Chemoselective Synthesis of Substituted Benzocchromen-6-ones through Base-Promoted Reaction of alpha,beta-Unsaturated Coumarins and alpha-Cyano Carbonyls

摘要

A general and efficient method for the chemoselective synthesis of benzo[c]chromen-6-ones has been developed. This involved a base-promoted nucleophilic substitution/deprotonation/intramolecular aldol condensation/carboxylic acid or alkyl hydrogen carbonate elimination/aromatization reaction of alpha-cyano carbonyls and alpha,beta-unsaturated coumarins. Readily available starting materials, green and mild conditions, synthetically useful yields, and operational simplicity are some highlighted advantages of this transformation.