Cycloalkanes nitration

The reaction of acetyl nitrate with cyclic vinylsilanes gives 1-nitrocycloalkenes or 1,1-dinitro 2-nitrated cycloalkanes, depending on the ring size, as shown in Eqs. 2.37 and 2.38.73... 

Cycloparaffins may be nitrated to produce expl derivs. See also Cycloalkanes, Peroxide Derivatives... 

Table 5.31. Nitration and Nitrolysis of Alkanes and Cycloalkanes with N02+PF6 476...

Gasoline hydrocarbons volatilized to the atmosphere quickly undergo photochemical oxidation. The hydrocarbons are oxidized by reaction with molecular oxygen (which attacks the ring structure of aromatics), ozone (which reacts rapidly with alkenes but slowly with aromatics), and hydroxyl and nitrate radicals (which initiate side-chain oxidation reactions) (Stephens 1973). Alkanes, isoalkanes, and cycloalkanes have half-lives on the order of 1-10 days, whereas alkenes, cycloalkenes, and substituted benzenes have half- lives of less than 1 day (EPA 1979a). Photochemical oxidation products include aldehydes, hydroxy compounds, nitro compounds, and peroxyacyl nitrates (Cupitt 1980 EPA 1979a Stephens 1973). 

Nitrocyclohexane has been prepared by E. I. du Pont de Nemours Company by nitration of cyclohexane. Cyclohexane undergoes nitration and oxidation to give nitrocyclohexane and adipic acid along with smaller amounts of glutaric acid and succinic add. Nitration is accelerated by the addition of nitrogen dioxide. The process may be operated continuously in the liquid phase with 45-75 per cent nitric acid at temperatures of 100-200 C and pressures of 2-10 atm. This process is of particular interest in that oxidation products from cycloalkanes are usually S3rmmetrical di-carboxylic acids, which are of industrial importance. 

Mercuric salts induce oxidative rearrangement of cyclic alkenes and give cycloalkane carboxaldehydes. Cyclohexene, for example, gave cyclopentane carboxaldehyde (404) in 53% yield. Acyclic alkenes such as 2-butene can also be oxidized with mercuric sulfate and sulfuric acid, giving 2-butanone in this case.566 Thallium nitrate [T1(N03)3] is an important reagent for the oxidative rearrangement of cyclic alkenes.567 The reaction is not restricted to carbocyclic compounds, but can also be applied to heterocyclic compounds as shown by the oxidation of 3,4-dihydro-277-pyran (405) to the dimethyl acetal (406) in 65% yield.568... 

Whereas our studies centered so far primarily on the feasibility of the nitration of alkanes (cycloalkanes) with nitronium salte in aprotic solvent systems, once reactions are demonstrated they can, of course, also be carried out under more conventional conditions. Mixed acid (HNO -H-SO.) nitration of isobutane at 50° gave about 10% nitroproducts, with the relative ratio of CH3NO2, 28% ... 

A solution of a stable nitronium salt (generally the hexafluorophosphate NOa PF but also the hexafluoroantimonateNO SbFft ortetrafiuoroborate NO2BF4) in methylene chloride-tctramethylene sulfone solution was allowed to react with the alkane (cycloalkane), with usual precautions taken to avoid moisture and other impurities. Reactions were carried out at room temperature (25°C) in order to avoid or minimize the possibility of radical side reactions and/or protolytic cleavage reactions (tertiary nitroalkanes particularly readily undergo protolytic cleavage, even if the system initially is acid free but nitration forms acid). Data obtained are summarized in Table XXI. 

Diborane potassium hydroxide I silver nitrate Cycloalkanes from dienes... 

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