Ethyl (2E)-2-(2H-1,3-benzodioxol-5-yl-methyl-idene)-4-chloro-3-oxobutano-ate.

In the title compound, C(14)H(13)ClO(5), the five-membered ring is in an envelope conformation with the methyl-ene C-atom being the flap. The conformation about the C=C double bond [1.341 (2) Å] is E. The chloro-propan-2-one residue is approximately orthogonal to the remaining mol-ecule [dihedral angle = 88.03 (6)°]. In the crystal, the mol-ecules associate via C-H⋯O inter-actions, involving both carbonyl-O atoms, giving rise to an undulating two-dimensional array in the ac plane.