1-(4a,8-Dimethyl-1,2,3,4,4a,5,6,8a-octa­hydro­naphthalen-2-yl)-3-(4-methyl­phen­yl)prop-2-en-1-one

Mohamed Tebbaa; Ahmed Benharref; Moha Berraho; Daniel Avignant; Abdelghani Oudahmane; Mohamed Akssira

doi:10.1107/S1600536811016941

. 2011 May 11;67(Pt 6):o1381. doi: 10.1107/S1600536811016941

1-(4a,8-Dimethyl-1,2,3,4,4a,5,6,8a-octahydronaphthalen-2-yl)-3-(4-methylphenyl)prop-2-en-1-one

Mohamed Tebbaa ^a,^*, Ahmed Benharref ^b, Moha Berraho ^b, Daniel Avignant ^c, Abdelghani Oudahmane ^c, Mohamed Akssira ^a

PMCID: PMC3120299 PMID: 21754771

Abstract

The title compound, C₂₂H₂₈O, was isolated from the aerial part of Inula viscosa (L) Aiton [or Dittrichia viscosa (L) Greuter]. The cyclohexene ring has a half-chair conformation, whereas the cyclohexane ring displays a chair conformation being substituted at position 2 by a 3-(4-methylphenyl)prop-2-enoyl group. In the crystal, weak intermolecular C—H⋯O hydrogen bonds link molecules into chains in the [010] direction.

Related literature

For background to the medicinal interest in Inula viscosa (L) Aiton [or Dittrichia viscosa (L) Greuter], see: Shtacher & Kasshman (1970 ▶); Bohlmann & Gupta (1982 ▶); Azoulay et al. (1986 ▶); Bohlmann et al. (1977 ▶); Ceccherelli et al. (1988 ▶). For details of the synthesis, see: Kutney & Singh (1984 ▶). For conformational analysis, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C₂₂H₂₈O
M _r = 308.44
Monoclinic,
a = 7.1577 (2) Å
b = 10.3456 (2) Å
c = 12.3663 (3) Å
β = 95.557 (1)°
V = 911.43 (4) Å³
Z = 2
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 298 K
0.37 × 0.16 × 0.16 mm

Data collection

Bruker X8 APEXII CCD area-detector diffractometer
8379 measured reflections
1957 independent reflections
1834 reflections with I > 2σ(I)
R _int = 0.020

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.102
S = 1.11
1957 reflections
212 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.16 e Å⁻³
Δρ_min = −0.15 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; 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/S1600536811016941/cv5077sup1.cif

e-67-o1381-sup1.cif^{(19.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811016941/cv5077Isup2.hkl

e-67-o1381-Isup2.hkl^{(94.3KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811016941/cv5077Isup3.cml

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
C17—H17⋯O1ⁱ	0.93	2.51	3.383 (3)	156

Open in a new tab

Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank the National Centre of Scientific and Technological Research (CNRST) for support.

supplementary crystallographic information

Comment

Our work lies within the framework of the valorization of medicinal plants and concerns 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; Bohlmann & Gupta, 1982), which exhibits some pharmacological activities (Azoulay et al., 1986). This plant has been the subject of chemical investigation in terms of isolating sesquiterpene lactones (Bohlmann et al., 1977) and sesquiterpene acids (Ceccherelli et al., 1988). The isocostic acid is a major constituent of the dichloromethane extract of the Inula viscosa (L). The literature does not report any results on the transformation of this acid. In order to prepare products with high added value, we studied the reactivity of this acid. Thus, from this acid, we have prepared by reaction of Curtius the 1 - (4a, 8dimethyl-1,2,3,4, 4a,5,6,8a-octahydronaphthalen-2-yl)-ethanone, which was synthesized by Kutney et al. (1984). The condensation of this ketone with para- methylbenzaldehyde in the presence of sodium hydroxide allowed us to obtain the title compound (I) with a good yield of 80%. The structure of this new derivative of isocostic acid was established by NMR spectral analysis of 1H, 13 C and mass spectroscopy and confirmed by its single-crystal X-ray structure.

The molecule of (I) is built up from two fused six-membered rings, substituted at position 2 by 4-methylphenylpropenoyl group The molecular structure of (I), Fig.1, shows the cyclohexane ring to adopt a chair conformation, as indicated by the total puckering amplitude QT = 0.5617 (17)Å and spherical polar angle θ =7.25 (17)° with φ = 260.6 (14)°. While the cyclohexene ring has a half chair conformation with QT = 0.5071 (18) Å, θ =49.7 (2)°, φ = 12.5 (6)° (Cremer & Pople, 1975). In the crystal structure, weak intermolecular C—H···O hydrogen bonds (Table 1) link molecules into chains in [010] (Fig. 2).

Experimental

In a flask was introduced a mixture of 500 mg (2.42 mmol), of 1 - (4a, 8-dimethyl-1, 2,3,4,4a,5,6,8a-octahydronaphthalen-2-yl)-ethanone, 257 mg (2.42 mmol.) of para chlor-benzaldehyde, 30 ml of anhydrous ethanol and 1 ml of a solution of sodium hydroxide(2 N). The mixture was stirred for three hours at room temperature. After neutralization followed by extraction three time with 20 ml of dichloromethane, the organic phase is dried over sodium sulfate, then evaporated under vacuum. Chromatography on a column of silica gel with hexane-ethyl acetate (97/3) as eluent of the residue allowed us to obtain 3-(4-méthylphenyl)-1-(4a, 8-dimethyl-1,2,3,4,4a, 5,6,8a-octahydronaphthalen-2-yl)prop-2-en-1-one with a yield of 80%. The title compound is recrystallized in hexane-ethyl acetate (70/30).