Methanolysis of acetylated sugars and glycosides in the presence of tin oxides and alkoxides

A simple, regioselective O-deacetylation procedure is described which involves ≤0.5 equiv. of Bu₃SnOMe or Bu₂SnO in methanol. Anomeric acetates are considerably more reactive than primary and secondary acetates, thereby enabling selective removal, to give ∼70% of products with HO-1 unsubstituted. Prolonged reaction resulted in complete deacetylation. Secondary acetates were removed faster than primary acetates and the overall rates of reaction were influenced greatly by the anomeric substituent in the order of OAc {A figure is presented} OH ≫ OMe. No acyl migration took place under the reaction conditions.