Used primarily in peptide synthesis as a protecting group for glutamic acid. It helps in preventing unwanted side reactions during the formation of peptide bonds. The tert-butyl ester group provides stability under acidic conditions, allowing selective deprotection when needed. Commonly employed in the production of complex peptides for pharmaceutical research, particularly in the development of therapeutic agents and bioactive peptides. Its application ensures precise control over the peptide assembly process, enhancing yield and purity.