Synthesis of novel donor mimetics of UDP-Gal, UDP-GlcNAc, and UDP-GalNAc as potential transferase inhibitors

For the enzymatic transfer of galactose, N-acetylglucosamine, and N-acetylg alactosamine, UDP-Gal (1), UDP-GlcNAc (2), and UDP-GalNAc (3) are employed, and UDP serves as a feedback inhibitor. In this paper the synthesis of the novel UDP-sugar analogues 4, 5, and 6 as potential transferase inhibitors is described. Compounds 4-6 feature C-glycosidic hydroxymethylene linkages between the sugar and nucleoside moieties in contrast to the anomeric oxyge ns in the natural derivatives 1-3.