Metal Salt-Catalyzed Addition of Lithium Enolates of Ketones to 1,2-Epoxides. An Efficient Route to α-Alkyl-γ-Hydroxy Ketones

Sc(OTf)3 (10% mol) is a particularly effective catalyst in promoting the addn. reaction of lithium enolates of ketones to 1,2-epoxides to afford in good yield γ-hydroxy ketones. The diastereoselectivity of the catalyzed addn. reactions of enolate (Z)-LiOCPh:CHMe, derived from propiophenone, and the enolate derived from α-tetralone to propene oxide and cyclohexene oxide turned out to be poor, showing only a weak preference for the syn adduct.