acetaldehyde + pyruvate => (S)-4-hydroxy-2-oxopentanoate
acetaldehyde + pyruvate => (s)-4-hydroxy-2-oxopentanoate
acetaldehyde + pyruvate => (S)-4-hydroxy-2-oxopentanoate
acetaldehyde + pyruvate => (s)-4-hydroxy-2-oxopentanoate