Crystal structure of 2-hy-droxy-3-(prop-2-yn-1-yl)naphthalene-1,4-dione.

The naphtho-quinone unit of the title compound, CHO, is essentially planar, with an r.m.s. deviation of 0.013 Å for the non-H atoms. The essentially linear propargyl group is tilted by 113° relative to the naphtho-quinone plane. In the crystal, mol-ecules are linked a pair of O-H⋯O hydrogen bonds, forming an inversion dimer. The dimers are further linked pairs of C-H⋯O hydrogen bonds into a tape structure along [20]. No π-π stacking is observed in the present case as it could be expected for naphtho-quinone derivatives.