This compound is widely used in solid-phase peptide synthesis (SPPS) as a protected amino acid derivative. The Fmoc (fluorenylmethyloxycarbonyl) group serves as a temporary protecting group for the amino group, while the OtBu (tert-butyl) group protects the carboxyl side chain of glutamic acid. This dual protection allows for selective deprotection during peptide chain assembly, ensuring precise control over the synthesis process. It is particularly valuable in constructing peptides with glutamic acid residues, as it prevents unwanted side reactions and maintains the integrity of the peptide sequence. Additionally, it is employed in the development of peptide-based drugs, biomaterials, and research tools, where high purity and specificity are essential.