Used primarily in solid-phase peptide synthesis as a linker molecule to attach amino acids to polyethylene glycol (PEG)-based resins. Its structure allows for the incorporation of a cleavable ester bond that can be selectively broken under mild acidic or basic conditions, enabling controlled release of the synthesized peptide from the support matrix. The Fmoc group provides temporary protection of the amine functionality, allowing stepwise assembly of peptides using standard Fmoc chemistry. This compound is especially useful in the preparation of peptide arrays and in combinatorial chemistry where PEGylated supports are employed to enhance solvation and coupling efficiency.