Synthesis 2015; 47(06): 807-816
DOI: 10.1055/s-0034-1379640
paper
© Georg Thieme Verlag Stuttgart · New York

3-Aryl-5-vinyl-2-isoxazolines and 3-Aryl-5-vinylisoxazoles from Aryl Nitrile Oxides and Methyl Vinyl Ketone Lithium Enolate: Reaction Limits and Synthetic Utility Exploitation

Antonio Salomone
a   Dipartimento di Farmacia-Scienze del Farmaco Università degli Studi di Bari ‘A. Moro’, Via E. Orabona 4, 70125 Bari, Italy   Email: paola.vitale@uniba.it
b   Consorzio Interuniversitario Nazionale Metodologie e Processi Innovativi di Sintesi (CINMPIS) Università degli Studi di Bari ‘A. Moro’, Via E. Orabona 4, 70125 Bari, Italy
,
Antonio Scilimati
a   Dipartimento di Farmacia-Scienze del Farmaco Università degli Studi di Bari ‘A. Moro’, Via E. Orabona 4, 70125 Bari, Italy   Email: paola.vitale@uniba.it
,
Paola Vitale*
a   Dipartimento di Farmacia-Scienze del Farmaco Università degli Studi di Bari ‘A. Moro’, Via E. Orabona 4, 70125 Bari, Italy   Email: paola.vitale@uniba.it
› Author Affiliations
Further Information

Publication History

Received: 22 September 2014

Accepted after revision: 17 November 2014

Publication Date:
18 December 2014 (online)


Dedicated to Claudio Salomone, born November 24, 2014

Abstract

3-Aryl-5-hydroxy-5-vinyl-2-isoxazolines were synthesized by reacting aryl nitrile oxides with the lithium enolate of methyl vinyl ketone (MVK) at –78 °C. Fair to good yields are obtained in the case of aryl nitrile oxides bearing electron-withdrawing groups on the aryl moiety or less bulky groups. Conversely, lower yields or no reaction was observed in the presence of hindered aryl nitrile oxides. Such a behavior was confirmed by ab initio calculations of the activation energies for three reactions. A number of 3-aryl-5-vinylisoxazoles were quantitatively obtained by dehydration/aromatization of the corresponding 5-hydroxy-2-isoxazolines under acidic conditions. The side-chain elaboration is reported as a synthetic utility of some vinylisoxazoles and vinylisoxazo­lines.

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