Synfacts 2007(4): 0445-0445  
DOI: 10.1055/s-2007-968301
Polymer-Supported Synthesis
© Georg Thieme Verlag Stuttgart · New York

Solid-Phase Synthesis of 3,5-Disubstituted Isoxazoles

Contributor(s): Yasuhiro Uozumi, Toshimasa Suzuka
Y.-G. Wang, W.-M. Xu, X. Huang*
Zhejiang University, Hangzhou and Shanghai Institute of Organic Chemistry, P. R. of China
Further Information

Publication History

Publication Date:
23 March 2007 (online)

Significance

A simple method for preparation of 3,5-disubstituted isoxazoles by using polystyrene-supported vinyl selenide was developed. Thus, polystyrene-supported selenenyl bromide 1 was prepared according to the reported procedures (K. C. Nicolaou, J. Pastor, S. Barluenga, N. Wins­singer Chem. Commun. 1998, 1947-1948). The reaction of resin 1 with ethyl acrylate followed by treatment of the resulting resin 2 with t-BuONa gave vinyl selenide resin 3. The [3+2] cycloaddition reactions of resin 3 with nitrile oxides generated in situ from oximes 4, NCS, and Et3N afforded the corresponding polymeric isoxazoles 5. Treatment of resin 5 with H2O2 gave 3,5-disubstituted isoxazoles 6a-e (80-89% yield with >92% purities from 3) (eq. 1).