Two new carboacyclic nucleoside analogues, 9-[4-hydroxy-3-(hydroxymethyl)-2-butenyl] adenine(6) and 9-[4-hydroxy-3-(hydroxymethyl)-2-butenyl] guanine (51, modeled on the unsaturated carbocyclic nucleoside analogue neplanocin A (2), have been synthesized and tested for antiviral activity against HSV-2 and, in the case of 6, for activity against influenza and in vitro inhibition of S-adenosylhomocysteine hydrolase. The synthesis was ...