Rapid and Effective Synthesis of α-Acyloxy-α-alkynyltrimethylsilanes

α-Alkynyl-α′-trimethylsilylhydrazones are readily oxidized into diazo compounds under simple experimental conditions. These stable diazo species can in turn react with a range of carboxylic acids via a protonation–nucleophilic substitution sequence, leading to valuable α-acyloxy-α-alkynyltrimethylsilanes. This procedure avoids the delicate preparation and manipulation of α-hydroxypropargyltrimethylsilanes.