The conformationally locked nucleoside,(north)-methanocarbathymine (1a), is a potent and selective anti-herpes agent effective against herpes simplex type 1 (HSV1) and type 2 (HSV2) viruses. Hereby, we report on the synthesis and biological evaluation of a small set of 5-substituted pyrimidine nucleosides belonging to the same class of bicyclo [3.1. 0] hexane nucleosides. Both the 5-bromovinyl (4) and the 5-bromo analogue (3) appeared to ...
