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.