92688-78-3Relevant articles and documents
Fragmentation Patterns in the Gas-Phase Pyrolysis of Some Bi- and Tri-cyclic Sulfolanes Related to the 8-Thiabicyclonon-3-ene 8,8-Dioxide Ring System
Aitken, R. Alan,Cadogen, J. I. G.,Gosney, Ian,Newlands, Stephen
, p. 2301 - 2308 (2007/10/02)
Depending upon the degree of ring strain, the thermal breakdown of cis-8-thiabicyclonon-3-ene 8,8-dioxide 5 and related ring systems in the gas phase follows widely differing pathways.Decomposition of 5 occurs only under forcing conditions, resulting in complete fragmentation of the sulfolane ring to give a benzene and toluene, while pyrolysis of the 2,5-bridged analogues 6-8 proceeds by a retro-Diels-Alder reaction at much lower temperatures to give 1,3-dienes and the decomposition products of 3-sulfolene, buta-1,3-diene and SO2.Epoxidation of the double bond in the compounds results in a marked change in their thermal fragmentation behaviour; only SO2 is lost to produce novel divinyl epoxides.The corresponding N-ethoxycarbonylaziridines, formed by photolysis of the unsaturated sulfones in ethyl azidoformate, undergo extensive decomposition on pyrolysis and do not yield any useful products.The saturated sulfone 28 gives an expected octa-1,7-diene upon flash vacuum pyrolysis (FVP), but only under relatively severe conditions.Three isomeric diene sulfones 30-32 have also been examined and show a varied pattern of reactivity under FVP conditions.
