A synthesis of α-lithiated enol ethers from α-arenesulfinyl enol ethers:: Ni(0)- and Pd(0)-catalysed coupling of enol triflates and phosphates derived from lactones with sodium arenethiolates gives α-arenesulfanyl enol ethers

A three-step synthesis of stable and storable alpha-benzenesulfinyl enol ethers from lactones entails (a) conversion of a lactone to an enol triflate or phosphate; (b) Ni(0) and Pd(0) cross-coupling of the enol triflate or phosphate with a sodium arenethiolate to give an alpha-arenethio enol ether; and (c) oxidation of an arenethio group to a sulfoxide. The alpha-benzenesulfinyl enol ethers undergo sulfoxide-lithium exchange on reaction with n-BuLi to give alpha-lithiated enol ethers thus making the alpha-benzenesulfinyl group a surrogate for the trialkylstannyl group which has hitherto served as the most common precursor to alpha-lithiated enol ethers.