2-Azetidineacetic acid, 1-[(2,4-dimethoxyphenyl)methyl]-4-oxo-

ethyl (RS)-1-(2,4-dimethoxybenzyl)-4-oxoazetidin-2-ylacetate

(S)-phenyl (+/-)-<1-(2,4-dimethoxybenzyl)-4-oxoazetidin-2-yl>thioacetate