Synthesis of N-formyl-3,4-di-t-butoxycarbonyloxy-6(trimethylstannyl)-L-phenylalanine ethyl ester and its regioselective radiofluorodestannylation to 6-[18F]fluoro-1-dopa

A process is revealed for forming a 6-fluoro derivative of compounds in the L-Dopa family comprising the steps of protecting the groups attached to the benzene ring in the compound followed by serially reacting the protected compound with (a) iodine and silver trifluoroacetic acid; (b) Bb3; (c) dit-butyldicarbonate; (d) hexamethyltin; (e) a fluoro compound; (f) hydrobromic acid; and (g) raising the pH to ≤7. 1 fig