For comparison, the furanosyl compound 9-(2'-deoxy-2'-fluoro-/3-~ arabinofuranosyl) guanine (17, AF'G) was prepared by coupling 2-amino-6-chloropurine with 2-deoxy-2-fluoro- 3, 5-di-O-benzoyl-a-~-arabinofuranosyl bromide followed by base hydrolysis. The 6'a-fluor0 derivative lld exhibited comparable activity to that of acyclovir (ACV) against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) in vitro but was> 30-fold more active than ACV ...