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Many known synthetic methods enable the hydrolysis of alkynes with Markovnikov regioselectivity. In contrast, the synthetic chemist’s toolbox lacks broadly effective processes for the hydrolysis of alkynes with anti-Markovnikov regioselectivity. This thesis describes the development of new synthetic method that will help address this deficiency. This document begins with a review of the concepts of Markovnikov and anti-Markovnikov regioselectivity and an explanation of the broad extension of this terminology that is applied throughout the remainder of this thesis to encompass all alkyne substrates. Next, a review of the published methods of alkyne hydrolysis is presented, with emphasis on the internal alkyne substrates. The remainder, and bulk, of this thesis details the development of a new synthetic methodology that leverages regioselective radical thiolation chemistry to achieve anti-Markovnikov hydrolysis of alkynes. Internal alkynes are first converted to oxathiolanes or vinyl sulfides with anti-Markovnikov regioselectivity followed by hydrolysis of these moieties to the corresponding anti-Markovnikov ketones. In the case of aryl-alkyl alkyne substrates, complete anti-Markovnikov selectivity is demonstrated with a broad range of examples. Aryl-aryl alkyne substrates offer a mixture of regioisomers favoring anti-Markovnikov products. Finally, the utility of this methodology is demonstrated with its application to the successful first total synthesis of the bioactive natural product isomeranzin. / Thesis / Master of Science (MSc)

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<p> An investigation of flabelliformine, an alkaloid obtained from Lycopodium flabelliforme, led to the establishment of its structure. </p> <p> A study of the mass spectra of annotine (a minor alkaloid present in Lycopodium annotinum) and several of its derivatives in combination with degradative work gave support to a total structure proposed previously for the alkaloid.</p> <p> A synthetic approach to the Lycopodium alkaloids was considered. 1-Carbomethoxy-3-methyl-7-methoxybicyclo [3.3.1] non-3-en-9-one, a compound which appeared suitable as an intermediate in the synthesis, was prepared in low yield. The difficulty encountered in the purification of this compound, coupled with the low yield in which it was obtained, indicated the impracticality of this approach to a total synthesis of a Lycopodium alkaloid.</p> / Thesis / Doctor of Philosophy (PhD)

<p> N-[(9-β-D-ribofuranosyl-9H-purin-6-yl)carbamoyl]- threonine, a hypermodified nucleoside found in transfer RNA represents the archetype structure of a group of synthetic ureidopurines which promote cell division in plants. L-threonine was shown to be incorporated into this nucleoside in Tobacco tissue and Rhizopogon roseolus transfer RNA. Also, this nucleoside was isolated as a free molecule in Rhizopogon roseolus growth medium.</p> <p> Chromatographic analysis of an enzymic hydrolysate of 3 g of yeast transfer RNA failed to indicate the presence of a lipophilic derivative of PCT riboside. It is concluded that PCT riboside occurs in transfer RNA with a free carboxyl group.</p> / Thesis / Master of Science (MSc)

<p> Approximately 80 percent of all synthetic polymers used are cross-linked polymers, unfortunately the characterization of cross-linked polymers has not kept up with their use. This study tries to help in the characterization of cross-linked polymer systems. More specifically the interactions of cross-linked polymer systems with solvents will be probed. Nuclear Magnetic Resonance (NMR) spectrometric techniques will be used to characterize solvent-polymer interactions.</p> <p> The cross-linked polymer system studied was the polymer ethylene glycol dimethacrylate (EGDMA) with methylmethacrylate (MMA). A splitting of the solvent signals was observed in the NMR spectrum which can be used to understand these solvent-polymer interactions. Several NMR parameters and swelling of the polymers were measured in order to understand these interactions. The chemical shift differences between the solvent types and the peak linewidths were measured. As the polymer becomes more highly cross-linked the chemical shift differences and the linewidths increases. This compactness can be monitored by measuring the degree of swelling of the polymer. In addition the possibility of an isotope effect was explored by monitored by placing the polymer in solvent mixture of CHCl3/JCDCl3 and varying the temperature. No isotope dependence was found to exist for chloroform over the temperature range analyzed. The degree of splitting and the occurrence of splitting was found to be dependent on the solvent system. In general, solvent splitting is present for solvents that are able to cause the polymer to swell appreciably. For 4.8 weight percent EGDMA in EGDMA/MMA polymer a splitting is usually observed for a solvent that is able to swell the polymer to twice its dry size. The association between the solvents and the polymers can be best explained by breaking the interactions into a number of components.</p> <p> The explanation is based on the presence of three interactions. A weak chemical interaction exists between the solvent and the polymer to account for the field dependent linewidths. A second chemical interaction that results is a binding between the solvent and the polymer and causes the solvent splitting to occur. The third interaction is a result of the increased rigidity and compactness of the polymer as the weight percent EGDMA in EGDMA/MMA polymer increases. Alternatively as the polymer becomes more compact the chemical shift difference between the two types of solvents increases.</p> <p> Ultimately, it is shown that NMR is a useful aid in understanding solvent-polymer interactions.</p> / Thesis / Master of Science (MSc)

<p> This thesis presents a study of the compatiblization of a hydrophobic, synthetic polymer, polydimethylsiloxane (PDMS) and a hydrophilic biopolymer, starch. The Diels- Alder adduct of cyclopentadiene and maleic anhydride, bicyclo[2.2.1]hept-5-ene-2,3- dicarboxylic-anhydride, (1), was hydrosilylated with hydride- terminated PDMS to yield α,ω-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic-anhydride-polydimethylsiloxane, (4) having an average molecular weight of 750 g mol^-1. This was then reacted with starch using dimethylaminopyridine as a catalyst in a dimethylsulfoxide medium at 80°C to yield a silicone-starch graft copolymer having a γ-carboxylic-ester linkage.</p> <p> In order to study the influences of the quantity of hydrophobic and hydrophilic components, a series of composites were synthesized varying the starch and silicone stoichiometry (series-1).</p> <p> In order to study the influence of the molecular weight of the silicone, 4 was redistributed with octamethylcyclotetrasiloxane (D4) via cationic polymerization to yield higher molecular weight derivatives. The products were 7 (1500 g mol^-1) and 8 (9000 g mol^-1). These were reacted with starch to give a series of composites for each molecular weight of the functionalized silicone.</p> <p> Spectroscopic and physical properties were analyzed for developing trends.</p> / Thesis / Master of Science (MSc)

<p> It is well known that complex coacervates can be prepared by combining aqueous solutions of oppositely charged biopolymers, such as gelatin and gum arabic. There are few examples of synthetic polyelectrolytes that produce complex coacervates, however. Two series of anionic copolymers capable of forming complex coacervates with branched polyethylenimine (PEI) in water have been prepared. One series consists of binary copolymers containing methacrylic acid (MAA) and poly(ethylene glycol) monomethyl ether monomethacrylate (PEGMA) in molar ratios ranging from 20:80 to 80:20, as well as the two homopolymers, poly(MAA) and poly(PEGMA). Another series contains an equimolar amount of MAA and PEGMA, together with between one and ten percent of a third, hydrophobic monomer, butyl methacrylate (BMA).</p> <p> Both binary and ternary copolymers show lower critical solution temperatures, LCST's, ranging from 60.8°C to 1.5°C depending on composition. Furthermore, complex coacervation occurs upon addition of aqueous PEI to aqueous solutions of these copolymers. The percent volume of the liquid coacervate phase is independent of copolymer composition. However, with increasing MAA to PEGMA ratio in the binary copolymer, the concentration of the coacervate increases, reflecting an increased coacervation efficiency. The coacervate composition was not significantly affected by the BMA in the ternary copolymer series.</p> / Thesis / Master of Science (MSc)