(1S,3R,8R)-2,2-Dibromo-3,7,7,10-tetra-methyltricyclo-[6.4.0.0(1,3)]dodec-9-en-11-one

Acta Crystallogr Sect E Struct Rep Online. 2012 Dec 1;68(Pt 12):o3341-2. doi: 10.1107/S1600536812046089. Epub 2012 Nov 14.

Abstract

The title compound, C16H22Br2O, was synthesized from β-himachalene (3,5,5,9-tetra-methyl-2,4a,5,6,7,8-hexa-hydro-1H-benzocyclo-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 additional three-membered ring from the reaction of himachalene with dibromo-carbene. The six-membered ring has an envelope conformation, with the C atom belonging to the three-membered ring forming the flap, whereas the seven-membered ring displays a screw-boat conformation; the dihedral angle between the rings (all atoms) is 60.92 (16)°.