Stereoselective synthesis of individual isomers of Leu-enkephalin analogues containing substituted β-turn bicyclic dipeptide mimetics

Abstract

Novel constrained β-turn dipeptide mimetics, 8-phenyl thiaindolizidinone amino acids 3, have been synthesized stereoselectively and incorporated into Leu-enkephalin peptides as a replacement of dipeptide Gly–Phe to afford four individual isomers of Leu-enkephalin analogues 6.