177771-88-9 4,7-Methano-1H-indene-2-carboxylic acid, octahydro-, ethyl ester 4,7-Methanoindan-2-carboxylic acid, hexahydro-, ethyl ester 68140-53-4 EINECS 268-805-1 Ethyl octahydro-4,7-methano-1H-indene-2-carboxylate