Stepwise conversion of a 10‐membered diketo open‐cage [60]fullerene to a 10‐membered keto‐lactone open‐cage [60]fullerene

Abstract The chemical reactivity of a 10‐membered diketo open‐cage fullerene C 60 (O) 2 (OO t Bu) 4 was investigated in an effort to reveal the unique reaction pattern of fullerene derivatives. Selective cleavage of peroxo O−O bonds was observed under thermolysis in the presence of iodine to form epoxy groups around the orifice. Opening of the epoxy groups leads to vicinal diol moiety, oxidation of which resulted in a new 10‐membered keto‐lactone open‐cage fullerene derivative. Single crystal X‐ray diffraction analysis showed that the size of the rectangular orifice is around 2.96×4.66 Å.