trans-1,2-Cyclopentanedicarboxylic Acid is used as a reagent in the synthesis of isoxazoline and oxazoline analogs of CDA54 as voltage gated sodium channel blockers. trans-1,2-Cyclopentanedicarboxylic Acid is also a reagent in the preparation of cyclopentanedicarboxamide sodium channel blockers as a potential treatment for chronic pain.