Used extensively in peptide synthesis as a protecting group for glutamic acid. The Fmoc group safeguards the amino group during the coupling process, while the OtBu group protects the carboxylic acid side chain. This allows for selective deprotection and synthesis of complex peptides. Commonly applied in solid-phase peptide synthesis (SPPS) for producing peptides with high purity and specificity. Its stability under basic conditions makes it ideal for stepwise peptide assembly. Widely utilized in pharmaceutical research, particularly in the development of therapeutic peptides and protein-based drugs. Also employed in the study of protein-protein interactions and enzyme activity. Its versatility and reliability make it a staple in organic and medicinal chemistry laboratories.