Total synthesis of 4d-deoxy Lewisx pentasaccharide

Abstract Total synthesis of 4d-deoxy Lewis x pentasaccharide is described. O -(2,3,6-Tri- O -benzoyl-4-deoxy-α- d -xylo-hexopyranosyl)trichloroacetimidate was condensed with a diol of glucosamine to give regioselectively a β1 → 4 linked disaccharide, which was further fucosylated to a protected deoxy Lewis x trisaccharide. A highly stereo- and regioselective glycosylation of this trisaccharide onto a lactoside diol was performed to provide a pentasaccharide in excellent yield. After deprotection, this pentasaccharide afforded the target oligosaccharide.