Synthetic studies towards garsubellin A: synthesis of model systems and potential mimics by regioselective lithiation of bicyclo[3.3.1]nonane-2,4,9-trione derivatives from catechinic acid
作者:Nadia M. Ahmad、Vincent Rodeschini、Nigel S. Simpkins、Simon E. Ward、Claire Wilson
DOI:10.1039/b704311b
日期:——
an external quench method, various electrophiles have been incorporated at the C-5 bridgehead position in a one-step process that appears to be sensitive to the substitution pattern on the bicyclic system. Regioselective lithiation at the C-3 sp(2) centre was achieved by changing the base used from LDA to LTMP. Following the introduction of a prenyl substituent by bridgehead substitution, annulation
已经成功地在衍生自儿茶酸的底物上进行了桥头锂化反应,该底物具有存在于Garsubellin A中的双环[3.3.1]壬烷-1,3,5-三酮双环结构。使用外部猝灭方法,已引入了各种亲电试剂。一步法似乎对双环系统上的取代模式敏感的C-5桥头位置上的C桥键。在C-3 sp(2)中心的区域选择性锂化是通过将使用的碱从LDA更改为LTMP来实现的。在通过桥头取代引入异戊二烯基取代基之后,可以通过环氧化环的打开顺序使THF环环化,类似于garsubellin A中的环环化。儿茶酸核心中邻苯二酚取代基的氧化修饰有可能产生具有粘康酸的体系,