Synthesis of Carbocyclic and Heterocyclic β-Aminocarboxylic Acids

In consequence of their biological e ff ects, conformationally constrained carbocyclic β -amino acids have generated great interest among synthetic and medicinal chemists in the past 2 decades, and they have become a hot topic in organic and bioorganic chemistry. These compounds are found in natural products and antibiotics. They are also considered important precursors for pharmacologically interesting β -lactams and other bioactive compounds. Certain carbocyclic β -amino acids, e.g., cispentacin , icofungipen , and BAY Y9379 , possess noteworthy antifungal or antibacterial activities, while tilidin , a phenyl-substituted cyclohexene amino ester, is an analgetic.