FRAGMENTATION OF ORGANIC COMPOUNDS ON ELECTRON IMPACT .4. CYCLIC SULFONES

The mass spectra of nineteen cyclic sulfones are reported and fragmentation patterns are interpreted with the aid of high resolution mass measurements and deuterium labeling techniques. Sulfolane, monosubstituted sulfolanes, and disubstituted sulfolanes all undergo a characteristic cyclic decomposition reaction which is represented as follows: {A figure is presented} This fragmentation produces abundant ions when strong fragmentation-directing groups (-NH2, -OH, OMe, OEt) are present in the molecule, but assumes lesser importance when all of the substituents are weak directing groups (-H, -OAc, -Cl, -Br). The latter compounds fragment preferentially with elimination of the substituent. The most abundant ioins produced by 2-sulfolene and 3,4-epoxysulfolane are generated by deep-seated molecular rearrangements which are rationalized as follows: {A figure is presented}. © 1968.