Toward the modular synthesis of glycosaminoglycans: synthesis of hyaluronic acid disaccharide building blocks using a periodic acid oxidation

The synthesis of two differentially protected GluNAc-β(1→4)-GluA and GluA-β(1→3)-GluNAc disaccharide modules for the solid-phase assembly of hyaluronic acid are described. A periodic acid/chromium trioxide oxidation was the key transformation to facilitate access to the glucuronic acid moiety from glucose and should find wide application in the oxidation of primary alcohols.