tert-Butyl ((1R,3S)-3-aminocyclopentyl)carbamate hydrochloride is used as a key intermediate in the synthesis of pharmaceuticals, particularly in the development of antiviral and central nervous system agents. This chiral compound features a cyclopentyl backbone with a Boc-protected amine at one position and a free amino group as the hydrochloride salt at the 3-position, making it valuable in asymmetric synthesis and drug design where stereochemistry plays a critical role in biological activity. Commonly employed in the preparation of protease inhibitors and receptor modulators due to its structural rigidity and ability to enhance metabolic stability in final drug compounds.