Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536803017938/wn6179sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536803017938/wn6179Isup2.hkl |
CCDC reference: 222870
The title dihydrofuran was obtained by the reaction of acetylacetone (100 mg, 0.001 mol) with 2,2'-sulfonylbis(1,3-diphenylprop-2-en-1-one) (478 mg, 0.001 mol) in the presence of sodium ethoxide (0.002 mol) in dimethylformamide (10 ml). Colourless single crystals of the compound were obtained as transparent plates from its saturated solution in methanol, by slow evaporation at room temperature.
The H atoms were placed in calculated positions and were allowed to ride on their respective carrier atoms. The C—H lengths are 0.98 Å for methyl H atoms, 1.00 Å for other Csp3—H and 0.95 Å for Csp2—H. For methyl H atoms, Uiso values were set equvalues were was set equal to 1.2Ueq of the carrier atom.
Data collection: SMART (Bruker, 1999); cell refinement: SMART; data reduction: SAINT (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 1999); software used to prepare material for publication: SHELXL97.
Fig. 1. The molecular structure of (I), with the atom-numbering scheme and 50% probability displacement ellipsoids. | |
Fig. 2. Packing of the molecules of (I), viewed down the b axis. |
C20H18O3 | F(000) = 648 |
Mr = 306.34 | Dx = 1.301 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 1024 reflections |
a = 9.846 (2) Å | θ = 2.2–26.3° |
b = 10.564 (2) Å | µ = 0.09 mm−1 |
c = 16.340 (3) Å | T = 150 K |
β = 113.023 (2)° | Plate, colourless |
V = 1564.2 (5) Å3 | 0.28 × 0.22 × 0.10 mm |
Z = 4 |
Bruker SMART CCD diffractometer | 4750 independent reflections |
Radiation source: fine-focus sealed tube | 3623 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.036 |
Detector resolution: 8 pixels mm-1 | θmax = 30.5°, θmin = 2.3° |
ω scans | h = −14→14 |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | k = −15→15 |
Tmin = 0.95, Tmax = 0.99 | l = −22→22 |
21162 measured reflections |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.051 | H-atom parameters constrained |
wR(F2) = 0.149 | w = 1/[σ2(Fo2) + (0.0745P)2 + 0.5171P] where P = (Fo2 + 2Fc2)/3 |
S = 1.08 | (Δ/σ)max < 0.001 |
4750 reflections | Δρmax = 0.45 e Å−3 |
209 parameters | Δρmin = −0.42 e Å−3 |
0 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0025 (19) |
C20H18O3 | V = 1564.2 (5) Å3 |
Mr = 306.34 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 9.846 (2) Å | µ = 0.09 mm−1 |
b = 10.564 (2) Å | T = 150 K |
c = 16.340 (3) Å | 0.28 × 0.22 × 0.10 mm |
β = 113.023 (2)° |
Bruker SMART CCD diffractometer | 4750 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | 3623 reflections with I > 2σ(I) |
Tmin = 0.95, Tmax = 0.99 | Rint = 0.036 |
21162 measured reflections |
R[F2 > 2σ(F2)] = 0.051 | 0 restraints |
wR(F2) = 0.149 | H-atom parameters constrained |
S = 1.08 | Δρmax = 0.45 e Å−3 |
4750 reflections | Δρmin = −0.42 e Å−3 |
209 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
O1 | 0.29836 (11) | −0.02468 (10) | 0.21634 (6) | 0.0317 (2) | |
O2 | 0.03830 (12) | 0.18776 (11) | −0.01268 (7) | 0.0351 (3) | |
O3 | 0.47589 (11) | 0.15842 (12) | 0.31227 (7) | 0.0349 (3) | |
C1 | 0.13260 (13) | 0.12574 (12) | 0.13887 (8) | 0.0221 (2) | |
C2 | 0.23062 (14) | 0.03699 (13) | 0.13768 (8) | 0.0257 (3) | |
C3 | 0.25767 (14) | 0.03759 (13) | 0.28226 (8) | 0.0236 (3) | |
H3 | 0.2278 | −0.0258 | 0.3175 | 0.028* | |
C4 | 0.12611 (13) | 0.12888 (12) | 0.23049 (8) | 0.0206 (2) | |
H4 | 0.1506 | 0.2161 | 0.2557 | 0.025* | |
C5 | 0.04548 (14) | 0.20582 (13) | 0.06339 (8) | 0.0250 (3) | |
C6 | −0.03817 (17) | 0.31478 (15) | 0.08198 (10) | 0.0330 (3) | |
H6A | −0.0920 | 0.3609 | 0.0267 | 0.049* | |
H6B | 0.0315 | 0.3721 | 0.1254 | 0.049* | |
H6C | −0.1082 | 0.2819 | 0.1059 | 0.049* | |
C7 | 0.27967 (17) | −0.00506 (17) | 0.06673 (10) | 0.0364 (3) | |
H7A | 0.3530 | −0.0726 | 0.0898 | 0.055* | |
H7B | 0.3237 | 0.0666 | 0.0478 | 0.055* | |
H7C | 0.1946 | −0.0368 | 0.0158 | 0.055* | |
C8 | 0.39049 (14) | 0.11480 (13) | 0.34269 (8) | 0.0232 (2) | |
C9 | 0.40904 (13) | 0.14052 (12) | 0.43631 (8) | 0.0216 (2) | |
C10 | 0.53402 (15) | 0.20871 (13) | 0.49053 (9) | 0.0290 (3) | |
H10 | 0.6026 | 0.2379 | 0.4670 | 0.035* | |
C11 | 0.55789 (18) | 0.23374 (15) | 0.57856 (10) | 0.0365 (3) | |
H11 | 0.6426 | 0.2803 | 0.6149 | 0.044* | |
C12 | 0.45867 (19) | 0.19110 (16) | 0.61367 (10) | 0.0376 (4) | |
H12 | 0.4755 | 0.2083 | 0.6739 | 0.045* | |
C13 | 0.33505 (18) | 0.12346 (16) | 0.56067 (10) | 0.0348 (3) | |
H13 | 0.2673 | 0.0941 | 0.5848 | 0.042* | |
C14 | 0.30931 (15) | 0.09814 (14) | 0.47198 (9) | 0.0270 (3) | |
H14 | 0.2240 | 0.0521 | 0.4359 | 0.032* | |
C15 | −0.02040 (14) | 0.08794 (12) | 0.23294 (8) | 0.0214 (2) | |
C16 | −0.07281 (15) | 0.14645 (13) | 0.29180 (8) | 0.0258 (3) | |
H16 | −0.0163 | 0.2116 | 0.3301 | 0.031* | |
C17 | −0.20727 (16) | 0.11008 (15) | 0.29483 (9) | 0.0299 (3) | |
H17 | −0.2412 | 0.1500 | 0.3354 | 0.036* | |
C18 | −0.29162 (15) | 0.01543 (15) | 0.23839 (9) | 0.0302 (3) | |
H18 | −0.3834 | −0.0090 | 0.2400 | 0.036* | |
C19 | −0.24020 (15) | −0.04308 (13) | 0.17952 (9) | 0.0278 (3) | |
H19 | −0.2975 | −0.1076 | 0.1409 | 0.033* | |
C20 | −0.10536 (14) | −0.00780 (12) | 0.17667 (8) | 0.0240 (3) | |
H20 | −0.0712 | −0.0487 | 0.1365 | 0.029* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0330 (5) | 0.0351 (5) | 0.0232 (5) | 0.0121 (4) | 0.0068 (4) | −0.0028 (4) |
O2 | 0.0395 (6) | 0.0430 (6) | 0.0216 (5) | −0.0019 (5) | 0.0107 (4) | 0.0022 (4) |
O3 | 0.0260 (5) | 0.0526 (7) | 0.0284 (5) | −0.0046 (4) | 0.0133 (4) | 0.0038 (4) |
C1 | 0.0208 (5) | 0.0263 (6) | 0.0188 (5) | −0.0013 (4) | 0.0073 (4) | −0.0009 (4) |
C2 | 0.0231 (6) | 0.0311 (6) | 0.0206 (6) | 0.0006 (5) | 0.0059 (4) | −0.0048 (5) |
C3 | 0.0229 (6) | 0.0266 (6) | 0.0197 (5) | 0.0022 (5) | 0.0065 (4) | −0.0006 (4) |
C4 | 0.0202 (5) | 0.0230 (6) | 0.0178 (5) | 0.0007 (4) | 0.0066 (4) | −0.0012 (4) |
C5 | 0.0216 (6) | 0.0287 (6) | 0.0229 (6) | −0.0032 (5) | 0.0068 (4) | 0.0014 (5) |
C6 | 0.0310 (7) | 0.0349 (7) | 0.0305 (7) | 0.0084 (6) | 0.0092 (5) | 0.0066 (6) |
C7 | 0.0292 (7) | 0.0504 (9) | 0.0292 (7) | 0.0037 (6) | 0.0111 (6) | −0.0138 (6) |
C8 | 0.0194 (5) | 0.0286 (6) | 0.0206 (5) | 0.0029 (4) | 0.0067 (4) | 0.0028 (4) |
C9 | 0.0204 (5) | 0.0235 (6) | 0.0198 (5) | 0.0036 (4) | 0.0066 (4) | 0.0027 (4) |
C10 | 0.0261 (6) | 0.0293 (7) | 0.0283 (6) | −0.0012 (5) | 0.0068 (5) | −0.0018 (5) |
C11 | 0.0366 (8) | 0.0342 (7) | 0.0292 (7) | 0.0037 (6) | 0.0027 (6) | −0.0074 (6) |
C12 | 0.0466 (9) | 0.0397 (8) | 0.0225 (6) | 0.0165 (7) | 0.0094 (6) | −0.0020 (6) |
C13 | 0.0397 (8) | 0.0436 (8) | 0.0257 (7) | 0.0126 (6) | 0.0178 (6) | 0.0076 (6) |
C14 | 0.0253 (6) | 0.0328 (7) | 0.0241 (6) | 0.0019 (5) | 0.0108 (5) | 0.0037 (5) |
C15 | 0.0215 (5) | 0.0233 (6) | 0.0186 (5) | 0.0010 (4) | 0.0071 (4) | 0.0005 (4) |
C16 | 0.0264 (6) | 0.0297 (6) | 0.0217 (6) | 0.0008 (5) | 0.0098 (5) | −0.0031 (5) |
C17 | 0.0281 (7) | 0.0395 (8) | 0.0254 (6) | 0.0042 (5) | 0.0141 (5) | 0.0014 (5) |
C18 | 0.0224 (6) | 0.0392 (7) | 0.0286 (6) | −0.0003 (5) | 0.0097 (5) | 0.0079 (5) |
C19 | 0.0270 (6) | 0.0268 (6) | 0.0256 (6) | −0.0040 (5) | 0.0059 (5) | 0.0028 (5) |
C20 | 0.0254 (6) | 0.0244 (6) | 0.0209 (5) | −0.0004 (5) | 0.0077 (5) | −0.0005 (4) |
O1—C2 | 1.360 (2) | C9—C10 | 1.4019 (18) |
O1—C3 | 1.446 (2) | C10—C11 | 1.389 (2) |
O2—C5 | 1.232 (2) | C10—H10 | 0.9500 |
O3—C8 | 1.222 (2) | C11—C12 | 1.387 (3) |
C1—C2 | 1.351 (2) | C11—H11 | 0.9500 |
C1—C5 | 1.465 (2) | C12—C13 | 1.385 (2) |
C1—C4 | 1.524 (2) | C12—H12 | 0.9500 |
C2—C7 | 1.487 (2) | C13—C14 | 1.3960 (19) |
C3—C8 | 1.530 (2) | C13—H13 | 0.9500 |
C3—C4 | 1.571 (2) | C14—H14 | 0.9500 |
C3—H3 | 1.0000 | C15—C16 | 1.4005 (17) |
C4—C15 | 1.5214 (17) | C15—C20 | 1.4023 (17) |
C4—H4 | 1.0000 | C16—C17 | 1.3978 (19) |
C5—C6 | 1.514 (2) | C16—H16 | 0.9500 |
C6—H6A | 0.9800 | C17—C18 | 1.393 (2) |
C6—H6B | 0.9800 | C17—H17 | 0.9500 |
C6—H6C | 0.9800 | C18—C19 | 1.394 (2) |
C7—H7A | 0.9800 | C18—H18 | 0.9500 |
C7—H7B | 0.9800 | C19—C20 | 1.3971 (19) |
C7—H7C | 0.9800 | C19—H19 | 0.9500 |
C8—C9 | 1.4929 (17) | C20—H20 | 0.9500 |
C9—C14 | 1.3971 (18) | ||
C2—O1—C3 | 108.0 (1) | C14—C9—C10 | 119.18 (12) |
C2—C1—C5 | 125.1 (1) | C14—C9—C8 | 123.01 (12) |
C2—C1—C4 | 109.5 (1) | C10—C9—C8 | 117.80 (12) |
C5—C1—C4 | 125.4 (1) | C11—C10—C9 | 120.22 (14) |
C1—C2—O1 | 114.1 (1) | C11—C10—H10 | 119.9 |
C1—C2—C7 | 132.1 (1) | C9—C10—H10 | 119.9 |
O1—C2—C7 | 113.9 (1) | C12—C11—C10 | 120.33 (14) |
O1—C3—C8 | 107.9 (1) | C12—C11—H11 | 119.8 |
O1—C3—C4 | 106.8 (1) | C10—C11—H11 | 119.8 |
C8—C3—C4 | 109.7 (1) | C13—C12—C11 | 119.86 (13) |
O1—C3—H3 | 110.8 | C13—C12—H12 | 120.1 |
C8—C3—H3 | 110.8 | C11—C12—H12 | 120.1 |
C4—C3—H3 | 110.8 | C12—C13—C14 | 120.42 (14) |
C15—C4—C1 | 115.10 (10) | C12—C13—H13 | 119.8 |
C15—C4—C3 | 113.7 (1) | C14—C13—H13 | 119.8 |
C1—C4—C3 | 99.97 (9) | C13—C14—C9 | 119.99 (13) |
C15—C4—H4 | 109.2 | C13—C14—H14 | 120.0 |
C1—C4—H4 | 109.2 | C9—C14—H14 | 120.0 |
C3—C4—H4 | 109.2 | C16—C15—C20 | 118.9 (1) |
O2—C5—C1 | 122.94 (13) | C16—C15—C4 | 120.02 (11) |
O2—C5—C6 | 119.95 (12) | C20—C15—C4 | 121.1 (1) |
C1—C5—C6 | 117.10 (11) | C17—C16—C15 | 120.76 (13) |
C5—C6—H6A | 109.5 | C17—C16—H16 | 119.6 |
C5—C6—H6B | 109.5 | C15—C16—H16 | 119.6 |
H6A—C6—H6B | 109.5 | C18—C17—C16 | 120.10 (13) |
C5—C6—H6C | 109.5 | C18—C17—H17 | 120.0 |
H6A—C6—H6C | 109.5 | C16—C17—H17 | 120.0 |
H6B—C6—H6C | 109.5 | C17—C18—C19 | 119.44 (13) |
C2—C7—H7A | 109.5 | C17—C18—H18 | 120.3 |
C2—C7—H7B | 109.5 | C19—C18—H18 | 120.3 |
H7A—C7—H7B | 109.5 | C18—C19—C20 | 120.72 (13) |
C2—C7—H7C | 109.5 | C18—C19—H19 | 119.6 |
H7A—C7—H7C | 109.5 | C20—C19—H19 | 119.6 |
H7B—C7—H7C | 109.5 | C19—C20—C15 | 120.10 (12) |
O3—C8—C9 | 121.35 (12) | C19—C20—H20 | 119.9 |
O3—C8—C3 | 119.27 (11) | C15—C20—H20 | 119.9 |
C9—C8—C3 | 119.31 (11) | ||
C5—C1—C2—O1 | 179.7 (1) | O3—C8—C9—C14 | 176.41 (13) |
C4—C1—C2—O1 | −0.7 (2) | C3—C8—C9—C14 | −0.60 (18) |
C5—C1—C2—C7 | 0.5 (2) | O3—C8—C9—C10 | −4.63 (19) |
C4—C1—C2—C7 | −179.9 (1) | C3—C8—C9—C10 | 178.36 (11) |
C3—O1—C2—C1 | −7.8 (2) | C14—C9—C10—C11 | −0.1 (2) |
C3—O1—C2—C7 | 171.6 (1) | C8—C9—C10—C11 | −179.07 (12) |
C2—O1—C3—C8 | −105.3 (1) | C9—C10—C11—C12 | 0.2 (2) |
C2—O1—C3—C4 | 12.6 (1) | C10—C11—C12—C13 | −0.1 (2) |
C2—C1—C4—C15 | −114.3 (1) | C11—C12—C13—C14 | −0.2 (2) |
C5—C1—C4—C15 | 65.3 (2) | C12—C13—C14—C9 | 0.4 (2) |
C2—C1—C4—C3 | 7.9 (1) | C10—C9—C14—C13 | −0.2 (2) |
C5—C1—C4—C3 | −172.5 (1) | C8—C9—C14—C13 | 178.71 (12) |
O1—C3—C4—C15 | 111.1 (1) | C1—C4—C15—C16 | −144.77 (12) |
C8—C3—C4—C15 | −132.2 (1) | C3—C4—C15—C16 | 100.74 (14) |
O1—C3—C4—C1 | −12.1 (1) | C1—C4—C15—C20 | 34.96 (16) |
C8—C3—C4—C1 | 104.6 (1) | C3—C4—C15—C20 | −79.53 (14) |
C2—C1—C5—O2 | 10.4 (2) | C20—C15—C16—C17 | 0.2 (2) |
C4—C1—C5—O2 | −169.2 (1) | C4—C15—C16—C17 | 179.92 (12) |
C2—C1—C5—C6 | −169.6 (1) | C15—C16—C17—C18 | −0.6 (2) |
C4—C1—C5—C6 | 10.81 (19) | C16—C17—C18—C19 | 0.5 (2) |
O1—C3—C8—O3 | 30.3 (2) | C17—C18—C19—C20 | 0.0 (2) |
C4—C3—C8—O3 | −85.7 (2) | C18—C19—C20—C15 | −0.4 (2) |
O1—C3—C8—C9 | −152.66 (11) | C16—C15—C20—C19 | 0.30 (19) |
C4—C3—C8—C9 | 91.38 (13) | C4—C15—C20—C19 | −179.43 (11) |
D—H···A | D—H | H···A | D···A | D—H···A |
C20—H20···O2i | 0.95 | 2.62 | 3.552 (2) | 166 |
C16—H16···O2ii | 0.95 | 2.63 | 3.426 (2) | 141 |
C12—H12···O3ii | 0.95 | 2.66 | 3.558 (2) | 157 |
Symmetry codes: (i) −x, −y, −z; (ii) x, −y+1/2, z+1/2. |
Experimental details
Crystal data | |
Chemical formula | C20H18O3 |
Mr | 306.34 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 150 |
a, b, c (Å) | 9.846 (2), 10.564 (2), 16.340 (3) |
β (°) | 113.023 (2) |
V (Å3) | 1564.2 (5) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.28 × 0.22 × 0.10 |
Data collection | |
Diffractometer | Bruker SMART CCD diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 1998) |
Tmin, Tmax | 0.95, 0.99 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 21162, 4750, 3623 |
Rint | 0.036 |
(sin θ/λ)max (Å−1) | 0.714 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.051, 0.149, 1.08 |
No. of reflections | 4750 |
No. of parameters | 209 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.45, −0.42 |
Computer programs: SMART (Bruker, 1999), SMART, SAINT (Bruker, 1999), SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), PLATON (Spek, 1999), SHELXL97.
O1—C2 | 1.360 (2) | C1—C5 | 1.465 (2) |
O1—C3 | 1.446 (2) | C1—C4 | 1.524 (2) |
O2—C5 | 1.232 (2) | C2—C7 | 1.487 (2) |
O3—C8 | 1.222 (2) | C3—C8 | 1.530 (2) |
C1—C2 | 1.351 (2) | C3—C4 | 1.571 (2) |
C2—O1—C3 | 108.0 (1) | O1—C3—C4 | 106.8 (1) |
C2—C1—C5 | 125.1 (1) | C8—C3—C4 | 109.7 (1) |
C2—C1—C4 | 109.5 (1) | C4—C3—H3 | 110.8 |
C5—C1—C4 | 125.4 (1) | C15—C4—C3 | 113.7 (1) |
C1—C2—O1 | 114.1 (1) | C3—C4—H4 | 109.2 |
C1—C2—C7 | 132.1 (1) | C16—C15—C20 | 118.9 (1) |
O1—C2—C7 | 113.9 (1) | C20—C15—C4 | 121.1 (1) |
O1—C3—C8 | 107.9 (1) | ||
C5—C1—C2—O1 | 179.7 (1) | C2—C1—C4—C3 | 7.9 (1) |
C4—C1—C2—O1 | −0.7 (2) | C5—C1—C4—C3 | −172.5 (1) |
C5—C1—C2—C7 | 0.5 (2) | O1—C3—C4—C15 | 111.1 (1) |
C4—C1—C2—C7 | −179.9 (1) | C8—C3—C4—C15 | −132.2 (1) |
C3—O1—C2—C1 | −7.8 (2) | O1—C3—C4—C1 | −12.1 (1) |
C3—O1—C2—C7 | 171.6 (1) | C8—C3—C4—C1 | 104.6 (1) |
C2—O1—C3—C8 | −105.3 (1) | C2—C1—C5—O2 | 10.4 (2) |
C2—O1—C3—C4 | 12.6 (1) | C4—C1—C5—O2 | −169.2 (1) |
C2—C1—C4—C15 | −114.3 (1) | O1—C3—C8—O3 | 30.3 (2) |
C5—C1—C4—C15 | 65.3 (2) | C4—C3—C8—O3 | −85.7 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
C20—H20···O2i | 0.95 | 2.62 | 3.552 (2) | 166 |
C16—H16···O2ii | 0.95 | 2.63 | 3.426 (2) | 141 |
C12—H12···O3ii | 0.95 | 2.66 | 3.558 (2) | 157 |
Symmetry codes: (i) −x, −y, −z; (ii) x, −y+1/2, z+1/2. |
Dihydrofurans represent an important class of heterocycles, characterized by highly pronounced insect antifeedant activities (Gebbinck et al., 1999), and they have been characterized by elemental analysis, IR, 1H, 13C and two-dimensional NMR spectroscopic methods. Dihydrofurans have also been found to possess antifungal (Pour et al., 2003; Kunes et al., 2001) and anti-inflammatory (Kumar et al., 2003) properties. Since the title compound, (I), has several reactive functional groups, it can also serve as a starting material for the synthesis of novel heterocycles. A series of investigations on the synthesis, NMR and crystal structure elucidation of hydrofuran derivatives is being carried out in our laboratory.
Fig. 1 shows the atom-numbering scheme adopted for (I). The two phenyl rings are planar while the five-membered dihydrofuran ring adopts a conformation intermediate between an envelope and a half-chair; this seems to be different from the conformations observed in related structures, viz. (3S,5S,1'S)-3-benzyl-5-[1'-(tert-butoxycarbonylamino)-2'-phenylethyl]- 4,5-dihydrofuran-2(3H)-one (Sopková et al., 1996), methyl 4-hydroxy-3-[4-methoxy-2-methoxymethylenoxy)phenyl]-2-{[4-methoxy-2- (methoxymethylenoxy)phenyl]methyl}-5-oxo-2,5-dihydrofuran-2-carboxylate (Boehlow et al., 1997) and 5-hydroxy-2,2-dimethyl-5-phenyl-2,5-dihydrofuran-3-carbonitrile (Ferguson, 1990). The C—C and C—O distances (Table 1) agree well with those in similar dihydrofuran derivatives.
The carbonyl group C8═O3 is oriented away from the phenyl ring at C4 to avoid electronic repulsion. The benzoyl group at C3 and the phenyl group at C4 lie on opposite sides of the dihydrofuran ring. This is evident from the torsion angle H4—C4—C3—C8 value of 9.9 (1)°; this value, close to zero, indicates that atoms H4 and C8 are eclipsed. This configuration, to avoid steric interactions between the two phenyl rings, is probably established in the cyclization step of the formation of the compound. Fig. 2 shows the arrangement of molecules as stacked layers, viewed down the b axis. Apart from the C—H···O hydrogen-bond interactions listed in Table 2, there are no other notable intermolecular contacts.