Ethyl 5-hydroxy-6-oxo-4-phenyl-5,6-dihydro-4H-cyclopenta[b]thiophene-5-carboxylate

In the title molecule, C16H14O4S, the dihydrocyclopentathiophenone ring system is almost planar, with an r.m.s. deviation of 0.060 angstrom from the best fit plane through all nine non-H atoms. The cyclopentanone ring adopts a severely flattened envelope conformation with the C atom carrying the OH and ethylcarboxylate substituents at the flap. This atom lies only 0.185 (3) angstrom from the plane through the other four C atoms. The phenyl substituent is inclined at 43.37 (5)degrees to the dihydrocyclopentathiophenone mean plane. In the crystal, molecules are linked by pairs of O-H center dot center dot center dot O hydrogen bonds, forming inversion dimers with R-2(2)(10) ring motifs. Weak C-H center dot center dot center dot O hydrogen bonds also link molecules into chains along c, while an approximately orthogonal set of C-H center dot center dot center dot O contacts form chains along b, resulting in layers lying parallel to (100). Inversion dimers also form through weaker R-2(2)(12) C-H center dot center dot center dot S contacts, which combine with C-H center dot center dot center dot O contacts to form stacks along b.