Synthesis of the Key Disaccharide of 3′-Sulfo Lewis X and Lewis A: The Novel E-Selectin Ligand

Abstract

Benzyl 2,4,6-tri-O-benzyl-β-D-galactopyranoside (6) was synthesised from regioselective protection of stannylated benzyl 2,6-di-O-benzyl -β-D-galactopyranoside (3) with 4-methoxybenzyl chloride, followed by benzylation and oxidative removal of the temporary protecting group. The disaccharide (2) was prepared by condensation of the common acceptor 6 with 7 through thial activation as well as with 8 following Konigs Knorr procedure.