1-[(2R,4aR,8R,8aR)-8-Hy­droxy-4a,8-di­methyl­perhydronaphthalen-2-yl]ethan-1-one

Mohamed Tebbaa; Ahmed Benharref; Moha Berraho; Jean-Claude Daran; Mohamed Akssira; Ahmed Elhakmaoui

doi:10.1107/S1600536811004454

. 2011 Feb 12;67(Pt 3):o601. doi: 10.1107/S1600536811004454

1-[(2R,4aR,8R,8aR)-8-Hydroxy-4a,8-dimethylperhydronaphthalen-2-yl]ethan-1-one

Mohamed Tebbaa ^a, Ahmed Benharref ^b, Moha Berraho ^b, Jean-Claude Daran ^c, Mohamed Akssira ^a, Ahmed Elhakmaoui ^a,^*

PMCID: PMC3052061 PMID: 21522359

Abstract

The title compound, C₁₄H₂₄O₂, was synthesized from ilicic acid, which was isolated from the aerial part of Inula Viscosa (L) Aiton [or Dittrichia Viscosa (L) Greuter]. The molecule contains two fused six-membered rings, which both display a chair conformation. In the crystal, molecules are linked into chains propagating along the b axis by intermolecular O—H⋯O hydrogen bonds.

Related literature

For the synthesis, see: Barrero et al. (2009 ▶). For the medicinal interest in Inula Viscosa (L) Aiton [or Dittrichia Viscosa (L) Greuter], see: Shtacher & Kasshman, (1970 ▶); Bohlmann et al. (1977 ▶); Chiappini et al. (1982 ▶) and for the pharmacological interest, see: Azoulay et al. (1986 ▶); Bohlmann et al. (1977 ▶); Ceccherelli et al. (1988 ▶). For background to phytochemical studies of plants, see: Geissman & Toribio (1967 ▶). For conformational analysis, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C₁₄H₂₄O₂
M _r = 224.33
Monoclinic,
a = 6.4919 (7) Å
b = 9.4057 (9) Å
c = 10.3638 (11) Å
β = 97.286 (10)°
V = 627.71 (11) Å³
Z = 2
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 180 K
0.6 × 0.25 × 0.15 mm

Data collection

Agilent Eos Gemini Ultra diffractometer
6571 measured reflections
1362 independent reflections
1262 reflections with I > 2σ(I)
R _int = 0.047

Refinement

R[F ² > 2σ(F ²)] = 0.043
wR(F ²) = 0.119
S = 1.09
1362 reflections
152 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.28 e Å⁻³
Δρ_min = −0.24 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXL97 (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 I, global. DOI: 10.1107/S1600536811004454/fj2393sup1.cif

e-67-0o601-sup1.cif^{(17.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811004454/fj2393Isup2.hkl

e-67-0o601-Isup2.hkl^{(65.8KB, 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
O1—H2⋯O2ⁱ	0.84 (3)	2.05 (3)	2.883 (2)	169 (3)

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Symmetry code: (i) Inline graphic .

Acknowledgments

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

supplementary crystallographic information

Comment

The ilicic acid is one of the main components of the extracts of the aerial parts Inula viscose. This natural acid is a major constituent of the dichloromethane extract of the Inula Viscosa (L) Aiton [or Dittrichia Viscosa (L) Greuter]. This plant is widespread in Mediterranean area and extends to the Atlantic cost of Morocco. It is a well known medicinal plant (Shtacher & Kasshman, 1970; Chiappini et al., 1982) and has some pharmacological activities (Azoulay et al., 1986). the Inula Viscosa (L) Aiton has been the subject of chemical investigation in terms of isolating sesquiterpene lactones (Bohlmann et al., 1977), sesquiterpene acids (Ceccherelli et al., 1988; Geissman et al.1967). The literature report one article on the transformation of the ilicic acid (Barrero et al., 2009). In order to prepare products with high added value, used in the industry pharmacological or cosmetic, we have studied the reactivity of this acid. Thus, with the reaction Curtius, we synthesized the title compound(1R, 2R, 6R, 9R)-9-acethyl-2,6-dimethylbicyclo [4.4.0]decan-2-ol) with à yield 50%. The structure of this new derivative of ilicic acid was determined by NMR spectral analysis of 1H, 13 C and mass spectroscopy and confirmed by its single-crystal X-ray structure. The molecule is built up from two fused six-membered rings. The molecular structure of (I),Fig.1, shows the two rings to adopt a perfect chair conformation as indicated by Cremer & Pople (1975) puckering parameters Q(T)= 0.554 (2)Å and spherical polar angle θ = 178.1 (2)° with φ = 36 (7)° for the first ring (C1,C2··· C6) and Q(T)= 0.597 (2)Å with a spherical polar angle θ = 178.71 (19)° and φ = 108 (5)° for the second ring (C1, C6···C10)(Cremer and Pople,1975). In the crystal structure, molecules are linked into chains (Fig. 2) running along the b axis by intermolecular O—H···O hydrogen bonds (Table 1) involving the O1 and O2 atoms.

Experimental

A solution containing the ilicic acid 1 g (3.96 mmol) and Et3N 0.82 ml (5.895 mmol) in dry THF (100 ml) was cooled at -10 °C. Ethyl chloroformate 0,56 ml (5.95 mm l) was added dropwise and the reaction mixture was stirred at this temperature for 1 h. A solution of NaN3 0.43 g (6.74 mmol) in H2O (10 ml) was then added in one portion. After 1.5 h at 0 °C, the resulting heterogeous mixture was filttered, the organic solvent was removed under reduced pressure and the aqueous phase was extracted tree time with ether (3 × 50 ml). The combined organic layers were dried over MgSO4, and concentrated in vacuo. The crude acyl-azide was then dissolved in toluene (50 ml) and the resulting solution was refluxed for 1 h. Then a solution of hydrochloric acid at 10% was added to the reaction mixture which is remized at reflux for 2 h. After extraction, the organic phase is washed with water and brine, dried over anhydrous Na2SO4, filtered and concentrated under vacuum. The product was purified by column chromatography over silica gel (hexane/ethyl acetate 95/5). The title compound was recrystallized in dichloromethane.