资源描述：
《Convenient Synthesis of 2-Azido-2-deoxy-aldoses by Diazo Transfer》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、HELVETICACHIMICAACTA-Vol.74(1991)2073194.ConvenientSynthesisof2-Azido-2-deoxy-aldosesbyDiazoTransferbyAndreaVasella*andChristianWitzigOrganisch-ChemischesInstitut,UniversitatZurich,Winterthurerstrasse190,CH-8057ZurichandJose-LuisChiaraandManuelMartin-LomasInstitutodeChimicaOrganica,C.S.I.C.J
2、uandelaCierva,3,E-28006MadridDedicatedtoProf.Dr.AnronioG6mez-Sbnchezontheoccasionofhis65thbirthday.(5.1X.91)Diazotransferfromtrifluoromethanesulfonylazide(TfN,)to2-amino-2-deoxy-glycosesconstitutesahigh-yielding,simpleprocedureforthepreparationofpartiallyprotectedorunprotected2-azido-2-deoxy
3、-aldoses.Thus,theo-allosaminederivative2gave93%of3,whilediazotransfertoo-glucosamine,o-mannosamine,ando-galactosamine,followedbyacetylation,yieldedtheazides5,7,and9inyieldsof74-91,65,and70%,respectively.Introduction.-The2-Azido-2-deoxyderivativesofmono-anddisaccharidesarefrequentlyusedinterm
4、ediatesinthesynthesisofamino-deoxyoligosaccharides(see[11forleadingref.).Theseazideshavebeenpreparedbyazidonitrationofglycals[2],byadditionofhalogenoazidestoglycals[3],andfrom1,6-anhydroglycoseseitherbyopeningofepoxides[4]orbysubstitutionof2-0-triflates[5].Thediastereoselectivityoftheazidoni
5、trationandhalogeno-azideadditiondependsontheconfigurationoftheglycal.Itishighforthelyxo-glycals,leadingtomixturesof2-azido-2-deoxy-galactosenitrates[2],andlowerforthearabino-glycals,leadingtomixturesof2-azido-2-deoxy-glucoseand-mannosederivatives[6].Thepreparationof2-azido-2-deoxy-glycalsfro
6、m1,6-anhydrosugarsproceedsinaconfigurationallycontrolledway,butrequiresarelativelylargenumberofsteps.The6-Azido-6-deoxyhexoseshavealsobeenpreparedfromthecorrespondingacetamidesbyN-nitrosation,reduction,andN-acylationtoN,N-diacylhydrazines,andagainN-nitrosation[7];thismethodhasbeenmodified[8]
7、forthetransformationof1,3,4,6-tetra-O-acetyl-2-N-benzyl-2-deoxy-~-~-glucopyranose(preparedfromglucos-amine)intothecorrespondingazideP-D-~[3](cf.Scheme)in49-55%overallyield.Finally,thesynthesisof~-az~do-~,~-d~deoxy-~-g~ycero-~-ga~acto-nonuloson~caci
