Hydrogenation of Acids and Esters to the corresponding Alcohols

Reaction LXIV. (e) Catalytic Hydrogenation of Acids and Esters to the Corresponding Alcohols. (Z. a., 44, 714 Am. Soc., 53, 1095 B., 64, 2051.)—Various catalysts are used, e.g., copper chromite, nickel, at temperatures of 250°—300°, and usually high pressures (200 atm.). Temperatures of 350° and over result in hydrocarbon formation. 

Under certain conditions hydrogenation may be confined to the —COOH group, e.g., oleic acid — oleyl alcohol. 

Salts of the hydrogen sulphate esters of these higher alcohols are used extensively in the textile industries, those of the unsaturated alcohols possessing superior properties in certain respects. 

The reaction is widely applied to the production of higher alcohols from oils and fats. 

The reductions in this section are mostly those of acids to aldehydes they are naturally few, since oxygenated compounds are not usually obtained by reduction of more highly oxygenated substances the reverse process is much more often employed. 

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