Synthesis 2005(17): 2875-2880  
DOI: 10.1055/s-2005-872205
PAPER
© Georg Thieme Verlag Stuttgart · New York

Ex Chiral Pool Synthesis of (-)-Siphonarienone from a Methyl-Branched Wax Ester

Yana Galeyevaa, Michael Morrb, Sabine Laschat*a, Angelika Baroa, Manfred Nimtzb, Florenz Sasseb
a Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
b Gesellschaft für Biotechnologische Forschung, Mascheroder Weg 1, 38124 Braunschweig, Germany
e-Mail: sabine.laschat@oc.uni-stuttgart.de;
Further Information

Publication History

Received 11 April 2005
Publication Date:
23 August 2005 (online)

Abstract

Both optically pure siphonarienal (-)-1 and siphonarienone (-)-2 are accessible from the enantiopure precursor methyl (2R,4R,6R,8R)-2,4,6,8-tetramethylundecanoate 5. The latter was converted into the corresponding methyl 2-undecenoate 9 which either provided aldehyde (-)-1 by reduction and subsequent Swern oxidation of the unsaturated alcohol 10 or gave ketone (-)-2 via Weinreb amide 11 and its conversion with EtMgBr. Alternatively, ketone 2 can be obtained from siphonarienal (-)-1 in a two-step reaction.