摘要:
Lithiation with butyllithium of N-(alpha-ethoxyallyl)benzotriazole (2) (readily prepared in quantitative yield on a large scale from benzotriazole and acrolein diethyl acetal (9)) followed by reaction of lithio derivative 14 with halides, alpha,beta-unsaturated esters, alpha,beta-unsaturated ketones, and aldehydes gave exclusively alpha-alkylation adducts. These adducts are hydrolyzed under extremely mild conditions, enabling convenient syntheses of vinyl ketones 16 and functionalized vinyl ketones 21, 22, 24, and 27.