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.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/10643 |
| Date | January 1957 |
| Creators | Wolfe, Saul. |
| Publisher | University of Ottawa (Canada) |
| Source Sets | Université d’Ottawa |
| Detected Language | English |
| Type | Thesis |
| Format | 290 p. |
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