organic compounds
(3R*)-Methyl 3-[(2S*)-4,6-dimethoxy-2-(4-methoxyphenyl)-3-oxo-2,3-dihydro-1-benzofuran-2-yl]-2-methoxycarbonyl-3-phenylpropionate
aCollege of Science, China Agricultural University, Beijing 100094, People's Republic of China
*Correspondence e-mail: qinzhaohai@cau.edu.cn
The title compound, C29H28O9, was isolated from the reaction of 4,6-dimethoxy-2-(4-methoxyphenyl)-3-benzofuran and α-methoxycarbonylcinnaminate. The two aromatic rings form a dihedral angle of 22.7 (1)°. One methoxycarbonyl group is disordered between two orientations in a 0.612 (4):0.388 (4) ratio. The exhibits no significantly short intermolecular contacts.
Related literature
The title compound is a key intermediate in the synthesis of rocaglamide, see: Kraus & Sy (1989); Li et al. (2008). For the biological activity of rocaglamide derivatives, see: Zhu et al. (2007).
Experimental
Crystal data
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Data collection: CrysAlis CCD (Oxford Diffraction, 2009); cell CrysAlis RED (Oxford Diffraction, 2009); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97.
Supporting information
https://doi.org/10.1107/S1600536809042196/cv2618sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536809042196/cv2618Isup2.hkl
Under N2 atmosphere, to asolution of 4, 6-dimethoxy- 2-(4-methoxyphenyl)-3- benzofuran (3.0 g, 10 mmol) in anhydrous THF (100 ml) was added a solution of Triton B (40% in CH3OH, 0.3 ml) and a solution of α-methoxycarbonylcinnaminate(3.2 g, 14.5 mmol) in anhydrous THF (40 ml) by syringe. After stirring at 40 °C for 4 h, the solvent was removed in vacuo. To the residue was added a solution of HCl (1 mol/L, 35 ml), and this solution was extracted with CH2Cl2 (3 × 40 ml). The combined organic phase was washed with saturated NaCl solution (2 × 30 ml), dried with Na2SO4, and concentrated. The crude product was separated by silica-gel columnchromatography (petroleum ether/EtOAc, 3:1) to afford colourless crystal of compound (I).
All H atoms were positioned geometrically with C—H = 0.93 - 0.98 Å and constrained to ride on their parent atoms, with Uiso(H) = xUeq(C), where x = 1.5 for methyl H and x = 1.2 for other H atoms.
Rocaglamide (Fig. 1), featuring a cyclopenta[b]benzofuran ring system, was first isolated from the roots and stems of Aglia elliptifolia by King and co-workers in 1982. Since then, rocaglamide and related compounds have shown cytostatic and cytotoxic activity against a variety of human cancer cell lines (King et al., 1982; Zhu et al., 2007). The structural complexity of rocaglamide and its significant activity make it an attractive synthetic target. To date, several synthetic routes were developed for rocaglamide and its derivatives (Kraus et al., 1989; Li et al., 2008).
The title compound (I) is one of the key intermediates to rocaglamide in Li's strategy (Li et al., 2008). Preparation of the compound involved the reaction of 4,6-dimethoxy-2-(4-methoxyphenyl)-3-benzofuran, α-methoxycarbonylcinnaminate and Triton B (N,N,N-trimethylbenzylammonium hydroxide) for 4 h with concomitant stirring in 40 °C and purification by silica-gel (petroleumether/EtOAc, 3:1) to give colourless crystals.
In (I) (Fig. 2), two aromatic rings form a dihedral angle of 22.7 (1) °, and one methoxycarbonyl group is disordered between two orientations in an approximate ratio 3:2. The X-ray
confirms that the substance produced is a of Methyl 2-methoxycarbonyl-(3R, 4S) - and - (3S, 4R) - 4-(4, 6-dimethoxy-3-oxo -2, 3-dihydrobenzofuran-2-yl]-4-(4-methoxy-phenyl)-3-phenylpropionate as predicted by NOESY NMR experiments.The title compound is a key intermediate in the synthesis of rocaglamide, see: Kraus & Sy (1989); Li et al. (2008). For the biological activity of rocaglamide derivatives, see: Zhu et al. (2007).
Data collection: CrysAlis CCD (Oxford Diffraction, 2009); cell
CrysAlis RED (Oxford Diffraction, 2009); data reduction: CrysAlis RED (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).C29H28O9 | Z = 2 |
Mr = 520.51 | F(000) = 548 |
Triclinic, P1 | Dx = 1.349 Mg m−3 |
a = 6.901 (5) Å | Cu Kα radiation, λ = 1.54184 Å |
b = 10.478 (5) Å | Cell parameters from 21851 reflections |
c = 18.467 (5) Å | θ = 2.4–72.1° |
α = 79.838 (5)° | µ = 0.84 mm−1 |
β = 86.976 (5)° | T = 295 K |
γ = 77.097 (5)° | Block, colourless |
V = 1281.1 (12) Å3 | 0.40 × 0.36 × 0.34 mm |
Oxford Diffraction Gemini S Ultra diffractometer | 4811 independent reflections |
Radiation source: Enhance Ultra (Cu) X-ray Source | 4581 reflections with I > 2σ(I) |
Mirror monochromator | Rint = 0.018 |
Detector resolution: 15.9149 pixels mm-1 | θmax = 70.1°, θmin = 2.4° |
ω scans | h = −8→6 |
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009). | k = −12→12 |
Tmin = 0.731, Tmax = 0.764 | l = −22→22 |
24595 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)] = 0.042 | H-atom parameters constrained |
wR(F2) = 0.093 | w = 1/[σ2(Fo2) + (0.0289P)2 + 0.6245P] where P = (Fo2 + 2Fc2)/3 |
S = 1.01 | (Δ/σ)max = 0.001 |
4811 reflections | Δρmax = 0.41 e Å−3 |
378 parameters | Δρmin = −0.45 e Å−3 |
9 restraints | Extinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0365 (14) |
C29H28O9 | γ = 77.097 (5)° |
Mr = 520.51 | V = 1281.1 (12) Å3 |
Triclinic, P1 | Z = 2 |
a = 6.901 (5) Å | Cu Kα radiation |
b = 10.478 (5) Å | µ = 0.84 mm−1 |
c = 18.467 (5) Å | T = 295 K |
α = 79.838 (5)° | 0.40 × 0.36 × 0.34 mm |
β = 86.976 (5)° |
Oxford Diffraction Gemini S Ultra diffractometer | 4811 independent reflections |
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009). | 4581 reflections with I > 2σ(I) |
Tmin = 0.731, Tmax = 0.764 | Rint = 0.018 |
24595 measured reflections |
R[F2 > 2σ(F2)] = 0.042 | 9 restraints |
wR(F2) = 0.093 | H-atom parameters constrained |
S = 1.01 | Δρmax = 0.41 e Å−3 |
4811 reflections | Δρmin = −0.45 e Å−3 |
378 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 | Occ. (<1) | |
O1 | 0.72974 (16) | −0.00047 (10) | 0.17466 (6) | 0.0477 (3) | |
O2 | 0.11720 (18) | 0.08988 (12) | 0.05005 (7) | 0.0560 (3) | |
O3 | 0.74032 (15) | 0.21665 (10) | 0.26672 (6) | 0.0441 (3) | |
O4 | 0.23465 (13) | 0.35531 (9) | 0.22326 (5) | 0.0339 (2) | |
O5 | 0.1979 (2) | 0.09372 (13) | 0.55766 (6) | 0.0616 (3) | |
O8 | 0.47464 (18) | 0.74181 (12) | 0.28233 (9) | 0.0681 (4) | |
O9 | 0.14431 (16) | 0.81607 (10) | 0.27886 (7) | 0.0517 (3) | |
C1 | 0.2267 (2) | 0.12553 (15) | 0.09905 (8) | 0.0406 (3) | |
C2 | 0.4180 (2) | 0.04509 (15) | 0.11022 (8) | 0.0445 (4) | |
H2 | 0.4594 | −0.0263 | 0.0853 | 0.053* | |
C3 | 0.5450 (2) | 0.07168 (14) | 0.15815 (8) | 0.0374 (3) | |
C4 | 0.4790 (2) | 0.18239 (13) | 0.19409 (7) | 0.0338 (3) | |
C5 | 0.2860 (2) | 0.25550 (12) | 0.18279 (7) | 0.0320 (3) | |
C6 | 0.1540 (2) | 0.23139 (14) | 0.13594 (7) | 0.0363 (3) | |
H6 | 0.0254 | 0.2825 | 0.1295 | 0.044* | |
C7 | 0.3966 (2) | 0.34343 (13) | 0.27287 (7) | 0.0324 (3) | |
C8 | 0.5705 (2) | 0.24013 (13) | 0.24547 (7) | 0.0334 (3) | |
C9 | 0.3410 (2) | 0.27976 (13) | 0.34983 (7) | 0.0341 (3) | |
C10 | 0.4720 (2) | 0.26054 (15) | 0.40736 (8) | 0.0424 (3) | |
H10 | 0.5905 | 0.2894 | 0.3987 | 0.051* | |
C11 | 0.4297 (2) | 0.19920 (16) | 0.47741 (8) | 0.0469 (4) | |
H11 | 0.5184 | 0.1883 | 0.5153 | 0.056* | |
C12 | 0.2553 (2) | 0.15417 (15) | 0.49079 (8) | 0.0444 (4) | |
C13 | 0.1257 (2) | 0.16977 (16) | 0.43329 (9) | 0.0460 (4) | |
H13 | 0.0095 | 0.1380 | 0.4416 | 0.055* | |
C14 | 0.1678 (2) | 0.23218 (14) | 0.36369 (8) | 0.0392 (3) | |
H14 | 0.0793 | 0.2424 | 0.3257 | 0.047* | |
C15 | 0.3217 (3) | 0.0827 (2) | 0.61877 (10) | 0.0685 (5) | |
H15B | 0.4527 | 0.0335 | 0.6091 | 0.103* | |
H15C | 0.2670 | 0.0374 | 0.6620 | 0.103* | |
H15A | 0.3289 | 0.1699 | 0.6263 | 0.103* | |
C16 | 0.4442 (2) | 0.48256 (13) | 0.26704 (7) | 0.0334 (3) | |
H16 | 0.5424 | 0.4762 | 0.3047 | 0.040* | |
C17 | 0.5380 (2) | 0.52433 (13) | 0.19253 (8) | 0.0347 (3) | |
C18 | 0.4260 (2) | 0.57228 (18) | 0.12944 (9) | 0.0498 (4) | |
H18 | 0.2887 | 0.5813 | 0.1324 | 0.060* | |
C19 | 0.5154 (3) | 0.6070 (2) | 0.06191 (10) | 0.0610 (5) | |
H19 | 0.4378 | 0.6389 | 0.0202 | 0.073* | |
C20 | 0.7178 (3) | 0.59466 (18) | 0.05638 (10) | 0.0566 (4) | |
H20 | 0.7779 | 0.6175 | 0.0111 | 0.068* | |
C21 | 0.8301 (2) | 0.54818 (16) | 0.11845 (10) | 0.0514 (4) | |
H21 | 0.9672 | 0.5397 | 0.1151 | 0.062* | |
C22 | 0.7418 (2) | 0.51363 (14) | 0.18602 (9) | 0.0423 (3) | |
H22 | 0.8203 | 0.4828 | 0.2276 | 0.051* | |
C23 | 0.2594 (2) | 0.58820 (13) | 0.28276 (8) | 0.0362 (3) | |
H23 | 0.1610 | 0.5978 | 0.2447 | 0.043* | |
C24 | 0.1603 (2) | 0.56062 (15) | 0.35796 (8) | 0.0455 (4) | |
C26 | 0.3135 (2) | 0.72205 (13) | 0.28050 (8) | 0.0408 (3) | |
C27 | 0.1644 (3) | 0.94722 (15) | 0.28982 (12) | 0.0638 (5) | |
H27B | 0.0520 | 1.0130 | 0.2692 | 0.096* | |
H27C | 0.2841 | 0.9664 | 0.2659 | 0.096* | |
H27A | 0.1703 | 0.9484 | 0.3415 | 0.096* | |
C28 | 0.7892 (3) | −0.12487 (18) | 0.14867 (11) | 0.0616 (5) | |
H28B | 0.7877 | −0.1093 | 0.0959 | 0.092* | |
H28A | 0.6986 | −0.1806 | 0.1675 | 0.092* | |
H28C | 0.9210 | −0.1679 | 0.1652 | 0.092* | |
C29 | −0.0736 (3) | 0.17228 (18) | 0.03147 (10) | 0.0542 (4) | |
H29C | −0.1343 | 0.1365 | −0.0037 | 0.081* | |
H29B | −0.0592 | 0.2603 | 0.0106 | 0.081* | |
H29A | −0.1558 | 0.1755 | 0.0750 | 0.081* | |
O6A | 0.2258 (6) | 0.5551 (6) | 0.41638 (11) | 0.0610 (9) | 0.612 (4) |
O7A | −0.0279 (4) | 0.5512 (5) | 0.34725 (13) | 0.0462 (7) | 0.612 (4) |
C25A | −0.1494 (4) | 0.5308 (3) | 0.41401 (13) | 0.0527 (8) | 0.612 (4) |
H25A | −0.2861 | 0.5443 | 0.4008 | 0.079* | 0.612 (4) |
H25B | −0.1368 | 0.5929 | 0.4450 | 0.079* | 0.612 (4) |
H25C | −0.1050 | 0.4418 | 0.4399 | 0.079* | 0.612 (4) |
O6B | 0.0009 (7) | 0.5422 (10) | 0.3754 (4) | 0.097 (3) | 0.388 (4) |
O7B | 0.2974 (7) | 0.5644 (8) | 0.40674 (19) | 0.074 (2) | 0.388 (4) |
C25B | 0.2580 (11) | 0.5464 (7) | 0.4862 (2) | 0.090 (2) | 0.388 (4) |
H25D | 0.3803 | 0.5331 | 0.5117 | 0.135* | 0.388 (4) |
H25E | 0.2003 | 0.4702 | 0.5007 | 0.135* | 0.388 (4) |
H25F | 0.1674 | 0.6239 | 0.4981 | 0.135* | 0.388 (4) |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0465 (6) | 0.0393 (6) | 0.0547 (6) | 0.0048 (5) | −0.0024 (5) | −0.0187 (5) |
O2 | 0.0601 (7) | 0.0565 (7) | 0.0579 (7) | −0.0070 (6) | −0.0148 (6) | −0.0299 (6) |
O3 | 0.0363 (6) | 0.0397 (6) | 0.0555 (6) | −0.0030 (4) | −0.0079 (5) | −0.0104 (5) |
O4 | 0.0358 (5) | 0.0298 (5) | 0.0365 (5) | −0.0017 (4) | −0.0062 (4) | −0.0120 (4) |
O5 | 0.0730 (8) | 0.0697 (8) | 0.0418 (6) | −0.0249 (7) | 0.0023 (6) | 0.0023 (6) |
O8 | 0.0491 (7) | 0.0482 (7) | 0.1165 (12) | −0.0139 (6) | −0.0003 (7) | −0.0354 (7) |
O9 | 0.0498 (6) | 0.0290 (5) | 0.0748 (8) | −0.0026 (4) | −0.0009 (5) | −0.0125 (5) |
C1 | 0.0502 (9) | 0.0392 (8) | 0.0360 (7) | −0.0118 (6) | −0.0038 (6) | −0.0121 (6) |
C2 | 0.0530 (9) | 0.0384 (8) | 0.0438 (8) | −0.0044 (7) | 0.0009 (7) | −0.0193 (6) |
C3 | 0.0410 (8) | 0.0316 (7) | 0.0379 (7) | −0.0031 (6) | 0.0028 (6) | −0.0089 (6) |
C4 | 0.0379 (7) | 0.0294 (7) | 0.0338 (7) | −0.0055 (5) | 0.0006 (5) | −0.0070 (5) |
C5 | 0.0396 (7) | 0.0262 (6) | 0.0302 (6) | −0.0063 (5) | 0.0010 (5) | −0.0065 (5) |
C6 | 0.0398 (7) | 0.0338 (7) | 0.0352 (7) | −0.0058 (6) | −0.0031 (6) | −0.0081 (6) |
C7 | 0.0344 (7) | 0.0290 (6) | 0.0343 (7) | −0.0043 (5) | −0.0058 (5) | −0.0083 (5) |
C8 | 0.0366 (7) | 0.0270 (6) | 0.0352 (7) | −0.0048 (5) | −0.0016 (5) | −0.0039 (5) |
C9 | 0.0398 (7) | 0.0267 (6) | 0.0359 (7) | −0.0045 (5) | −0.0025 (6) | −0.0083 (5) |
C10 | 0.0442 (8) | 0.0438 (8) | 0.0408 (8) | −0.0132 (7) | −0.0055 (6) | −0.0057 (6) |
C11 | 0.0538 (9) | 0.0487 (9) | 0.0382 (8) | −0.0113 (7) | −0.0093 (7) | −0.0047 (7) |
C12 | 0.0558 (9) | 0.0377 (8) | 0.0383 (8) | −0.0091 (7) | 0.0024 (7) | −0.0052 (6) |
C13 | 0.0468 (9) | 0.0450 (8) | 0.0486 (9) | −0.0160 (7) | 0.0019 (7) | −0.0075 (7) |
C14 | 0.0419 (8) | 0.0360 (7) | 0.0411 (8) | −0.0088 (6) | −0.0047 (6) | −0.0091 (6) |
C15 | 0.0890 (15) | 0.0740 (13) | 0.0387 (9) | −0.0189 (11) | −0.0037 (9) | 0.0023 (8) |
C16 | 0.0363 (7) | 0.0289 (6) | 0.0356 (7) | −0.0054 (5) | −0.0043 (5) | −0.0083 (5) |
C17 | 0.0377 (7) | 0.0272 (6) | 0.0400 (7) | −0.0062 (5) | −0.0014 (6) | −0.0083 (5) |
C18 | 0.0398 (8) | 0.0637 (10) | 0.0437 (8) | −0.0103 (7) | −0.0041 (7) | −0.0032 (7) |
C19 | 0.0608 (11) | 0.0768 (13) | 0.0413 (9) | −0.0150 (9) | −0.0057 (8) | 0.0025 (8) |
C20 | 0.0624 (11) | 0.0554 (10) | 0.0505 (10) | −0.0165 (8) | 0.0127 (8) | −0.0040 (8) |
C21 | 0.0413 (8) | 0.0438 (9) | 0.0672 (11) | −0.0104 (7) | 0.0096 (8) | −0.0061 (8) |
C22 | 0.0389 (8) | 0.0344 (7) | 0.0522 (9) | −0.0062 (6) | −0.0041 (6) | −0.0046 (6) |
C23 | 0.0401 (8) | 0.0305 (7) | 0.0387 (7) | −0.0058 (6) | −0.0008 (6) | −0.0103 (6) |
C24 | 0.0602 (10) | 0.0313 (7) | 0.0444 (9) | −0.0045 (7) | 0.0049 (8) | −0.0133 (6) |
C26 | 0.0456 (9) | 0.0332 (7) | 0.0448 (8) | −0.0066 (6) | −0.0005 (6) | −0.0121 (6) |
C27 | 0.0717 (12) | 0.0285 (8) | 0.0913 (14) | −0.0093 (8) | 0.0114 (10) | −0.0159 (8) |
C28 | 0.0641 (11) | 0.0448 (9) | 0.0710 (12) | 0.0118 (8) | −0.0022 (9) | −0.0268 (9) |
C29 | 0.0510 (10) | 0.0614 (11) | 0.0568 (10) | −0.0158 (8) | −0.0098 (8) | −0.0207 (8) |
O6A | 0.074 (2) | 0.077 (2) | 0.0306 (14) | −0.0115 (17) | 0.0055 (14) | −0.0125 (15) |
O7A | 0.0501 (14) | 0.0492 (15) | 0.0386 (13) | −0.0111 (9) | 0.0131 (10) | −0.0091 (13) |
C25A | 0.0483 (16) | 0.0634 (18) | 0.0461 (15) | −0.0120 (13) | 0.0125 (12) | −0.0130 (13) |
O6B | 0.106 (5) | 0.065 (3) | 0.106 (5) | −0.016 (4) | 0.078 (4) | −0.006 (5) |
O7B | 0.129 (6) | 0.050 (2) | 0.039 (2) | −0.013 (4) | 0.047 (3) | −0.0138 (16) |
C25B | 0.127 (6) | 0.094 (5) | 0.057 (3) | −0.035 (4) | 0.029 (3) | −0.029 (3) |
O1—C3 | 1.3485 (19) | C16—C23 | 1.543 (2) |
O1—C28 | 1.4349 (19) | C16—H16 | 0.9800 |
O2—C1 | 1.3589 (18) | C17—C22 | 1.386 (2) |
O2—C29 | 1.426 (2) | C17—C18 | 1.387 (2) |
O3—C8 | 1.2141 (18) | C18—C19 | 1.388 (2) |
O4—C5 | 1.3638 (16) | C18—H18 | 0.9300 |
O4—C7 | 1.4524 (16) | C19—C20 | 1.374 (3) |
O5—C12 | 1.3665 (19) | C19—H19 | 0.9300 |
O5—C15 | 1.424 (2) | C20—C21 | 1.371 (3) |
O8—C26 | 1.1788 (18) | C20—H20 | 0.9300 |
O9—C26 | 1.3470 (18) | C21—C22 | 1.385 (2) |
O9—C27 | 1.4610 (17) | C21—H21 | 0.9300 |
C1—C6 | 1.389 (2) | C22—H22 | 0.9300 |
C1—C2 | 1.402 (2) | C23—C26 | 1.523 (2) |
C2—C3 | 1.381 (2) | C23—C24 | 1.525 (2) |
C2—H2 | 0.9300 | C23—H23 | 0.9800 |
C3—C4 | 1.4133 (19) | C24—O6B | 1.178 (2) |
C4—C5 | 1.386 (2) | C24—O6A | 1.1786 (18) |
C4—C8 | 1.4497 (19) | C24—O7B | 1.3519 (19) |
C5—C6 | 1.380 (2) | C24—O7A | 1.352 (2) |
C6—H6 | 0.9300 | C27—H27B | 0.9600 |
C7—C9 | 1.5280 (19) | C27—H27C | 0.9600 |
C7—C16 | 1.5491 (19) | C27—H27A | 0.9600 |
C7—C8 | 1.5545 (19) | C28—H28B | 0.9600 |
C9—C14 | 1.389 (2) | C28—H28A | 0.9600 |
C9—C10 | 1.390 (2) | C28—H28C | 0.9600 |
C10—C11 | 1.387 (2) | C29—H29C | 0.9600 |
C10—H10 | 0.9300 | C29—H29B | 0.9600 |
C11—C12 | 1.383 (2) | C29—H29A | 0.9600 |
C11—H11 | 0.9300 | O7A—C25A | 1.4652 (18) |
C12—C13 | 1.389 (2) | C25A—H25A | 0.9600 |
C13—C14 | 1.383 (2) | C25A—H25B | 0.9600 |
C13—H13 | 0.9300 | C25A—H25C | 0.9600 |
C14—H14 | 0.9300 | O7B—C25B | 1.4642 (19) |
C15—H15B | 0.9600 | C25B—H25D | 0.9600 |
C15—H15C | 0.9600 | C25B—H25E | 0.9600 |
C15—H15A | 0.9600 | C25B—H25F | 0.9600 |
C16—C17 | 1.5243 (19) | ||
C3—O1—C28 | 117.37 (13) | C22—C17—C16 | 120.09 (13) |
C1—O2—C29 | 117.97 (13) | C18—C17—C16 | 122.13 (13) |
C5—O4—C7 | 107.90 (10) | C17—C18—C19 | 121.03 (16) |
C12—O5—C15 | 117.50 (15) | C17—C18—H18 | 119.5 |
C26—O9—C27 | 116.34 (13) | C19—C18—H18 | 119.5 |
O2—C1—C6 | 122.80 (14) | C20—C19—C18 | 120.39 (16) |
O2—C1—C2 | 114.41 (13) | C20—C19—H19 | 119.8 |
C6—C1—C2 | 122.78 (13) | C18—C19—H19 | 119.8 |
C3—C2—C1 | 120.13 (13) | C21—C20—C19 | 119.14 (16) |
C3—C2—H2 | 119.9 | C21—C20—H20 | 120.4 |
C1—C2—H2 | 119.9 | C19—C20—H20 | 120.4 |
O1—C3—C2 | 125.39 (13) | C20—C21—C22 | 120.77 (16) |
O1—C3—C4 | 116.06 (13) | C20—C21—H21 | 119.6 |
C2—C3—C4 | 118.54 (13) | C22—C21—H21 | 119.6 |
C5—C4—C3 | 118.67 (13) | C21—C22—C17 | 120.88 (15) |
C5—C4—C8 | 107.82 (12) | C21—C22—H22 | 119.6 |
C3—C4—C8 | 133.49 (13) | C17—C22—H22 | 119.6 |
O4—C5—C6 | 121.85 (12) | C26—C23—C24 | 104.52 (11) |
O4—C5—C4 | 113.69 (11) | C26—C23—C16 | 110.65 (12) |
C6—C5—C4 | 124.46 (13) | C24—C23—C16 | 115.72 (12) |
C5—C6—C1 | 115.31 (13) | C26—C23—H23 | 108.6 |
C5—C6—H6 | 122.3 | C24—C23—H23 | 108.6 |
C1—C6—H6 | 122.3 | C16—C23—H23 | 108.6 |
O4—C7—C9 | 109.10 (11) | O6B—C24—O6A | 99.9 (4) |
O4—C7—C16 | 107.85 (10) | O6B—C24—O7B | 123.3 (4) |
C9—C7—C16 | 115.55 (11) | O6A—C24—O7B | 23.4 (3) |
O4—C7—C8 | 104.70 (10) | O6B—C24—O7A | 23.9 (4) |
C9—C7—C8 | 106.01 (11) | O6A—C24—O7A | 123.6 (2) |
C16—C7—C8 | 113.05 (12) | O7B—C24—O7A | 147.0 (3) |
O3—C8—C4 | 131.22 (13) | O6B—C24—C23 | 131.9 (4) |
O3—C8—C7 | 124.37 (12) | O6A—C24—C23 | 128.2 (2) |
C4—C8—C7 | 104.38 (12) | O7B—C24—C23 | 104.8 (2) |
C14—C9—C10 | 118.20 (13) | O7A—C24—C23 | 108.04 (14) |
C14—C9—C7 | 122.03 (12) | O8—C26—O9 | 124.70 (14) |
C10—C9—C7 | 119.65 (13) | O8—C26—C23 | 126.77 (13) |
C11—C10—C9 | 121.33 (15) | O9—C26—C23 | 108.48 (12) |
C11—C10—H10 | 119.3 | O9—C27—H27B | 109.5 |
C9—C10—H10 | 119.3 | O9—C27—H27C | 109.5 |
C12—C11—C10 | 119.91 (14) | H27B—C27—H27C | 109.5 |
C12—C11—H11 | 120.0 | O9—C27—H27A | 109.5 |
C10—C11—H11 | 120.0 | H27B—C27—H27A | 109.5 |
O5—C12—C11 | 124.79 (15) | H27C—C27—H27A | 109.5 |
O5—C12—C13 | 115.96 (15) | O1—C28—H28B | 109.5 |
C11—C12—C13 | 119.25 (14) | O1—C28—H28A | 109.5 |
C14—C13—C12 | 120.55 (15) | H28B—C28—H28A | 109.5 |
C14—C13—H13 | 119.7 | O1—C28—H28C | 109.5 |
C12—C13—H13 | 119.7 | H28B—C28—H28C | 109.5 |
C13—C14—C9 | 120.73 (14) | H28A—C28—H28C | 109.5 |
C13—C14—H14 | 119.6 | O2—C29—H29C | 109.5 |
C9—C14—H14 | 119.6 | O2—C29—H29B | 109.5 |
O5—C15—H15B | 109.5 | H29C—C29—H29B | 109.5 |
O5—C15—H15C | 109.5 | O2—C29—H29A | 109.5 |
H15B—C15—H15C | 109.5 | H29C—C29—H29A | 109.5 |
O5—C15—H15A | 109.5 | H29B—C29—H29A | 109.5 |
H15B—C15—H15A | 109.5 | C24—O7A—C25A | 115.6 (2) |
H15C—C15—H15A | 109.5 | C24—O7B—C25B | 122.2 (4) |
C17—C16—C23 | 111.16 (11) | O7B—C25B—H25D | 109.5 |
C17—C16—C7 | 111.15 (11) | O7B—C25B—H25E | 109.5 |
C23—C16—C7 | 111.99 (12) | H25D—C25B—H25E | 109.5 |
C17—C16—H16 | 107.4 | O7B—C25B—H25F | 109.5 |
C23—C16—H16 | 107.4 | H25D—C25B—H25F | 109.5 |
C7—C16—H16 | 107.4 | H25E—C25B—H25F | 109.5 |
C22—C17—C18 | 117.78 (14) | ||
C29—O2—C1—C6 | 5.6 (2) | C11—C12—C13—C14 | −1.4 (2) |
C29—O2—C1—C2 | −175.50 (14) | C12—C13—C14—C9 | 0.4 (2) |
O2—C1—C2—C3 | 179.32 (14) | C10—C9—C14—C13 | 1.3 (2) |
C6—C1—C2—C3 | −1.7 (2) | C7—C9—C14—C13 | 177.15 (13) |
C28—O1—C3—C2 | −9.3 (2) | O4—C7—C16—C17 | −69.31 (14) |
C28—O1—C3—C4 | 170.16 (14) | C9—C7—C16—C17 | 168.34 (11) |
C1—C2—C3—O1 | 178.22 (14) | C8—C7—C16—C17 | 45.95 (15) |
C1—C2—C3—C4 | −1.2 (2) | O4—C7—C16—C23 | 55.69 (14) |
O1—C3—C4—C5 | −176.09 (12) | C9—C7—C16—C23 | −66.66 (15) |
C2—C3—C4—C5 | 3.4 (2) | C8—C7—C16—C23 | 170.95 (11) |
O1—C3—C4—C8 | 1.8 (2) | C23—C16—C17—C22 | 133.41 (13) |
C2—C3—C4—C8 | −178.72 (15) | C7—C16—C17—C22 | −101.13 (14) |
C7—O4—C5—C6 | 173.08 (12) | C23—C16—C17—C18 | −47.31 (18) |
C7—O4—C5—C4 | −6.36 (15) | C7—C16—C17—C18 | 78.15 (17) |
C3—C4—C5—O4 | 176.52 (12) | C22—C17—C18—C19 | 0.7 (2) |
C8—C4—C5—O4 | −1.89 (16) | C16—C17—C18—C19 | −178.61 (15) |
C3—C4—C5—C6 | −2.9 (2) | C17—C18—C19—C20 | −0.1 (3) |
C8—C4—C5—C6 | 178.68 (13) | C18—C19—C20—C21 | −0.3 (3) |
O4—C5—C6—C1 | −179.29 (12) | C19—C20—C21—C22 | 0.1 (3) |
C4—C5—C6—C1 | 0.1 (2) | C20—C21—C22—C17 | 0.4 (2) |
O2—C1—C6—C5 | −178.88 (13) | C18—C17—C22—C21 | −0.8 (2) |
C2—C1—C6—C5 | 2.3 (2) | C16—C17—C22—C21 | 178.48 (13) |
C5—O4—C7—C9 | −101.91 (12) | C17—C16—C23—C26 | −57.94 (15) |
C5—O4—C7—C16 | 131.87 (11) | C7—C16—C23—C26 | 177.07 (11) |
C5—O4—C7—C8 | 11.22 (13) | C17—C16—C23—C24 | −176.55 (11) |
C5—C4—C8—O3 | −173.21 (14) | C7—C16—C23—C24 | 58.46 (15) |
C3—C4—C8—O3 | 8.7 (3) | C26—C23—C24—O6B | 121.0 (7) |
C5—C4—C8—C7 | 8.64 (14) | C16—C23—C24—O6B | −117.0 (7) |
C3—C4—C8—C7 | −169.44 (15) | C26—C23—C24—O6A | −57.0 (4) |
O4—C7—C8—O3 | 169.64 (13) | C16—C23—C24—O6A | 65.0 (4) |
C9—C7—C8—O3 | −75.06 (16) | C26—C23—C24—O7B | −57.3 (4) |
C16—C7—C8—O3 | 52.51 (18) | C16—C23—C24—O7B | 64.7 (4) |
O4—C7—C8—C4 | −12.04 (13) | C26—C23—C24—O7A | 119.1 (3) |
C9—C7—C8—C4 | 103.26 (12) | C16—C23—C24—O7A | −119.0 (3) |
C16—C7—C8—C4 | −129.18 (12) | C27—O9—C26—O8 | −8.3 (2) |
O4—C7—C9—C14 | 5.46 (17) | C27—O9—C26—C23 | 169.40 (14) |
C16—C7—C9—C14 | 127.14 (14) | C24—C23—C26—O8 | 110.02 (19) |
C8—C7—C9—C14 | −106.80 (15) | C16—C23—C26—O8 | −15.2 (2) |
O4—C7—C9—C10 | −178.71 (11) | C24—C23—C26—O9 | −67.62 (15) |
C16—C7—C9—C10 | −57.03 (17) | C16—C23—C26—O9 | 167.16 (12) |
C8—C7—C9—C10 | 69.03 (15) | O6B—C24—O7A—C25A | 6.4 (13) |
C14—C9—C10—C11 | −1.9 (2) | O6A—C24—O7A—C25A | −1.0 (6) |
C7—C9—C10—C11 | −177.88 (13) | O7B—C24—O7A—C25A | −3.8 (9) |
C9—C10—C11—C12 | 0.9 (2) | C23—C24—O7A—C25A | −177.3 (3) |
C15—O5—C12—C11 | 3.5 (2) | O6B—C24—O7B—C25B | −0.3 (11) |
C15—O5—C12—C13 | −176.57 (16) | O6A—C24—O7B—C25B | −1.2 (9) |
C10—C11—C12—O5 | −179.32 (15) | O7A—C24—O7B—C25B | 4.6 (13) |
C10—C11—C12—C13 | 0.8 (2) | C23—C24—O7B—C25B | 178.2 (6) |
O5—C12—C13—C14 | 178.68 (14) |
Experimental details
Crystal data | |
Chemical formula | C29H28O9 |
Mr | 520.51 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 295 |
a, b, c (Å) | 6.901 (5), 10.478 (5), 18.467 (5) |
α, β, γ (°) | 79.838 (5), 86.976 (5), 77.097 (5) |
V (Å3) | 1281.1 (12) |
Z | 2 |
Radiation type | Cu Kα |
µ (mm−1) | 0.84 |
Crystal size (mm) | 0.40 × 0.36 × 0.34 |
Data collection | |
Diffractometer | Oxford Diffraction Gemini S Ultra |
Absorption correction | Multi-scan (CrysAlis PRO; Oxford Diffraction, 2009). |
Tmin, Tmax | 0.731, 0.764 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 24595, 4811, 4581 |
Rint | 0.018 |
(sin θ/λ)max (Å−1) | 0.610 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.042, 0.093, 1.01 |
No. of reflections | 4811 |
No. of parameters | 378 |
No. of restraints | 9 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.41, −0.45 |
Computer programs: CrysAlis CCD (Oxford Diffraction, 2009), CrysAlis RED (Oxford Diffraction, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997).
Acknowledgements
We acknowledge financial support of this investigation by the National Natural Science Foundation of China (grant No. 20772151).
References
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
King, M. L., Chiang, C. C., Ling, H. C., Fujita, E., Ochiai, M. & McPhail, A. T. (1982). J. Chem. Soc. Chem. Commun. 20, 1150–1151. Google Scholar
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This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
Rocaglamide (Fig. 1), featuring a cyclopenta[b]benzofuran ring system, was first isolated from the roots and stems of Aglia elliptifolia by King and co-workers in 1982. Since then, rocaglamide and related compounds have shown cytostatic and cytotoxic activity against a variety of human cancer cell lines (King et al., 1982; Zhu et al., 2007). The structural complexity of rocaglamide and its significant activity make it an attractive synthetic target. To date, several synthetic routes were developed for rocaglamide and its derivatives (Kraus et al., 1989; Li et al., 2008).
The title compound (I) is one of the key intermediates to rocaglamide in Li's strategy (Li et al., 2008). Preparation of the compound involved the reaction of 4,6-dimethoxy-2-(4-methoxyphenyl)-3-benzofuran, α-methoxycarbonylcinnaminate and Triton B (N,N,N-trimethylbenzylammonium hydroxide) for 4 h with concomitant stirring in 40 °C and purification by silica-gel column chromatography (petroleumether/EtOAc, 3:1) to give colourless crystals.
In (I) (Fig. 2), two aromatic rings form a dihedral angle of 22.7 (1) °, and one methoxycarbonyl group is disordered between two orientations in an approximate ratio 3:2. The X-ray crystal structure confirms that the substance produced is a racemic mixture of Methyl 2-methoxycarbonyl-(3R, 4S) - and - (3S, 4R) - 4-(4, 6-dimethoxy-3-oxo -2, 3-dihydrobenzofuran-2-yl]-4-(4-methoxy-phenyl)-3-phenylpropionate as predicted by NOESY NMR experiments.