Used in peptide synthesis as a protected intermediate, particularly in the preparation of structurally complex peptides where the thiazolidine ring acts as a proline mimic. The Boc group provides temporary protection of the amine functionality, allowing selective coupling reactions in solid-phase or solution-phase synthesis. It is valuable in medicinal chemistry for developing peptidomimetics and enzyme inhibitors, especially in research targeting proteases and other conformationally sensitive biological targets. Its cyclic structure helps enforce specific backbone conformations, improving metabolic stability and bioavailability in drug design.