Synthesis of hepta- and penta-saccharides, part of the complex-type carbohydrate portion of glycoproteins

Abstract

Silver trifluoromethanesulphonate-promoted condensation of 3,6-di-O-acetyl-4-O-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl)-2-deoxy-2-phthalimido-β-D-mannopyranoside and benzyl 2,4-di-O-benzyl-3,6-di-O-(3,4,6,-tri-O-benzyl-α-D-mannopyranosyl)-α-D-mannopyranoside gave a protected pentasaccharide and a protected heptasaccharide in 56% and 43% yield, respectively; after deblocking the free penta- and heptasaccharides were obtained.