Crystal structure of (1S,3R,8R,9R)-2,2-di-chloro-3,7,7-tri-methyl-10-methylenetri-cyclo-[6.4.0.0(1,3)]dodecan-9-ol.

The title compound, C16H24Cl2O, was synthesized by treating (1S,3R,8S,9R,10S)-2,2-di-chloro-3,7,7,10-tetra-methyl-9,10-ep-oxy-tri-cyclo-[6.4.0.0(1,3)]dodecane with a concentrated solution of hydro-bromic acid. It is built up from three fused rings: a cyclo-heptane ring, a cyclo-hexyl ring bearing alkene and hy-droxy substituents, and a cyclo-propane ring bearing two chlorine atoms. The asymmetric unit contains two mol-ecules linked by an O-H⋯O hydrogen bond. In the crystal, further O-H⋯O hydrogen bonds build up an R 4 (4)(8) cyclic tetra-mer. One of the mol-ecules presents disorder that affects the seven-membered ring. In both mol-ecules, the six-membered rings display a chair conformation, whereas the seven-membered rings display conformations inter-mediate between boat and twist-boat for the non-disordered mol-ecule and either a chair or boat and twist-boat for the disordered mol-ecule owing to the disorder. The absolute configuration for both mol-ecules is 1S,3R,8R,9R and was deduced from the chemical pathway and further confirmed by the X-ray structural analysis.