1,4-diphenylbutane-1,2,4-trione

2-bromo-1,4-diphenyl-2-butene-1,4-dione

2,3-dibromo-1,4-diphenyl-but-2-ene-1,4-dione

optically inactive 2-acetoxy-3-chloro-1,4-diphenyl-butane-1,4-dione

2-chloro-1,4-diphenyl-but-2-ene-1,4-dione