Oxidation of hydrocarbons. 13. The oxidation of cinnamate ion by alkaline permanganate

Abstract

The rates of oxidation of cinnamate ion by permanganate have been compared under conditions where distinctly different products [Formula: see text] are obtained. Since the rates of both reactions respond in similar ways to substituent effects, deuterium substitution on the double bond, and to temperature changes, it may be concluded that the different products are due to post transition state reactions. Reaction sequences that are consistent with this conclusion and with the observed stoichiometries have been suggested.

Semiquantitative FMO Analysis of Substituent Effect on the Reaction of Permanganate Ion with Unsymmetrical Alkenes

“…Plots of log k 2 vs [(1 − d )(| C SL1 | + | C SL2 |) 2 + 2 d ]/| E RH − E SL | for the reactions of MnO 4 - with cinnamate ions; d = 0.93 (rate data from ref ).…”

“…Reaction of MnO 4 - with Cinnamate Ions in Alkaline Solution. We next applied eq 7 to the rate data for the reaction of permanganate ion with cinnamate ions in aqueous alkaline solution as elaborated by Lee and Nagarajan . The reaction is also nucleophilic since the Hammett plot follows a straight line of positive slope (Figure ).…”

“…It should be noted, however, that differences in size of the LUMO coefficient between the reaction sites of cinnamate ions (| C SL1 | and | C SL2 |) are more significant than those of methyl cinnamates (Table ).

9 Hammet plot for the reactions of MnO 4 - with cinnamate ions in alkaline solution (from ref ).

10 Plots of log k 2 vs [(1 − d )(| C SL1 | + | C SL2 |) 2 + 2 d ]/| E RH − E SL | for the reactions of MnO 4 - with cinnamate ions; d = 0.93 (rate data from ref ).

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Permanganate oxidation of unsaturated alcohols in alkaline media

“…As is known, permanganate ion is very reactive to unsaturated bonds both in aqueous acidic and alkaline media, and these reactions are considered to be some of the fastest reactions in organic chemistry. This can be stated in spite of the fact that the vast majority of rate constants measured for double bonds vary in a rather wide range, between the values 250 and 3000 dm 3 mol −1 s −1 1–9. For the acetylene bond somewhat lower values were measured 10–12.…”

Three Rate-Constant Kinetic Model for Permanganate Reactions Autocatalyzed by Colloidal Manganese Dioxide: The Oxidation ofl-Phenylalanine

“…One-electron redox processes have been favored over two-electron redox processes to initiate the reaction (eqs 14 and 15), because it is known that the permanganate oxidations of organic compounds in alkaline media yield Mn(VI). 78 This seems to suggest as a general rule that most of those reactions start with the reduction Mn(VII) → Mn(VI), and that lower oxidation states are formed from dismutation of Mn(VI) (eq 20) if the pH is low enough. The dismutation of Mn(VI) to yield Mn(VII) and Mn(V) (eq 20) has been assumed to involve hydrogenmanganate ion (HMnO 4…”