Acta Cryst. (2011). E67, o237 [ doi:10.1107/S160053681005333X ]
The title compound, C23H31NO, was semisynthesized from isocostic acid, 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. The dihedral angle between the latter ring and its substituent is 83.6 (7)°.
In a flask was introduced a mixture of 500 mg (2.42 mmol), of 1 - (4a, 8-dimethyl-1, 2,3,4,4a,5,6,8 a-octahydro-naphthalen-2 -yl)-ethanone, 360 mg (2.42 mmol.) of 4-dimethylamino-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 (98:2) as eluent of the residue allowed us to obtain 3-(4-dimethylamino-phenyl)(4a,8-dimethyl-1,2, 3,4,4a,5,6,8a-octahydro-naphthalene-2-yl)-propene-1-one with a yield of 80%. The title compound is recrystallized in hexane-ethyl acetate (95/5).
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 Uiso(H) = 1.2Ueq(methylene, methine and OH) or Uiso(H) = 1.5Ueq(methyl). In the absence of significant anomalous scattering, the absolute configuration could not be reliably determined and thus 1783 Friedel pairs were merged and any references to the Flack parameter were removed.
Data collection: CrysAlis PRO (Oxford Diffraction, 2010); cell refinement: CrysAlis PRO (Oxford Diffraction, 2010); data reduction: CrysAlis PRO (Oxford Diffraction, 2010); 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).
![[Figure 1]](./fj2378fig1thm.gif)
| 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. |
| C23H31NO | F(000) = 368 |
| Mr = 337.49 | Dx = 1.173 Mg m−3 |
| Monoclinic, P21 | Mo Kα radiation, λ = 0.71073 Å |
| Hall symbol: P 2yb | Cell parameters from 4058 reflections |
| a = 6.0593 (4) Å | θ = 3.0–28.5° |
| b = 7.2095 (7) Å | µ = 0.07 mm−1 |
| c = 21.8937 (19) Å | T = 298 K |
| β = 91.860 (7)° | Prism, colourless |
| V = 955.91 (14) Å3 | 0.6 × 0.25 × 0.10 mm |
| Z = 2 |
| Oxford Diffraction Xcalibur Eos Gemini ultra diffractometer | 1894 reflections with I > 2σ(I) |
| Radiation source: fine-focus sealed tube | Rint = 0.028 |
| graphite | θmax = 26.4°, θmin = 3.0° |
| Detector resolution: 16.1978 pixels mm-1 | h = −7→7 |
| φ and ω scans | k = −9→7 |
| 8394 measured reflections | l = −27→27 |
| 2112 independent reflections |
| Refinement on F2 | Primary atom site location: structure-invariant direct methods |
| Least-squares matrix: full | Secondary atom site location: difference Fourier map |
| R[F2 > 2σ(F2)] = 0.033 | Hydrogen site location: inferred from neighbouring sites |
| wR(F2) = 0.089 | H-atom parameters constrained |
| S = 1.05 | w = 1/[σ2(Fo2) + (0.056P)2 + 0.0652P] where P = (Fo2 + 2Fc2)/3 |
| 2112 reflections | (Δ/σ)max = 0.002 |
| 230 parameters | Δρmax = 0.21 e Å−3 |
| 1 restraint | Δρmin = −0.15 e Å−3 |
| C23H31NO | V = 955.91 (14) Å3 |
| Mr = 337.49 | Z = 2 |
| Monoclinic, P21 | Mo Kα radiation |
| a = 6.0593 (4) Å | µ = 0.07 mm−1 |
| b = 7.2095 (7) Å | T = 298 K |
| c = 21.8937 (19) Å | 0.6 × 0.25 × 0.10 mm |
| β = 91.860 (7)° |
| Oxford Diffraction Xcalibur Eos Gemini ultra diffractometer | 1894 reflections with I > 2σ(I) |
| 8394 measured reflections | Rint = 0.028 |
| 2112 independent reflections | θmax = 26.4° |
| R[F2 > 2σ(F2)] = 0.033 | H-atom parameters constrained |
| wR(F2) = 0.089 | Δρmax = 0.21 e Å−3 |
| S = 1.05 | Δρmin = −0.15 e Å−3 |
| 2112 reflections | Absolute structure: ? |
| 230 parameters | Flack parameter: ? |
| 1 restraint | Rogers parameter: ? |
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. |
| x | y | z | Uiso*/Ueq | ||
| C1 | 0.7303 (3) | 0.8137 (3) | 1.01854 (8) | 0.0250 (4) | |
| C2 | 0.9300 (3) | 0.7287 (3) | 1.00424 (8) | 0.0278 (4) | |
| H2 | 1.0181 | 0.6768 | 1.0353 | 0.033* | |
| C3 | 0.9978 (3) | 0.7208 (3) | 0.94506 (8) | 0.0280 (4) | |
| H3 | 1.1328 | 0.6656 | 0.9373 | 0.034* | |
| C4 | 0.8718 (3) | 0.7923 (2) | 0.89613 (8) | 0.0263 (4) | |
| C5 | 0.6725 (3) | 0.8750 (3) | 0.91030 (8) | 0.0287 (4) | |
| H5 | 0.5835 | 0.9236 | 0.8788 | 0.034* | |
| C6 | 0.6025 (3) | 0.8873 (3) | 0.96950 (8) | 0.0281 (4) | |
| H6 | 0.4689 | 0.9450 | 0.9771 | 0.034* | |
| C7 | 0.9359 (3) | 0.7711 (3) | 0.83304 (8) | 0.0295 (4) | |
| H7 | 0.8257 | 0.7832 | 0.8027 | 0.035* | |
| C8 | 1.1400 (3) | 0.7357 (3) | 0.81514 (9) | 0.0345 (4) | |
| H8 | 1.2509 | 0.7321 | 0.8455 | 0.041* | |
| C9 | 1.2066 (3) | 0.7020 (3) | 0.75226 (9) | 0.0371 (5) | |
| C10 | 1.0332 (3) | 0.6566 (3) | 0.70325 (8) | 0.0321 (4) | |
| H10 | 0.9057 | 0.7376 | 0.7089 | 0.038* | |
| C11 | 1.1144 (4) | 0.6858 (3) | 0.63863 (9) | 0.0422 (5) | |
| H11A | 1.1362 | 0.8174 | 0.6317 | 0.051* | |
| H11B | 1.2556 | 0.6244 | 0.6348 | 0.051* | |
| C12 | 0.9521 (4) | 0.6105 (3) | 0.59038 (8) | 0.0407 (5) | |
| H12A | 0.8182 | 0.6843 | 0.5905 | 0.049* | |
| H12B | 1.0155 | 0.6235 | 0.5505 | 0.049* | |
| C13 | 0.8930 (3) | 0.4083 (3) | 0.60040 (8) | 0.0299 (4) | |
| C14 | 0.7155 (3) | 0.3441 (4) | 0.55361 (8) | 0.0396 (5) | |
| H14A | 0.5853 | 0.4212 | 0.5571 | 0.048* | |
| H14B | 0.7699 | 0.3597 | 0.5127 | 0.048* | |
| C15 | 0.6526 (3) | 0.1432 (4) | 0.56287 (9) | 0.0458 (6) | |
| H15A | 0.5140 | 0.1185 | 0.5410 | 0.055* | |
| H15B | 0.7646 | 0.0643 | 0.5457 | 0.055* | |
| C16 | 0.6295 (3) | 0.0958 (3) | 0.62862 (9) | 0.0408 (5) | |
| H16 | 0.5651 | −0.0174 | 0.6379 | 0.049* | |
| C17 | 0.6948 (3) | 0.2044 (3) | 0.67505 (8) | 0.0317 (4) | |
| C18 | 0.7946 (3) | 0.3924 (3) | 0.66407 (7) | 0.0265 (4) | |
| H18 | 0.6723 | 0.4812 | 0.6646 | 0.032* | |
| C19 | 0.9605 (3) | 0.4550 (3) | 0.71385 (8) | 0.0290 (4) | |
| H19A | 1.0886 | 0.3744 | 0.7140 | 0.035* | |
| H19B | 0.8940 | 0.4452 | 0.7534 | 0.035* | |
| C20 | 1.0979 (3) | 0.2867 (3) | 0.59410 (9) | 0.0393 (5) | |
| H20A | 1.0624 | 0.1607 | 0.6040 | 0.059* | |
| H20B | 1.2134 | 0.3303 | 0.6215 | 0.059* | |
| H20C | 1.1466 | 0.2929 | 0.5529 | 0.059* | |
| C21 | 0.6499 (4) | 0.1524 (4) | 0.73956 (10) | 0.0524 (6) | |
| H21A | 0.5633 | 0.0409 | 0.7399 | 0.079* | |
| H21B | 0.5703 | 0.2508 | 0.7586 | 0.079* | |
| H21C | 0.7871 | 0.1321 | 0.7617 | 0.079* | |
| C22 | 0.8030 (3) | 0.7487 (3) | 1.12674 (9) | 0.0393 (5) | |
| H22A | 0.8180 | 0.6174 | 1.1209 | 0.059* | |
| H22B | 0.7360 | 0.7719 | 1.1651 | 0.059* | |
| H22C | 0.9462 | 0.8058 | 1.1267 | 0.059* | |
| C23 | 0.4516 (3) | 0.8908 (3) | 1.09306 (9) | 0.0374 (5) | |
| H23A | 0.3430 | 0.7989 | 1.0819 | 0.056* | |
| H23B | 0.4199 | 1.0037 | 1.0712 | 0.056* | |
| H23C | 0.4482 | 0.9137 | 1.1362 | 0.056* | |
| N1 | 0.6663 (2) | 0.8252 (2) | 1.07791 (7) | 0.0325 (4) | |
| O1 | 1.4040 (2) | 0.6982 (3) | 0.74180 (8) | 0.0544 (5) |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| C1 | 0.0224 (7) | 0.0172 (9) | 0.0354 (8) | −0.0036 (7) | −0.0016 (6) | −0.0015 (7) |
| C2 | 0.0252 (8) | 0.0228 (10) | 0.0352 (9) | 0.0016 (8) | −0.0042 (7) | 0.0000 (8) |
| C3 | 0.0235 (7) | 0.0214 (10) | 0.0389 (9) | 0.0023 (7) | 0.0001 (7) | −0.0031 (8) |
| C4 | 0.0273 (8) | 0.0171 (10) | 0.0342 (9) | −0.0033 (7) | −0.0014 (7) | −0.0016 (7) |
| C5 | 0.0267 (8) | 0.0229 (10) | 0.0361 (9) | −0.0011 (7) | −0.0059 (7) | 0.0015 (8) |
| C6 | 0.0230 (7) | 0.0206 (9) | 0.0406 (10) | 0.0026 (7) | −0.0027 (7) | −0.0002 (8) |
| C7 | 0.0353 (9) | 0.0189 (10) | 0.0339 (9) | −0.0044 (7) | −0.0025 (7) | −0.0009 (7) |
| C8 | 0.0334 (9) | 0.0317 (11) | 0.0382 (10) | −0.0077 (9) | −0.0016 (7) | −0.0066 (8) |
| C9 | 0.0374 (9) | 0.0279 (11) | 0.0463 (11) | −0.0089 (9) | 0.0073 (8) | −0.0057 (9) |
| C10 | 0.0379 (9) | 0.0269 (11) | 0.0318 (9) | −0.0051 (8) | 0.0072 (7) | −0.0005 (8) |
| C11 | 0.0544 (12) | 0.0335 (12) | 0.0396 (10) | −0.0104 (10) | 0.0152 (9) | 0.0056 (9) |
| C12 | 0.0547 (11) | 0.0415 (13) | 0.0267 (9) | 0.0020 (10) | 0.0115 (8) | 0.0086 (9) |
| C13 | 0.0314 (8) | 0.0349 (11) | 0.0237 (8) | 0.0046 (8) | 0.0054 (7) | −0.0005 (8) |
| C14 | 0.0383 (10) | 0.0566 (15) | 0.0239 (8) | 0.0093 (10) | 0.0009 (7) | −0.0053 (9) |
| C15 | 0.0403 (11) | 0.0575 (15) | 0.0395 (10) | −0.0011 (11) | −0.0006 (8) | −0.0215 (10) |
| C16 | 0.0335 (9) | 0.0391 (13) | 0.0499 (11) | −0.0039 (9) | 0.0004 (8) | −0.0091 (10) |
| C17 | 0.0278 (8) | 0.0328 (11) | 0.0346 (9) | −0.0028 (8) | 0.0021 (7) | −0.0024 (8) |
| C18 | 0.0271 (8) | 0.0292 (10) | 0.0233 (8) | 0.0029 (8) | 0.0036 (6) | −0.0010 (7) |
| C19 | 0.0349 (9) | 0.0278 (10) | 0.0244 (8) | −0.0059 (8) | 0.0027 (7) | 0.0008 (7) |
| C20 | 0.0306 (9) | 0.0467 (14) | 0.0410 (10) | 0.0038 (9) | 0.0069 (8) | −0.0074 (9) |
| C21 | 0.0661 (14) | 0.0480 (15) | 0.0433 (11) | −0.0277 (13) | 0.0041 (10) | 0.0073 (11) |
| C22 | 0.0369 (9) | 0.0459 (14) | 0.0350 (9) | 0.0075 (10) | 0.0017 (7) | 0.0030 (9) |
| C23 | 0.0329 (9) | 0.0344 (11) | 0.0452 (11) | 0.0081 (9) | 0.0050 (8) | −0.0013 (9) |
| N1 | 0.0264 (7) | 0.0366 (10) | 0.0347 (8) | 0.0037 (7) | 0.0020 (6) | 0.0032 (7) |
| O1 | 0.0352 (7) | 0.0667 (12) | 0.0619 (9) | −0.0137 (8) | 0.0125 (7) | −0.0192 (9) |
| C1—N1 | 1.371 (2) | C13—C18 | 1.538 (2) |
| C1—C2 | 1.401 (2) | C14—C15 | 1.513 (4) |
| C1—C6 | 1.407 (2) | C14—H14A | 0.9700 |
| C2—C3 | 1.373 (2) | C14—H14B | 0.9700 |
| C2—H2 | 0.9300 | C15—C16 | 1.490 (3) |
| C3—C4 | 1.394 (2) | C15—H15A | 0.9700 |
| C3—H3 | 0.9300 | C15—H15B | 0.9700 |
| C4—C5 | 1.390 (2) | C16—C17 | 1.333 (3) |
| C4—C7 | 1.455 (2) | C16—H16 | 0.9300 |
| C5—C6 | 1.380 (2) | C17—C21 | 1.495 (3) |
| C5—H5 | 0.9300 | C17—C18 | 1.507 (3) |
| C6—H6 | 0.9300 | C18—C19 | 1.527 (2) |
| C7—C8 | 1.334 (3) | C18—H18 | 0.9800 |
| C7—H7 | 0.9300 | C19—H19A | 0.9700 |
| C8—C9 | 1.467 (3) | C19—H19B | 0.9700 |
| C8—H8 | 0.9300 | C20—H20A | 0.9600 |
| C9—O1 | 1.226 (2) | C20—H20B | 0.9600 |
| C9—C10 | 1.513 (3) | C20—H20C | 0.9600 |
| C10—C11 | 1.527 (2) | C21—H21A | 0.9600 |
| C10—C19 | 1.538 (3) | C21—H21B | 0.9600 |
| C10—H10 | 0.9800 | C21—H21C | 0.9600 |
| C11—C12 | 1.520 (3) | C22—N1 | 1.441 (2) |
| C11—H11A | 0.9700 | C22—H22A | 0.9600 |
| C11—H11B | 0.9700 | C22—H22B | 0.9600 |
| C12—C13 | 1.519 (3) | C22—H22C | 0.9600 |
| C12—H12A | 0.9700 | C23—N1 | 1.433 (2) |
| C12—H12B | 0.9700 | C23—H23A | 0.9600 |
| C13—C20 | 1.530 (3) | C23—H23B | 0.9600 |
| C13—C14 | 1.533 (2) | C23—H23C | 0.9600 |
| N1—C1—C2 | 120.75 (15) | C15—C14—H14B | 109.2 |
| N1—C1—C6 | 122.33 (15) | C13—C14—H14B | 109.2 |
| C2—C1—C6 | 116.91 (15) | H14A—C14—H14B | 107.9 |
| C3—C2—C1 | 121.08 (16) | C16—C15—C14 | 112.40 (17) |
| C3—C2—H2 | 119.5 | C16—C15—H15A | 109.1 |
| C1—C2—H2 | 119.5 | C14—C15—H15A | 109.1 |
| C2—C3—C4 | 122.42 (16) | C16—C15—H15B | 109.1 |
| C2—C3—H3 | 118.8 | C14—C15—H15B | 109.1 |
| C4—C3—H3 | 118.8 | H15A—C15—H15B | 107.9 |
| C5—C4—C3 | 116.43 (16) | C17—C16—C15 | 124.5 (2) |
| C5—C4—C7 | 121.17 (15) | C17—C16—H16 | 117.7 |
| C3—C4—C7 | 122.26 (16) | C15—C16—H16 | 117.7 |
| C6—C5—C4 | 122.21 (16) | C16—C17—C21 | 120.97 (19) |
| C6—C5—H5 | 118.9 | C16—C17—C18 | 121.17 (17) |
| C4—C5—H5 | 118.9 | C21—C17—C18 | 117.56 (17) |
| C5—C6—C1 | 120.93 (16) | C17—C18—C19 | 114.25 (15) |
| C5—C6—H6 | 119.5 | C17—C18—C13 | 112.40 (15) |
| C1—C6—H6 | 119.5 | C19—C18—C13 | 111.05 (13) |
| C8—C7—C4 | 125.31 (16) | C17—C18—H18 | 106.2 |
| C8—C7—H7 | 117.3 | C19—C18—H18 | 106.2 |
| C4—C7—H7 | 117.3 | C13—C18—H18 | 106.2 |
| C7—C8—C9 | 126.40 (17) | C18—C19—C10 | 110.91 (16) |
| C7—C8—H8 | 116.8 | C18—C19—H19A | 109.5 |
| C9—C8—H8 | 116.8 | C10—C19—H19A | 109.5 |
| O1—C9—C8 | 118.61 (18) | C18—C19—H19B | 109.5 |
| O1—C9—C10 | 121.48 (17) | C10—C19—H19B | 109.5 |
| C8—C9—C10 | 119.69 (16) | H19A—C19—H19B | 108.0 |
| C9—C10—C11 | 112.96 (16) | C13—C20—H20A | 109.5 |
| C9—C10—C19 | 107.05 (17) | C13—C20—H20B | 109.5 |
| C11—C10—C19 | 111.88 (16) | H20A—C20—H20B | 109.5 |
| C9—C10—H10 | 108.3 | C13—C20—H20C | 109.5 |
| C11—C10—H10 | 108.3 | H20A—C20—H20C | 109.5 |
| C19—C10—H10 | 108.3 | H20B—C20—H20C | 109.5 |
| C12—C11—C10 | 111.96 (16) | C17—C21—H21A | 109.5 |
| C12—C11—H11A | 109.2 | C17—C21—H21B | 109.5 |
| C10—C11—H11A | 109.2 | H21A—C21—H21B | 109.5 |
| C12—C11—H11B | 109.2 | C17—C21—H21C | 109.5 |
| C10—C11—H11B | 109.2 | H21A—C21—H21C | 109.5 |
| H11A—C11—H11B | 107.9 | H21B—C21—H21C | 109.5 |
| C13—C12—C11 | 113.12 (17) | N1—C22—H22A | 109.5 |
| C13—C12—H12A | 109.0 | N1—C22—H22B | 109.5 |
| C11—C12—H12A | 109.0 | H22A—C22—H22B | 109.5 |
| C13—C12—H12B | 109.0 | N1—C22—H22C | 109.5 |
| C11—C12—H12B | 109.0 | H22A—C22—H22C | 109.5 |
| H12A—C12—H12B | 107.8 | H22B—C22—H22C | 109.5 |
| C12—C13—C20 | 109.95 (17) | N1—C23—H23A | 109.5 |
| C12—C13—C14 | 110.92 (17) | N1—C23—H23B | 109.5 |
| C20—C13—C14 | 108.71 (16) | H23A—C23—H23B | 109.5 |
| C12—C13—C18 | 107.62 (15) | N1—C23—H23C | 109.5 |
| C20—C13—C18 | 112.25 (15) | H23A—C23—H23C | 109.5 |
| C14—C13—C18 | 107.38 (14) | H23B—C23—H23C | 109.5 |
| C15—C14—C13 | 111.95 (18) | C1—N1—C23 | 121.75 (15) |
| C15—C14—H14A | 109.2 | C1—N1—C22 | 120.44 (15) |
| C13—C14—H14A | 109.2 | C23—N1—C22 | 117.33 (15) |
The authors thank the Unit of Support for Technical and Scientific Research (UATRS, CNRST) for the X-ray measurements.
Azoulay, P., Reynier, J. P., Balansard, G., Gasquet, M. & Timon-David, P. (1986). Pharm. Acta Helv. 61, 345–352.
Bohlman, F. & Gupta, R. K. (1982). Phytochemistry, 21, 1443–1445.
Bohlmann, F., Czerson, H. & Schoneweib, S. (1977). Chem. Ber. 110, 1330–, 1334.
Ceccherelli, P., Curini, M. & Marcotullio, M. C. (1988). J. Nat. Prod. 51, 1006–1009.
Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354–1358.
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838.
Kutney, J. P. & Singh, A. (1984). Can. J. Chem. 62, 1407–1409.
Oxford Diffraction (2010). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Yarnton, England.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
Shtacher, G. & Kasshman, Y. (1970). J. Med. Chem. 13, 1221–1223.
Our work lies within the framework of the valorization of medicinals plants and concerning 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; Bohlman & Gupta, 1982) and has 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), 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 article 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, 8-dimethyl-1, 2,3,4,4 a, 5,6,8 a-octahydro- naphthalen-2-yl)-ethanone which was synthesized by Kutney et al.(1984). The Condensation of this ketone with 4-dimethylamino-benzaldehyde in the presence of sodium hydroxide allows us to obtain the title compound 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 is built up from two fused six-membered rings, substituted by 4-dimethyl-amino-phenylpropanoyl. The molecular structure of (I),Fig.1, shows the cyclohexene ring to adopt a half chair conformation as indicated by the total puckering amplitude Q(T)= 0.506 (2)Å and spherical polar angle θ = 48.8 (2)° with φ = 18.5 (3)°. By contrast the cyclohexane ring has a chair conformation with Q(T)= 0.574 (2)Å and spherical polar angle θ = 173.9 (2)° with φ = 28.6 (18)° (Cremer and Pople,1975).