Abstract The reaction of 3-β-d-ribofuranosyllumazine, and its 6, 7-dimethyl and diphenyl derivatives was studied for anhydronucleoside formation with adjacent carbonyl groups of the aglycon. Various conditions led to selective 2, 2′-cyclization but no products possessing the less favored 4, 2′-structure were obtained. The best yields of 2, 2′- anhydro-3-β-d-arabinofuranosyllumazines were obtained from 3-(2, 3-O-carbonyl-5-O- ...