α-Azetidinones is the key intermediate of the penems antibiotics. The utility of azetidinones as synthons for various biologically active compounds has promoted to study of its synthetic methods. The progress of asymmetric synthesis of azetidinones is reviewed, and the methods for the preparation of azetidinones are discussed in detail.

Key words: α-azetidinone, penems nucleus, β-lactam, asymmetric synthesis