Synthesis 2006(15): 2515-2522  
DOI: 10.1055/s-2006-942464
PAPER
© Georg Thieme Verlag Stuttgart · New York

Synthesis of Isoxazole-5-carboxylates by Cyclization of Oxime 1,4-Dianions with Diethyl Oxalate

Tuan Thanh Danga,b, Uwe Albrechtb, Peter Langer*a,c
a Institut für Chemie, Universität Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
Fax: +49(381)4986412; e-Mail: peter.langer@uni-rostock.de;
b Institut für Biochemie, Universität Greifswald, Soldmannstr. 16, 17487 Greifswald, Germany
c Leibniz-Institut für Katalyse e. V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059 Rostock, Germany
Further Information

Publication History

Received 7 December 2005
Publication Date:
04 July 2006 (online)

Abstract

The cyclization of oxime dianions with diethyl oxalate afforded 4,5-dihydro-5-hydroxyisoxazole-5-carboxylates, which were transformed into isoxazole-5-carboxylates by acid-mediated dehydration. The reaction of the dilithiated oximes of cycloheptanone and cyclooctanone resulted in the formation of 1,2-oxazin-6-ones rather than isoxazoles.