title: Evidence of formation of isomeric methoximes from 20-oxosteroids.
abstract: The formation and gas chromatographic behavior of syn- and anti-isomers in position 20 of the methoxime-trimethylsilyl (MO-TMS) derivatives of many 20-oxo and 3,20-dioxo-21-hydroxysteroids is reported. The existence of such isomers was established from the gas chromatographic (GC) and mass spectrometric analysis of the MO-TMS derivatives of 3 alpha,21-dihydroxy-5 beta-pregnan-20-one and its 17 alpha-epimer. The degree of separation during GC analysis of the syn- and anti-isomers in position 20, as well as those in position 3, is associated to the position of additional hydroxyl groups on the steroid ring. These data are very important for the location of oxygenated substituents such as 2 alpha/2 beta, 6 alpha/6 beta, 11 beta, 16 alpha, 17 alpha, 18, 19 or 21-hydroxyl groups during structural studies of 20-oxo and 3,20-dioxosteroids.
authors.affiliation: Laboratoire de Biochimie des Interactions Cellulaires, Faculté de Sciences, Université de Bourgogne, Dijon, France.
authors.forename: P
authors.initials: P
authors.lastname: Bournot
authors.forename: L C
authors.initials: LC
authors.lastname: Ramirez
mesh_terms: D002849:Chromatography, Gas; D003900:Desoxycorticosterone / Q000031:analogs & derivatives*; D008401:Gas Chromatography-Mass Spectrometry; D007536:Isomerism; D010091:Oximes
chemical_list: D010091:Oximes; D003900:Desoxycorticosterone; C009413:tetrahydrodeoxycorticosterone