Trimethylethylene oxidation

Among the many alkyl-substituted epoxides that have hi n reported to undergo hydration under various conditions are propylnm oxide, isobutylene oxide, 1,2-epoxybutone, trimethylethylene oxide, and others-. . . , jtf, i w. . shown in JSq, (50 ). 

Photo-oxidation of trimethylethylene was frequently used as evidence to support or contradict various mechanistic possibilities for the ene reaction. For example, the equal amounts of photo-oxidized products (olefin 4) led to the conclusion that the ene reaction proceeds without any regioselectivity (Scheme 5). 

Trimethylethylene dibromide has been obtained by adding bromine to trimethylethylene and to tertiary amyl alcohol. Methyl iso-propyl ketone has been prepared by heating trimethylethylene glycol (2-methyl-2,3-dihydroxybutane) with dilute hydrochloric acid, by heating trimethylethylene chloro-hydrin (2-methyl-2-hydroxy-3-chlorobutane) in a sealed tube with water, by boiling trimethylethylene dibromide with lead oxide (PbO) and water, by heating trimethylethylene dibromide with water, by the action of iso-propylmagnesium bromide on acetic anhydride, and by a variety of other methods not particularly related to the one here described. ... 

Liquid phase oxidation with potassium permanganate shows a similar trend in the reactivity. The importance of the groups attached to the unsaturated carbon atoms is further shown by experiments on the action of potassium permanganate on more complex olefins.2, The results have shown pentene, cyclohexene, and trimethylethylene are fairly easily oxidized but that diisobutylene and diamylene are surprisingly stable. 

Higher Olefins. Yapor-phase oxidation of olefins in the presence of vanadium pentoxide catalysts results in substantial yields of maleic anhydride which increase with increase in molecular weight of the olefin. Thus, from pentene-2, trimethylethylene, technical amylene, methyl pen-tene, heptene, and octene, approximate relative conversions of 10, 25, 27, and 30 per cent, respectively, were obtained from 5, 6, 7, and 8 C-atom olefins. Optimum tanperatures of about 425 C were foimd for amylene oxidation. Catalysts used for 250 hr showed no reduction in activity. 

By the action of zinc ethyl on allyl iodide he obtained impure propyl ethylene (C H C H ), an isomer of amylene. (Commercial amylene is a mixture, the chief constituent being trimethylethylene, (CHs)2C CH-CHs). Frankland, in Liebig s laboratory, by heating allyl iodide with zinc obtained amylene and what he described as amyl, ready diamyl or tetramethylhexane, which Wurtz obtained from amyl iodide and sodium it is (CHj)2C,Hxo(CH8)j. Wurtz also obtained new isomers of amyl alcohol, the true constitution of which was established only later. Bauer obtained triamylene (C15H30) as well as di- and tetramylene. He also obtained amylene oxide, corresponding with ethylene oxide. 

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