Abstract:

Using hydrochloric acid,ferric chloride and hydrochloric acid-ferric trichloride as catalyst,the epimerization of sesamin and asarinin were preliminary investigated and attempt to probe into the possible mechanism.The structure of the composite was identified by NMR and MS.The results showed that the reaction reach to equilibrium with 20% hydrochloric acid;it didn't work with only ferric trichloride as catalyst which was easy to hydrolysis; Using hydrochloric acid-ferric chloride as catalyst,use less quantity(the mass fraction of 0.05%-0.5%)can achieve better catalytic effect,reaction temperature should be above the boiling point of the reaction system of ethanol,reaction can be completed within 10 min.Combined catalyst to reduce the activation energy of the reaction system,accelerate the sesamin isomerization process for asarinin.

Key words: sesamin, asarinin, chemical reaction, synthesis, epimerization, catalyst, catalytic mechanism

摘要：

分别以盐酸、三氯化铁、盐酸-三氯化铁作为催化剂,研究芝麻素差向异构化合成细辛素的条件并探讨差向异构化机理,采用NMR、MS方法对合成物进行结构鉴定。结果显示:单独使用盐酸作为催化剂,盐酸体积分数为20%时催化反应达到平衡;单独使用三氯化铁作为催化剂,会发生水解反应,致使催化反应终止;以盐酸-三氯化铁作为联合催化剂,使用较少的量(质量分数0.05%~0.5%),反应温度控制在体系中乙醇沸点之上,10 min内就能够达到很好的催化效果。联合催化剂可降低反应体系的活化能,加快了芝麻素异构化为细辛素的进程。

关键词: 芝麻素, 细辛素, 化学反应, 合成, 差向异构化, 催化剂, 催化机理