phenyldiazomethane

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

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

4-(2,2-bis(methylthio)ethyl)-2-azetidinone

dibenzyl ketomalonate