Synthesis of Acylals from Aromatic Aldehydes and Their Deprotections Catalyzed by Synthetic Phosphates: Practical and Ecological Approach

An efficient and clean preparation of acylals from aromatic aldehydes in the presence of synthetic phosphates (flourapatite and hydroxyapatite doped with ZnCl2 and ZnBr2) and acetic anhydride was achieved easily in high yields (86% - 97%) at room temperature under solvent-free conditions. Deprotec- tion of the resulting acylals has also been attained by using the same catalysts under microwave irradiation. This method consistently has advantage of ex- cellent yields (82% - 96%) and a short reaction time (3 - 4 min).