3-Carboxy-α,α-dimethylcyclopentaneacetic acid

2-(3-carboxycyclopentyl)-2-methylpropionic acid

3-(2-hydroxy-2-keto-1,1-dimethyl-ethyl)cyclopentanecarboxylic acid

3-(1-hydroxy-2-methyl-1-oxopropan-2-yl)cyclopentane-1-carboxylic acid

3-(1-hydroxy-2-methyl-1-oxo-propan-2-yl)cyclopentane-1-carboxylic acid