Synthesis 2007(19): 3061-3067  
DOI: 10.1055/s-2007-983901
PAPER
© Georg Thieme Verlag Stuttgart · New York

Synthesis of s-Indacene Derivatives by Double Robinson-Type Cyclopentene Annulation

Yawei Zhang, Jens Christoffers*
Institut für Reine und Angewandte Chemie, Universität Oldenburg, Carl von Ossietzky-Str. 9-11, 26111 Oldenburg, Germany
Fax: +49(441)7983873; e-Mail: jens.christoffers@uni-oldenburg.de;
Further Information

Publication History

Received 4 May 2007
Publication Date:
11 September 2007 (online)

Abstract

Michael reactions of 2,5-dioxocyclohexane-1,4-dicarboxylates with methyl vinyl ketone yield bis-adducts that can be further cyclized in a Robinson-type annulation to give s-indacene derivatives as single diastereomers. The carboxylate functions of this scaffold can be deprotected and subsequently decarboxylated to yield tricyclic products with a central aromatic ring.