Synthesis of N ‐Glycopeptide Clusters with Lewis x Antigen Side Chains and Their Coupling to Carrier Proteins

As a tumor‐associated cell‐antigen mimic , Lewis x trisaccharide determinant 1 was constructed with the azide function as anomeric protecting group with the aid of a 4‐Mpm‐protected (Mpm = methoxyphenylmethyl) fucosyl donor. Exchange of the OMpm functions for OAc groups furnishes a Lewis x trisaccharide stable enough against acid attack for glycopeptide synthesis. A glycopeptide with two Lewis x antigen side chains was deblocked and coupled to bovine serum albumin as well as to KLH (keyhole limpet hemocyanin). These synthetic glycoproteins simulate biantennary Lewis x antigen structures.