4-HYDROXYCOUMARINS AS MICHAEL DONORS IN ASYMMETRIC ROUTES TO POLYCYCLIC COUMARINS (MICROREVIEW)

Abstract

Different [3,4]-fused polycyclic 2H-chromen-2-ones can be prepared in a stereoselective fashion starting from 4-hydroxycoumarins as nucleophilic synthones. Herein we report a brief overview of the most recent methods including Pd-catalyzed [3+3] annulation processes, organocatalytic one-pot and domino Michael addition/cyclization, tandem conjugate addition/hydroxyalkylation, and organocascade catalytic reaction.