7-Hy­droxy-8-isopropyl-1,1,4a-trimethyl-4a,9,10,10a-tetra­hydro-phenanthren-2(1H)-one

Ahmed Benharref; Essêdiya Lassaba; Noureddine Mazoir; Jean-Claude Daran; Moha Berraho

doi:10.1107/S1600536811009561

. 2011 Mar 19;67(Pt 4):o906. doi: 10.1107/S1600536811009561

7-Hydroxy-8-isopropyl-1,1,4a-trimethyl-4a,9,10,10a-tetrahydro-phenanthren-2(1H)-one

Ahmed Benharref ^a, Essêdiya Lassaba ^a,^*, Noureddine Mazoir ^a, Jean-Claude Daran ^b, Moha Berraho ^a

PMCID: PMC3099889 PMID: 21754180

Abstract

The title compound, C₂₀H₂₆O₂, was isolated from a chloroform extract of Tetraclinis articulata wood. The molecule contains three fused rings which exhibit different conformations. The non-aromatic oxo-substituted ring has a screw-boat conformation, while the central ring has a half-chair conformation. In the crystal, molecules are linked to each other by intermolecular O—H⋯O hydrogen bonds involving the carbonyl and hydroxy groups.

Related literature

For background to the biological activity of diterpenoids, see: Atta-ur-Rahman & Choudhary (1999 ▶); Azucena & Mobashery (2001 ▶); Panter et al. (2002 ▶); Ulusu et al. (2002 ▶). For their use in traditional medicine, see: Bellakhdar (1997 ▶) and for their medicinal properties, see: Barrero et al. (2003 ▶); Comte et al. (1995 ▶); Evidente et al. (1997 ▶). For the synthesis see: Zeroual et al. (2007 ▶). For conformational analysis, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C₂₀H₂₆O₂
M _r = 298.41
Monoclinic,
a = 11.6731 (8) Å
b = 6.4314 (4) Å
c = 12.1488 (10) Å
β = 111.592 (9)°
V = 848.06 (11) Å³
Z = 2
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 180 K
0.48 × 0.36 × 0.29 mm

Data collection

Agilent Xcalibur Eos Gemini ultra diffractometer
9252 measured reflections
1893 independent reflections
1591 reflections with I > 2σ(I)
R _int = 0.066

Refinement

R[F ² > 2σ(F ²)] = 0.047
wR(F ²) = 0.128
S = 1.03
1893 reflections
207 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.18 e Å⁻³
Δρ_min = −0.22 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; 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 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811009561/fj2405sup1.cif

e-67-0o906-sup1.cif^{(18.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811009561/fj2405Isup2.hkl

e-67-0o906-Isup2.hkl^{(91.2KB, hkl)}

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2⋯O1ⁱ	0.84	2.03	2.791 (3)	150

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Symmetry code: (i) Inline graphic .

Acknowledgments

We thank the National Center of Scientific and Technological Research (CNRST) for supporting our scientific research.

supplementary crystallographic information

Comment

Among the diterpenoids, the class with the phenantrene skeleton may have biological activities which have been recently reported (Atta-ur-Rahman et al.,1999; Azucena et al.,2001; Panter et al., 2002; Ulusu et al., 2002). These diterpenoids are often isolated from the medicinal plants. In our study, we were interested to the medicinal plant, Tetraclinis articulata which is used in Moroccan traditional medicine (Bellakhdar, 1997). Some of its oxygenated compounds are effective as an antifongic (Evidente et al., 1997), cytotoxic (Comte et al., 1995) and inhibit various human leukocyte functions(Barrero et al., 2003). In order to isolate similar compounds, we have studied the chloroform extract of Tetraclinis articulata wood. Thus, the extraction with chloroform using a soxhlet apparatus allow us isolate the totarolenone (7-hydroxy-8-isporpyl-1,1,4a-trimethyl- 4a,9,10,10a- tetrahydro-1H-phenanthren-3-one) a derivative of totarolone (7-hydroxy-8-isporpyl-1,1,4a-trimethyl-3,4,4a,9,10,10a- hexahydophenantren-2-one) (Zeroual et al., 2007). The structure of this new product was determined by NMR spectral analysis of 1H, 13 C and mass spectroscopy and confirmed by its single-crystal X-ray structure. The molecule (I) is built up from three fused six-membered rings. The non aromatic oxo-substituted ring has a screw boat conformation, as indicated by the total puckering amplitude QT = 0.490 (3)Å and spherical polar angle θ =67.1 (4)° with φ = 272.2 (3)°. While the central ring has a half chair conformation with QT = 0.545 (3) Å, θ =53.4 (3)°, φ = 278.5 (3)° (Cremer & Pople, 1975). Molecules are linked by intermolecular O—H···O hydrogen bonds (Table 1, Figure 2) involving the carbonyl and the hydroxy groups and propagate in chain parallel to the a axis.

Experimental

50 g of wood powder Tetraclinis articulata was extracted with chloroform in Soxhlet apparatus during 24 h. After evaporating the solvent under reduced pressure, a residue of 3.2 g was obtained. Chromatography on a column of silica gel of this residue eluting with hexan - ethyl acetate (94 / 4), allowed us to isolate in pure form 640 mg of 7-hydroxy-8-isporpyl- 1, 1,4 a-trimethyl-4a, 9,10,10 a-tetrahydro-1H-phenanthrene-3-one. Crystallization of this product was performed at room temperature in a solution of ethyl acetate.