Ŝtefica Horvat, Lidija Varga-Defterdarović and Jaroslav Horvat
Novel hexose-related imidazolidin-4-ones are prepared by intramolecular rearrangements of monosaccharide esters in which D-mannose, D-glucose, or D-galactose are linked through their C-6 hydroxy groups to the endogenous opioid pentapeptide, leucine-enkephalin.