2-Substituted-1,3-butadienes are simple dienes generally prepared by elimination or rearrangement reactions under pyrolytic conditions, and are of interest as monomers for polymer synthesis. The most important of these dienes is 2-vinyl-1,3-butadiene ([3]dendralene), the simplest member of a group of acyclic and cyclic cross-conjugated polyolefins known as the dendralenes, which are suitable polyenes for multiple additions of the Diels-Alder type, used to produce large complex polycycles. The work in this thesis concentrates on the novel synthesis of four 2-substituted-1,3-butadienes by chelotropic extrusion reactions via SO<SUB>2</SUB> extrusion from sulpholenes (3-substituted tetrahydrothiophene-1,1-dioxides) and ethene extrusion from 1-substituted cyclohexenes. Such chelotropic extrusion reactions were performed using an efficient and selective technique known as Flash Vacuum Pyrolysis (FVP), which was used to prepare 2-cyanobutadiene via SO<SUB>2</SUB> extrusion and via ethene extrusion from the respective cyano-substituted sulfolene and cyclohexene derivatives, and 2-vinyl-1,3-butadiene and 2-ethynyl-1,3-butadiene by ethene extrusion. Additionally a novel compound 2-phenylethynyl-1,3-butadiene was prepared using both SO<SUB>2</SUB> extrusion from the respective sulfolene derivative and ethene extrusion from the respective cyclohexene derivative. The diene-transmissive nature of this novel compound together with the diene-transmissive nature of 2-cyano-1,3-butadiene was investigated by performing a number of Diels-Alder reactions with cyclic and acyclic dienophiles. Characterisation of all compounds by various analytical techniques including melting point analysis, mass spectroscopy, nuclear magnetic resonance and infrared spectroscopy is also discussed.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:657183 |
| Date | January 1993 |
| Creators | Maden, David N. |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/12540 |
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