C-protected amino acid

C-protected amino acids refer to the introduction of a certain protecting group on the C-terminus (ie, carboxyl end) of the amino acid molecule to prevent this part from undergoing unnecessary reactions or interference in chemical reactions. This protection strategy is often used in organic synthesis and peptide synthesis, especially in the synthesis of polypeptides, to ensure the selectivity of different reaction steps. By properly protecting the carboxyl group of amino acids, side reactions can be effectively avoided and the selectivity and efficiency of synthesis can be improved. Different protecting groups can be selected according to different synthesis conditions and requirements. Common protecting groups include ester groups (such as methyl esters, ethyl esters), tert-butyl esters, and aromatic esters.