Structure of (R)-tetrahydro-2-furancarboxylic acid monohydrate.

C5H10O4, Mr = 134.31, monoclinic, P2(1), a = 11.670 (2), b = 6.177 (3), c = 10.704 (2) A, beta = 115.11 (2) degrees, V = 698.7 (4) A3, Z = 4, Dm = 1.26, Dx = 1.28 g cm-3, Cu K alpha, lambda = 1.54178 A, mu = 9.69 cm-1, F(000) = 288, room temperature, R = 0.046 for 1047 reflections with [Fo[ greater than 3 sigma(F). There are two independent molecules of the title compound in the crystal. No twofold symmetry is observed in the tetrahydrofuran rings. Hydrogen bonds between water molecules and carboxylic acid groups stabilize the crystal structure.