Synthesis 2021; 53(13): 2201-2211
DOI: 10.1055/a-1385-9052
paper

Total Synthesis of the Natural Carbazoles O-Demethylmurrayanine and Murrastanine A, and of a C4,C4′ Symmetric Murrastanine A Dimer from N-Phenyl-4,5-dimethylene-1,3-oxazolidin-2-one

José Luis Avila-Melo
,
Adriana Benavides
,
Alfredo Fuentes-Gutiérrez
,
Joaquín Tamariz
,
H.A.J.-V. and J.T. thank SIP-IPN for financial support through grants 20151591, 20160567, 20160791, 20171928, 20170902, 20181307, 20180198, 20196462, 20195228, 20202433, and 20200227. J.T. gratefully acknowledges CONACYT (grants 178319, A1-S-17131, and 300520) for financial support.


Abstract

The synthesis of natural carbazoles O-demethylmurrayanine and murrastanine A starting from the title exo-heterocyclic diene­ is described. In the synthesis of murrastanine A, its symmetric C4,C4′ dimer can be obtained as the sole product under rather mild conditions. In all cases, the key intermediate is the same diarylamine. The carbazole nucleus is obtained through a Pd-promoted cyclization of the appropriate diarylamine. For the synthesis of O-demethylmurrayanine, the cyclization takes place on a silylated derivative. The crystal structures of murrayanine, two diarylamines, and two non-natural carbazole intermediates are also presented.

Supporting Information



Publication History

Received: 06 December 2020

Accepted after revision: 08 February 2021

Accepted Manuscript online:
08 February 2021

Article published online:
01 March 2021

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