Synthesis of Flavones and γ‐Benzopyranones Using Mild Sonogashira Coupling and 18‐Crown‐6 Ether Mediated 6‐<i>endo</i> Cyclization

Abstract

Abstract An efficient method for the synthesis of flavones and γ‐benzopyranones has been developed utilizing a mild Sonogashira coupling and 18‐crown‐6 ether mediated 6‐ endo cyclization of o ‐alkynoylphenyl acetates. By using this strategy, flavones and γ‐benzopyranones bearing electron‐donating groups, halogens, and simple alkyl substituents were synthesized in satisfactory yields.