PREPARATION OF ENDORPHIN

摘要

PURPOSE:To prepare the title compound having definite optical purity, and useful as an analogesic agent, a growth hormone secretive agent, etc. for clinical use, by the fragment condensation of peptides (some of which are novel) containing threonine or isoleucine as a carboxy-terminated amino acid. CONSTITUTION:A (protected) endorphin having an N-terminated amino acid sequence of formula III, is prepared by (1) reacting a novel compound II with a peptide residue having protected N-terminals, optionally reacted with a compound I (R1-4, R6-7 are protecting group), and (2) eliminating the protecting groups, if necessary. As an alternative process, a polypeptide having an N-terminted amino acid sequence of formula V is prepared by reacting the above peptide residue with a compound IV. Both of the reactions are preferably carried out in the presence of dicyclohexyl carbodiimide and N-hydroxy-5-norbornene-2,3-dicarboxylic imide, at -30-50 deg.C.