Palladium(II)‐Induced Conversion of α‐Acetoxyalkynes into α,β‐Unsaturated α‐Acetoxyketones; a Novel Access to α‐Diketones

The α-acetoxyalkynes 1 react with [PdCl2(CH3CN)2] to form palladium complexes, which, on addition of one equivalent of water, give the α,β-unsaturated α-acetoxyketones 2. The transformation of α-acetoxyalkynes to α,β-acetoxyenones occurs with catalytic amounts of [PdCl2(CH3CN)2]. Alkaline hydrolysis of 2 readily affords the α-diketones 3.