Redetermination of 3-[(Z)-1-hydr­oxy-3-oxobuten­yl]-2H-chromen-2-one at 193 K

The structure of the title compound, C₁₃H₁₀O₄, which was synthesized by the reaction of salicylaldehyde and 4-hydr­oxy-6-meth­yl-2H-pyran-2-one in the presence of triethyl­benzyl­ammonium chloride in aqueous media, was previously determined at room temperature [March, Moreno-Manas, Roca, Germain, Piniella & Dideberg (1986). J. Heterocycl. Chem. 23, 1511–1153]. As in the present determination, the X-ray analysis revealed that the title compound is in the enol form, which was confirmed by ¹H NMR data. Weak inter­molecular C—H...O inter­actions connect mol­ecules into a two-dimensional framework.