Ru-Catalyzed Asymmetric Hydrogenation of γ-Heteroatom Substituted β-Keto Esters

A series of enantiomerically pure gamma-heteroatom substituted beta-hydroxy esters were synthesized with high enantioselectivities (up to 99.1% ee) by hydrogenation of gamma-heteroatom substituted beta-keto esters in the presence of Ru(S)-SunPhos catalyst. These asymmetric hydrogenations provide key building blocks for a variety of naturally occurring and biologically active compounds.