Chemical radiation studies of 8-bromo-2'-deoxyinosine and 8-bromoinosine in aqueous solutions.

LILIANA B. JIMENEZ

CHEMISTRY-A EUROPEAN JOURNAL

Wiley-VCH Verlag GmbH & Co.

Año: 2006 vol. 12 p. 7684 - 7684

0947-6539

he reactions of hydrated electrons (eaq-) with 8-bromo-2´-deoxyinosine and 8-bromoinosine have been investigated by radiolytic methods coupled with product studies and have been addressed computationally by means of BB1K-HMDFT calcns.  Pulse radiolysis revealed that one-electron reductive cleavage of the C-Br bond gives the C8 radical followed by a fast radical translocation to the sugar moiety.  Selective generation of a C5´ radical occurs in the 2´-deoxyribo deriv., whereas in the ribo analog the reaction is partitioned between the C5´ and C2´ positions with similar rates.  Both C5´ radicals undergo cyclizationswith rate consts. of 1.4  105 and of 1.3  104 s-1, resp.  The redox properties of radicals have also been investigated.  A synthetically useful photo-reaction has also been developed as a one-pot procedure that allows the conversion of 8-bromo-2´-deoxyinosine to 5´,8-cyclo-2´-deoxyinosine in a high yield and a diastereoisomeric ratio (5´R)/(5´S) of 4:1.  The present results a