Diastereoselective Synthesis of γ-Lactones through Reaction of Enediolates with α,β-Unsaturated Sulfoxonium Salts

Studies of the reaction of lithium enediolates with α,β-unsaturated sulfoxonium salts are described. γ-Lactones were formed in very good to excellent yields (82% → 99% for 11 examples) and with very good to excellent diastereoselectivity (dr >90:10 for 10 examples), favoring the trans-diastereomer.