(E)-Isopentyl 3-(3,4-dihy­droxy­phen­yl)­acrylate

Gu, S.-S.; Wang, J.; Pan, F.; Pang, N.; Wu, F.-A.

doi:10.1107/S1600536812003352

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 68| Part 3| March 2012| Page o557

doi:10.1107/S1600536812003352

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(E)-Isopentyl 3-(3,4-dihydroxyphenyl)acrylate

Shuang-Shuang Gu,^a Jun Wang,^a ^* Fei Pan,^a Na Pang ^a and Fu-An Wu ^a,^b

^aSchool of Biological and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212018, People's Republic of China, and ^bSericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212018, People's Republic of China
^*Correspondence e-mail: jimwang_js@hotmail.com

(Received 14 January 2012; accepted 26 January 2012; online 4 February 2012)

The title compound, C₁₄H₁₈O₄, a derivative of caffeic acid, has an E configuration about the C=C bond. The benzene ring is almost coplanar with the C=C—C(O)—O—C linker [maximum deviation = 0.050 (2) Å], making a dihedral angle of only 4.53 (2)°. In the molecule, the adjacent hydroxy groups form an O—H⋯O interaction. In the crystal, molecules are linked by O—H⋯O hydrogen bonds, generating a chain propagating in the [110] direction.

Related literature

For the biological properties of caffeic acid esters, see: Buzzi et al. (2009 ); Uwai et al. (2008 ). For synthetic details, see: Feng et al. (2011 ); Wang et al. (2011 ). For related structures, see: Xia et al. (2004 , 2006 ); Wang et al. (2011).

Experimental

Crystal data

C₁₄H₁₈O₄
M_r = 250.28
Triclinic, $[P \overline 1]$
a = 5.2790 (11) Å
b = 10.244 (2) Å
c = 13.834 (3) Å
α = 69.05 (3)°
β = 80.11 (3)°
γ = 78.79 (3)°
V = 681.0 (2) Å³
Z = 2
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 293 K
0.30 × 0.20 × 0.10 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: ψ scan (North et al., 1968 ) T_min = 0.974, T_max = 0.991
2507 measured reflections
2507 independent reflections
1300 reflections with I > 2σ(I)
3 standard reflections every 200 min intensity decay: 1%

Refinement

R[F² > 2σ(F²)] = 0.059
wR(F²) = 0.156
S = 1.00
2507 reflections
163 parameters
2 restraints
H-atom parameters constrained
Δρ_max = 0.14 e Å⁻³
Δρ_min = −0.14 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O4—H4A⋯O3	0.82	2.28	2.721 (2)	114
O3—H3A⋯O1ⁱ	0.82	1.95	2.764 (2)	173
O4—H4A⋯O3ⁱⁱ	0.82	2.13	2.831 (2)	143
Symmetry codes: (i) -x, -y+1, -z+1; (ii) -x+1, -y+2, -z+1.

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994 ); cell refinement: CAD-4 EXPRESS; 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: PLATON (Spek, 2009 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536812003352/su2370sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812003352/su2370Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536812003352/su2370Isup3.cml

checkCIF report

Comment top

Caffeic acid esters are a component of propolis (a vegetable resin) and are reported to have a broad spectrum of biological effects, such as, anti-tumour, antioxidant, and anti-inflammatory activities (Uwai et al., 2008; Buzzi et al., 2009). The resin itself has been used as a cation-exchange resin for heterogeneous catalyst (Feng et al., 2011). This prompted us to synthesize a series of caffeic acid esters to investigate their properties better (Wang et al., 2011). Herein, we report on the crystal structure of the title compound, the isopentyl derivative of caffeic acid.

The title molecule has an E configuration about the C7═C8 bond (Fig. 1). The benzene ring with the C7═C8—C9 linker is almost coplanar, with a root mean square deviation from the mean plane of 0.005 Å. All bond lengths and angles are in very close agreement with those found in similar caffeic acid structures (Xia et al., 2004, 2006), and in the pentyl derivative of caffeic acid (Wang et al., 2011).

In the crystal, the hydroxy groups contribute to intermolecular O—H···O interactions (Table 1), that link the molecules into ribbons extending in the [110] direction (Fig. 2). On the other hand, the intramolecular O—H···O H-bond also contributes to the stability of the molecular configuration (Fig. 1 and Table 1).

Related literature top

For the biological properties of caffeic acid esters, see: Buzzi et al. (2009); Uwai et al. (2008). For synthetic details, see: Feng et al. (2011); Wang et al. (2011). For related structures, see: Xia et al. (2004, 2006); Wang et al. (2011).

Experimental top

The synthesis follows the method of (Wang et al., 2011). Esterification of caffeic acid with hexyl alcohol was performed in a column (inner diameter = 15 mm, length = 200 mm). A cation exchange resin CD-552 particles (5 g) molecular sieve (5 g) and glass beads of 2 mm in diameter were packed into the middle of the reactor. In a reaction mixture tank, 9 g of caffeic acid was mixed with 100 ml hexyl alcohol. The reaction mixture was supplied to the reaction column at a aret of 10.0 ml/h. The reaction continued at 353 K for 24 h. The solvent was then removed under reduced pressure. The residue was extracted with ethyl acetate three times and filtered. The filtrate was washed successively with dilute saturated aqueous NaHCO₃ solution, saturated aqueous NaCl, then dried over MgSO₄, and evaporated. The residue was recrystallized from ethanol to give the title compound as colourless crystals (Yield 5.2 g; 57.7%).

Computing details top

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: CAD-4 EXPRESS (Enraf–Nonius, 1994); 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: PLATON (Spek, 2009).

Figures top

	Fig. 1. The molecular structure of the title molecule, with the atom numbering scheme and displacement ellipsoids drawn at the 30% probability level.
	Fig. 2. A view along the a-axis of the crystal packing of the title compound. Hydrogen bonds are shown as dashed lines - see Table 1 for details.

(E)-Isopentyl 3-(3,4-dihydroxyphenyl)acrylate top

Crystal data top

C₁₄H₁₈O₄	Z = 2
M_r = 250.28	F(000) = 268
Triclinic, P1	D_x = 1.220 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 5.2790 (11) Å	Cell parameters from 25 reflections
b = 10.244 (2) Å	θ = 9–13°
c = 13.834 (3) Å	µ = 0.09 mm⁻¹
α = 69.05 (3)°	T = 293 K
β = 80.11 (3)°	Block, colourless
γ = 78.79 (3)°	0.30 × 0.20 × 0.10 mm
V = 681.0 (2) Å³

Data collection top

Enraf–Nonius CAD-4 diffractometer	1300 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.000
Graphite monochromator	θ_max = 25.4°, θ_min = 1.6°
ω/2θ scans	h = −6→6
Absorption correction: ψ scan (North et al., 1968)	k = −11→12
T_min = 0.974, T_max = 0.991	l = 0→16
2507 measured reflections	3 standard reflections every 200 min
2507 independent reflections	intensity decay: 1%

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)] = 0.059	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.156	H-atom parameters constrained
S = 1.00	w = 1/[σ²(F_o²) + (0.070P)²] where P = (F_o² + 2F_c²)/3
2507 reflections	(Δ/σ)_max < 0.001
163 parameters	Δρ_max = 0.14 e Å⁻³
2 restraints	Δρ_min = −0.14 e Å⁻³

Crystal data top

C₁₄H₁₈O₄	γ = 78.79 (3)°
M_r = 250.28	V = 681.0 (2) Å³
Triclinic, P1	Z = 2
a = 5.2790 (11) Å	Mo Kα radiation
b = 10.244 (2) Å	µ = 0.09 mm⁻¹
c = 13.834 (3) Å	T = 293 K
α = 69.05 (3)°	0.30 × 0.20 × 0.10 mm
β = 80.11 (3)°

Data collection top

Enraf–Nonius CAD-4 diffractometer	1300 reflections with I > 2σ(I)
Absorption correction: ψ scan (North et al., 1968)	R_int = 0.000
T_min = 0.974, T_max = 0.991	3 standard reflections every 200 min
2507 measured reflections	intensity decay: 1%
2507 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.059	2 restraints
wR(F²) = 0.156	H-atom parameters constrained
S = 1.00	Δρ_max = 0.14 e Å⁻³
2507 reflections	Δρ_min = −0.14 e Å⁻³
163 parameters

Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) 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
C1	0.2966 (5)	0.6252 (2)	0.56768 (18)	0.0557 (7)
H1A	0.1700	0.6372	0.5248	0.067*
O1	−0.0024 (4)	0.16077 (18)	0.62733 (15)	0.0877 (7)
O2	0.1887 (4)	0.01321 (17)	0.76260 (13)	0.0743 (6)
C2	0.4057 (5)	0.7386 (2)	0.55959 (18)	0.0543 (7)
O3	0.3407 (3)	0.87217 (15)	0.49143 (12)	0.0658 (6)
H3A	0.2404	0.8698	0.4531	0.099*
C3	0.5921 (5)	0.7242 (2)	0.62374 (18)	0.0561 (7)
O4	0.7014 (4)	0.83462 (17)	0.62142 (14)	0.0793 (7)
H4A	0.6432	0.9064	0.5765	0.119*
C4	0.6631 (5)	0.5938 (2)	0.6955 (2)	0.0663 (8)
H4B	0.7863	0.5837	0.7393	0.080*
C5	0.5533 (5)	0.4770 (3)	0.70355 (19)	0.0666 (8)
H5A	0.6029	0.3894	0.7523	0.080*
C6	0.3678 (5)	0.4917 (2)	0.63792 (17)	0.0530 (7)
C7	0.2509 (5)	0.3738 (2)	0.63921 (18)	0.0570 (7)
H7A	0.1330	0.3959	0.5909	0.068*
C8	0.2875 (5)	0.2395 (2)	0.69908 (18)	0.0610 (7)
H8A	0.4077	0.2102	0.7472	0.073*
C9	0.1449 (5)	0.1375 (2)	0.69123 (18)	0.0541 (7)
C10	0.0528 (7)	−0.0973 (3)	0.7622 (2)	0.0821 (10)
H10A	0.1149	−0.1228	0.7003	0.099*
H10B	−0.1322	−0.0639	0.7620	0.099*
C11	0.1015 (8)	−0.2212 (3)	0.8563 (2)	0.1123 (13)
H11A	0.0061	−0.2928	0.8556	0.135*
H11B	0.2847	−0.2584	0.8493	0.135*
C12	0.0392 (9)	−0.2063 (4)	0.9575 (2)	0.1090 (13)
H12A	0.1470	−0.1399	0.9599	0.131*
C13	0.1016 (11)	−0.3421 (5)	1.0451 (3)	0.171 (2)
H13A	0.2824	−0.3785	1.0352	0.256*
H13B	−0.0021	−0.4098	1.0459	0.256*
H13C	0.0644	−0.3247	1.1102	0.256*
C14	−0.2487 (11)	−0.1421 (5)	0.9771 (4)	0.179 (2)
H14A	−0.2887	−0.0562	0.9206	0.268*
H14B	−0.2751	−0.1222	1.0411	0.268*
H14C	−0.3602	−0.2082	0.9815	0.268*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0686 (18)	0.0450 (14)	0.0592 (15)	−0.0190 (13)	−0.0249 (13)	−0.0107 (12)
O1	0.1255 (19)	0.0556 (11)	0.0918 (14)	−0.0350 (11)	−0.0638 (14)	−0.0015 (10)
O2	0.1147 (17)	0.0505 (11)	0.0639 (11)	−0.0347 (10)	−0.0391 (11)	−0.0014 (9)
C2	0.0689 (18)	0.0438 (14)	0.0547 (14)	−0.0209 (13)	−0.0223 (13)	−0.0083 (12)
O3	0.0876 (14)	0.0435 (10)	0.0711 (11)	−0.0261 (9)	−0.0368 (10)	−0.0037 (8)
C3	0.0700 (18)	0.0471 (14)	0.0576 (14)	−0.0250 (13)	−0.0186 (13)	−0.0116 (12)
O4	0.1004 (16)	0.0569 (11)	0.0944 (14)	−0.0368 (11)	−0.0507 (11)	−0.0107 (10)
C4	0.080 (2)	0.0540 (16)	0.0741 (17)	−0.0224 (14)	−0.0340 (15)	−0.0142 (14)
C5	0.087 (2)	0.0486 (15)	0.0666 (16)	−0.0247 (14)	−0.0390 (15)	−0.0004 (12)
C6	0.0623 (17)	0.0493 (14)	0.0529 (14)	−0.0235 (13)	−0.0112 (12)	−0.0135 (12)
C7	0.0710 (19)	0.0493 (15)	0.0549 (14)	−0.0226 (13)	−0.0237 (13)	−0.0076 (12)
C8	0.079 (2)	0.0495 (15)	0.0574 (15)	−0.0228 (14)	−0.0284 (14)	−0.0048 (12)
C9	0.0681 (19)	0.0418 (14)	0.0534 (14)	−0.0161 (13)	−0.0183 (13)	−0.0078 (12)
C10	0.143 (3)	0.0514 (16)	0.0632 (16)	−0.0484 (17)	−0.0326 (17)	−0.0050 (13)
C11	0.183 (4)	0.069 (2)	0.092 (2)	−0.058 (2)	−0.050 (2)	0.0008 (18)
C12	0.120 (3)	0.126 (3)	0.073 (2)	−0.055 (3)	−0.016 (2)	−0.0006 (19)
C13	0.223 (6)	0.145 (4)	0.123 (3)	−0.028 (4)	−0.040 (3)	−0.009 (3)
C14	0.171 (6)	0.200 (6)	0.160 (5)	−0.019 (4)	−0.014 (4)	−0.060 (4)

Geometric parameters (Å, º) top

C1—C2	1.356 (3)	C7—H7A	0.9300
C1—C6	1.390 (3)	C8—C9	1.444 (3)
C1—H1A	0.9300	C8—H8A	0.9300
O1—C9	1.207 (3)	C10—C11	1.476 (3)
O2—C9	1.310 (3)	C10—H10A	0.9700
O2—C10	1.455 (3)	C10—H10B	0.9700
C2—O3	1.373 (3)	C11—C12	1.439 (5)
C2—C3	1.388 (3)	C11—H11A	0.9700
O3—H3A	0.8200	C11—H11B	0.9700
C3—O4	1.355 (3)	C12—C13	1.505 (5)
C3—C4	1.377 (3)	C12—C14	1.553 (6)
O4—H4A	0.8200	C12—H12A	0.9800
C4—C5	1.390 (3)	C13—H13A	0.9600
C4—H4B	0.9300	C13—H13B	0.9600
C5—C6	1.398 (3)	C13—H13C	0.9600
C5—H5A	0.9300	C14—H14A	0.9600
C6—C7	1.453 (3)	C14—H14B	0.9600
C7—C8	1.324 (3)	C14—H14C	0.9600

C2—C1—C6	122.1 (2)	O2—C10—C11	108.5 (2)
C2—C1—H1A	118.9	O2—C10—H10A	110.0
C6—C1—H1A	118.9	C11—C10—H10A	110.0
C9—O2—C10	117.5 (2)	O2—C10—H10B	110.0
C1—C2—O3	124.0 (2)	C11—C10—H10B	110.0
C1—C2—C3	120.1 (2)	H10A—C10—H10B	108.4
O3—C2—C3	115.9 (2)	C12—C11—C10	119.8 (3)
C2—O3—H3A	109.5	C12—C11—H11A	107.4
O4—C3—C4	118.2 (2)	C10—C11—H11A	107.4
O4—C3—C2	122.6 (2)	C12—C11—H11B	107.4
C4—C3—C2	119.1 (2)	C10—C11—H11B	107.4
C3—O4—H4A	109.5	H11A—C11—H11B	106.9
C3—C4—C5	121.0 (2)	C11—C12—C13	113.3 (4)
C3—C4—H4B	119.5	C11—C12—C14	112.5 (4)
C5—C4—H4B	119.5	C13—C12—C14	109.6 (3)
C4—C5—C6	119.7 (2)	C11—C12—H12A	107.0
C4—C5—H5A	120.1	C13—C12—H12A	107.0
C6—C5—H5A	120.1	C14—C12—H12A	107.0
C1—C6—C5	117.9 (2)	C12—C13—H13A	109.5
C1—C6—C7	119.1 (2)	C12—C13—H13B	109.5
C5—C6—C7	122.9 (2)	H13A—C13—H13B	109.5
C8—C7—C6	129.5 (2)	C12—C13—H13C	109.5
C8—C7—H7A	115.3	H13A—C13—H13C	109.5
C6—C7—H7A	115.3	H13B—C13—H13C	109.5
C7—C8—C9	121.4 (2)	C12—C14—H14A	109.5
C7—C8—H8A	119.3	C12—C14—H14B	109.5
C9—C8—H8A	119.3	H14A—C14—H14B	109.5
O1—C9—O2	121.8 (2)	C12—C14—H14C	109.5
O1—C9—C8	125.2 (2)	H14A—C14—H14C	109.5
O2—C9—C8	113.0 (2)	H14B—C14—H14C	109.5

C6—C1—C2—O3	−179.9 (2)	C4—C5—C6—C7	177.9 (3)
C6—C1—C2—C3	−1.0 (4)	C1—C6—C7—C8	−179.5 (3)
C1—C2—C3—O4	−177.8 (3)	C5—C6—C7—C8	1.5 (4)
O3—C2—C3—O4	1.2 (4)	C6—C7—C8—C9	177.8 (3)
C1—C2—C3—C4	−0.3 (4)	C10—O2—C9—O1	0.1 (4)
O3—C2—C3—C4	178.7 (2)	C10—O2—C9—C8	179.5 (2)
O4—C3—C4—C5	178.4 (3)	C7—C8—C9—O1	5.2 (4)
C2—C3—C4—C5	0.8 (4)	C7—C8—C9—O2	−174.1 (2)
C3—C4—C5—C6	0.0 (4)	C9—O2—C10—C11	−172.5 (3)
C2—C1—C6—C5	1.7 (4)	O2—C10—C11—C12	56.0 (4)
C2—C1—C6—C7	−177.4 (2)	C10—C11—C12—C13	−179.7 (3)
C4—C5—C6—C1	−1.2 (4)	C10—C11—C12—C14	55.3 (5)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O4—H4A···O3	0.82	2.28	2.721 (2)	114
O3—H3A···O1ⁱ	0.82	1.95	2.764 (2)	173
O4—H4A···O3ⁱⁱ	0.82	2.13	2.831 (2)	143

Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x+1, −y+2, −z+1.

Experimental details

Crystal data
Chemical formula	C₁₄H₁₈O₄
M_r	250.28
Crystal system, space group	Triclinic, P1
Temperature (K)	293
a, b, c (Å)	5.2790 (11), 10.244 (2), 13.834 (3)
α, β, γ (°)	69.05 (3), 80.11 (3), 78.79 (3)
V (Å³)	681.0 (2)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.09
Crystal size (mm)	0.30 × 0.20 × 0.10

Data collection
Diffractometer	Enraf–Nonius CAD-4 diffractometer
Absorption correction	ψ scan (North et al., 1968)
T_min, T_max	0.974, 0.991
No. of measured, independent and observed [I > 2σ(I)] reflections	2507, 2507, 1300
R_int	0.000
(sin θ/λ)_max (Å⁻¹)	0.603

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.059, 0.156, 1.00
No. of reflections	2507
No. of parameters	163
No. of restraints	2
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.14, −0.14

Computer programs: CAD-4 EXPRESS (Enraf–Nonius, 1994), XCAD4 (Harms & Wocadlo, 1995), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008), PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O4—H4A···O3	0.82	2.28	2.721 (2)	114
O3—H3A···O1ⁱ	0.82	1.95	2.764 (2)	173
O4—H4A···O3ⁱⁱ	0.82	2.13	2.831 (2)	143

Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x+1, −y+2, −z+1.

Acknowledgements

This work was sponsored by the earmarked fund for Natural Science Foundation of Jiangsu Province (grant No. BK2009213), Qing Lan Project of Jiangsu Province, Modern Agro-industry Technology Research System of China (grant No. CARS-22), Science and Technology Support Program of Jiangsu Province (grant No. BE2010419), Graduate Innovation Project of Jiangsu Province in 2011 (grant No. 284), and Start Research Project of Jiangsu University of Science and Technology (grant Nos. 35211002 and 33201002).

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