快速获得螺旋环氧醇类化合物:应用非对称的催化 [3 + 2] 三甲基甲循环添加
Journal of the American Chemical Society
|October 3, 2013
概括
研究人员合成了markfortines,这些复杂的天然产品具有抗虫活性. 该研究详细介绍了马克福林B的新型合成路径和马克福林C的第一个不对称合成,确定了关键的立体中心.
科学领域:
- 有机化学 有机化学
- 自然产品的合成自然产品的合成
- 药用化学 医学化学
背景情况:
- 马克福丁是复杂的二次代谢产物,具有显著的虫杀伤性.
- 它们的独特结构具有一个与螺旋oxindole核心融合的bicyclo[2.2.2]diazaoctane.
研究的目的:
- 报告了两个马克福丁家族成员的合成.
- 开发有效的合成策略,以获取这些复杂的分子.
- 为了实现马克福林天然产品的第一个不对称合成.
主要方法:
- 碳氧化TMM循环添加用于螺旋环芯结构.
- 内分子迈克尔添加和氧化基循环化用于双循环系统的形成.
- 不对称的蓝替代TMM循环添加用于立体选择性合成.
主要成果:
- 通过TMM循环添加和随后的循环化,成功合成了马克福丁B.
- 开发了第一个具有高产量和选择性的 (−) - 马克福丁C的非对称合成.
- 在 (−) - 马克福丁C.中建立所有立体中心的奇拉中心利用的演示.
结论:
- 已经建立了马克福丁的新型合成途径.
- 开发的方法提供了复杂的自然产品与潜在的治疗应用.
- 非对称的合成为探索马克福丁的结构-活性关系开辟了道路.
相关概念视频
Cycloaddition Reactions: Overview
Cycloadditions are one of the most valuable and effective synthesis routes to form cyclic compounds. These are concerted pericyclic reactions between two unsaturated compounds resulting in a cyclic product with two new σ bonds formed at the expense of π bonds. The [4 + 2] cycloaddition, known as the Diels–Alder reaction, is the most common. The other example is a [2 + 2] cycloaddition.
Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation
Robinson annulation is a base-catalyzed reaction for the synthesis of 2-cyclohexenone derivatives from 1,3-dicarbonyl donors (such as cyclic diketones, β-ketoesters, or β-diketones) and α,β-unsaturated carbonyl acceptors. Named after Sir Robert Robinson, who discovered it, this reaction yields a six-membered ring with three new C–C bonds (two σ bonds and one π bond).
Cycloaddition Reactions: MO Requirements for Thermal Activation
Thermal cycloadditions are reactions where the source of activation energy needed to initiate the reaction is provided in the form of heat. A typical example of a thermally-allowed cycloaddition is the Diels–Alder reaction, which is a [4 + 2] cycloaddition. In contrast, a [2 + 2] cycloaddition is thermally forbidden.
[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.
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
The Diels–Alder reaction is one of the robust methods for synthesizing unsaturated six-membered rings. The reaction involves a concerted cyclic movement of six π electrons: four π electrons from the diene and two π electrons from the dienophile.

![Solid-phase Synthesis of [4.4] Spirocyclic Oximes](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F58508.jpg&w=3840&q=50)
