Gas—liquid chromatographic studies of reactions and structural relationships of steroids : Part III. 11α-hydroxysteroids of the androstane and pregnane series

Abstract

Qualitative and quantitative effects of classical reactions on steroids observed by gas—liquid chromatography (GLC) under standardized conditions, including the double internal-standard technique, are reported. Simple procedures applicable to nanogram amounts of reactants which afford excellent yields of the major products are described. Reactions studied include the Wolff—Kishner removal of keto groups, their conversion into hydroxyl groups with sodium—ethanol or sodium borohydride and into dioxolone derivatives with ethylene glycol; the conversion of hydroxyl into keto groups with chromium trioxide and to trimethylsilyl (TMS) ethers by hexamethyldisilazane; the hydrolysis of dioxolone and TMS derivatives by H +. Gas—liquid chromatograms of reaction mixtures of single- and multistep reactions readily provide information on the effects on the 11α-hydroxy and other functional groups at positions 3 and 17 (androstane series) and positions 3 and 20 (pregnane series), and the retention times of many steroids unavailable from commercial or other sources. GLC data analysis provides relationships between steroid structure and retention time from which methods for the computation of retention times and for steroid identification are designed. The accuracy of the calculation methods is demonstrated.