Simple synthesis of β-damascenone and related compounds

Abstract

β-Damascenone (I; R = Me) is obtained in overall yields of 30–40% by a sequence involving aluminium chloride-catalysed Diels–Alder addition of penta-1,3-diene to 3-bromo-4-methylpent-3-en-2-one, followed by dehydrobromination, base-catalysed condensation with acetaldehyde, and elimination of water.