Abstract: Aromatic and aliphatic aldehydes were transformed to1,1-diacetates (acylals) under mild conditions by treatment with acetic anhydride and Cu3/2PMo12O40/SiO2 catalyst. This catalyst was efficient for the preparation of1,1-diacetate under solvent-free conditions. The reverse reaction using the resulting1,1-diacetate was achieved using the same catalyst in acetonitrile as a solvent. This new method has the advantages of excellent yields and short reaction time. The catalyst can be reused several times although it gets less active.

Key words: heteropoly acid, polyoxometalate, aldehyde, 1-diacetate, supported catalyst