Efficient synthesis of lactosaminylated core-2 O-glycans

A series of lactosaminylated oligosaccharides found in mucin type O-glycans was synthesized using a generalized block strategy. The synthesis involved the addition of a protected lactosamine donor to a partially protected T-disaccharide derivative. The nonreducing galactose residues of the deblocked oligosaccharide products could be removed by beta-galactosidase from jack bean to produce the corresponding GlcNAc terminated compounds. A series of tri- to hexasaccharides was thus efficiently produced.