BENZOTRIAZOLE-STABILIZED AND 1,2,4-TRIAZOLE-STABILIZED ALLYLIC ANIONS- APPLICATIONS IN SYNTHESES OF FUNCTIONALIZED ALPHA,BETA-UNSATURATED KETONES, GAMMA-LACTONES, GAMMA-LACTAMS, AND BETA-SUBSTITUTED ESTERS

Deprotonated 1-(benzotriazol-1-yl)-1-ethoxy-2-hexene (7) reacted with alkyl halides, aldehydes, ketones, imines, and alpha-beta-unsaturated esters to give exclusively the alpha-alkylated products 8a-c, 10a,b, 1 2, 14, 16, and 18a,b, respectively. Without isolation, these products were hydrolyzed under mild conditions to generate the corresponding si mple or functionalized alpha,beta-unsaturated ketones 9a-c, 11a,b, 13, 15, 17, and 19a,b. Similar reactions with the phenyl-substituted anal og 3-(benzotriazol-1-yl)-3-ethoxy-1-phenyl-1-propene (21) also gave th e analogous alpha-products, but they were accompanied by small amount of the gamma-products in most cases. By contrast, deprotonation of the corresponding triazole derivative 29 with butyllithium followed by re actions with alkyl halides, aldehydes, ketones, or imines yielded excl usively gamma-alkylated adducts 32, 34, 36, 38, 40, and 42. Intermedia tes 32, 34, 36, 38, 40, and 42 were readily converted into beta-substi tuted esters 33a-c, gamma-lactones 35a,b, 39, 41, and 43, and gamma-la ctams 37a-c on hydrolysis.