2 , 1 1 8 , 2 9 7 Sotiriou,P., 359 Speirs,R. A.,261 Spevak,P., 284 Spicer,L. D., 13 Spilling,C. D., 335 S p r i n g e rJ,. P . , 1 1 1 Spunta,G., l8l Srebnik,M., 163 Sridar,V., 331 Sridharan,V., 248 R. G., 18 Srivastava, Srivastava,R. R., 98 Staab,E.,322 Stafiord,J. A., 357 S t a n gP , .J . , 6 Steel,P. J., 309 Steele,B. R., 231 Steliou,K., 165 Stensen,W., 7 Stephen,E., 154 E. K.,112 Stephenson, G. R., 102 Stephenson, Stern,A. J., 205 J. A., 215 Sternberg, M. F. G., 11 Stevens,

P.,91',248 Stevenson, Stewart,L. J ., 173 Still,w. C.,194 S t i n n ,D . 8 . , 2 4 6 S t o l l ,A . T . , 2 3 1 Stone,M. P., 143 Stork,G., 64,258,327 Strating,J.,209 Strazzolini,P., 13 J. B., 167 Strickland, Stringer,O. D., 218 Strube,R. E., 156 S t r u c h k o v\ ., T . , 2 4 Stryker,J. M., 166 Stylianides,N. A., 248 Su, H., 365 Suafez,E., 151 Sudrez,E., 258 Subramanian,L. R., 339 Suchisimita,194 Suckling,C. J., 250 Sudhakar,A. R., 259 Sugano,Y., 113 Sugihara,Y., 336 Sugimori,A., 340 Sugimoto,A.,78 Sugimura,T., 287 H., l'14,200 Suginome, Sugiura,Y., 221 Sugumi,H., 360 Sukarai,H., 40 Sukata,K., 346 Sumi,K., 176 Sumiya,R., 31 L., 32 Summers, Sumpter,C. A.,280 J., 153 Sunamoto, Suri,S. C., 14 J. D., 353 Surmatis, R.,21'7 Sustmann, Siitbeyaz,Y., 243 Suzuki,A., 49,122,192 Suzuki,H., 272 Suzuki,K., 119,121 Suzuki,M., 148,185,349 Suzuki,T., 294 S v e n d s e Jn ., S . , 7 , 2 4 0 Sviridova,L. A., 285 S w e n t o nJ,. S . , 2 0 5 Switzer,C. Y., 335

Sworin. Sydnes Syper.L

Tachina Taddei. Taffer. I Tagliavi Tai, A.. Takagi. Takaha Takaha Takaha Takaha Takai. I Takaku Takami Takano Takaok Takata Takatsu Takaya Takeda Takeda Takei. I Takena Takeno Takeuc Takeud Takeuc Takeuc Takino Talben Taljaar Tamaga Tamak Tamao Tamura Tamura Tamura Tanaka Tanaka Tanaka Tanaka Tanaka Tanam Tanena Tang. lt Tanigrx Tanika

AuthorIndex S w o r i nM , .,312 S y d n e sL,. K . , 7 Syper,L., 167,190 Tachinami,T., 53 T a d d e iM , .,41,62 T a f e r ,I . M . , 1 9 4 Tagliavini,G., 65 T a i ,A . , 2 8 7 Takagi,K., 359 Takahara,J. p., 309 Takahashi, A.,245 Takahashi, H., 52_53,54 Takahashi,T., 3 Takai,K., 96 Takaku,H., 36 Takamine,K., 366 T a k a n oS , .,341 Takaoka,y., 176,177 T a k a r aT, . , 2 0 4 , 3 0 5 Takatsuka, S., 109 Takayanagi, M.,124 Takeda,H., 53 T a k e d a , 7 . , 3 3 1, 0 0 Takei,H., 89 Takenaka,S., 145 Takenouchi, K., g9 Takeuchi,A., lg5 Takeuchi,K., 190 T a k e u c hS i,.,277 Takeuchi,y, 3 Takino,y.,260 T a l b e r tJ, . , 2 3 0 Taljaard,H. C., 187 Tamagawa, H., 120 T a m a k iK , .,172 Tamao,K., 135,364 Tamura,J., 349 Tamura,M., 15 Tamura,y., 257 Tanaka,H., 182,2Bg Tanaka,K.,59, 140,262,281 T a n a k aN , .,262 T a n a k aS, . , 6 1 Tanaka,T., 25, 59, 135 Tanamachi, H., 153 T a n e n a k aS,. , 7 2 T a n g ,K . , 6 3 Taniguchi, H., 366 Tanikaga,R.,262

Tanimoto,S., 156 y.,355 Tankguchi, Tanko,J., l0g Tanner,D., 62 Tanoue,y, 71 Tardella,p. A., 155 Taticchi,A., 356 Tatsuno,T.,2g7 Taunton,J., 2g0 Taveras, A. G., 57 Tawarayama,y.,221 Terada,A., 71 Terada,M., 27 T e r a n i s hSi ,. , 2 1 6 Terkle-Huslig,T., 293 T h e a ,S . , 1 9 Thebtaranonth, C., 162 Thebtaranonth , y., 162 T h e l l e n dA, . , 3 2 3 Thdrien,M.. 307 Thoer,A., il4 Thomas,E., 6l Thomas,M., lg Thomas,R. D., 202 Thomas,S. E., 334 T h o m p s o nC, . M . , 4 7 , 2 6 2 Thompson,D. p., 165 Thompson,R. C., 76 Thomsen,I., g6 Tietze,L. F., 88, 159 T i l l y e r ,R . D . , 2 2 8 Timofeeva,T. V., 24 Toda,F., 135,140 T o h m a ,H . , 2 5 7 Tokoroyama, T., 31g,345 Tokuda,M., 200 T o l m a nC , . A., 12g Tominaga,y., 2tg, 263, 305, 33: , 341 Tomioka,K., 166,1g2 Tomita,K., 160 T o m o d aS , .,29 Toong,Y. C., 7 Torii, S., 182 Torra,N., 219 Torssell,K. B. G., g6 Tour, J. M., 123,231 T o y a ,T . , 2 8 T r e h a nS , .,201 Trogolo,C., 199 Troisi,L., 212

392

Author lndex

T r o m p ,C . M . , 2 1 7 T r o s t ,B . M . , l . 1 0 8 .2 5 9 . 3 5 3 , 3 5 4 Trova,M. P.,60 Trowitzsch,W., 208 Truce,W. 8.,356 Tse,C.-W.,108 Tsuboi,S., 109 Tsubuki,M.,28 G.,l2l Tsuchihashi, Tsuda,T., 30,31 Tsuji,J., 249 Tsuji,Y.,280 Tsukamoto,M.,345 Tsukazaki,M., 187 Tsukui,T., 347 Tsunoda,T., 231 V. 4.,24 Tsyryapkin, Tuis,M. A.,201 Turnbull,K. D.,369 Tykwinski,R., 175 Ube Industries,Ltd., 136 Uchikawa,O.,303 Uchino,N., 359 U c h i r o ,H . , 3 6 0 Uchiyama,T., 216 U d o d o n gU , .,50 U e d a ,K . , 2 8 Ueda,Y., 195 U e j i m a ,M . , 3 2 6 Ueki, M., 145 Ugi, L, 307 U g r a k ,B . I . , 7 7 Ukaji, Y., 191,238 U l o t h ,R . H . , 3 2 Umano,S., 32 U m e k a w aH, . , 6 9 Umemoto,T., 160 Urata,H.,249 Urban, R., 307 Urbanowicz,J. H., 300 U r p i ,F . , 2 1 9 Urso, F., 82 Ushio, Y., 338,367 Utaka,M., 109 Utimoto, K., 96, 329,333,337 Uyehara,T., 185 Vhgberg,J. O.,245 V a i d ,R . K . , 1 7 6 Van Boom,J . H., 217

Van der Heide, F. R., 279 Van der Marel,G. A.,217 Van Der Puy, M., 160 Van der Steen,F. H., 370 Van Duzer, J . H., 253 Van Eyk, S. J.,309 Van Koten,G.,370 Van Leusen,A. M., 209 Varvoglis,A., 259 Vassilara,G., 38 Vaughan,K., 1l Vaultier,M.,44 Veal,W. R.,279 Vederas,J. C.,23 Venkataramani,P. S., 18 Verardo,G., 13 Viader, J., 346 V i c e n t eM , .,211 Vilar, E. T.,339 Vilarrasa,J., 219 Vile, S., 239 Villani,R., 128 V i l f e m i nD , .,214 Villieras,J., 133 VisaniN , .,238 L. C.,218 Vishwakarma, Vismara,E., 173 Vitt, S.V.,24 Volante,R. P., 85, 338 Volbach,W., 341 Vo-Quang,L., 294 Vo-Quang,Y.,294 Vorbriiggen,H.,260 Vorndam,P. 8.,231 W a d a ,F . , 6 9 W a d a ,M . , 3 7 Waegell,8., 156,207 Wagner,A.,352 W a i ,J . S . M . , 2 4 0 S., 249 Wakabayashi, Walder,L.,365 W a l i ,A . , 3 5 5 W a l k e rD , . M.,319 Walling,C., 128 W a l l i sE , . S.,257 W a l s hE , . J.,278 Wang,B. S. L., 184 W a n g ,D . , 5 5 Wang,W., 169 M. W,81 Wannamaker,

Ward. D Wariish Warner. Warren. Warshar Wasserr Watana Watana Watana Watana Watson Wee,A. Wehme W e i ,J . . Weiner. Weinreb Weinsto Welch.J Wender Wenger Wenken Wensin Weston Whitehc White. J Wicha.J Wicks.( Wieber. Wietfeld wild, s. Wiley. I will, B.. Williams Williarm Wilson.i Winkler Winotai Winters Wirth. T Wisnief Wisznie Witschc Witzel.' Wojciec Wolfe. J Wolfi, C Wong, H Wong,J Woodga Worakur Wright. I

Author Index

Ward,D. E., 290 Wariishi,K., 310 Warner,C. D., 288 Warren,S., 291 Warshawsky, A. M.,276 Wasserman, H. H., 253 Watanabe, H., 190 Watanabe, M., 157,187 Watanabe,T., 347 y., 107,1lZ, Z80 Watanabe, W a t s o nB, . T . , 8 1 W e e ,A . G . H . , 3 1 6 W e h m e y eR r ,. M . , 9 9 , 2 2 2 W e i ,J . , 4 1 Weiner,M. A., 231 Weinreb,S, M., 128,297 Weinstock, L. M., 73 Welch,J. S., 293 Wender,P. A., 131 Wenger,E., 16 Wenkert,E., 199,356 Wensing,M., 134 W e s t o nW , . A.,271 W h i t e h e a dM, . , 2 5 7 White,J. C., 130 Wicha,J., 45, 328 W i c k s ,G . E . , 1 4 4 , 1 6 0 Wieber,M., 114 Wietfeld,B.,346 witd, s. B.,265 Wiley, M. R., 131 wiil, B., 243,322 W i l l i a m sD , . R.,47 Williams,R. M.,64 Wilson,S. R., 236 Winkler,J. D., 331 W i n o t a iC , .,41 Winters,R. T., 74 Wirth, T., 331 Wisnief,T. J.,278 Wiszniewski,V., 255 Witschel,M. C., 16l Witzel,T.,327 Wojciechowska, W., 328 Wolfe,J., 162 Wolfr,C.,242 Wong,H. N. C., 108 W o n g ,J . , 9 9 Woodgate,P. D., 47 Worakun,T.,91,248 Wright,B. B., 196

W u ,A . , 2 9 2 Wu, G., 123 W u ,H . , 2 9 8 Wu,S.,340 Wu,T.-C.,99 Wu,2.,251 W u l f f ,W . D . , 9 4 , 9 5 , 2 2 5 Wyborney,M.,294 Wyvill,D.,282 Xiao, C.,232 Xie, L., 298 Xin, Y.,325 Xu, S. L.,296 Xu, W., 129 Xu, Y.,299 Y a k o u t ,E . - S .M . A . , 2 6 7 Yakura,T., 257 Yam, T. M., 184 Y a m a d aH , .,305 Yamada,J., 342 Y a m a d aK, . , 6 1 , 3 1 0 Yamada,S., 174 Yamada,T., 103 Y a m a d aY, . , 2 2 , 2 0 0 Yamaguchi,M., 46, 204, 284 Yamaguchi, R., 329 Y a m a k a g eS,. , 3 6 Y a m a k a w aK, . , 7 8 Y a m a m o t oH, . , 2 , 2 6 , 4 2 , 6 5 , 1 3 6 ,1 4 0 r4t, 157, 204, 205,22r, 239, 251, 315 Y a m a m o t oM, . , 6 1 , 3 1 0 Yamamoto,Y., 54, 185,342 Yamanoi,T., 73 Yamanoue, M., 182 Yamaoka,S., 115 Yamashina, N., 49 Yamashita, D. S., 252 Yamashita, S., 182 Yamashita, T., 182 Yamauchi,T., 172 Yamazaki,N., 193 Yanagiya, M.,298 Yanase,M.,341 Yang,B., 325 Y a n g ,H . , 5 9 Yang,J., 350 Yang,R.-Y., 150 Yano, T., 84 Y e h ,M . C . P . , 2 2 5 , 2 3 0 , 2 3 2

3!)4

Author Index

Yip, Y.-C., 108 Yokoyama,M.,221 Yokoyama,S.,219 Yonemura,K.,56 Yoon, D. C.,218,275 Yoon, U. C., 129 Yoshida,E., 114 Yoshida,J., 364 Y o s h i d aM , ., 18,218 Yoshifuji,S., 281 A.,294 Yoshikoshi, Yoshimura,N., 367 Yoshioka,H., 286 Y o u n ,I . K . , 2 4 1 Young,R. N.,307 Young,S. M.,293 Y u a n ,G . , 3 2 5 Yura, T., 313 Y u s ,M . , 6 4 Zabrowski,D. L.,144 Z a h l e r ,R . 8 . , 3 5 2 M.,83 Zaidlewica, Zakrzewskt,J., 292

Zefrrov,N. S.,76, 175 Zenki, S., 295 Zhang, J ., 350 Zhang, N., 236 Zhang,X.,292 Zhang,Y.,283,301,302 Zhang, Z-d.,365 Zhao,J.,325 Zhao, K.,258 Z h a o ,S . , 2 6 8 Zhdankin,V. V.,76, 175 Zhou,B.,299 Zhol,X.,293 Zierke,T.,67 zi, H.-8., 300 Z i m a ,G . , 5 8 Zimmerman,J. W,34 Zimmermann,G.,137 Zipkin, R. 8.,194 Zoghaib,W. M.,290 Zon, G., 155 Zubieta, J ., 63 Zuccarello,G., 2'11 Z i i g e r ,M . , 5 1

SUB

Acetals. 2-Aceta (Z)-2-Ao Acetic ar Acetoac Acetonit (Z)-t-Aa 3-Aceto 2-(Aceto 1-l o-(2-Acc Acetylao Acetylcy o,p-Ace N-Acet1 Acridox Acrolein Acyclox Acylami Acylatio N-Acyl-l Acyl iso< Acylmet N-Acylo Acylsila 3-Acyltc 2-Acylth Adam'sr 1,2-Add 1,4-Add 1,6-4'dd Adeninc Aflatoxi AIBN.T Aldimin Aldol re Aliquat Alkali al 1-Alkelx Alkenl'li l-Alkenl 2-Alken Alkenyl Alkenyb ct-Alkor

SUBJECTINDEX Acetals,121 o-Alkoxy aldehydes,45 2-Acetamidoacrylic acids,53 2-Alkoxy-1,4-benzoquinones, 321 (Z) -2- Acetamidoacrylicacids,54 B-Alkoxy aldehydes,232-233 Acetic anhydride-Pyridine, 1 B-Alkoxy ketones,185 Acetoacetatedianion.46 Alkoxycarbonylfurans, 70 Acetonitrile,I ketones,185 B-Alkoxy-B'-hydroxy (Z)-l-Acetoxy-2-benzyloxyethylene, 208 o-Alkoxylithiums, 60-61 3-Acetoxyglycals, 15I o-Alkoxyorganocuprates, 227 2-(Acetoxymethyl)-3-trimethylsilylpropene,p-Alkoxyphenols,257 t-2 Alkoxysilanes,33 o-(2-Acetoxy-2-nitrosylethyl) ketone,71 Alkylaluminumhalides,2-5 Acetylacetone,368 2-Alkyl-4-aminoquinolines, {.l7 Acetylcyclopentadienes, 368 Afkylaryl azides,126 cr,B-Acetylenic esters,194 S-Alkylation,109 N-Acetyloxyamides, 158 B-Alkyl-9-BBN,122 Acridones,187 p-Alkylbenzophenones, 367 Acrolein,140 a-Alkylbenzylalcohols,167-168 Acycloxyboranes, 2 Alkyl benzylketones,276 Acylaminocyclization,329 Alkylbis(t-butylphosphido)cup r ates,226 Acylationand alkylation,148 Alkyl bromides,352 N-Acyl-1,2-dihydroisoquinolines, 329 Alkyl carbamates, 101 Acyl isocyanates, 313 Alkyl chlorides, 89 Acylmethylationof arenes,320 Alkyl cobalt(III)bis(dimethylgloxime N-Acyloxyphthalimides, 37 anion)pyridine, 5-6 Acylsilanes,97, 226 ct-Alkyldeoxybenzoins, 367 3-Acyltetrahydrofurans, 45 5-Alkyl-3,5-dihydroxypentanoic acids,52 2-Acylthio-3-nitropyridines, 22 2-Alkyl-1,3-dithianes, 1l4 Adam's catalyst,268-269 Alkyl fluorides,288 1,2-Additions, 221 AIkyl halides,358-59 I,4-Additions,89,227,229 -5-Alkylidene-4,5-dihydrofurans, 172 I,6-Additions, 223 1-Alkyl-l-H-inden-l-ols, 234 Adenine,217 Alkyl iodides,367 Aflatoxin B, epoxide,143-144 Alkyl isocyanates, 101 AIBN, seeAzobisisobutyronitrile o-Alkyl-B-ketoamides,323 Aldimines,321 Alkylnaphthalenes, 27 Aldol reactions, 314-315,349.362 9-Alkylphenanthrenes, 27 Aliquat,253 N-Alkyl-3-(2,4,6-trichlorophenylamino)Alkali aluminumsilicares,367 pyridine,357 l-Alkene-4-ols,249 Alkyl vinyl ketones,109 Alkenyliodoniumtetrafluoroborates, 177 Alkylzinc chlorides,49 l-Alkenylstannanes, 69 Alkyne/estercoupling,194-195 2-Alkenylstannanes, 69 1-Alkynes, 40 Alkenylsulfoximines, 722 Alkynyl(phenyl)iodonium tosylares,6 Alkenylzincchlorides,49 1-Alkynyltriisopropoxytitanium, 6-7 n-Alkoxyallyltributyltins, 237-238 Allene.7

3%

SubjectIndex

Allenylsilanes,7-8 o-Allothreonine,171 N-Allylacetamide,197 Allylamines,20 Allylation, 309 335 Allylation/Methoxycarbonylation, Allylboranes,67 Allylboration,9 Allylboronate,9 9 B-Allyldiisopinocamphenylborane, . 28-29, l5l Allylic acetates Allylic alcohols, 45, 6'7, 68 Allylic carbonates,299 Allylic diethylboranes, 83 Allylidenationof aldehydes,303 Allyl ketenedithioacetals,360 3l-32 Allylnickel homoenolates, Allylsilanes,72, 107 Allyl telluroxides,20 197 N-Allyltrifluoroacetamide, Allyltrimethylsilanes, 8, 15, 164 (Z)-Allyltrimethylsilanes, 345 (S)-B-Allyl-2-(trimethylsilyl)borolane, 8-9 9 B-Allyltrimethylsilylboronate, (Z)- Allyl alcohols, 193 Al-Mont,213 Alumina, 9, 172-173,173,292 Aluminum bromide,18 Aluminum chlorate,7l Aluminum chloride,10 Aluminum(III)iodide,10 Aluminum3* -Montmorillonite, l'l 8-179 Amberlyst15, 178 AmberlystII-15, 159 Amides.197.300 Amidines,269 Amination,17l Amines,317 1.2-Aminoalcohol.265 2-Amino glycosides,111 53 0-Aminoacetophenones, c-Amino acids,110,256-257,340 o-Amino aldehydes,49 dnti-B-Amino alcohols,289-290 267 2-Amino-6-arylaminopurines, 10- 1I O-(2-Aminobenzoyl)hydroxylamine, B-Amino acids,150 P-Amino alcohols,16-17, 111,306 17 Aminodiazoniumtetrachloroaluminate, Aminodiazoniumtriflate, l7 113 2-Amino-4,6-di-l-butylphenol,

c-Amino-B-hydroxyacids,106 (S)-(- )-Amino-2-(1-methoxy-1-methylethyl)pyrrolidine(SADP), 11 2-Amino-3-methyl-l,l-diphenylbutanol-1, 168 ro-Aminoesters.337 111 Aminopolysaccharides, (R)-o-Amino acids,307 Ammonia-Aceticacid, 12-13 Ammonium chloride.13 Ammonium formate-Palladiumcatalyst, 13-14 Ammonium nitrate-Trifluoroacetic anhydride,14 74 Anionic polycyclization, Anizole(tricarbonyl)anisole,16 13 + 2 + llAnnelation, 302 [3 + 2]Annelation,7-8, 238,272-273,302 Anthracene. 99-100. 275 Antimony(V) chloride-Tin(II) iodide14-15 Chlorotrimethylsilane, Antimony(V) chloride-Tin(II) l5 trifluoromethanesulfonate. o-Arabinose,96 Arene dioxides,143 l0l Areneisothiocyanates, Arene oxides,275 15-16 Arenesulfenylisocyanates, Arenesulfinicacids,166-167 Arene thiocyanation,101 complexes,l6 Arene(tricarbonyl)chromium Aromatic amination,17 Aromatization,101 Arylation, 300 C-Aryl glycosides,119 1I 4-Aryl-1,4-dihydropyridine, Aryl ethers,270 Aryl formates,167 l5 Arylsulfenylcarbamates, 242 3-Arylsulfonyloxazolidines, 4-5 N-Arylsulfoximines, Aryltin,225 344 2-Aryl-1-trimethylsilylethylenes, ( + )-Aspicilin,137 Asymmetrichydroboration,34 Asymmetrichydrogenation,53, 53-54 Asymmetrization,251 Aucubin, 198 2.2]octan-3-ol, 109 1-Azabicyclo[2. 303 3-Aza-Coperearrangement, 75, 304 2-Aza-1,3-dienes,

Azam Azetk Azeti< 3-Azi( to-Azi a-Azn Azido Azido Azido I!

Azido f( Azirit Azob Azon Azulr

Baelr I Bariu Bariu Benz Benz Benz Benz Benz Benz Benz Benz Bend Benz Benz Benz Benz (R).8 Benz Benz l,+B Benz Benz (2R.3 p 2-Ben Ben4 Ben4 1-Be l-Ben Ben4 B.n4 Ben4 Bena

SubjectIndex 3n Azametalacyclopentenes, g1 (E)-Benzylideneacetone. 344 Azetidinone,207 Benzylidenes. 342 Azetidinoneepoxides,195 N-Benzylimines, 2 3-Azido1,2-diols. 110 Benzylmanganesepentacarbony o-Azidoalkeneboronic l. 234_235 esters.44 trenzylDL_mannopyranoside, o-Azido carboxylicacids,110 20g N-Benzyl-2-methylaziridine, Azidohydrins,16_17, 342 216 N-(Benzyloxycarbonyl)_r_-serine Azidotrimethylsilane, B_lactone, 126 Azidotrimethylsilane_Aluminum Benzy^loxymethylenetriphenylphosphorane, isopropoxide,16_17 zJ- z4 Azidotrimethylsilane /Trifluoromethanesul_ (S)-o-[N-(Benzylproloylamino)benzophen_ fonicacid,17 one.24 Aziridines,82_g3,216 Benzylsulfonyl chlorides.344 Azobisisobutyronitrile. 25 Benzyltriethylammoniumchloride, Azomethineylides,132 274_ Azulenes,7-g.172 BenzyJtrimethylammonium dichloroiodate, Baeyer-Villigeroxidation, 14g, 163_164, Benzyltrimethylammoni um lo/ tetrachloroiodate. 25 Barium ferratehydrate,lg Benzyltrioctylammonium chloridc,29 Bariummanganate, lg Benzynes, 1g7 Benzene(1,3-cyclohexadiene)iron, 110 Bicyclico-pyrans,30_31 Benzeneselenenyl chloride,g6 Bicyclic o-pyrones,30_31 Benzeneseleninic acid, 1g ot ( R ) - 1+ 1 -I . 1' - g i - 2 . 2 , - n a p h t h( B INOL)_ Benzeneseleninic anhydride.lg Dichloro_ or dibromodiisopropoxyr;ran_ benzeneseleninyl chloride.lg ium,26-27 Benzenesulfenyt chloride,l9 1,1'-Bi-2,2,-naphthol,26 Benzenetellurinic anhydride.l9_20 Binaphthols,65 uenzenetellurinyl triffuoroacetate, 20 Binaphthylsilocyclohepranes, Benzil,277 236_237 2,2'-Bip_yridyl(1,5-cycl,ooctadiene)nickel, Benzocyclobutenes, 2g 185 Benzofurans,246,301 Biquinones, 3g Benzoicacids,lg Birch reduction,2T_2g Benzoin,254-255 o-Bisabolol.234 (R)-Benzoin,277 Bis(acetonirrile )dichloropalladium( Benzoindolizidin_3_ones. I I). 2g_ 329 to Benzophene,129 Bis(N-aryt-4,4-dimethyl-2_oxazotinylidenes, 1,4-Benzoquino nes,296 124 Benzothiazole,20_27 )dichtoropailadium( Benzoxazoles, 275 rr.).2e (Pj:t K ) -|1"::":1.,]e f r s - I( . l ' - B i n a p h t h a l e n y l ) (2R.3S)-N-Benzoyt_O_( diselenide, I _ethoxyethyt)_329-30 pnenytrsoserine,152 Bis(slzr-collidine )iodine( I) perchlorate, 2-Benzoylthio-3-nitropyridine, 30 2I nrs(cyclooctadiene )nickel(0). uenzylamides, 30_32 64 urs(cyclopentadienyl Benzyl chloroformate, 22 )dihydrozirconium, 32 rrs{cyctopenradienyl)diphenylritanium, I -Benzyl-cr-3,4-dimethylazetidinone, 32_ 2 I 6 JJ t - aenzyt-cis _2.3_dimerhylaziridine, 2I 6 Bis(dib.enzylideneacerone)palladium(0)_ Uenzylfluoride,76 Tri(2-furyl)phosphine. Benzylicchlorination.25 3J Bis(dibenzylideneacerone Benzylicorganocopperreagents, )palladium. 302 225 l.d-rlls(drmethylamino benzytrcoxidation,2j 4 )naphthalene, 364 1.6-Bis(dimethylamino)pyiene, 37

39E

SubjectIndex

Bromine-Meth anol, 47- 48 33-34 p-Bis(diphenylhydrosilyl)benzene, chloride,165 (R)-and (S)-2,2'-Bis(diphenylphosphine)-
Butyllit 63 2+-Buq lE N-r-Bu FButyl t-Butyl FButyl Pr) t-Butyl (tn FButyl pct FButyl chl t-Butyl drc t-Buryl act t-Buty' Butyltri 2-Buty 3-Buty "y-Butv

Butyrol 1-Buty

Calciul Calichc Camph d-Carry Campb Campb Camph Camph Camph Camph Carbap Carboo O-Carb Carboa (Carbc rlr< (Carbc rtx Carbor Carbor Carbor p-Caro Carvoc Catech

SubjectIndex

Da -h.t, n.

ai

I : , ph.x-

rt,rlrJlnr-. Fii,rrUphrn,. t-

:dl

h:

399

Butyllithium-Tetramethylethylenediamine, Cationiccyclization,108 63-64 Celite,102 2-l'Butyl-5-methylene1,3-dioxolan-4-one, Cerium(III) chloride,72-73 t8t Cerium(IV) ammonium nitr ate, 70-7 2 N-t-Butylnaphthalenesulfonamides, Cerium(IV) sulfate,73 28 t-Butyl ethers,159 Ceroubenicacid-III. 158 t-Butyl hydroperoxide,175-76,187 Cesiumcarbonate,73-74 /-Butyl hydroperoxide-( + )-DET-Ti-(O-tCesiumfluoride,75-76 Pr)., 55-56 Cesiumfluoride-18-Crown-6, 76 t-Butyl hydroperoxide-DichlorotrisCesiumfluoroxys,.tlfate,76-77 (triphenylphosphine)ruthenium(II), Cesiumphenolates,74 56 t-Butyl hydroperoxide-Dioxobis(2,4Cetylpyridiniumbromide,253 pentanedionate)molybdenum, Cetyltrimethylammonium 56-57 bromide,'13, 71, t-Butyl hydroperoxide-Pyridinium 78.252-253 chlorochromate. 57 Cetyltrimethylammonium chromate,77-78 t-Butyl hydroperoxide-Pyridinium Chiral Host Ace, 136 dichromate,57 Chiral phase-transfer catalyst,340 l-Butyl hydroperoxide-Vanadyl Chiral sulfinates,277 acetylacetonate, 57-58 Chloramines,292 t-Butyl 3-keto-4-hexenoate, Chloramine-T.78 58 Butyltrichlorotin,65, 65-66 Chlorination,18 2-Butynal,66 Chlorinationof aldoximes,86-87 3-Butyn-l-ols, 7 Chlorinationof alkylarenes,25 249 Chloroacetonitrile. 325 1-Butyrolactols, l-Chloroalkanes,253 Butyrolactones, 126-127, 333 l-Chloroalkylphenylsulfoxides,78-79 249 1-Butyrolactones, B-Chloroalkylsulfides,146 Calcium acetate,46 o-Chloroselenides,336 p-Chlorobis(cyclopentadienyl)(dimethylCalichemicins, 248 Camphanoylchloride,67 aluminum)p-methylenetitanium, 79 d-Camphor,59 Chlorobis(cyclopentadienyl)hydridozirconCamphoricacid,67 ium. 80-81 Camphorquinone, 67-68 Chlorobis(cyclopentadienyl)methylzirconCamphor-1O-sulfonic acid, 68 ium,81 Camphorsulfonic acid, 97, 16l, 251 Chlorobis(cyclopentadienyl)titanium(III), Camphor-1O-sulfonyl chloride,68-69 8t-82 Camphorylsulfonyloxaziridine, 41 Chlorodicarbonylrhodium(I) dimer, 82-83 Carbapenem( + )-PS-5,181 Chlorodiethylborane, 83 Carbonylation,82, 247, 252, 355 a-Chloroethylchloroformate,83-84 O-Carbonylation,297 Chlorofluorocarbene,320 Carbonylationof benzylchloride,72-73 Chlorofluorocyclopropanes,320 (Carbonyl)chlorobis(triphenylphosphine)- Chloroform,84 rhodium,69 Chlorohydrins,333 (Carbonyl)hydridotris(triphenylphosphine)-3-Chloro-2-hydroxy ketones,146 rhodium, 69-70 2-Chloro-3-hydroxy ketones,146 Carboxamides, 319 3-Chloro-l -hydroxytetrabutyldistannoxane, Carboxylation,196 84 Carboxylicacids,118 a-Chloroketones, 92-93, 102 p-Carotene,303 3-Chloromethylcephems, 33 Carvone, 206 Chloromethyllithium,85 Catecholborane. 2-Chloro-1-methylpyridinium 34. 91 iodide,85

400

SubjectIndex

acid, 86, 163 rn-Chloroperbenzoic 86-87 N-Chlorosuccinimide' sulfide,88 N-Chlorosuccinimide-Dimethyl B-Chlorotetrahydrofurans,282-283 ChlorotriisoproPoxYtitanium,6 89, 97 ChlorotrimethYlsilane, Chlorotrimethylsilane-Seleniumdioxide, 89 Chlorotrimethylsilane-Zincchloride, 89-90 Chlorotris(triphenylphosphine)rhodium, 90-92 vic-Chloroesters,98 ALCholestene,173 Chromanone,330 Chromic actd,92 92-93 Chromicacid-Chlorotrimethylsilane, Chromiumcarbenereagents,93-94 Chromium(II) chloride Chromium(Il) chloride-Nickel(II)chloride' 96-97 Chromones,54 Cinchonidine,89 Cinnamylchloride,100' 309 Citronellal,266 (R)-Citronellal,159 Citronellicacid, 154 46 Claisencondensation, 205 Claisenrearrangement, Claycop,101 Clayfen,101 Cleavageof Yic-diols,56-57 Cleavageof disulfides,284 Cleavageof ePoxides,7, 163 oximes,and Cleavageof hydrazones. 178 semicarbazones, Cleavageof BJactones,270 reduction,13 Clemmensen-tYPe Cobaloximes,5 Cobalt carbonYl,72 Cobalt(II) chloride,97-98 ( + )-Colletodiol,131 54, 98-99 Collidinep-toluenesulfonate, Compactin,272,316 Conduritol-A,243 Conj ugate addition, 222 Conjugatereduction,204 Copper,99 Copperfluoride,364 Copperhydride, 132 Copper(I) bromide-Dimethylsulfide,100101 Copper(I)chloride,101

Copper(Il) acetate,70 99-100 Copper(Il) acetate-Anthracene, Copper(Il) bromide, 100 Copper(II) nitrate-Montmorillonite,101 Copper(I)iodide, 173 Copper(I)thiocyanate'101-102 CopperslurrY,99 Corey-Kim reagent,50, 88 Cross-couplingof alkYnes,80 198 Cross-dehYdrodimerization, Crotylation, 75-7 6, 318-319 75 Crotyltrifluorosilanes, 18-Crown-6,75, 357 Cyanation,359 c-CyanovinYl sulfides'102 chloride' Cyanomethyldibutyltelluronium 298 Cyano(methylthio)methyltrimethylsilane'

r02

chlorochromate,102 2-Cyanopyridinium 15, 102-104,126' Cyanotrimethylsilane, 346 Cyanuricchloride,105 Cyclicamides,158 CyclicenediYnes,271 Cyclicethers,78-79 Cyclicsulfatesof 1,2-diols,105-107 Cyclicsulfides,165 91 Cyclizationof 1,6-enYnes, amines,200 Cyclizationof 6,e-unsaturated CyclizativeHeck couPling'301 94, 95,129,207[2 + 2]Cycloadditions, 208,321 132 [3 + 2]Cycloadditions,32, 58, 171,129' 14'7 [+ + ZiCyctoaOditions, 131-132 [4 + 4]CYcloadditions, 317 1,2-Cycloalkanediols, Cyclobutanation,130 94 Cyclobutanones, 60 Cyclobutenones, 216 CyclocarbonYlation, 275 Cyclodesulfurization. B-Cyclodextrin'107 190 1,3-Cyclodisiloxane' 729 1,3-Cyclohexadiene, I .4-diene.243 CyclohexaCO )zlndenYl Cvclohexadiene-Mo( 212 comPlexes, 57 2,5-Cyclohexadien-1-ones' 185 Cyclohexanes, Cyclohexanones,248-249

Cyclohexc Cyclohexc Cyclohexr Cycloleuc (Cycloocta ruthe! 1,5-Cyclm Cyclopenu Cyclopenu Cyclopent Cyclopen Cyclopen 2-Cyclopo Cyclopeo Cyclopeo Cycloprog Cyclopro Cycloprq Cycloprq Cycloprq tetrd Cyclospc Cyclothk

Dakin-ll o-Damas Dan Shc Daphnila Daphnifl Darvon : Darzens xylo-Dau Dealk-vl Deamiu O-Debct Debrom De-t-bu cis-Deca Decarbo Decarbo Deeoxn Deglycu Dehydn Dehydn 9,ll-H Dehydn Dehydn Dehydn Dehydn Demeth 5-Deon

SubjectIndex tnc. +/- 100 r i , ' n r r c .1 0 1 l, l

, lq\

n:,hloride. r:rr lrilsng. Dn:.r:e.102 - . . . r .l 1 6 .

a::rncs.200 I

: :., l( )7I . ,:,, 1{7

:

Cyclohexene oxide, 26 Cyclohexenes, 130,210 Cyclohexylimines, 133 Cycloleucine,319 (Cyclooctadiene) ( 1,6-cyclooctarriene)_ ruthenium,107 1,5-Cyclooctadienes, 331_332 Cyclopentadienes, 36g Cyclopentanemethanols, gl Cyclopentanes, 185 Cyclopentannelation, 201 Cyclopentanon es,272, 347 2-CyclopenteneI -ol, 365 Cyclopentenes, 134 Cyclopentenones, 57-58,l1:., 123,216, 235 Cyclopropanation, 59, I 17, 2j8_279, 2A.l Cyclopropanation of lactams.147 Cyclopropanes. l0g, 147 Cyclopropropylmethyl radicals,324 Cyclopropyldiphenylsulfonium tetrafluoroborate,10g CyclosporinA, 85 Cyclothiophosphorylation, 30g Dakin-Westreaction,I o-Damascone, 154 Dan Shen.363 Daphnilactone, l2 Daphniphyllumalkatoids,l2 Darvon alcohol, 131-132 Darzenscondensation.132 xylo-Daunosamine, 3 Dealkylationof esters,293 Deamination, 331 O-Debenzylation, 311 Debromination, 293 De-r-butylation,l0 crs-Decalins, 58 Decarbonylation, 90, 2g3 Decarboxylation, 37, 20g Deeoxygenation of ROH, 33_34 Deglycosidation, 50-51 Dehydration,267, 336 Dehydrobromination, 60 9,11-Dehydrodigitoxigenin, 32g Dehydrodimerization, l9g Dehydrogenation, 110, 175. lgg Dehydrohalogenation, 188 Dehydroiodination,172 Demethoxylation,269 5-Deoxyanthracyclines, 26g

401

Deoxygenation,120,243, 310 Deoxygenationof alcohols,333 Deoxygenationof epoxides,10 Deoxygenationof oxides.2g4 Deoxyribonucleotides, 36 2-Deoxysugars,327 Deselenation, 216 Dess-Martinperiodinane,252 Desulfonylative coupling,29 Desulfuration, 151,184-lgg,275,32g Dethioacetalization, 255, 25g yrc-Diacetates. l9-20 Diacetonylselenium dichlorides,336 e,B-Dialkoxyketones,193 (Dialkoxymerhyl)lirhium, 23I Dialkylacetals,ll4 1,2-Dialkylidenecyclopentanes, 354 1,4-Dialkylnaphrhalene, 104 2,4-DialkylI -naphthols, 104 Dialkylnitroloosmiumchromates,236 crs-9,10-Dialkylphenanthrenes, 2g 2,6-Dialkylphenols, 120 Dialkylzincs, lZ2,219 Dialkynyl ketones,259 1,2-Diarylethylenediamines, 321 Diaryl ketimine.l3 1,4-Diazabicycl o[2.2.2loctane,109 1,8-Diazabicyclo[5.4.0]-7-undecene, 109_ 110 Diazidoiisopropoxytitanium, I l0 Di(benzene)chromium. I 10 1,2-Dibenzoylb enzene,252 l-N,N-Dibenzyl-o-amino aldehydes, 1l0_ lll Dibenzylammonium trifluoroacetate,52 Dibenzylazodicarboxyla te, I I l-l12 Dibenzylphosphorochloridate, 1l2 Dibenzylphosphorofluoridate, I 12 Dibenzyl-r--tartaric acid, 26g 3,3'-Dibromol, 1,-binaphthol, 136 4,4-Dibromocyclohexadienone, 174 1.3-Dibromo-3,5-dimethylhydanroin, I 12_ ll3 1,3-Dibromo-5,5-dimethylhydantoin, 2g7 2,2-Dibutyl-2-stanna-1,3-dithiane, I l4_l t5 Di-r-butylazodicarboxylate, 171 I,2-Di+-butylbenzenes, 1l5- I 16 3,5-Di-l-butyl-1,2-benzoquinone, 113 Dibutylborylrrifluoromethanesulfonate. 1l3 2.6-Di-r-buryl-4-merhylphenol. I l3_l l4 2,6-Di+-butylphenol, 174

NZ

SubjectIndex

347 4,4'-Dicyanobiphenyl, Di-t-butyldicarbonate,113,245 300 Dicyanonaphthalene, 1,1-dioxide,1153,4-Di-r-butylthiophene 130 Dicyclohexylborane, 116 149 Dibutyltin bis(trifluoromethanesulfonate), Dicyclohexylcarbodiimide, Dicyclohexylcarbodiimide114 131 Dimethylaminopyridine, Dibutyltinoxide,116-117 131-132 Di(cyclooctadiene)nickel(0), 99 methylidenemalonate, Di+-butyl chloride,132 Dicyclopentadienylyttrium Di-t-butylperoxide,33 Dicyclopentylboryl 1,4-Dicarbonylcompounds,202-203 132 trifluoromethanesulfonate, Dicarbonyl(cyclopentadienyl)[(dimethylsul56-57 Di+erl-diols, uoroborate, tetrafl fonium)methyl]iron Diels-Alder catalysts,9, 54, 140-l4l' 117 355 171 Di-p-carbonylhexacarbonyldicobalt, 2, 3, 116,156,181, Diels-Alderreactions, 118 a/so Retro-DielsSee 356, 363. 208, p-carbonylhexacarbonyldicobalt-Methyl DiAlder reactions iodide,118-119 Dienals,133 Dichloro{1,l'-[bis(diphenylphosphine)]1.3-Dienes.223. 303 ferrocenepalladitm, 122-123 49 (E)-1,3-Dienes, Dichlorobis(cyclopentadienyl)hafnium104 Dienone-phenolrearrangement, Silverperchlorate,119-120 223 (E)-Dienones, Dichlorobis(cyclopentadienyl)titaniumo-Dienyl-o-allylacetates,354-355 120 Magnesium, Dichlorobis(cyclopentadienyl)zirconium, Diethylaluminumchloride,181 285 Diethylaminoethylcelluse, 120-l2r Diethyl aminomalonate,132-133 I .2-diphenylphosphino)DichloroIbis( Diethyl chloromalonate,134 122 ethane]nickel, 145 Dichlorobis(diphenylphosphinomethane)- Diethyl(methoxy)borane, Diethyloxalate,133 platinum(II),l2l 133 4-(Diethylphosphono)-2-butenal, Dichloro(1,4-bisdiphenylphosphinoproDiethyl tartrate, 140 pane)nickel, 122 Dichlorobis(triphenylphosphine)palladium,Diethyl thioxomalonate,134 Diethylzinc,207,268 49 -326 Dichlorobis(triphenylphosphine)palladium-3,3-Difluoro-I -butene,325 325-326 gern-Difluoropropanes, (rr\. 123-124 182 1.1-Dihaloalkenes, Dichloro(p-cymene)triphenylphosphine134-135 Dihalomethyllithium, ruthenium(II),124 Dihydridotetrakis(triphenylphosphine)125- 126 Dichlorodicyanobenzoquinone, ruthenium,135 103 Dichlorodiisopropoxytitanium(IV), 194 9,10-Dihydroanthracene, Dichloroketene,126-127 7 Dihydroazulenes, o,o-Dichloromethylmethylether, 85 321 Dihydrobenzofurans, 1,6-diphenylhexa1,6-Di(o-chlorophenyl)135 Dihydrogenhexachloroplatinate(IV), 136 2.4-diyne-1.6-diol. 186 Dihydronepatalactone, 1,1-Dichloro-1-phenyl'Z,2,211I Dihydrooxadiazine, e, 127-128 trimethyldisilan 2,3-Dihydropyran,2l2 107 ct.o-Dichlorosulfoxides, 86 3,4-Dihydro-2H-pyran, 1,2-Dichloro-I ,1,2,2-tetrasubstituted Dihydropyranes,170 190 disilanes, 101 Dichlorotris(triphenylphosphine)ruthenium,1,4-Dihydropyridines, 139 5,6-Dihydro-2-pyrones, 128, l'15 acids,24 Dihydropyrrole-2-carboxylic 129-130 9,10-Dicyanoanthracene, 130 B,B'-Dihydroxyketones,189 Dicyanobenzene,

2,2'-D t 2,2' b I

(l,2-

Dihyi (E)-r' Diisd I

Diisd Diisq 1,2-D 1,31,+D p,&D 2.6D 2,4-D Dilir

t

1,32,2-D 2,2-D 2,2-8

I I,l-D

(R.

t,t-:

Dim Din

I

Dirn

I

4-D

Dim Dim Dim

Dim N.O 1,3l.3-l Dim Dim Dim Dim Dim Dim

SubjectIndex

j

l:,

I

403

2,2'-Dihydroxy-1, 1'-binaphthyl,135-136, Dimethyl sulfoxide-Chlorotrimethylsilane, 140 146 2,2'-Dihydroxy-3,3'-bis(triphenylsilyl) 1,1Dimethyl sulfoxide-Phenyl binaphthyl-Trimethylaluminum, 136dichlorophosphate, 146-147 137 Dimethylsulfoxonium methylide,147 ( 1,2-Dihydroxyethyl)furans, 200 Dimethyl 1,2,4,5-tetrazine-3,6Dihydroxylation,88, 137,240-241,241 dicarboxylate,147-148 (E)-vic-Diiodoalkenes, 173 Dimethylzinc,148 Diisobutylaluminum 2,6-di+-butyl-43,3'-Diniljo-2,2'-dipyridyldisulfide, 21-22 methylphenoxide, 137 3,5-Dinitroperoxybenzoic acid, 148-149 Diisobutylaluminum hydride, 137-138 Dioctadecylcarbodiimide, 149 (Dioctyl)sodiumsulfosuccinate, Diisopropylcrotylboronates,138 149 1.2-Diketones. 276 1,1-Diodo-l-alkenes, 38 1.3-Diketones. 203 1.2-Diols.341 1,4-Diketones, 71, 158,175,203,334 1,3-Diols,366 p,6-Diketoesters,144-145 crs-Diols,173 2,6-Diketo-Aa-steroids, 43 syn-1,3-Diols, 185 2,4-Dilithio-1-butene, 184 1,4-Diones,255 Dilithium (trimethylstannyl)(2DIOP, See2,3-Isopropylid ene-2,3thienyl)cyanocuprate, 228 dihydroxy-1,4-bis(diphenylphosphine)1,3-Dimethoxybenzene, 269 butane 2,2-Dimethoxyoxetanes, 139 Dioxanes,347 2,2-Dimethoxypropane, 138 1.4-Dioxene. 149-150 2,2-Dimethoxypropane-Tin(II) chloride, 3.5-Dioxoalkanoates. 46 138-139 Dioxolanes,347 1,l-Dimethoxypropene, 139-140 Diphenylacetylene, 190 (R,R)-(+ )-Dimethoxy-N,N,N',N'Diphenyldiselenide,254 Tetramethylsuccinamide, 140 Diphenyliodoniumchloride,150 1,1-Dimethoxy-3-trimethylstannylpropane, Diphenylketene,306 237-238 Diphenylphosphinic chloride,150 Dimethylaluminumchloride,142 4-Diphenylphosphinyl-2Dimethylaluminum2,6-di-t-butyl-4(diphenylphosphino)methylpyrrolidine, methylphenoxide, 140-141 DimethylaluminumtrifluoroDipie-nylselenium hydroxyacetate, I 50- 151 methanesulfona te, 142-143 Diphenylselenurane, l5 I 4-Dimethylaminopyridine (DMAP), 1, 152, Diphenylsilane , 32-33 156,207 Diphenylsilane-Palladium(0)-Zinc Dimethyl azodicarboxylate,22 chloride.l5l Dimethyl+-butylsilyltriflate,89-90 Diphenyltitanocene, 33 Dimethyl 7,2-diazine-3,6-dicarboxylates, Diphosphorustetraiodide,151 1,47 Di-2-pyridylcarbonate,152 Dimethyldioxirane, | 43- | 44, 212 Disaccharides, 50-51, 330 N,O-Dimethylhydroxylamine, | 44-145 Diselenides.165. 190 1,3-Dimethylimidazolidinone, 309 Disilenes,190 1,3-Dimethyl-2-imidazolidinone, 145 1,4-Disilylation of enones,127 Dimethylketeneimines, 208 Disodiumtetracarbonylferrate, 152-153 Dimethylphosphinothioic anhydrides,145 Disulfides,18 Dimethylphosphinothioyl chloride, 145-146 Dithianes.214 Dimethyl pyrrole-2,5-dicarboxylates, 147 Dithioacetals, 15l, 307 Dimethyl sulfide,222 Dithiocarbonates, 333 Dimethyl sulfide-Dibenzoylperoxide,146 Divinylzinc,68

&l

SubjectIndex

1,6-Diynes,354 DMAB See4-Dimethylaminopyridine (DMAP) N-Dodecylpyridoxal,153 Dodecylsulfate,164 Double Michaeladdition,58

Ethyldiisopropylamine,22, 256 Ethyleneacetals,114 Ethyleneglycol, 156 Ethyl glyoxalatereactions,27 Ethyl hydrogenmalonate,156 Ethyl B-mannopyranoside, 208 N-Ethylmorpholine,246 Ethyl nitrite, 156-157 Ethyl 2-oxo-3-alkenoates, 133 Ethylphenylketene, 306 S-Ethylsulfoximines,5 Ethyl triphenylphosphonoacetate, 757 Ethyl vinyl ketone,208 Etyhylenediaminetetraacetic acid, 199 Evodone,70

o,P-Enaldimines, 182-183 Enaminoketene.93 Endoperoxidation,243 1,4-Endoperoxides, 310 Ene catalysts,159-160 Enediynes,271 Ene reactions.42-43. 136.302 Enol silyl ethers,1 Enol thiol ethers.214 a,p-Enones,186,242, 283 Ferric chloride.158-159 Enones,334 Ferric chloride-Aceticanhydride,159 (E)-1,3-Enynes, 6 Ferric chloride-Alumina,159-160 Enynones,98-99 Ferrier rearrangement, 249 Ephedrine,154-155 Fetizon'sreagent,149-150 Epithio alcohols,308 Flavanones,353 Epoxidation,187, 212 Flavones,353 Epoxides,26,191,365 Fluorene,57 trans-Epoxides, 351 Fluorenone.57 2,3-Epoxyalcohols,110,308 Fluorination.68-69. 272. 287 Epoxy alcohols o-Fluorination,160-161 , 19, 322 Epoxyalkylcoppers, 99 Fluorine, 160 c,B-Epoxyesters,294 Fluorodestannylation, 76 o,B-Epoxyketones,146 Fluoro ethoxysulfates, 76 c,p-Epoxy sulfoxides,78 Fluorohydrins,286 2,3-Epoxy-3-arylpropanols, 169 9-ct-Fluoro-3,11,17-ketosteroids, 160-161 trans-2,3-lEpoxybutaneI -ol, I 9 N-Fluorosultams,68-69 syn-3,4-Epoxybutane-2-ol, 19 N-Fluoropyridiniumsalts,160 2,3-Epoxycinnamyl alcohol,290 N-Fluoropyridinium Epoxysilanes, 223 trifluoromethanesulfonate, 160- 161 Ester cleavage,39 vic-Fluoroalkyl sulfates,76 Esterification,109, 152,178 Formaldehyde-Sodium iodide, 161 Esterinterchange,253 Friedel-Craftsmethanesulfonvlation. Esters,47 201 Etherification,65 Friesrearrangement, 319 3-Ethoxyallylzinc bromide,232-233 Fructose,90 I -Ethoxy-1,3-bis(trimethylsilyloxy)butenel, D-Fructose,291 19 Fulvenes,132 Ethoxycarbonylamino acids,155 Fumarylchloride,246 N(Ethoxycarbonyl)-N,O-bis(trimethylsilyl)- Furanocoumarins, 94 hydroxylamine,155-156 C-Furanosides,311-312 (Ethoxycarbonyl)nitrene, 155-156 Furfuryl alcohol, 90 Ethoxyketene,94 Ethyl 2,3-butadienoate, 109 Gabriel synthesis,305 Ethyl 2,2-dichloro-6-heptenoate, 128 L-Galactose,200

D-Glu p-Glu D-Glu o-Glu a->G t--Glu Gluco Glyca Glyci< Glycc Glycd c-Gly sec4c Glyca C-Gly 9-Gly Glyco o-Glyr Glyco Glyor Glyor Grand Grigl Guan

Hafno (t*Hr a-Hal B.Hd Halo6 Halot Hantz Heck Henci Henrl 3-Hcp It 1,5-H N-Hd Hexa Hexa Hexar Hexar Herar Hexar Herar l( L-Her L-Her Hofm Horm

SubjectIndex D-Glucitol,291 D-Gluconicacid, 139 138 o-Glucono-1,4-lactone, 248 o-Glucosamine, a-o-Glucose.23 200 r--Glucose, Glucosidation,305 Glycals,11l, 200 Glycidicesters,132 162 Glycoaldehyde, Glycol cleavage,294 c-Glycol monoethers,237 sec+ert-|,z-Glycols,92 Glycosidation,119,121,210 312 C-Glycosides, p-Glycosides, 330 Glycosylation,357 o-Glycosyl esterc,2l-22 Glycosylfluorides,l19. 121 Glyoxal,371 Glyoxylate ene reactions,27, 142 Grandisol,28 Grignardreagents,358 Guanine,267 Hafnocene,32 (o-Haloalkenyl)lithiums, 23'l-232 c-Halo carbanions,355 163 B-Halodiisopinocampheylboranes, 218 Halogenation, Halohydrins,163 Hantzschdihydropyridinesynthesis,11 Heck cyclization,248 163 Heneicosadiene, Henry reaction,335 acid, 1633-Heptadecylmonoperphthalic 164 65 1,5-Heptadiene-4-ol, 129 N-Heterocycles, chloride,13 Hexadecyltrimethylammonium triamide,341 Hexaethylphosphoric 164 Hexamethyldisilane, 165 Hexamethyldisilathiane, 269 Hexamethyldisiloxane, Hexamethylditin,42 triamide, 16, 165Hexamethylphosphoric 166 l-Hexenulose,200 l-Hexoses. 200 257 Hofmannrearrangement, 39 Homoallvlbenzenes.

405

Homoallylic alcohols, 83, 209-210, 309 Homoallylicamines,56,247,297 reaction,318 Hosomi-Sakurai Hydration, 197,200 Hydrationof cyanohydrins,295 Hydrazoic acid, 126, 343 Hydridotris(triphenylphosphine)copper hexamer,166 Hydriodic acid, 166 Hydroalumination,137-138 280 Hydroazulenones, Hydroboration,43, 91 Hydrocyanation,103, 130 Hydroformylation,69-70 Hydrogenationcatalysts,250, 265 64 Hydrogenolysis, Hydrogenperoxide,166-167 acid, Hydrogenperoxide-Benzeneseleninic 167 carbonate, Hydrogenperoxide-Potassium 167 fluoride, Hydrogenperoxide-Potassium 167-168 acid, Hydrogenperoxide-Trichloroacetic 168 reagent,13 Hydrogen-transfer 312 cls-Hydroindenes, c-Hydroperoxycarbonylcompounds,243244 Hydrosilanes-Tetrabutylammonlum fluoride, 168-169 Hydrosilylation,33, 135 of 1-alkynes,69 Hydrostannation Hydroxamicacid chlorides,86 hydrochloride,365 Hydroxocobalamin 3-Hydroxycarboxylicacids,364 45 (Z)-4-Hydroxy-l-alkenylcarbamates, 21 2-(c-Hydroxyalkyl)benzothiazoles, p-Hydroxyalkylphenylsulfides,263-264 (Hydroxyalkyl)butenolides, 314 c-Hydroxy acids,149-150 c-Hydroxy carbonylcompounds,21 o-Hydroxycarboxylicacids,41 c-Hydroxy esters,27, 252 o-Hydroxy ketones,92, 366 acids,24 B-Hydroxy-c-amino threo-p-Hydroxy-c-aminoacids,24 B-Hydroxy carbonyl,235 p-Hydroxyesters,294 p-Hydroxyketones,127, 135,148,323 3-Hydroxybutanoic acid, 171

406

SubjectIndex

(R)-3-Hydroxybutyricacid, 171 7 -Hydroxy-2,4-dienoicacids,296 bromide, p-Hydroxyethyltriphenylarsonium r69 Hydroxyisoxazolidines,285 Hydroxy ketones,32 52 Hydroxylactones, Hydroxylaminehydrochloride,170 acid, 170-171 Hydroxylamine-O-sulfonic Hydroxylation, 41, 42, 183-184 Hydroxymercuration,198-199 242 2-Hydroxymethylenecyclohexanone, 241 (S)-2-Hydroxymethylindoline, 139 4-Hydroxy-3-methyl-6-lactones, esters,274 2-Hydroxy-3-oxocarboxylic 2-Hydroxypyridine,152 157 2-Hydroxypyrrolidines, 145 8-Hydroxyquinoline, 55 c-Hydroxysilanes, p-Hydroxysilanes, 223 Hydroxysulphenylation,196-197 vic-Hydroxysulfides,196 1-Hydroxy-1-vinylacetals,312 Hypoioditereaction,151,174 154 Imidazolidinones, Imines, 175-176,273, 317 20'7-208 2-Iminooxetanes, (-)-FK-506,85 Immunosuppressant Indane,57 Indanone,57 Indenols,234-235 Indole alkaloids,254 329 Indolizidinones, Indolizines,219 308 1,2-cyclothiophosphate, rnyo-InositolIodination,70,172 lodine, 172-1'73 Iodine/Alumina, 173 Iodine-Copper(II)acetate,173 Iodine-Hydrogenperoxide,1'13-l'l4 Iodine-Mercury(II) oxide, 174 178 Iodoacetalization, 173 1-Iodo-1-alkynes, IodobenzenedichlorideIPhenyliodine(III) dichloridel,174-175 Iodocyclization,30 39 Iodocyclohexenes, 258 Iododecarboxylation, Iodofluorination,287 o-Iodo ketones,70

30 2-(1-Iodomethyl)oxetanes, 30 2-(1-Iodomethyl)oxiranes, Iodoniumperchlorate,51 175 tetrafluoroborate, Iodosobenzene 178 N-Iodosuccinimide, 175-178 Iodosylbenzene, resins,178 Ion-exchange B-Ionone,163 Iron3* -Montmorillonite, 178-179 Isatoicanhydride,11 Isobutane,198 Isobutene,159 144 Isocyanates, Isoeucommiol,198 Isomerization,365 Isomerizationof alkYnes,135 Isopropenylesters,124 2,3-Isopropylidene-2,3-dihydroxy-l'4(DIOP)' bis(diphenylphosphine)butane 179-180 1,2-O-Isopyrrolidine-o73 glyceroylmethYlPhosPhonate, Isothiazoles,170 87 Isoxazoles, 78 2-Isoxazolines, 148 Isoxazolines,86, Itaconicacids,179 (+)-Ivalin,182 Jonesreagent,92 Julia synthesis,45 hormone,26 (-)-C-16-Juvenile Ketals,222 317 Ketenealkyl silYlacetals, Ketenesilyl acetals,155 a-Keto acids,149-150 B-Keto acids,196 p-Keto amides,196 Keto aldehydes,316 255 1,4-KetoaldehYdes, o-Keto esters,252 B-Ketoesters,206 Ketones,1'76,292 251 meso-Ketones, 53 Ketopantolactone, Ketoximes,157 cyclizations,128 Kharasch-type 99-100' 159 Knoevenagelcondensation, Lactams.176,199

B-Lactam (S)-Laax (S)-Lacr Lactim et Lactone r Lactones b-Lactorx 1-Lacton Lactoniz Lanthan Lasubirr Lawesso Lead(ll ) Leucine L-t-L€uc Lineatoo 2-Lithior N-Lithro l8lLithium. Lithium Lithium Lithium pen Lithium l&r Lithium Lithium 86 Lithium Lithium atE,

Lithium chlc Lithium Lithium Lithium Lithium Lithium Lithium Lithium Lithium Lithium Lithium lm Lithium Lithium Lithium Lithium Tct Lithium

SubjectIndex

r ) ' .: rnf [)loP).

lc

-:

) - . , i 1 .1 5 9

Nl

Lithium tri-sec-butylborohydride'192-193 B-Lactams,82, 150, 181,207, 216' 279' 370 193 Lithium triethYlborohYdride, (S)-Lacticacid, 181 193,222 Lithium trisiamylborohydride, (S)-Lacticaldehyde,181-182 54 2,6-Lutidine, Lactim ethers.337 263 Lactonering exPansion, McMurry coupling, 316-317 Lactones,306 95 Macrocyclization, b-Lactones,306 131 Macrolactonization, 1-Lactones,306 Magnesiumanthracene,194 Lactonization, 105, 245-246 Magnesiumbromide, 194-196 208 LanthanidecatalYsts, Magnesiumchloride-Sodiumiodide, 196 LasubineII, 222 231 Magnesium2-ethoxYethoxide, Lawesson'sreagent,37, 329 194 Magnesium-Methanol, Lead(II) bromide/Aluminum,182 Malonyl radicals,73 Leucine.149 Mandelicesters,125 L-r-Leucine,r-butylester, 182-183 Manganese(III)acetate,71 Lineaton.28 Manganese(III)acetate-Diphenyldisulfide, 228 2-Lithiothiophene, t96-197 N-Lithio-N,N'N'-trimethylethylenediamine, Manganese(II)bromide,234 183-184 dioxide, 197-198 Manganese Lithium, 184 Mannichcyclization,161 Lithium acetylides,173 o-Mannitol. 139.291 148 Lithium alkoxydimethylzincate, reductions,32 Meerwein-Ponndorf-Verley Lithium aluminumhydride-Bis(cyclolMenthol,83 184-185 pentadienyl)nickel, 3 Menthyl (S)-3-(2-pyridylsulfinyl)acrylate, Lithium aluminumhydride-Lithiumiodide' 305 2-Mercaptoalkanols, 185 Mercury,198 27 Lithium/ammonia. Mercury(Il)acetate,198-199 amide' 185Lithium N-benzyltrimethylsilyl Mercury(Il) chloride,200 86 Mercury(Il) sulfate,200 226 Lithium bis(trimethylsilyl)cuprates, 288 O-(Mesitylsulfonyl)hydroxylamine' Lithium borohydride-Chlorotrimethylsilortho -Metallatio n, 23| ane,186 141 Methacrolein, Lithium borohydride-Europium(III) anhYdride,201 Methanesulfonic chloride,186-87 chloride,252 Methanesulfonyl 271 Lithium t-butoxide, 201 a-Methoxyallene, 187 Lithium t-butylhydroperoxide, anhydride,20 p-Methoxybenzenetellurinic 187 Lithium cyclohexylisopropylamide' 85 B-MethoxyboranePane, 188 Lithiumdiethylanlide. 356 (E)-l-Methoxy-1,3-butadiene, Lithium diisopropylamide,188-189 24'7-248 Methoxycarbonylation, 226 Lithium dimethylcuprate, 58 2-Methoxycarbonyl-2-cyclohexenone' 190 Lithiumdiselenide, 74 2-Methoxycarbonylcyclohexenone, 207 Lithium hexamethyldisilazane, 201B-Methoxydiisopinocampheylborane' 3 Lithium hexamethyldisilazide, 202 Lithium N-lithiomethyldithiocarbamates, alcohols'201-202 syzr-B-Methoxyhomoallyl 190 201 (Methoxymethyl)allene, Lithium naphthalenide,61, 99, 190,222 amides,144 N-Methoxy-N-methYl Lithium nitrate. 367 (E,Z)-1-Methoxy-2-methYl-3191-192 Lithium tetraalkylcerates, ene' 202 (trimethylsilyloxy)1,3-pentadi Lithium tetramethylpiPerideisocyanate,259 2-Methoxy-l-naphthyl 192 TetramethylthYlenediamine, acid, 308 (R)-( - )-o-Methoxyphenylacetic 239 Lithium trialkylzincates,

40E

SubjectIndex

203 Methyl (Z)-3-phenylsulfonyl-2-propenoate, B-Methoxy-1-phenylthioketones, Methoxy(phenylthio)methane,202-203 210 Methoxyselenenylation, 29-30 Methyl phenylthioacetate, 113 4-Methoxy-2,2,6,6-tetramethyl(S)-1-Methyl-2-[(piperidinyl)methyl]1oxopiperidiniumchloride,204 pyrrolidine,314 B-Methoxy-2-trimethylsilylborolane, (1S,2S)-( 8 + )-N-Methylpseudoephedrine, 8 Methylaluminum bis(4-bromo-2,6-di4N-Methylpyrrolidin-2-one, 90 butylphenoxide,205 N-Methyl-2-pyrrolidone, 153 Methylaluminumbis(2,6-di+-butyl-4Methylsilyltrifluoromethanesulfonate, 177 methylphenoxide), 141,204-205 Methylsulfenyltrifluoromethanesulfonate, Methylaluminumbis(2,6-diphenylphen210-211, oxide) 205 Methylthioacetonitrile, 102 tert-N-Methylamines, 56 Methylthiomethylethers,146 Methylarenes,126 Methyl p-tolyl sulfoxide,211 N-Methylation,280 Methyl ( - )-triacetoxyshikimate, 3 Methyl bromoacetate,325 Methyl(trifluoromethyl)dioxir ane,212 3-Methyl-2-butenylzinc bromide,239 Mevinic acids.263.272 Methyl cyanoformate,206 Michaeladditions,15, 157, 213-214,313l-Methylcyclohexanol, 99 314 N-Methyl-2-dimethylaminoacetohydroxamicMitsunobuinversion,96, 200 acid.206 Mitsunobureagent,352 Methyl c:dimorphecolate,29 Molybdenumcarbonyl,212-213 (ct-Methyldiphenylsilyl)alkyl ketones,1 Monensin.194 (E)-c-Methyl-o,B-enals, 338 Monoacetalization, 371 6-Methylenebicyclo[3. 3.0]octane-2-ones, 32 Monoperphthalicacid, 163 Methylene-2-cyclohexenes, 91 Montmorillonite,213-214 Methylenecyclopentenones, 54 MontmorilloniteKSF,214 Methylenecyclopropanes, 32, 184 Mukaiyamaaldol condensation, 319 Methylene-1,3-dicarboxylic acid, 184 Mukaiyama'sreagent,85 o-Methylene-B-hydroxy-1-alkoxyketones, 109 1-( 1-Naphthyl)ethylamine, 215-216 (R)-(- )-(l-Naphthyl)ethyl o-Methylene-B-lactones, 243 isocyanate. Methylglucopyranoside, 349 256 Methyl glyoxalate,27 Nazarovreagents,58, 74 alcohols,75 Nef reaction,320 B-Methylhomoallyl Methyl hydrogenmalonate,207 Nickelboride.216 Methyl (R)-3-hydroxybutyrate, Nickel carbonyl, 216-217 207 MethylketeneN-benzylimine,208 Nickel(II)chloride/ZinclPyridine, 217 Methylketeneimines, 207-208 Nickel(Il) cyanide,72-73 Methyl ketones,339 Nileprost,245 Methyllithium,208 N-Nitration, 141 Methyl maleate,59 Nitration, 101 Methyl (E)-4-methoxy-2-oxo-3-butenoate, Nitriles, 130, 176,253,292, 300 208-209 B-Nitro alcohols.335 N-MethylmorpholineN-oxide, 241 Nitro aldol reaction,335 Methyloxidocopperlithium, 226 Nitroalkenes,339 Methyl 2,4-pentadienoates, 207 Nitroarenes,278,295 endo -6-Methyl-5-phenylbicyclo[2.2.2]oct-2- 2-Nitrobenzenesulfenyl chloride,217-218 ene, 300 2-Nitrobenzenesulfinyl chloride,218 Methylphenylsilane, 32-33 2-Nitrobenzenesulfonyl chloride,275 p-Methylphenylsulfonyldiazomethane, p-Nitrobenzenesulfonyl 209 peroxide,218

N-(P-! :l"[

2-Nitr( Nitrog Nitroo l-Nitn N-Nitr Nitroe Nitros Nitrox NMP. Norca (ls.2R Norp.v Nozah Nuckr

2,GOc Octah Octocl Orellil Organ Organ Organ Organ Orgarr Orgar Orgarr Orgarr Organ Organ Orgarr Orgarr Orgarr Osmiu Osmiu pi Oxaza Oxazq Oxazd cis-Or 2-Oxu Oxetal Oxidat Oxidat Oxidat Oxidat Oxidat Oxime Oxirao 4-Oxo

SubjeclIndex

rd O:-

!li:

lf

I

i t:

I !

N-( p-Nitrobenzylidene)benzenesulfonamide,218-219 2-Nitrocycloalkanones, I 67 Nitrogendioxide,219 Nitrones.273. 295 1-Nitro-2-(phenylthio)ethylene, 219 N-Nitrosation,219 Nitrosoarenes, 144 Nitrosolactams. 219 Nitroxides.144 NMP, seeN-Methylpyrrolidin-2-one Norcarboxylicacids,40 ( I S,2R-)Norephedrine, 219-220 Norpyrenophorin,188 Nozaki reaction.95 Nucleopeptides, 218 2,6-Octadienoic esters,185 Octahydronaphthalene, 2i2 Octosylacid, 116 Orellin, 344 Organoaluminumreagents,221 Organoboranes, 221 Organoceriumcompounds,221 Organocopperreagents,Z2l-229 Organocopper/Zincreagents,229-230 Organolithiumreagents,230-231 Organomagnesium/zinc reagents,232-233 Organomanganese(II) halides,234 Organoosmiumcompounds,236 Organosilanes,236-237 Organotinreagents,237-238 Organotitaniumreagents,238 Organozincreagents,lC/l, 238-240 Osmiumtetroxide,240-241 Osmiumtetroxide-Dihydroxyphenylborane,241 Oxazaborolidines, 241 Oxazepines,105 Oxazolidines,chiral, 242 cr's-Oxazolidin-2-ones, 259, 265 2-Oxazolines, 286 Oxetanes,289, 306 Oxidationof phenols,18 Oxidativecontractionof glycals,g6 Oxidativedealkylation,56 Oxidativedecarboxylation, 176, 293 Oxidativedemethylation,71 Oximes,292,317 Oxiranes,98, 306 4-Oxo aldehvde.71

409

2-Oxo-3-alkenoic acids,133 2-(Oxoalkyl)triphenylarsonium bromides, 242 2-Oxoglutaricacid, 153 O x o n e .1 4 4 . 2 1 8 a-Oxo triflates,177 cls-Oxyamination, 265 Oxychlorination,102 Oxygen,singlet,243 Oxytellurinylation,19-20 a-Oxy-o-xylylene, 59 Ozone,243-244 Palladium.245 Pafladium(Il)acetate,t13, 245-247 Palladium(II)acetate-1,3-Bis(diphenylphosphino)propane,247-248 Palladium(II)acerate-Triphenylphosphine, 248 Palladium/Charcoal. 13 Palladium(II)chloride,248-249 Palladium(II)chloride-Benzoquinone. 249 Palladium( tI) chloride-Coppei1ll.1 chloride. 249-250 Palladium(II)chloride-Salicylidenethvlenediamine(salen),250 Palytoxin,186 R-( - )-Pantolactone, 53 PCC, seePyridiniumchlorochromate Pellitorine,35l Penicillanicacids,39 Pentacarbonyl(trimethylsilyl)manganese, 235 2,4-Pentadienoates, 156 Pentaff uorobenzenesulfenyt isocyanate,15 Pentalenene, 89-90, 114 (R,R)-2,4-Pentanediol, 251, 287 4-Pentenyloxymethyl chloride,251-252 Peptidesynthesis,145-146,149 Peracids,274 Periodinaneof Dess-Martin, 52,252 Petersonreaction, 102, 202 Phase-transfercatalysts,252-253 Phenacyldibutyltelluronium bromide,29g Phenanthrenequinone, 254-Z5S Phenanthrenes, 47 Phenanthridines, 189 9-Phenanthrols. 188 Phenethylamines, 253-254 Phenolannelation,66 Phenols, 98,167,173

410

SubjectIndex

Phosphonylation, 36 Phosphoricacid, 266-267 Phosphorusoxychloride (Phosphoryl chloride),267 Phosphoruspentoxide,267 Phosphorylation, 112 Photochemical [2+2]cycloaddition,7 Photo-Claisen rearrangement, 107 [2 + 2]Photocyclization,346 Photocyclization of arylimines,47 Photo-Friesrearrangement, 107 dehydrogenation, Photosensitized 353 Physostigmine alkaloids,127 Picrates,268 Picricacid,268 Pinacol,269 Pinacolcondensation, 282 Pinacolone.269 Pinacols,317, 366 Pinene,221 258 157 2-Piperidines, Phenyliodine(III)diacetate,258 Phenyliodoniumbis(phenylsulfonyl)methyl- Piperidines,20, 44, 1,61 268 1-Piperidino-3,3-dimethyl-2-butanol, ide,259 2-Piperidones, 262 Phenylisocyanate,259, 303 Pivaldehyde,181 Phenyl isocyanidedichloride, 259-260 Pivalonitrile,79 8-Phenylmenthol, 125, 260-261 esters,39 Pivaloyloxymethyl 8-Phenylmenthylphosphonoacetate,Zffi Platinum(IV) oxide, 268-269 chloride,246 5-Phenyl-2,4-pentadienyl Polyethyleneglycol, 274 2-Phenylpropanal, 309 acid, 51 Poly3-hydroxybutyric Phenylselenol esters,329 Polyketides,46 Phenylselenophosphonic dichloride,261 dichloride,93 Polyoxochromium Phenylselenoquinones, 18 Polyphosphoric acid trimethylsilylester, 4-(Phenylsulfonyl)butanoic acid,262 269 nes,264 3-(Phenylsulfonyl)-ALisoxazoli Polypropionate1,3-diols,224 284 Phenylsulfonyl methyl selenoketone, 4-Polystyryltritylamino acids,359-360 1-Phenylsulfonylpropanol-2, 262-263 POM ethers,21 c-Phenylthiocycloalkanones, 265 Potassium,269 o-(Phenylthio)ethers,6l 270 Potassium3-aminopropylamide, syn-o-Phenylthio-B-methoxy alcohols,192Potassiumt-butoxide,271-272 193 Phenylthiomethylenetriphenylphosphorane,Potassium-l8-Crown-6,270 Potassiumflioride,272 263 Potassiumfluoride-l8-Crown-6.272-2'/3 Phenylthiomethyl(trimethyl)sil ane,263-264 Potassiumfluoride-Hydrobromicacid, 273 Phenylthionitrileoxide, 264 Potassiumhexamethyldisilazide,286 (Phenylthio)nitromethane, 264-265 Potassiumoxomonosulfate, 212 carbonyl,203 1-Phenylthio-p,'y-unsaturated 273-274 Potassiumpermanganate, Phenylvinyl sulfoxide,115 Potassiumperoxymonosulfate,278 Phosgene,265 Potassiumpersulfate,274-275 Phosphines,chiral, 265-266 Potassiumsuperoxide,275 256 Phospholipids, 195 Potassiumtri-sec-butylborohydride, 348 Phosphoniosilylation,

m-Phenoxybenzyl alcohol,145 Phenylarenedithiocarboxylates, 150 N-Phenylation,352 Phenylboric acid, 254-255 S-Phenylcarbonochloridothioate, 255 1-Phenylcyclohexene, 241 (N-Phenyl)dialkynylimines, 259 Phenyldichlorophosphate*Sodium iodideDimethylformamide,255 Phenyldichlorophosphite, 256 enol ethers,127 1-(Phenyldichlorosilyl)silyl Phenylethylisocyanate,256 N-Phenylfluorenyl-l-alaninal, 49, 50 group, 49 Phenylfluorenyl (25,3S)-3-Phenylglycidol, 341 Phenylglycine, 153 o-2-Phenylglycinol, 256-257 Phenylhydroxamic acid, 285 Phenyfiodine(III) bis(trifluoroacerate), 257-

Pro Pro 1.1 Pro Pro B.P Pro Pro Pro Pro Pro Pro Pro Psc Psc Psc Psc Psc Pun

S'r $r $n $n $n $n $n $n $n $n 2-h Sn $n Pln

Qui

Qul Qur Qur p-Q Qul Qul Quir o-Q

Ran Ran Red Red Red Red Red

SubjecrIndex

D

7

Prolines,24 Propane-1,3-dithiol, 114 1,3-Propanedith iol, 242 Propargylicalcohols,316 Propenylcuprate, 224 es,224,270 B-Propiofacton Propyne, 124 Propynylethers,270 Prostaglandins, 45, 199 Protection, 251-252 Protectionof amino grotps, 21,7-2lg Protodesilylation, 7 Proton Sponge,364 Pseudo-o-o-glycopyranose, 23-24 Pseudoguaianolides, 1l7 Pseudopterosin A, 66 Pseudo-B-r--pyranose, 24 Pseudosugars,23 Pummererrearrangement, 2,11,269 Pyranosides,24S-49 Pyraziniumchlorochromate,2il5-276 Pyrazole,344 Pyridinecarboxylic acids,160 Pyridinesynthesis,170 Pyridiniumbromideperbromide,276 Pyridiniumchlorochromate , 5j, 66,276 Pyridiniumfluorochromate,57 Pyridiniumpoly-(hydrogenfluoride), 121 Pyridiniump-toluenesulfon ate, 7g_79, 276 2-Pyridones,160 Pyridoxal,153 P y r r o l e s , 8 11,4 7 Pyrrolidines,44, 132 Quina alkaloids.277 Quinazolines,87 Quinidine.277 Quinine,277 p-Quinones,257 Quinonemethides,369 Quinonemonoacetals, 205 Quinones,173.294 a-Quinones, 18,361 Ramburg-Backlundreaction,271 Raneynickel, 184,278, 329 Reductionof o,B-acetylenic esters,194 Reductionof an enone. 137 Reductionof carbonylcompounds,333 Reductionof ozonides.44 Reductiveacylation,206

4Il

Reductive alkylation, 27-28 Reformatsky-type reaction,323 Reimer-Tiemannformylation,84 Remotechlorination,174 Resolution,67, 135,256 Resorcinols,60 Retro-Diels-Alderreactions,100 Rhodium(Il) benzoate.279 Rhodium(II) carboxylares, 278 -280 Ring expansion ,82, 174,292 Ritter reaction,197.339 Ruthenium(III)chloride-Tributylphosphite, 280-281 Rutheniumtetroxide,281 SADB see(S)-(- )-Amino-2-(l-methoxy-lmethylethyl)pyrrolidine (SADp) Salicyclaldoxime, 86 Samarium(Il)iodide,282-284 Samarium(II)iodide-TetrahydrofuranHexamethylphosphoric triamide,2g4 Samarium(III)chloride.282 S a r c o p h y tB o l, 3 1 7 schwartzreagent,80 Secogalioside, 88 Secoiridoids. 88 Secologanin,88 Selenabicyclics, 42 Selenaldehydes, 42 Selenium.165 Selenium(IV) oxychloride, 89 Selenoacetals, 101 Selenocarbonyl compounds,261 Selenocyanogen, 284 Selenoimidates, 330 Selenoketones. 284 Seleno-Pummerer rearrangement, 336 SEM ethers,298-299.344-345 Semicarbazide, 284-285 Sensitizers, 37 (S)-Serine.24 Sharpless epoxidation,322 Shikimicacid.3 Shodomycin,855 Silica,285 Silicon(IV)fluoride. 286 Siloxyalkynes, 60 Siloxymethylation, I l8 Silverfluoride/Calciumfluoride.2g7 Silveroxide, 369 Silverperchlorate,127

4t2

SubjectIndex

316 Silvertrifluoroacetate. Silylation,107 p-Silylaldehydes,69 Silylcobaltcarbonyl,118 Silylcyclopropanes,344 178 N-Silyldihydropyridines, 334 B-Silyl-c,B-enals, Silylenolethers,51 Silylformylationof alkynes,334 Silyl keteneacetals,19, 178 o-(Silyloxy)allylethers,61 Simmons-Smithreagent,287,324 Singlet oxygen, 294 356-357 Smilesrearrangement, Sodium aluminum silicates,367 Sodium anthracenide,288-289 150 Sodiumarenedithiocarboxylates, Sodiumazide,106 289 Sodiumazide-Dimethylformamide, ate, 289 Sodium benzeneselenol Sodium benzyloxide,289-290 Sodiumbis(2-methoxyethoxy)aluminum hydride, 290 Sodiumborohydride,290 Sodiumborohydride-Cerium(II)chloride, 291 Sodium borohydrideTrifl uoromethanesulfonicacid, 291 Sodiumborohydride-Zirconium(IV) chloride,292 Sodiumbromite, 292 Sodium dichloroisocyanurate,292-293 SodiumO,O-diethylphosphite,293 SodiumO,O-diethylphosphorotelluroate, 293 Sodium-Ethanol.288 Sodiumhydrogenselenide,293 Sodium hypochlorite, 293 Sodiummolybdate(Vl)-Hydrogen peroxide,294 Sodiumnaphthalenide,165 Sodiumperiodate,294 294 Sodiumphenylseleno(triethoxy)borate, Sodium(potassium)amide, 288 Sodiumtetraborate,295 Sodium tetracarbonylhydridoferrate,295 Sodiumthiosulfate,134 Sodiumtungstate,295 Sorbic acid, 296 73 D-erythro-C8-sphingosine, Sphondin,94

Squaricacid,296 Staudingerreaction, 360 Steglichesterification,131 Stilbenes,47 Streckeramino acid synthesis,103 170 Streptonigrinoids, Styrenes,156-157 C-Sucrose,96-97 o-Sulfenyl aldehydes,202-203 esters,19 o-Sulfenyl-B-hydroxy Sulfides,218 o,B-Sulfinylepoxides,211 2-Sulfinylindole,127 3-Sulfinylindole,126-127 de, 297 N-Sulfinyl-p-toluenesulfonami Sulfonylhypohalites,218 Sulfoxides,71, 218,292 Sulfoximines.135.288 Sulfur,297 329 Swainsonine, TanshindiolB, 363 Tartaricacid, 103 Taxols,152 TDA-I, 356-357 Tebbenitriles,79 Tellurium.293.298 298 Tellurobenzaldehyde, Telluroniumylides,298 308 1,4,5,6-Tetraacetyl-nyo-inositol, 2l 2,3,4,S-Teta-O-benzyl-o-glucopyranose, Tetrabis(triphenylphosphine)palladium, 1,27 Tetrabutylammoniumfluoride, 27, 75, 304 fluoride-HexaTetrabutylammonium methylphosphorictriamide, 298-299 hydrogensulfate,73 Tetrabutylammonium Tetrabutylammonium (tricarbonylnitrosyl)ferrate,299 118 Tetracarbonylmethylcobalt, Tetrachlorophthalicanhydride, 300 300 2,6,9,l0-Tetracyanoanthracene, Tetracyclization,12 Tetraethylammoniumacetate,240-241 Tetrafluorophthalicanhydride, 300 Tetrahalomethane,182 Tetrahydrobenzopyrans,301 Tetrahydrofurans,60, 227 188 Tetrahydropyranylacetic, 353 Tetrahydropyranylation, Tetrahydropyranylethers, 168

Te

Tet

l.: Tet

2.

Te Te Te

l.l Tc Tc

Tc

Tt Th Th [2 Th Th Th Th Tt TI TI tTt TI TT Tt TI TT TI TT TI TI TI

Th L . ,

Tir Tx Tir Til

Tir

SubjectIndex

F-

il. ln,'.c. ll

h;r. -i. l,q 6 :+r [air

9

I

--i

413

Tetrakis(triphenylphosphine)palladium(0),Tin(II) trifl uoromethanesulfonate300-304 Tributyltin fluoride, 314_315 Tetrakis(rri-p-tolylphosphine)palladium(0),Titanacyclobutanes, 79 l5l Titanium(0),315 2,2,3,3-Tetr amethylbutane, 19g Titanium(III) chloride-potassium / GraphTetramethyldiamides, 46 ite,316-317 2,2,6,6-Tetamerhyl-2,6-disilapiperidine, Titanium(III) chloride-Sodium 304-305 cyanoborohydride, 317 Tetramethylethylenediamine, 16 Titanium(III) chloride-Zinc/coppercouple, Tetramethylorothocarbonate. 305 J t I Tetramethylsuccinamide, 46 Titanium(IV) butoxide/Copper(I)chloride, l, 1,3,3-Tetramethylurea, 305 316 Tetraphenylantimony iodide, 306 Titanium(IV) chloride,317-320 Tetraphenylantimony trifluoromethanesul_ Titanium(IV) chloride-Lithiumaluminum fonate,306 hydride,320-321 Tetraphenylporphyrine, 243 Titanium(IV) chloride-Magnesium, 321 -B-o-galactopyranosyl_ Titanium(IV) 2,3,4,6-Tetrapivaloyl chloride-Titanium(IV) amine,103,307 rsopropoxide,321-322 Thallium(I) carbonate,47 Titanium(IV) isopropoxide,322 Thallium(III) nitrare,86 TMEDA, seeTetramerhylethylenediamine Thienamycin,207 p-Toluenesulfonyl azide, 323 [2-Thienyl(cyano)copper]lithium, 228 (N)-Tofuenesulfonyl)phenylgly cinol, 242 Thiiranes,305 o,p-Tolyl sulfoxide,2l 1 Thioacetals, l0l.2l4 N-Tosylimines, 297 Thioacylsilanes, 97 Transacylation, 206 Thioaldehydes, 97 Transamination,l3 Thioamides,275 Transesterification. 84 Thioesters.121 Transferhydrogenation,13,27g Thioethers,166 Transylidation,35I 1-Thio-B-o-glucopyranoside, 210 3,4,6-Tri-O-acetyl-B-o-glucopyranosyl Thiogfucosides,210-2ll chloride,305 Thioglycolates,113 Trialkylchlorosilanes, 323 Thioimidates,331 Trialkylsiloxyalkynes, 60 Thiolaceticacid, 307-308 o-Trialkylsilylpropionaldehyde, 338 Thiolactones,165 Trialkylstibines,323- 324 Thiols. 37 Trialkyltin hydrides,324 Thionolactones, 332 Tribenzyl-o-glucal, ti6 Thiophosphorylchloride,30g Tributylarsine,325 Thiosalicylamides, 187 Tri butylphosphine-Zinc, 325 Thiourea.243 2-(Tributylstannyl-4,4-dimerhyl-2-oxazoline, Thiourea-Titanium(IV)isopropoxide, 124 309 (Tributylstannyl)methyl ethers,60 Thioxanthen-9-ones, 187 Tributylstibine,325 I--Threonine.3 Tributyltin hydride, 69, 325-333 Tin(II) chloride, 182,309-310 Tributyltin hydride-Tributylphosphine Tin(IV) chloride, 142.3tt-313 oxide, 333 Tin-Aluminum. 309 Tributyltin hydride-Triethylborane, 333 Tin(II) chloride-Chlorotrimethvlsilane. 1,4,7-Tricarbonyl compounds,203 3 l 0 - 3 1I Tricarbonyl(5,8-dimethoxynaphTin(II) trifluoromethanesulfonate, thalene)chromium. l6 31 3 - 3 1 4 Tri-r,r-carbonylhexacarbonyldiiron, 334

414

SubjectIndex

Tricarbonyl(naphthalene)chromium, l6 Tri-to-carbonylnonacarbonyltetrarhodium 334 [tetrarhodiumdodecacarbonyl], Tricarbonyl(triphenylphosphine)nickel,

334-33s vic-Tricarbonylcompounds,253-254 Trichforoethylene, 270 Trichloroisopropoxytitanium, 335-336 Trichloromethyltitanium, 238 3-(2,4,6-Trichlorophenoxyacetamido)pyridine, 356 1,1,1-Trichloro-3,3,3-trifluoroacetone, 336 Tricyclicergolines,35 Tricyclohexylphosphine, 31 Tridachione,102 Trienals,133 1,3,5-Trienes,246 N-1-Triethylallylimines, 75 Triethylamine,336 Triethylammoniumbis(catecholato)alkenylsiliconates,336-337 Triethylborane , 32, 337 Triethyloxoniumtetrafluoroborate,337-338 Triethylsilane,15 Triethylsilane-Titanium(IV) chloride,338 Trifluoroaceticacid. 338-339 vic-Trifluoroacetoxysulfides, 196 'frifl uoromethanesulfonic acid, 339 Trifluoromethanesulfonic anhydride,339340 Triffuoromethylation, 340,341 N-p-Trifluoromethylbenzylcinchoninum bromide,340 Trifluoromethylbromide,340 Trifluoromethyltrimethylsilane, 341 1,1,1-Trifluoro-2-propanone, 212 5-Trifluorouracil, 340 Trifluorperacetic acid, 148 Tri(2-furyl)phosphine, 33 1,2,3-Trimethoxybenzene, 269 Trimethoxymethylsilane, 7- 8 Trimethoxysilane-Dilithium 2,3-butanediolate,341 Trimethylaluminum,140,238. 341-342 5-Trimethylcyclohexenone, 89 Trimethylgermanium halides,342 Trimethyl orthoformate, 342 2-Trimethylsiloxy azides,16- 17 1-Trimethylsiloxy-1-phenylethylene,129 2-Trimethylsilyl-3-alkylindenols, 235 Trimethylsilyl azide, 342- 343

343 1-Trimethylsilylbutadienes, 344 Trimethylsilyldiazomethane, 247 1-Trimethylsilyll-3-dienes, Trimethylsilylenol ethers,177 chloride, B-(Trimethylsilyl)ethoxymethyl 344-345 (Trimethylsilyl)ethoxymethyl ethers,298 (2-Trimethylsilylethylidene)tris(2-methylphenyl)phosphorane, 345-346 2-Trimethylsilylethylidinetriphenylphosphorane,345 346 Trimethylsilylisoselenocyanate, Trimethylsilylketeneacetal,129 chloride, Trimethylsilylmethylmagnesium J45

83 Trimethylsilylmethylpotassium, O-Trimethylsilylcyanohydrins,346 I -(Trimethylsilyloxy)-2-alkoxycarbonylcyclopropanes,272 346 2-Trimethylsilyloxy-1,3-butadiene, Trimethylsilyltriflate,66, 102, 108 Trimethylsilyltrifluoromethanesulfonate, 346-350 I -alkenes,350 2-Trimethylstannyl(E)-3-Trimethylstannyl-2-alkenoates, 350 (Trimethylstannyl)copper(I)-Dimethyl sulfide,350 (Trimethylstannyl)copper reagents,350 Trimethylstannyllithium, 347-348 ethylide,351 Triphenylarsonium ylides,350-351 Triphenylarsonium Triphenylbismuthdiacetate,352 37 Triphenylmethanol, Triphenylmethylchloride,359-360 halideTriphenylmethylphosphonium Potassiumt-butoxide,352 tetrabromide, Triphenylphosphine-Carbon 352 Triphenylphosphine-Diisopropyl azodicarboxylate,352-353 hydrobromide,353 Triphenylphosphine 2,4,6-Triphenylpyrylium tetrafluoroborate, 353 l'-binaphthol, 136 3,3'-Triphenylsilyl-1, Triplex catalysis,129 Trisaccharides, 5I Tris(dibenzylideneacetone)dipalladium (chloroform),353-354 Tris(diethylamino)sulfonium 169 difluorotrimethylsilicate,

Tris

Tris

Tris Tnl

Tris

c.o

Trisl Tng l.l-

Trit( N.T Tnn Trin Tnn Tntr Tntr

Trr

Tuh Tvlo

Ug Ulln Ulln Ultr Ultr o.p

9.r

6.e o.p o.$ Urr Urc

Van

Ven Veti

(-) Vin

SubjectIndex Tris(diethylamino)sulfonium difluorotrimethylsiliconate, 355 Tris(6,7,7,8,8,8-heptafl uoro-2,2-dimethyl3,5-octanedionato)europeum orpraseodymium, 355 Tris(6,6,7,7,8,8,8-heptafl uoro-2,2-dimethyl3,5-octanedionatoytterbium, 356 Tris[2-(2-methoxyethoxy)ethyl]amine, 356358 Tris(2-methylphenyt)phosphine, 345 C,O,O-Tris(trimethylsilyl) keteneacetal, 368 Tris(trimethylsilyt)silane, 358-359 Tris(triphenylphosphine)nickel(0), 359 1,1,2-Trisubstituted dihydronaphthalenes, 230-231 Triton B, 144 N-Tritylaminoacids,359-360 Trityl chloride,359-360 Trityl chloride-'iin(Il) chloride,360 Trityl ethers,168 Trityl hexachloroantimonate, 15, 360-361 Trityl perchlorate,361-362 Tryptamine,254 Tubercidin.357 Tylophorine,260 Ugi condensation, 307 Ullman ether synthesis,145 Ullmann reactions,99 Ultrasound.363 Ultrasoundactivation,197 0,8-Unsaturatedacids,368 amides.247 B,1-Unsaturated 6,e-Unsaturated epoxides,8l o,B-Unsaturated esters.325 c,B-Unsaturatednitriles,325 Uracils,22 Urea, 154 Vanadyltrichloride(Vanadium oxytrichloride),364 Verrucarol,9 Veticadinol,160 (-)-Vetivone,89 Vinvl acetate.7l

41S

Vinylallenes,57 Vinyl bromide,225 Vinyl(chloro)silanes, 364 Yinylcuprate, 224 Vinylcyclobutanols, 346 Vinyl cyclobutylamines, 130 Vinylcyclopropylsilyl ethers,l0g 2-Vinyl-1,3-dioxolan-4-ones, 31_32 Vinyl ethers,347-48 Vinyl(fluorodimethyl)silanes, 364-365 Vinyl Grignardreagents,133 Vinyl halides,118 Vinyliodonium salts, 176-77 Vinyliodoniumtetrafluoroborates, 6, 176_ 177 Vinylketenes,60 Vinyllithiums,4l,225 Vinylsilanes,202 Vinyl sulfones,210 Yinyltin,225 Vitamin B,, (Hydroxocobalamin hydrochloride),365 Vitamin E, 54 Wilkinson'scatalyst,91 Williamsonsynthesis,77, l16 [1,2]Wittigrearrangement, 134 [2,3]Wittigrearrangement, 61, 165,210 Wittig-Horner reactions,73-74, 260_ 261 Wittig reactions,157,298, 325,3Sj Wittig-Smilesreaction,352 Xanthen-9-selonones, 187 Ytterbium(0),366 Zeolites,367 Zinc chloride,368-371 Zinc(II) chloride,103, 139, 152-153 Zinc borohydride,36T Zinc bromide,368 Zinc-Coppercouple,367-368 Zinc powder,325 Zirconiumsulfate,371 Zirconocene,32