5-Chloro-6-hydroxy-7,8-dimethylchroman-2-one

In the title molecule, C11H11ClO3, the fused pyran ring adopts a half-chair conformation. In the crystal, intermolecular O-H center dot center dot center dot O hydrogen bonds link molecules into chains along [100]. These chains are interconnected by weak intermolecular C-H center dot center dot center dot O contacts which generate R-2(2)(8) ring motifs, forming sheets parallel to (001). Tetragonal symmetry generates an equivalent motif along b. Furthermore, the sheets are linked along the c axis by offset pi-pi stacking interactions involving the benzene rings of adjacent molecules [with centroidcentroid distances of 3.839 (2) angstrom], together with an additional weak C-H center dot center dot center dot O hydrogen bond, resulting in an overall three-dimensional network.