Acid-catalysed thermal rearrangement of γ,δ-unsaturated ketones

Abstract
Thermal activation of γ,δ-unsaturated ketones (1, 9 and 12) in the presence of a catalytic amount of propionic acid causes a rearrangement to give new γ,δ-unsaturated ketones (2, 10 and 14)via an intramolecular ene reaction followed by a retro-ene reaction.