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Updated: Jul 9, 2026
14:18
A Strategy for Sensitive, Large Scale Quantitative Metabolomics
Published on: May 27, 2014
セムポロシドaのエナチオセレクティブ全合成
Paolo Piccinini1, Giovanni Vidari, Giuseppe Zanoni
1Dipartimento di Chimica Organica, Università di Pavia, Italy.
Journal of the American Chemical Society
|April 22, 2004
まとめ
セムペロシドAの新しい10段階の合成により,このイリドオイドグリコシドの最初の完全合成が得られる. この方法は,複雑な構造を効率的に作成し,その立体化学を確認します.
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
- 自然製品合成 自然製品合成
背景:
- セムペロシドAは,独特のグルコシル化イリダン構造を有しています.
- イリドオイドグリコシドは,多様な生物学的活動を持つ重要な種類の天然製品です.
- 複雑なイリドオイドグリコシドの合成は,特にステレオ化学とグルコシデーションの制御において,課題を提示します.
研究 の 目的:
- セムペロシドAの簡潔でエナンチオセレクティブな合成戦略を開発する.
- セムペロシドAの最初の完全合成を確立する.
- セムペロシドAの絶対的立体化学を明確に証明する.
主な方法:
- Hg (II) 媒介の電愛性ヘテロアトムサイクリングを用いた新しい合成経路の開発.
- C-2およびC-3ステレオセンターのステレオ選択式設置.
- エナティオメリックに純粋なラクトンを,出発材料として利用する.
主要な成果:
- セムペロシドAの最初の完全合成を10ステップで達成しました.
- 全体の17%のリターンを得ました.
- イリダンの骨格の形成中のステレオ化学をうまく制御した.
結論:
- 開発された戦略は,セムポロシドAの合成に多用途で効率的です.
- この合成は,イリドオイド・グリコシド合成におけるヘミアセタル・グルコシデーションに関連する課題を克服しています.
- セムペロシドAの絶対的立体化学は,明確に確認されています.
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関連する概念動画
01:15Carboxylic Acid Derivatives: Overview
Carboxylic acid derivatives are formed by replacing the hydroxyl group of carboxylic acids with a different functional group. The most common carboxylic acid derivatives are:
01:28Structures of Carboxylic Acid Derivatives
Structure of Carboxylic Acid Derivatives
Carboxylic acid derivatives contain an acyl group attached to a heteroatom such as chlorine, oxygen, or nitrogen. The carbonyl carbon and oxygen are both sp2-hybridized with an unhybridized p orbital.
The three sp2 orbitals of the carbonyl carbon form three σ bonds, one each with the carbonyl oxygen, the α carbon, and the heteroatom, whereas the other two sp2 orbitals of the carbonyl oxygen are occupied by the lone pairs. Further, the unhybridized p...
Carboxylic acid derivatives contain an acyl group attached to a heteroatom such as chlorine, oxygen, or nitrogen. The carbonyl carbon and oxygen are both sp2-hybridized with an unhybridized p orbital.
The three sp2 orbitals of the carbonyl carbon form three σ bonds, one each with the carbonyl oxygen, the α carbon, and the heteroatom, whereas the other two sp2 orbitals of the carbonyl oxygen are occupied by the lone pairs. Further, the unhybridized p...
01:07Acid Halides to Amides: Aminolysis
Aminolysis is a nucleophilic acyl substitution reaction, where ammonia or amines act as nucleophiles to give the substitution product. Acid halides react with ammonia, primary amines, and secondary amines to yield primary, secondary, and tertiary amides, respectively.
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...
01:19Amines to Amides: Acylation of Amines
Various carboxylic acid derivatives (such as acid chlorides, esters, and anhydrides) can be used for the acylation of amines to yield amides. The reaction requires two equivalents of amines. The first amine molecule functions as a nucleophile and attacks the carbonyl carbon to produce a tetrahedral intermediate. This is followed by the loss of the leaving group and restoration of the C=O bond.
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary amide...
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary amide...
01:19Composition of Polyprotic Acid Solutions as a Function of pH
Polyprotic acids of the type H2M constitute two ionizable protons. As a result, on titration with a base, they exhibit two equivalence points in the titration curve. During titration, the species H2M, HM−, and M2− will be present in the solution at different points. The fractions of H2M, HM−, and M2− present at the various instances of the titration are denoted by α0, α1, and α2, respectively.
A graph with the alpha values is plotted against the volume of base added during titration. Here, a...
A graph with the alpha values is plotted against the volume of base added during titration. Here, a...
01:29Amino Acid Biosynthetic Pathways
Amino acid biosynthesis is essential for cell growth, protein synthesis, and metabolic regulation. Cells generate essential and non-essential amino acids from metabolic intermediates to sustain vital biological functions. These intermediates originate from key metabolic pathways: glycolysis, the tricarboxylic acid (TCA) cycle, and the pentose phosphate pathway. Important precursors include α-ketoglutarate, pyruvate, oxaloacetate, phosphoenolpyruvate, and erythrose-4-phosphate, which provide...