Solid phase synthesis of peptidyl aldehydes from C-terminal thiazolidinyl peptides

Summary Peptidyl aldehydes are potent transition state analogue inhibitors of cysteine and serine proteinases. The aldehyde function has recently been used for chemoselective peptide ligation. The preparation of peptidyl aldehydes on a solid support requires that the aldehyde be masked during peptide elongation and generated in a final step under mild conditions. We report here the preparation of peptidyl aldehydes by copper salt-mediated neutral hydrolysis of the corresponding C-terminal thiazolidinyl peptides which were elongated on a solid support.