3- Methylcyclohexene allylic oxidation

Chromic acid itself has been used in the oxidation of alkenes and in some cases allylic oxidation products were observed for example, cyclohexene was converted to cyclr xenone in 37% yield and l methylcyclohexene was oxidized to a mixture of enones (Scheme 16)." ... 

The stereospecific conversion of cyclohexene into the corresponding amido selenide 54 is illustrated in Scheme 8. These amidoselenenylation reactions are commonly employed for the preparation of allylic and saturated amides by oxidative or reductive deselenenylation. Propionitrile, butyronitrile, benzonitrile and ethyl cyanoacetate may be used in place of acetonitrile. Styrene gave poor results and other electron-rich olefins such as 1-methylcyclohexene or 2,3-di-methylbut-2-ene did not give the amidoselenenylation products. The reaction can also be effected starting from the hydroxy- or methoxyselenenylation products of alkenes, in the presence of water and trifluoromethanesulfonic acid in this case the nitriles are used in stoichiometric amounts [48c]. This methodology was employed to prepare the amidoselenenylation products of styrene, 55, and of electron-rich olefins. It was necessary, however, to replace the phenyl-... 

Epoxides may undergo rearrangement in the presence of protic or Lewis acids to give carbonyl compounds. However, the nature of the products may depend quite subtly on the reaction conditions. For example, 1-methylcyclohexene oxide has been reported to give the ring-contracted aldehyde as the major product with lithium bromide, but with lithium perchlorate, 2-methylcyclohexanone is the major product (Scheme 2.22a). In the presence of a strong base such as lithium diethylamide, an allylic alcohol may be formed from an epoxide (Scheme 2.22b). 

Japanese authors have made comprehensive investigations of the rearrangements of oxiranes in the presence of solid acids, bases, and salts.The model compounds employed were cyclohexene oxide and 1-methylcyclohexene oxide. The effects of the acidic and basic properties of the catalysts on the selectivity were interpreted on the basis of the products obtained. The main products are carbonyl compounds and allyl alcohol isomers. Rearrangements of limonene oxide over acids and bases were studied on five different types of Al203 similar research has been carried out on 2- and 3-carene oxides, cis- and trans-carvomenthene oxides and a-pinene oxide. ... 

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