Fmoc-L-Cyclopropylglycine is widely used in peptide synthesis as a building block. Its Fmoc (9-fluorenylmethoxycarbonyl) protecting group is particularly valuable in solid-phase peptide synthesis (SPPS), allowing for the stepwise assembly of peptides. The cyclopropyl group in its structure introduces conformational rigidity, which can be beneficial in designing peptides with specific secondary structures or enhanced stability. This compound is often employed in the development of peptide-based drugs, where the cyclopropyl moiety can improve bioavailability and metabolic stability. Additionally, it is utilized in research to study the effects of constrained amino acids on peptide folding and interactions with biological targets. Its application extends to the synthesis of peptidomimetics, which are designed to mimic natural peptides while offering improved pharmacological properties.