O-Linked N-acetyl-d-glucosamine (O-GlcNAc) is a ubiquitous and essential modi- cation often found in proteins as being β-linked to serine or threonine amino acids. This important monosaccharide unit is also a component of carbohydrate polymers of bacterial cell walls, chitin, hyaluronic acids, and various other glycans. Moreover, O-GlcNAc is involved in a dynamic interplay with O-phosphate in a mechanism that controls protein function. Thus, the stereoselective synthesis of α-and β-O-linked GlcNAc probes for biological exploration in high yields and stereocontrol is important.
