Synthesis 2017; 49(02): 275-292
DOI: 10.1055/s-0036-1588322
paper
© Georg Thieme Verlag Stuttgart · New York

Palladium-Catalyzed Synthesis of Pyrayaquinones, Murraya­quinones, and Murrayafoline-B

Sebastian K. Kutz
Department Chemie, Technische Universität Dresden, Bergstraße 66, 01069 Dresden, Germany   Email: hans-joachim.knoelker@tu-dresden.de
,
Arndt W. Schmidt
Department Chemie, Technische Universität Dresden, Bergstraße 66, 01069 Dresden, Germany   Email: hans-joachim.knoelker@tu-dresden.de
,
Hans-Joachim Knölker*
Department Chemie, Technische Universität Dresden, Bergstraße 66, 01069 Dresden, Germany   Email: hans-joachim.knoelker@tu-dresden.de
› Author Affiliations
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Publication History

Received: 08 August 2016

Accepted after revision: 06 September 2016

Publication Date:
11 October 2016 (online)


Dedicated to Professor Dieter Enders on the occasion of his 70th birthday.

Abstract

We describe the total synthesis of murrayafoline-B and seven carbazole-1,4-quinone alkaloids. A palladium(II)-catalyzed oxidative cyclization is used to construct the carbazole skeleton. Pyran annulation and oxidation provide pyrayaquinone-A, -B, and -C. DIBAL-H-promoted reductive ring opening of pyrano[3,2-a]carbazole precursors leads to the prenylated and geranylated carbazole-1,4-quinone alkaloids murrayaquinone-B, -C, -D, and -E and to murrayafoline-B.

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