Regiochemically Controlled Synthesis of a β-4-β' [70]Fullerene Bis-Adduct.

A β-4-β' C70 bis-adduct regioisomer and an uncommon mono-adduct β-malonate C70 derivative were synthesized by using a Diels-Alder cycloaddition followed by an addition-elimination of bromo-ethylmalonate and a retro-Diels-Alder cycloaddition reaction. We also report the regioselective synthesis and spectroscopic characterization of Cs-symmetric tris- and C2v-symmetric tetra-adducts of C70, which are the precursors of the mono- and bis-adduct final products.