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

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.

Key indicators

• Single-crystal X-ray study
• T = 180 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.043
• wR factor = 0.119
• Data-to-parameter ratio = 9.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          1

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           26.37
           From the CIF: _reflns_number_total               1362
           Count of symmetry unique reflns         1362
           Completeness (_total/calc)            100.00%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         0
           Fraction of Friedel pairs measured     0.000
           Are heavy atom types Z>Si present         no
PLAT380_ALERT_4_G Check Incorrectly? Oriented X(sp2)-Methyl Moiety        C14
PLAT791_ALERT_4_G Note: The Model has Chirality at C1     (Verify)          R
PLAT791_ALERT_4_G Note: The Model has Chirality at C2     (Verify)          R
PLAT791_ALERT_4_G Note: The Model has Chirality at C6     (Verify)          R
PLAT791_ALERT_4_G Note: The Model has Chirality at C9     (Verify)          R

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   1 ALERT level C = Check and explain
   6 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   6 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check


checkCIF publication errors

Alert level A
PUBL024_ALERT_1_A The number of authors is greater than 5.
              Please specify the role of each of the co-authors
              for your paper.

Author Response: The authors M. Tebbaa and A. Benharref : isolation of the substance and analyse by NMR. J.C.Daran : data collection. M.Berraho : resolution of the structure and preparation of the cif file . M. Akssira and A. El Hakmaoui are director and co-director of thesis.

   1 ALERT level A = Data missing that is essential or data in wrong format
   0 ALERT level G = General alerts. Data that may be required is missing

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S1. 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.

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 et al. (1967). For conformational analysis, see: Cremer & Pople (1975).

S2. 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.

S3. Refinement

Except H2, all H atoms were fixed geometrically and treated as riding with C—H = 0.96 Å (methyl),0.97 Å (methylene), 0.98Å (methine) with U_iso(H) = 1.2Ueq(methylene, methine and OH) or U_iso(H) = 1.5Ueq(methyl). In the absence of significant anomalous scattering, the absolute configuration could not be reliably determined and thus 1167 Friedel pairs were merged and any references to the Flack parameter were removed.

Computing details

Data collection: CrysAlis PRO (Agilent, 2010); cell refinement: CrysAlis PRO (Agilent, 2010); data reduction: CrysAlis PRO (Agilent, 2010); 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).

Figures

	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.
	Fig. 2. Partial packing view showing the O—H···O interactions (dashed lines)and the formation of a chain parallel to the b axis. H atoms not involved in hydrogen bonding have been omitted for clarity. [Symmetry code: (i)1 - x,-1/2 + y,-z + 2]

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

Crystal data

C14H24O2	F(000) = 248
Mr = 224.33	Dx = 1.187 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 6571 reflections
a = 6.4919 (7) Å	θ = 2.9–26.4°
b = 9.4057 (9) Å	µ = 0.08 mm^−1
c = 10.3638 (11) Å	T = 180 K
β = 97.286 (10)°	Prism, colourless
V = 627.71 (11) Å^3	0.6 × 0.25 × 0.15 mm
Z = 2

Data collection

Agilent Eos Gemini Ultra diffractometer	1262 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.047
Graphite monochromator	θmax = 26.4°, θmin = 2.9°
Detector resolution: 16.1978 pixels mm^-1	h = −8→8
ϕ and ω scans	k = −11→11
6571 measured reflections	l = −12→12
1362 independent reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.119	H atoms treated by a mixture of independent and constrained refinement
S = 1.09	w = 1/[σ^2(Fo^2) + (0.0935P)^2 + 0.0033P] where P = (Fo^2 + 2Fc^2)/3
1362 reflections	(Δ/σ)max < 0.001
152 parameters	Δρmax = 0.28 e Å^−3
1 restraint	Δρmin = −0.24 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
H2	0.822 (5)	0.709 (4)	0.829 (3)	0.039 (8)*
C1	0.8653 (3)	0.9919 (2)	0.80775 (19)	0.0185 (4)
H1	0.9924	0.9851	0.8695	0.022*
C2	0.8777 (3)	0.8642 (2)	0.7154 (2)	0.0214 (4)
C3	1.0704 (3)	0.8816 (2)	0.6454 (2)	0.0261 (5)
H3A	1.1934	0.8693	0.7081	0.031*
H3B	1.0705	0.8072	0.5806	0.031*
C4	1.0826 (3)	1.0251 (3)	0.5791 (2)	0.0296 (5)
H4A	0.9684	1.0339	0.5095	0.036*
H4B	1.2114	1.0311	0.5411	0.036*
C5	1.0729 (3)	1.1462 (2)	0.6757 (2)	0.0269 (5)
H5A	1.0766	1.2360	0.6300	0.032*
H5B	1.1947	1.1420	0.7403	0.032*
C6	0.8776 (3)	1.1420 (2)	0.7452 (2)	0.0220 (5)
C7	0.9014 (4)	1.2512 (2)	0.8558 (2)	0.0262 (5)
H7A	1.0348	1.2372	0.9079	0.031*
H7B	0.9008	1.3459	0.8186	0.031*
C8	0.7305 (4)	1.2420 (2)	0.9442 (2)	0.0267 (5)
H8A	0.5973	1.2638	0.8945	0.032*
H8B	0.7565	1.3112	1.0137	0.032*
C9	0.7245 (3)	1.0926 (2)	1.0020 (2)	0.0225 (4)
H9	0.8596	1.0737	1.0527	0.027*
C10	0.6895 (3)	0.9817 (2)	0.89272 (19)	0.0208 (4)
H10A	0.6867	0.8871	0.9298	0.025*
H10B	0.5572	0.9987	0.8402	0.025*
C11	0.6816 (3)	0.8367 (3)	0.6205 (2)	0.0281 (5)
H11A	0.5633	0.8342	0.6674	0.042*
H11B	0.6942	0.7472	0.5776	0.042*
H11C	0.6643	0.9114	0.5570	0.042*
C12	0.6859 (4)	1.1824 (3)	0.6488 (2)	0.0291 (5)
H12A	0.6890	1.1314	0.5688	0.044*
H12B	0.6873	1.2827	0.6321	0.044*
H12C	0.5619	1.1581	0.6854	0.044*
C13	0.5607 (4)	1.0824 (2)	1.0919 (2)	0.0254 (5)
C14	0.6262 (4)	1.0246 (3)	1.2248 (2)	0.0365 (6)
H14A	0.5094	1.0239	1.2732	0.055*
H14B	0.7341	1.0832	1.2688	0.055*
H14C	0.6770	0.9293	1.2181	0.055*
O1	0.9229 (2)	0.73764 (16)	0.79125 (15)	0.0258 (4)
O2	0.3823 (3)	1.1216 (2)	1.05879 (17)	0.0368 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0181 (9)	0.0150 (9)	0.0221 (10)	0.0001 (7)	0.0013 (7)	0.0000 (7)
C2	0.0234 (11)	0.0173 (9)	0.0236 (10)	0.0027 (8)	0.0035 (8)	0.0001 (8)
C3	0.0265 (11)	0.0247 (11)	0.0283 (11)	0.0026 (8)	0.0079 (8)	−0.0005 (9)
C4	0.0300 (11)	0.0311 (12)	0.0299 (11)	−0.0018 (9)	0.0119 (9)	0.0033 (9)
C5	0.0256 (11)	0.0237 (11)	0.0322 (11)	−0.0027 (8)	0.0065 (8)	0.0053 (9)
C6	0.0200 (10)	0.0188 (10)	0.0269 (10)	−0.0005 (7)	0.0017 (7)	0.0025 (8)
C7	0.0299 (11)	0.0163 (10)	0.0319 (11)	−0.0033 (8)	0.0016 (9)	−0.0003 (8)
C8	0.0308 (11)	0.0180 (10)	0.0309 (11)	0.0017 (9)	0.0024 (9)	−0.0025 (8)
C9	0.0258 (10)	0.0185 (10)	0.0229 (10)	0.0003 (8)	0.0026 (8)	−0.0020 (7)
C10	0.0236 (10)	0.0149 (9)	0.0241 (10)	0.0001 (8)	0.0040 (7)	−0.0014 (7)
C11	0.0253 (11)	0.0266 (11)	0.0321 (11)	−0.0011 (8)	0.0024 (9)	−0.0068 (9)
C12	0.0298 (12)	0.0263 (11)	0.0304 (11)	0.0037 (9)	0.0003 (9)	0.0055 (9)
C13	0.0325 (12)	0.0149 (9)	0.0296 (11)	0.0006 (8)	0.0070 (8)	−0.0058 (8)
C14	0.0463 (14)	0.0321 (13)	0.0324 (12)	−0.0030 (11)	0.0097 (10)	0.0025 (10)
O1	0.0279 (8)	0.0172 (7)	0.0341 (8)	0.0036 (6)	0.0103 (6)	0.0028 (6)
O2	0.0336 (9)	0.0360 (10)	0.0429 (9)	0.0095 (7)	0.0132 (7)	0.0005 (8)

Geometric parameters (Å, º)

C1—C10	1.530 (3)	C8—C9	1.530 (3)
C1—C2	1.545 (3)	C8—H8A	0.9700
C1—C6	1.560 (3)	C8—H8B	0.9700
C1—H1	0.9800	C9—C13	1.503 (3)
C2—O1	1.436 (3)	C9—C10	1.535 (3)
C2—C11	1.529 (3)	C9—H9	0.9800
C2—C3	1.532 (3)	C10—H10A	0.9700
C3—C4	1.521 (3)	C10—H10B	0.9700
C3—H3A	0.9700	C11—H11A	0.9600
C3—H3B	0.9700	C11—H11B	0.9600
C4—C5	1.524 (3)	C11—H11C	0.9600
C4—H4A	0.9700	C12—H12A	0.9600
C4—H4B	0.9700	C12—H12B	0.9600
C5—C6	1.536 (3)	C12—H12C	0.9600
C5—H5A	0.9700	C13—O2	1.222 (3)
C5—H5B	0.9700	C13—C14	1.493 (3)
C6—C7	1.533 (3)	C14—H14A	0.9600
C6—C12	1.541 (3)	C14—H14B	0.9600
C7—C8	1.528 (3)	C14—H14C	0.9600
C7—H7A	0.9700	O1—H2	0.85 (3)
C7—H7B	0.9700
C10—C1—C2	114.14 (16)	H7A—C7—H7B	107.7
C10—C1—C6	112.18 (15)	C7—C8—C9	110.07 (17)
C2—C1—C6	115.90 (15)	C7—C8—H8A	109.6
C10—C1—H1	104.3	C9—C8—H8A	109.6
C2—C1—H1	104.3	C7—C8—H8B	109.6
C6—C1—H1	104.3	C9—C8—H8B	109.6
O1—C2—C11	107.93 (18)	H8A—C8—H8B	108.2
O1—C2—C3	103.02 (16)	C13—C9—C8	110.87 (17)
C11—C2—C3	112.14 (17)	C13—C9—C10	111.32 (17)
O1—C2—C1	109.18 (15)	C8—C9—C10	110.12 (16)
C11—C2—C1	115.19 (16)	C13—C9—H9	108.1
C3—C2—C1	108.64 (17)	C8—C9—H9	108.1
C4—C3—C2	113.69 (17)	C10—C9—H9	108.1
C4—C3—H3A	108.8	C1—C10—C9	109.28 (15)
C2—C3—H3A	108.8	C1—C10—H10A	109.8
C4—C3—H3B	108.8	C9—C10—H10A	109.8
C2—C3—H3B	108.8	C1—C10—H10B	109.8
H3A—C3—H3B	107.7	C9—C10—H10B	109.8
C3—C4—C5	110.96 (17)	H10A—C10—H10B	108.3
C3—C4—H4A	109.4	C2—C11—H11A	109.5
C5—C4—H4A	109.4	C2—C11—H11B	109.5
C3—C4—H4B	109.4	H11A—C11—H11B	109.5
C5—C4—H4B	109.4	C2—C11—H11C	109.5
H4A—C4—H4B	108.0	H11A—C11—H11C	109.5
C4—C5—C6	113.21 (17)	H11B—C11—H11C	109.5
C4—C5—H5A	108.9	C6—C12—H12A	109.5
C6—C5—H5A	108.9	C6—C12—H12B	109.5
C4—C5—H5B	108.9	H12A—C12—H12B	109.5
C6—C5—H5B	108.9	C6—C12—H12C	109.5
H5A—C5—H5B	107.7	H12A—C12—H12C	109.5
C7—C6—C5	108.80 (16)	H12B—C12—H12C	109.5
C7—C6—C12	108.44 (18)	O2—C13—C14	121.2 (2)
C5—C6—C12	109.67 (17)	O2—C13—C9	121.8 (2)
C7—C6—C1	107.52 (17)	C14—C13—C9	117.03 (19)
C5—C6—C1	107.90 (16)	C13—C14—H14A	109.5
C12—C6—C1	114.38 (18)	C13—C14—H14B	109.5
C8—C7—C6	113.48 (17)	H14A—C14—H14B	109.5
C8—C7—H7A	108.9	C13—C14—H14C	109.5
C6—C7—H7A	108.9	H14A—C14—H14C	109.5
C8—C7—H7B	108.9	H14B—C14—H14C	109.5
C6—C7—H7B	108.9	C2—O1—H2	113 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H2···O2^i	0.84 (3)	2.05 (3)	2.883 (2)	169 (3)

Symmetry code: (i) −x+1, y−1/2, −z+2.