Regioselectivity of Multiple Cyclopropanations of C60 and Introduction of a General Bond-Labeling Algorithm for Fullerenes and Their Derivatives

A computational (AM1) analysis is presented which shows that the observed regioselectivities of multiple cyclopropanations of C60 are due to orbital‐allowed processes. Next to the coefficients of frontier orbitals the characteristic cage distortions of the oligomethanofullerenes are discussed. For further experimental corroboration the synthesis and characterization of an unsymmetrical trisadduct with a I, eI, III*‐addition pattern are described. Moreover, since a systematic and descriptive assignment of addition patterns in derivatives of C60 and higher fullerenes becomes more and more important, a simple and general algorithm is introduced, which enables unambiguous bond labeling of both [6,6]‐ and [5,6]‐bonds as well as the assignment of the absolute configuration of any fullerene derivative.