【作者】 朱文举；

【导师】 王忠文；

【作者基本信息】 南开大学 ， 农药学， 2013， 博士

【摘要】 桥环骨架是一类十分重要并且广泛存在于天然产物中的分子骨架。桥环骨架根据不同的分类方法可以分为全碳桥环和碳杂原子桥环。我们这里主要探讨其中两类重要氧杂和全碳双环骨架：全碳双环[n.2.1](n=2,3,4)桥环骨架和氧杂[n.2.1](n=3,4)桥环骨架的合成和应用。有机合成化学家在过去的一百多年里,已经发展了大量构筑这两类环系的方法。近年来随着一些重要生理活性天然产物如GB.13和Platensimycin、EnglerinA等被不断的分离得到,桥环骨架的构筑方法及其相关天然产物全合成仍旧是有机合成领域的热门话题之一。环加成反应尤其是分子内环加成反应,具有较高的成键效率、良好的区域和立体选择性等优点,在复杂环系的构筑中扮演着十分重要的角色。我们希望通过研究环丙烷与不饱和化合物及其它张力环的分子内交叉环加成或串联重排环加成反应来发展通用高效的构筑桥环的方法,同时拓展其在复杂天然产物中的应用。本论文发展了环丙烷-1,1-双酯与烯烃的分子内交叉[3+2]环加成反应,实现了全碳桥环[n.2.1](n=2,3,4)骨架的通用高效构筑,并将这一构筑方法学成功应用于天然产物扁枝杉烯(Phyllocladane)的全合成中。同时环丙烷-1,1-双酯与环氧乙烷的分子内串联重排交叉[3+2]环加成反应,实现了氧杂桥环[n.2.1](n=3,4)骨架的通用高效构筑。这两类分子内交叉环加成反应均可在Lewis acid催化条件下进行,而环丙烷-1,1-双酯与环氧乙烷的分子内串联重排交叉[3+2]环加成反应还可在质子酸催化下进行,这两类反应都具有反应条件温和,底物范围广,产物结构多样等优点,通过底物的扩展,我们逐步建立了这两类桥环骨架的多样性分子库,这为以后发现相应的新医药和新农药先导化合物奠定了坚实的基础。更多还原

【Abstract】 Bridged ring skeleton is a class of very important molecular skeleton, and widely present in the natural product. Bridged ring skeleton contains carbocyclic skeletons and heterocyclic bridge ring divided according to different classification methods. We here mainly investigation synthesis and application of these two types of important bicyclic skeleton:bridged [n.2.1](n=2,3,4) carbocyclic skeletons and bridged [n.2.1](n=3,4) heterocyclic skeleton.In the past100years, Organic synthetic chemists has developed a number of methods to build these two types of ring systems. In recent years, with some important physiological activity of natural products such as GB.13and Platensimycin, Englerin A, etc. are constantly being isolated, the bridged ring skeleton building method and related total synthesis of the natural product is still the field of organic synthesis popular topic. Cycloadditions, especially the intramolecular cycloadditions with highly bonding efficiency, good regional and stereo selectivity, play an important role in the construction of complex cyclic skeletons. Our study based on intramolecular cross-cycloaddition or rearrangement cycloaddition reactions of cyclopropane with an unsaturated bond or the strained rings to development of general and efficient method of constructing bridge skeletons, at the same time expanding its applications in terpenoids and complex natural products.We have developed a novel intramolecular [3+2] cross-cycloadditions of cyclopropanes-1,1-diester with alkene. These reactions provided a general and efficient strategies for construcitions of bridged [n.2.1](n=2,3,4) carbocyclic skeletons and were successfully used to the total synthesis of Phyllocladane. At the same time, intramolecular [3+2] cross-cycloadditions of cyclopropanes-1,1-diester with epoxides,.These reactions provided a general and efficient strategies for construcitions of oxa-[n.2.1](n=3,4) bicyclic skeletons. These two types of intramolecular cross-cycloadditions can be catalyzed by Lewis acid, and the second type of reaction also can be catalyzed by protonicacid. all proceed on mild reaction conditions and have the broad scope of the substrates and have a diverse product structures. We have gradually established the diversity of molecular libraries of these two types of bridged skeletons, which will has laid a solid foundation for the later discovered new medicine and pesticide lead compound.更多还原