Asymmetric Synthesis of Tri- and Tetrasubstituted Trifluoromethyl Dihydropyranones from α-Aroyloxyaldehydes via NHC Redox Catalysis

Abstract

The asymmetric synthesis of tri- and tetrasubstituted trifluoromethyl dihydropyranones via an NHC-catalyzed redox process, introducing methyl, benzyl, and aryl substituents to the C(5) position, is presented. Their substrate-controlled derivatization into δ-lactones and cyclic hemiacetals containing stereogenic trifluoromethyl groups is also described.