9-Hydroxy-4-methyl-8-phenylthio-7,8,9,10 tetrahydrobenzo[h]coumarin

The title molecule, C20H18O3S, exists as an enantiomeric pair, the two halv es of which are linked by mutual O-H ... O hydrogen bonds involving the hyd roxyl group and the carbonyl O atom. The tetrahydrobenzene ring adopts a ha lf-chair conformation in one of the enantiomers, while in the other, it is in a conformation intermediate between sofa and half-chair. The coumarin mo ieties of the molecules are stacked along the a direction, with significant pi-pi interactions.