Enantioselective Construction of Spirocyclic Oxindole Derivatives with Multiple Stereocenters via an Organocatalytic Michael/Aldol/Hemiacetalization Cascade Reaction

An efficient organocatalytic Michael/aldol/hemiacetalization cascade reaction for construction of enantioenriched spirocyclic oxindoles fused with tetrahydropyrane has been developed. The desired highly functionalized 5',6'-dihydro-2'H,4'H-spiro [indoline-3,3'-pyran]-2-one derivatives containing multiple stereogenic centers were obtained in moderate to high chemical yields and with high stereo-selectivities.