Synthesis 2006(20): 3367-3369  
DOI: 10.1055/s-2006-950216
SHORTPAPER
© Georg Thieme Verlag Stuttgart · New York

A Palladium-Catalyzed Synthesis of Isoalliin, the Main Cysteine Sulfoxide in Onions (Allium cepa)

Jan C. Namyslo*, Claudia Stanitzek
Institut für Organische Chemie, TU Clausthal, Leibnizstr. 6, 38678 Clausthal-Zellerfeld, Germany
Fax: +49(5323)722834; e-Mail: namyslo@ioc.tu-clausthal.de;
Further Information

Publication History

Received 25 April 2006
Publication Date:
21 August 2006 (online)

Abstract

The natural sulfur compound isoalliin, (+)-(R)-3-[(E)-prop-1-enylsulfinyl]-2-aminopropanoic acid, was synthesized as a mixture of diastereomers in five steps from the hydrochloride of l-cysteine ethyl ester comprising an efficient - albeit unusual - Pd-catalyzed C-S coupling as the key step. Isoalliin is in demand in the field of Allium chemistry and serves as a standard for different determination methods in breeding research on Alliaceae, like onions, leek, or garlic.