SYNTHETIC GLYCOCONJUGATES .3. AN EFFICIENT SYNTHESIS OF A GLYCOPROTEIN MODEL HAVING A LE(X)-TYPE TRISACCHARIDE SEQUENCE OF TUMOR-ASSOCIATED CARBOHYDRATE ANTIGEN

A unique and efficient synthetic strategy for the macromolecule containing the tumor-associated antigenic oligosaccharide, Lewis x (Le(x)), is described. A novel standardized intermediate derived from an available 1,6-anhydro-beta-lactose remarkably facilitated the conventional synthetic route of a peracetate of Galp beta(1 --> 4) [Fucp alpha(1 --> 3)]GlcpNAc as an important precursor for the preparation of the targeted polymerizable glycoside. Introduction of an n-pentenyl group at the anomeric position into the peracetate of Le(x) through a reactive oxazoline derivative successfully afforded a new type of carbohydrate monomer. Copolymerization of the glycoside with acrylamide proceeded smoothly and gave a biochemically interesting glycoprotein model having a pendant Le(x) structure.