Two intermediates 9b and 9c already used by Cook and Magnus in their syntheses of indole alkaloids were obtained from the title compound 1 through a Fischer indolization procedure. Related tetracyclic intermediates 6 and 8 were also prepared: 6 having substituents at position 2 or 4 were directly obtained, while 8 with substituents at position 1 or 3 were selectively obtained through a convenient protection-deprotection scheme
库克和马格努斯在合成
吲哚生物碱时已经使用过的两种中间体 9b 和 9c,是通过费歇尔
吲哚化程序从标题化合物 1 中获得的。同时还制备了相关的四环中间体 6 和 8:直接得到了在 2 号或 4 号位置上有取代基的 6 号中间体,而在 1 号或 3 号位置上有取代基的 8 号中间体则是通过方便的保护-保护方案选择性地得到的。