title: Gas-liquid chromatographic studies of reactions and structural relationships of steroids. II. Positions 3, 11, and 20 in the 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 (WK), their conversion to hydroxyl groups by NaBH4(RD), and to dioxolone derivatives by ethylene glycol (DO); the conversion of hydroxyl to keto groups by CrO3 (OX), and to TMS ethers by hexamethyldisilazane; the hydrolysis of dioxolone and TMS derivatives by H+ (HY). GLC chromatograms of reaction mixtures of single and multistep reactions readily provide information on effects on functional groups at positions 3, 11, and 20 in the 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 computation methods is demonstrated.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D002849:Chromatography, Gas; D005026:Ethylene Glycols; D006868:Hydrolysis; D006914:Hydroxysteroids; D007664:Ketosteroids; D008433:Mathematics; D008832:Microchemistry; D011278:Pregnanes / Q000032:analysis* / Q000592:standards; D012825:Silicon; D013329:Structure-Activity Relationship
chemical_list: D005026:Ethylene Glycols; D006914:Hydroxysteroids; D007664:Ketosteroids; D011278:Pregnanes; D012825:Silicon