薯蓣皂甙元乙酸酯溴代反应及其溴代产物的选择性脱溴  

The bromine-addition of diosgenin-3β-acetate and the regioselective debromination of its brominated by-product 5,6,23-tribromodiosgenin-3β-acetate

作　　者：田博[1] 顾春燕[1] 金荣华[1] 林静容[1] 

机构地区：[1]上海师范大学生命与环境科学学院资源化学实验室,上海200234

出　　处：《上海师范大学学报（自然科学版）》2009年第3期282-286,共5页Journal of Shanghai Normal University(Natural Sciences)

基　　金：上海市教育委员会科研创新项目(09Y164;08Y270);上海师范大学一般科研项目(SK200721);上海师范大学前瞻性科研项目(DYL200903)

摘　　要：为了避免薯蓣皂甙元-3β-乙酸酯溴加成反应中C-23溴代副产物的产生,系统考察了有机碱和环氧化合物对它溴加成反应的影响.由于有机碱和环氧化合物均可消除反应体系中存在的酸,从而有效地抑制溴加成反应中C-23溴代副产物的产生,给出方便合成5,6-二溴代薯蓣皂甙元-3β-乙酸酯的方法.还考察了5,6,23-三溴代薯蓣皂甙元-3β-乙酸酯的脱溴反应条件,当在乙酸中用锌粉处理三溴代薯蓣皂甙元-3β-乙酸酯时得到全部脱溴产物;当在乙醇中用碘化钾处理三溴代薯蓣皂甙元-3β-乙酸酯时,仅得到5,6-脱溴产物.The influences of the organic base and epoxide on the bromine addition reaction of diosgenin 3β - acetate were investigated in order to restrain the formation of C - 23 brominarion by - product. The presence of either base or epoxide reduce the formarion of C - 23 breminarion via eliminating the acid in reaction system. In addition, the reglo - selective debrominarion of 5, 6, 23 - tribromodiosgenin - 3β - acetate was examined. The reaction between 5, 6, 23 - tribromediosgenin - 3β - acetate with zinc in acetic acid led to diosgenin 3β - acetate. Howere, when it reacted with potassium iodide, only the bromineatoms an 5, 6 - posirions, leading to 23 -bromodiosgenln 3β -acetate products.

关 键 词：薯蓣皂甙元-3β-乙酸酯 加成反应 选择性脱溴反应 

分 类 号：O629.2[理学—有机化学]