Remarkable O₂-Effect in 1,4-Additions of Diethylzinc to 6-Acyloxy-2<i>H</i>-pyran-3(6<i>H</i>)-ones and 6-Alkoxy-2<i>H</i>-pyran-3(6<i>H</i>)-ones

Abstract

Under the influence of air, a facile 1,4-addition of diethylzinc to acyloxypyranones and alkoxypyranones 1 takes place. Reaction of diethylzinc with molecular oxygen provides EtOOZnEt, which catalyzes the addition of diethylzinc.