organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

(1S,3R,8R,11S)-11-Bromo-10-bromo­methyl-2,2-di­chloro-3,7,7-tri­methyl­tri­cyclo­[6.4.0.01,3]dodec-9-ene

aLaboratoire de Chimie des Substances Naturelles, "Unité Associé au CNRST (URAC16)", Faculté des Sciences Semlalia, BP 2390 Bd My Abdellah, 40000 Marrakech, Morocco, bLaboratoire de Chimie du Solide, Appliquée, Faculté des Sciences, Université MohammedV-Agdal , Avenue Ibn Battouta, BP 1014, Rabat, Morocco, and cLaboratoire de Chimie du Solide, Appliquée, Faculté des Sciences, Université MohammedV-Agdal, Avenue Ibn Battouta, BP 1014, Rabat, Morocco
*Correspondence e-mail: berraho@uca.ma

(Received 15 July 2013; accepted 16 July 2013; online 20 July 2013)

The title compound, C16H22Br2Cl2, was synthesized from β-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 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 inter­molecular inter­actions were discerned in the crystal packing.

Related literature

For the reactivity and biological properties of β-himachalene, see: El Haib et al. (2011[El Haib, A., Benharref, A., Parres-Maynadie, S., Manoury, E., Urrutigoıty, M. & Gouygou, M. (2011). Tetrahedron Asymmetry, 22, 101-108.]); El Jamili et al. (2002[El Jamili, H., Auhmani, A., Dakir, M., Lassaba, E., Benharref, A., Pierrot, M., Chiaroni, A. & Riche, C. (2002). Tetrahedron Lett. 43, 6645-6648.]); Daoubi et al. (2004[Daoubi, M., Duran-Patron, R., Hmamouchi, M., Hernandez-Galan, R., Benharref, A. & Isidro, G. C. (2004). Pest Manag. Sci. 60, 927-932.]). For related structures, see: Oukhrib et al. (2013[Oukhrib, A., Benharref, A., Saadi, M., Berraho, M. & El Ammari, L. (2013). Acta Cryst. E69, o521-o522.]); Ourhriss et al. (2013[Ourhriss, N., Benharref, A., Saadi, M., El Ammari, L. & Berraho, M. (2013). Acta Cryst. E69, o275.]); Benharref et al.(2013[Benharref, A., El Karroumi, J., El Ammari, L., Saadi, M. & Berraho, M. (2013). Acta Cryst. E69, o1037-o1038.]). For puckering parameters, see: Cremer & Pople (1975[Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354-1358.]).

[Scheme 1]

Experimental

Crystal data
  • C16H22Br2Cl2

  • Mr = 445.06

  • Orthorhombic, P 21 21 21

  • a = 8.2594 (7) Å

  • b = 13.0352 (11) Å

  • c = 16.6241 (13) Å

  • V = 1789.8 (3) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 4.82 mm−1

  • T = 293 K

  • 0.20 × 0.15 × 0.12 mm

Data collection
  • Bruker APEXII CCD diffractometer

  • Absorption correction: multi-scan (SHELXS97; Sheldrick,2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]) Tmin = 0.423, Tmax = 0.617

  • 10693 measured reflections

  • 3654 independent reflections

  • 3183 reflections with I > 2σ(I)

  • Rint = 0.026

Refinement
  • R[F2 > 2σ(F2)] = 0.038

  • wR(F2) = 0.102

  • S = 1.05

  • 3654 reflections

  • 184 parameters

  • H-atom parameters constrained

  • Δρmax = 0.55 e Å−3

  • Δρmin = −0.54 e Å−3

  • Absolute structure: Flack & Bernardinelli (2000[Flack, H. D. & Bernardinelli, G. (2000). J. Appl. Cryst. 33, 1143-1148.]), 614 Friedel pairs

  • Absolute structure parameter: 0.022 (13)

Data collection: APEX2 (Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]); software used to prepare material for publication: WinGX (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]).

Supporting information


Comment top

The bicyclic sesquiterpene β-himachalene is the main constituent (50%) of the essential oil of the Atlas cedar (Cedrus atlantica) (El Haib et al., 2011). The reactivity of this sesquiterpene and its derivatives has been studied extensively by our team in order to prepare new products having biological proprieties (El Jamili et al., 2002; Daoubi et al., 2004; Ourhriss et al., 2013; Oukhrib et al., 2013; Benharref et al., 2013). In this work, we present the crystal structure of the title compound, (1S,3R,8R,11S)- 10- bromomethyl-11-bromo-2,2-dichloro-3,7,7-trimethyltricyclo [6.4.0.01,3] dodec-9-ene. The molecule contains fused six-and seven-membered rings, which is fused to a three-membered ring as shown in Fig. 1. The six-membered ring has a half-chair conformation, as indicated by the total puckering amplitude QT = 0.466 (4) Å and spherical polar angle θ = 129.9 (7)° with ϕ = 152.5 (7)°, whereas the seven-membered ring displays a chair conformation with QT = 0.8129 (51) Å, θ = 32.71 (40)°, ϕ2 = -46.29 (5)° and ϕ3 = -77.86 (39)° (Cremer & Pople, 1975). Owing to the presence of Br atoms, the absolute configuration could be fully confirmed, by refining the Flack parameter (Flack & Bernardinelli, 2000) as C1(S), C3(R), C8(R) and C11(S).

Related literature top

For the reactivity and biological properties of β-himachalene, see: El Haib et al. (2011); El Jamili et al. (2002); Daoubi et al. (2004). For related structures, see: Oukhrib et al. (2013); Ourhriss et al. (2013); Benharref et al.(2013). For puckering parameters, see: Cremer & Pople (1975).

Experimental top

In a reactor equipped with a stirrer, a condenser, a dropping funnel and a thermometer containing (1S,3R,8R)-2,2-dichloro-3,7,7,10-tetramethyltricyclo [6.4.0.01,3] dodec-9-ene (2 g, 7 mmol) (El Jamili et al., 2002) and carbon tetrachloride (60 ml) was added slowly over an 1.5 h by heating and stirring a solution of bromine (1.6 g, 10 mmol) in carbon tetrachloride (5 ml). Heating and stirring were maintained for 1 h after the addition of bromine. Thereafter the reaction mixture was cooled and concentrated to evaporate the carbon tetrachloride. the residue obtained was chromatographed on silica eluting with hexane, which allowed the isolation of pure (1S,3R,8R,11S)-10-bromomethyl-11-bromo-2,2-dichloro-3,7,7-trimethyltricyclo [6.4.0.01,3] dodec-9-ene in a yield of 20% (623 mg, 1.4 mmol). The title compound was recrystallized from its hexane solution.

Refinement top

All H atoms were fixed geometrically and treated as riding with C—H = 0.96 Å (methyl), 0.97 Å (methylene), 0.98 Å (methine) with Uiso(H) = 1.2Ueq(methylene, methine) or Uiso(H) = 1.5Ueq(methyl).

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); 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: WinGX (Farrugia, 2012).

Figures top
[Figure 1] Fig. 1. Molecular structure of the title compound with the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability. level. H atoms are represented as small spheres of arbitrary radii.
(1S,3R,8R,11S)-11-Bromo-10-bromomethyl-2,2-dichloro-3,7,7-trimethyltricyclo[6.4.0.01,3]dodec-9-ene top
Crystal data top
C16H22Br2Cl2F(000) = 888
Mr = 445.06Dx = 1.652 Mg m3
Orthorhombic, P212121Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2abCell parameters from 3653 reflections
a = 8.2594 (7) Åθ = 2.8–26.4°
b = 13.0352 (11) ŵ = 4.82 mm1
c = 16.6241 (13) ÅT = 293 K
V = 1789.8 (3) Å3Block, colourless
Z = 40.20 × 0.15 × 0.12 mm
Data collection top
Bruker APEXII CCD
diffractometer
3654 independent reflections
Radiation source: fine-focus sealed tube3183 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.026
ω and ϕ scansθmax = 26.4°, θmin = 2.5°
Absorption correction: multi-scan
SHELXS97 (Sheldrick,2008)
h = 1010
Tmin = 0.423, Tmax = 0.617k = 1316
10693 measured reflectionsl = 1120
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.038H-atom parameters constrained
wR(F2) = 0.102 w = 1/[σ2(Fo2) + (0.0406P)2 + 1.2463P]
where P = (Fo2 + 2Fc2)/3
S = 1.05(Δ/σ)max < 0.001
3654 reflectionsΔρmax = 0.55 e Å3
184 parametersΔρmin = 0.54 e Å3
0 restraintsAbsolute structure: Flack & Bernardinelli (2000), 614 Friedel pairs
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.022 (13)
Crystal data top
C16H22Br2Cl2V = 1789.8 (3) Å3
Mr = 445.06Z = 4
Orthorhombic, P212121Mo Kα radiation
a = 8.2594 (7) ŵ = 4.82 mm1
b = 13.0352 (11) ÅT = 293 K
c = 16.6241 (13) Å0.20 × 0.15 × 0.12 mm
Data collection top
Bruker APEXII CCD
diffractometer
3654 independent reflections
Absorption correction: multi-scan
SHELXS97 (Sheldrick,2008)
3183 reflections with I > 2σ(I)
Tmin = 0.423, Tmax = 0.617Rint = 0.026
10693 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.038H-atom parameters constrained
wR(F2) = 0.102Δρmax = 0.55 e Å3
S = 1.05Δρmin = 0.54 e Å3
3654 reflectionsAbsolute structure: Flack & Bernardinelli (2000), 614 Friedel pairs
184 parametersAbsolute structure parameter: 0.022 (13)
0 restraints
Special details top

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > 2σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.3469 (4)0.4202 (3)0.7271 (2)0.0346 (8)
C20.1795 (4)0.3776 (4)0.7462 (3)0.0440 (9)
C30.2012 (4)0.4409 (4)0.6715 (2)0.0446 (9)
C40.1967 (6)0.3884 (4)0.5903 (3)0.0570 (12)
H4A0.09150.39990.56590.068*
H4B0.20950.31510.59790.068*
C50.3291 (6)0.4270 (5)0.5327 (3)0.0598 (13)
H5A0.29270.41880.47750.072*
H5B0.34800.49940.54210.072*
C60.4858 (7)0.3684 (5)0.5444 (3)0.0721 (15)
H6A0.55650.38530.49980.086*
H6B0.46100.29590.54010.086*
C70.5838 (5)0.3841 (3)0.6231 (2)0.0446 (9)
C80.4798 (5)0.3470 (3)0.6986 (2)0.0354 (8)
H80.42470.28400.68170.043*
C90.5846 (5)0.3179 (3)0.7684 (2)0.0384 (8)
H90.65270.26190.76110.046*
C100.5903 (4)0.3636 (3)0.8394 (2)0.0373 (8)
C110.4874 (5)0.4553 (3)0.8571 (2)0.0370 (8)
H110.40090.43460.89400.044*
C120.4109 (5)0.5026 (3)0.7827 (2)0.0391 (8)
H12A0.32280.54750.79870.047*
H12B0.49080.54360.75450.047*
C130.1283 (6)0.5488 (4)0.6685 (3)0.0684 (14)
H13A0.13010.57840.72140.103*
H13B0.01850.54480.64980.103*
H13C0.19040.59070.63250.103*
C140.7278 (9)0.3099 (6)0.6141 (4)0.093 (2)
H14A0.80670.32420.65500.139*
H14B0.77610.31880.56200.139*
H14C0.69040.24060.61960.139*
C150.6474 (9)0.4891 (5)0.6292 (4)0.0845 (19)
H15A0.55910.53650.63450.127*
H15B0.70830.50520.58160.127*
H15C0.71650.49430.67540.127*
C160.6964 (5)0.3222 (4)0.9042 (3)0.0507 (10)
H16A0.76450.37690.92470.061*
H16B0.76650.26980.88170.061*
Cl30.14150 (16)0.24471 (10)0.74083 (8)0.0694 (3)
Cl40.06998 (15)0.42878 (14)0.82812 (8)0.0734 (4)
Br10.61787 (8)0.56321 (4)0.90951 (3)0.07068 (18)
Br20.57150 (8)0.26329 (6)0.99305 (4)0.0885 (2)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0338 (17)0.035 (2)0.0352 (18)0.0032 (15)0.0007 (13)0.0027 (15)
C20.0327 (18)0.053 (3)0.046 (2)0.0103 (17)0.0056 (15)0.0024 (19)
C30.0342 (18)0.051 (2)0.048 (2)0.0075 (18)0.0073 (15)0.010 (2)
C40.051 (2)0.076 (3)0.045 (2)0.021 (2)0.0154 (19)0.004 (2)
C50.066 (3)0.080 (3)0.033 (2)0.020 (3)0.0090 (18)0.011 (2)
C60.075 (3)0.091 (4)0.051 (3)0.017 (3)0.001 (2)0.001 (3)
C70.045 (2)0.055 (2)0.0338 (19)0.007 (2)0.0081 (16)0.0015 (17)
C80.0395 (19)0.033 (2)0.0341 (19)0.0040 (15)0.0043 (14)0.0020 (15)
C90.0385 (19)0.0315 (19)0.045 (2)0.0062 (15)0.0033 (16)0.0031 (16)
C100.0346 (18)0.040 (2)0.0373 (19)0.0006 (16)0.0011 (15)0.0059 (16)
C110.0401 (19)0.037 (2)0.0336 (19)0.0006 (15)0.0026 (14)0.0077 (16)
C120.040 (2)0.036 (2)0.041 (2)0.0055 (16)0.0017 (16)0.0041 (16)
C130.052 (3)0.075 (4)0.079 (3)0.019 (3)0.015 (2)0.016 (3)
C140.085 (4)0.112 (5)0.082 (4)0.024 (4)0.046 (4)0.006 (4)
C150.097 (5)0.082 (4)0.074 (4)0.046 (4)0.021 (3)0.004 (3)
C160.046 (2)0.057 (3)0.049 (2)0.0047 (18)0.0030 (19)0.017 (2)
Cl30.0657 (7)0.0632 (8)0.0793 (8)0.0286 (6)0.0057 (6)0.0147 (6)
Cl40.0472 (6)0.1082 (11)0.0649 (7)0.0060 (7)0.0215 (5)0.0002 (8)
Br10.0901 (4)0.0583 (3)0.0637 (3)0.0039 (3)0.0277 (3)0.0181 (2)
Br20.0869 (4)0.1127 (5)0.0659 (4)0.0004 (4)0.0151 (3)0.0420 (3)
Geometric parameters (Å, º) top
C1—C121.513 (5)C8—H80.9800
C1—C21.524 (5)C9—C101.323 (6)
C1—C81.529 (5)C9—H90.9300
C1—C31.541 (5)C10—C161.489 (6)
C2—C31.502 (6)C10—C111.495 (5)
C2—Cl31.763 (5)C11—C121.520 (5)
C2—Cl41.765 (4)C11—Br11.975 (4)
C3—C41.514 (7)C11—H110.9800
C3—C131.531 (7)C12—H12A0.9700
C4—C51.538 (6)C12—H12B0.9700
C4—H4A0.9700C13—H13A0.9600
C4—H4B0.9700C13—H13B0.9600
C5—C61.515 (8)C13—H13C0.9600
C5—H5A0.9700C14—H14A0.9600
C5—H5B0.9700C14—H14B0.9600
C6—C71.552 (7)C14—H14C0.9600
C6—H6A0.9700C15—H15A0.9600
C6—H6B0.9700C15—H15B0.9600
C7—C151.470 (7)C15—H15C0.9600
C7—C141.540 (8)C16—Br21.959 (4)
C7—C81.596 (5)C16—H16A0.9700
C8—C91.497 (5)C16—H16B0.9700
C12—C1—C2116.6 (3)C9—C8—H8106.2
C12—C1—C8112.4 (3)C1—C8—H8106.2
C2—C1—C8119.2 (3)C7—C8—H8106.2
C12—C1—C3121.0 (3)C10—C9—C8126.8 (3)
C2—C1—C358.7 (3)C10—C9—H9116.6
C8—C1—C3118.9 (3)C8—C9—H9116.6
C3—C2—C161.2 (2)C9—C10—C16120.2 (4)
C3—C2—Cl3121.2 (3)C9—C10—C11121.0 (3)
C1—C2—Cl3120.6 (3)C16—C10—C11118.8 (3)
C3—C2—Cl4119.5 (3)C10—C11—C12113.6 (3)
C1—C2—Cl4119.2 (3)C10—C11—Br1110.2 (3)
Cl3—C2—Cl4108.6 (2)C12—C11—Br1107.3 (3)
C2—C3—C4119.1 (4)C10—C11—H11108.5
C2—C3—C13118.9 (4)C12—C11—H11108.5
C4—C3—C13112.1 (4)Br1—C11—H11108.5
C2—C3—C160.1 (2)C1—C12—C11110.7 (3)
C4—C3—C1118.4 (4)C1—C12—H12A109.5
C13—C3—C1119.2 (4)C11—C12—H12A109.5
C3—C4—C5112.9 (4)C1—C12—H12B109.5
C3—C4—H4A109.0C11—C12—H12B109.5
C5—C4—H4A109.0H12A—C12—H12B108.1
C3—C4—H4B109.0C3—C13—H13A109.5
C5—C4—H4B109.0C3—C13—H13B109.5
H4A—C4—H4B107.8H13A—C13—H13B109.5
C6—C5—C4111.3 (4)C3—C13—H13C109.5
C6—C5—H5A109.4H13A—C13—H13C109.5
C4—C5—H5A109.4H13B—C13—H13C109.5
C6—C5—H5B109.4C7—C14—H14A109.5
C4—C5—H5B109.4C7—C14—H14B109.5
H5A—C5—H5B108.0H14A—C14—H14B109.5
C5—C6—C7119.2 (5)C7—C14—H14C109.5
C5—C6—H6A107.5H14A—C14—H14C109.5
C7—C6—H6A107.5H14B—C14—H14C109.5
C5—C6—H6B107.5C7—C15—H15A109.5
C7—C6—H6B107.5C7—C15—H15B109.5
H6A—C6—H6B107.0H15A—C15—H15B109.5
C15—C7—C14108.4 (5)C7—C15—H15C109.5
C15—C7—C6111.6 (5)H15A—C15—H15C109.5
C14—C7—C6103.8 (4)H15B—C15—H15C109.5
C15—C7—C8114.9 (4)C10—C16—Br2112.2 (3)
C14—C7—C8107.6 (4)C10—C16—H16A109.2
C6—C7—C8110.0 (4)Br2—C16—H16A109.2
C9—C8—C1109.4 (3)C10—C16—H16B109.2
C9—C8—C7112.0 (3)Br2—C16—H16B109.2
C1—C8—C7116.2 (3)H16A—C16—H16B107.9

Experimental details

Crystal data
Chemical formulaC16H22Br2Cl2
Mr445.06
Crystal system, space groupOrthorhombic, P212121
Temperature (K)293
a, b, c (Å)8.2594 (7), 13.0352 (11), 16.6241 (13)
V3)1789.8 (3)
Z4
Radiation typeMo Kα
µ (mm1)4.82
Crystal size (mm)0.20 × 0.15 × 0.12
Data collection
DiffractometerBruker APEXII CCD
diffractometer
Absorption correctionMulti-scan
SHELXS97 (Sheldrick,2008)
Tmin, Tmax0.423, 0.617
No. of measured, independent and
observed [I > 2σ(I)] reflections
10693, 3654, 3183
Rint0.026
(sin θ/λ)max1)0.625
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.038, 0.102, 1.05
No. of reflections3654
No. of parameters184
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.55, 0.54
Absolute structureFlack & Bernardinelli (2000), 614 Friedel pairs
Absolute structure parameter0.022 (13)

Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 2012), WinGX (Farrugia, 2012).

 

Acknowledgements

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

References

First citationBenharref, A., El Karroumi, J., El Ammari, L., Saadi, M. & Berraho, M. (2013). Acta Cryst. E69, o1037–o1038.  CSD CrossRef CAS IUCr Journals
First citationBruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.
First citationCremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354–1358.  CrossRef CAS Web of Science
First citationDaoubi, M., Duran-Patron, R., Hmamouchi, M., Hernandez-Galan, R., Benharref, A. & Isidro, G. C. (2004). Pest Manag. Sci. 60, 927–932.  Web of Science CrossRef PubMed CAS
First citationEl Haib, A., Benharref, A., Parres-Maynadie, S., Manoury, E., Urrutigoıty, M. & Gouygou, M. (2011). Tetrahedron Asymmetry, 22, 101–108.  Web of Science CrossRef CAS
First citationEl Jamili, H., Auhmani, A., Dakir, M., Lassaba, E., Benharref, A., Pierrot, M., Chiaroni, A. & Riche, C. (2002). Tetrahedron Lett. 43, 6645–6648.  CAS
First citationFarrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854.  Web of Science CrossRef CAS IUCr Journals
First citationFlack, H. D. & Bernardinelli, G. (2000). J. Appl. Cryst. 33, 1143–1148.  Web of Science CrossRef CAS IUCr Journals
First citationOukhrib, A., Benharref, A., Saadi, M., Berraho, M. & El Ammari, L. (2013). Acta Cryst. E69, o521–o522.  CSD CrossRef CAS IUCr Journals
First citationOurhriss, N., Benharref, A., Saadi, M., El Ammari, L. & Berraho, M. (2013). Acta Cryst. E69, o275.  CSD CrossRef IUCr Journals
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals

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