Some Studies in the Synthesis of Medium Ring Ketones

Hamilton, James Graham (1961) Some Studies in the Synthesis of Medium Ring Ketones. MSc(R) thesis, University of Glasgow.

Abstract

Synthetic routes to 9 and 10 membered ring systems have been investigated as follows: Biroh reduction of napalene yields isotetralin (1:4:5:8 tetrahydronaph halene) which has been converted through its mono epoxide (9:10-oxido: Delta2:6 hexahydronaplthalene) to trans Delta 2:6 hexahydronaphalene-9:10-diol and this substance has been cleaved by means of lead tetrancetate to cyclodeca-3:8 dien-1:6-dione. The product has been characterised as its bis-2:4-dinotrophenylhydrazone. Attempts to introduce further unsaturation into the ring were unsuccessful. A similar series of reactions was carried out on indane, and yielded in turn, 4:7-dihydro-8:9 oxidoindene, the corresponding diol, Delta5:6 hexa-hydroindene-8:9-diol and cyclonon-7en-1:5-dione. The structure of this end product was rigorously established by its reduction under special conditions to cyolononan-1:5-diol. This product was isolated as a mixture of stereoisomers, one of which was found to be identical with an authentic sample kindly supplied by Professor V. Prolog of Zurich. Under different conditions the reduction proceeded anomalously. In an attempt to isomerise the double bond into conjugation with one of the carbonyl functions, the ene dione was treated with ethanolic potassium acetate. The product was not the expected conjugated dione. An exhaustive investigation, employing both chemical and spectroscopic methods has shown that the potassium acetate treatment promotes a transannular aldol condensation yielding initially 4:5:6:7-tetrahydroinden-7-one which dimerises fairly rapidly. The structure of the dimer has been tentatively assigned on the basis of its proton magnetic resonance spectrum.

• Item Type: Thesis (MSc(R))
• Qualification Level: Masters
• Keywords: Organic chemistry
• Date of Award: 1961
• Depositing User: Enlighten Team
• Unique ID: glathesis:1961-79411
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 05 Mar 2020 10:02
• Last Modified: 05 Mar 2020 10:02
• URI: https://theses.gla.ac.uk/id/eprint/79411