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Sialic acid has been sought as an excellent candidate for $\sp2$H NMR studies because of its ubiquitous presence at the penultimate non-reducing ends of membrane glycoproteins and glycolipids and because it has been associated with a number of biological and immunological phenomena. Regio- and stereoselectively deuteriated sialyl glycerolipids 1a, 1b and 1c were required for these studies and were synthesized.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE MAI) The first step of the synthetic route developed, involved the synthesis of unlabeled and labeled glycerolipids. The regio- and stereoselective deuterium incorporations in sialic acid and subsequent transformation of the deuteriated sialic acids into their respective glycosyl donors followed. The glycosylation of the glycerolipids with the appropriate glycosyl donors completed the synthesis of the model sialylglycerolipids and prompted further investigations of glycosidation methods for the synthesis of sialyl glycosides. A phase transfer catalysis procedure, particularly useful in the synthesis of thiosialosyl donors, was developed and the applicability of the procedure to produce a wide range of S- and O-sialosyl derivatives was explored. An extensive study of thioglycosylation reactions using a series of thiosialosyl donors, the glycerolipid and various thiophilic promoters resulted in the introduction of the concept of active and latent thiosialosyl donors which concluded the synthetic aspect of this research.

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A study was made of the various reactions which take place during the oxidation of an olefin by potassium permanganate. Though the experimental work reported here refers mainly to reactions conducted in aqueous media above pH7, the conclusions arrived at can be satisfactorily extended to explain the results obtained by other workers, under other reaction conditions. The oxidation was found to proceed under all reaction conditions by way of a cyclic ester intermediate (A). The route of the reaction is governed by the way in which the reaction conditions affect the decomposition of this intermediate. The following scheme demonstrates the kinds of reactions which have been shown to be involved.* (A) Obtained in 50--100% at 0--10° in aqueous media above pH12, and in 0--60% yield in mixed solvents. (B) Obtained in 80--90% yield using a 1--5 molar excess of permanganate and a olefin concentration of 0.1%; obtained in 25% yield using a 30-fold excess of permanganate. (C) Obtained in 20% yield using an olefin concentration of 0.5% and a 30-fold excess of permanganate. (D) Obtained in 10--20% yield in aqueous media in the pH region 7--10, using an olefin concentration of 0.5% and a 30-fold excess of permanganate; obtained in 0--50% yield in mixed solvents; obtained in 50--100% yield in non-aqueous media. The formation of the intermediate pi-complex and the hydroxyl ion-catalyzed rearrangement of this complex to the cyclic intermediate (A) were demonstrated by the results of a kinetic study of the reaction of permanganate with oleate ion. The order with respect to the permanganate and olefin concentrations was unity, whereas a complex order with respect to the hydroxyl ion concentration was observed. A number of different kinds of oxyanions, such as borate, tellurate and periodate, also appear to form pi-complexes with an olefin, since the addition of one of these oxyanions to the permanganate-olefin reaction mixture resulted in a kinetic competition for the olefin between permanganate and the added oxyanion. It was possible to calculate the equilibrium constant of an olefin-oxyanion complex by a suitable interpretation of the effect of the added oxyanion on the olefin-permanganate reaction. Thus a novel procedure can be developed for the study of certain kinds of pi-complexes. (Abstract shortened by UMI.) *Please refer to dissertation for diagrams.

The rates of the alkaline hydrolysis of some esters and amides, and of the alkaline fading of certain organic dyes, have been studied over a range of hydrostatic pressures from atmospheric pressure to 16,000 pounds per square inch. In the case of the ester and amide hydrolyses the results obey van 't Hoff's law, the logarithm of the rate constant varying linearly with the pressure. From the slopes of the lines values of DeltaV*, the volume of activation, were calculated; they fell in the range of -10 to -17 cc, per mole. These negative volumes of activation are to be correlated with the negative entropies of activation for the reactions. It is suggested that the results maybe explained in terms of the hypothesis that the activated complex is much more polar than the reactants. In the case of the alkaline fading of dyes the results were somewhat more complicated, the van 't Hoff law not always being obeyed. In the case of crystal violet the rate was found to be independent of the pressure. With brom phenol blue and phenol phthalein the rates were markedly increased by pressure, so that the volumes of activation are negative. These negative volumes of activation are found to be correlated with the entropies of activation for the reactions. An explanation for the results is given in terms of the changes in polarity during the course of the reactions.

High throughput methods are valuable for decreasing the time needed for the development of new asymmetric reactions. Catalyst discovery may be accelerated by the rapid screening of reactions for enantioselectivity. Chiral substrates are used in a novel fluorescence resonance energy transfer (FRET) assay. A fluorophore (donor), a fluorescence quencher (acceptor) and a recognition element are part of the assay substrates. The latter are prepared using different fluorescent donor/acceptor pairs for each enantiomer of the recognition element. Screening is performed using equimolar mixture of the two substrates. Weak fluorescence indicates no reaction. Strong fluorescence at both wavelengths indicates a non-selective reaction while an enantioselective coupling would display strong fluorescence at only one wavelength.* *Please refer to dissertation for diagrams.

Les deux minéraux argileux, la montmorillonite-sodium et l'hectorite-sodium d'une part, et la magadiite d'autre part sont des phyllosilicates respectivement de la famille des smectites et des polysilicates lamellaires qui présentent la propriété de pouvoir échanger les cations sodiums, situés dans leur espace interlamellaires avec les protons pour former leur acide correspondant par le traitement à l'HCl. L'utilisation de la méthode de déconvolution pour les spectres de la RMN du 29Si MAS de la montmorillonite et l'hectorite a pour but d'identifier les différents environnements du silicium en fonction de la concentration de l'acide utilisé. Le greffage covalent des molécules organosilane (3-Chloropropyltrimethoxysilane, 3-Mercaptopropyltrimethoxysilane et N-[3-(trimethoxysilane) propyl] éthylènediamine) sur les groupements silanols de la région interlamellaire de la forme protonée des phyllosilicates menant à la formation de nouveaux matériaux, a été réalisé. Le 1, 8-octanediol a été condensé sur les groupements silanols de la magadiite. Les ions sodiums ont d'abord été échangés par des ions dodecyltrimethylammonium avant de procéder au greffage covalent du diol sur les sites hydroxyles de l'entrecouche. Les différents matériaux obtenus ont été caractérisés par diffraction des rayons X (DRX), par spectroscopie infrarouge (IR), par analyse themogravimétrique (ATG) et par résonance magnétique nucléaire (RMN 29Si et RMN 13C).

Le développement d'une stratégie qui permet d'installer un groupement méthyle sélectivement en position C8 d'une trans décaline est décrit. La réaction en tandem oxy-Cope/ene/Claisen avec un groupement directeur dans le précurseur, tel un sulfure d'éthyle, permet de n'obtenir qu'un seul diastéréoisomère (Schéma i).* Cette méthodologie a permis de synthétiser l'analogue sans le gem-diméthyle en C4 du produit naturel ambliol B (Schema u).* Cette méthodologie a aussi permis le deéeloppement de la synthèse d'un analogue d'agelasimine A, soit (+/-)-desdimethylagelasimine A. Cette étude s'est terminée à quelques étapes de la fin. Les défis majeurs de cette synthèse étant résolus, l'accomplissement de cette dernière constitue une formalité (Schéma iii).* *Please refer to dissertation for diagrams.