From theoretical calculations to the enantioselective synthesis of a 1,3,4-trisubstituted Gly-derived 2-azetidinone

Theoretical calculations on the transition states of the cyclization of 2S-chloropropionyl amino acid derivatives to the corresponding β-lactams have served to explain the high stereoselectivity of the reaction, and have been the driving force to extend the procedure to the preparation of a Gly-derived 1,3,4-trisubstituted 2-azetidinone in enantiopure form.