Used in peptide synthesis, particularly for the protection of cysteine residues during the creation of complex peptides. It ensures the thiol group of cysteine remains stable and unreactive until the final stages of synthesis, preventing unwanted side reactions. This is especially useful in the production of peptides with disulfide bonds, which are common in bioactive peptides and proteins. Additionally, it facilitates the synthesis of peptides with specific stereochemistry, as it is the D-form of cysteine, allowing for the creation of peptides with tailored biological activity. Its application is critical in pharmaceutical research, where precise peptide structures are required for drug development and biochemical studies.