No description available.

No description available.

This thesis describes the reaction of dimethylvimrlidene and vitylvitylidene carbenes with indene and dihydronaphthalene derivatives to give oyolopropanes. Rearrangement of these by acid or base catalysis lead to opening of the cyclopropane ring. The products formed depended on the site of attack of the acid or base on the molecule and an attempt was made to relate this to the structure of the cyolopropyl species. Indene, cyolopentadiene and fluorene anions were generated with sodium in liquid ammonia or by a phase transfer technique and reacted with allyl bromides to give alkyne substituted derivatives. Pyrolyeis of these derivatives at high temperatures in vacuo was carried out.

Two series of diene-conjugated diazo-compounds, a-diazoesters and a-diazophosphonate esters, were generated. In cases where the a,b and g,d-double bonds were aromatic in character both series decomposed to give fluorene derivatives. a-Diazoesters where the a,b-bond was olefinic and the g,d-bond was part of an aromatic ring gave 3-phenyl indenes as the sole product. The structures of these products were confirmed by the synthesis of authentic compounds. a-Diazophosphonate esters where the a,b-double bond was part of an aromatic ring and the g,d-bond was olefinic gave a moderate yield of <i>5H-</i>2,3-benzodiazepine and 2,-phenylindene. Triene-conjugated diazo-compounds with all <i>cis</i> stereochemistry where a cyclopentene ring was fused across the g,d-double bond, reacted <i>via</i> a [3+2]-cycloaddition reaction of unprecedented regioselectivity to give benzo[d]cyclopenta [1,2]diazocines. Where a cyclohexene ring was fused across the g,d-double bond the only isolated product was hexahydrocyclopropa [f]phenanthrene. Triene-conjugated diazo-compounds with a methyl and phenyl group on the g,d-double bond and possessing all <i>cis</i> stereochemistry reacted to give cyclopropa[a]napthalene as the major product and cyclopenta[a]phthalazine as the minor product. The cyclopenta[a]phthalazine was formed <i>via</i> a 1,1-cycloaddition of the diazo-compound with the g,d-double bond a reaction path unprecedented in such systems. Where the stereochemistry of the g,d-double bond is <i>trans</i> then the cyclopenta[a]phthalazine becomes the major product of the reaction with some of the cyclopropa[a]napthalene as the minor product.

No description available.

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.

No description available.

No description available.

No description available.

No description available.