Ruthenium Hydride-Catalyzed Addition of Aldehydes to Dienes Leading to β,γ-Unsaturated Ketones

An efficient cross-addition reaction of dienes with aldehydes was developped by using RuHCI(CO)(PPh3)(3) as a catalyst to give a wide variety of beta,gamma-unsaturated ketones, where a pi-allylruthenium species, derived from hydroruthenation of diene, may be involved as a key intermediate.