Protection of D-alaninol (I) with di-tert-butyl dicarbonate gave rise to carbamate (II). Subsequent Mitsunobu coupling of (II) with 2-mercaptobenzothiazole (III) furnished thioether (IV), which was deprotected with HCl in EtOAc. The resulting amine (V) was condensed with dichloropurine (VI) to afford the chloroadenosine derivative (VII). Finally, cleavage of the acetate esters of (VII) was achieved by treatment with NaOMe in MeOH.

4-Hydroxypiperidine (I) was protected as the tert-butyl carbamate (II) upon treatment with (Boc)2O. Subsequent Mitsunobu coupling of (II) with diphenyl disulfide using tributylphosphine and diethyl azodicarboxylate afforded thioether (III). Acid deprotection of the Boc group of (III), followed by nitrosation of the resulting amine (IV) gave N-nitrosopiperidine (V). Further reduction of (V) with LiAlH4 yielded hydrazine (VI). Condensation of (VI) with dichloropurine derivative (VII) produced piperidinyladenosine (VIII). Debenzoylation of the tribenzoate ester (VIII) with methanolic ammonia gave (IX). Then, chlorination at position 5' with concomitant formation of the 2',3' cyclic sulfite (X) by reaction with thionyl chloride and pyridine was followed by sulfite hydrolysis with methanolic ammonia to yield the title compound.