Synthesis of UDP-GalNAc analogues as probes for the study of polypeptide-α-GalNAc-transferases. Part 2

The synthesis of four UDP-GalNAc analogues (1–4) is described. The 3-, 4- and 6-deoxygenated analogues 1–3 were obtained by way of a divergent strategy starting from a 3,6-di-O-pivaloyl GlcNAc derivative as a common precursor. Analogue 4 bearing a N-trifluoroacetamido group was prepared from the trifluoromethylated oxazoline 24 as key intermediate. These compounds were designed to probe the substrate specificity of polypeptide-α-GalNAc transferases.