diethyl 2-[4-(2-ethoxy-2-oxoethyl)-4-hydroxy-3-phenyl-1,3-thiazolidin-2-ylidene]propanedioate

N,N'-bis(2-hydroxyphenyl)propanediamide

diethyl 2,2-bis(methylsulfanyl)propanedioate

diethyl 2-thiophen-2-ylpropanedioate

diethyl 2-methylsulfonyloxypropanedioate