(5S)-5-methyl-5-propan-2-yloxolan-2-one

S-phenyl 4-oxopentanethioate

4-[(2,4-二硝基苯基)亚肼基]戊酸

methyl 4-[(2,4-dinitrophenyl)hydrazinylidene]pentanoate

3-[(4-methoxyphenyl)methylidene]-4-oxopentanoic acid