2,6-Dimethyl-4-m-tolyl­cyclo­hex-3-enecarboxylic acid

Xie, S.; Stein, H.J.; Pink, M.

doi:10.1107/S1600536808027542

Volume 64
Part 10
Page o1869
October 2008

Received 29 July 2008
Accepted 27 August 2008
Online 6 September 2008

Key indicators
Single-crystal X-ray study
T = 150 K
Mean (C-C) = 0.002 Å
R = 0.049
wR = 0.137
Data-to-parameter ratio = 18.4
Details

2,6-Dimethyl-4-m-tolylcyclohex-3-enecarboxylic acid

Songwen Xie,^a ^* Holly J. Stein ^a and Maren Pink ^b

^aDepartment of Natural Information and Mathematical Sciences, Indiana University Kokomo, Kokomo, IN 46904-9003, USA, and ^bIndiana University Molecular Structure Center, Indiana University, Bloomington, IN 47405-7102, USA
Correspondence e-mail: soxie@iuk.edu

The title compound, C₁₆H₂₀O₂, was synthesized to study the hydrogen-bonding interaction of the two enantiomers in the solid state. The racemate is made up of carboxylic acid RS dimers. Intermolecular O-HO hydrogen bonds produce centrosymmetric R₂²(8) rings which dimerize the two chiral enantiomers through their carboxyl groups. The chirality of this compound is generated by the presence of the double bond in the cyclohexene ring and a chiral axis due to the meta-methyl substituent on the aromatic ring.

Related literature

In similar compounds previously reported (Xie et al., 2002, 2007a, 2008), the racemates also consist of carboxylic acid RS dimers. For related literature, see: Xie et al. (2007b, 2004); Bernstein et al. (1995).

Experimental

Crystal data

C₁₆H₂₀O₂
M_r = 244.32
Orthorhombic, P b c a
a = 11.2581 (10) Å
b = 8.1055 (7) Å
c = 29.857 (3) Å
V = 2724.5 (4) Å³
Z = 8
Mo K radiation
= 0.08 mm^-1
T = 150 (2) K
0.20 × 0.18 × 0.05 mm

Data collection

Bruker Kappa APEXII diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) T_min = 0.985, T_max = 0.996
18515 measured reflections
3120 independent reflections
2265 reflections with I > 2(I)
R_int = 0.043

Refinement

R[F² > 2(F²)] = 0.049
wR(F²) = 0.136
S = 1.03
3120 reflections
170 parameters
H atoms treated by a mixture of independent and constrained refinement
_max = 0.50 e Å^-3
_min = -0.20 e Å^-3

Table 1
Hydrogen-bond geometry (Å, °)

D-HA	D-H	HA	DA	D-HA
O1-H1OO2ⁱ	1.05 (3)	1.62 (3)	2.6628 (18)	174 (3)
Symmetry code: (i) -x+1, -y, -z+1.

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SIR2004 (Burla et al., 2005); 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: OM2254 ).

Acknowledgements

SX and HS are grateful to the departmental fund and the Grant-in-aid for Faculty Research from Indiana University Kokomo, as well as a Senior Research Grant from Indiana Academy of Science.

References

Bernstein, J., Davis, R., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.
Bruker (2007). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.
Burla, M. C., Caliandro, R., Camalli, M., Carrozzini, B., Cascarano, G. L., De Caro, L., Giacovazzo, C., Polidori, G. & Spagna, R. (2005). J. Appl. Cryst. 38, 381-388.
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.
Xie, S., Hou, Y., Meyers, C. Y. & Robinson, P. D. (2002). Acta Cryst. E58, o1460-o1462.
Xie, S., Kenny, C. & Robinson, P. D. (2007a). Acta Cryst. E63, o3897.
Xie, S., Kenny, C. & Robinson, P. D. (2007b). Acta Cryst. E63, o1660-o1662.
Xie, S., Meyers, C. Y. & Robinson, P. D. (2004). Acta Cryst. E60, o1362-o1364.
Xie, S., O'Hearn, C. R. & Robinson, P. D. (2008). Acta Cryst. E64, o554.

organic compounds