Lithiation with butyllithium of N-(a-ethoxyally1) 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, a,/?-unsaturated esters, a,/?- unsaturated ketones, and aldehydes gave exclusively a-alkylation adducts. These adducts are hydrolyzed under extremely mild conditions, enabling convenient syntheses of vinyl ...