Efficient Cage-Opening Cascade Process for the Preparation of Water-Encapsulated [60]Fullerene Derivatives

Cage-opened fullerenes with 18-membered-ring orifices have been prepared starting from fullerene-mixed peroxides. The key transformation involves a cascade sequence including a deketalization, a S_N2′ epoxide opening reaction, and a formal 3,3-σ rearrangement. The 18-membered-ring orifice is big enough for water encapsulation under mild conditions. Single crystal X-ray structures were obtained for both the empty and water-encapsulated fullerene derivatives.