Synthesis 2006(18): 3043-3047  
DOI: 10.1055/s-2006-950190
PAPER
© Georg Thieme Verlag Stuttgart · New York

Synthesis of Polycitrin A and 3,4-Bis(4-hydroxyphenyl)pyrrole Derivatives Related to Polycitone A

Christian Winklhofer, Andreas Terpin, Christian Peschko, Wolfgang Steglich*
Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13 (F), 81377 München, Germany
Fax: +49(89)218077756; e-Mail: wolfgang.steglich@cup.uni-muenchen.de;
Further Information

Publication History

Received 22 May 2006
Publication Date:
15 August 2006 (online)

Abstract

The oxidative condensation of 3-arylpyruvic acids with arylethylamines to give 3,4-diarylpyrrole-2,5-dicarboxylic acids was used for an efficient synthesis of polycitrin A (4). Investigation of the bromine-mediated degradation of acid 2b to maleimide 3b suggested that 2,5-dibromopyrrole (5) and 5,5-dimethoxy-3-pyrroline-2-one (6) are intermediates in this process. The debromo analogue of polycitone A (10) was prepared in two steps from pyrrole dicarboxylic acid diester 7.