α-Chymotrypsin-catalyzed peptide synthesis in frozen aqueous solution using N-protected amino acid carbamoylmethyl esters as acyl donors

In the α-chymotrypsin-catalyzed peptide synthesis in ice (−24 °C), the carbamoylmethyl (Cam) ester was found to be a useful acyl donor. This approach was also applied to the synthesis of peptides containing d-amino acids. A high diastereoselectivity towards the l-l peptide was observed when the racemic Cam ester was used.