Preparation of Ketolactone and Bislactone [60]Fullerene Derivatives and Their Conversion into Open‐Cage Fullerenes with a 12‐ or 15‐Membered Orifice

Selective cleavage of the peroxo group in the fullerene mixed peroxide C 60 (O)(OO t Bu) 6 1 produces open‐cage fullerenes with ketone and lactone moieties on the rim of the orifice. Photolysis of 1 results in the ketolactone derivative 2 C 58 (CO)‐(COO)(O)(OO t Bu) 4 with an epoxide moiety. Thermolysis of 1 results in the formation of two other isomers, the bislactone 3 C 58 (COO) 2 (OO t Bu) 4 and the ketolactone 4 C 58 (CO)(COO)(O)(OO t Bu) 4 with a 1,4‐dioxepin‐5‐one moiety. Both alcohols and amines react with one of the lactone moieties of 3 and expand the 12‐membered orifice into a 15‐membered orifice. Only amines react with the lactone moiety of 4 and expand the 11‐membered orifice into a 12‐membered orifice. Total yield of the 15‐membered open‐cage compound can reach 8.9 % in three steps starting from C 60 . The products were characterized by spectroscopic data and X‐ray diffraction data.