SYNTHESIS OF OCTAHYDROINDOLO 2, 3-a QUINOLIZINE DERIVATIVES

For the purpose of simplifying the skeletone structure of vincamine and searching for new drugs for cerebrovascular diseases, seventeen 1, 2, 3, 4, 6, 7, 12, 12b-octahydroindolo -2, 3-a quinolizine derivatives (Ⅱ～ⅩⅣ, ⅩⅦ, ⅩⅧ, ⅩⅪ, ⅩⅫ) and three compounds (ⅩⅨ, ⅩⅩ, ⅩⅩⅢ) with additional ring E′ were stereoselectively synthesized from enamine Ia, Ib and Ic. Three by-products (Ⅱ, ⅩⅨ and ⅩⅩ) and an unexpected compound ⅩⅩⅢ were isolated from the mother liquors and their structures were elucidated on the basis of IR, MS and 1HNMR spectra. The mechanisms of unexpected reactions for Ⅱ, ⅩⅨ and ⅩⅩ were suggested. In preliminary screening for the tolerance of mice to hypoxia, eleven compounds (Ⅱ-Ⅴ, Ⅶ-Ⅸ, ⅩⅦ, ⅪⅩ, ⅩⅪ, ⅩⅩⅢ) exhibited significant biological activity. Cerebral hemodynamic tests of these compounds are in progress.