Collect. Czech. Chem. Commun. 1998, 63, 1564-1574

Synthesis of 17β-Isoxazolyl Steroids and Spiro[steroid-17,2'-furanone]s

Alexander V. Baranovskya, Marinus B. Groenb, Aede de Grootc, Raissa P. Litvinovskayaa and Vladimir A. Khripacha

a Institute of Bioorganic Chemistry, National Academy of Sciences, Zhodinskaya str. 5/2, 220141 Minsk, Belarus
b Scientific Development Group, N. V. Organon, P.O. Box 20, 5340 BH Oss, The Netherlands
c Laboratory of Organic Chemistry, Agricultural University, Dreijenplein 8, 6703 HB Wageningen, The Netherlands


Synthesis of 17β-isoxazolyl steroids and their transformations into the corresponding spiro[steroid-17,2'-furanone]s are described. The reaction sequence consists of the 1,3-dipolar cycloaddition of a nitrile oxide to mestrenol, dehydration, epoxidation or dihydroxylation, cleavage of the isoxazole moiety and cyclization of intermediate enamino ketones.

Keywords: Steroids; Isoxazoles; Spiro[steroid-17,2'-furanone]s; Steroidal spirofuranones; Nitrile oxides.