Enantioselective Vinylogous Aldol/Lactonization Cascade Reaction between β,γ-Unsaturated Amides and α,β-Unsaturated Trifluoromethyl Ketones

An organocatalytic enantioselective vinylogous aldol/lactonization cascade reaction between β,γ-unsaturated amides and α,β-unsaturated trifluoromethyl ketones has been developed. With a (R,R)-cyclohexanediamine-based tertiary amine-thiourea catalyst, optically active trifluoromethyl dihydropyranones have been constructed in moderate to excellent yields (up to 99%) with excellent enantioselectivities (98 → 99.5% ee). Moreover, the transformations of chiral product 3aa, including the reduction of the C-C double bonds and the lactone, have been explored.