Azidation of 1,2-anhydro sugars with NaN(3) in CH(3)CN by using a catalytic amount of ceric ammonium nitrate has been accomplished in a regio- and stereoselective manner. Various 1,2-anhydro sugars produced 2-hydroxy-1-azido sugars in good yields which, in turn, were converted to structurally diverse sugar-derived morpholine triazoles and sugar oxazin-2-ones. These sugar derivatives were tested against various commercially available glycosidases, and two of them were found to be active in the micromolar range.

A new reagent system comprising acetyl chloride, silver nitrate, and acetonitrile has been developed for the synthesis of 2-nitroglycals from the corresponding glycals. Under certain conditions, the formation of 2-nitro-1-acetamido sugars has also been observed. In addition, a few other non-carbohydrate-derived olefins also gave the corrresponding conjugated nitroolefins.

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SummaryA carbon-Ferrier rearrangement on glycals has been performed by using ceric ammonium nitrate to obtain products in moderate to good yields with high selectivity. The versatility of this method has been demonstrated by applying it to differently protected glycals and by employing several nucleophiles. The obtained C-allyl glycoside has been utilized for the synthesis of a orthogonally protected 2-amino-2-deoxy-C-glycoside.

Synthesis of isofagomine has been achieved by implementation of aza-Claisen rearrangement of 2-C-hydroxymethyl glycals as a key step. The above rearrangement has also been utilized in the synthesis of biologically important polyhydroxylated piperidine frameworks such as isogalactofagomine, ent-isogalactofagomine and their analogues and some other azasugars as glycosidase inhibitors.