Abstract
The cage triketone 2 revealed different reactivities toward the thermal condition according to the substituents : the cyclobutane ring cleavage for alkyl substituents and the decarbonylation for methoxycarbonyl ones. The X-ray crystallographic study for the derivative of 2b showed a significantly long (1.635 (7) Å) C (Ph)-C (Ph) σ bond. The reaction mechanisms are discussed in terms of frontier molecular orbital (FMO) theory combined with the results of molecular mechanics and semiempirical MNDO molecular calculations.
