A new method of oligosaccharide synthesis: Rhamnobioses

✍ Scribed by Alina Jaworska; Aleksander Zamojski

• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 844 KB
• Volume: 126
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(84)85377-x

✦ Synopsis

A semi-synthetic approach to (1+2)-(r-and (l-3)-a-linked rhamnobioses is presented. The method involves condensation of benzyl2-O-or 3-0-benzoyl-4-0benzyl-a-L-rhamnopyranoside (5) with l-O-acetyl-2,3,6-trideoxy-a,P-DL-glycerohex-2-enopyranos-4-ulose (6)) isolation of the L-L and D-L forms of the resulting disaccharide derivatives, reduction of the carbonyl groups to give a-erythro unsaturated products, and cis-hydroxylation to form the rhamnobiose derivatives. Removal of the protecting groups then gave a-L-Rhap-(1+2)+Rhap, cu-L-Rhap-(1+3)+Rhap, and the corresponding D-L stereoisomers. The 'H-and 13C-n.m.r. data are of diagnostic value in differentiating the stereoisomers. 1-(2-Furyl)ethanol was resolved into its enantiomers, and the (+)-form was converted into (+)-6 which in turn was condensed with 5. The structure of the products indicated that (+)-1-(2-furyl)ethanol has the R configuration.