哌啶生物碱(+)-Febrifugine、(-)-Deoxoprosophylline和大袋蛾性信息素的不对称合成

【作者】 刘如成；

【导师】 林国强；

【作者基本信息】 复旦大学 ， 有机化学， 2009， 博士

【摘要】 天然产物是指来自天然的动物、植物和微生物的化学物质。许多天然产物都具有重要生物活性,目前临床应用的药物有一半左右均来自天然产物或其衍生物。而天然产物大多数都是手性化合物,且含量都比较少。因此,采用不对称化学合成的方法,合成出光学活性的物质,无论从理论上还是实践上都具有重大的意义。本论文的工作包括以下几部分内容:1、探索了Lewis酸催化条件下N,O-缩醛与烯醇硅醚的不对称烷基化反应。首先以廉价的L-谷氨酸为原料,经12步反应制备了N,O-缩醛结构2-47,以单边苄基保护后计算,总收率为13%。然后在Lewis酸催化条件下,进行一系列烯醇硅醚底物的扩展,结果表明在C-3位TBSO诱导的条件下,可选择性的在哌啶环C-2位进行烷基化反应,产物的dr值最高可达96:4,烷基化产物的构型为顺式。应用此研究结果,对具有抗疟活性的我国药用生物碱常山碱2-1进行了不对称合成。2、在本课题组已有的研究基础上，进一步拓展了二碘化钐催化条件下叔丁基亚磺酞亚胺与醛的偶联反应的研究。实验结果表明在二碘化钐催化下，叔丁基磺酞亚胺与具有γ-羰基官能团（酯、酮）的醛可进行选择性反应，收率可达到80%以上，dr值则大于99:1。因此，以此反应为关键反应，本论文进一步完成了3-羟基呱啶类生物碱(-)-deoxoprosophylline 3-1的不对称合成。3、大袋蛾性信息素的首次不对称合成和绝对构型确定的研究大袋蛾俗称布袋虫,又名大蓑蛾,属鳞翅目,蓑蛾科。在我国的华北、华东、华中、西南、西北地区均有分布。该虫对蔷薇科、豆科、杨柳科、胡桃科及悬铃木科植物危害最重,是果树和城市园林植物的常见害虫之一。传统的化学农药防治具有害虫抗药性增强、破坏生态平衡、大量农药残留于环境而引起食物链累积等等诸多缺陷,而一度被誉为病虫害防治的“第三代农药”指的就是信息素。2006年林国强等人通过GC-EAD和GC-MS分离检测得到了大袋蛾性信息素，并初步描述其结构为3,13-二甲基十五酸-1-乙基-2-甲基丙酯(1-ethyl-2-methylpropyl3-13-dimethylpentadecanoate)，并指出该结构中醇部分的构型为S构型，而另外两个手性中心的立体化学尚未确认。本论文以丁酰氯为起始原料，采用Evans辅基来构筑带有甲基的直链中的两个手性中心的构型，再经Wittig反应等共23步反应，分别合成了大袋蛾性信息素的四个光学异构体4-1(a-d),目前正等待时机进行活性测试。■■更多还原

【Abstract】 Natural products - a term used commonly in reference to chemical substances found in nature are end products of secondary metabolism of plants, animals or microorganism. Most natural products possess a variety of important bioactivities and about half of the clinic drugs come from natural products or their derivatives. Natural products are almost chiral compounds and their concentration in nature is low. So preparation of natural products through asymmetric synthetic method is important both academically and in practice.This dissertation is constituted by the following three parts:1 The asymmetric alkylation of N,O-acetal with silyl enol ethers catalyzed by Lewis acid is investigated. We obtain the N, O-acetal 2-47 after 12 steps from L-glutamatic acid and the total yield is 13%. The results of alkylation of 3-silyloxy-2-acyloxypiperidine 2-47 with a range of silyl enol ethers indicate that the nucleophilic substitution in the presence of BF₃·OEt₂ give the product in cis-diastereoselectivity with high diastereoselectivity （up to 96:4）. Based on the results of nucleophilic substitution of 2-47 with silyl enolate, （+）-Febrifugine 2-1, an antimalarial alkaloid, is successfully synthesized.2 On the basis of our previous works on cross-coupling of N-tert-butanesulfinyl imines with aldehyde to form unsymmetrical vicinalβ-amino alcohols, we investigate the situation that the reactant aldehyde is one withγ-carbonyl. The results show that the cross-coupling of aldehyde withγ-carbonyl with N-tert-butanesulfinyl imines goes smoothly in over 80% yield and high diastereoselectivity （dr > 99:1）. On the basis of this study, （-）-deoxoprosophylline 3-1 is successfully synthesized.3 Clania variegata Snellen, belonging to Psychidae, is widely distributed in North China, East China and Center China etc. It is one of common insect pests on fruit trees and landscape plants, heavily harming the plants of posaceae, leguminosa, salicaceae, walnut family and platanaceae. The traditional method to prevent and control plant diseases and to eliminate pests is to use pesticide. But it not only strengthens pests’ drug resistance, destroys ecological equilibrium, but also makes the accumulation of residue of pesticide in food chain to harm people. Pheromone is once praised as "The Third Generation Pesticide". The major component of the sex pheromone of Paulownia bagworm, Clania variegate was reported to （1’S）-1-ethyl-2-methyl-propyl 3-13-dimethylpentadeca-noate by Gries et al. As to the absolute configuration of this ester, they assigned S configuration to the alcohol part. But the absolute configuration of the two remaining stereogenic centers of the carboxylic acid part, however, has remained unkown. We synthesized the four stereoisomers of 4-1 after 23 steps starting from butyryl chloride. The stereochemistry of the carboxylic acid was constructed under the help of Evans’ auxiliaries. The tactile electromagnetic wave analyzer and field trapping experiments are going to be done at appropriate chance. Cl更多还原