Regioselective benzoylation of sugars mediated by excessive Bu2SnO: observation of temperature promoted migration

Regioselective benzoylation of carbohydrates using an excess of dibutyltin oxide (Bu2SnO) at increased reaction temperatures has been developed for the synthesis of several glycoside benzoates with one or two free hydroxyl groups, including galactosides, glucosides, mannosides and lactosides in high yields. These compounds are useful as building blocks for the synthesis of complex saccharides and derivatives.