Dehydroabietic acid 5 was converted to the exocyclic olefin 7 by applying the Barton decarboxylation protocol. The latter served as a key intermediate for the stereoselective synthesis of a variety of ring-A functionalized derivatives. Compounds 13 and 16 turned out to be active against the herpes virus (HSV-2) in the standard plaque assay and seem to interfere with an early event in viral replication.