Used in peptide synthesis as a protected form of glutamic acid, enabling the controlled addition of glutamic acid residues without unwanted side reactions. The benzyl ester groups protect the carboxyl functionalities, while the tosylate counterion aids in solubility and stability during reactions. Commonly applied in solid-phase peptide synthesis to build complex peptides for research in biochemistry, pharmaceuticals, and drug development. Its protective groups can be selectively removed under specific conditions, allowing for precise peptide chain elongation.