Optically pure oxodicyclopentadiene (KDP) has been prepared in both enantiomeric forms from racemic 4-tert-butoxycyclopent-2-en-1-one in three ways starting from 4-tert-butoxycyclopent-2-en-1-one involving contra-steric Diels-Alder reaction and lipase-mediated enantiospecific kinetic transesterification as key steps.