(1R,4R,6S,7R)-5,5-Di-bromo-1,4,8,8-tetra-methyl-tri-cyclo-[5.4.1.0(4,6)]dodecan-12-one.

The title compound, C16H24Br2O, was synthesized from the reaction of β-himachalene (3,5,5,9-tetra-methyl-2,4a,5,6,7,8-hexa-hydro-1H-benzo-cyclo-heptene), which was isolated from Atlas cedar (Cedrus atlantica). The asymmetric unit contains two independent mol-ecules with similar conformations. Each mol-ecule is built up from two fused seven-membered rings and an additional three-membered ring. In both mol-ecules, one of the seven-membered rings has a chair conformation, whereas the other displays a screw-boat conformation.