5-[(4-氯苯基)氨基]-5-氧代戊酸

(Z)-6-cyano-7-ethoxy-5-hydroxy-7-oxohept-5-enoic acid

5-(4-联苯)吉草酸

5-(N-methylanilino)-5-oxopentanoic acid

5-[2-[2-[2-[2-(4-carboxybutanoyloxy)ethoxy]ethoxy]ethoxy]ethoxy]-5-oxopentanoic acid