NOVEL AND CONVENIENT ROUTES TO FUNCTIONALIZED ALKYNYL KETONES FROM 1-(BENZOTRIAZOL-1-YL)PROPARGYL ETHYL ETHERS

1-(Benzotriazol-1-yl)propargyl ethyl ethers, readily accessible from p ropargyl aldehyde diethyl acetals and benzotriazole, undergo smooth Li thiation at the methine carbon and subsequent reactions with alkyl hal ides, aldehydes, ketones, imines, esters, trialkylsilyl chlorides, dia lkyl carbonates, and isocyanates to yield the corresponding substitute d ethers. Hydrolysis of these intermediates under acidic conditions af fords a wide variety of alkynyl ketones bearing hydroxy, amino, acyl, trimethylsilyl, alkoxycarbonyl, and (alkylamino)carbonyl substituents at the alpha-position in good to excellent overall yields.