General approach for the stereocontrolled construction of the beta-lactam ring in amino acid-derived 4-alkyl-4-carboxy-2-azetidinones

Research has been conducted on the 4-alkyl-4-carboxy-2-azetidinones. The asymmetric synthesis of these compounds derived from amino acids has been carried out and the results indicate that the beta-lactam ring construction has been produced via the N (super)alpha -chloroacetyl derivative's intramolecular cyclization.