Z-Glu(OtBu)-OH is widely used in peptide synthesis, particularly in solid-phase peptide synthesis (SPPS) methods. It serves as a protected form of glutamic acid, where the tert-butyl ester group protects the carboxyl side chain, preventing unwanted reactions during peptide chain assembly. This protection allows for selective deprotection and activation of specific functional groups, enabling the precise construction of complex peptides. It is especially valuable in synthesizing peptides with glutamic acid residues, ensuring the integrity of the side chain functionality. Additionally, it is employed in the development of peptide-based pharmaceuticals, bioactive peptides, and research tools for studying protein interactions and enzymatic processes. Its stability and compatibility with various coupling reagents make it a reliable building block in organic and medicinal chemistry.