Synthesis and Biological Activity of 9-β-D-Arabinofuranosyladenine Cyclic 3′,5′-Phosphate and 9-β-D-Arabinofuranosylguanine Cyclic 3′,5′-Phosphate

8,2′-Anhydro-8-hydroxy-9-β-D-arabinofuranosylpurine cyclic 3′,5′-phosphates (Va,b) have been synthesized by intramolecular cyclization of the corresponding 8-hydroxy-2′-O-tosyl-9-β-D-ribofuranosylpurine cyclic 3′,5′-phosphates (IVa.b). A reductive cleavage of anhydro derivatives Va,b with H₂S followed by Raney nickel desulfurization provided 9-β-D-arabinofuranosyladenine cyclic 3′,5′- (VIIa, c-ara-AMP) and 9-β-D-arabinofuranosylguanine cyclic 3′,5′-phosphate (VIIb, c-ara-GMP). c-Ara-AMP is cytotoxic to KB and HeLa cells in culture and exhibits significant antiviral activity against herpes simplex type 1 and type 2 infections. c-Ara-GMP is cytotoxic to KB, Sarcoma 180, and HeLa cells. Unlike c-ara-AMP, c-ara-GMP did not exhibit any significant antiviral activity.