2-nitro thioglycoside donors: versatile precursors of beta-D-glycosides of aminosugars.

2-Nitro thioglycosides can be prepared by the Michael addition of thiophenol to 2-nitroglycal derivatives. NIS/TMSOTf activation of these 2-nitro thioglycosides, in the presence of alcohols, rapidly and cleanly led to the desired glycosides in good yield and beta-selectivity. Reduction of the nitro group allowed generation of the corresponding 2-acetamido glycosides.