Catalytic Enantioselective Diels–Alder Reaction of Dienes with Acyclic and α,β- and β,β-Disubstituted Enones

Despite the wealth of methods to enantioselectively catalyze Diels–Alder reactions of α,β-unsaturated carbonyl dienophiles, until today, not a single example with an acyclic enone that is either β,β- or α,β-disubstituted has been reported. Herein, we disclose a general Brønsted acid-catalyzed enantioselective Diels–Alder reaction of various aliphatic acyclic disubstituted enones with hydrocarbon dienes featuring diverse steric and electronic properties. The established method has been employed to synthesize several enantiopure targets, including well-known fragrance components such as arborone and the damascones.