Аннотация: Circular dichroism (CD) spectra were taken for 13 2-azetidinones with one, two, and three asymmetric sites. A possible correlation was found between the sign of the Cotton effect (CE) of the n-pi* transition of the amide chromophore with the absolute configuration of the endocyclic stereocenters of 3-methyl-, 4-methyl-, and 3,4-dimethyl-2-azetidinones both with and without an achiral N-alpa,alpa-dimethylbenzyl or chiral N-alpha-methylbenzyl substituent.