SYNTHESES AND MASS SPECTRAL REARRANGEMENTS OF UNSATURATED BIS-SULPHIDES AND BIS-SULPHONES

Abstract

Abstract The synthesis of (E)- and (Z)-1.2-bis(p-fluorophenylsulphenyl)stilbenes (2a and 2b) and 1,2-bis(p-fluorophenylsulphonyl)stilbenes (3a and 3b) was carried out and their configurations were consistent with their stereospecific synthesis. The isomeric 1,1-bis(p-fluorophenylsulphenyl)- and 1,1-bis(p-fluorophenylsulphonyl)-2,2-bis(phenyl)ethylenes (8 and 9) were also synthesised and configurations were established by degradative oxidation. Mass spectral rearrangements of all these compounds were examined. Mass spectra of 1,1-bis-sulphide and 1,1-bis-sulphone bears close relationship with those of (E)- and (Z)-isomeric counterparts. Smiles-type rearrangement observed in 1,2-bis-sulphides was absent in 1,2-bis-sulphones. McLafferty-type rearrangement involving hydrogen migration, from aryl group was noticed in both bis-sulphides and bis-sulphones. Vinyl migration to the sulphone oxygen predominates over aryl migration in three isomeric bis-sulphones. Key Words: (E)- and (Z)-I-p-fluorophenylsulphenylstilbenes(E)- and (Z)-1,2-bis(p-fluorophen-ylsulphenyl)stilbenes(E)-and(Z)-1,2-bis(p-fluorophenylsulphonyl)stilbenes(E)-and(Z)-1-p-fluorophenylsulphenyl-2-p′-fluorophenylsulphonylstilbenes1,1-Bis(p-fluorophenylsulphenyl)-2,2-bis(phen-yl)ethylene1,1-Bis(p-fluorophenylsulphonyl)-2,2-bis(phenyl)ethylene