6-Hydr­oxy-7-isopropyl-1,1,4a-trimethyl-2,3,4,4a,10,10a-hexa­hydro­phenanthren-9(1H)-one

Nezha Rajouani; My Youssef Ait Itto; Ahmed Benharref; Aziz Auhmani; Jean-Claude Daran

doi:10.1107/S1600536808007769

. 2008 Mar 29;64(Pt 4):o762. doi: 10.1107/S1600536808007769

6-Hydroxy-7-isopropyl-1,1,4a-trimethyl-2,3,4,4a,10,10a-hexahydrophenanthren-9(1H)-one

Nezha Rajouani ^a, My Youssef Ait Itto ^a, Ahmed Benharref ^a, Aziz Auhmani ^a, Jean-Claude Daran ^b,^*

PMCID: PMC2960938 PMID: 21202151

Abstract

The title compound, C₂₀H₂₈O₂, commonly named Sugiol, is a natural oxygenated diterpene that we have isolated for the first time from a hexane extract of the fruits of Juniperus Oxycedrus L. Its X-ray crystal structure determination confirms an abietane skeleton which was predicted by spectroscopic analysis, mainly by ¹H and ¹³C NMR. The cyclohexane ring adopts a flattened chair conformation, while the cyclohexene ring adopts an envelope conformation. The molecules are linked through O—H⋯O hydrogen bonds to form a zigzag chain extending parallel to the c axis.

Related literature

For related literature, see: Bai-Ping & Isao (1991 ▶); Bouhlal et al. (1988 ▶); Cremer & Pople (1975 ▶); Iwamato et al. (2003 ▶); Politi et al. (2003 ▶); Ulubelen et al. (1997 ▶).

Experimental

Crystal data

C₂₀H₂₈O₂
M _r = 300.42
Orthorhombic,
a = 9.6060 (4) Å
b = 12.6617 (6) Å
c = 14.0920 (7) Å
V = 1713.99 (14) Å³
Z = 4
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 180 (2) K
0.31 × 0.16 × 0.07 mm

Data collection

Oxford Diffraction Xcalibur diffractometer
Absorption correction: none
13398 measured reflections
2003 independent reflections
1212 reflections with I > 2σ(I)
R _int = 0.068

Refinement

R[F ² > 2σ(F ²)] = 0.046
wR(F ²) = 0.154
S = 1.05
2003 reflections
205 parameters
H-atom parameters constrained
Δρ_max = 0.36 e Å⁻³
Δρ_min = −0.38 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2007 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2007 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEPIII (Burnett & Johnson, 1996 ▶), ORTEP-3 for Windows (Farrugia, 1997 ▶) and PLATON (Spek, 2003 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808007769/pk2088sup1.cif

e-64-0o762-sup1.cif^{(18.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808007769/pk2088Isup2.hkl

e-64-0o762-Isup2.hkl^{(96.5KB, 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
O6—H6⋯O9ⁱ	0.82	1.84	2.642 (4)	165

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Symmetry code: (i) Inline graphic .

supplementary crystallographic information

Comment

Juniperus oxycedrus L. has been used in traditional folk medicine for the treatment of chronic eczema and other several skin diseases (Bouhlal et al., 1988). Diterpenes are among the identified chemical constituents of this plant. They are of great interest with respect to their biological activity including antitumor, antituberculous and antimalarial effects (Iwamato et al., 2003; Politi et al., 2003; Ulubelen et al., 1997).

The structure of the title compound is built up by three fused six-membered rings A, B and C (Fig. 1). B displays an envelope conformation with puckering parameters, Q=0.510 (4) Å, θ= 124.6 (4)° and φ= 227.1 (6)° (Cremer & Pople, 1975) whereas C has a flattened chair conformation with Q= 0.546 (4) Å, θ = 5.0 (4) and φ = 234 (5)°. A is an aromatic ring and it is perfectly planar. The molecules are linked through O—H···O hydrogen bonds involving the hydroxyl group as a donor and the ketone oxygen as an acceptor yielding a zig zag chain developing parallel to the c axis (Fig. 2, Table 1).

Experimental

In order to isolate similar compounds, we have studied the chemical composition of the fruits of Juniperus oxycedrus L. Thus, 203 g of pulverized cones was extracted with hexane. The solvent was evaporated under reduced pressure to give 14.3 g of the crude hexanic extract which was purified on silica gel column chromatography using hexane–AcOEt (97:3) as eluent, to give crystals of Sugiol (I). All ¹H and ¹³C NMR spectroscopic data of the isolated product were in full accord with the litterature (Bai-Ping & Isao, 1991).