3-ethylpentane, oxidation

Ethyl p-nitrophenyl benzenethionophosphate, see EPN Ethyl p-nitrophenyl benzenethiophosphonate, see EPN Ethyl p-nitrophenyl ester, see EPN Ethyl p-nitrophenyl phenylphosphonothioate, see EPN O-Ethyl O-4-nitrophenyl phenylphosphonothioate, see EPN O-Ethyl O-p-nitrophenyl phenylphosphonothioate, see EPN Ethyl p-nitrophenyl thionobenzenephosphate, see EPN Ethyl p-nitrophenyl thionobenzenephosphonate, see EPN Ethylolamine, see Ethanolamine Ethyl oxide, see Ethyl ether Ethyl parathion, see Parathion Ethylpentamethylene, see Ethylcyclopentane 2-Ethylpentane, see 3-Methylhextane O-Ethyl phenyl / nitrophenyl phenylphosphorothioate, see EPN... 

Secondly, from studies of the yields of the conjugate oxiran and alkene found during the oxidation of 3-ethylpentane, see Sect. 3.2.2(a)(ii), Cullis and co-workers [86] have shown that if the values of the Arrhenius parameters for reaction (15)... 

A recent investigation of the oxidation of 3-ethylpentane [86] and of 3-methylpentane [80] over a wide range of initial conditions has confirmed this conclusion. Thus, over the temperature range 295—405 °C, the conjugate alkenes and oxirans are primary products and the ratio of their yields is constant, except in the later stages of reaction where their own further reaction is extensive. For these higher molecular weight (Cs—C7)... 

Cullis and co-workers [80,85,86] have shown that group shifts involving ethyl radicals may also take place. Thus the presence of small yields (ca. 2 %) of 4-methylhexan-3-one and heptan-3-one in the products of the cool-flame oxidation of 3-ethylpentane show that the 3-ethyl-3-... 

Thus, in the case of 3-ethylpentane initial attack at a secondary C—H bond may always be followed by oxygen addition and 1 5 H-transfer involving another secondary C—H bond. Furthermore, since the initial attack is unselective during cool-flame oxidation a considerable proportion of primary alkylperoxy radicals will be formed from this alkane and these may all undergo the relatively easy isomerization involving 1 5-hydrogen transfer from a tertiary C—H bond... 

In contrast, compounds arising from /3-scission of C—C bonds are the major products formed during the oxidation of 3-ethylpentane, their yields being ca. 3 times as large as those of the corresponding oxetans. /3-Scission decomposition of /3-hydroperoxyalkyl radicals competes effectively, therefore, with their decomposition by cyclization to oxetans. 

The relatively most frequent reaction is oxidation at the methinegroup giving tertiary alcohols as main products and secondary alcohols and ketones as minor products [902]. The hydroxylation occurs predominantly with retention of configuration [329, 620]. The oxidation of 3-ethylpentane with benzyltriethylammonium permanganate yields 24% of 3-ethyl-3-pen-tanol, 25% of 3-ethyl-2-pentanone, and 25% of 3-pentanone [902]. Under the same conditions, methylcyclohexane yields 72% of 1-methylcyclo-hexanol and 3% of 2-methylcyclohexanone [902]. 

The chemical (Gif system) and the electrochemical conversion (Gif-Orsay system) have been compared in the oxidation of six saturated hydrocarbons (cyclohexane, 3-ethylpentane, methylcyclopentane, cis- and traus-decalin and adamantane). The results obtained for pyridine, acetone and pyridine-acetone were similar for both systems. Total or partial replacement of pyridine for acetone affects the selectivity for the secondary position and lowers the ratio ketone secondary alcohol. The formation of the same ratio of cis- and traws-decal-9-ol from either cis- or trans-deca in indicates that tertiary alcohols result from a mechanism essentially radical in nature. The C /C ratio between 6.5 and 32.7 rules out a radical mechanism for the formation of ketones and secondary alcohols. Ratios of 0.14 and 0.4 were reported for radical-type oxidations of adamantane and cis-decalin. Partial replacement of pyridine by methanol, ethanol or f-propanol results in diminished yields and a lower selectivity. Acetone gives comparable yields however, the C /C ratio drops to 0.2-10.7. 

The kinetic deuterium isotope effects at 25 ""C in the oxidation of cyclohexane (C-C6H12/C-C6D12) and t-butane (CH3)3CH/(CH3)3CD with Cr03 in 45-60% H2SO4 have been found to be 4.7 0.4. kjk, for 3-ethylpentane and diphenyl-... 

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