organic compounds
2-{(1S,2S,4aR,8R,8aR)-8-Hydroxy-4a,8-dimethyl-1-[(2E)-2-methylbut-2-enoyloxy]perhydronaphthalen-2-yl}acrylic acid from Sclerorhachis platyrachis
aDepartment of Chemistry, Shahid Beheshti University, General Campus, Tehran, Iran, bDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia, and cChemistry Department, Faculty of Science, King Abdulaziz University, PO Box 80203 Jeddah, Saudi Arabia
*Correspondence e-mail: seikweng@um.edu.my
The eudesmane-type terpenoid, C20H30O5, isolated from Sclerorhachis platyrachis, has a decalin skeleton whose six-membered rings adopt chair conformations. The two methyl substituents occupy axial positions, whereas the other three substituents occupy equatorial positions. The hydroxy group is an intramolecular hydrogen-bond donor to the single-bond ester O atom; adjacent molecules are linked through the carboxylic acid interacting with the hydroxyl group, forming a hydrogen-bonded chain running along the c axis.
Related literature
For the et al. (1986). For a review of eudesmane-type see: Wu et al. (2006).
of epiilic acid, see: DaniewskiExperimental
Crystal data
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Data collection: CrysAlis PRO (Agilent, 2010); cell CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).
Supporting information
https://doi.org/10.1107/S1600536811037640/jh2330sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536811037640/jh2330Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S1600536811037640/jh2330Isup3.cml
The leaves and stems of Sclerorhachis platyrachis (Compositae family) were collected from Sabzevar, Khorasan Razavi Province, Iran, at the flowering stage of the plant, i.e., around May. The aerial parts were dried in the shade. The aerial parts (300 g) were extracted with chloroform by maceration at room temperature. The extract was concentrated to a green gummy extract (16 g). The extract was subjected to
on silica gel (4×70 cm, 70–230 mesh) with a gradient of n-hexane–ethyl acetate and then methanol as Eighty-three fractions were collected according to TLC analysis and those giving similar spots were combined. Fraction 51 (n-hexane: ethylacetate 4:1) afforded colorless crystals of the title compound (500 mg).Carbon-bound H-atoms were placed in calculated positions [C—H 0.95 to 0.98 Å, Uiso(H) 1.2 to 1.5Ueq(C)] and were included in the
in the riding model approximation.The carboxylic and hydroxy H-atoms were located in a difference Fourier map, and were freely refined.
Eudesmane-type of
(from the Asteraceae family) have been reviewed; some structural assignments and stereochemistries have also revised; however, the title compound (Scheme I) is not included in the review (Wu et al., 2006). The compound is a derivative of epiilic (vachanic) acid having a 1-(2-methylbut-2-enoyloxy) substitutent. The of the parent acid itself, which was first isolated from Dittrichia vicossa (L.), has been reported (Daniewski et al., 186). The two methyl substituents occupy axial positions whereas the other three substituents occupy equatorial positions (Fig 1). The hydroxy group is an intramolecular hydrogen-bond donor to the single-bond ester O atom; adjacent molecules are linked through the carboxylic acid portion to form a hydrogen-bonded chain running along the c-axis of the monoclinic (Table 1).For the
of epiilic acid, see: Daniewski et al. (1986). For a review of eudesmane-type see: Wu et al. (2006).Data collection: CrysAlis PRO (Agilent, 2010); cell
CrysAlis PRO (Agilent, 2010); data reduction: CrysAlis PRO (Agilent, 2010); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).Fig. 1. Thermal ellipsoid plot (Barbour, 2001) of C20H30O5 at the 70% probability level; hydrogen atoms are drawn as spheres of arbitrary radius. | |
Fig. 2. Hydrogen-bonded chain structure. |
C20H30O5 | F(000) = 380 |
Mr = 350.44 | Dx = 1.229 Mg m−3 |
Monoclinic, P21 | Cu Kα radiation, λ = 1.54184 Å |
Hall symbol: P 2yb | Cell parameters from 4968 reflections |
a = 6.2718 (1) Å | θ = 5.6–74.1° |
b = 19.0285 (3) Å | µ = 0.71 mm−1 |
c = 8.4530 (2) Å | T = 100 K |
β = 110.184 (2)° | Prism, colourless |
V = 946.85 (3) Å3 | 0.20 × 0.20 × 0.20 mm |
Z = 2 |
Agilent SuperNova Dual diffractometer with an Atlas detector | 3663 independent reflections |
Radiation source: SuperNova (Cu) X-ray Source | 3635 reflections with I > 2σ(I) |
Mirror monochromator | Rint = 0.015 |
Detector resolution: 10.4041 pixels mm-1 | θmax = 74.2°, θmin = 5.6° |
ω scans | h = −6→7 |
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010) | k = −23→22 |
Tmin = 0.872, Tmax = 0.872 | l = −10→10 |
5962 measured reflections |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.028 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.076 | w = 1/[σ2(Fo2) + (0.0493P)2 + 0.1079P] where P = (Fo2 + 2Fc2)/3 |
S = 1.03 | (Δ/σ)max = 0.001 |
3663 reflections | Δρmax = 0.19 e Å−3 |
238 parameters | Δρmin = −0.13 e Å−3 |
1 restraint | Absolute structure: Flack (1983), 1705 Friedel pairs |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.08 (11) |
C20H30O5 | V = 946.85 (3) Å3 |
Mr = 350.44 | Z = 2 |
Monoclinic, P21 | Cu Kα radiation |
a = 6.2718 (1) Å | µ = 0.71 mm−1 |
b = 19.0285 (3) Å | T = 100 K |
c = 8.4530 (2) Å | 0.20 × 0.20 × 0.20 mm |
β = 110.184 (2)° |
Agilent SuperNova Dual diffractometer with an Atlas detector | 3663 independent reflections |
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010) | 3635 reflections with I > 2σ(I) |
Tmin = 0.872, Tmax = 0.872 | Rint = 0.015 |
5962 measured reflections |
R[F2 > 2σ(F2)] = 0.028 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.076 | Δρmax = 0.19 e Å−3 |
S = 1.03 | Δρmin = −0.13 e Å−3 |
3663 reflections | Absolute structure: Flack (1983), 1705 Friedel pairs |
238 parameters | Absolute structure parameter: 0.08 (11) |
1 restraint |
x | y | z | Uiso*/Ueq | ||
O1 | 0.94364 (17) | 0.50094 (5) | 0.32350 (12) | 0.0229 (2) | |
O2 | 1.0317 (2) | 0.39226 (6) | 0.42340 (14) | 0.0337 (2) | |
O3 | 0.88724 (14) | 0.44178 (4) | −0.13924 (11) | 0.01664 (18) | |
O4 | 0.64080 (17) | 0.41443 (5) | −0.00727 (13) | 0.0264 (2) | |
O5 | 0.76555 (15) | 0.51072 (5) | −0.43525 (11) | 0.01914 (19) | |
C1 | 1.0458 (2) | 0.43922 (7) | 0.33077 (16) | 0.0212 (3) | |
C2 | 1.1838 (2) | 0.43410 (7) | 0.21712 (15) | 0.0190 (2) | |
C3 | 1.3138 (3) | 0.37790 (8) | 0.2342 (2) | 0.0305 (3) | |
H3A | 1.3167 | 0.3431 | 0.3155 | 0.037* | |
H3B | 1.4042 | 0.3723 | 0.1651 | 0.037* | |
C4 | 1.1868 (2) | 0.49268 (6) | 0.09608 (15) | 0.0170 (2) | |
H4 | 1.2901 | 0.4766 | 0.0358 | 0.020* | |
C5 | 1.2922 (2) | 0.56070 (7) | 0.19001 (15) | 0.0200 (3) | |
H5A | 1.2069 | 0.5752 | 0.2636 | 0.024* | |
H5B | 1.4512 | 0.5514 | 0.2626 | 0.024* | |
C6 | 1.2884 (2) | 0.62031 (7) | 0.06860 (16) | 0.0199 (3) | |
H6A | 1.3928 | 0.6086 | 0.0073 | 0.024* | |
H6B | 1.3454 | 0.6637 | 0.1342 | 0.024* | |
C7 | 1.0501 (2) | 0.63443 (6) | −0.06021 (15) | 0.0167 (2) | |
C8 | 0.8926 (2) | 0.65941 (7) | 0.03410 (16) | 0.0205 (3) | |
H8A | 0.9591 | 0.7008 | 0.1024 | 0.031* | |
H8B | 0.8751 | 0.6217 | 0.1075 | 0.031* | |
H8C | 0.7435 | 0.6717 | −0.0477 | 0.031* | |
C9 | 1.0683 (2) | 0.69343 (7) | −0.17927 (17) | 0.0198 (3) | |
H9A | 1.1013 | 0.7383 | −0.1162 | 0.024* | |
H9B | 1.1968 | 0.6832 | −0.2182 | 0.024* | |
C10 | 0.8522 (2) | 0.70175 (7) | −0.33205 (16) | 0.0205 (3) | |
H10A | 0.7238 | 0.7141 | −0.2946 | 0.025* | |
H10B | 0.8720 | 0.7402 | −0.4047 | 0.025* | |
C11 | 0.8004 (2) | 0.63328 (7) | −0.43153 (15) | 0.0196 (3) | |
H11A | 0.9268 | 0.6226 | −0.4726 | 0.023* | |
H11B | 0.6611 | 0.6396 | −0.5313 | 0.023* | |
C12 | 0.7668 (2) | 0.57076 (7) | −0.32876 (14) | 0.0165 (2) | |
C13 | 0.5355 (2) | 0.57294 (7) | −0.30647 (15) | 0.0210 (3) | |
H13A | 0.5234 | 0.5336 | −0.2353 | 0.031* | |
H13B | 0.4151 | 0.5693 | −0.4169 | 0.031* | |
H13C | 0.5196 | 0.6173 | −0.2529 | 0.031* | |
C14 | 0.97307 (19) | 0.56460 (6) | −0.16172 (14) | 0.0150 (2) | |
H14 | 1.1038 | 0.5505 | −0.1968 | 0.018* | |
C15 | 0.95518 (19) | 0.50674 (6) | −0.04079 (14) | 0.0144 (2) | |
H15 | 0.8402 | 0.5198 | 0.0118 | 0.017* | |
C16 | 0.7264 (2) | 0.40082 (6) | −0.11125 (15) | 0.0178 (2) | |
C17 | 0.6621 (2) | 0.33936 (6) | −0.22701 (15) | 0.0172 (2) | |
C18 | 0.7910 (2) | 0.32087 (7) | −0.31761 (16) | 0.0196 (3) | |
H18 | 0.9227 | 0.3486 | −0.3021 | 0.024* | |
C19 | 0.7516 (2) | 0.26166 (7) | −0.44010 (17) | 0.0249 (3) | |
H19A | 0.8832 | 0.2301 | −0.4053 | 0.037* | |
H19B | 0.7301 | 0.2804 | −0.5526 | 0.037* | |
H19C | 0.6156 | 0.2356 | −0.4429 | 0.037* | |
C20 | 0.4449 (2) | 0.30420 (7) | −0.23055 (18) | 0.0249 (3) | |
H20A | 0.4210 | 0.2614 | −0.2990 | 0.037* | |
H20B | 0.3170 | 0.3364 | −0.2795 | 0.037* | |
H20C | 0.4556 | 0.2920 | −0.1154 | 0.037* | |
H1 | 0.881 (4) | 0.5016 (12) | 0.399 (3) | 0.053 (6)* | |
H5 | 0.787 (4) | 0.4729 (12) | −0.379 (3) | 0.041 (5)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0310 (5) | 0.0223 (5) | 0.0201 (4) | 0.0048 (4) | 0.0150 (4) | 0.0010 (4) |
O2 | 0.0468 (6) | 0.0291 (5) | 0.0353 (6) | 0.0089 (5) | 0.0270 (5) | 0.0130 (5) |
O3 | 0.0187 (4) | 0.0162 (4) | 0.0172 (4) | −0.0033 (3) | 0.0090 (3) | −0.0039 (3) |
O4 | 0.0302 (5) | 0.0262 (5) | 0.0305 (5) | −0.0080 (4) | 0.0205 (4) | −0.0073 (4) |
O5 | 0.0248 (5) | 0.0190 (5) | 0.0144 (4) | 0.0004 (4) | 0.0078 (3) | −0.0025 (4) |
C1 | 0.0245 (6) | 0.0220 (6) | 0.0178 (6) | 0.0016 (5) | 0.0082 (5) | 0.0016 (5) |
C2 | 0.0211 (5) | 0.0192 (6) | 0.0170 (5) | −0.0002 (5) | 0.0069 (4) | 0.0022 (5) |
C3 | 0.0377 (8) | 0.0240 (7) | 0.0382 (8) | 0.0084 (6) | 0.0238 (7) | 0.0095 (6) |
C4 | 0.0175 (6) | 0.0182 (6) | 0.0162 (5) | −0.0002 (4) | 0.0069 (5) | 0.0005 (5) |
C5 | 0.0199 (6) | 0.0217 (7) | 0.0153 (5) | −0.0035 (5) | 0.0019 (4) | 0.0003 (5) |
C6 | 0.0185 (6) | 0.0209 (6) | 0.0194 (6) | −0.0042 (5) | 0.0053 (5) | 0.0000 (5) |
C7 | 0.0186 (6) | 0.0156 (6) | 0.0159 (5) | −0.0025 (4) | 0.0058 (5) | −0.0017 (4) |
C8 | 0.0244 (6) | 0.0189 (6) | 0.0193 (6) | −0.0004 (5) | 0.0090 (5) | −0.0041 (5) |
C9 | 0.0218 (6) | 0.0169 (6) | 0.0214 (6) | −0.0017 (4) | 0.0083 (5) | 0.0003 (4) |
C10 | 0.0252 (6) | 0.0161 (6) | 0.0207 (6) | 0.0034 (5) | 0.0084 (5) | 0.0027 (5) |
C11 | 0.0220 (6) | 0.0212 (6) | 0.0150 (6) | 0.0017 (5) | 0.0057 (5) | 0.0010 (5) |
C12 | 0.0184 (6) | 0.0170 (6) | 0.0147 (5) | 0.0011 (5) | 0.0063 (4) | −0.0024 (5) |
C13 | 0.0166 (6) | 0.0269 (7) | 0.0189 (6) | 0.0014 (5) | 0.0054 (5) | −0.0025 (5) |
C14 | 0.0147 (5) | 0.0168 (6) | 0.0147 (5) | −0.0004 (4) | 0.0067 (4) | −0.0020 (5) |
C15 | 0.0167 (6) | 0.0133 (5) | 0.0141 (5) | −0.0008 (4) | 0.0065 (4) | −0.0027 (4) |
C16 | 0.0161 (5) | 0.0196 (6) | 0.0186 (6) | −0.0007 (4) | 0.0072 (4) | 0.0017 (5) |
C17 | 0.0166 (5) | 0.0157 (6) | 0.0182 (5) | −0.0002 (4) | 0.0045 (4) | 0.0013 (4) |
C18 | 0.0186 (6) | 0.0196 (6) | 0.0197 (6) | −0.0010 (5) | 0.0054 (5) | −0.0006 (5) |
C19 | 0.0265 (6) | 0.0251 (7) | 0.0232 (7) | −0.0012 (5) | 0.0088 (5) | −0.0056 (5) |
C20 | 0.0199 (6) | 0.0232 (7) | 0.0333 (7) | −0.0044 (5) | 0.0113 (5) | −0.0041 (5) |
O1—C1 | 1.3290 (16) | C9—C10 | 1.5236 (18) |
O1—H1 | 0.85 (2) | C9—H9A | 0.9900 |
O2—C1 | 1.2113 (16) | C9—H9B | 0.9900 |
O3—C16 | 1.3586 (15) | C10—C11 | 1.5237 (18) |
O3—C15 | 1.4689 (13) | C10—H10A | 0.9900 |
O4—C16 | 1.2056 (16) | C10—H10B | 0.9900 |
O5—C12 | 1.4530 (14) | C11—C12 | 1.5297 (17) |
O5—H5 | 0.85 (2) | C11—H11A | 0.9900 |
C1—C2 | 1.5021 (17) | C11—H11B | 0.9900 |
C2—C3 | 1.322 (2) | C12—C13 | 1.5265 (16) |
C2—C4 | 1.5175 (16) | C12—C14 | 1.5559 (15) |
C3—H3A | 0.9500 | C13—H13A | 0.9800 |
C3—H3B | 0.9500 | C13—H13B | 0.9800 |
C4—C15 | 1.5365 (15) | C13—H13C | 0.9800 |
C4—C5 | 1.5429 (17) | C14—C15 | 1.5325 (16) |
C4—H4 | 1.0000 | C14—H14 | 1.0000 |
C5—C6 | 1.5245 (17) | C15—H15 | 1.0000 |
C5—H5A | 0.9900 | C16—C17 | 1.4885 (16) |
C5—H5B | 0.9900 | C17—C18 | 1.3388 (18) |
C6—C7 | 1.5394 (17) | C17—C20 | 1.5083 (17) |
C6—H6A | 0.9900 | C18—C19 | 1.4920 (17) |
C6—H6B | 0.9900 | C18—H18 | 0.9500 |
C7—C9 | 1.5380 (17) | C19—H19A | 0.9800 |
C7—C8 | 1.5428 (17) | C19—H19B | 0.9800 |
C7—C14 | 1.5650 (16) | C19—H19C | 0.9800 |
C8—H8A | 0.9800 | C20—H20A | 0.9800 |
C8—H8B | 0.9800 | C20—H20B | 0.9800 |
C8—H8C | 0.9800 | C20—H20C | 0.9800 |
C1—O1—H1 | 108.4 (15) | H10A—C10—H10B | 108.2 |
C16—O3—C15 | 118.15 (9) | C10—C11—C12 | 113.36 (10) |
C12—O5—H5 | 110.5 (14) | C10—C11—H11A | 108.9 |
O2—C1—O1 | 122.71 (12) | C12—C11—H11A | 108.9 |
O2—C1—C2 | 123.53 (12) | C10—C11—H11B | 108.9 |
O1—C1—C2 | 113.74 (11) | C12—C11—H11B | 108.9 |
C3—C2—C1 | 116.90 (12) | H11A—C11—H11B | 107.7 |
C3—C2—C4 | 121.14 (12) | O5—C12—C13 | 107.20 (10) |
C1—C2—C4 | 121.84 (11) | O5—C12—C11 | 103.42 (9) |
C2—C3—H3A | 120.0 | C13—C12—C11 | 111.83 (11) |
C2—C3—H3B | 120.0 | O5—C12—C14 | 109.15 (9) |
H3A—C3—H3B | 120.0 | C13—C12—C14 | 114.71 (9) |
C2—C4—C15 | 114.03 (10) | C11—C12—C14 | 109.86 (10) |
C2—C4—C5 | 111.84 (10) | C12—C13—H13A | 109.5 |
C15—C4—C5 | 111.54 (10) | C12—C13—H13B | 109.5 |
C2—C4—H4 | 106.3 | H13A—C13—H13B | 109.5 |
C15—C4—H4 | 106.3 | C12—C13—H13C | 109.5 |
C5—C4—H4 | 106.3 | H13A—C13—H13C | 109.5 |
C6—C5—C4 | 111.93 (10) | H13B—C13—H13C | 109.5 |
C6—C5—H5A | 109.2 | C15—C14—C12 | 115.48 (9) |
C4—C5—H5A | 109.2 | C15—C14—C7 | 108.91 (9) |
C6—C5—H5B | 109.2 | C12—C14—C7 | 115.86 (10) |
C4—C5—H5B | 109.2 | C15—C14—H14 | 105.1 |
H5A—C5—H5B | 107.9 | C12—C14—H14 | 105.1 |
C5—C6—C7 | 113.06 (10) | C7—C14—H14 | 105.1 |
C5—C6—H6A | 109.0 | O3—C15—C14 | 107.48 (8) |
C7—C6—H6A | 109.0 | O3—C15—C4 | 107.10 (9) |
C5—C6—H6B | 109.0 | C14—C15—C4 | 111.08 (9) |
C7—C6—H6B | 109.0 | O3—C15—H15 | 110.4 |
H6A—C6—H6B | 107.8 | C14—C15—H15 | 110.4 |
C6—C7—C9 | 108.48 (10) | C4—C15—H15 | 110.4 |
C6—C7—C8 | 109.08 (10) | O4—C16—O3 | 123.23 (11) |
C9—C7—C8 | 108.57 (10) | O4—C16—C17 | 124.06 (11) |
C6—C7—C14 | 106.28 (10) | O3—C16—C17 | 112.67 (10) |
C9—C7—C14 | 109.85 (9) | C18—C17—C16 | 120.16 (11) |
C8—C7—C14 | 114.42 (10) | C18—C17—C20 | 126.28 (12) |
C7—C8—H8A | 109.5 | C16—C17—C20 | 113.55 (11) |
C7—C8—H8B | 109.5 | C17—C18—C19 | 127.40 (12) |
H8A—C8—H8B | 109.5 | C17—C18—H18 | 116.3 |
C7—C8—H8C | 109.5 | C19—C18—H18 | 116.3 |
H8A—C8—H8C | 109.5 | C18—C19—H19A | 109.5 |
H8B—C8—H8C | 109.5 | C18—C19—H19B | 109.5 |
C10—C9—C7 | 112.67 (10) | H19A—C19—H19B | 109.5 |
C10—C9—H9A | 109.1 | C18—C19—H19C | 109.5 |
C7—C9—H9A | 109.1 | H19A—C19—H19C | 109.5 |
C10—C9—H9B | 109.1 | H19B—C19—H19C | 109.5 |
C7—C9—H9B | 109.1 | C17—C20—H20A | 109.5 |
H9A—C9—H9B | 107.8 | C17—C20—H20B | 109.5 |
C11—C10—C9 | 109.70 (10) | H20A—C20—H20B | 109.5 |
C11—C10—H10A | 109.7 | C17—C20—H20C | 109.5 |
C9—C10—H10A | 109.7 | H20A—C20—H20C | 109.5 |
C11—C10—H10B | 109.7 | H20B—C20—H20C | 109.5 |
C9—C10—H10B | 109.7 | ||
O2—C1—C2—C3 | −7.2 (2) | C13—C12—C14—C7 | −79.68 (14) |
O1—C1—C2—C3 | 171.30 (13) | C11—C12—C14—C7 | 47.30 (13) |
O2—C1—C2—C4 | 176.65 (13) | C6—C7—C14—C15 | 63.08 (12) |
O1—C1—C2—C4 | −4.81 (17) | C9—C7—C14—C15 | −179.76 (9) |
C3—C2—C4—C15 | 120.75 (14) | C8—C7—C14—C15 | −57.36 (13) |
C1—C2—C4—C15 | −63.31 (15) | C6—C7—C14—C12 | −164.75 (10) |
C3—C2—C4—C5 | −111.53 (15) | C9—C7—C14—C12 | −47.59 (13) |
C1—C2—C4—C5 | 64.41 (15) | C8—C7—C14—C12 | 74.81 (13) |
C2—C4—C5—C6 | −178.17 (10) | C16—O3—C15—C14 | −137.12 (10) |
C15—C4—C5—C6 | −49.13 (14) | C16—O3—C15—C4 | 103.46 (11) |
C4—C5—C6—C7 | 53.90 (14) | C12—C14—C15—O3 | 48.75 (12) |
C5—C6—C7—C9 | −178.02 (10) | C7—C14—C15—O3 | −178.88 (8) |
C5—C6—C7—C8 | 63.89 (13) | C12—C14—C15—C4 | 165.60 (9) |
C5—C6—C7—C14 | −59.95 (13) | C7—C14—C15—C4 | −62.02 (12) |
C6—C7—C9—C10 | 168.69 (10) | C2—C4—C15—O3 | −60.90 (12) |
C8—C7—C9—C10 | −72.89 (13) | C5—C4—C15—O3 | 171.23 (9) |
C14—C7—C9—C10 | 52.92 (13) | C2—C4—C15—C14 | −177.99 (10) |
C7—C9—C10—C11 | −59.35 (14) | C5—C4—C15—C14 | 54.14 (12) |
C9—C10—C11—C12 | 59.45 (14) | C15—O3—C16—O4 | −1.68 (17) |
C10—C11—C12—O5 | −169.09 (10) | C15—O3—C16—C17 | 176.10 (9) |
C10—C11—C12—C13 | 75.89 (13) | O4—C16—C17—C18 | −168.19 (13) |
C10—C11—C12—C14 | −52.68 (13) | O3—C16—C17—C18 | 14.06 (16) |
O5—C12—C14—C15 | −70.92 (12) | O4—C16—C17—C20 | 12.88 (18) |
C13—C12—C14—C15 | 49.37 (14) | O3—C16—C17—C20 | −164.88 (11) |
C11—C12—C14—C15 | 176.34 (9) | C16—C17—C18—C19 | −179.39 (12) |
O5—C12—C14—C7 | 160.04 (9) | C20—C17—C18—C19 | −0.6 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···O5i | 0.85 (2) | 1.80 (2) | 2.648 (1) | 174 (2) |
O5—H5···O3 | 0.85 (2) | 1.99 (2) | 2.692 (1) | 139 (2) |
Symmetry code: (i) x, y, z+1. |
Experimental details
Crystal data | |
Chemical formula | C20H30O5 |
Mr | 350.44 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 100 |
a, b, c (Å) | 6.2718 (1), 19.0285 (3), 8.4530 (2) |
β (°) | 110.184 (2) |
V (Å3) | 946.85 (3) |
Z | 2 |
Radiation type | Cu Kα |
µ (mm−1) | 0.71 |
Crystal size (mm) | 0.20 × 0.20 × 0.20 |
Data collection | |
Diffractometer | Agilent SuperNova Dual diffractometer with an Atlas detector |
Absorption correction | Multi-scan (CrysAlis PRO; Agilent, 2010) |
Tmin, Tmax | 0.872, 0.872 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5962, 3663, 3635 |
Rint | 0.015 |
(sin θ/λ)max (Å−1) | 0.624 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.028, 0.076, 1.03 |
No. of reflections | 3663 |
No. of parameters | 238 |
No. of restraints | 1 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.19, −0.13 |
Absolute structure | Flack (1983), 1705 Friedel pairs |
Absolute structure parameter | 0.08 (11) |
Computer programs: CrysAlis PRO (Agilent, 2010), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), X-SEED (Barbour, 2001), publCIF (Westrip, 2010).
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···O5i | 0.85 (2) | 1.80 (2) | 2.648 (1) | 174 (2) |
O5—H5···O3 | 0.85 (2) | 1.99 (2) | 2.692 (1) | 139 (2) |
Symmetry code: (i) x, y, z+1. |
Acknowledgements
The authors thank Shahid Beheshti University and the University of Malaya for supporting this study.
References
Agilent (2010). CrysAlis PRO. Agilent Technologies, Yarnton, Oxfordshire, England. Google Scholar
Barbour, L. J. (2001). J. Supramol. Chem. 1, 189–191. CrossRef CAS Google Scholar
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Eudesmane-type of sesquiterpenoids (from the Asteraceae family) have been reviewed; some structural assignments and stereochemistries have also revised; however, the title compound (Scheme I) is not included in the review (Wu et al., 2006). The compound is a derivative of epiilic (vachanic) acid having a 1-(2-methylbut-2-enoyloxy) substitutent. The crystal structure of the parent acid itself, which was first isolated from Dittrichia vicossa (L.), has been reported (Daniewski et al., 186). The two methyl substituents occupy axial positions whereas the other three substituents occupy equatorial positions (Fig 1). The hydroxy group is an intramolecular hydrogen-bond donor to the single-bond ester O atom; adjacent molecules are linked through the carboxylic acid portion to form a hydrogen-bonded chain running along the c-axis of the monoclinic unit cell (Table 1).