Carbon Cluster Compounds. Generation and Reorganization of the Homobullvalenyl Cation, an 11-Fold Degenerate Species

Treatment of 4-bromo-4-trifluoroacetoxytetracyclo[4.3.2.02.9.03,5]undeca-7,10-diene (3) with sodium borohydride gave endo-4-hydroxytetracyclo[4.3.2.02,9.03,5]undeca-7,10-diene (5). Acetolysis of the corresponding triflate (9) proceeded at a rate virtually identical with those of the dihydro and tetrahydro derivatives 10 and 11. Solvolysis of the specifically deuter-ated triflate 9-d gave the alcohols 12 and 13 which were shown to have a statistical distribution of deuterium among the 11 skeletal carbons. This scrambling process has been interpreted in terms of multiple rearrangement paths of the intermediate homobullvalenyl and bicyclo[4.3.2]undecatetraenyl cations 1 and 2.