天然有機化合物討論会講演要旨集
Online ISSN : 2433-1856
セッションID: 22
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22 Kifunensineおよび8-epi-kifunensineの合成(口頭発表の部)
茅切 浩笠原 千義高瀬 茂弘奥 照夫橋本 眞志
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会議録・要旨集 フリー

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Kifunensine(1) was isolated as a new immunomodulator with α-mannosidase inhibitory activity from an actinomycete, Kitasatosporia kifunense Na 9482. Its structure was deduced by detailed ^1H and ^<13>CNMR experiments and confirmed by X-ray crystal analysis. Kifunensine(1) corresponds to a cyclic oxamide derivative of 1-amino-substituted mannojirimycin. This unique structure of 1 prompted us to exploit the syntheses of 1 and 8-epi-kifunensine(3) related similarly to nojirimycin(5). Initially, construction of the simplest octahydro-2, 3-dioxoimidazo [1,2-a] pyridine system 11 consisting of the basic framework of 1 was investigated and this was achieved by a double cyclization of oxamide-aldehyde 9 to 11 with NH_3-M_2OH. Adoption of this method, as a key step, starting from D-mannosamine(13), led to an enantioselective synthesis of kifunensine(1) as shown in scheme III. The reaction probably proceeded via such a route as depicted in Scheme IV. For the synthesis of 8-epi-kifunensine(3), a similar cyclization of oxamide-hemiacetal 29 was attempted. How ever, the reaction never went to the desirable direction. On the other hand, when this cyclization was examined using 2, 4-dimethoxybenzylamine, the desired cyclization product 30 was obtained in a stereoselective manner. Oxidative removal of the benzyl group in 30 provided 8-epi-kifunensine(3) whose structure was confirmed by X-ray crystal analysis.

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© 1989 天然有機化合物討論会電子化委員会
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