合成路线1

Treatment of adenosine (I) with H2O2 and HOAc affords N-oxide (II), which is converted into the benzyloxime (IV) via N-benzyloxyadenosine perchlorate (III). Treatment of (IV) with CS2 and NaOH in MeOH followed by separation by filtration and chromatography yields 2-thioadenosine (V), which is then converted into the sodium thiolate salt by treatment with NaOH in MeOH and condensed with benzylbromide (VI) in DMF, providing derivative (VII). Finally, conversion of (VII) into the target compound is achieved by following these steps: (i) treatment of (VII) with thiophosphoryl chloride (PSCl3) in pyridine; (ii) addition of a mixture of Bu3N and (Bu3NH+)2P2O7H2 in DMF; and (iii) treatment with TEAB and chromatographic separation of regioisomers.