After 3',5'-di-O-protection of 8-bromoadenosine, the product was converted
to the arabinoside, which was successively treated with diethylaminosulfur
trifluoride (DAST) and acid to afford 8-bromo-2'-deoxy-2'-fluoroadenosine.
However, the formation of an 8,2'-anhydro compound was noted by treatment o
f the arabinoside with alkali. Finally, the 8-oxo analog was obtained from
the 8-bromo congener.