Methylcyclohexane from 1-methylcyclohexene

Describe two simple chemical tests that could be used to distinguish methylcyclohexane from methylcyclohexene. (Hint Both tests produce color changes when alkenes are present.)... 

Figure 13.11 The 13C NMR spectrum of 1-methylcyclohexene, the E2 reaction product from treatment of 1-chloro-1-methylcyclohexane with base.

Likewise it is possible to differentiate between substituted and unsubstituted alicycles using inclusion formation with 47 and 48 only the unbranched hydrocarbons are accommodated into the crystal lattices of 47 and 48 (e.g. separation of cyclohexane from methylcyclohexane, or of cyclopentane from methylcyclopentane). This holds also for cycloalkenes (cf. cyclohexene/methylcyclohexene), but not for benzene and its derivatives. Yet, in the latter case no arbitrary number of substituents (methyl groups) and nor any position of the attached substituents at the aromatic nucleus is tolerated on inclusion formation with 46, 47, and 48, dependent on the host molecule (Tables 7 and 8). This opens interesting separation procedures for analytical purposes, for instance the distinction between benzene and toluene or in the field of the isomeric xylenes. 

The low temperature H-NMR spectra of 2-methyl-3,6-dihydro-2H-1,2-oxazine (239) gives a AG° favoring the /V-Meeq of 0.9 kcal mol", which is significantly less than that for the tetrahydro-l,2-oxazine (>1.9 kcal mol"1).246 This is similar to the decrease in conformational free energy of a methyl substituent on going from methylcyclohexane (1.7 kcal mol"1) to 4-methylcyclohexene (1.0 kcal mol 1),247 and the equilibrium 240 241 may represent a balance between lone-pair-Ti-bond repulsion in 240 and lone-pair-lone-pair repulsions in 241.246... 

An important consequence of the mechanism of this oxidation is that the stereo-isomeric features, resulting from the cis-addition of borane formulated previously (above), are retained in the final product, i.e. the overall reaction is highly stereospecific. Thus reaction of 1-methylcyclohexene with borane followed by oxidation gives frans-2-methylcyclohexan-l-ol.66... 

In a reaction resembling halohydrin formation (Section 6.17), vicinal haloethers are prepared from alkenes by reaction with an alcohol in the presence of halogens— usually bromine or iodine. This haleotherification proceeds through a cyclic halonium ion, which reacts with the alcohol. 1-Methylcyclohexene undergoes iodoetherification with ethanol in the presence of iodine to give ran -l-ethoxy-2-iodo-l-methylcyclohexane. 

The removal of the nitrogen atom from o-toluidine proceeds via two reactions by direct C-N bond cleavage of toluidine to toluene and ammonia (path 1), and by hydrogenation of o-toluidine to methylcyclohexylamine (path 2), which reacts further to methylcyclohexene, methylcyclohexane and ammonia [2]. Fig. 2 shows the influence of the initial partial pressure of o-toluidine on the selectivity for the products of these two pathways. Varying the initial partial pressure of o-toluidine in the reactant mixture did not affect the product selectivity. This indicates that either both reactions occur on the same site with the same order of reaction, or that o-toluidine has the same adsorption constant on the sites for path 1 and path 2. 

FIGURE 11.11 The 3C NMR spectrum of i-methylcyclohexene, the elimination reaction product from treatment of i-chloro-i-methylcyclohexane with a strong base. 

Devise a synthesis of 1-deutero-l-methylcyclohexane starting from 1-methylcyclohexene. 

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