(3E,5E)-3,5-Bis(4-hy-droxy-benzyl-idene)oxan-4-one.

In the title compound, C(19)H(16)O(4), there are two 4-hy-droxy-benzyl substituents on the oxan-4-one (tetra-hydro-pyran-4-one) ring, which exhibits an envelope conformation. The dihedral angles between pyran-one ring and the two benzene rings are 26.69 (9) and 36.01 (9)° while the benzene rings make a dihedral angle of 20.88 (10)°. In the crystal, mol-ecules are linked by inter-molecular O-H⋯O hydrogen bonds into a supra-molecular three-dimensional twofold inter-penetrating hydrogen-bonded network.