Recent Developments of Protecting-group-free and Stereoselective Glycosylation

Abstract

Oligosaccharides, are linked to biomolecules (i.e. proteins and lipids) by glycosidic bonds, display on the surface of cells and play important roles in a wide range of biological events. Recent remarkable advances in carbohydrate chemistry can provide structurally well-defined oligosaccharides, which lead to molecular-level elucidation of their functions. In conventional approaches for oligosaccharide synthesis, to glycosylate at a given carbohydrate hydroxyl group, other hydroxyl groups must be masked with protecting groups. Recently, however, “protecting-group-free” synthetic approaches, are challenging and promising, have been reported by several research groups. This present review describes recent developments of stereoselective glycosylations using unprotected glycosyl donors.