Efficient synthesis of diacetal of pentaerythritol under microwave irradiation using heteropoly acid H3PW12O40

Tungstophosphoric acids (HPA) act as an efficient heterogeneous catalyst for the simple, and environmentally friendly synthesis of acetals in microwave at shorter reaction time with moderate microwave power superior to liquid phase involving HPA and various other heterogeneous catalysts, where the reactants were refluxed with benzene/toluene solvents for longer duration. While aryl aldehydes acetals are often easily prepared from their respective ketones, many acetals from aryl alkyl and diaryl ketones have been less accessible because of electronic and steric factor. This paper pays a greener alternative route for the direct transformation of such wide range of ketones and aldehydes into their respective acetals in short reaction time with high selectivity and yield, without the need for solvents in contrast to conventional method.