(1S,2S,4R)-3,3-Dichloro-4,8,12,12-tetra­methyl­tricyclo­[5.5.0.02,4]dodeca-6,8-diene

Ahmed Benharref; Lahcen El Ammari; Moha Berraho; Esaadia Lassaba

doi:10.1107/S1600536810034070

. 2010 Aug 28;66(Pt 9):o2463. doi: 10.1107/S1600536810034070

(1S,2S,4R)-3,3-Dichloro-4,8,12,12-tetramethyltricyclo[5.5.0.0^2,4]dodeca-6,8-diene

Ahmed Benharref ^a,^*, Lahcen El Ammari ^b, Moha Berraho ^a, Esaadia Lassaba ^a

PMCID: PMC3007900 PMID: 21588782

Abstract

The title compound, C₁₆H₂₂Cl₂, a derivative of β-himachalene, was semi-synthesized from natural essential oils of Cedrus atlantica. The molecule is built up from two fused six- and seven-membered rings. The six-membered ring has a perfect chair conformation, whereas the seven-membered ring displays a screw boat conformation; the dihedral angle between the rings is 46.48 (9)°.

Related literature

For background to himachalene derivatives, see: Plattier & Teiseire (1974 ▶); Sbai et al. (2002 ▶). For ring puckering analysis, see: Cremer & Pople (1975 ▶). For the synthesis of the title compound, see: Lassaba et al. (1997 ▶). For the reactivity of this sesquiterpene, see: El Jamili et al. (2002 ▶; Sbai et al. (2002 ▶). For the olfactive properties of β-himachalene, see: Benharref et al. (1991 ▶); Bisarya & Dev (1968 ▶); Chekroun et al. (2000 ▶). graphic file with name e-66-o2463-scheme1.jpg

Experimental

Crystal data

C₁₆H₂₂Cl₂
M _r = 285.24
Orthorhombic,
a = 7.4356 (17) Å
b = 8.3124 (18) Å
c = 24.108 (6) Å
V = 1490.1 (6) Å³
Z = 4
Mo Kα radiation
μ = 0.42 mm⁻¹
T = 298 K
0.27 × 0.18 × 0.12 mm

Data collection

Bruker X8 APEXII CCD area-detector diffractometer
10992 measured reflections
3691 independent reflections
3282 reflections with I > 2σ(I)
R _int = 0.026

Refinement

R[F ² > 2σ(F ²)] = 0.032
wR(F ²) = 0.096
S = 1.11
3691 reflections
175 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.34 e Å⁻³
Δρ_min = −0.29 e Å⁻³
Absolute structure: Flack (1985 ▶), 1535 Friedel pairs
Flack parameter: −0.06 (6)

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT-Plus (Bruker, 2009 ▶); data reduction: SAINT-Plus; 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, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810034070/er2079sup1.cif

e-66-o2463-sup1.cif^{(16.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810034070/er2079Isup2.hkl

e-66-o2463-Isup2.hkl^{(177.3KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

The authors thank the Unit of Support for Technical and Scientific Research (UATRS, CNRST) for the X-ray measurements.

supplementary crystallographic information

Comment

Our work lies within the framework of the valorization of the most abundant essential oils in Morocco, such as Cedrus atlantica. This oil is made up mainly (75%) of bicyclic sesquiterpenes hydrocarbons, among which is found the compound, β-himachalene (Bisarya & Dev, 1968; Plattier & Teiseire, 1974). The reactivity of this sesquiterpene has been studied extensively by our team (El Jamili et al., 2002; Sbai et al., 2002) in order to prepare new products having olfactive proprieties suitable for the perfume or cosmetics industry. Thus, the action of one equivalent of meta-chloroperbenzoïc acide (m-CPBA) on, β- himachalène gives in quantitative yields the monoepoxyde (Benharref et al., 1991; Chekroun et al., 2000). The treatement of this monoepoxyde with dichlorocarbene, generated in situ from chloroform and in the presence of sodium hydroxide as base and n-benzyltriethylammonium chloride as catalyst, give a mixtrure of two diastereoisomers: (1S,2R,7S,8S,10R) -9,9-dichloro-1,2- epoxy-2,6,6,10-tetramethyl-tricyclo[5,5,0,08,10]dodecane and (1S,2R,7S,8R,10S) -9,9-dichloro-1,2-epoxy-2,6,6,10-tetramethyl- tricyclo[5,5,0,0^8,10] dodecane (Lassaba et al., 1997). Also in order to prepare products with high added value, we have treated the isomer (1S,2R,7S,8S,10R) -9,9-dichloro-1,2- epoxy-2,6,6,10-tetramethyl-tricyclo[5,5,0,0^8,10] dodecane (I) by hydrochloric acid gas and we got one sesquiterpene dichloro-hydrocarbure (II) in yield 75%. The molecule is built up from two fused six-and seven-membered rings(Fig.1). The six-membered ring has a perfect chair conformation, with as indicated by the total puckering amplitude QT = 0.2385 (2)Å and spherical polar angle θ= 99.60 (2)° with φ -117.07 (2)°, whereas the seven-membered ring display a screw boat conformation with QT = 0.9566 (2) Å, θ = 68.84 (2)°, φ2 = -112.42 (1)° and φ3 = 142.26 (3)° (Cremer & Pople, 1975). Owing to the presence of the Cl atoms, the absolute configuration could be fully confirmed to be C7(S), C8(S) and C10(R) (Flack & Bernardinelli, 2000).

Experimental

100 mg (0,33 mm l) of the isomer, (1S,2R,7S,8S,10R)-9,9-dichloro- 1,2-epoxy-2,6,6,10- tetramethyl-tricyclo[5,5,0,08,10]dodecane, dissolved in 20 ml of dichloromethane and then treated with a stream of gaseous hydrochloric acid at 0° for 5 minutes. After concentration of solvent, the residue obtained was chromatgraphed on silica gel impregnated with silver nitrate (10%) with hexane as eluent.