2'-Fluorosugar analogues of the highly potent anti-varicella-zoster virus bicyclic nucleoside analogue (BCNA) Cf 1743

We report the preparation of 2'-a-F, 2'-ß-F and 2',2'-difluoro analogues of the leading anti-varicella zoster virus (VZV) pentylphenyl BCNA Cf 1743. VZV thymidine kinase showed the highest phosphorylating capacity for the ß-fluoro derivative, that retained equal antiviral potency as the parent compound. In contrast, the a-fluoro- and 2',2'-difluoro BCNA derivatives were markedly less (~100-fold) antivirally active.