Bromoquinone–enaminone annulations: syntheses of murrayaquinone-A and (±)-bismurrayaquinone-A

WS Murphy, M Bertrand

Index: Murphy, William S.; Bertrand, Martial Journal of the Chemical Society - Perkin Transactions 1, 1998 , # 24 p. 4115 - 4119

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Citation Number: 45

Abstract

A total synthesis of the carbazolequinone alkaloid, murrayaquinone-A was achieved by an initial annulation of the N-benzyl enamine 8 with 2-methyl-5-bromobenzoquinone 6. Shapiro deoxygenation–olefination followed by heating with DDQ resulted in the exclusive formation of N-benzylmurrayaquinone-A 16. Debenzylation proved very difficult but was finally achieved by heating briefly in trifluoroacetic acid with a catalytic quantity of ...