Structure of WF-3681, 3-(2,5-dihydro-4-hydroxy-5-oxo-3-phenyl-2-furyl)propionic acid.

C13H12O5, Mr = 248.24, monoclinic, C2/c, a = 18.757 (8), b = 7.282 (2), c = 17.511 (8) A, beta = 91.20 (3) degrees, V = 2391 (3) A3, Z = 8, Dx = 1.379 Mg m-3, lambda(Cu K alpha) = 1.54178 A, mu = 0.859 mm-1, F(000) = 1040, T = 293 K. Final R = 0.054 for 1409 unique observed reflections. The molecule contains two planar regions which differ in orientation by 5.7 degrees. Distances from the carbonyl carbons to the center of the phenyl ring are not in the range found in the crystal structures of other potent aldose reductase inhibitor molecules.