A synthetic strategy for the preparation of the isoquinolinequinone antibiotic safracin A (1a) is outlined. Our initial strategy for the construction of the ABC ring was based on a retrosynthetic analysis. Conversion of 5 in five steps to the imide 16 vas followed by a 1,2-reduclion with lithium tri-tert-butoxyaluminum hydride to give the allylic alcohol 7a. This compound was then cyclized to the 1
概述了制备
异喹啉醌抗生素safracin A(1a)的合成策略。我们构建ABC环的最初策略是基于逆合成分析。将五步中的5转化为
酰亚胺16 vas,然后用三叔丁氧基
氢化铝锂进行1,2-还原,得到烯丙基醇7a。然后将该化合物环化为1,5-亚
氨基-3-苯并佐辛8a和
茚并[1,2-b]
吡嗪-2-酮17。不需要的异构体17被转化为N-甲基四环内酰胺21,其结构通过X射线晶体学确定。转换18以九个步骤完成对五环
丙酮酰胺31的合成。最后,对31进行两步氧化脱甲基,以提供醌10a和34。还描述了将羟基引入醌10a或34的CI位置上的失败尝试。