(2S)-2-ethyl-2-hydroxy-3-oxobutanoate
(2S)-2-ethyl-2-hydroxy-3-oxo-butanoate
(2S)-2-ethyl-2-hydroxy-3-keto-butyrate
(S)-2-Aceto-2-hydroxybutanoate
(S)-2-Hydroxy-2-ethyl-3-oxobutanoate