EFFICIENT SYNTHESIS OF BIOACTIVE NATURAL PRODUCTS EMPLOYING CATALYTIC CASCADE REACTIONS.

近年来，催化级联反应因其环保、经济等优点而受到广泛关注。在本研究中，作者研究了无锡级联同烯丙基-同烯丙基自由基重排过程和镍催化级联电还原环化方案。(1)无锡级联纯烯丙基-纯烯丙基自由基重排法合成血清芬地酸A和B血清芬地酸A和B是2002年从胎牛血清中分离得到的神经保护剂。这种独特的结构是由双环[2.2.2]辛烷环体系组成的，它带有一个不寻常的亚砜侧链。血清芬地酸是全合成的有吸引力的目标，不仅因为它们的神经保护活性，而且因为它们的结构具有9个立体中心和atisane框架的挑战。本研究完成了(-)-血清芬迪酸a和B的全合成。采用无锡级联全烯丙基-全烯丙基自由基重排的方法构建双环[2.2.2]辛烷环体系。这里开发的方法应该提供获得血清芬迪酸的合成类似物的途径。(2)级联电还原环化三环[6.2.1.0^<1,6>]十一烷-4- 1及相关多环化合物的一锅组装通过碳-碳成键过程在一次操作中组装多环分子是有机合成的一个重要方向。因此，近年来，各种类型的级联反应得到了积极的发展。在本研究中，作者提出了一种基于分子内级联电还原环化的策略，并成功应用于三环[6.2.1.0^<1,6>]十一烷-4- 1及相关多环化合物的构建。这种新方案的优点是成本低，以及电化学的毒理学和环境友好特性。少

Recently, the development of catalytic cascade reactions has attracted considerable attention because cascade reactions are environmentally friendly and economical. In this research, the author has examined tin-free cascade homoallyl-homoallyl radical rearrangement process and Ni-catalyzed cascade electroreductive cyclization protocol.(1)Total Synthesis of Serofendic Acids A and B Employing Tin-Free Cascade Homoallyl-Homoallyl Radical RearrangementSerofendic acids A and B are neuroprotective agents that were isolated from fetal calf serum in 2002. The unique structures were shown to consist of bicyclo[2.2.2]octane ring system bearing an unusual sulfoxide side chain. The serofendic acids are attractive targets for total synthesis, not only due to their neuroprotective activity, but also because of the challenge of their structures, which feature nine stereocenters and atisane framework. In this research, a total synthesis of both (-)-serofendic acids A and B has been accomplished. The s … More ynthetic strategy involved the use of a tin-free cascade homoallyl-homoallyl radical rearrangement for the construction of bicyclo[2.2.2]octane ring system. The methodology developed here should provide access to synthetic analogues of serofendic acids.(2)One-Pot Assembly of Tricyclo[6.2.1.0^<1,6>]undecane-4-one and Related Polycyclic Compounds by Cascade Electroreductive CyclizationThe assembly of polycyclic molecules through carbon-carbon bond-forming processes in a single operation is a significant direction for organic synthesis. Therefore, various types of cascade reactions have been actively developed in recent years. In this research, the author has developed a strategy based on intramolecular cascade electroreductive cyclization, and the cascade electroreductive cyclization has been successfully applied to the construction of tricyclo[6.2.1.0^<1,6>]undecane-4-one and related polycyclic compounds. The favorable profile of this novel protocol is increased by the low cost as well as the toxicologically and environmentally benign character of electrochemistry. Less