• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Studies on nitrogen-containing secondary metabolites from terrestrial and marine origin: Part I. Enzymatic epoxidation of 2,5-dihydroxyacetanilide in Streptomyces sp. Part II. Synthesis of marine sponge alkaloids: Slagenins, axinohydantoins, and studies towards the pyrrolopiperazine system in the agelastatin core.
【24h】

Studies on nitrogen-containing secondary metabolites from terrestrial and marine origin: Part I. Enzymatic epoxidation of 2,5-dihydroxyacetanilide in Streptomyces sp. Part II. Synthesis of marine sponge alkaloids: Slagenins, axinohydantoins, and studies towards the pyrrolopiperazine system in the agelastatin core.

机译：陆生和海洋来源的含氮次生代谢产物的研究：第一部分。链霉菌属中2,5-二羟基乙酰苯胺的酶促环氧化。第二部分海洋海绵生物碱的合成：Slagenins，Axinohydantoins，以及在astlastatin核心中对吡咯烷哌嗪系统的研究。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Part I. A deuterium exchange analysis of 2,5-dihydroxyacetanilide (5) in the absence and presence of DHAE II was performed to test the nucleophilicity of the substrate in the absence and presence of catalyst. In addition, inhibition studies using 1,4-dihydroxybenzene were performed to determine the role that the N-acetyl side chain group plays in the formation of a stable substrate-enzyme complex. 1,4-Dihydroxybenzene was found to be a weak inhibitor, indicating that the N-acetyl functionality may play a crucial role in forming stable enzyme-substrate interactions. The synthesis of dihydroquinoline 7 was pursued to investigate the enzyme substrate interactions between DHAE and a substrate where the N-acetyl side chain has been fixed to a particular orientation. Efforts towards formation of the C6-C7 bond as a key step in the synthesis of dihydroquinoline 7 using palladium couplings, organocuprates, Lewis acid catalysts, and aza-Claisen reactions were pursued. To complement the results obtained, the electron distribution in amide 21 was calculated using Semi Empirical methods. The results revealed that the electron density in the aromatic ring is centered around C4, suggesting that this is the most nucleophilic carbon in the ring.; Part II. Slagenins A (1), B (2), and C (3) were synthesized by β-functionalization of olefin 14. The desired tetrahydrofuroimidazolidin-2-one system was achieved by intramolecular oxidative addition of alcohol 4 to the imidazolone ring. When this reaction was carried out in the presence of methanol slagenins B (2) and C (3) were obtained in good yield. Heating 2 and 3 in aqueous acid gave slagenin A (1) as the sole product. (Z)-debromoaxinohydantoin (17 ) was synthesized by intramolecular cyclization of α-methoxy imidazolone 11b under acidic conditions followed by a double oxidation reaction to furnish the hydantoin-lactam functionality. These conditions were originally developed for a practical synthesis of the related alkaloid (Z)-debromohymenialdisine (20). A series of acid and base catalyzed reactions of imidazoles bearing an α-β unsaturated system or a β-halogen functionality showed that cyclizations via an SN2 path favor formation of an oxazoline ring system. Preliminary studies using pyrrolocarboxamideacetals suggest that β-ketone 73 would be an appropriate substrate for the formation of the pyrrolopyrazine system in the agelastatins.
机译：第I部分。在不存在和存在DHAE II的情况下，对2,5-二羟基乙酰苯胺（ 5 ）进行氘交换分析，以测试在不存在DHAE II的情况下底物的亲核性和催化剂的存在。此外，进行了使用1,4-二羟基苯的抑制研究，以确定 N -乙酰基侧链基团在稳定的底物-酶复合物的形成中所起的作用。发现1,4-二羟基苯是一种弱抑制剂，表明 N -乙酰基官能团可能在形成稳定的酶-底物相互作用中起关键作用。进行二氢喹啉 7 的合成以研究DHAE和 N -乙酰基侧链已固定在特定方向上的底物之间的酶底物相互作用。寻求形成C6-C7键的步骤，该步骤是使用钯偶联，有机铜酸盐，路易斯酸催化剂和aza-Claisen反应合成二氢喹啉 7 的关键步骤。为了补充获得的结果，使用半经验方法计算了酰胺 21 中的电子分布。结果表明，芳环中的电子密度以C4为中心，表明这是环中最亲核的碳。 Part II。 Slagenins A（ 1 ），B（ 2 ）和C（ 3 ）合成如下：烯烃 14 的β-官能化。通过将醇 4 分子内氧化加到咪唑啉酮环上，可以得到所需的四氢呋喃并咪唑啉-2-酮体系。当该反应在甲醇slagenins存在下进行时，以高收率获得了B（ 2 ）和C（ 3 ）。在酸性水溶液中加热 2 和 3 ，将制得的slagenin A（ 1 ）作为唯一的产品。通过在酸性条件下α-甲氧基咪唑酮 11b 的分子内环化反应，然后进行双氧化反应，合成了（ Z ）-地溴代肟基乙内酰脲（ 17 ）。提供乙内酰胺的功能。这些条件最初是为实际合成相关生物碱（ Z ）-去溴膜十二烷（ 20 ）而开发的。一系列带有α-β不饱和体系或β-卤素官能团的咪唑在酸和碱的催化下的反应表明，通过S 2 途径的环化有利于恶唑啉环体系的形成。使用吡咯并羧酰胺缩醛的初步研究表明，β-酮 73 将是在astlastatins中形成吡咯并吡嗪系统的合适底物。

著录项

  • 作者

    Barrios Sosa, Ana Carolina.;

  • 作者单位

    Oregon State University.;

  • 授予单位 Oregon State University.;
  • 学科 Chemistry Organic.
  • 学位 Ph.D.
  • 年度 2002
  • 页码 304 p.
  • 总页数 304
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 有机化学;
  • 关键词

相似文献

  • 外文文献
  • 中文文献
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号