Synthesis of glycosaminoglycan oligosaccharides. Part 4: Synthesis of aza-l-iduronic acid-containing analogs of heparan sulfate oligosaccharides as heparanase inhibitors

The synthesis of three azasugar-containing analogs of the disaccharide units of heparan sulfate, which are potential inhibitors of the enzyme heparanase, is reported. Synthetic routes were developed for the preparation of l-ido-nojirimycin type glycosyl acceptors with O-4 free. Glycosylation of these acceptors with an O-6 functionalized 2-azido-2-deoxy-d-glucose thioglycoside donor afforded the α-linked disaccharides in good yields. The advantages of using the 4-nitrobenzenesulfonyl group for the protection of the ring nitrogen of azasugars were demonstrated.