Palladium‐Catalyzed Alkynylative Lactonization of Unsaturated Bicyclic Carboxylic Acids: Synthesis of Fused Polycyclic γ‐Lactone Compounds

Abstract

AbstractUnsaturated bicyclic carboxylic acids undergo palladium‐catalyzed coupling with bromoalkynes to produce γ‐alkynyl lactones in moderate to good yields with excellent chemo‐ and regioselectivity. The reaction conditions were extremely mild, and functional groups such as methyl, methoxy, chloro, and bromo were tolerated under the optimized reaction conditions. Moreover, γ‐chloroalkenyl lactones were facilely synthesized through chloropalladation/carboesterification of electron‐deficient C≡C bonds by using molecular oxygen as the sole oxidant.