Z-Asp(OtBu)-OSu is widely used in peptide synthesis as a protecting group for aspartic acid. It helps to prevent unwanted side reactions during the formation of peptide bonds, ensuring the selective coupling of amino acids. This compound is particularly valuable in solid-phase peptide synthesis (SPPS), where it provides stability and control over the reaction process. Its tert-butyl ester group can be easily removed under mild acidic conditions, making it a versatile tool for constructing complex peptides and proteins. Additionally, it is employed in the preparation of peptide-based drugs, biomaterials, and research compounds, contributing to advancements in medicinal chemistry and biotechnology.