Dynamic Kinetic Resolution of α,β‐Unsaturated Lactones through Asymmetric Copper‐Catalyzed Conjugate Reduction: Application to the Total Synthesis of Eupomatilone‐3

Only six steps were needed for the total synthesis of eupomatilone-3 in 48 % overall yield thanks to the development of a dynamic kinetic resolution that allowed the reductive conversion of a racemic α,β-unsaturated butenolide in high yield and high enantiomeric and diastereomeric excess. This copper-catalyzed dynamic kinetic resolution was then applied to several γ-aryl-containing α,β-unsaturated butenolides.