Cyclisation radicalaire de la desoxy-2′-adenosine en solution aqueuse,sous l'effet du rayonnement gamma

5′,8-Cyclo-2′-deoxy-adenosine 2 has been identified as one of the principal products of gamma radiolysis of 2′-deoxyadenosine (G = 0.03 in the presence of oxygen; G = 0.05 in the absence of oxygen). This compound is likely to play a role in the phenomena of radio-induced mutation. ¹H-NMR studies at 250 MHz have shown the remarkable geometry of the compound since three coupling constants of the vicinal protons of the sugar fragment have not been detected. The study of the model has in fact shown that the corresponding protons form an angle close to 90°. The formation of 2 shows that the C8-N7 double bond is attacked by the radical on the carbon 5′ of 1, produced by the action of OH· radicals formed by the radiolysis of water.