Transformations of the tetracyclic skeleton of eudistomins by neighboring-group participation in the Mitsunobu reaction
作者:Jan H. van Maarseveen、Elna H. H. Oberyé、Marjon B. Bolster、Hans W. Scheeren、Chris G. Kruse
DOI:10.1002/recl.19951140107
日期:——
tetracyclic ring system, now with a 1,5,2-oxathiazine ring. Substitution of the hydroxyl group in a trans 1-hydroxy dethia carba eudistomin derivative (i.e. with a 1,2-oxazepine ring) also gave rearranged products due to transannular interaction from the bridgehead nitrogen atom, to give via an aziridinium ion intermediate, products with a 6,5,7,6-membered tetracyclic ring system containing an 1,2-oxazine
Mitsunobu反应介导将氮亲核试剂引入反式1-羟基eudistomins中,从而获得高收率的重排产物,而不是由于邻近基团的参与而导致的预期的cis eudistomins。在1,6,2-oxathiazepine环中的硫原子在6,5,6,7元四环系统中进行环过相互作用,生成含硫th离子的中间体,随后本亲核分子的分子间攻击得到一个6,5,6,6元四环系统,现在带有1,5,2-恶二嗪环。在所涉及的羟基的取代反式1-羟基去硫卡巴eudistomin衍生物(即 (具有1,2-氧杂氮杂环的化合物)也由于桥头氮原子的跨环相互作用而产生了重排产物,并通过叠氮鎓离子中间体提供了具有6,5,7,6-元四环体系的产物,其中1, 2-恶嗪环。