The invention relates to a process for preparing cyclohexanedicarboxylic
acids or derivatives thereof, such as esters and/or anhydrides,
encompassing the reaction of diene/maleic acid anhydride mixtures, in
particular of butadiene/maleic acid anhydride mixtures or of mixtures of
maleic acid anhydrides and C5-dienes to give alkyl-substituted or
unsubstituted cyclohexenedicarboxylic acid anhydrides in the condensed
phase, ester formation, and then hydrogenation to give the corresponding
cyclohexanedicarboxylic acid derivative, and also to the use of the
cyclohexanedicarboxylic acids or derivatives thereof prepared according
to the invention as plasticizers for plastics.