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Volume 64 
Part 2 
Page o529  
February 2008  

Received 20 December 2007
Accepted 24 January 2008
Online 30 January 2008

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Key indicators
Single-crystal X-ray study
T = 295 K
Mean [sigma](C-C) = 0.004 Å
R = 0.058
wR = 0.149
Data-to-parameter ratio = 10.0
Details
Open access

Aromaticine, a sesquiterpene lactone from Amblyopappus pusillus

Iván Brito,a* Jorge Bórquez,a Luis Alberto Loyolaa and Matías López-Rodríguezb

aDepartamento de Química, Facultad de Ciencias Básicas, Universidad de Antofagasta, Casilla 170, Antofagasta, Chile, and bInstituto de Bio-Orgánica 'Antonio González', Universidad de La Laguna, Astrofísico Francisco Sánchez No. 2, La Laguna, Tenerife, Spain
Correspondence e-mail: ivanbritob@yahoo.com

Aromaticine (systematic name: 4a,8-dimethyl-3-methylene-3,3a,4,4a,7a,8,9,9a-octahydroazuleno[6,5-b]furan-2,5-dione), C15H18O3, is a natural lactone isolated from Amblyopappus pusillus. The molecular structure and conformation agree with the results of Romo, Joseph-Nathan & Díaz [(1964[Romo, J., Joseph-Nathan, J. & Díaz, F. (1964). Tetrahedron, 20, 79-85.]). Tetrahedron, 20, 79-85]. The fused-ring system contains a seven-membered ring in a twist-boat conformation and two five-membered rings trans fused in envelope conformations.

Related literature

For related literature, see: Allen et al. (1987[Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1-19.]); Bórquez (2006[Bórquez, J. (2006). Unpublished results.]); Bernstein et al. (1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.]); Cremer & Pople (1975[Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354-1358.]); Rodríguez et al. (1976[Rodríguez, E., Towers, G. H. N. & Mitchell, J. C. (1976). Phytochemistry, 15, 1573-1580.]); Romo et al. (1964[Romo, J., Joseph-Nathan, J. & Díaz, F. (1964). Tetrahedron, 20, 79-85.]).

[Scheme 1]

Experimental

Crystal data

  • C15H18O3

  • Mr = 246.29

  • Orthorhombic, P 21 21 21

  • a = 6.763 (4) Å

  • b = 9.932 (5) Å

  • c = 18.685 (7) Å

  • V = 1255.1 (11) Å3

  • Z = 4

  • Mo K[alpha] radiation

  • [mu] = 0.09 mm-1

  • T = 295 (2) K

  • 0.40 × 0.10 × 0.08 mm
Data collection

  • Nonius KappaCCD area-detector diffractometer

  • Absorption correction: none

  • 16315 measured reflections

  • 1667 independent reflections

  • 1432 reflections with I > 2[sigma](I)

  • Rint = 0.051
Refinement

  • R[F2 > 2[sigma](F2)] = 0.057

  • wR(F2) = 0.148

  • S = 1.20

  • 1667 reflections

  • 167 parameters

  • H-atom parameters constrained

  • [Delta][rho]max = 0.24 e Å-3

  • [Delta][rho]min = -0.23 e Å-3

Data collection: COLLECT (Nonius, 1998[Nonius (1998). COLLECT. Nonius BV, Delft, The Netherlands.]); cell refinement: DENZO-SMN (Otwinowski & Minor, 1997[Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307-326. New York: Academic Press.]); data reduction: DENZO-SMN; program(s) used to solve structure: SIR97 (Altomare et al., 1999[Altomare, A., Burla, M. C., Camalli, M., Cascarano, G. L., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1999). J. Appl. Cryst. 32, 115-119.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]) and PLATON (Spek, 2003[Spek, A. L. (2003). J. Appl. Cryst. 36, 7-13.]); software used to prepare material for publication: WinGX (Farrugia, 1999[Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.]).

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: OM2203 ).

Acknowledgements

We thank the Spanish Research Council (CSIC) for providing us with a free-of-charge licence for the CSD system.

References

Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1-19.
Altomare, A., Burla, M. C., Camalli, M., Cascarano, G. L., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1999). J. Appl. Cryst. 32, 115-119.  [CrossRef] [details]
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.  [CrossRef] [ChemPort] [ISI]
Bórquez, J. (2006). Unpublished results.
Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354-1358.  [CrossRef] [ChemPort] [ISI]
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.  [CrossRef] [details]
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.  [CrossRef] [details]
Nonius (1998). COLLECT. Nonius BV, Delft, The Netherlands.
Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307-326. New York: Academic Press.
Rodríguez, E., Towers, G. H. N. & Mitchell, J. C. (1976). Phytochemistry, 15, 1573-1580.  [CrossRef] [ChemPort] [ISI]
Romo, J., Joseph-Nathan, J. & Díaz, F. (1964). Tetrahedron, 20, 79-85.  [CrossRef] [ChemPort]
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.  [CrossRef] [details]
Spek, A. L. (2003). J. Appl. Cryst. 36, 7-13.  [CrossRef] [details]

Acta Cryst (2008). E64, o529  [ doi:10.1107/S1600536808002729 ]

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