Cleavage of protected amino acids and peptides from benzyl ester resins by transesterification with potassium cyanide in benzyl alcohol.

The nature of the protected amino acid or peptide attached to the Merrifield resin influences the rate of KCN-catalyzed transesterification in benzyl alcohol. Although crown ether complexes of KCN do not expedite the reaction, sterically hindered amino acids are readily transesterified in the presence of saturating concentrations of KCN at elevated temperatures.