Thanks to the availability of chiral pyrrolidines from the natural chiral pool, a variety of substituted derivativatives have been commercialized and they have been successfully applied in a variety of fields, from the synthesis of stereospecific oligonucleotides - WO2018EP54056 (Hoffmann LaRoche) to the development of novel anticancer chemotherapics -WO2019020559 (Sanofi) to the treatment of autoimmune diseases - US-20190038628 (Novartis). Similarly, oxazolidines having a chiral centre on the ring have proven useful in the Medicinal Chemistry research, with applications in the always actual field of anticancers - WO2018109204 (Hoffmann LaRoche). We now have significantly improved the scope of offered Heterocyclic Compounds with a chiral unit on the main ring, including also tetrahydrofuranes.