2.2.4- trimethylpentane, oxidation

The products for which the cyclo-C4 isomerization intermediate has been suggested, can also be explained by a sequence of vinyl insertions. Thus, two vinyl insertions would be adequate to explain the formation of m-xylene from 2,3,4-trimethylpentane. Although we have seen in previous sections that extensive reaction sequences are possible on platinum, isomerization by a single vinyl insertion process on chromium oxide is relatively difficult, and the chance of two occurring in sequence would therefore be expected to be very low. In fact, the proportion of m-xylene is comparable to that of o- and p-xylene. 

Products identified from the reaction of 2,2,4-trimethylpentane with OH radicals in the presence of nitric oxide included acetone, 2-methypropanal, 4-hydroxy-4-methyl-2-pentanone, and hydroxy nitrates (Tuazon et al., 2002). 

Indenopyrene, see Indeno[l,2,3-crf pyrene l//-Indole, see Indole Indolene, see Indoline Inexit, see Lindane Inhibisol, see 1,1,1-Trichloroethane Insecticide 497, see Dieldrin Insecticide 4049, see Malathion Insectophene, see a-Endosulfan, p-Endosulfan Intox 8, see Chlordane Inverton 245, see 2,4,5-T lodomethane, see Methyl iodide IP, see Indeno[l,2,3-crf pyrene IP3, see Isoamyl alcohol Ipaner, see 2,4-D IPE, see Isopropyl ether IPH, see Phenol Ipersan, see Trifluralin Iphanon, see Camphor Isceon 11, see Trichlorofluoromethane Isceon 122, see Dichlorodifluoromethane Iscobrome, see Methyl bromide Iscobrome D, see Ethylene dibromide Isoacetophorone, see Isophorone a-Isoamylene, see 3-Methyl-l-butene Isoamyl ethanoate, see Isoamyl acetate Isoamylhydride, see 2-Methylbutane Isoamylol, see Isoamyl alcohol Isobac, see 2,4-Dichlorophenol Isobenzofuran-l,3-dione, see Phthalic anhydride 1,3-Isobenzofurandione, see Phthalic anhydride IsoBuAc, see Isobutyl acetate IsoBuBz, see Isobutylbenzene Isobutane, see 2-Methylpropane Isobutanol, see Isobutyl alcohol Isobutene, see 2-Methylpropene Isobutenyl methyl ketone, see Mesityl oxide Isobutyl carbinol, see Isoamyl alcohol Isobutylene, see 2-Methylpropene Isobutylethylene, see 4-Methyl-l-pentene Isobutyl ketone, see Diisobutyl ketone Isobutyl methyl ketone, see 4-Methyl-2-pentanone Isobutyltrimethylmethane, see 2,2,4-Trimethylpentane Isocumene, see Propylbenzene Isocyanatomethane, see Methyl isocyanate Isocyanic acid, methyl ester, see Methyl isocyanate Isocyanic acid, methylphenylene ester, see 2,4-Toluene-diisocyanate... 

ALDEHYDES BY OXIDATION OF TERMINAL OLEFINS WITH CHROMYL CHLORIDE 2,4,4-TRIMETHYLPENTANAL... 

Aliphatic hydroxylation. As well as unsaturated aliphatic compounds such as vinyl chloride mentioned above, which are metabolized by epoxidation, saturated aliphatic compounds also undergo oxidation. The initial products will be primary and secondary alcohols. For example, the solvent n-hexane is known to be metabolized to the secondary alcohol hexan-2-ol and then further to hexane-2,5-dione (Fig. 4.9) in occupationally exposed humans. The latter metabolite is believed to be responsible for the neuropathy caused by the solvent. Other toxicologically important examples are the nephrotoxic petrol constituents, 2,2,4- and 2,3,4-trimethylpentane, which are hydroxylated to... 

Studies with sulfated zirconia also show similar fast catalyst deactivation in the alkylation of isobutane with butenes. It was found, however, that original activities were easily restored by thermal treatment under air without the loss of selectivity to trimethylpentanes. Promoting metals such as Fe, Mn, and Pt did not have a marked effect on the reaction.362,363 Heteropoly acids supported on various oxides have the same characteristics as sulfated zirconia.364 Wells-Dawson heteropoly acids supported on silica show high selectivity for the formation of trimethylpentanes and can be regenerated with 03 at low temperature (125°C).365... 

Figure D2.1.1 UV absorbance of sunflower oil samples dissolved in 2,2,4-trimethylpentane. An unoxidized sample (dashed line) and an oxidized sample (solid line) showing the characteristic absorbance peak for conjugated dienes (CDs) at 233 nm as well as peaks at 268 and 278 nm corresponding to conjugated trienes (CTs). The plot in the upper right corner shows an enlarged view of the absorbance curve in this region.

Scheme 11.27 Hydrogenation products of dibenz[a,/j]anthracene over platinum oxide in 1 1 mixture of 2,2,4-trimethylpentane and acetic acid at room temperature and atmospheric pressure.

Pentane. The systems n-pentane-NOa, and 2,3,4-trimethylpentane-NOa, were studied in the presence and absence of carbon monoxide. In both systems 2,000 ppm CO added to 10 ppm paraffin and 3 ppm NO, increased the oxidation rate of NO but did not affect the reactivity of the paraffin. The increase in the oxidation rate of NO was the same as that shown in Figure 1 for 2,000 ppm CO and 4.6 ppm NO, in the absence of hydrocarbon ozone was not formed in either system. 

Whereas extensive oxidation of n-heptane occurred from about 550 K (Fig. 6.1), the oxidation of 2,2,4-trimethylpentane became prominent only above 750 K (Fig. 6.2) under the conditions of these experiments. The extents of reaction that occurred below 750 K were limited by the residence time in the reactor. The considerable difference of reactivity of these two alkanes, may be expected to arise from the relative difficulty for 2,2,4-trimethylpentylperoxy radicals to undergo isomerization reactions compared with the reactivity of n-heptylperoxy radicals (Chapters 1 and 2). Related arguments are presented at the end of this chapter. Although the temperature range within which the ntc of reaction rate was observed in... 

The oxidation of some aliphatic amines is a good route to aliphatic nitro compounds. tert-Butylamine is oxidized in 83% yield to 2-methyl-2-nitropropane by potassium permanganate in water at 45 °C for 8 h and at 55 °C for 8 h [738, 892], Under similar conditions, 4-amino-2,2,4-tri-methylpentane is converted into 4-nitro-2,2,4-trimethylpentane in 69-82% yields [859]. Refluxing 3a-acetoxy-20a-amino-5p-pregnane with a chloroform solution of m-chloroperoxybenzoic acid for 40 min furnishes 3a-acetoxy-20a-nitro-5p-pregnane in 66% yield [379]. 2-Aminobutane is converted into 2-nitrobutane by peroxyacetic acid [253] or dimeth yldioxirane [277] (equation 498). 

Monocrotaline (45) was reduced (LiAlH4) to 2,3,4-trimethylpentane-l,2,3,5-tetraol (46). Periodate oxidation of (46), followed by hypobromite oxidation of the product, afforded 3-hydroxy-2-methylpropanoic acid, whose hydrazide (48) was shown to be enantiomeric with the known hydrazide" of -configuration. The hydrazide from monocrotaline therefore has the S-configuration and monocrotalic acid has the R-configuration at C-4. 

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