Cu(II)-Catalyzed Acylation by Thiol Esters Under Neutral Conditions: Tandem Acylation-Wittig Reaction Leading to a One-Pot Synthesis of Butenolides

The first catalytic acylation of alcohols with a thiol ester present in Wittig reagents under neutral conditions catalyzed by the Cu(II) salt through a push−pull mechanism is reported. Furthermore, a new methodology for the one-pot lactonization of acyloins by a copper catalyst is developed. The synthetic utility of this method for the synthesis of natural products is shown.