Efficient synthesis of tetrahydronaphthalene- or isochroman-fused spirooxindoles using tandem reactions

The flexible and simple cascade reaction involving a Michael-aldol or vinylogous Henry-acetalization relay is described. We have used the cascade reaction to assemble functionalized tetrahydronaphthalene- or isochroman-fused spirooxindoles and other drug-like spirocyclic scaffolds. The mild reaction conditions, short reaction times, and high tolerance for various functional groups make this method attractive for constructing pharmacologically interesting architectures.