Synthesis of l-(2-deoxy-2-fluoro-~-~-arabinofuranosyl) urac~ 1s containing a vinyl (4a), 2- halovinyl (4b-d), or ethyl substituent at C-5 was achieved. These nucleosides were found to be about a log order less active than 2 '-fluoro-5-iodo-ara-C (FIAC) against HSV-1, but they are much less cytotoxic against normal human lymphocytes than FIAC. Nucleosides 4a and 4e showed good activity against HSV-1 (EDw= 0.16 and 0.24 pM, respectively) and HSV- ...
