Abstract
N-(2-Hydroxyarylmethy1ene)amino acids have been coupled with amino acid esters to form sterically pure N-protected dipeptide esters. The protecting group can be removed by means of 80% acetic acid under conditions which leaves the t-butyloxycarbonyl protecting group intact. Biologically active peptides which are C-terminal partial sequences of substance P were prepared and were shown to have the expected vasodilator, spasmogenic and venoconstrictor properties.