エクテインアシジンの全合成 743
Jinchun Chen1, Xiaochuan Chen, Michèle Bois-Choussy
1Institut de Chimie des Substances Naturelles, CNRS, 91198 Gif-sur-Yvette Cedex, France.
Journal of the American Chemical Society
|January 5, 2006
まとめ
研究者は,5つの主要な構成要素を用いて,エクテインアシジン743の収束した全合成を達成しました. この複雑な有機合成には,特定のフェニララノール誘導体から始まり,全体で3%を生産する23のステップが必要でした.
科学分野:
- 有機化学 オーガニック・ケミストリー
- 合成化学 合成化学とは
- 薬用化学 薬用化学について
背景:
- エクテインアシジン743は,重要な抗がん作用を持つ強力な海洋天然製品です.
- 効率的な合成経路の開発は,エクテインアシジン743のような複雑な分子へのアクセスと研究に不可欠です.
研究 の 目的:
- 743. エクテインアシジンの収束した全合成を確立する.
- 簡単に手に入るビルディングブロックを使用して,実用的なルートを実演します.
主な方法:
- 5つの主要な構成要素を採用したコンバージェント・シンセシス戦略.
- l-3-ヒドロキシ-4-メトキシ-5-メチルフェニララノールから始まる多段階の反応配列.
- 中間製品と最終製品の浄化と特徴付け.
主要な成果:
- エクテインアシジン743分子フレームワークの構築に成功しました.
- 合成には23の異なる化学的変異が関与しました.
- トータル・シンセシスで,全体の3%の総収量を達成しました.
結論:
- 開発されたコンバージェントアプローチは,エクテインアシジン743の合成に有効な経路を提供します.
- この合成は,複雑な海洋天然製品の組み立ての実現可能性を強調しています.
- さらに最適化することで,潜在的な治療用途の全体的な収量も改善される可能性があります.
関連する概念動画
¹H NMR: Complex Splitting
A proton M that is coupled to a proton X results in doublet signals for M. However, NMR-active nuclei can be simultaneously coupled to more than one nonequivalent nucleus. When M is coupled to a second proton A, such as in styrene oxide, each peak in the doublet is split into another doublet.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied first.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied first.
Structure of Conjugated Dienes
Introduction
Conjugated dienes are compounds characterized by the presence of alternating double and single bonds. In a conjugated system like 1,3-butadiene, the unhybridized 2p orbital on each carbon overlaps continuously, allowing the π electrons to be delocalized across the entire molecule. In contrast, this type of overlap does not occur in cumulated and isolated dienes, such as 2,3-pentadiene and 1,4-pentadiene, respectively. Instead, the π electrons remain localized between the double...
Conjugated dienes are compounds characterized by the presence of alternating double and single bonds. In a conjugated system like 1,3-butadiene, the unhybridized 2p orbital on each carbon overlaps continuously, allowing the π electrons to be delocalized across the entire molecule. In contrast, this type of overlap does not occur in cumulated and isolated dienes, such as 2,3-pentadiene and 1,4-pentadiene, respectively. Instead, the π electrons remain localized between the double...
Method of Sections: Problem Solving I
Consider a symmetrical roof truss structure, composed of vertical, diagonal, and horizontal members. The length of each horizontal member is 4 m. The lengths of the vertical members FB and HD are 4 m, while the length of member GC is 6 m. The loads acting at joints F, G, and H are 2 kN, while those at joints A and E are 1 kN.
EDTA: Conditional Formation Constant
Each EDTA molecule has six binding sites: four carboxyl groups and two amino groups. The fully protonated form of EDTA is represented as H6Y2+. However, it can exist in different forms, H5Y+, H4Y, H3Y−, H2Y2−, and HY3−, depending on the pH of the solution. In very basic solutions with pH > 10.17, the fully deprotonated form, Y4−, is the predominant species that readily complexes with metal ions in a 1:1 ratio.
For the equilibrium reaction of the metal with the Y4− form of EDTA, the formation...
For the equilibrium reaction of the metal with the Y4− form of EDTA, the formation...
EDTA: Auxiliary Complexing Reagents
EDTA titrations are usually carried out in highly basic conditions, where the fully deprotonated form of EDTA, Y4−, actively complexes with the free metal ions in the solution. Several metal ions precipitate as hydrous oxide (hydroxides, oxides, or oxyhydroxides) under these conditions, lowering the concentration of free metal ions in the solution. For this reason, auxiliary complexing agents or ligands such as ammonia, tartrate, citrate, or triethanolamine are used in EDTA titrations to...
Aggregate Cement Ratio
The Aggregate Cement ratio refers to the weight of aggregate divided by the weight of cement in a concrete mix. Altering this ratio has profound effects on the concrete's properties. This ratio plays a pivotal role in determining the strength, workability, and durability of concrete. When the Aggregate Cement ratio is higher, the mix is leaner, meaning it has less cement paste to lubricate the aggregate, potentially making the concrete less workable. Such mixes, known as lean, enhance the...


