Ethylidene diacetate is an organic compound with the formula (CH3CO2)2CHCH3. A colorless low-melting solid, it once served as a precursor to vinyl acetate. Preparation A major industrial route involves the reaction of acetaldehyde and acetic anhydride in the presence of a ferric chloride catalyst: CH3CHO + (CH3CO)2O → (CH3CO2)2CHCH3 It can be converted to the valuable monomer vinyl acetate by thermal elimination of acetic acid: (CH3CO2)2CHCH3 → CH3CO2CH=CH2 + CH3CO2H References Acetate esters