Reactions of 3-carene, limonene, and α-pinene nitrosochlorides with imidazole, benzotriazole, and indole

Abstract

The reactions of terpene nitrosochlorides derived from 3-carene, α-pinene, and limonene, with simplest azaheterocycles (imidazole, benzotriazole, and indole) were studied. On the base of these transformations, preparative procedures to access chiral oximes bearing azaheterocyclic moieties in the α-position to the oxime fragment, namely, α-(1H-imidazol-1-yl)-, α-(1H-benzo-[d][1,2,3]triazol-1-yl)-, and α-(1H-indol-3-yl)-substituted terpenic oximes, were developed. Transformations of the studied monoterpene nitrosochlorides into α-substituted oximes proceeded stereoselectively to give in the moderate yields (30–60%) the only stereoisomer arising from the attack of the heterocyclic anion from the less hindered side of the intermediate nitroso olefin generated in situ from nitrosochloride.