The novel farnesyl diphosphate (FPP) analog 13-methylidenefarnesyl diphosphate (3-VFPP, 4) was designed as a potential mechanism-based inhibitor of the FPP-utilizing enzyme protein-farnesyl transferase (PFTase). A six-step stereoselective route to 3-VFPP is described. The key step in the synthetic sequence involved the stereoselective coupling of vinyl triflate 16 with vinyltributyltin using Pd (AsPh3) 2 and CUI as catalysts to afford ...