Abstract An efficient method for the synthesis of 1, 1??diacetates (acylals) from different aldehydes in the presence of (NH4) 3PW12O40 and acetic anhydride under solvent??free conditions at ambient temperature is achieved. Selective conversion of aldehydes was observed in the presence of ketones. The deprotection of acylals has also been achieved using (NH4) 3PW12O40 in methanol. The catalyst was found to possess good activity and ...