Design and enantioselective synthesis of Cashmeran odorants by using "enol catalysis".

Novel Cashmeran odorants were designed by molecular modeling. Their short syntheses involve a novel asymmetric Brønsted acid catalyzed Michael addition of unactivated α-substituted ketones. This key transformation was realized by utilizing a new type of enol activation catalysis and affords different cyclic ketones bearing α-quaternary stereocenters in good to excellent yields and with high enantioselectivity.