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The osmium-mediated aminohydroxylation reaction is a powerful oxidation that introduces a hydroxyl group and a protected amino group in a syn relationship across an olefinic double bond. This study concerns one approach to controlling the regioselectivity of this oxidation. Introduction I The mechanism, scope and limitations of the aminohydroxylation reaction are discussed, with particular attention to the asymmetric version, providing a background from which the newly developed methodology has emerged. Results and Discussion I Development of the reaction This section concerns the original attempts to perform the tethered aminohydroxylation reaction, and early process optimisation to maximise the yield of aminohydroxylated product produced. Scope of the reaction This section details the results of the TA reaction as applied to further allylic carbamates demonstrating the applicability of the reaction to other olefinic geometries. The diastereoselectivity of the reaction in cyclic and acyclic systems is reported, and a model to explain the observed results discussed. Also covered within are the syntheses of the various substrates and proof of the stereochemistry of the products. Mechanistic investigations Work involving attempts to isolate a catalytic intermediate from the reaction is described. A crystal structure of this intermediate is discussed. Introduction II The isolation and physiological properties of the antibiotic compound hygromycin A are described. Prior synthetic routes towards this compound are discussed. Results and Discussion II Three approaches towards the aminocyclitol unit of hygromycin A, employing the tethered aminohydroxylation reaction, are outlined. Two of these allow for potential future development and completion of the synthesis.

A range of substituted l,3-dithiol-2-ylidene systems have been prepared. These species have, subsequently, been converted to nitroso derivatives. The role of the 4-, 5- and ylidene subtituents in stabilising the nitroso-alkene moiety thus obtained has been investigated. X-ray molecular crystal data which show that these species are stabilised by intramolecular interactions are presented. Conversion of the nitroso derivatives to their thionitroso analogues has been attempted, but was unsuccessful. A selection of l-(l,3-dithiol-2-ylidene)-prop-2-ene systems have been prepared. These systems have been shown to be sufficiently activated to undergo nitrosation reactions at the 3-vinyl positon, though the nitroso-alkenes thus formed are unstable. A new route to 4,5-dicarbomethoxy-2-(tributylphosphino)-l,3-diselenolium tetrafluoroborate utilising hydrogen selenide as the source of selenium has been detailed. This Wittig reagent has been employed in the synthesis of various 1,3-diselenol-ylidene systems. Conversion to nitroso derivatives has been accomplised and X-ray data shows that the resultant nitroso-alkenes are stabilised by an intramolecular oxygen—selenium interaction.

Thesis (Ph. D.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 85-91). Also available on the World Wide Web.

Thesis (Ph. D.)--Michigan State University. Dept. of Chemistry, 2006. / Title from PDF t.p. (viewed on Nov. 17, 2008) Includes bibliographical references (p. 344-349). Also issued in print.

Thesis (Ph. D.)--Columbia University, 1934. / Vita. Bibliography: p. 28-30.

Thesis (Ph. D.)--University of Hong Kong, 1998. / Includes bibliographical references (leaves 220-234).

Thesis (Ph. D.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 175-187).

Thesis (Ph. D.)--Brigham Young University. Dept. of Chemistry and Biochemistry, 2007. / Includes bibliographical references.