(1S,3S,8R,9S,11R)-10,10-Di-bromo-3,7,7,11-tetra-methyl-tetra-cyclo-[6.5.0.0(1,3).0(9,11)]trideca-ne.

The title compound, C17H26Br2, was synthesized from ß-himachalene (3,5,5,9-tetra-methyl-2,4a,5,6,7,8-hexa-hydro-1H-benzo-cyclo-heptene), which was isolated from the essential oil of the Atlas cedar (Cedrus Atlantica). The asymmetric unit contains two independent mol-ecules with similar conformations. Each mol-ecule is built up from fused six- and seven-membered rings and two appended three-membered rings. In both mol-ecules, the six-membered ring has a screw boat conformation, whereas the seven-membered ring displays a boat conformation. No specific inter-molecular inter-actions were discerned in the crystal packing.

(1S,3R,8R,11S)-11-Bromo-10-bromo-methyl-2,2-di-chloro-3,7,7-tri-methyl-tricyclo-[6.4.0.0(1,3)]dodec-9-ene.

The title compound, C16H22Br2Cl2, was synthesized from ß-him-achalene (3,5,5,9-tetra-methyl-2,4a,5,6,7,8-hexa-hydro-1H-benzo-cyclo-heptene), which was isolated from the essential oil of the Atlas cedar (Cedrus Atlantica). The mol-ecule is built up from fused six- and seven-membered rings and an appended three-membered ring. The six-membered ring has a half-chair conformation, whereas the seven-membered ring displays a chair conformation. The dihedral angle between the two best plane through each ring is 59.5 (2)°. No specific inter-molecular inter-actions were discerned in the crystal packing.

(1S,3S,8R,10R,11R)-3,7,7,10-Tetra-methyl-tri-cyclo-[6.4.0.0(1,3)]dodecan-11-ol.

The title compound, C16H28O, was synthesized by three steps from ß-himachalene (3,5,5,9-tetra-methyl-2,4a,5,6,7,8-hexa-hydro-1H-benzo-cyclo-heptene), which was isolated from the essential oil of the Atlas cedar (Cedrus atlantica). The mol-ecule is built up from fused six- and seven-membered rings and an appended three-membered ring. The six-membered ring has twist-boat conformation, whereas the seven-membered ring displays a chair conformation. In the crystal, mol-ecules are linked into chains propagating along the a-axis direction by O-H⋯O hydrogen bonds.

(1S,2R,7R,8S,10R)-9,9-Di-bromo-2,6,6,10-tetra-methyl-1α,2α-ep-oxy-tri-cyclo-[5.5.0.0(8,10)]dodeca-ne.

The title compound, C16H24Br2O, was synthesized from the reaction of ß-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) essential oil, after reaction with di-bromo-carbene. The asymmetric unit contains two independent mol-ecules with similar conformations. Each mol-ecule is built up from fused six-and seven-membered rings and two three-membered rings. In both mol-ecules, the six-membered ring has an envelope conformation with the flap provided by the C atom of the ep-oxy ring, whereas the seven-membered ring displays a chair conformation. The crystal packing is governed only by van der Waals inter-actions. The absolute configuration was established from anomalous dispersion effects.

(1R,4R,6S,7S)-5,5-Di-chloro-1,4,8,8-tetra-methyl-tri-cyclo-[5.4.1(1,7).0(4,6)]dodecan-12-one.

The title compound, C16H24Cl2O, was synthesized in three steps from ß-himachalene (3,5,5,9-tetra-methyl-2,4a,5,6,7,8-hexa-hydro-1H-benzo-cyclo-heptene), which was isolated from essential oil of the 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 arising from the reaction of himachalene with di-chloro-carbene. The dihedral angles between the mean planes of the two seven-membered rings are 75.03 (9) and 75.02 (9)° in the two independent mol-ecules.