Preparation of [60]fullerene tris-malonate adducts by addend removal from higher adducts via the electrochemical retro-Bingel reaction

Systematic application of the electrochemical retro-Bingel reaction to tetrakis-, pentakis- and hexakis-malonate adducts of C-60, produced tris-adducts in ca. 30% yield. Of the tris-adducts obtained, the (trans-4, trans-2, e) and the (trans-3, trans-4, e) isomers were the major products, while unexpectedly, the (e, e, e) and (trans-3, trans-3, trans-3) isomers were formed in relatively small amounts. New tetrakis-adducts were also formed via the isomerization reaction as indicated by HPLC studies.