Richard W. Barnhart, David A. McMorran and B. Bosnich
The catalyst, [Rh(S,S-Me-duphos)(acetone)2]+, rapidly and efficiently converts 4-substituted pent-4-enals bearing primary and secondary substituents to the corresponding cyclopentanones and for a variety of substituents the ee was found to range from 93 to 96% at 25 °C.