The synthesis and conformational analysis of a pair of diastereoisomeric cyclic peptides with cis and transamide bonds, respectively

Abstract

N-Protected, conformationally constrained, eight-membered ring containing cyclic dipeptides derived from methyl cyclo-[(R)-cysteinyl-(R)-penicillamine] contain a cis amide bond, whilst the corresponding peptides derved from cyclo-[(R)-cysteinyl-(S)-penicillamine] contain a trans amide bond.