First synthesis of 3′-deoxy Lewisx pentasaccharide

The total synthesis of 3′-deoxy Lewis x pentasaccharide is reported. 4- O -Acetyl-2,6-di- O -benzoyl-3-deoxy-β- d -xylo-hexopyranosyl trichloroacetimidate was condensed with a diol of glucosamine to give a disaccharide, which was further fucosylated to a Lewis x trisaccharide analogue. Glycosylation of a lactoside diol with this trisaccharide provided a pentasaccharide, which after deprotection, afforded the target pentasaccharide.