3-methyl-2-oxobutanoic acid is a 2-oxo monocarboxylic acid that is the 2-oxo derivative of isovaleric acid. It has a role as a human metabolite and a Saccharomyces cerevisiae metabolite. It derives from a butyric acid. It is a conjugate acid of a 3-methyl-2-oxobutanoate. It is a tautomer of a 2-hydroxy-3-methyl-2-butenoic acid. Experimental spectrum in Natural Products Magnetic Resonance Database: [NP0000087](https://np-mrd.org/natural_products/422/submission_spectrum_view?spectrum_id=254&spectrum_type=real)