Used in peptide synthesis as a protecting group for glutamic acid. The Fmoc group ensures selective deprotection during solid-phase peptide synthesis, enabling the construction of complex peptides. It is particularly valuable in synthesizing peptides for pharmaceutical research, where precise amino acid sequences are critical. The tert-butyl ester (OtBu) protects the carboxylic acid side chain, preventing unwanted reactions. This compound is essential in producing peptides for drug development, biochemical studies, and therapeutic applications. Its stability and ease of removal make it a preferred choice in modern peptide chemistry.