(IUCr) 1,4a,7-Trimethyl-7-vinyl-1,2,3,4,4a,4b,5,6,7,8,10,10a-dodecahydrophenanthrene-1-carboxylic acid

Volume 65
Part 6
Page o1429
June 2009

Received 19 May 2009
Accepted 21 May 2009
Online 29 May 2009

Key indicators
Single-crystal X-ray study
T = 293 K
Mean (C-C) = 0.010 Å
R = 0.069
wR = 0.150
Data-to-parameter ratio = 9.3
Details

1,4a,7-Trimethyl-7-vinyl-1,2,3,4,4a,4b,5,6,7,8,10,10a-dodecahydrophenanthrene-1-carboxylic acid

Zhen-Dong Zhao,^a ^* Yu-Xiang Chen,^a Yu-Min Wang ^a and Liang-Wu Bi ^a

^aInstitute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Nanjing 210042, People's Republic of China
Correspondence e-mail: sbkf@tom.com

The title compound, also known as isopimaric acid, C₂₀H₃₀O₂, was isolated from slash pine rosin. There are two unique molecules in the unit cell. The two cyclohexane rings have classical chair conformations. The cyclohexene ring represents a semi-chair. The molecular conformation is stabilized by weak intramolecular C-HO hydrogen-bonding interactions. The molecules are dimerized through their carboxyl groups by O-HO hydrogen bonds, forming R₂²(8) rings.

Related literature

For physical and spectroscopic analysis, see: Baldwin et al. (1958); Harris & Sanderson (1948). For biological activities, see: Smith et al. (2005); Russo et al. (2007).

Experimental

Crystal data

C₂₀H₃₀O₂
M_r = 302.44
Orthorhombic, P 2₁ 2₁ 2₁
a = 11.624 (2) Å
b = 11.803 (2) Å
c = 25.698 (5) Å
V = 3525.7 (12) Å³
Z = 8
Mo K radiation
= 0.07 mm^-1
T = 293 K
0.20 × 0.10 × 0.10 mm

Data collection

Enraf-Nonius CAD-4 diffractometer
Absorption correction: scan (North et al., 1968) T_min = 0.986, T_max = 0.993
7031 measured reflections
6382 independent reflections
2613 reflections with I > 2(I)
R_int = 0.088
3 standard reflections every 200 reflections intensity decay: 1%

Refinement

R[F² > 2(F²)] = 0.069
wR(F²) = 0.150
S = 1.00
3598 reflections
385 parameters
1 restraint
H-atom parameters constrained
_max = 0.24 e Å^-3
_min = -0.26 e Å^-3

Table 1
Hydrogen-bond geometry (Å, °)

D-HA	D-H	HA	DA	D-HA
O2-H2BO4ⁱ	0.82	1.84	2.653 (7)	168
O3-H3DO1ⁱⁱ	0.82	1.85	2.655 (7)	168
C11-H11AO1	0.98	2.34	2.764 (7)	105
C32-H32BO4	0.97	2.49	3.081 (9)	119
Symmetry codes: (i) $[x+{\script{1\over 2}}, -y+{\script{5\over 2}}, -z+2]$ ; (ii) $[x-{\script{1\over 2}}, -y+{\script{5\over 2}}, -z+2]$ .

Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: AT2789 ).

Acknowledgements

This work was supported by the Natural Science Fund of Jiangsu Province under grant No. BK2006011 and the National Natural Science Foundation of China under grant No. 30571466.

References

Baldwin, D. E., Loeblich, V. M. & Lawrence, R. V. (1958). J. Org. Chem. 23, 25-26.
Enraf-Nonius (1989). CAD-4 Software. Enraf-Nonius, Delft, The Netherlands.
Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany.
Harris, G. C. & Sanderson, T. F. (1948). J. Am. Chem. Soc. 70, 2079-2081.
North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351-359.
Russo, R., Loverme, J., Rana, G. L., D'Agostino, G., Sasso, O., Calignano, A. & Piomelli, D. (2007). Eur. J. Pharmacol. 566, 117-119.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.
Smith, E., Williamson, E., Zloh, M. & Gibbons, S. (2005). Phytother. Res. 19, 538-542.

organic compounds