An Efficient Electrophile-Initiated Homoconjugate Addition of Acetate to Cyclopropyl Ketones.

Cleavage of the fused cyclopropanones (I) and (VII) with acetic anhydride (II) in the presence of boron trifluoride etherate leads to the formation of the unsaturated diacetates (III) and (IV) or (VIII).