著者

高野 誠一 畑山 範 高橋 召 高橋 洋子 岩田 裕光 宍戸 宏造 小笠原 国郎

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.21, pp.50-57, 1978

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A new synthetic approach to the alkaloids related to emetine (3) and quinine(5) from norbornylene(1) is described. Norbornylene(1) was transformed into (±)-norcamphor(2) which was oxidized to the bicyclic lactone(8) by Baeyer-Villiger oxidation then alkylated with ethyl bromide and allyl bromide in a stereospecific fashion to give (9) and (29), respectively. The former lactone(9) was converted into the emetine precursor(21) and protoemetinol(4) both in dl form via the α-diketone monothioketal (13). The latter lactone(29) was converted into the homomeroquinene equivalent(37) via the α-diketone monothioketal(32) which was then transformed into dl-meroquinene aldehyde(6) via the olefin formation through the phenylselenide(41). Since norbornylene(1) has been converted into a chiral norcamphor(2), the present method would be applicable to the synthesis of the above alkaloids together with various indole alkaloids in a chiral form.