Process for the resolution of rac-2-oxotricyclo�2.2.1.0.sup.3,5 !heptane-7-carboxylic acid esters using lipase from candida.Compounds of the formula I ##STR1## in which R.sup.1 has the meanings mentioned, may be obtained in isomerically pure form from enantiomer mixtures or racemic mixtures by reacting the compound of the formula I in the presence of a lipase or esterase from porcine liver, porcine pancreas, bovine pancreas or from microorganisms such as Candida, Pseudomonas, Mucor, Rhizopus and Aspergillus, or proteases from Bacillus in the presence of water and, if desired, a cosolvent and separating from one another the esters and acids present in the solution obtained.