Synthesis and antiviral properties of (Z)-5-(2-bromovinyl)-2'-deoxyuridine

(Z)-5-(2-Bromovinyl)uracil was obtained by photoisomerization of the E. isomer. Similarly, (E)-5-(2-bromovinyl)-2'-deoxyuridine gave the required Z isomer. (Z)-5-(2-Bromovinyl)-2'-deoxyuridine is much less active against herpes simplex virus type 1 (HSV-1) and somewhat less active against herpes simplex virus type 2 than is the E isomer. Both isomers show similar activity against vaccinia virus. Therefore, the highly potent and selective activity of (E)-5-(2-bromovinyl)-2'-deoxyuridine against HSV-1 is due to its E configuration.