Photooxygenation of silyl-modified azafulleroids 1b and 1c open-cage fullerenes having keto lactam 2b and 2c or diketo imide 3b and 3c functional groups on 11- or 15-membered ring orifices. The high reactivity of the bridgehead double bonds was estimated by pi-orbital axis vector (POAV) analysis comparing the bisfulleroid derivatives 5d, 5e, 6d, and 6e.