关键词: 5-乙基中氮茚, 4-甲基吡咯并[2, 1, 5-cd]中氮茚, 分子内缩合

Abstract: Pyrrolo[2,1,5-cd]indolizine is the most interesting member of bicyclo[3.2.2]azine. Its derivatives have received considerable attention in the field of synthetic organic chemistry due to their novel structure and properties,increasing biological interest and because their partially saturated frameworks occur in natural products. Over recent years the [8+2] cycloaddition of indolizine with an electron-deficient acetylene has been frequently employed for this purpose. In this paper we reported the synthesis of 5-methyl-pyrrolo[2,1,5-cd]indolizines starting from α -ethyl pyridine,which was converted at first to 3-acyl-5-ethyl indolizines by 1,3-dipolar cycloaddition of the corresponding pyridinium ylide with electron-deficient olefines and then the indolizines were transformed to pyrrolo[2,1,5-cd] indolizines by intramolecular condensation between the 3-acyl and the 5-ethyl groups.

Key words: 5-Ethyl-indolizines, 4-Methyl-pyrrolo[2,1,5-cd]indolizines, Intramolecular condensation