Abstract
In the title compound, C(12)H(10)O(4), the five-membered ring adopts an envelope conformation, with the Csp(3) atom at the flap [deviation = 0.145 (2) angstrom]. In the crystal structure, molecules are linked by intermolecular O-H center dot center dot center dot O and C-H center dot center dot center dot O hydrogen bonds, forming a three-dimensional network.