6,7-dihydro-5H-cyclopenta[b]pyran-2-one

6,7-dihydrocyclopenta[c]pyran-3[5H]-one

2-氯-4-(三氟甲基)苯乙酸

2-chloro-4-(trifluoromethyl)phenylacetic acid tert-butyl-ester

tert-butyl 2-hydroxy-4-methoxy-6-methylbenzoate