The core structure of the RNA polymerase inhibitor tagetitoxin has been synthesized by one-carbon ring expansion of bridged bicyclic monothioacetals. The key steps are intramolecular ylide formation by reaction between the sulfur atom and a pendant diazoester, followed by an efficient photochemical 1,2-rearrangement to give the desired 9-oxa-3-thiabicyclo[3.3.1]nonane ring system.
RNA聚合酶
抑制剂tagetitoxin的核心结构已通过桥联的双环单
硫缩醛的一碳环扩展合成。关键步骤是通过
硫原子与侧基重氮酸酯之间的反应形成分子内叶立德,然后进行有效的光
化学1,2-重排,得到所需的9-氧杂-3-噻二环[3.3.1]
壬烷环系统。