Synthesis of C-60(O)(3): An Open-Cage Fullerene with a Ketolactone Moiety on the Orifice

Abstract

Four isomers are currently known for the trioxygenated fullerene derivative C-60(O)(3), three regioisomers with all of the oxygen addends as epoxy groups and the unstable ozonide isomer with a 1,2,3-trioxlane ring. Here we report the synthesis of an open-cage isomer for C-60(O)(3) with a ketolactone moiety embedded into the fullerene skeleton through a three-step procedure mediated by fullerene peroxide chemistry. Two fullerene skeleton carbon-carbon bonds are cleaved in the process. The open-cage derivative C-60(O)(3) can be converted back to C-60 through deoxygenation with PPh3. Single crystal X-ray structure confirmed the open-cage structure.