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.