Crystal structure of spirodienone II

Abstract

The crystal structure of the title compound has been determined by a three-dimensional X-ray analysis. The crystals are orthorhombic, with a= 9·781 ± 0·003, b= 9·923 ± 0·003, c= 9·428 ± 0·003 Å, and Z= 4, in space group P2₁2₁2₁. The structure was solved from diffractometer data by the phase-addition and tangent refinement procedures and refined by full-matrix least-squares calculations to a final R of 0·055 for 878 independent observed reflections. The molecule consists of a cyclodienone ring and a cyclohexane ring, joined through a spiro-carbon atom: it contains an almost perfect mirror plane. The mean of the angles around the spiro-carbon atom is ca. 109·4°.