Organic/Medicinal chemistry plays a vital role in drug discovery and development. Synthetic organic chemistry is a powerful tool to create medicinally useful molecules by rational structure-based drug discovery approach. Innovative methodologies are greatly needed to overcome synthetic challenges and produce biologically active molecules efficiently. This book describes such novel and practical methods: (i) the development of new methodologies for the asymmetric synthesis of homotropinone and tropane alkaloids such as cocaine using enantiopure sulfinimines; and (ii) Stereoselective synthesis of conformationally constrained novel proline analogs (methanoprolines) and pyrrolidine analogs (methanopyrrolidines) including their biological applications. This research work is highly significant to scholars working in the fields of Organic, Medicinal, and Pharmaceutical Chemistry.