THE CARBOHYDRATE–PROTEIN LINKAGE IN GLYCOPROTEINS: PART II. THE SYNTHESIS OF N-L-SERYL-D-GLUCOSAMINE AND N-L-THREONYL-D-GLUCOSAMINE

Abstract

N-L-Seryl-D-glucosamine has been prepared by the condensation of N-carbobenzoxy-L-serine with D-glucosamine in the presence of dicyclohexyl carbodiimide followed by hydrogenolysis of the resulting N-(N-carbobenzoxy-L-seryl)-D-glucosamine to remove the N-carbobenzoxy protecting group.N-L-Threonyl-D-glucosamine has been prepared by (a) the condensation of 1,3,4,6-tetra-O-acetyl-α- (and β-) D-glucosamine and N-carbobenzoxy-O-tetrahydropyranyl-L-threonine in the presence of diisopropyl carbodiimide followed by the removal of the protecting groups from the resulting N-(N-carbobenzoxy-O-tetrahydropyranyl-L-threonyl)-1,3,4,6-tetra-O-acetyl-α- (and β-) D-glucosamine, and (b) by the condensation of N-carbobenzoxy-L-threonine with D-glucosamine in the presence of dicyclohexyl carbodiimide followed by removal of the N-carbobenzoxy group from the resulting N-(N-carbobenzoxy-L-threonyl-D-glucosamine by hydrogenolysis.