Used as an intermediate in the synthesis of pharmaceutical compounds, particularly in the development of protease inhibitors and other biologically active molecules. The BOC-protected azetidine ring provides structural stability and selectivity during multi-step reactions, while the sulfonyl ester moiety allows for further functionalization. Commonly employed in medicinal chemistry for constructing constrained small-ring systems that enhance metabolic stability and binding affinity in drug candidates. Suitable for solid-phase and solution-phase peptide-like synthesis where controlled reactivity is required.