A Formal Total Synthesis of (±)-Cephalotaxine Using Sequential <i>N</i>-Acyliminium Ion Reactions
作者:Yuji Koseki、Hiroto Sato、Yumi Watanabe、Tatsuo Nagasaka
DOI:10.1021/ol017114f
日期:2002.3.1
[reaction: see text] Novel synthesis of cephalotaxine 1 based on tertiary N-acyliminium ion chemistry starting from alkynylamide 2 was achieved. The key steps include the preparation of pyrroloisoquinoline 4 from alkynylamide 2, the ring expansion of pyrroloisoquinoline 4 to pyrrolobenzazepine 12, and the construction of cyclopentapyrrolobenzazepine ring system 6, all of which are derived from N-acyliminium
[反应:见正文]从叔乙酰胺2开始,基于叔N-嘧啶离子化学合成了头孢他辛1。关键步骤包括从炔基酰胺2制备吡咯并异喹啉4,吡咯并异喹啉4到吡咯并苯并enza庚因12的扩环以及环戊吡咯并并苯并氮杂卓环体系6的构建,所有这些均来自N-酰基酰亚胺离子中间体。