Synthesis 2009(4): 591-596  
DOI: 10.1055/s-0028-1083343
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

A Regioselective Route to 5-Substituted Isoxazole- and Isoxazoline-3-phos­phonates

Paola Conti*, Andrea Pinto, Lucia Tamborini, Petra Dunkel, Veniero Gambaro, Giacomo L. Visconti, Carlo De Micheli
Dipartimento di Scienze Farmaceutiche ‘P. Pratesi’, Università degli Studi di Milano, Via Mangiagalli 25, 20133 Milano, Italy
Fax: +39(2)50319326; e-Mail: paola.conti@unimi.it;
Further Information

Publication History

Received 2 October 2008
Publication Date:
27 January 2009 (online)

Abstract

5-Substituted 3-(diethoxyphosphoryl)isoxazoles and -2-isoxazolines were synthesized regioselectively by 1,3-dipolar cycloaddition of (diethoxyphosphoryl)formonitrile oxide to monosubstituted alkynes and alkenes. By applying this methodology to an N-(tert-butoxycarbonyl)-substituted allylglycine methyl ester, we prepared the precursors of two diastereomeric 3-phosphono-2-isoxazolin-5-yl-substituted amino acids, which are bioisosteres of potent NMDA receptor antagonists.

1

On leave from Semmelweis University, Budapest, Hungary