Aspects of the Synthesis of Polycyclic Thianes and Related Systems

Routledge, William (1978) Aspects of the Synthesis of Polycyclic Thianes and Related Systems. PhD thesis, University of Glasgow.

Abstract

The acid-catalysed acetylation of bicyclo [3.3.1] nonan-2,6-dione (79) and its 9-thia and 9-oxa analogues (165 and 187) is described. In the presence of toluene-p-sulphonic acid or low concentrations of concentrated sulphuric acid, O-acetylation occurred to produce mixtures of the corresponding mono- and bisenol acetates. At higher sulphuric acid levels, C-acetylation was favoured, 79 and 165 producing adamantane and 2-thiaadamantane derivatives respectively while 187 yielded the doubly C-acetylated species (202). The attempted dehydrochlorination of 2,6-dichloro-9-thiabicyclo-[3.3.1] nonane (161) with pyridine failed to produce an olefinic product but yielded instead the bispyridinium salt (215). Reaction of chloroalkene (213) with pyridine at room temperature gave monopyridinium salt (216) which underwent facile structural rearrangement at elevated temperatures (>50) to give a mixture of 216 and 225. Pyrolytic elimination of pyridine hydrochloride from 215 and 216 proceeded with structural rearrangement furnishing 9-thiabicyclo [4.2.1] nona-2,4-diene (229). In order to prepare 8-thiabicyclo [3.2.1] octane derivatives as potential precursors to thia- analogues of biologically active tropane alkaloids, the condensation of sulphur dichloride with cycloheptadienes (238, 282, 286 and 292) was investigated. Cyclohepta-2,6-dienone (238) and its ethylene ketal (292) reacted with SCI2 in an identical regiospecific manner to produce the unsymmetrical 1:1 adducts (307 and 305) while 1-benzoyloxycyclo-hepta-3,5-diene (286) gave the expected symmetrical dichloride (295) Cyclohepta-3,5-dienone (282) reacted with SCl2 with the elimination one equivalent of hydrogen chloride furnishing the photosensitive allylic chloride (301) which was further dehydrochlorinated to 8-thiabicyclo [3.2.1]octa-3,6-dien-2-one (303).

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Organic chemistry
• Date of Award: 1978
• Depositing User: Enlighten Team
• Unique ID: glathesis:1978-78792
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 30 Jan 2020 14:54
• Last Modified: 30 Jan 2020 14:54
• URI: https://theses.gla.ac.uk/id/eprint/78792