Synthesis of Laminin Hexasaccharide Analogue

Abstract

The synthesis of laminin hexasaccharide analogue di-O-[Gal-β-(1→4)-Glc-β]-(1→2)-(1→6)-man-α-(1→6)-man-α-Me derivative (1) was achieved with 1,2-anhydromannopyranose benzyl ether (3) as the key intermediate. Coupling of 3 with methyl 2,3,4-tri-O-benzyl-α-D-mannopyranoside (4) promoted by ZnCl₂ gave methyl 2,3,4-tri-O-benzyl-6-O-(3,4,6-tri-O-benzyl-α-D-mannopyranosyl)-α-D-mannopyranoside (2a). Selective 6-O-debenzylation of 2b with ZnCl₂-Ac₂O-HOAc followed by coupling with acetobromolactopyranose afforded 1.