Endothiopeptides

Abstract

N-protected dipeptide esters have been converted into the corresponding protected endothiopeptides 1 using Lawesson's reagent, 2 1 . Methods of amino and carboxyl deprotection, and coupling of the thiopeptides with amino acids have been defined and used to prepare two examples of novel N-protected endothio tri peptide esters with a single thioamide link. Possible effects of the thioamide bond on the conformation of the dipeptide esters are considered.