Organic Chemistry. T
View Article Online / Journal Homepage / Table of Contents for this issue i. 369 Organic Chemistry. Nature of the Kolbe Electrochemical Synthesis of Hydrocarbons. FH. FICHTERand EDUARDKRUMMENAUHEH (Helvetica Chim. A cia, 1918, 1, 146-166).-The authors discuss the two theories put forward to explain the' mechanism of the Kolbe hydrocarbon synthesis, and draw the conclusion that the oxidation thsory is more in accord with fact than the theory based on the ionic hypothesis. It is shown that peroxides are produced by electrochemical oxidation, on platinum anodes, of solutions of saturated fatty acids and their salts. Since them peroxides may be produced by the action of hydrogen peroxide on aci6 anhydrides, it is to be assumed that the separation of the anhydride is the first step in the hydrocarbon synthesis. The anhydride is then anodic- ally oxidised, with the formation of a very unstable peroxide. The peroxide is then decomposed by the relatively high tempera- ture of the anode, with the formation of the hydrocarbon, thus: R*CO,Na + (RCO),-0 + 0 + (RCO),*O = 0 + R*R+ 2CO,, or a side reaction may also occur, thus: (R*CO),O=O 4 R-CO,*R + CO,. When th? peroxides are decomposed by heat, there is also a considerable amount of methane produced in addition to the expected hydrocarbon. These considerations are adapted to the formation and decom- position of organic peracids. Organic peracids m:by be prepared by the action of hydrogen peroxide on both acids and anhydrides, consequently the formation of these substances electrolytically on the, anode does not necessarily demand the intermediary formation Published on 01 January 1918.
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