Abstract
M.Sc. (Chemistry)
This study was directed towards the investigation of oxidations by dimethyldioxirane, a new
and versatile oxidant. To begin, the oxidation of various simple saturated hydrocarbons was
examined. These oxidations gave alcohols in yields that varied considerably. This
investigation showed that dimethyldioxirane reacts chemoselectively and that a preference is
shown for tertiary C-H bonds and even more so for tertiary cis C-H bonds in bicyclic
six-membered ring compounds and tertiary benzylic C-H bonds. A kinetic study of the
oxidations of benzylic C-H bonds of various cumene derivatives by dimethyldioxirane
confirmed the electrophilic nature of this reagent.
In order to investigate the chemoselectivity of oxidations by dimethyldioxirane, the oxidation
of eight steroids was examined. These oxidations were very selective and rarely gave more than
two products. In all but one case, the oxidations selectively produced alcohols in good yields.
The preference of dimethyldioxirane for tertiary cis C-H bonds in cyclic compounds and
tertiary benzylic C-H bonds was confirmed by the oxidation' of an estrone derivative and two
5,8-5teroids. In all three cases the anticipated compounds were obtained as the major products.
This oxidative method for the synthesis of 5,B-hydroxy steroids may provide a novel route for
the synthesis of cardioactive steroids.
The oxidation of a furo[2,3-b]benzofurane derivative was investigated to conclude this study of
oxidations by dimethyldioxirane. The succesful oxidation of this compound at C-3a would
furnish a synthon for aflatoxin M1 in a single step. Unfortunately, no product was obtained for
the oxidation of the furo[2,3-b]benzofurane derivative by dimethyldioxirane. Futher studies
into the source of this lack of reactivity are currently being undertaken.