Catalytic amounts of bis(benzonitrile)palladium (II) chloride enhanced reaction rates of germacranolides Cope rearrangement to elemanolides. On the other hand, equimolecular amounts of the palladium complex transformed germacranolides into eudesmanolides. These phenomena provide a versatile procedure for the synthesis of eudesmanolides and elemanolides under relatively mild experimental conditions. Thus, (+)-stoebenolide and (+)-dehydromelitensin were alternatively synthesized starting out from (+)-salonitenolide.