Valeric Acids
Valeric Acids
monobasic saturated organic acids with the general formula C4H9COOH, colorless liquids having a characteristic odor. Four isomers of valeric acids are possible, depending upon the structure of the hydrocarbon radical; their characteristics are given in Table 1.
| Table 1. Isomers of valeric acids | ||
|---|---|---|
Acid | Melting point | Boiling point |
Valeric CH3(CH2)3COOH................ | -34.5 | 186.3 |
Isovaleric (CH3)2CHCH2COOH................ | -37.6 | 176.7 |
Methyl ethyl acetic CH3CH2CH(CH3)COOH................ | -80 | 177 |
Trimethylacetic (CH3)3CCOOH................ | 35.4 | 163.7 |
Methyl ethyl acetic acid, containing an asymmetrical carbon atom, exists in (+), (-), and racemic forms; the (+) form, in the form of esters, is contained in essential oils. Of greatest importance are the isovaleric and methyl ethyl acetic acids, which are obtained chiefly by the oxidation of isoamyl alcohols.
Esters of valeric acid and fatty alcohols having a fruity scent are used in the food-processing industry; esters of valeric acid and aromatic or terpene alcohols are used in per- fume manufacture.