Steroids. Part 43. Thermal decomposition of steroidal azidoformates

Abstract

Thermolysis of the four possible isomeric 3-methoxy-16-methylestra-1,3,5(10)-trien-17-yl azidoformates 1b, 6b, 10b and 14b, of 3-methoxyestra-1, 3, 5(10)-trien-17β-yl azidoformate 17b, and of 16β-azidoformyloxymethyl-3-methoxyestra-1,3,5(10)-triene 21b was realized at 100 °C. Thermolysis results in insertion of the nitrene intermediate into C–H bonds, the site of which depends on the steric position of the substituents in the D ring of the sterane skeleton.