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Acta Crystallogr Sect E Struct Rep Online. 2010 April 1; 66(Pt 4): o942–o943.
Published online 2010 March 27. doi:  10.1107/S1600536810010809
PMCID: PMC2983789

(2E)-1-[2-Hydr­oxy-4-(2-methyl­prop­oxy)phen­yl]-3-(4-methyl­phen­yl)prop-2-en-1-one

Abstract

The benzene rings in the title compound, C20H22O3, form a dihedral angle of 10.39 (8)°. Overall, the mol­ecule is approximately planar with the exception of one of the terminal methyl groups; excluding this group, the r.m.s. deviation for the remaining 22 non-H atoms is 0.0968 Å. The conformation about the C=C bond is E, and an intra­molecular O—H(...)O hydrogen bond leads to the formation of an S(6) motif. In the crystal, linear supra­molecular chains are formed along the a axis via C—H(...)O contacts, and these are connected into double chains via C—H(...)π inter­actions.

Related literature

For the use of α,β-unsaturated ketones in organic synthesis, see: Marzinzik & Felder (1998 [triangle]); Srikanth et al. (2005 [triangle]); Nehad et al. (2007 [triangle]); Gaede & Mcdermott (1993 [triangle]); Shibata et al. (1993 [triangle]); Xu et al. (2001 [triangle]). For the biological activity of α,β-unsaturated ketones, see: Prasad et al. (2008 [triangle]); Zhao et al. (2007 [triangle]). Lambert et al. (2009 [triangle]); Jung et al. (2008 [triangle]); Reichwald et al. (2008 [triangle]); Boumendjel et al. (2008 [triangle]); Domínguez et al. (2005 [triangle]); Yun et al. (2006 [triangle]). For semi-empirical quantum chemical calculations, see: Stewart (2009 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-66-0o942-scheme1.jpg

Experimental

Crystal data

  • C20H22O3
  • M r = 310.38
  • Triclinic, An external file that holds a picture, illustration, etc.
Object name is e-66-0o942-efi1.jpg
  • a = 6.7795 (8) Å
  • b = 9.8830 (12) Å
  • c = 13.9064 (17) Å
  • α = 74.740 (2)°
  • β = 78.857 (2)°
  • γ = 74.103 (2)°
  • V = 857.12 (18) Å3
  • Z = 2
  • Mo Kα radiation
  • μ = 0.08 mm−1
  • T = 293 K
  • 0.30 × 0.20 × 0.20 mm

Data collection

  • Bruker SMART APEX CCD diffractometer
  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996 [triangle]) T min = 0.932, T max = 0.991
  • 9290 measured reflections
  • 3530 independent reflections
  • 2452 reflections with I > 2σ(I)
  • R int = 0.019

Refinement

  • R[F 2 > 2σ(F 2)] = 0.049
  • wR(F 2) = 0.142
  • S = 1.03
  • 3530 reflections
  • 212 parameters
  • H-atom parameters constrained
  • Δρmax = 0.16 e Å−3
  • Δρmin = −0.21 e Å−3

Data collection: APEX2 (Bruker, 2004 [triangle]); cell refinement: APEX2 and SAINT (Bruker, 2004 [triangle]); data reduction: SAINT and XPREP (Bruker, 2004 [triangle]); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: ORTEP-3 (Farrugia, 1997 [triangle]) and DIAMOND (Brandenburg, 2006 [triangle]); software used to prepare material for publication: publCIF (Westrip, 2010 [triangle]).

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810010809/pk2236sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810010809/pk2236Isup2.hkl

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

Acknowledgments

The authors are grateful to the Department of Science and Technology (DST) and the SAIF, II Madras, India, for the X-ray data collection.

supplementary crystallographic information

Comment

α,β-Unsaturated ketones (chalcones) are useful key intermediates in organic synthesis (Marzinzik & Felder, 1998; Srikanth et al., 2005). For example, they attract interest owing to their utility as starting materials in the synthesis of the five- (Nehad et al., 2007 & Gaede & Mcdermott, 1993), six- (Shibata et al., 1993), and seven-membered (Xu et al., 2001) heterocycles. Several analogues have been demonstrated to be active against both gram-positive and gram-negative bacterial strains, and also against fungal strains (Prasad et al., 2008; Zhao et al., 2007). Moreover, chalcones possess a wide spectrum of biological activities such as anti-oxidant, neuroprotective, anti-leishmanial, anti-mitotic, anti-malarial, anti-cancer, etc. (Lambert et al., 2009; Jung et al., 2008; Reichwald et al., 2008; Boumendjel et al., 2008; Domínguez et al., 200; Yun et al., 2006). In view of the importance of these compounds, the crystal structure of title compound, (I), was determined.

With the exception of the methyl-C19 atom, the molecular structure, Fig. 1, is essentially planar. Thus, the r.m.s. deviations of the 22 non-H atoms is 0.0968 Å [maximum deviation = 0.2173 (15) Å for the C6 atom] with the C19 atom lying 1.313 (4) Å out of this plane. The near planarity is manifested in the torsion angles with the maximum deviations from linearity (excluding that involving the C19 atom; O3–C17–C18–C19 = -58.7 (2) °) found in the C8–C9–C10–O1 and C8–C9–C10–C11 torsion angles of -6.2 (2) and 173.89 (14) °, respectively. The dihedral angle formed between the benzene rings is 10.39 (8) °. The conformation about the C8═C9 bond [1.325 (2) Å] is E. The presence of an intramolecular OH···Ocarbonyl hydrogen bond is noted, Table 1, which closes an S(6) motif.

In the crystal packing, both C–H···O and C–H···π interactions are observed. Linear supramolecular chains aligned along the a axis are mediated by C–H···O contacts, Fig. 2 and Table 1. Centrosymmetrically related pairs of these chains are connected into a double chain via C–H···π contacts formed between the methylene-C17—H and the ring centroid of the tolyl ring, Fig. 3 and Table 1.

Semi-empirical Quantum Chemical Calculations were performed on (I) using the MOPAC2009 program (Stewart, 2009) to optimize the structure with the Parameterization Model 6 (PM6) approximation together with the restricted Hartree-Fock closed-shell wavefunction. Minimizations were terminated at an r.m.s. gradient of less than 0.01 kJ mol-1 Å-1. The geometry optimised structure displays a significant difference in the relative orientation of the tolyl ring compared with the experimental structure. This is quantified by the value of the C6—C5—C8—C9 torsion angle of 150.7 compared with the experimental value of 179.72 (15) °. This change is related to the participation of this ring in the C–H···π contact as discussed above.

Experimental

A mixture of 2-hydroxy-4-isobutoxy acetophenone (0.01 mol) and 4-methyl benzaldehyde (0.01 mol) in ethanol (40 ml) were placed in a 250 ml round bottom flask and the resulting solution stirred at room temperature. After the solution became clear, a solution of potassium hydroxide (40%, 40 ml) was added slowly with constant stirring followed by stirring at room temperature for a further 20 h. After the completion of reaction, as indicated by TLC, the contents were poured onto crushed ice and acidified with dilute HCl (10%). The solid separated and was washed with water, filtered, and the crude product was crystallized from methanol to obtain (I) in 90 % yield; m.pt. 417 K. The yellow needles were obtained by the slow evaporation of a methanol solution of (I).

Refinement

The H atoms were placed geometrically (O–H = 0.83 Å and C–H = 0.93–0.98 Å) and refined as riding with Uiso(H) = 1.2–1.5Ueq(parent atom).

Figures

Fig. 1.
The molecular structure of (I) showing the atom-labelling scheme and displacement ellipsoids at the 50% probability level.
Fig. 2.
A supramolecular chain aligned along the a axis in (I), mediated by C–H···O interactions (orange dashed lines). Colour code: O, red; C, grey; and H, green.
Fig. 3.
A view in projection along the a axis of the unit cell contents in (I), showing C–H···π interactions (purple dashed lines) between the supramolecular chains illustrated in Fig. 2. Colour code: O, red; C, grey; and ...

Crystal data

C20H22O3Z = 2
Mr = 310.38F(000) = 332
Triclinic, P1Dx = 1.203 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 6.7795 (8) ÅCell parameters from 3222 reflections
b = 9.8830 (12) Åθ = 2.8–24.2°
c = 13.9064 (17) ŵ = 0.08 mm1
α = 74.740 (2)°T = 293 K
β = 78.857 (2)°Block, colourless
γ = 74.103 (2)°0.30 × 0.20 × 0.20 mm
V = 857.12 (18) Å3

Data collection

Bruker SMART APEX CCD diffractometer3530 independent reflections
Radiation source: fine-focus sealed tube2452 reflections with I > 2σ(I)
graphiteRint = 0.019
ω and [var phi] scansθmax = 26.5°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)h = −8→8
Tmin = 0.932, Tmax = 0.991k = −12→12
9290 measured reflectionsl = −17→17

Refinement

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) = 0.142H-atom parameters constrained
S = 1.03w = 1/[σ2(Fo2) + (0.067P)2 + 0.1242P] where P = (Fo2 + 2Fc2)/3
3530 reflections(Δ/σ)max = 0.001
212 parametersΔρmax = 0.16 e Å3
0 restraintsΔρmin = −0.21 e Å3

Special details

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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)

xyzUiso*/Ueq
O10.36395 (17)0.23227 (14)0.54491 (10)0.0693 (4)
O20.10785 (17)0.36469 (16)0.66378 (11)0.0787 (4)
H2o0.15060.31350.62280.118*
O30.34346 (17)0.64303 (13)0.82850 (9)0.0630 (3)
C11.4896 (3)−0.0477 (2)0.18171 (15)0.0735 (5)
H1A1.4928−0.14270.17530.110*
H1B1.6102−0.05060.20940.110*
H1C1.48740.01700.11670.110*
C21.2985 (2)0.00433 (18)0.25032 (12)0.0541 (4)
C31.2904 (2)0.10836 (18)0.30244 (13)0.0571 (4)
H31.40530.14630.29470.069*
C41.1166 (2)0.15668 (17)0.36524 (12)0.0531 (4)
H41.11640.22570.39970.064*
C50.9411 (2)0.10332 (16)0.37782 (11)0.0460 (4)
C60.9496 (2)−0.00067 (17)0.32580 (12)0.0529 (4)
H60.8345−0.03810.33290.063*
C71.1248 (3)−0.04960 (18)0.26386 (12)0.0565 (4)
H71.1264−0.12020.23060.068*
C80.7507 (2)0.15052 (17)0.44205 (11)0.0500 (4)
H80.64400.10720.44390.060*
C90.7096 (2)0.24698 (16)0.49809 (11)0.0487 (4)
H90.81160.29200.50080.058*
C100.5048 (2)0.28363 (17)0.55592 (12)0.0489 (4)
C110.4634 (2)0.37884 (16)0.62556 (11)0.0443 (4)
C120.6143 (2)0.43552 (16)0.64662 (12)0.0482 (4)
H120.74830.41350.61380.058*
C130.5715 (2)0.52170 (18)0.71343 (12)0.0527 (4)
H130.67520.55790.72550.063*
C140.3717 (2)0.55579 (16)0.76392 (11)0.0486 (4)
C150.2186 (2)0.50210 (17)0.74614 (12)0.0519 (4)
H150.08560.52440.77990.062*
C160.2630 (2)0.41471 (17)0.67776 (12)0.0500 (4)
C170.1455 (3)0.6734 (2)0.88789 (13)0.0624 (5)
H17A0.11090.58390.92650.075*
H17B0.04000.72420.84440.075*
C180.1529 (3)0.7644 (2)0.95744 (15)0.0725 (5)
H180.18760.85390.91620.087*
C190.3163 (5)0.6912 (4)1.0255 (2)0.1396 (12)
H19A0.28900.60101.06470.209*
H19B0.31490.75191.06940.209*
H19C0.44950.67380.98580.209*
C20−0.0607 (4)0.8042 (3)1.01622 (17)0.0974 (8)
H20A−0.15970.85420.97020.146*
H20B−0.05790.86561.05900.146*
H20C−0.09920.71811.05650.146*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
O10.0475 (7)0.0922 (9)0.0841 (9)−0.0267 (6)−0.0001 (6)−0.0423 (7)
O20.0374 (6)0.1094 (11)0.1091 (11)−0.0264 (7)0.0034 (6)−0.0578 (9)
O30.0544 (7)0.0737 (8)0.0670 (7)−0.0152 (6)0.0014 (6)−0.0326 (6)
C10.0640 (11)0.0825 (13)0.0680 (12)−0.0107 (10)0.0067 (9)−0.0247 (10)
C20.0514 (9)0.0575 (10)0.0483 (9)−0.0080 (7)−0.0034 (7)−0.0101 (8)
C30.0478 (9)0.0617 (10)0.0646 (10)−0.0188 (8)−0.0031 (8)−0.0156 (9)
C40.0525 (9)0.0551 (9)0.0568 (9)−0.0144 (7)−0.0067 (7)−0.0196 (8)
C50.0472 (8)0.0487 (8)0.0423 (8)−0.0109 (7)−0.0079 (6)−0.0091 (7)
C60.0521 (9)0.0585 (9)0.0540 (9)−0.0195 (8)−0.0066 (7)−0.0162 (8)
C70.0646 (10)0.0572 (10)0.0521 (9)−0.0135 (8)−0.0055 (8)−0.0219 (8)
C80.0453 (8)0.0576 (9)0.0493 (9)−0.0149 (7)−0.0076 (7)−0.0115 (8)
C90.0428 (8)0.0539 (9)0.0498 (9)−0.0121 (7)−0.0051 (7)−0.0121 (7)
C100.0419 (8)0.0538 (9)0.0511 (9)−0.0117 (7)−0.0081 (7)−0.0102 (7)
C110.0347 (7)0.0486 (8)0.0473 (8)−0.0080 (6)−0.0061 (6)−0.0082 (7)
C120.0323 (7)0.0557 (9)0.0553 (9)−0.0094 (6)−0.0020 (6)−0.0138 (7)
C130.0403 (8)0.0615 (10)0.0616 (10)−0.0154 (7)−0.0066 (7)−0.0193 (8)
C140.0466 (8)0.0492 (9)0.0471 (8)−0.0079 (7)−0.0043 (7)−0.0109 (7)
C150.0366 (8)0.0591 (10)0.0563 (9)−0.0092 (7)0.0022 (7)−0.0148 (8)
C160.0347 (8)0.0574 (9)0.0587 (9)−0.0123 (7)−0.0051 (7)−0.0136 (8)
C170.0605 (10)0.0658 (11)0.0568 (10)−0.0118 (9)0.0061 (8)−0.0198 (9)
C180.0815 (13)0.0665 (12)0.0679 (12)−0.0112 (10)0.0004 (10)−0.0262 (10)
C190.144 (3)0.168 (3)0.119 (2)0.027 (2)−0.0586 (19)−0.088 (2)
C200.1058 (18)0.0937 (16)0.0830 (15)−0.0119 (14)0.0221 (13)−0.0400 (13)

Geometric parameters (Å, °)

O1—C101.2474 (18)C9—H90.9300
O2—C161.3429 (18)C10—C111.460 (2)
O2—H2o0.8200C11—C121.401 (2)
O3—C141.3556 (19)C11—C161.410 (2)
O3—C171.4332 (19)C12—C131.360 (2)
C1—C21.506 (2)C12—H120.9300
C1—H1A0.9600C13—C141.396 (2)
C1—H1B0.9600C13—H130.9300
C1—H1C0.9600C14—C151.374 (2)
C2—C71.383 (2)C15—C161.386 (2)
C2—C31.390 (2)C15—H150.9300
C3—C41.376 (2)C17—C181.499 (3)
C3—H30.9300C17—H17A0.9700
C4—C51.393 (2)C17—H17B0.9700
C4—H40.9300C18—C191.500 (3)
C5—C61.388 (2)C18—C201.523 (3)
C5—C81.458 (2)C18—H180.9800
C6—C71.377 (2)C19—H19A0.9600
C6—H60.9300C19—H19B0.9600
C7—H70.9300C19—H19C0.9600
C8—C91.325 (2)C20—H20A0.9600
C8—H80.9300C20—H20B0.9600
C9—C101.467 (2)C20—H20C0.9600
C16—O2—H2o109.5C13—C12—H12118.9
C14—O3—C17118.25 (13)C11—C12—H12118.9
C2—C1—H1A109.5C12—C13—C14119.92 (14)
C2—C1—H1B109.5C12—C13—H13120.0
H1A—C1—H1B109.5C14—C13—H13120.0
C2—C1—H1C109.5O3—C14—C15124.34 (14)
H1A—C1—H1C109.5O3—C14—C13115.70 (14)
H1B—C1—H1C109.5C15—C14—C13119.96 (14)
C7—C2—C3117.53 (15)C14—C15—C16119.85 (14)
C7—C2—C1121.29 (16)C14—C15—H15120.1
C3—C2—C1121.18 (16)C16—C15—H15120.1
C4—C3—C2121.64 (15)O2—C16—C15117.28 (13)
C4—C3—H3119.2O2—C16—C11121.36 (14)
C2—C3—H3119.2C15—C16—C11121.35 (14)
C3—C4—C5120.67 (15)O3—C17—C18109.14 (15)
C3—C4—H4119.7O3—C17—H17A109.9
C5—C4—H4119.7C18—C17—H17A109.9
C6—C5—C4117.58 (14)O3—C17—H17B109.9
C6—C5—C8118.64 (14)C18—C17—H17B109.9
C4—C5—C8123.78 (14)H17A—C17—H17B108.3
C7—C6—C5121.43 (15)C17—C18—C19111.91 (17)
C7—C6—H6119.3C17—C18—C20109.22 (18)
C5—C6—H6119.3C19—C18—C20112.0 (2)
C6—C7—C2121.14 (15)C17—C18—H18107.8
C6—C7—H7119.4C19—C18—H18107.8
C2—C7—H7119.4C20—C18—H18107.8
C9—C8—C5128.63 (15)C18—C19—H19A109.5
C9—C8—H8115.7C18—C19—H19B109.5
C5—C8—H8115.7H19A—C19—H19B109.5
C8—C9—C10120.73 (14)C18—C19—H19C109.5
C8—C9—H9119.6H19A—C19—H19C109.5
C10—C9—H9119.6H19B—C19—H19C109.5
O1—C10—C11119.71 (14)C18—C20—H20A109.5
O1—C10—C9119.01 (14)C18—C20—H20B109.5
C11—C10—C9121.27 (13)H20A—C20—H20B109.5
C12—C11—C16116.67 (14)C18—C20—H20C109.5
C12—C11—C10123.71 (13)H20A—C20—H20C109.5
C16—C11—C10119.59 (13)H20B—C20—H20C109.5
C13—C12—C11122.25 (14)
C7—C2—C3—C4−0.1 (3)C16—C11—C12—C13−0.4 (2)
C1—C2—C3—C4179.96 (15)C10—C11—C12—C13−178.68 (14)
C2—C3—C4—C5−0.7 (3)C11—C12—C13—C140.3 (2)
C3—C4—C5—C60.7 (2)C17—O3—C14—C154.8 (2)
C3—C4—C5—C8−179.25 (14)C17—O3—C14—C13−175.59 (14)
C4—C5—C6—C70.0 (2)C12—C13—C14—O3−179.59 (13)
C8—C5—C6—C7179.92 (14)C12—C13—C14—C150.1 (2)
C5—C6—C7—C2−0.7 (2)O3—C14—C15—C16179.37 (14)
C3—C2—C7—C60.7 (2)C13—C14—C15—C16−0.3 (2)
C1—C2—C7—C6−179.29 (15)C14—C15—C16—O2179.65 (15)
C6—C5—C8—C9179.72 (15)C14—C15—C16—C110.1 (2)
C4—C5—C8—C9−0.3 (3)C12—C11—C16—O2−179.30 (15)
C5—C8—C9—C10178.15 (14)C10—C11—C16—O2−0.9 (2)
C8—C9—C10—O1−6.2 (2)C12—C11—C16—C150.2 (2)
C8—C9—C10—C11173.89 (14)C10—C11—C16—C15178.55 (14)
O1—C10—C11—C12176.62 (15)C14—O3—C17—C18176.86 (14)
C9—C10—C11—C12−3.5 (2)O3—C17—C18—C19−58.7 (2)
O1—C10—C11—C16−1.6 (2)O3—C17—C18—C20176.68 (15)
C9—C10—C11—C16178.27 (13)

Hydrogen-bond geometry (Å, °)

Cg is the centroid of the C2–C7 ring.
D—H···AD—HH···AD···AD—H···A
O2—H2o···O10.821.772.499 (2)148
C12—H12···O2i0.932.553.268 (2)135
C17—H17b···Cgii0.972.823.705 (2)153

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

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: PK2236).

References

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