Structure of 6-(3,3-dimethyl-2-oxo-2,3-dihydro-5-furanyl)-2-pyridone at 145 K.

C11H11NO3, M(r) = 205.21, triclinic, P1, a = 5.725 (1), b = 9.038 (1), c = 10.401 (2) A, alpha = 101.37 (1), beta = 102.63 (1), gamma = 102.83 (1) degrees, V = 494.7 (3) A3, Z = 2, Dx = 1.38 g cm-3, lambda (Mo K alpha) = 1.7107 A, mu = 0.62 cm-1, F(000) = 216, T = 145 K, R = 0.049, wR = 0.063 for 2386 unique observed reflections. The molecules, which are self-associating in solution, are arranged in the crystal in centrosymmetric dimers joined by N--H...O bonds between the amide functional groups. Analysis of displacement parameters indicates that the furanyl and pyridone groups are independently quite rigid, with the furanyl group librating with respect to the hydrogen-bonded pyridone.