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

Parthasarathy, R.; Jenniefer, S.J.; Thomas Muthiah, P.; Sulochana, N.

doi:10.1107/S1600536812002668

organic compounds

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ISSN: 2056-9890

Volume 68| Part 2| February 2012| Page o536

doi:10.1107/S1600536812002668

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

Rajasekaran Parthasarathy,^a Samson Jegan Jenniefer,^b Packianathan Thomas Muthiah ^b ^* and Nagarajan Sulochana ^c

^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 ); 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

Crystal data

C₁₀H₁₆O₂
M_r = 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 ) T_min = 0.993, T_max = 0.996
10045 measured reflections
2158 independent reflections
1560 reflections with I > 2σ(I)
R_int = 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
Δρ_max = 0.25 e Å⁻³
Δρ_min = −0.17 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	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); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT; 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.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536812002668/lh5406sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812002668/lh5406Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536812002668/lh5406Isup3.cml

checkCIF report

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.

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

	Fig. 1. The molecular structure of the title compound, with anisotropic displacement ellipsoids drawn at 50% probability level.
	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

C₁₀H₁₆O₂	F(000) = 368
M_r = 168.23	D_x = 1.128 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3232 reflections
a = 7.6817 (1) Å	θ = 2.9–25.1°
b = 10.4137 (2) Å	µ = 0.08 mm⁻¹
c = 13.4421 (2) Å	T = 296 K
β = 112.924 (1)°	Prism, colourless
V = 990.38 (3) Å³	0.09 × 0.08 × 0.05 mm
Z = 4

Data collection top

Bruker SMART APEXII CCD diffractometer	2158 independent reflections
Radiation source: fine-focus sealed tube	1560 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.026
ϕ and ω scans	θ_max = 27.0°, θ_min = 2.6°
Absorption correction: multi-scan (SADABS; Bruker, 2008)	h = −9→8
T_min = 0.993, T_max = 0.996	k = −13→8
10045 measured reflections	l = −17→17

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.049	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.134	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ²(F_o²) + (0.0541P)² + 0.2979P] where P = (F_o² + 2F_c²)/3
2158 reflections	(Δ/σ)_max = 0.003
120 parameters	Δρ_max = 0.25 e Å⁻³
0 restraints	Δρ_min = −0.17 e Å⁻³

Crystal data top

C₁₀H₁₆O₂	V = 990.38 (3) Å³
M_r = 168.23	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 7.6817 (1) Å	µ = 0.08 mm⁻¹
b = 10.4137 (2) Å	T = 296 K
c = 13.4421 (2) Å	0.09 × 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)
T_min = 0.993, T_max = 0.996	R_int = 0.026
10045 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.049	0 restraints
wR(F²) = 0.134	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	Δρ_max = 0.25 e Å⁻³
2158 reflections	Δρ_min = −0.17 e Å⁻³
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

	x	y	z	U_iso*/U_eq
O1	0.5749 (2)	0.54166 (13)	0.40375 (11)	0.0729 (6)
O2	0.4766 (2)	0.35104 (14)	0.43135 (12)	0.0793 (6)
C1	0.5737 (2)	0.36939 (16)	0.28421 (12)	0.0432 (5)
C2	0.4543 (2)	0.44209 (16)	0.18282 (12)	0.0464 (5)
C3	0.5312 (3)	0.52452 (17)	0.13678 (13)	0.0531 (6)
C4	0.7364 (3)	0.5534 (2)	0.17489 (16)	0.0612 (7)
C5	0.8506 (2)	0.49910 (18)	0.28571 (15)	0.0548 (6)
C6	0.7857 (2)	0.36479 (17)	0.30219 (13)	0.0495 (5)
C7	0.2461 (3)	0.4137 (2)	0.13917 (17)	0.0723 (8)
C8	0.9058 (3)	0.3161 (2)	0.41584 (17)	0.0770 (8)
C9	0.8045 (3)	0.2706 (2)	0.21865 (18)	0.0676 (7)
C10	0.5421 (2)	0.42734 (16)	0.37950 (12)	0.0467 (5)
H1	0.527 (2)	0.2818 (16)	0.2775 (12)	0.042 (4)*
H2A	0.459 (5)	0.394 (4)	0.494 (3)	0.167 (13)*
H3	0.45030	0.56780	0.07570	0.0640*
H4A	0.75350	0.64580	0.17680	0.0730*
H4B	0.78430	0.51850	0.12360	0.0730*
H5A	0.84030	0.55630	0.34010	0.0660*
H5B	0.98260	0.49550	0.29580	0.0660*
H7A	0.19700	0.43390	0.19300	0.1080*
H7B	0.22580	0.32430	0.12080	0.1080*
H7C	0.18260	0.46470	0.07580	0.1080*
H8A	0.85880	0.23430	0.42710	0.1160*
H8B	0.89920	0.37630	0.46830	0.1160*
H8C	1.03480	0.30720	0.42340	0.1160*
H9A	0.72010	0.29590	0.14750	0.1010*
H9B	0.77290	0.18550	0.23350	0.1010*
H9C	0.93220	0.27160	0.22290	0.1010*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.1202 (12)	0.0524 (8)	0.0696 (9)	−0.0172 (8)	0.0626 (9)	−0.0177 (6)
O2	0.1320 (14)	0.0630 (9)	0.0742 (9)	−0.0294 (8)	0.0741 (10)	−0.0186 (7)
C1	0.0504 (9)	0.0410 (9)	0.0432 (8)	−0.0068 (7)	0.0238 (7)	−0.0081 (6)
C2	0.0455 (9)	0.0551 (10)	0.0408 (8)	−0.0020 (7)	0.0193 (7)	−0.0111 (7)
C3	0.0575 (10)	0.0604 (11)	0.0418 (8)	0.0047 (8)	0.0199 (8)	0.0005 (7)
C4	0.0651 (12)	0.0624 (12)	0.0653 (11)	−0.0064 (9)	0.0354 (10)	0.0043 (9)
C5	0.0451 (9)	0.0597 (11)	0.0611 (10)	−0.0083 (8)	0.0222 (8)	−0.0074 (8)
C6	0.0454 (9)	0.0515 (10)	0.0516 (9)	0.0014 (7)	0.0190 (7)	−0.0027 (7)
C7	0.0501 (11)	0.0970 (16)	0.0650 (12)	−0.0081 (10)	0.0172 (9)	−0.0101 (11)
C8	0.0661 (13)	0.0828 (15)	0.0682 (12)	0.0081 (11)	0.0110 (10)	0.0130 (11)
C9	0.0648 (12)	0.0620 (12)	0.0864 (14)	0.0074 (9)	0.0408 (11)	−0.0119 (10)
C10	0.0563 (10)	0.0460 (10)	0.0424 (8)	−0.0067 (8)	0.0244 (7)	−0.0056 (7)

Geometric parameters (Å, º) top

O1—C10	1.234 (2)	C3—H3	0.9300
O2—C10	1.282 (2)	C4—H4A	0.9700
O2—H2A	1.01 (4)	C4—H4B	0.9700
C1—C6	1.551 (2)	C5—H5A	0.9700
C1—C10	1.519 (2)	C5—H5B	0.9700
C1—C2	1.516 (2)	C7—H7A	0.9600
C2—C7	1.503 (3)	C7—H7B	0.9600
C2—C3	1.324 (3)	C7—H7C	0.9600
C3—C4	1.486 (3)	C8—H8A	0.9600
C4—C5	1.513 (3)	C8—H8B	0.9600
C5—C6	1.530 (3)	C8—H8C	0.9600
C6—C8	1.531 (3)	C9—H9A	0.9600
C6—C9	1.540 (3)	C9—H9B	0.9600
C1—H1	0.971 (17)	C9—H9C	0.9600

O1···C5	3.133 (2)	H2A···O1ⁱ	1.64 (4)
O1···C8	3.418 (3)	H2A···O2ⁱ	2.81 (4)
O1···C10ⁱ	3.382 (2)	H2A···C10ⁱ	2.52 (4)
O1···O2ⁱ	2.646 (2)	H2A···H2Aⁱ	2.28 (6)
O2···O1ⁱ	2.646 (2)	H3···H7C	2.3200
O2···C8	3.403 (3)	H3···C3ⁱⁱⁱ	3.0700
O1···H8B	2.8700	H4A···O2^iv	2.7900
O1···H2Aⁱ	1.64 (4)	H4B···C9	2.8600
O1···H5A	2.5000	H4B···H9A	2.4200
O2···H4Aⁱⁱ	2.7900	H5A···O1	2.5000
O2···H2Aⁱ	2.81 (4)	H5A···C10	2.8800
C3···C9	3.288 (3)	H5A···H8B	2.4700
C3···C3ⁱⁱⁱ	3.555 (2)	H5B···H8C	2.5300
C5···O1	3.133 (2)	H5B···H9C	2.5000
C8···O2	3.403 (3)	H7A···C10	2.8500
C8···O1	3.418 (3)	H7B···H1	2.4900
C9···C3	3.288 (3)	H7C···H3	2.3200
C10···O1ⁱ	3.382 (2)	H8A···C10	3.0300
C2···H9A	2.7300	H8A···H9B	2.4800
C3···H3ⁱⁱⁱ	3.0700	H8B···O1	2.8700
C3···H1^iv	3.018 (17)	H8B···C10	2.5800
C3···H9A	2.7600	H8B···H5A	2.4700
C4···H9A	2.7000	H8C···H5B	2.5300
C9···H4B	2.8600	H8C···H9C	2.5200
C10···H5A	2.8800	H9A···C2	2.7300
C10···H8A	3.0300	H9A···C3	2.7600
C10···H8B	2.5800	H9A···C4	2.7000
C10···H7A	2.8500	H9A···H4B	2.4200
C10···H2Aⁱ	2.52 (4)	H9B···H1	2.4100
H1···H7B	2.4900	H9B···H8A	2.4800
H1···H9B	2.4100	H9C···H5B	2.5000
H1···C3ⁱⁱ	3.018 (17)	H9C···H8C	2.5200

C10—O2—H2A	113 (2)	C5—C4—H4A	109.00
C2—C1—C10	108.68 (13)	C5—C4—H4B	109.00
C6—C1—C10	112.58 (13)	H4A—C4—H4B	108.00
C2—C1—C6	112.73 (13)	C4—C5—H5A	109.00
C1—C2—C7	115.59 (15)	C4—C5—H5B	109.00
C3—C2—C7	123.07 (16)	C6—C5—H5A	109.00
C1—C2—C3	121.34 (16)	C6—C5—H5B	109.00
C2—C3—C4	125.20 (16)	H5A—C5—H5B	108.00
C3—C4—C5	113.21 (17)	C2—C7—H7A	109.00
C4—C5—C6	112.80 (15)	C2—C7—H7B	109.00
C1—C6—C5	109.32 (14)	C2—C7—H7C	109.00
C1—C6—C8	110.71 (15)	H7A—C7—H7B	110.00
C5—C6—C8	110.10 (15)	H7A—C7—H7C	110.00
C5—C6—C9	110.39 (15)	H7B—C7—H7C	109.00
C8—C6—C9	109.00 (16)	C6—C8—H8A	109.00
C1—C6—C9	107.28 (15)	C6—C8—H8B	109.00
O1—C10—C1	121.53 (15)	C6—C8—H8C	109.00
O2—C10—C1	115.97 (15)	H8A—C8—H8B	109.00
O1—C10—O2	122.50 (16)	H8A—C8—H8C	109.00
C2—C1—H1	108.3 (9)	H8B—C8—H8C	109.00
C6—C1—H1	108.2 (10)	C6—C9—H9A	109.00
C10—C1—H1	106.1 (9)	C6—C9—H9B	109.00
C2—C3—H3	117.00	C6—C9—H9C	109.00
C4—C3—H3	117.00	H9A—C9—H9B	109.00
C3—C4—H4A	109.00	H9A—C9—H9C	110.00
C3—C4—H4B	109.00	H9B—C9—H9C	109.00

C6—C1—C2—C3	−20.0 (2)	C2—C1—C10—O2	120.32 (16)
C6—C1—C2—C7	159.84 (15)	C6—C1—C10—O1	67.1 (2)
C10—C1—C2—C3	105.55 (18)	C6—C1—C10—O2	−114.07 (17)
C10—C1—C2—C7	−74.64 (18)	C1—C2—C3—C4	1.5 (3)
C2—C1—C6—C5	46.66 (18)	C7—C2—C3—C4	−178.26 (18)
C2—C1—C6—C8	168.11 (14)	C2—C3—C4—C5	−11.4 (3)
C2—C1—C6—C9	−73.06 (18)	C3—C4—C5—C6	39.9 (2)
C10—C1—C6—C5	−76.73 (17)	C4—C5—C6—C1	−57.77 (19)
C10—C1—C6—C8	44.72 (19)	C4—C5—C6—C8	−179.60 (17)
C10—C1—C6—C9	163.55 (14)	C4—C5—C6—C9	60.0 (2)
C2—C1—C10—O1	−58.5 (2)

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+1, y−1/2, −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···A	D—H	H···A	D···A	D—H···A
O2—H2A···O1ⁱ	1.01 (4)	1.64 (4)	2.646 (2)	178 (4)
C5—H5A···O1	0.97	2.50	3.133 (2)	122

Symmetry code: (i) −x+1, −y+1, −z+1.

Experimental details

Crystal data
Chemical formula	C₁₀H₁₆O₂
M_r	168.23
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	296
a, b, c (Å)	7.6817 (1), 10.4137 (2), 13.4421 (2)
β (°)	112.924 (1)
V (Å³)	990.38 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.08
Crystal size (mm)	0.09 × 0.08 × 0.05

Data collection
Diffractometer	Bruker SMART APEXII CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2008)
T_min, T_max	0.993, 0.996
No. of measured, independent and observed [I > 2σ(I)] reflections	10045, 2158, 1560
R_int	0.026
(sin θ/λ)_max (Å⁻¹)	0.638

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.049, 0.134, 1.03
No. of reflections	2158
No. of parameters	120
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	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···A	D—H	H···A	D···A	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.

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

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