organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

2,6,6-Tri­methyl­cyclo­hex-2-ene­carb­­oxy­lic acid

aDepartment of Chemistry, National Institute of Technology, Tiruchirappalli 620 015, India, bSchool of Chemistry, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu, India, and cDepartment of Chemistry, National Institute of Technology, Karaikal 609 605, India
*Correspondence e-mail: tommtrichy@yahoo.co.in

(Received 15 January 2012; accepted 21 January 2012; online 31 January 2012)

In the title crystal structure, C10H16O2, inversion-related mol­ecules are linked by pairs of O—H⋯O hydrogen bonds involving carboxyl groups to form R22(8) dimers. The cyclo­hexene ring displays a half-chair conformation.

Related literature

For information on the title compound as used as a key inter­mediate in chemical synthesis, see: Eugster et al. (1969[Eugster, C. H., Buchecker, R., Tscharner, C., Uhde, G. & Ohloff, G. (1969). Helv. Chim. Acta, 52, 1729-1731.]); Naef & Decorzant (1986[Naef, F. & Decorzant, R. (1986). Tetrahedron, 42, 3245-3250.]); Snowden et al. (1982[Snowden, R. L., Muller, B. L. & Schulte-Elte, K. H. (1982). Tetrahedron Lett. 23, 335-338.]); Fehr & Galindo (1986[Fehr, C. & Galindo, J. (1986). Helv. Chim. Acta, 69, 228-235.], 1995[Fehr, C. & Galindo, J. (1995). Helv. Chim. Acta, 78, 539-552.]); Heather et al. (1976[Heather, J. B., Mittal, R. S. D. & Sih, C. J. (1976). J. Am. Chem. Soc. 98, 3661-3669.]). For hydrogen-bond graph-set notation, see: Etter et al. (1990[Etter, M. C., MacDonald, J. C. & Bernstein, J. (1990). Acta Cryst. B46, 256-262.]); Bernstein et al. (1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.]).

[Scheme 1]

Experimental

Crystal data
  • C10H16O2

  • Mr = 168.23

  • Monoclinic, P 21 /c

  • a = 7.6817 (1) Å

  • b = 10.4137 (2) Å

  • c = 13.4421 (2) Å

  • β = 112.924 (1)°

  • V = 990.38 (3) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.08 mm−1

  • T = 296 K

  • 0.09 × 0.08 × 0.05 mm

Data collection
  • Bruker SMART APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2008[Bruker (2008). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.993, Tmax = 0.996

  • 10045 measured reflections

  • 2158 independent reflections

  • 1560 reflections with I > 2σ(I)

  • Rint = 0.026

Refinement
  • R[F2 > 2σ(F2)] = 0.049

  • wR(F2) = 0.134

  • S = 1.03

  • 2158 reflections

  • 120 parameters

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

  • Δρmax = 0.25 e Å−3

  • Δρmin = −0.17 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O2—H2A⋯O1i 1.01 (4) 1.64 (4) 2.646 (2) 178 (4)
Symmetry code: (i) -x+1, -y+1, -z+1.

Data collection: APEX2 (Bruker, 2008[Bruker (2008). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2008[Bruker (2008). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; 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: PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]); software used to prepare material for publication: PLATON.

Supporting information


Comment top

The title compound is a key intermediate for the synthesis of aroma compounds such as alpha, beta methyl cyclo geranate (Eugster et al., 1969), alpha damascone (Naef & Decorzant, 1986; Snowden et al., 1982), beta damascone (Fehr & Galindo, 1986), gamma damascone (Fehr & Galindo, 1995) and strigol which is a highly potent stimulant for the germination of seeds of parasitic weeds striga and orobanche (Heather et al., 1976). Moreover, the 2,6,6-tri methylcyclohexenyl moiety is a basic moiety for natural product of carotenoid, which is a naturally occurring organic pigment in the chloroplasts and chromoplasts of plants. Herein, we report the crystal and molecular structure of the title compound (Fig. 1). In the crystal, inversion-related molecules are connected via a pair of O—H···O hydrogen bonds, (Table 1) forming a cyclic dimer [graph-set R22(8) (Etter et al., 1990; Bernstein et al., 1995)] (Fig. 2). This type of cyclic donor···acceptor···acceptor···donor interaction involving O—H···O hydrogen bonds is frequently observed in carboxylic acids

Related literature top

For information on the title compound as used as a key intermediate in chemical synthesis, see: Eugster et al. (1969); Naef & Decorzant (1986); Snowden et al. (1982); Fehr & Galindo (1986, 1995); Heather et al. (1976). For hydrogen-bond graph-set notation, see: Etter et al. (1990); Bernstein et al. (1995).

Experimental top

A solution of 8 g (0.07 mol) of 80% sodium chlorite in 70 ml H2O was added drop wise for 2 h at room temperature to a stirred mixture of 6.6 g (0.05 mol) of cyclo citral in 50 ml Me2SO and of 1.6 g NaH2PO4 in 20 ml of water. The mixture was left overnight at room temperature, then 100 ml of water was added to the reaction mixture. The solid geranic acid was collected and crystallized from hexane.

Refinement top

The H atom attached to O2 was located in a difference Fourier map and refined freely. The remaining H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms, with C—H distances in the range 0.93–0.97 Å, and with Uiso(H) set at 1.2Ueq(C), except for the methyl hydrogen atoms which were refined with Uiso(H) set at 1.5Ueq(C).

Computing details top

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, with anisotropic displacement ellipsoids drawn at 50% probability level.
[Figure 2] Fig. 2. A centrosymmetric R22(8) hydrogen-bonded dimer unit, with hydrogen bonds shown as dashed lines. For symmetry code (i), see Table 1.
2,6,6-Trimethylcyclohex-2-enecarboxylic acid top
Crystal data top
C10H16O2F(000) = 368
Mr = 168.23Dx = 1.128 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 3232 reflections
a = 7.6817 (1) Åθ = 2.9–25.1°
b = 10.4137 (2) ŵ = 0.08 mm1
c = 13.4421 (2) ÅT = 296 K
β = 112.924 (1)°Prism, colourless
V = 990.38 (3) Å30.09 × 0.08 × 0.05 mm
Z = 4
Data collection top
Bruker SMART APEXII CCD
diffractometer
2158 independent reflections
Radiation source: fine-focus sealed tube1560 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.026
ϕ and ω scansθmax = 27.0°, θmin = 2.6°
Absorption correction: multi-scan
(SADABS; Bruker, 2008)
h = 98
Tmin = 0.993, Tmax = 0.996k = 138
10045 measured reflectionsl = 1717
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.049Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.134H atoms treated by a mixture of independent and constrained refinement
S = 1.03 w = 1/[σ2(Fo2) + (0.0541P)2 + 0.2979P]
where P = (Fo2 + 2Fc2)/3
2158 reflections(Δ/σ)max = 0.003
120 parametersΔρmax = 0.25 e Å3
0 restraintsΔρmin = 0.17 e Å3
Crystal data top
C10H16O2V = 990.38 (3) Å3
Mr = 168.23Z = 4
Monoclinic, P21/cMo Kα radiation
a = 7.6817 (1) ŵ = 0.08 mm1
b = 10.4137 (2) ÅT = 296 K
c = 13.4421 (2) Å0.09 × 0.08 × 0.05 mm
β = 112.924 (1)°
Data collection top
Bruker SMART APEXII CCD
diffractometer
2158 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2008)
1560 reflections with I > 2σ(I)
Tmin = 0.993, Tmax = 0.996Rint = 0.026
10045 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0490 restraints
wR(F2) = 0.134H atoms treated by a mixture of independent and constrained refinement
S = 1.03Δρmax = 0.25 e Å3
2158 reflectionsΔρmin = 0.17 e Å3
120 parameters
Special details top

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

Refinement. Refinement on F2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The observed criterion of F2 > σ(F2) is used only for calculating -R-factor-obs 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.5749 (2)0.54166 (13)0.40375 (11)0.0729 (6)
O20.4766 (2)0.35104 (14)0.43135 (12)0.0793 (6)
C10.5737 (2)0.36939 (16)0.28421 (12)0.0432 (5)
C20.4543 (2)0.44209 (16)0.18282 (12)0.0464 (5)
C30.5312 (3)0.52452 (17)0.13678 (13)0.0531 (6)
C40.7364 (3)0.5534 (2)0.17489 (16)0.0612 (7)
C50.8506 (2)0.49910 (18)0.28571 (15)0.0548 (6)
C60.7857 (2)0.36479 (17)0.30219 (13)0.0495 (5)
C70.2461 (3)0.4137 (2)0.13917 (17)0.0723 (8)
C80.9058 (3)0.3161 (2)0.41584 (17)0.0770 (8)
C90.8045 (3)0.2706 (2)0.21865 (18)0.0676 (7)
C100.5421 (2)0.42734 (16)0.37950 (12)0.0467 (5)
H10.527 (2)0.2818 (16)0.2775 (12)0.042 (4)*
H2A0.459 (5)0.394 (4)0.494 (3)0.167 (13)*
H30.450300.567800.075700.0640*
H4A0.753500.645800.176800.0730*
H4B0.784300.518500.123600.0730*
H5A0.840300.556300.340100.0660*
H5B0.982600.495500.295800.0660*
H7A0.197000.433900.193000.1080*
H7B0.225800.324300.120800.1080*
H7C0.182600.464700.075800.1080*
H8A0.858800.234300.427100.1160*
H8B0.899200.376300.468300.1160*
H8C1.034800.307200.423400.1160*
H9A0.720100.295900.147500.1010*
H9B0.772900.185500.233500.1010*
H9C0.932200.271600.222900.1010*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.1202 (12)0.0524 (8)0.0696 (9)0.0172 (8)0.0626 (9)0.0177 (6)
O20.1320 (14)0.0630 (9)0.0742 (9)0.0294 (8)0.0741 (10)0.0186 (7)
C10.0504 (9)0.0410 (9)0.0432 (8)0.0068 (7)0.0238 (7)0.0081 (6)
C20.0455 (9)0.0551 (10)0.0408 (8)0.0020 (7)0.0193 (7)0.0111 (7)
C30.0575 (10)0.0604 (11)0.0418 (8)0.0047 (8)0.0199 (8)0.0005 (7)
C40.0651 (12)0.0624 (12)0.0653 (11)0.0064 (9)0.0354 (10)0.0043 (9)
C50.0451 (9)0.0597 (11)0.0611 (10)0.0083 (8)0.0222 (8)0.0074 (8)
C60.0454 (9)0.0515 (10)0.0516 (9)0.0014 (7)0.0190 (7)0.0027 (7)
C70.0501 (11)0.0970 (16)0.0650 (12)0.0081 (10)0.0172 (9)0.0101 (11)
C80.0661 (13)0.0828 (15)0.0682 (12)0.0081 (11)0.0110 (10)0.0130 (11)
C90.0648 (12)0.0620 (12)0.0864 (14)0.0074 (9)0.0408 (11)0.0119 (10)
C100.0563 (10)0.0460 (10)0.0424 (8)0.0067 (8)0.0244 (7)0.0056 (7)
Geometric parameters (Å, º) top
O1—C101.234 (2)C3—H30.9300
O2—C101.282 (2)C4—H4A0.9700
O2—H2A1.01 (4)C4—H4B0.9700
C1—C61.551 (2)C5—H5A0.9700
C1—C101.519 (2)C5—H5B0.9700
C1—C21.516 (2)C7—H7A0.9600
C2—C71.503 (3)C7—H7B0.9600
C2—C31.324 (3)C7—H7C0.9600
C3—C41.486 (3)C8—H8A0.9600
C4—C51.513 (3)C8—H8B0.9600
C5—C61.530 (3)C8—H8C0.9600
C6—C81.531 (3)C9—H9A0.9600
C6—C91.540 (3)C9—H9B0.9600
C1—H10.971 (17)C9—H9C0.9600
O1···C53.133 (2)H2A···O1i1.64 (4)
O1···C83.418 (3)H2A···O2i2.81 (4)
O1···C10i3.382 (2)H2A···C10i2.52 (4)
O1···O2i2.646 (2)H2A···H2Ai2.28 (6)
O2···O1i2.646 (2)H3···H7C2.3200
O2···C83.403 (3)H3···C3iii3.0700
O1···H8B2.8700H4A···O2iv2.7900
O1···H2Ai1.64 (4)H4B···C92.8600
O1···H5A2.5000H4B···H9A2.4200
O2···H4Aii2.7900H5A···O12.5000
O2···H2Ai2.81 (4)H5A···C102.8800
C3···C93.288 (3)H5A···H8B2.4700
C3···C3iii3.555 (2)H5B···H8C2.5300
C5···O13.133 (2)H5B···H9C2.5000
C8···O23.403 (3)H7A···C102.8500
C8···O13.418 (3)H7B···H12.4900
C9···C33.288 (3)H7C···H32.3200
C10···O1i3.382 (2)H8A···C103.0300
C2···H9A2.7300H8A···H9B2.4800
C3···H3iii3.0700H8B···O12.8700
C3···H1iv3.018 (17)H8B···C102.5800
C3···H9A2.7600H8B···H5A2.4700
C4···H9A2.7000H8C···H5B2.5300
C9···H4B2.8600H8C···H9C2.5200
C10···H5A2.8800H9A···C22.7300
C10···H8A3.0300H9A···C32.7600
C10···H8B2.5800H9A···C42.7000
C10···H7A2.8500H9A···H4B2.4200
C10···H2Ai2.52 (4)H9B···H12.4100
H1···H7B2.4900H9B···H8A2.4800
H1···H9B2.4100H9C···H5B2.5000
H1···C3ii3.018 (17)H9C···H8C2.5200
C10—O2—H2A113 (2)C5—C4—H4A109.00
C2—C1—C10108.68 (13)C5—C4—H4B109.00
C6—C1—C10112.58 (13)H4A—C4—H4B108.00
C2—C1—C6112.73 (13)C4—C5—H5A109.00
C1—C2—C7115.59 (15)C4—C5—H5B109.00
C3—C2—C7123.07 (16)C6—C5—H5A109.00
C1—C2—C3121.34 (16)C6—C5—H5B109.00
C2—C3—C4125.20 (16)H5A—C5—H5B108.00
C3—C4—C5113.21 (17)C2—C7—H7A109.00
C4—C5—C6112.80 (15)C2—C7—H7B109.00
C1—C6—C5109.32 (14)C2—C7—H7C109.00
C1—C6—C8110.71 (15)H7A—C7—H7B110.00
C5—C6—C8110.10 (15)H7A—C7—H7C110.00
C5—C6—C9110.39 (15)H7B—C7—H7C109.00
C8—C6—C9109.00 (16)C6—C8—H8A109.00
C1—C6—C9107.28 (15)C6—C8—H8B109.00
O1—C10—C1121.53 (15)C6—C8—H8C109.00
O2—C10—C1115.97 (15)H8A—C8—H8B109.00
O1—C10—O2122.50 (16)H8A—C8—H8C109.00
C2—C1—H1108.3 (9)H8B—C8—H8C109.00
C6—C1—H1108.2 (10)C6—C9—H9A109.00
C10—C1—H1106.1 (9)C6—C9—H9B109.00
C2—C3—H3117.00C6—C9—H9C109.00
C4—C3—H3117.00H9A—C9—H9B109.00
C3—C4—H4A109.00H9A—C9—H9C110.00
C3—C4—H4B109.00H9B—C9—H9C109.00
C6—C1—C2—C320.0 (2)C2—C1—C10—O2120.32 (16)
C6—C1—C2—C7159.84 (15)C6—C1—C10—O167.1 (2)
C10—C1—C2—C3105.55 (18)C6—C1—C10—O2114.07 (17)
C10—C1—C2—C774.64 (18)C1—C2—C3—C41.5 (3)
C2—C1—C6—C546.66 (18)C7—C2—C3—C4178.26 (18)
C2—C1—C6—C8168.11 (14)C2—C3—C4—C511.4 (3)
C2—C1—C6—C973.06 (18)C3—C4—C5—C639.9 (2)
C10—C1—C6—C576.73 (17)C4—C5—C6—C157.77 (19)
C10—C1—C6—C844.72 (19)C4—C5—C6—C8179.60 (17)
C10—C1—C6—C9163.55 (14)C4—C5—C6—C960.0 (2)
C2—C1—C10—O158.5 (2)
Symmetry codes: (i) x+1, y+1, z+1; (ii) x+1, y1/2, z+1/2; (iii) x+1, y+1, z; (iv) x+1, y+1/2, z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H2A···O1i1.01 (4)1.64 (4)2.646 (2)178 (4)
C5—H5A···O10.972.503.133 (2)122
Symmetry code: (i) x+1, y+1, z+1.

Experimental details

Crystal data
Chemical formulaC10H16O2
Mr168.23
Crystal system, space groupMonoclinic, P21/c
Temperature (K)296
a, b, c (Å)7.6817 (1), 10.4137 (2), 13.4421 (2)
β (°) 112.924 (1)
V3)990.38 (3)
Z4
Radiation typeMo Kα
µ (mm1)0.08
Crystal size (mm)0.09 × 0.08 × 0.05
Data collection
DiffractometerBruker SMART APEXII CCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2008)
Tmin, Tmax0.993, 0.996
No. of measured, independent and
observed [I > 2σ(I)] reflections
10045, 2158, 1560
Rint0.026
(sin θ/λ)max1)0.638
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.049, 0.134, 1.03
No. of reflections2158
No. of parameters120
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.25, 0.17

Computer programs: APEX2 (Bruker, 2008), SAINT (Bruker, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H2A···O1i1.01 (4)1.64 (4)2.646 (2)178 (4)
Symmetry code: (i) x+1, y+1, z+1.
 

Acknowledgements

PTM and SJJ thank the DST India (FIST programme) for the use of the diffractometer at the School of Chemistry, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India.

References

First citationBernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573.  CrossRef CAS Web of Science
First citationBruker (2008). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.
First citationEtter, M. C., MacDonald, J. C. & Bernstein, J. (1990). Acta Cryst. B46, 256–262.  CrossRef CAS Web of Science IUCr Journals
First citationEugster, C. H., Buchecker, R., Tscharner, C., Uhde, G. & Ohloff, G. (1969). Helv. Chim. Acta, 52, 1729–1731.  CrossRef CAS
First citationFehr, C. & Galindo, J. (1986). Helv. Chim. Acta, 69, 228-235.  CrossRef CAS
First citationFehr, C. & Galindo, J. (1995). Helv. Chim. Acta, 78, 539-552.  CrossRef CAS
First citationHeather, J. B., Mittal, R. S. D. & Sih, C. J. (1976). J. Am. Chem. Soc. 98, 3661–3669.  CrossRef CAS
First citationNaef, F. & Decorzant, R. (1986). Tetrahedron, 42, 3245-3250.  CrossRef CAS
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals
First citationSnowden, R. L., Muller, B. L. & Schulte-Elte, K. H. (1982). Tetrahedron Lett. 23, 335–338.  CrossRef CAS
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds