[2+2] Photocycloaddition of 3-Alkoxycoumarins with C60

Abstract

The [2+2] cycloaddition of 3-alkoxycoumarins with C60 proceeded stereoselectively under photoirradiation conditions to produce a new class of fullerene fused oligocyclic cyclobutane products. This reaction seems to progress via radical ion pair intermediates that arise from the SET processing of 3-alkoxycoumarins with the excited form of C60.