Fmoc-Asp(OMpe)-OH is a protected aspartic acid derivative featuring a 3-methylpentyl ester (OMpe) on the side-chain carboxyl group and a fluorenylmethyloxycarbonyl (Fmoc) group on the ж┴-amino group. This compound is primarily utilized as a building block in solid-phase peptide synthesis (SPPS), where the Fmoc group enables temporary protection during chain elongation, and the OMpe ester serves as an orthogonal protecting group for the aspartic acid side chain, preventing unwanted side reactions such as aspartimide formation. Its application is central to the synthesis of complex peptides and pharmaceutical intermediates, particularly in the development of peptide-based drugs and bioactive molecules. Additionally, it is a key reagent in biochemical research for constructing modified peptides with enhanced stability or specific functional properties.