The hexacyclic skeleton of himandrine (2), which is present in 15 of the more complex alkaloids obtained from the bark of the tropical rain forest tree Galbulimima belgraveana has been prepared by means of a 19-step synthesis beginning with the known [3.2.1]-benzobicyclooctene intermediate 9. An alternative approach is also described, thus far culminating in 34. Key transformations include Diels–Alder
从热带雨林树Galbulimima belgraveana的树皮中获得的15种较复杂的
生物碱中存在的山and碱(2)的六环骨架已通过从已知的[3.2.1]开始的19步合成方法制备]-苯并双环
辛烯中间体9。还描述了一种替代方法,到目前为止达到了34。关键的转变包括Diels-Alder环加成,环收缩,Curtius重排,Birch还原,分子内亲核胺化和
钯介导的烯烃胺化。