trans-1,2-Bis(3,5-dimethoxy-phen-yl)ethene.

The title compound, C(18)H(20)O(4), was prepared in high yield from 3,5-dimethoxy-styrene via a Ru-catalysed homo-olefin metathesis. Exclusive formation of the E-configurated isomer was observed. Inter-estingly, one symmetric unit contains two mol-ecules adopting an s-syn-anti and and an all-s-anti conformation.

Related literature

For the preparation of differently substituted stilbenes using a Ru-catalysed metathesis strategy, see: Velder et al. (2006 ▶). Alternative methodologies for the synthesis of ­oxy-function­alized stilbenes using Wittig-type olefinations or Heck couplings have been described by Kim et al. (2002 ▶), Lion et al. (2005 ▶), Botella & Nayera (2004 ▶) and Reetz et al. (1998 ▶). For the bioactivity of various stilbenes with a focus on their anti­cancer activity, see: Aggarwal et al. (2004 ▶); Wolter & Stein (2002 ▶); Fremont (2000 ▶); Jang et al. (1997 ▶); Wieder et al. (2001 ▶). For related structures and syntheses see: Yin et al. (2002 ▶); Uda et al. (2002 ▶).

Experimental

Crystal data

C18H20O4

M = 300.34

Monoclinic,

a = 7.1954 (3) Å

b = 9.4203 (4) Å

c = 22.6762 (5) Å

β = 93.783 (2)°

V = 1533.71 (10) Å3

Z = 4

Mo Kα radiation

μ = 0.09 mm−1

T = 100 K

0.4 × 0.2 × 0.2 mm

Data collection

Nonius KappaCCD diffractometer

Absorption correction: none

7687 measured reflections

3320 independent reflections

2142 reflections with I > 2σ(I)

R int = 0.041

Refinement

R[F 2 > 2σ(F 2)] = 0.055

wR(F 2) = 0.150

S = 1.03

3320 reflections

207 parameters

H-atom parameters constrained

Δρmax = 0.24 e Å−3

Δρmin = −0.24 e Å−3

Data collection: COLLECT (Hooft, 1998 ▶); cell refinement: DENZO (Otwinowski & Minor, 1997 ▶); data reduction: DENZO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SCHAKAL99 (Keller 1999 ▶); software used to prepare material for publication: PLATON (Spek, 2009 ▶) and enCIFer (Allen et al., 2004 ▶).

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053680903116X/hg2547sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S160053680903116X/hg2547Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C18H20O4	F(000) = 640
Mr = 300.34	Dx = 1.301 Mg m−3
Monoclinic, P21/c	Melting point: 142 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 7.1954 (3) Å	Cell parameters from 7687 reflections
b = 9.4203 (4) Å	θ = 2.3–27.0°
c = 22.6762 (5) Å	µ = 0.09 mm−1
β = 93.783 (2)°	T = 100 K
V = 1533.71 (10) Å3	Needle, colourless
Z = 4	0.4 × 0.2 × 0.2 mm

Nonius KappaCCD diffractometer	2142 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.041
graphite	θmax = 27.0°, θmin = 2.3°
φ and ω scans	h = −6→9
7687 measured reflections	k = −12→10
3320 independent reflections	l = −25→28

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)] = 0.055	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.150	H-atom parameters constrained
S = 1.03	w = 1/[σ2(Fo2) + (0.0722P)2 + 0.274P] where P = (Fo2 + 2Fc2)/3
3320 reflections	(Δ/σ)max < 0.001
207 parameters	Δρmax = 0.24 e Å−3
0 restraints	Δρmin = −0.24 e Å−3

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. The coordinates of the hydrogenatoms are constrained, and the U values of the H atoms are constrained relative to the Ueq of the atom the hydrogen binds to (1.2 for CH and CH2, 1.5 for CH3).

	x	y	z	Uiso*/Ueq
O1	0.16550 (18)	0.11969 (13)	0.29039 (5)	0.0322 (4)
O2	0.11990 (18)	0.52539 (13)	0.41414 (6)	0.0346 (4)
C1	0.0096 (2)	0.07001 (18)	0.49846 (8)	0.0272 (4)
H1	−0.0099	0.1220	0.5334	0.033*
C2	0.0575 (2)	0.15286 (19)	0.44674 (8)	0.0256 (4)
C3	0.0903 (2)	0.0879 (2)	0.39261 (8)	0.0268 (4)
H3	0.0831	−0.0123	0.3885	0.032*
C4	0.1329 (2)	0.17169 (19)	0.34549 (8)	0.0259 (4)
C5	0.1450 (2)	0.31913 (19)	0.35017 (8)	0.0275 (4)
H5	0.1748	0.3753	0.3173	0.033*
C6	0.1123 (2)	0.38210 (19)	0.40394 (8)	0.0267 (4)
C7	0.0691 (2)	0.2989 (2)	0.45200 (8)	0.0274 (4)
H7	0.0475	0.3428	0.4886	0.033*
C8	0.1666 (3)	−0.03060 (19)	0.28252 (8)	0.0312 (5)
H8A	0.2575	−0.0734	0.3113	0.047*
H8B	0.2006	−0.0530	0.2424	0.047*
H8C	0.0424	−0.0687	0.2884	0.047*
C9	0.1455 (3)	0.6156 (2)	0.36467 (9)	0.0359 (5)
H9A	0.2645	0.5933	0.3482	0.054*
H9B	0.1457	0.7149	0.3775	0.054*
H9C	0.0437	0.6003	0.3344	0.054*
O3	0.31579 (18)	0.49045 (14)	0.21349 (5)	0.0360 (4)
O4	0.33384 (18)	0.03486 (14)	0.13362 (6)	0.0392 (4)
C10	0.4952 (2)	0.43244 (19)	0.00794 (8)	0.0299 (4)
H10	0.5284	0.3637	−0.0202	0.040 (6)*
C11	0.4382 (2)	0.3787 (2)	0.06489 (8)	0.0273 (4)
C12	0.4051 (2)	0.4693 (2)	0.11208 (8)	0.0289 (4)
H12	0.4206	0.5689	0.1083	0.020 (5)*
C13	0.3493 (2)	0.4114 (2)	0.16439 (8)	0.0288 (5)
C14	0.3246 (2)	0.2665 (2)	0.17034 (8)	0.0303 (5)
H14	0.2849	0.2285	0.2062	0.047 (6)*
C15	0.3581 (2)	0.1774 (2)	0.12378 (8)	0.0296 (5)
C16	0.4155 (2)	0.2328 (2)	0.07095 (8)	0.0293 (5)
H16	0.4391	0.1711	0.0392	0.030 (5)*
C17	0.3394 (3)	0.6410 (2)	0.20992 (9)	0.0373 (5)
H17A	0.4679	0.6625	0.2011	0.056*
H17B	0.3128	0.6845	0.2477	0.056*
H17C	0.2536	0.6792	0.1785	0.056*
C18	0.3671 (3)	−0.0593 (2)	0.08589 (9)	0.0386 (5)
H18A	0.2853	−0.0340	0.0512	0.058*
H18B	0.3415	−0.1571	0.0976	0.058*
H18C	0.4974	−0.0514	0.0761	0.058*

	U11	U22	U33	U12	U13	U23
O1	0.0478 (8)	0.0283 (7)	0.0216 (7)	−0.0022 (6)	0.0118 (6)	0.0006 (6)
O2	0.0487 (8)	0.0268 (8)	0.0291 (8)	−0.0033 (6)	0.0080 (6)	0.0032 (6)
C1	0.0288 (9)	0.0332 (10)	0.0200 (9)	0.0004 (8)	0.0046 (7)	−0.0001 (8)
C2	0.0249 (9)	0.0291 (11)	0.0227 (10)	0.0000 (8)	0.0014 (7)	0.0040 (8)
C3	0.0280 (10)	0.0261 (10)	0.0265 (11)	−0.0010 (7)	0.0028 (8)	0.0025 (8)
C4	0.0256 (9)	0.0307 (11)	0.0216 (10)	0.0010 (8)	0.0034 (7)	0.0005 (8)
C5	0.0291 (10)	0.0288 (11)	0.0252 (10)	−0.0006 (8)	0.0053 (8)	0.0073 (8)
C6	0.0269 (10)	0.0249 (10)	0.0281 (11)	−0.0020 (8)	0.0008 (8)	0.0025 (8)
C7	0.0294 (10)	0.0295 (10)	0.0235 (10)	−0.0007 (8)	0.0040 (8)	0.0012 (8)
C8	0.0372 (11)	0.0303 (11)	0.0266 (11)	−0.0027 (8)	0.0056 (8)	−0.0018 (8)
C9	0.0444 (12)	0.0292 (11)	0.0342 (12)	−0.0031 (9)	0.0046 (9)	0.0078 (9)
O3	0.0443 (8)	0.0397 (8)	0.0251 (8)	−0.0033 (6)	0.0097 (6)	0.0002 (6)
O4	0.0489 (9)	0.0328 (8)	0.0370 (8)	−0.0008 (6)	0.0108 (7)	0.0093 (6)
C10	0.0324 (10)	0.0344 (10)	0.0232 (10)	−0.0013 (9)	0.0044 (8)	0.0020 (9)
C11	0.0248 (9)	0.0339 (11)	0.0234 (10)	−0.0013 (8)	0.0019 (7)	0.0060 (8)
C12	0.0285 (10)	0.0308 (11)	0.0275 (11)	−0.0019 (8)	0.0020 (8)	0.0048 (8)
C13	0.0252 (10)	0.0396 (12)	0.0218 (10)	−0.0017 (8)	0.0027 (7)	0.0028 (8)
C14	0.0294 (10)	0.0383 (12)	0.0237 (10)	−0.0005 (8)	0.0051 (8)	0.0093 (9)
C15	0.0266 (10)	0.0320 (11)	0.0304 (11)	−0.0018 (8)	0.0023 (8)	0.0090 (9)
C16	0.0282 (10)	0.0339 (12)	0.0259 (11)	−0.0001 (8)	0.0025 (8)	0.0018 (8)
C17	0.0434 (12)	0.0404 (12)	0.0287 (12)	−0.0045 (10)	0.0078 (9)	−0.0043 (9)
C18	0.0412 (12)	0.0330 (12)	0.0423 (13)	−0.0009 (9)	0.0070 (10)	0.0054 (10)

O1—C4	1.376 (2)	O3—C13	1.374 (2)
O1—C8	1.427 (2)	O3—C17	1.432 (2)
O2—C6	1.370 (2)	O4—C15	1.375 (2)
O2—C9	1.429 (2)	O4—C18	1.432 (2)
C1—C1i	1.328 (3)	C10—C10ii	1.326 (4)
C1—C2	1.469 (2)	C10—C11	1.470 (2)
C1—H1	0.9500	C10—H10	0.9500
C2—C7	1.383 (3)	C11—C16	1.392 (3)
C2—C3	1.405 (2)	C11—C12	1.401 (3)
C3—C4	1.379 (2)	C12—C13	1.389 (2)
C3—H3	0.9500	C12—H12	0.9500
C4—C5	1.395 (3)	C13—C14	1.384 (3)
C5—C6	1.390 (2)	C14—C15	1.382 (3)
C5—H5	0.9500	C14—H14	0.9500
C6—C7	1.394 (2)	C15—C16	1.394 (2)
C7—H7	0.9500	C16—H16	0.9500
C8—H8A	0.9800	C17—H17A	0.9800
C8—H8B	0.9800	C17—H17B	0.9800
C8—H8C	0.9800	C17—H17C	0.9800
C9—H9A	0.9800	C18—H18A	0.9800
C9—H9B	0.9800	C18—H18B	0.9800
C9—H9C	0.9800	C18—H18C	0.9800
C4—O1—C8	117.99 (13)	C13—O3—C17	117.61 (14)
C6—O2—C9	117.31 (15)	C15—O4—C18	116.97 (14)
C1i—C1—C2	126.9 (2)	C10ii—C10—C11	126.3 (2)
C1i—C1—H1	116.6	C10ii—C10—H10	116.9
C2—C1—H1	116.6	C11—C10—H10	116.9
C7—C2—C3	119.73 (16)	C16—C11—C12	119.91 (16)
C7—C2—C1	118.41 (16)	C16—C11—C10	117.89 (17)
C3—C2—C1	121.87 (16)	C12—C11—C10	122.19 (17)
C4—C3—C2	119.10 (17)	C13—C12—C11	119.14 (17)
C4—C3—H3	120.5	C13—C12—H12	120.4
C2—C3—H3	120.5	C11—C12—H12	120.4
O1—C4—C3	124.02 (16)	O3—C13—C14	115.15 (16)
O1—C4—C5	114.20 (15)	O3—C13—C12	123.76 (17)
C3—C4—C5	121.77 (16)	C14—C13—C12	121.09 (17)
C6—C5—C4	118.58 (16)	C15—C14—C13	119.63 (16)
C6—C5—H5	120.7	C15—C14—H14	120.2
C4—C5—H5	120.7	C13—C14—H14	120.2
O2—C6—C5	124.17 (16)	O4—C15—C14	116.03 (16)
O2—C6—C7	115.49 (16)	O4—C15—C16	123.58 (17)
C5—C6—C7	120.34 (17)	C14—C15—C16	120.38 (17)
C2—C7—C6	120.47 (17)	C11—C16—C15	119.84 (17)
C2—C7—H7	119.8	C11—C16—H16	120.1
C6—C7—H7	119.8	C15—C16—H16	120.1
O1—C8—H8A	109.5	O3—C17—H17A	109.5
O1—C8—H8B	109.5	O3—C17—H17B	109.5
H8A—C8—H8B	109.5	H17A—C17—H17B	109.5
O1—C8—H8C	109.5	O3—C17—H17C	109.5
H8A—C8—H8C	109.5	H17A—C17—H17C	109.5
H8B—C8—H8C	109.5	H17B—C17—H17C	109.5
O2—C9—H9A	109.5	O4—C18—H18A	109.5
O2—C9—H9B	109.5	O4—C18—H18B	109.5
H9A—C9—H9B	109.5	H18A—C18—H18B	109.5
O2—C9—H9C	109.5	O4—C18—H18C	109.5
H9A—C9—H9C	109.5	H18A—C18—H18C	109.5
H9B—C9—H9C	109.5	H18B—C18—H18C	109.5
C1i—C1—C2—C7	179.3 (2)	C10ii—C10—C11—C16	172.5 (2)
C1i—C1—C2—C3	−0.3 (3)	C10ii—C10—C11—C12	−6.9 (4)
C7—C2—C3—C4	−0.2 (3)	C16—C11—C12—C13	−0.2 (3)
C1—C2—C3—C4	179.35 (16)	C10—C11—C12—C13	179.18 (17)
C8—O1—C4—C3	−4.1 (2)	C17—O3—C13—C14	179.90 (16)
C8—O1—C4—C5	176.49 (15)	C17—O3—C13—C12	0.3 (3)
C2—C3—C4—O1	−179.24 (16)	C11—C12—C13—O3	179.04 (16)
C2—C3—C4—C5	0.2 (3)	C11—C12—C13—C14	−0.5 (3)
O1—C4—C5—C6	179.31 (15)	O3—C13—C14—C15	−178.83 (15)
C3—C4—C5—C6	−0.2 (3)	C12—C13—C14—C15	0.8 (3)
C9—O2—C6—C5	6.2 (3)	C18—O4—C15—C14	179.78 (16)
C9—O2—C6—C7	−173.96 (15)	C18—O4—C15—C16	−1.1 (3)
C4—C5—C6—O2	179.99 (16)	C13—C14—C15—O4	178.80 (16)
C4—C5—C6—C7	0.2 (3)	C13—C14—C15—C16	−0.3 (3)
C3—C2—C7—C6	0.2 (3)	C12—C11—C16—C15	0.6 (3)
C1—C2—C7—C6	−179.33 (16)	C10—C11—C16—C15	−178.75 (16)
O2—C6—C7—C2	179.95 (15)	O4—C15—C16—C11	−179.43 (16)
C5—C6—C7—C2	−0.2 (3)	C14—C15—C16—C11	−0.4 (3)