(S)-(-)-2-Propyl-4-pentynoic acid (S)-2-n-Propyl-4-pentynoic acid (S)-4-yn-VPA 136378-14-8 4-Pentynoic acid, 2-propyl-, (2S)- S(-)-4-Yn-valproic acid S-2-n-Propyl-4-pentynoic acid