Skeletal Rearrangements of 9-Thiabicyclononanes and Related Syntheses

Livingston, Catherine Mary (1976) Skeletal Rearrangements of 9-Thiabicyclononanes and Related Syntheses. PhD thesis, University of Glasgow.

Abstract

This thesis descibes two related areas of chemical investigation. In the first section pyrolytic and base-induced eliminations of 2,6-disubstituted 9-thiabicyclo[3.3.1] nonanes and 2-substituted 9-thiabicyclo [3.3.1]non-6-enes are found to occur with skeletal rearrangement. Similar rearrangement has not been observed when substituents in these positions undergo nucleophilic replacement even though assistance by the lone pairs of electrons on the bridging sulphur atom has been proposed. The rearrangement accompanying elimination is rationalised in terms of the structural and stereochemical characteristics of these compounds. In the particular case of O-alkyl dimethyl thiocarbamate pyrolysis the expected cis elimination, yielding an alkene, is not observed. Instead a side-chain rearrangement to an S-alkyl dimethyl thiocarbamate occurs which has previously been observed only for aromatic thiocarbamates. This rearrangement in an aliphatic situation could arise by a concerted process involving the skeletal carbon-sulphur bonds and a mechanism is proposed. The second section describes three synthetic approaches to 1,2- and 1,4-cyclooctatetraenoquinones, which are potentially pseudo-aromatic. The first method is an extention of earlier attempts to obtain the 1,2-quinone from monocyclic intermediates with protected carbonyl groups. The second and third approaches employ sulphur-bridged bicyclic compounds as synthetic intermediates to the 1,4-quinone. Appropriate functionalisation of these stable systems followed by extrusion of sulphur was proposed in order to overcome the transannular cyclisation which frustrated monocyclic routes.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Organic chemistry
• Date of Award: 1976
• Depositing User: Enlighten Team
• Unique ID: glathesis:1976-78720
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 30 Jan 2020 14:59
• Last Modified: 30 Jan 2020 14:59
• URI: https://theses.gla.ac.uk/id/eprint/78720