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反式-3,4-二取代琥珀酰亚胺的合成及(3S,5R,8S,9S)-3-丁基-5-丙基-8-羟基吲哚里西啶生物碱和包公藤甲素的全合成

Synthetic Studies on Trans-3,4-Disubstituted Succinimides and the Asymmetric Total Synthesis of (3S,5R,8S,9S)-3-Butyl-5-Propyl-8-Hydroxyindolizidine and (-)-Bao Gong Teng A

【作者】 林耿杰

【导师】 黄培强;

【作者基本信息】 厦门大学 , 有机化学, 2009, 博士

【摘要】 含有3,4-二取代琥珀酰亚胺结构的天然产物以及吲哚里西啶生物碱、托品烷类生物碱广泛分布于自然界中,它们大多具有重要的生物活性。其中,包公藤甲素是自然界中发现的第一个具有拟胆碱活性的托品烷类生物碱。在眼科临床上,作为缩瞳剂被应用于青光眼的治疗。而最近分离得到的生物碱(3S,5R,8S,9S)-3-丁基-5-丙基-8-羟基吲哚里西啶28,是第一个报导的环上羟基取代的蚂蚁毒素生物碱,它的相关生理活性还未被测试。这些化合物分别代表着天然产物中的三种结构特征,因此本论文的目的在于研究和建立合成含有这些结构的化合物的新方法。取得的主要结果如下:一、研究了苯甲酰化的苹果酰亚胺衍生物在SmI2作用下的Reformatsky类型反应。采用Barbier条件,反应温和、产率高,并取得了较高的立体选择性。通过单晶X射线衍射确定反应产物21d的相对构型,并提出了相应的机理对环外选择性加以解释。二、从L-苹果酸出发以立体发散的方式合成3,4-二取代琥珀酰亚胺及其对映体。三、从手性合成子86出发,经过格氏加成、硼氢化鋅立体选择性还原、Mitsunobu-Staudinger反应制备顺式-5,6-二取代己内酰胺99a。化合物99a是制备含有顺式-5-羟基-6-烷基取代哌啶结构天然产物的重要中间体。四、从商品化的(S)-焦谷氨酸甲酯108出发,经过七步反应完成8-羟基吲哚里西啶28的全合成,总产率28.9%。关键步骤使用亲电环化反应的方法高立体选择性地引入哌啶环C-8位羟基。值得一提的是,所有反应步骤都具有高的化学选择性、区域选择性或者立体选择性。这是为数不多的将该方法用于含有3-羟基哌啶醇结构生物碱的合成五、从酰亚胺147出发,经过11步反应,以7.58%的总产率完成了包公藤甲素的不对称合成。其关键步骤使用SmI2作为单电子还原剂进行分子内亚胺鎓离子与醛的偶联反应,以此构筑托品环骨架,C-2位手性碳的立体选择性为11:1。无编改内容

【Abstract】 The 3,4-disubstituted succinimide substructure-containing natural products andindolizidine alkaloids, tropane alkaloids are widespread in nature. Most of themexhibit important bioactivities. Among them,(-)-Bao Gong Teng A was the firsttropane alkaloid found in nature which exhibited cholinergic activity. In clinicalophthalmology, it has been used to treat glaucoma as the miotic agent. Recentlyisolated indolizidine alkaloid 28 was the first reported ring-hydroxylatedacetate-derived ant venom alkaloid. Although the bioactivity of this indolizidinealkaloid has not yet been studied, it has been reported to be involved in ant warfare.For the synthesis of these bioactive natural products, the aim of this dissertation isexploring new methods for the construction of these structure skeleton. The mainresults and observations from these studies are listed as follows:1.A highly trans-stereoselective SmI2-induced Reformatsky-type reaction of4-substituted-O-benzoylated malimides with carbonyl compounds was performedwith excellent yield. The stereochemistry of compound 21d was determined by singlecrystal X-ray crystallographic analysis and a plausible mechanism for thestereoselective reaction was proposed. 2. An enantiodivergent strategy for the synthesis of trans-3,4-disubstitutedsuccinimides was accomplished. Such a synthetic strategy was achieved by distinctlyusing the dianion aldol-type reaction or the Seebach’s protocol in the malimideformation step.3. Starting from the building block 86, the cis-5,6-disubstitutedlactam 99a wassynthesized. 4. A seven-step synthesis of (3S,5R,8S,9S)-3-butyl-5-propyl-8-hydroxyindolizidine(28), an ant venom alkaloid isolated from Myrmicaria melanogaster, was disclosedwith an overall yield of 28.9%. The key feature of the synthesis is the use of theiodocarbamoylation for the introduction of the hydroxyl group of the 3-piperidinol.Remarkably, all the reaction steps proceeded with excellent chemo-, regio-, and/ ordiastereo-selectivities. To the best of our knowledge, while electrophile-mediatedheterocyclization reaction is a popular methodology for the synthesis of heterocyclies,its use in the stereoselective installation of the 3-piperidinol hydroxyl group is rare. 5. Starting from imide 147, a 11-step synthesis of(-)-Bao Gong Teng A was disclosedwith an overall yield of 7.58%. The key step was the SmI2 mediated intramolecularcoupling of the iminium ion with the aldehyde, which constructed the tropaneskeleton with a diastereoselectivity of 11:1 at C-2 carbinol..

  • 【网络出版投稿人】 厦门大学
  • 【网络出版年期】2009年 11期
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