Desymmetrization Process by Mg(II)-Catalyzed Intramolecular Vinylogous Michael Reaction

Chiral magnesium catalyzed intramolecular vinylogous Michael reaction of novel cyclohexadienones via a desymmetrization process is reported. (R)-BINOL derived ligand and an achiral amide were employed in the current in situ generated magnesium catalyst, giving the corresponding hydrogenated benzofuranone skeletons in good to excellent enantioselectivities with high yields. This simple and efficient strategy could be utilized for the synthesis of aromatized alpha,beta-unsaturated ester and Br-substituted hydrogenated benzofuranone in good yields under mild conditions.