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The synthesis of substituted non-symmetric tropones has proven to be a considerable synthetic challenge. Particularly, a 3,4,6-tnsubstituted tropone which is required for the total synthesis of CP-225,917 is currently being undertaken by our group. / Two approaches towards the synthesis of substituted tropones are presented. Both utilize linear diene precursors which are closed to 7-membered cycloheptene rings via ring closing metathesis. In the first method, linear precursors are synthesized by addition of nucleophilic substituents to carbonyl groups to form alcohol groups. After forming the cycloheptene ring, the alcohol groups are eliminated to form the tropone. The second method uses an oxidation protocol to form a,(3-unsaturation on either side of a cycloheptenone precursor. An attempt towards the synthesis of the desired tropone required for the CP-225,917 synthesis is also presented. / The methods described here use simple inexpensive starting materials and provide access to tropone substitution not readily available through other means.

This research is concerned with determining whether the previously reported synthesis of tropolone by the solvolysis of the dichloroketene-cyclopentadiene adduct in sodium acetate and acetic acid could be used to prepare 2-alkyltropones from the adducts of alkylhaloketenes and cyclopentadiene. The information obtained from these rearrangements could be useful in determining the mechanism of the ring expansion of halogenated ketene-cyclopentadiene adducts to tropone derivatives.

<p> New complexes formed between U(VI), Th(IV) and Sc(III) and tropolone have been prepared. These include the solvates UO2T2⋅X and ThT4⋅X (T = the tropolone anion; X =H2O and CH3OH), and the unsolvated chelate Sc3⋅. Some U(VI), Th(IV) and Sc(III) tropolonates reported in the literature have been re-examined and found to be incorrectly formulated.</p> <p> The adduct chelates UO2T2⋅HT, ScT3⋅HT and the previously unreported ThT4⋅HT have been prepared. Evidence has been presented for hydrogen-bonding in the additional monodentate tropolone ligand.</p> <p> The thermal conversion of the above solvates and adducts to yield UO2T2, ThT4 and ScT3 has been described.</p> <p> The ability of tropolone and other bidentate ligands to displace the water molecule in UO2T2⋅H2O and ThT4⋅H2O, and the addition of such ligands to ScT3, has been studied.</p> / Thesis / Master of Science (MSc)

Seventeen novel osmium cymene complexes with O,O′- and P,P′-chelating ligands as well as N- and P-monodentate ligands are reported. The osmium cymene complexes were synthesised and characterised by spectroscopic techniques (NMR, IR and Raman), elemental analysis, thermal analysis, conductivity studies and X-ray crystallography. The molecular structures of complexes 1(b), 2, 4, 6, 7(a)-(d) and 11 in this study are reported. The cymene rings of these complexes show different conformations due to loss of planarity influenced by the ancillary ligands as a result of ML back bonding. Osmium cymene complexes of the type [Os(η6-p-cymene)BrL2]+ (where L2 = chelating P,P′ ligand) and binuclear [{Os(η6-p-cymene)Br2}2 L2] (where L2 = bridging P,P′ ligand) were evaluated for anticancer activity against renal, melanoma, breast and HeLa cancer cells. The chelated-diphosphine osmium cymene complexes exhibited significant anticancer activities relative to the bridged-diphosphine osmium analogues. A series of O,O′-chelated osmium complexes exhibited moderate and poor anticancer activities. / Chemistry / M. Sc. (Chemistry)