(-)-3,7-Dioxo-5beta-cholanic acid: dual hydrogen-bonding modes in a diketonic bile-acid derivative.

The asymmetric unit of the title compound, C(24)H(36)O(4), contains three molecules, all differing in their side-chain conformations and all linked by hydrogen bonding confined entirely within a three-molecule block. One connection is of the acid-to-ketone type [O...O = 2.7055 (19) Angstrom and O-H...O = 180 degrees ] and the other involves carboxyl pairing [O...O = 2.6485 (18) and 2.6598 (18) Angstrom, and O-H...O = 168 and 174 degrees ]. Numerous intermolecular C-H...O close contacts connect neighbouring molecules.