著者

海原 浩辰 林 尚毅 横島 聡 藤間 達哉 井上 将行 福山 透

出版者

天然有機化合物討論会実行委員会

雑誌

天然有機化合物討論会講演要旨集 第59回天然有機化合物討論会実行委員会 (ISSN:24331856)

巻号頁・発行日

pp.163-168, 2017 (Released:2020-09-20)

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Asymmetric total synthesis of (–)-morphine (1) has been accomplished in 18 steps from commercially available 7-methoxy-2-tetralone (7). Our synthesis features a simple transformation from the readily available chiral intermediate (3), reported earlier by d’Angelo and co-workers. Introduction of the requisite oxygen functionality to the 8-position of the tetralone could be achieved by Friedel-Crafts acylation and ensuing Baeyer-Villiger oxidation. Upon treatment of dienol 15 with acid at 0 °C, a facile cyclization proceeded to form the E-ring (16). The diene thus formed was later converted to γ-hydroxy-α,β-unsaturated ketone 20 by means of photooxygenation and triethylamine. Dehydration of 20 was effected by triflic anhydride and subsequent removal of 2,4-dinitrobenzenesulfonyl group generated a mixture of neopinone (21) and codeinone (22). Conversion of the mixture to (–)-morphine was performed by following the known procedures.

著者

彦根 悠人 長友 優典 井上 将行

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.81, no.12, pp.1136-1149, 2023-12-01 (Released:2023-12-13)

参考文献数

95

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Resiniferatoxin (1) belongs to a daphnane diterpenoid family, and has strong agonistic effects on TRPV1, a transducer of noxious temperature and chemical stimuli. The densely oxygenated trans-fused 5/7/6-tricarbocycle (ABC-ring) of 1 presents a daunting challenge for chemical synthesis. We accomplished three radical-based total syntheses of 1 to streamline the overall route. In the first-generation synthesis, we implemented a novel radical three-component coupling reaction. This transformation formed the hindered linkage between the A and C-rings and extended the carbon chain in a stereoselective fashion. The 7-membered B-ring was cyclized by the second radical reaction. In the second-generation synthesis, we improved the efficacy and practicality by reorganizing the reaction sequence and retaining the intermediates of the first route. Thus, we utilized intermolecular radical allylation, Stille coupling, and photocatalytic decarboxylative radical cyclization as the three key transformations. In the third-generation synthesis, we designed a specific intermediate based on the common substructure of not only 1, but also structurally related diterpenoids, and established a unified strategy. The common intermediate was efficiently built by exploiting the bridgehead radical cyclization and derivatized into 1 through efficient C-ring functionalizations. These three total syntheses of 1 together demonstrate the advantages of radical reactions for linking hindered bonds within carbocycles without damaging preexisting functionalities, thereby offering a new strategic design for multi-step target-oriented synthesis.

著者

臼杵 豊展 井上 将行 平間 正博 田中 俊之 細井 文仁 大家 真治 大谷 敏夫

出版者

天然有機化合物討論会実行委員会

雑誌

天然有機化合物討論会講演要旨集

巻号頁・発行日

vol.45, pp.257-262, 2003

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The antitumor antibiotic C-1027 is a 1:1 complex of a highly labile enediyne chromophore (1) and a carrier apoprotein. C-1027 exhibited the potent cytotoxicity toward various cancer cells. The p-benzyne biradical (2), which is in equilibrium with 1, abstracts hydrogens from DNA to exert its biological activity. The apoprotein functions as both the stabilizer and the drug delivery system of 1. Recently, we found that the biradical 2 slowly abstracts α-proton of Gly96 of the apoprotein, which caused the oxidative cleavage of the peptides and led to a self-degradation of C-1027. To create a more stable analog of antibiotic C-1027, we designed a Gly96-deuterated (D-Gly) apoprotein. The D-Gly apoprotein was expressed in Escherichia coli in the presence of glycine-d_5. The unstable chromophore 1, isolated from natural C-1027, was then incorporated into the D-Gly apoprotein using HPLC techniques to obtain the D-Gly C-1027. Stability tests revealed that the D-Gly C-1027 was 1.8 and 4.9 times as stable as the natural one under solid and solution states, respectively. Cytotoxicity test also reflected the stability of D-Gly C-1027. Thus, we achieved the creation of supranatural products by rational design utilizing kinetic isotope effect. The presented work demonstrated the novel design principle to create the supra-natural products by integrating the data of physicochemical property of the small molecule and the atomic-level 3D-structure of the protein, which will be applicable to other biologically important natural products and proteins.

著者

W.H. Brown [ほか] 著 井上将行 [ほか] 訳

出版者

東京化学同人

巻号頁・発行日

2014