Used as an intermediate in the synthesis of pharmaceutical compounds, particularly in the development of active pharmaceutical ingredients (APIs) requiring pyrrolidine ring structures. Its chlorosulfonyl and carbobenzyloxy (Cbz) protecting group functionalities allow for selective reactions in multi-step organic syntheses. Commonly employed in the preparation of protease inhibitors and other bioactive molecules where controlled functionalization of nitrogen-containing heterocycles is required. Suitable for use in peptide chemistry and medicinal chemistry research due to its ability to introduce modified pyrrolidine moieties into complex molecules.