.alpha.-Ketobutric acid .alpha.-Ketobutyric acid .alpha.-Oxo-n-butyric acid .alpha.-Oxobutyrate .alpha.-Oxobutyric acid 2-Ketobutyric acid 2-Oxobutanoic acid 2-Oxobutyric acid 600-18-0 Butanoic acid, 2-oxo- Butyric acid, 2-oxo- Formic acid, propionyl- Ketobutyrate NSC60533 Oxobutyrate Pyruvic acid, methyl-