4-09-00-00224 (Beilstein Handbook Reference) 5-Norbornene-2-carboxylic acid, exo- 934-30-5 BRN 3196451 Bicyclo(2.2.1)hept-5-ene-2-carboxylic acid, exo- (9CI) NSC 155661 exo-5-Norbornene-2-carboxylic acid exo-Bicyclo(2.2.1)hept-5-ene-2-carboxylic acid