(1S,3R,8R)-2,2-Dichloro-3,7,7,10-tetramethyl-11-methylenetricyclo[6.4.0.01,3]dodec-9-ene

The title compound, C17H24Cl2, was synthesized in four steps from β-himachalene (3,5,5,9-tetramethyl-2,4a,5,6,7,8-hexahydro-1H-benzocycloheptene), which was isolated from an essential oil of the Atlas cedar (Cedrus atlantica). The molecule is built from fused six- and seven-membered rings, and an additional three-membered ring. The dihedral angle between the mean planes of the cyclohexene and cycloheptane rings is 58.37 (19)°. There is an intramolecular C—H...Cl hydrogen bond present involving a Cl atom and the H atom of the unique methine C atom, forming an S(5) ring motif. There are no significant intermolecular interactions present.