Diastereo- and enantioselective construction of cyclohexanone-fused spirospyrazolones containing four consecutive stereocenters through asymmetric sequential reactions

Abstract

The diastereo- and enantioselective synthesis of cyclohexanone-fused spirospyrazolones through an asymmetric Michael/Michael/aldol cascade reaction catalyzed by squaramide and diphenylprolinol silyl ether, followed by a sequential oxidation was developed.