Gas chromatography–mass spectrometry of the stereoisomers of heterocyclic compounds. Part 2b.1 Perhydroxanthenes

Abstract

The quantitative relationships between the retention of the stereoisomers of perhydroxanthene (PHX) on a column packed with graphitized thermal carbon black (GTCB) and their hypothetical molecular structures optimized by molecular mechanics have been established. From the GC-MS data obtained the structure of four novel stereoisomers have been elucidated. Along with the theoretically expected trans-anti-trans-, trans-syn-cis-and cis-anti-cis-isomers, the unusual stable stereoisomeric form of PHX has been found and elucidated as conformer B of the cis-syn-cis-isomer. The evidence for this assignment based on the obtained GC-and MS-data is discussed.

Molecular statistical calculation of thermodynamic characteristics of adsorption of O-, S-, and Se-containing heteroadamantanes on graphitized thermal carbon black

“…25 For example, the conformational composition, separation on the GTC, and identification by chromatography coupled with mass spec trometry of stereoisomeric perhydrothioxanthenes, per hydroxanthenes, and perhydro 4 thia s indacenes have been studied earlier. 24,[33][34][35] Good agreement between the experimental and theoretically calculated TCA values (in particular, К 1,С and q -dif,1 ) for diverse stereoisomers was established 24,33-35 when the earlier 27,28 determined AAP parameters were used in the form of Eq. (2).…”

Gas chromatography–mass spectrometry of the stereoisomers of heterocyclic compounds. Part 3.† Perhydro-4-thia-s-indacene

“…[10][11][12] The atomic coordinates of adsorbate molecules, required by this method, were obtained after energy minimization of their hypothetical structures by molecular mechanics according to the approach successfully tried out earlier. 6,7,12 This results in plots of the dependence of ln K 1 on the reciprocal temperature 1/T which are shown in Fig. 4.…”