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Volume 68 
Part 11 
Page o3251  
November 2012  

Received 1 August 2012
Accepted 25 October 2012
Online 31 October 2012

Key indicators
Single-crystal X-ray study
T = 133 K
Mean [sigma](C-C) = 0.003 Å
R = 0.047
wR = 0.124
Data-to-parameter ratio = 10.8
Details
Open access

6,8-Dihydroxy-8a-methyl-3,5-dimethylidenedecahydronaphtho[2,3-b]furan-2(3H)-one

aCollege of Life and Environment Science, Minzu University of China, Beijing 100081, People's Republic of China
Correspondence e-mail: wangws@muc.edu.cn

The title compound, C15H20O4, is a eudesmanolide isolated from the Chinese medicinal plant Carpesium triste Maxim. The molecule contains three rings, viz. two fused six-membered rings in chair conformations and a five-membered ring in a flattened envelope conformation. In the crystal, two hydroxy groups are involved in the formation of intra- and intermolecular O-H...O hydrogen bonds. The H atoms in these groups are split, with site-occupation factors of 0.5. The intermolecular hydrogen bonds link molecules into chains propagating in [010].

Related literature

For related compounds extracted from Carpesium triste Maxim, see: Masao & Fumiko (1975[Masao, M. & Fumiko, S. (1975). Phytochemistry, 14, 2247-2248.]).

[Scheme 1]

Experimental

Crystal data
  • C15H20O4

  • Mr = 264.31

  • Tetragonal, P 41 21 2

  • a = 6.4737 (4) Å

  • c = 62.438 (8) Å

  • V = 2616.7 (5) Å3

  • Z = 8

  • Mo K[alpha] radiation

  • [mu] = 0.10 mm-1

  • T = 133 K

  • 0.54 × 0.48 × 0.32 mm

Data collection
  • Rigaku AFC10/Saturn-724+ CCD diffractometer

  • 19607 measured reflections

  • 1990 independent reflections

  • 1826 reflections with I > 2[sigma](I)

  • Rint = 0.058

Refinement
  • R[F2 > 2[sigma](F2)] = 0.047

  • wR(F2) = 0.124

  • S = 1.00

  • 1990 reflections

  • 185 parameters

  • 6 restraints

  • H atoms treated by a mixture of independent and constrained refinement

  • [Delta][rho]max = 0.23 e Å-3

  • [Delta][rho]min = -0.21 e Å-3

Table 1
Hydrogen-bond geometry (Å, °)

D-H...A D-H H...A D...A D-H...A
O2-H2O...O2i 0.84 (1) 1.90 (1) 2.733 (3) 173 (5)
O2-H2O'...O3 0.84 (1) 1.94 (2) 2.690 (2) 148 (2)
O3-H3O'...O2 0.84 (1) 1.97 (4) 2.690 (2) 143 (5)
O3-H3O...O3ii 0.83 (1) 1.88 (2) 2.697 (3) 168 (6)
Symmetry codes: (i) y, x, -z; (ii) y+1, x-1, -z.

Data collection: CrystalClear (Rigaku/MSC, 2008[Rigaku/MSC (2008). CrystalClear. Rigaku/MSC Inc., The Woodlands, Texas, USA.]); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.


Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: RK2376 ).


Acknowledgements

The project was supported by the 985 Project (grant Nos. MUC98504-14, MUC98507-08), Minzu University of China, together with the `Programme of Introducing Talents of Discipline to Universities' (grant No. B08044), and the `Project for Scientific and Technical Achievements in Industrialization', Beijing Education Commission.

References

Masao, M. & Fumiko, S. (1975). Phytochemistry, 14, 2247-2248.
Rigaku/MSC (2008). CrystalClear. Rigaku/MSC Inc., The Woodlands, Texas, USA.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.  [CrossRef] [details]


Acta Cryst (2012). E68, o3251  [ doi:10.1107/S160053681204425X ]

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