organic compounds
9α-Acetoxy-1β,10α-epoxyparthenolide
aLaboratoire de Chimie Bioorganique et Analytique, URAC 22, BP 146, FSTM, Université Hassan II, Mohammedia-Casablanca 20810 Mohammedia, Morocco, bLaboratoire de Chimie du Solide Appliquée, Faculté des Sciences, Avenue Ibn Battouta B.P. 1014 Rabat, Morocco, and cLaboratoire de Chimie des Substances Naturelles, URAC16, Faculté des Sciences Semlalia, BP 2390 Bd My Abdellah, 40000 Marrakech, Morocco
*Correspondence e-mail: makssira@gmail.com
The title compound, C17H22O6, was semi-synthesized from 9-hydroxyarthenolide, which was isolated from the chloroform extract of the aerial parts of Anvillea radiata. The molecule contains fused five- and ten-membered rings: the five-membered lactone ring has a twisted conformation, whereas the ten-membered ring displays an approximate chair–chair conformation. The dihedral angle between the rings is 24.76 (9)°.
Related literature
For the isolation of 9-hydroxyarthenolide, see: El Hassany et al. (2004); Abdel Sattar et al. (1996). For the reactivity of this sesquiterpene, see: Castaneda-Acosta et al. (1993); Neukirch et al. (2003). For its biological activity, see: Abdel Sattar et al. (1996). For ring puckering parameters, see: Cremer & Pople (1975). For conformations of ten-membered rings, see: Castaneda-Acosta et al. (1997); Watson & Zabel (1982); Moumou et al. (2010).
Experimental
Crystal data
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Data collection: APEX2 (Bruker, 2007); cell SAINT (Bruker, 2007); 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).
Supporting information
https://doi.org/10.1107/S1600536810047471/fj2367sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810047471/fj2367Isup2.hkl
To a solution of 1,2 g (4,54 mmol) of 9α-hydroxyparthenolide in 30 ml of pyridine was added 10 ml of acetic anhydride. The mixture is left stirring for 12 h at room temperature and then treated with 100 ml of ice water and extracted with chloroform. The residue obtained after drying and evaporation of solvent was chromatographed on silica gel eluting with hexane-ethyl acetate (80/20) and allowed to isolate in pure form with a yield qantitatif the 9α-acétoxyparthenolide. To 0.5 g (1,6 mmol) of this latter dissolved in 40 ml of dichloromethane is added an equivalent of acid meta chloroperbenzoïque (mCPBA). The reaction mixture was stirred at room temperature for 3 h, then treated with a solution of sodium bisulfite at 10% and extracted with dichloromethane. The organic phase is dried over sodium sulfate and then evaporated under vacuum. of the residue obtained on silica gel column eluting with hexane ethyl acetate (75/25), allowed us to obtain the 9α-Acetoxy-1β, 10α-epoxyparthenolide with a yield of 80%.Crystallization of this product was carried out at room temperature from an ethyl acetate solution.
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
the could not be reliably determined and thus 2417 Friedel pairs were merged and any references to the were removed.The Natural sesquiterpene lactone (9α-hydroxyparthenolide) is the main constituent of the chloroform extract of aerial parts of Anvillea radiata (El Hassany et al., 2004), and of Anvillea garcini(Abdel Sattar et al.,1996). The reactivity of this sesuiterpène and its derivatives has been the subject of several studies (Castaneda-Acosta et al.,1993; Neukirch et al., 2003), in order to prepare products with high value added, used in industrial pharmacology. In the same context, we carried out the acetylation followed by epoxydation of 9α-hydroxyparthenolide. Thus, the action of one equivalent of acetic anhydride on this sesquiterpene in pyridine at 0°C leads to quantitative yield 9α-acétoxyparthenolide. The treatment of this latter with one equivalent of meta-choroperbenzoïque acid (mCPBA) in dichloromethane at room temperature gives 9α-acetoxy-1β, 10β-epoxyparthenolide with a yield of 95%. The structure of this new product was determined by NMR spectral analysis of 1H, 13 C and and confirmed by a study of X ray crystallography. The structure of (I) was established by 1H and 13 C NMR and confirmed by its single-crystal X-ray structure.The molecule is built up from two fused five-and ten-membered rings.(Fig. 1). The five-membered ring adopts a twisted conformation,as indicated by Cremer & Pople (1975) puckering parameters Q = 0.26 (2) Å and φ = 23.77 (4)°. The ten-membered ring displays an approximate chair-chair conformation. This is the typical conformation observed for other sesquiterpenes (Moumou et al., 2010; Watson & Zabel, 1982; Castaneda-Acosta et al., 1997).
For the isolation of 9-hydroxyarthenolide, see: El Hassany et al. (2004); Abdel Sattar et al. (1996). For the reactivity of this sesquiterpene, see: Castaneda-Acosta et al. (1993); Neukirch et al. (2003). For its biological activity, see: Abdel Sattar et al. (1996). For ring puckering parameters, see: Cremer & Pople (1975). For conformations of ten-membered rings, see: Castaneda-Acosta et al. (1997); Watson & Zabel (1982); Moumou et al. (2010).
Data collection: APEX2 (Bruker, 2007); cell
SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); 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).C17H22O6 | F(000) = 344 |
Mr = 322.35 | Dx = 1.318 Mg m−3 |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2yb | Cell parameters from 12911 reflections |
a = 8.2390 (3) Å | θ = 2.2–31.0° |
b = 10.6482 (4) Å | µ = 0.10 mm−1 |
c = 9.4633 (3) Å | T = 298 K |
β = 102.039 (2)° | PRISM, colourless |
V = 811.96 (5) Å3 | 0.38 × 0.27 × 0.12 mm |
Z = 2 |
Bruker X8 APEX CCD area-detector diffractometer | 2480 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.023 |
Graphite monochromator | θmax = 31.1°, θmin = 2.2° |
φ and ω scans | h = −11→11 |
12911 measured reflections | k = −15→15 |
2718 independent reflections | l = −13→13 |
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)] = 0.038 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.115 | H-atom parameters constrained |
S = 1.05 | w = 1/[σ2(Fo2) + (0.0742P)2 + 0.0491P] where P = (Fo2 + 2Fc2)/3 |
2718 reflections | (Δ/σ)max < 0.001 |
211 parameters | Δρmax = 0.25 e Å−3 |
1 restraint | Δρmin = −0.17 e Å−3 |
C17H22O6 | V = 811.96 (5) Å3 |
Mr = 322.35 | Z = 2 |
Monoclinic, P21 | Mo Kα radiation |
a = 8.2390 (3) Å | µ = 0.10 mm−1 |
b = 10.6482 (4) Å | T = 298 K |
c = 9.4633 (3) Å | 0.38 × 0.27 × 0.12 mm |
β = 102.039 (2)° |
Bruker X8 APEX CCD area-detector diffractometer | 2480 reflections with I > 2σ(I) |
12911 measured reflections | Rint = 0.023 |
2718 independent reflections |
R[F2 > 2σ(F2)] = 0.038 | 1 restraint |
wR(F2) = 0.115 | H-atom parameters constrained |
S = 1.05 | Δρmax = 0.25 e Å−3 |
2718 reflections | Δρmin = −0.17 e Å−3 |
211 parameters |
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'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 > σ(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 | ||
C14 | 0.6599 (2) | −0.1768 (2) | 1.05001 (19) | 0.0485 (4) | |
H14A | 0.5629 | −0.2265 | 1.0509 | 0.073* | |
H14B | 0.7023 | −0.1440 | 1.1450 | 0.073* | |
H14C | 0.7431 | −0.2282 | 1.0210 | 0.073* | |
C15 | 0.6072 (3) | −0.3610 (2) | 0.7190 (3) | 0.0648 (5) | |
H15A | 0.7103 | −0.3776 | 0.6906 | 0.097* | |
H15B | 0.5426 | −0.4367 | 0.7113 | 0.097* | |
H15C | 0.6289 | −0.3319 | 0.8172 | 0.097* | |
C1 | 0.46449 (18) | −0.06799 (17) | 0.82978 (17) | 0.0403 (3) | |
H1 | 0.4716 | −0.0145 | 0.7470 | 0.048* | |
C2 | 0.3450 (2) | −0.1765 (2) | 0.7955 (2) | 0.0521 (4) | |
H2A | 0.2344 | −0.1481 | 0.8005 | 0.063* | |
H2B | 0.3768 | −0.2417 | 0.8675 | 0.063* | |
C3 | 0.3418 (3) | −0.2314 (3) | 0.6452 (3) | 0.0644 (6) | |
H3A | 0.2744 | −0.3068 | 0.6327 | 0.077* | |
H3B | 0.2905 | −0.1712 | 0.5724 | 0.077* | |
C4 | 0.5134 (3) | −0.2628 (2) | 0.6226 (2) | 0.0537 (4) | |
C5 | 0.5937 (2) | −0.1649 (2) | 0.55053 (18) | 0.0501 (4) | |
H5 | 0.5264 | −0.0892 | 0.5253 | 0.060* | |
C6 | 0.7768 (2) | −0.14210 (17) | 0.57840 (17) | 0.0447 (4) | |
H6 | 0.8377 | −0.2171 | 0.6195 | 0.054* | |
C7 | 0.82874 (19) | −0.02749 (15) | 0.67649 (15) | 0.0366 (3) | |
H7 | 0.7357 | 0.0318 | 0.6601 | 0.044* | |
C8 | 0.87578 (18) | −0.05478 (18) | 0.83958 (15) | 0.0393 (3) | |
H8A | 0.8723 | −0.1449 | 0.8535 | 0.047* | |
H8B | 0.9894 | −0.0279 | 0.8751 | 0.047* | |
C9 | 0.76603 (17) | 0.00787 (16) | 0.93218 (15) | 0.0352 (3) | |
H9 | 0.8333 | 0.0204 | 1.0295 | 0.042* | |
C10 | 0.61532 (17) | −0.06993 (15) | 0.94522 (15) | 0.0356 (3) | |
C11 | 0.9645 (2) | 0.02787 (18) | 0.61024 (19) | 0.0464 (4) | |
C12 | 0.9353 (3) | −0.0178 (2) | 0.4586 (2) | 0.0559 (5) | |
C13 | 1.0911 (3) | 0.1006 (3) | 0.6654 (3) | 0.0665 (6) | |
H13A | 1.1656 | 0.1250 | 0.6091 | 0.080* | |
H13B | 1.1060 | 0.1276 | 0.7607 | 0.080* | |
C16 | 0.8244 (2) | 0.22159 (18) | 0.9006 (2) | 0.0460 (4) | |
C17 | 0.7628 (3) | 0.3407 (2) | 0.8271 (2) | 0.0597 (5) | |
H17A | 0.7451 | 0.4011 | 0.8976 | 0.090* | |
H17B | 0.6600 | 0.3254 | 0.7600 | 0.090* | |
H17C | 0.8432 | 0.3726 | 0.7760 | 0.090* | |
O1 | 0.5260 (3) | −0.2753 (2) | 0.47208 (17) | 0.0731 (5) | |
O2 | 0.47027 (14) | −0.00130 (14) | 0.96360 (14) | 0.0473 (3) | |
O3 | 0.8194 (2) | −0.10899 (18) | 0.44012 (14) | 0.0622 (4) | |
O4 | 0.9965 (3) | 0.0176 (3) | 0.36135 (19) | 0.0840 (6) | |
O5 | 0.71087 (14) | 0.12924 (11) | 0.87370 (13) | 0.0387 (2) | |
O6 | 0.96035 (19) | 0.20593 (19) | 0.9760 (2) | 0.0711 (5) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C14 | 0.0535 (9) | 0.0498 (10) | 0.0430 (8) | 0.0018 (8) | 0.0119 (7) | 0.0129 (7) |
C15 | 0.0920 (16) | 0.0371 (9) | 0.0689 (13) | 0.0029 (10) | 0.0251 (12) | 0.0000 (9) |
C1 | 0.0353 (6) | 0.0393 (7) | 0.0477 (7) | 0.0015 (6) | 0.0119 (5) | 0.0030 (6) |
C2 | 0.0378 (7) | 0.0526 (10) | 0.0660 (11) | −0.0065 (7) | 0.0109 (7) | 0.0037 (9) |
C3 | 0.0513 (10) | 0.0673 (14) | 0.0683 (12) | −0.0167 (10) | −0.0022 (9) | −0.0061 (11) |
C4 | 0.0654 (11) | 0.0462 (10) | 0.0474 (9) | −0.0088 (8) | 0.0072 (8) | −0.0093 (7) |
C5 | 0.0593 (9) | 0.0500 (10) | 0.0377 (7) | −0.0004 (8) | 0.0028 (7) | 0.0003 (7) |
C6 | 0.0588 (9) | 0.0410 (8) | 0.0367 (7) | 0.0087 (7) | 0.0156 (6) | 0.0014 (6) |
C7 | 0.0414 (6) | 0.0376 (7) | 0.0331 (6) | 0.0092 (5) | 0.0134 (5) | 0.0039 (5) |
C8 | 0.0379 (6) | 0.0472 (8) | 0.0340 (6) | 0.0098 (6) | 0.0105 (5) | 0.0069 (6) |
C9 | 0.0367 (6) | 0.0383 (7) | 0.0307 (5) | −0.0009 (5) | 0.0077 (4) | −0.0002 (5) |
C10 | 0.0374 (6) | 0.0353 (7) | 0.0366 (6) | 0.0030 (5) | 0.0135 (5) | 0.0008 (5) |
C11 | 0.0546 (8) | 0.0436 (8) | 0.0470 (8) | 0.0113 (7) | 0.0244 (7) | 0.0111 (7) |
C12 | 0.0688 (11) | 0.0586 (12) | 0.0482 (9) | 0.0182 (10) | 0.0303 (8) | 0.0098 (8) |
C13 | 0.0757 (14) | 0.0592 (13) | 0.0730 (13) | −0.0089 (11) | 0.0347 (11) | 0.0052 (11) |
C16 | 0.0531 (9) | 0.0411 (8) | 0.0491 (8) | −0.0111 (7) | 0.0231 (7) | −0.0132 (7) |
C17 | 0.0799 (13) | 0.0397 (9) | 0.0674 (12) | −0.0121 (10) | 0.0336 (10) | −0.0033 (9) |
O1 | 0.0935 (12) | 0.0769 (12) | 0.0452 (8) | −0.0166 (11) | 0.0059 (7) | −0.0190 (8) |
O2 | 0.0473 (6) | 0.0429 (6) | 0.0586 (7) | 0.0051 (5) | 0.0267 (5) | −0.0034 (6) |
O3 | 0.0873 (10) | 0.0679 (10) | 0.0372 (6) | 0.0057 (9) | 0.0268 (6) | −0.0042 (6) |
O4 | 0.1043 (14) | 0.1021 (15) | 0.0613 (9) | 0.0130 (13) | 0.0531 (10) | 0.0150 (11) |
O5 | 0.0410 (5) | 0.0329 (5) | 0.0432 (5) | −0.0035 (4) | 0.0110 (4) | −0.0027 (4) |
O6 | 0.0544 (8) | 0.0626 (10) | 0.0909 (13) | −0.0184 (8) | 0.0025 (8) | −0.0182 (9) |
C14—C10 | 1.504 (2) | C6—C7 | 1.539 (2) |
C14—H14A | 0.9600 | C6—H6 | 0.9800 |
C14—H14B | 0.9600 | C7—C11 | 1.511 (2) |
C14—H14C | 0.9600 | C7—C8 | 1.5386 (19) |
C15—C4 | 1.493 (3) | C7—H7 | 0.9800 |
C15—H15A | 0.9600 | C8—C9 | 1.537 (2) |
C15—H15B | 0.9600 | C8—H8A | 0.9700 |
C15—H15C | 0.9600 | C8—H8B | 0.9700 |
C1—O2 | 1.444 (2) | C9—O5 | 1.442 (2) |
C1—C10 | 1.474 (2) | C9—C10 | 1.519 (2) |
C1—C2 | 1.508 (3) | C9—H9 | 0.9800 |
C1—H1 | 0.9800 | C10—O2 | 1.4419 (18) |
C2—C3 | 1.534 (3) | C11—C13 | 1.316 (3) |
C2—H2A | 0.9700 | C11—C12 | 1.486 (3) |
C2—H2B | 0.9700 | C12—O4 | 1.199 (2) |
C3—C4 | 1.511 (3) | C12—O3 | 1.348 (3) |
C3—H3A | 0.9700 | C13—H13A | 0.9300 |
C3—H3B | 0.9700 | C13—H13B | 0.9300 |
C4—O1 | 1.456 (3) | C16—O6 | 1.207 (3) |
C4—C5 | 1.476 (3) | C16—O5 | 1.345 (2) |
C5—O1 | 1.439 (3) | C16—C17 | 1.484 (3) |
C5—C6 | 1.496 (3) | C17—H17A | 0.9600 |
C5—H5 | 0.9800 | C17—H17B | 0.9600 |
C6—O3 | 1.467 (2) | C17—H17C | 0.9600 |
C10—C14—H14A | 109.5 | C7—C6—H6 | 110.6 |
C10—C14—H14B | 109.5 | C11—C7—C8 | 115.88 (14) |
H14A—C14—H14B | 109.5 | C11—C7—C6 | 101.30 (13) |
C10—C14—H14C | 109.5 | C8—C7—C6 | 115.81 (14) |
H14A—C14—H14C | 109.5 | C11—C7—H7 | 107.8 |
H14B—C14—H14C | 109.5 | C8—C7—H7 | 107.8 |
C4—C15—H15A | 109.5 | C6—C7—H7 | 107.8 |
C4—C15—H15B | 109.5 | C9—C8—C7 | 115.78 (12) |
H15A—C15—H15B | 109.5 | C9—C8—H8A | 108.3 |
C4—C15—H15C | 109.5 | C7—C8—H8A | 108.3 |
H15A—C15—H15C | 109.5 | C9—C8—H8B | 108.3 |
H15B—C15—H15C | 109.5 | C7—C8—H8B | 108.3 |
O2—C1—C10 | 59.23 (10) | H8A—C8—H8B | 107.4 |
O2—C1—C2 | 117.75 (14) | O5—C9—C10 | 108.82 (11) |
C10—C1—C2 | 124.07 (16) | O5—C9—C8 | 110.26 (12) |
O2—C1—H1 | 114.7 | C10—C9—C8 | 113.44 (13) |
C10—C1—H1 | 114.7 | O5—C9—H9 | 108.1 |
C2—C1—H1 | 114.7 | C10—C9—H9 | 108.1 |
C1—C2—C3 | 112.05 (17) | C8—C9—H9 | 108.1 |
C1—C2—H2A | 109.2 | O2—C10—C1 | 59.36 (10) |
C3—C2—H2A | 109.2 | O2—C10—C14 | 113.50 (13) |
C1—C2—H2B | 109.2 | C1—C10—C14 | 123.48 (15) |
C3—C2—H2B | 109.2 | O2—C10—C9 | 116.46 (13) |
H2A—C2—H2B | 107.9 | C1—C10—C9 | 120.62 (13) |
C4—C3—C2 | 112.34 (16) | C14—C10—C9 | 112.01 (13) |
C4—C3—H3A | 109.1 | C13—C11—C12 | 122.04 (18) |
C2—C3—H3A | 109.1 | C13—C11—C7 | 131.20 (19) |
C4—C3—H3B | 109.1 | C12—C11—C7 | 106.75 (17) |
C2—C3—H3B | 109.1 | O4—C12—O3 | 121.8 (2) |
H3A—C3—H3B | 107.9 | O4—C12—C11 | 129.0 (3) |
O1—C4—C5 | 58.81 (14) | O3—C12—C11 | 109.18 (15) |
O1—C4—C15 | 113.58 (19) | C11—C13—H13A | 120.0 |
C5—C4—C15 | 123.53 (19) | C11—C13—H13B | 120.0 |
O1—C4—C3 | 114.76 (18) | H13A—C13—H13B | 120.0 |
C5—C4—C3 | 115.6 (2) | O6—C16—O5 | 122.27 (19) |
C15—C4—C3 | 116.7 (2) | O6—C16—C17 | 125.43 (18) |
O1—C5—C4 | 59.90 (14) | O5—C16—C17 | 112.30 (16) |
O1—C5—C6 | 119.44 (19) | C16—C17—H17A | 109.5 |
C4—C5—C6 | 124.49 (17) | C16—C17—H17B | 109.5 |
O1—C5—H5 | 114.1 | H17A—C17—H17B | 109.5 |
C4—C5—H5 | 114.1 | C16—C17—H17C | 109.5 |
C6—C5—H5 | 114.1 | H17A—C17—H17C | 109.5 |
O3—C6—C5 | 107.57 (14) | H17B—C17—H17C | 109.5 |
O3—C6—C7 | 105.02 (14) | C5—O1—C4 | 61.28 (13) |
C5—C6—C7 | 112.25 (14) | C10—O2—C1 | 61.41 (10) |
O3—C6—H6 | 110.6 | C12—O3—C6 | 110.63 (14) |
C5—C6—H6 | 110.6 | C16—O5—C9 | 115.58 (13) |
Experimental details
Crystal data | |
Chemical formula | C17H22O6 |
Mr | 322.35 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 298 |
a, b, c (Å) | 8.2390 (3), 10.6482 (4), 9.4633 (3) |
β (°) | 102.039 (2) |
V (Å3) | 811.96 (5) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.10 |
Crystal size (mm) | 0.38 × 0.27 × 0.12 |
Data collection | |
Diffractometer | Bruker X8 APEX CCD area-detector |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 12911, 2718, 2480 |
Rint | 0.023 |
(sin θ/λ)max (Å−1) | 0.726 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.038, 0.115, 1.05 |
No. of reflections | 2718 |
No. of parameters | 211 |
No. of restraints | 1 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.25, −0.17 |
Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).
Acknowledgements
The authors thank the Unit of Support for Technical and Scientific Research (UATRS, CNRST) for the X-ray measurements.
References
Abdel Sattar, E., Galal, A. M. & Mossa, J. S. (1996). J. Nat. Prod. 59, 403–405. CrossRef CAS PubMed Google Scholar
Bruker (2007). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Castaneda-Acosta, J., Fisher, N. H. & Varga, D. (1993). J. Nat. Prod. 56, 90–98. CrossRef CAS PubMed Web of Science Google Scholar
Castaneda-Acosta, J., Pentes, H. G., Fronczek, F. R. & Fischer, N. H. (1997). J. Chem. Crystallogr. 27, 635–639. Web of Science CrossRef CAS Google Scholar
Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354–1358. CrossRef CAS Web of Science Google Scholar
El Hassany, B., El Hanbali, F., Akssira, M., Mellouki, F., Haidou, A. & Barero, A. F. (2004). Fitoterapia, 75, 573–576. Web of Science CrossRef PubMed CAS Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Moumou, M., Akssira, M., El Ammari, L., Benharref, A. & Berraho, M. (2010). Acta Cryst. E66, o2395. Web of Science CSD CrossRef IUCr Journals Google Scholar
Neukirch, H., Kaneider, N. C., Wiedermann, C. J., Guerriero, A. & D'Ambrosio, M. (2003). Bioorg. Med. Chem. 11, 1503–1510. Web of Science CrossRef PubMed CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Watson, W. H. & Zabel, V. (1982). Acta Cryst. B38, 834–838. CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
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The Natural sesquiterpene lactone (9α-hydroxyparthenolide) is the main constituent of the chloroform extract of aerial parts of Anvillea radiata (El Hassany et al., 2004), and of Anvillea garcini(Abdel Sattar et al.,1996). The reactivity of this sesuiterpène and its derivatives has been the subject of several studies (Castaneda-Acosta et al.,1993; Neukirch et al., 2003), in order to prepare products with high value added, used in industrial pharmacology. In the same context, we carried out the acetylation followed by epoxydation of 9α-hydroxyparthenolide. Thus, the action of one equivalent of acetic anhydride on this sesquiterpene in pyridine at 0°C leads to quantitative yield 9α-acétoxyparthenolide. The treatment of this latter with one equivalent of meta-choroperbenzoïque acid (mCPBA) in dichloromethane at room temperature gives 9α-acetoxy-1β, 10β-epoxyparthenolide with a yield of 95%. The structure of this new product was determined by NMR spectral analysis of 1H, 13 C and mass spectrometry, and confirmed by a study of X ray crystallography. The structure of (I) was established by 1H and 13 C NMR and confirmed by its single-crystal X-ray structure.The molecule is built up from two fused five-and ten-membered rings.(Fig. 1). The five-membered ring adopts a twisted conformation,as indicated by Cremer & Pople (1975) puckering parameters Q = 0.26 (2) Å and φ = 23.77 (4)°. The ten-membered ring displays an approximate chair-chair conformation. This is the typical conformation observed for other sesquiterpenes lactones (Moumou et al., 2010; Watson & Zabel, 1982; Castaneda-Acosta et al., 1997).