Synthesis and Biological Evaluation of Novel -2′-Azido-2′,3′-dideoxyarabinofuranosyl-4′-thiopyrimidines and purines

Novel -2′-azido-2′,3′-dideoxyarabinofuranosyl-4′-thiopyrimidines and purines have been synthesized, starting from -xylose via azidation at the 2′-position as a key step. Most of the final nucleosides exhibited toxicity-dependent anti-HIV-1 activity, among which -α-adenine analogue 3h was found to be the most cytotoxic.