Fmoc-L-4-hydroxyproline is widely used in peptide synthesis, particularly in solid-phase peptide synthesis (SPPS). It serves as a building block for introducing the 4-hydroxyproline residue into peptides, which is crucial for stabilizing collagen-like structures and enhancing peptide stability. This compound is also employed in the development of peptidomimetics and bioactive peptides, where the hydroxyl group can participate in hydrogen bonding, influencing the peptide's conformation and interaction with biological targets. Additionally, it finds applications in the synthesis of glycopeptides and in research focused on studying post-translational modifications, such as hydroxylation, in proteins. Its compatibility with Fmoc chemistry makes it a valuable tool in organic and medicinal chemistry for designing peptides with specific structural and functional properties.