The first general approach toward the asymmetric synthesis of 4-alkyl-4-carboxy-2-azetidinones derivedfrom amino acids is described. The stereoselective construction of the β-lactam ring was achieved through base-mediated intramolecular cyclization of the correspondingNα-chloroacetyl derivatives bearing (+)- or (−)-10-(N,N-dicyclohexylsulfamoyl)isoborneol as chiral auxiliary (ee upto 82%).