A facile synthetic approach towards 6/6/5/5-tetracyclic spiroheterocycles has been developed from the highly diastereoselective 1,3-dipolar cycloaddition reaction of [e]-fused 1H-pyrrole-2,3-diones with nitrones. The described novel heterocyclic systems are heteroanalogs of cytotoxic alkaloids, kibalaurifoline and gitingensine. The developed reaction represents the first example of involvement of 1H-pyrrole-2,3-diones fused at [e]-side in a 1,3-dipolar cycloaddition reaction.

中文翻译：

---

通过1 H-吡咯-2,3-二酮与硝酮的稠合反应的1,3-偶极环加成反应，轻松地制备生物碱样6/6/5 / 5-四环螺杂环

从[ e ]稠合的1 H-吡咯-2,3-二酮与硝酮的高度非对映选择性1,3-偶极环加成反应，已经开发出一种简便的合成方法，用于合成6/6/5 / 5-四环螺杂环。所描述的新型杂环系统是细胞毒性生物碱，奇巴拉妥林和gitingensine的杂类似物。发达的反应代表了1 H-吡咯-2，3-二酮在[ e ]侧融合在1，3-偶极环加成反应中的第一个例子。