SYNTHESIS OF PHENYL-SUBSTITUTED VALINOMYCINS

The synthesis is described of a modified valinomycin, which incorporat es phenyl groups located around the exterior belt. The synthesis is ac complished by a build up of linear fragments using both dicyclohexylca rbodiimide- and pentafluoroester- methods of coupling. The final cycli sation is accomplished using the pentafluoroester protocol. The modifi ed valinomycin is shown to be an effective ligand for complexation wit h potassium ion. Both nmr and electrochemical studies show that the mo dified valinomycin has similar properties to the parent valinomycin, a nd hence phenyl substitution around the periphery does not disrupt the network of hydrogen bonds which influence, the conformation of valino mycins.