Crystal structure of 14-deoxyandrographolide

The title compound, 14-deoxyandrographolide (C20H30O4), a diterpenoid, crystallizes in the monoclinic space group P2(1) with unit cell parameters a = 6.719(3), b = 6.971(2) c = 19.329(2)Angstrom, beta = 93.20(2)degrees. The structure has been solved by direct methods and refined to a residual index R = 0.084. The six-membered rings are trans-fused and both are in the chair conformation. The furan ring is planar. Molecules are held together by C-H...O and O-H...O hydrogen bonds.