2-(6'-carboxy-1'E-hexylidene)cyclopentanone methyl ester

methyl 7-(1-bromo-2-oxocyclopentyl)heptanoate

1-acetoxy-2-(6'-methoxycarbonylhexyl)-cyclopentene

Methyl 7-(2-oxocyclopentylidene)-heptanoate

Methyl 7-(2-chloro-5-oxo-1-cyclopentenyl)heptanoate