Efficient preparation of two tricyclic dienones, (1) and (2), in both enantiomeric forms has been developed by employing lipase-mediated resolution. A variety of natural products have been synthesized in enantiocontrolled manners by utilizing the former as a chiral equivalent of 2-cyclopentenone (as well as cyclopentadienone) and the latter as a chiral equivalent of 2-cyclohexenone (as well as 2,5-cyclohexadienone).