PROCESS FOR PREPARING ASPARTYL PEPTIDES AND NEW ASPARTYC ACIDDERIVATIVES USABLE IN THE SYNTHESIS THEREOF

摘要

Preparation of aspartyl peptides having the general formula (IV), wherein -NHR is an amino acid rest or a peptide rest. According to the invention, an aspartic acid beta -monoester of the general formula (I) wherein R1 is hydrocarbonaceous radical carrying optionally an activator substituent is reacted with a beta -bicarbonylated compound such as ethyl acetate acetyl to form an enamine on which a coupling is effected with an amino acid or a derivative such as an ester or a peptide optionally previously protected, and if required the protection groups are eliminated. The process enables to obtain alpha -aspartyl peptides free of the isomer beta .