dibenzyl 2-<1-bromo-2-(methylthio)vinyl>-4-oxo-1-azetidinemalonate

dibenzyl α-chloro-2-<2-(methylsulfinyl)-2-(methylthio)ethyl>-4-oxo-1-azetidinemalonate

dibenzyl 1-bromo-2-(methylthio)carbapenam-3,3-dicarboxylate

dibenzyl 2-<2,2-bis(methylthio)ethyl>-α-chloro-4-oxo-1-azetidinemalonate

dibenzyl 2-<2,2-bis(methylthio)ethyl>-α-hydroxy-4-oxo-1-azetidinemalonate