异戊酸(結構式:(CH3)2CHCH2COOH)，是一种含有5个碳原子的短链饱和脂肪酸。透明液体，可溶于水。 3-Methylbutanoic acid, or more commonly isovaleric acid, is an organic compound with the formula (CH3)2CHCH2CO2H. It is sometimes classified as a fatty acid. It is a colourless liquid that is sparingly soluble in water, but highly soluble in most common organic solvents. The compound occurs naturally, including in essential oils.