Abstract
I. Carbohydrates form a major part of the highly fashionable "chiral pool", a natural and renewable source of optically pure materials that may find applications in synthesis. The development of a synthetic route (as seen in Figure 1) that would enable the largescale generation of highly functionalized optically pure cyclopropane (121) by exploitation of the inherent chirality observed in substrate (118) was examined.II. Electron poor alkenes such as dimethyl itaconate (125) were used as
precursors to synthesise gem-dibromocyclopropanes on a large scale in order
eventually to synthesise single enantiomers of cyclopropyl building blocks.
The monoacid (127) and diacid (129) were prepared from the cheap starting material (125) in moderate yield and their resolution by chiral amines was investigated. The resolution of diacid (129) was carried out successfully. Also a variety of reactions was carried out on these acids (as seen in Figure 2).
III. The dibromocyclopropanes (161) and (162) were prepared starting from an
electron poor alkene ethyl acrylate (157) to study enzymatic resolutions and other useful reactions (as seen in Figure 3).
The molecules (131), (161) and (162) are also useful precursors for further
development of polysubstituted cyclopropanes which are potentially valuable
precursors in synthesis of cyclopropane containing natural products.239 1,1,2,2-Tetrasubstituted cyclopropane (13n has been prepared in good yield by the reaction of ester (136) with methyllithium (as seen in Figure 5).
IV. 1-Chlorocyclobutene (172) and 1-chloro-1,2-dibromocyclobutane (173) were
prepared from the cheap precursor cyclopropanecarbaldehyde and some of their
reactions investigated. For example, [2+2]-cycloaddition reactions were examined with (172) and elimination reactions were examined with (173).
| Date of Award | 2006 |
|---|---|
| Original language | English |
| Awarding Institution |
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| Supervisor | Mark Baird (Supervisor) |