Asymmetric Synthesis of Spirooxindole δ-Lactones with Vicinal Tertiary and Quaternary Stereocenters via Regio-, Diastereo-, and Enantioselective Organocatalytic Vinylogous Aldol-cyclization Cascade Reaction

A highly region-, diastereo-, and enantioselective organocatalytic vinylogous aldol-cyclization cascade reaction of prochiral 3-akylidene oxindoles to isatins has been achieved by using bifuctional organocatalysts. A variety of enantioenriched spirooxindole -lactones with vicinal tertiary and quaternary stereocenters were generated in good to excellent yields with good to high diastereoselectivities and enantioselectivities.