This compound is widely used in bioconjugation and chemical biology due to its PEG (polyethylene glycol) spacer, which enhances solubility and reduces immunogenicity. It is commonly employed in the modification of peptides, proteins, and other biomolecules to improve their pharmacokinetic properties. The t-butyl ester group provides a protective moiety that can be easily deprotected under mild acidic conditions, allowing for further functionalization. Its application is particularly valuable in drug delivery systems, where it helps in creating stable and targeted therapeutic agents. Additionally, it is utilized in the development of linkers for antibody-drug conjugates (ADCs), enabling precise delivery of cytotoxic agents to cancer cells.