Synthesis of the 6-deoxytalose-containing tetrasaccharide of the glycopeptidolipid from Mycobacterium intracellare serotype 7
作者:Shiqiang Yan、Xiaomei Liang、Peiyu Diao、Ye. Yang、Jianjun Zhang、Daoquan Wang、Fanzuo Kong
DOI:10.1016/j.carres.2008.09.010
日期:2008.12
An efficient synthesis of 4-methoxyphenyl alpha-L-Rhap-(1 -> 3)-alpha-L-Rhap-(1 -> 3)-alpha-L-Rhap-(1 -> 2)-6-deoxy-alpha-L-Talp, the tetrasaccharide related to the GPLs of Mycobacterium intracellare serotype 7, was achieved with 4-methoxyphenyl 3,4-di-O-benzoyl-6-deoxy-alpha-L-talopyranoside (6c) as the key intermediate which was obtained through selective 3-O-benzoylation of 4-O-benzoyl-6-deoxy-alpha-L-taloside. Coupling of 6c with 3-O-allyloxycarbonyl-2,4-di-O-benzoyl-alpha-L-rhamnopyranosyl trichloroacetimidate followed by removal of the allyloxycarbonyl protecting group afforded the disaccharide acceptor 11. Condensation of 11 with 2,3,4-tri-O-benzoyl-alpha-L-rhamnopyranosyl-(1 -> 3)-2,4-di-O-benzoyl-alpha-L-rhamnopyranosyl trichloroacetimidate and subsequent deprotection gave the target tetrasaccharide. (C) 2008 Elsevier Ltd. All rights reserved.