Synthesis of tri- and pentasaccharide fragments corresponding to the O-antigen of Shigella boydii type 6

Abstract

A convenient synthetic strategy for the synthesis of the acidic pentasaccharide repeating unit and its trisaccharide fragment corresponding to the O-antigen of Shigella boydii type 6 has been successfully developed A stereoselective sequential glycosylation method has been exploited to obtain the target tri- and pentasaccharide derivatives Most of the synthetic intermediates were solid and prepared in high yields from commercially available reducing sugars following a series of protection-deprotection reactions A late-stage TEMPO mediated selective oxidation reaction finally resulted in the pentasaccharide containing a glucuronic acid unit A 2-(4-methoxyphenoxy) ethyl group has been chosen as the anomeric protecting group to provide trisaccharide and pentasaccharide derivatives linked to an ethylene glycol linker (C) 2010 Elsevier Ltd All rights reserved