Chapter I contains a brief introduction to the applications of dioxirane chemistry and outlines the
mechanistic investigations carried out to date.
Chapter 2 describes investigations into the dimethyldioxirane oxidation of para-substituted
N,N-dimethylanilines in acetone. The N-oxides were found to be the only products. Relative rates
were determined and compared with those of reactions with methyl iodide and other oxidants. The
dimethyldioxirane reactions followed the Hammett relationship with a p value of -1.0. The reaction
rates are strongly accelerated in the presence of water and the overall reaction mechanism is
electrophilic in nature and does not involve free radical species or electron transfer.
Chapter 3 looks at the regioselectivity of dimethyldioxirane when used to oxidise several
polyfunctionalised nitrogenous drugs with a view to developing a system for use in oxidative
The regioselectivity of dimethyldioxirane in the oxidation of polyhydroxy steroids, namely a series
of bile acid methyl esters, is discussed in chapter 4. No evidence for preferential oxidation of axial
over equatorial hydroxyls or vice versa was seen. Instead the least hindered hydroxyl at C3 was
oxidised preferentially with some oxidation also occurring at C6 and C7. Hydroxyls at the sterically
hindered C 12 were not oxidised. This provides further evidence for the proposed butterfly transition
Finally, chapter 5 discusses the use of novel trifluoromethyl aryl ketones as promoters for Oxone®mediated
epoxidations. 4-(trifluoroacetyl)benzoic acid was used succesfully and can be readily
isolated for re-use by simple base extraction.
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University