Asymmetric Synthesis of γ‐Lactones Bearing α,γ‐Bis‐quaternary Stereocenters via Chiral Bifunctional Sulfide‐Catalyzed Desymmetrizing Bromolactonization

The structure of highly substituted chiral γ‐lactones is found in many important natural products. Therefore, the development of methods for the catalytic asymmetric synthesis of highly substituted γ‐lactones is recognized as an important area of research. Catalytic asymmetric halolactonizations are known to be reliable methods for the stereoselective preparation of optically active γ‐lactones. However, catalytic asymmetric halolactonizations for the synthesis of highly substituted γ‐lactones, such as α,γ‐bis‐quaternary γ‐lactones with four different carbon substituents on the lactone backbone, remain underdeveloped. To address this limitation, we report here the diastereo‐ and enantioselective synthesis of α,γ‐bis‐quaternary γ‐lactones possessing four carbon substituents at the α‐ and γ‐positions, achieved through chiral bifunctional sulfide‐catalyzed desymmetrizing bromolactonization.