Catalytic and Regioselective Oxidation of Carbohydrates To Synthesize Keto-Sugars under Mild Conditions

A new catalytic and regioselective approach for the synthesis of keto-sugars is described. An organotin catalyst, Oc(2)SnCl(2), in the presence of trimethylphenylammonium tribromide ([TMPhA]Br-+(3)-) accelerates the regioselective oxidation at the axial-OH group of 1,2-diol moieties in galactopyranosides. The reaction conditions can also be used for the regioselective oxidation of various carbohydrates.