Crystal and molecular structures of 11-hydroxy-7-oxodrim-8(9)-ene

The crystal structure of 11-hydroxy-7-oxodrim-8(9)-ene is determined. The c rystals are monoclinic. The unit cell parameters are a = 16.716(4) Angstrom , b = 11.052(3) Angstrom, c = 7.542(3) Angstrom, gamma = 76.11 degrees, Z = 4, mu = 1.476 cm(-1), rho(calcd) = 1.147 g/cm(3), and space group P2(1). T he structure is solved by the direct method and refined by the least-square s procedure to R = 0.045. There are two molecules of 11-hydroxy-7-oxodrim-8 (9)-ene in the asymmetric unit. Both molecules have the same conformation o f the skeleton and can be described as rotomers differing in orientation of the OH groups with respect to the skeleton. In both molecules, the cyclohe xane rings have a usual chair conformation. In the crystal, two independent molecules are linked by a hydrogen bond. The molecular pairs related by th e twofold screw axes are linked by hydrogen bends into helices running alon g the z-axis of the crystal. The helices are bound through van der Waals in teractions. (C) 2000 MAIK "Nauka/Interperiodica".