(1S,3R,8R,9S,11R)-2,2,10,10-Tetra- chloro-3,7,7,11-tetramethyltetracyclo- [6.5.0.0 1,3 .0 9,11 ]tridecane Najia Ourhriss, a * Ahmed Benharref, a Mohamed Saadi, b Lahcen El Ammari b and Moha Berraho a a Laboratoire de Chimie Biomole ´culaire, Substances Naturelles et Re ´activite ´ "Unite ´ Associe ´e au CNRST(URAC16)", Faculte ´ des Sciences Semlalia, BP 2390, Bd My Abdellah, 40000 Marrakech, Morocco, and b Laboratoire de Chimie du Solide Applique ´e, Faculte ´ des Sciences, Avenue Ibn Battouta, BP 1014 Rabat, Morocco Correspondence e-mail: berraho@uca.ma Received 14 January 2013; accepted 16 January 2013 Key indicators: single-crystal X-ray study; T = 296 K; mean (C–C) = 0.002 A ˚ ; R factor = 0.032; wR factor = 0.085; data-to-parameter ratio = 28.5. The title compound, C 17 H 24 Cl 4 , was synthesized from - himachalene (3,5,5,9-tetramethyl-2,4a,5,6,7,8-hexahydro-1H- benzocycloheptene), which was isolated from the essential oil of the Atlas cedar (Cedrus Atlantica). The molecule is built up from fused six- and seven-membered rings and two three- membered rings from the reaction of -himachalene with dichlorocarbene. The six-membered ring shows a chair conformation, whereas the seven-membered ring displays a boat conformation. Related literature For the isolation of -himachalene, see: Joseph & Dev (1968); Plattier & Teisseire (1974). For the reactivity of this sesqui- terpene, see: Lassaba et al. (1998); Chekroun et al. (2000); El Jamili et al. (2002); Sbai et al. (2002); Dakir et al. (2004). For its biological activity, see: Daoubi et al. (2004). For puckering parameters, see: Cremer & Pople (1975). Experimental Crystal data C 17 H 24 Cl 4 M r = 370.16 Monoclinic, P2 1 a = 8.8807 (6) A ˚ b = 11.6280 (8) A ˚ c = 9.0596 (6) A ˚  = 107.665 (2)  V = 891.42 (10) A ˚ 3 Z =2 Mo K radiation  = 0.66 mm 1 T = 296 K 0.41  0.35  0.27 mm Data collection Bruker X8 APEX diffractometer 15112 measured reflections 5419 independent reflections 4910 reflections with I >2(I) R int = 0.019 Refinement R[F 2 >2(F 2 )] = 0.032 wR(F 2 ) = 0.085 S = 1.03 5419 reflections 190 parameters 1 restraint H-atom parameters constrained Á max = 0.32 e A ˚ 3 Á min = 0.19 e A ˚ 3 Absolute structure: Flack (1983) Flack parameter: 0.04 (4) Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: PLATON (Spek, 2009) and publCIF (Westrip, 2010). Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: BT6883). References Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Chekroun, A., Jarid, A., Benharref, A. & Boutalib, A. (2000). J. Org. Chem. 65, 4431–4434. Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354–1358. Dakir, M., Auhmani, A., Ait Itto, M. Y., Mazoir, N., Akssira, M., Pierrot, M. & Benharref, A. (2004). Synth. Commun. 34, 2001–2008. Daoubi, M., Duran -Patron, R., Hmamouchi, M., Hernandez -Galan, R., Benharref, A. & Isidro, G. C. (2004). Pest Manag. Sci. 60, 927–932. El Jamili, H., Auhmani, A., Dakir, M., Lassaba, E., Benharref, A., Pierrot, M., Chiaroni, A. & Riche, C. (2002). Tetrahedron Lett. 43, 6645–6648. Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854. Flack, H. D. (1983). Acta Cryst. A39, 876–881. Joseph, T. C. & Dev, S. (1968). Tetrahedron, 24, 3841–3859. Lassaba, E., Eljamili, H., Chekroun, A., Benharref, A., Chiaroni, A., Riche, C. & Lavergne, J.-P. (1998). Synth. Commun. 28, 2641–2651. Plattier, M. & Teisseire, P. (1974). Recherche, 19, 131–144. Sbai, F., Dakir, M., Auhmani, A., El Jamili, H., Akssira, M., Benharref, A., Kenz, A. & Pierrot, M. (2002). Acta Cryst. C58, o518–o520. Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Spek, A. L. (2009). Acta Cryst. D65, 148–155. Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. organic compounds Acta Cryst. (2013). E69, o275 doi:10.1107/S1600536813001700 Ourhriss et al. o275 Acta Crystallographica Section E Structure Reports Online ISSN 1600-5368