Cyclohexane-1,2-diol, oxidation adipic acid

The production of alcohols by the catalytic hydrogenation of carboxylic acids in gas-liquid-particle operation has been described. The process may be based on fixed-bed or on slurry-bed operation. It may be used, for example, for the production of hexane-1,6-diol by the reduction of an aqueous solution of adipic acid, and for the production of a mixture of hexane-1,6-diol, pentane-1,5-diol, and butane-1,4-diol by the reduction of a reaction mixture resulting from cyclohexane oxidation (CIO). 

Alicyclic compounds, such as cyclohexane, are also susceptible to oxidation, in this case first to cyclohexanol and then to /rans-cyclohexane-1,2-diol, cyclohexaone, and adipic acid. 

Vicinal diols have been cleaved with molecular oxygen using a ruthenium pyrochlore oxide catalyst. Cyclohexane-1,2-diol was oxidized to adipic acid in 72% yield with this catalyst system (Eqn. 21.38). Cyclohexanone was also converted to adipic acid under these conditions. 5... 

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