Phenol-mediated decarboxylative proton transfer of γ-methylidene-δ-valerolactones: an approach towards (E)-2,4-pentadienoates

Abstract

A phenol-mediated decarboxylative proton transfer of γ-methylidene-δ-valerolactones (GMDVs) was developed, affording the target polysubstituted (E)-2,4-pentadienoates in 99% yields with E/Z up to 99 : 1. In this reaction, 4-NO₂C₆H₄OH as a dual ligand and proton shuttle is used to tame the living Pd(II) 1,4-zwitterionic complexes in the decarboxylative proton transfer of γ-methylidene-δ-valerolactones (GMDVs).