Synthesis of 3-azido-3-deoxy-β-d
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- 作者：Christopher T. Ö ; berg ; Ann-Louise Noresson ; Tamara Delaine ; Amaia Larumbe ; Johan Tejler ; Henrik von Wachenfeldt ; Ulf J. Nilsson
- 关键词：Galactose ; Gulose ; Epimerization ; Azide
- 刊名：Carbohydrate Research
- 出版年：2009
- 出版时间：27 July 2009
- 年：2009
- 卷：344
- 期：11
- 页码：1282-1284
- 全文大小：196 K
文摘
Three efficient routes to 3-azido-3-deoxy-β-d-galactopyranosides were developed relying on a double inversion protocol at C3. Two of the routes were demonstrated to work with both O- and S-glycosides. In all three routes, the 2-O-acetyl-3-azido-4,6-O-benzylidene-3-deoxy-β-d-galactopyranosides were obtained by an azide inversion of the key intermediates 2-O-acetyl-4,6-O-benzylidene-3-O-trifluoromethanesulfonyl-β-d-gulopyranosides. The intermediate gulopyranosides were in turn obtained from 2-O-acetyl-4,6-O-benzylidene-3-O-trifluoromethanesulfonyl-β-d-galactopyranosides, installed in one pot from the 4,6-O-benzylidene-β-d-galactopyranosides, by inversion with nitrite or acetate. For O-glycosides, the gulopyranoside configuration could alternatively be obtained from the 4,6-O-benzylidene-β-d-galactopyranoside by elimination to give the 2,3-dianhydro derivative followed by a highly stereoselective cis-dihydroxylation.