著者
田中 耕作三世 小林 健一 古源 寛
出版者
公益社団法人 有機合成化学協会
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.77, no.7, pp.673-683, 2019-07-01 (Released:2019-07-08)
参考文献数
34
被引用文献数
3

(−)-L-755,807, which was isolated from an endophytic fungus, Microsphaeropsis sp., consists of a characteristic epoxy-γ-lactam ring and a tetraene-containing side chain, and exhibits bradykinin B2 receptor antagonist activity. The first total synthesis of (−)-L-755,807 was accomplished through a convergent approach, employing a late-stage coupling between the ring and side-chain segments. The ring segment was efficiently synthesized by a novel syn-selective Darzens reaction between di-tert-butyl bromomalonate and α-alkoxy aldehyde, and the side-chain segment was prepared by a highly stereoselective Horner-Wadsworth-Emmons reaction as a key step to construct the tetraene part. This synthesis enabled us to assign the relative and absolute configurations of (−)-L-755,807. Furthermore, we discovered an additional biological activity of this compound, namely, potent amyloid β aggregation inhibitory activity, which could be useful in the treatment of Alzheimer’s disease. The epoxy-γ-lactam moiety was identified as a likely pharmacophore for this activity. In this article, we describe the total synthesis, stereochemical assignment, and biological evaluation of (−)-L-755,807.
著者
鶴巻 英治
出版者
公益社団法人 有機合成化学協会
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.75, no.4, pp.360-361, 2017-04-01 (Released:2017-04-28)
参考文献数
10

Carborane acid is the strongest Brönsted acid presently known, possessing unusually high acidity greater than fluorosulfuric acid. Protonation by a carborane acid have proceeded effectively towards the weakest bases such as benzene, fullerene, alkanes, and even carbon dioxide, producing corresponding reactive cations as salts with the least coordinating carborane anion. This short-review highlights recent reports on structural elucidations of several important cations using a carborane acid.
著者
服部 弘
出版者
公益社団法人 有機合成化学協会
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.76, no.12, pp.1358-1359, 2018-12-01 (Released:2018-12-12)
参考文献数
13

Biocatalytic reactions are recently attracting attention as they offer various advantage over chemocatalysts and classical organic synthesis. Aided by the development of engineering techniques, such as site-directed mutagenesis and directed evolution, biocatalysts are modified to realize sustainable organic synthesis of API and natural products. In this mini review, recent applications of biocatalytic reactions in total synthesis of natural products are presented.
著者
古谷 敏行
出版者
公益社団法人 有機合成化学協会
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.59, no.5, pp.510-511, 2001-05-01 (Released:2009-11-13)
参考文献数
5
被引用文献数
1 2

筆者の所属する部門では原薬製造プロセスを研究しており, 新薬の効率的製法開発と既製品の工程改良による製造コスト削減を目指している。このなかで, 主に酵素反応と有機合成反応とを組み合わせた, いわゆるハイブリッドプロセスを基盤として研究を行っている。このような分野に従事してきたなかで, 最も強く関わってきたのがジルチアゼムの製法開発である。ジルチアゼムは, 田辺製薬 (株) で開発された冠血管拡張剤であり, 100ヵ国以上で販売され今なお世界的に高い評価を受けている。ここではジルチアゼムの製法開発例を通じて, 企業の研究者としてプロセス研究の進め方・考え方を披露したい。ジルチアゼムは1, 5-ベンゾチアゼピン骨格を有し, 2つの不斉炭素をもつため4種類の構造異性体が存在する。このうち主作用を有するものは (2S, 3S) 体であり, 当初から光学活性体として開発された。スキーム1に当社で開発した主な製造ルートを示す。当初の製造にはジアステレオマー光学分割法によって (2S, 3S) -3を得る方法が採用された。しかし, その後この方法は工程数が長いことと, 分割により大量の廃棄物が副生することから, さらに効率的な製法開発が要望された。一般に光学活性体の製造において, 後工程でラセミ化が起こらない限り, なるべく出発原料に近い段階でキラリティーを構築するのが, 生産効率・経済性・廃棄物処理の面で有利である。この考えに基づいて, transラセミ体として最初に不斉中心が現れる (2RS, 3SR) -グリシッド酸エステル2での光学分割に注目した。しかし, (2RS, 3SR) -2は, 酸・塩基の官能基をもたず, さらにベンゼン環に隣接して反応性に富むオキシラン環を有するため, ジァステレオマー誘導法などの光学分割は困難であった。
著者
山口 裕二 片桐 洋史
出版者
公益社団法人 有機合成化学協会
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.76, no.8, pp.820-827, 2018-08-01 (Released:2018-08-09)
参考文献数
41
被引用文献数
1

Azulene is a simple substance belonging to the class of compounds known as non-benzenoid aromatic hydrocarbons, and has attracted much attention because of its unusual properties, typified by large dipole moment and long-wavelength absorption properties. In this paper, we describe the synthesis, structures, properties, and organic field-effect transistor (OFET) characteristics of 2-azulenyl end-capped oligomers and 2,6-connected terazulene isomers. These compounds showed small transition energies due to their effective π-conjugation system, high-order orientations in the crystalline state, and typical OFET characteristics with high carrier mobilities. In particular, terazulene isomers reveal a unique π-conjugation system with an asymmetric distribution of molecular orbitals, which present an unconventional concept: polarity control of OFET achieved by molecular orbital distribution control. The molecular design, based on the 2,6-connected azulene-based π-conjugation, could be a key approach for constructing various semiconductor materials. Moreover, these findings provide a basis for accelerated development of the solid-state chemistry of azulene.
著者
池内 和忠 若森 晋之介 廣兼 司 山田 英俊
出版者
公益社団法人 有機合成化学協会
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.76, no.9, pp.904-913, 2018-09-01 (Released:2018-09-07)
参考文献数
83
被引用文献数
2

This review describes synthetic methods that have brought remarkable increase of synthesizable ellagitannins. Acquisition of capability to enable syntheses of all ellagitannins, which are more than 1,000 characterized natural products and their analogues, would contribute to development of understanding structure-activity relationship. The two major reasons diversifying the structures of ellagitannins are the presence of the hexahydroxydiphenoyl group and the C-O digallates, each of which arises through formation of a C-C or a C-O bond between two galloyl groups. To increase the number of synthesizable ellagitannins, establishment of methods for synthesizing these two components and for assembling the components to construct ellagitannin molecules are essential. Three focuses here are methods for synthesizing (1) the hexahydroxydiphenoyl group, (2) glucose derivatives with hexahydroxydiphenoyl bridges, and (3) the C-O digallates. In addition, several applications of these methods for total syntheses of ellagitannins are exemplified.
著者
天児 由佳
出版者
公益社団法人 有機合成化学協会
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.76, no.4, pp.358-359, 2018-04-01 (Released:2018-04-06)
参考文献数
11

PROTACs (proteolysis-targeting chimeric molecules), which comprise a target protein ligand, an E3 ubiquitin ligase ligand and a linker, induce selective degradation of the target protein by recruiting the E3 ubiquitin ligase. This approach is attracting attention as an alternative of traditional inhibitor-based therapeutics by small molecules. This review briefly summarizes the development and advances of PROTACs.
著者
島村 賢 高橋 基将 藤本 泰典 安岡 宏 伊藤 孝之
出版者
公益社団法人 有機合成化学協会
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.75, no.2, pp.121-133, 2017-02-01 (Released:2017-04-06)
参考文献数
42

(2-Deoxy-2-fluoro-4-thio-β-d-arabinofuranosyl)thymine (S-FMAU) was synthesized very efficiently from corresponding d-arabinofuranose derivative 16a which was available in bulk. Three important transforming methods were mainly described. One was the practical inversional bromination process for secondary alcohol generated by opening furanose ring. Another was the highly efficient thiofuranose synthesis via intramolecular carbonyl assisted SN2 reaction. And the last was the β-selective glycosylation process with thymine derivative. Applications of the thiofuranose synthesis using intramolecular carbonyl assist were also discussed.
著者
千葉 博之 田上 克也
出版者
公益社団法人 有機合成化学協会
雑誌
有機合成化学協会誌 (ISSN:00379980)
巻号頁・発行日
vol.69, no.5, pp.600-610, 2011-05-01 (Released:2011-07-11)
参考文献数
23
被引用文献数
11 21

HALAVENTM (eribulin mesylate, E7389) is a novel anticancer agent discovered and developed by Eisai, which was approved by the United States Food and Drug Administration (FDA) for the treatment of patients with metastatic breast cancer who have previously received at least two chemotherapeutic regimens for the treatment of metastatic disease. HALAVENTM is a non-taxane, microtubule dynamics inhibitor and a synthetic analog of halichondrin B, a natural product isolated from the marine sponge Halichondria okadai. Although the structure of HALAVENTM is substantially simplified relative to halichondrin B, the development of this complex molecule only by chemical synthesis represents a significant challenge in terms of pharmaceutical development. In this article, a developmental history of HALAVENTM from its discovery to process development aiming at commercial production is described.