一种合成 (+) - 撒西托辛的合成
1Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA.
Journal of the American Chemical Society
|March 23, 2006
概括
研究人员开发了一种新的非对称合成 (+) -saxitoxin (STX),一个强大的神经毒素. 这种方法利用了新型的异环中间体,使得研究离子通道的药理学工具有价值.
科学领域:
- 有机化学 有机化学
- 神经科学是一个神经科学.
- 药理学 药理学是指药理学的学科.
背景情况:
- 萨西托克辛 (STX) 是一种强大的神经毒素,可以选择性地阻断电压通道.
- 复杂的STX结构对化学合成提出了重大挑战.
- 了解STX的作用机制需要获得天然产品及其类似物.
研究的目的:
- 开发一种新的 (+) - 撒克西托克辛 (STX) 的不对称合成方法.
- 为了展示oxathiazinane二氧化异环在合成复杂的氨基衍生物中的实用性.
- 提供STX和相关化合物的获取,作为离子通道研究的药理学工具.
主要方法:
- 从一个N,O-乙前体开始的不对称合成.
- 使用硫酸盐的C-H氨基化来制备前体.
- 使用二氧化氧化氧化异循环组装多功能氨基.
- 一个九个环环的瓜尼丁中间体的氧化和脱水循环.
主要成果:
- 实现了 (+) - 撒克西托辛 (STX) 的完全不对称合成.
- 合成路线突出显示了二氧化氧化异循环的有效性.
- 一个关键的九个成员环guanidine中间体成功地循环形成三环核.
- 合成提供了一种可靠的方法来访问STX和类似物.
结论:
- 开发的合成途径提供了有效的 (+) -saxitoxin.
- 这项工作表明了在复杂分子合成中oxathiazinane二氧化异循环的多功能性.
- 随着STX和类似物的可用性,将有助于进一步研究电压式通道.
相关概念视频
Synthesis and Decomposition Reactions
Synthesis and decomposition are two types of redox reactions. Synthesis means to make something, whereas decomposition means to break something. The reactions are accompanied by chemical and energy changes.
Conjugate Addition to α,β-Unsaturated Carbonyl Compounds
α,β-Unsaturated carbonyl compounds are molecules bearing a carbonyl and alkene functionality in conjugation with each other. The conjugation in the molecule leads to three resonance structures. The hybrid form exhibits two probable electrophilic sites: the carbonyl carbon and the β carbon.
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.
[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement
The Cope rearrangement is classified as a [3,3] sigmatropic shift in 1,5-dienes, leading to a more stable, isomeric 1,5-diene. The reaction involves a concerted movement of six electrons, four from two π bonds and two from a σ bond, via an energetically favorable chair-like transition state.
Aryldiazonium Salts to Azo Dyes: Diazo Coupling
The reaction of weakly electrophilic aryldiazonium (also called arenediazonium) salts with highly activated aromatic compounds leads to the formation of products with an —N=N— link, called an azo linkage. This reaction, presented in Figure 1, is known as diazo coupling and occurs without the loss of the nitrogen atoms of the aryldiazonium salt. Highly activated aromatic compounds such as phenols or arylamines favor the diazo coupling reaction. The coupling generally occurs at the para position.
Radical Formation: Addition
Radicals can be formed by adding a radical to a spin-paired molecule. This is typically observed with unsaturated species, where the addition of a radical across the π bond leads to the production of a new radical by dissolving the π bond. For example, the addition of a Br radical to an alkene yields a carbon-centered radical.
Similar to charge conservation in chemical reactions, spin conservation is implicit for radical reactions. Accordingly, the product formed must possess an unpaired...
Similar to charge conservation in chemical reactions, spin conservation is implicit for radical reactions. Accordingly, the product formed must possess an unpaired...


