Fmoc-S-acetamidomethyl-L-penicillamine is primarily used in peptide synthesis, particularly in solid-phase peptide synthesis (SPPS). It serves as a protected form of L-penicillamine, ensuring the thiol group remains stable during the synthesis process. This compound is valuable in creating peptides with specific structural or functional properties, often in pharmaceutical research for developing therapeutic peptides. Its Fmoc group is easily removed under mild conditions, making it a versatile choice for synthesizing complex peptides with high precision. Additionally, it is employed in studies involving cysteine-rich peptides or proteins, where controlled protection and deprotection of thiol groups are critical.