organic compounds
Isopropyl ent-15α-bromo-16-oxobeyeran-19-oate
aSchool of Chemistry and Chemical Engineering, Institute of Pharmaceutical Engineering, Southeast University, Nanjing 210096, People's Republic of China
*Correspondence e-mail: junq.chen@yahoo.com.cn
The title compound, C23H35BrO3, synthesized by esterification and bromination of isosteviol, comprises a fused four-ring system. Two of the six-membered rings adopt a regular chair conformation, whereas the remaining six-membered ring is an unsymmetrical distorted chair. The stereochemistry at the two six-membered ring junctions is trans, while the five-membered ring adopts an envelope conformation.
Related literature
For the pharmacological activity of isosteviol, see: Liu et al. (2001); Mizushina et al. (2005); Wong et al. (2004); Xu et al. (2007). For ring conformations, see: Cremer & Pople (1975). For the synthesis of isosteviol derivates via esterification and bromination, see: Cai et al. (2009); Shi (2010); Wu et al. (2009).
Experimental
Crystal data
|
Data collection: SMART (Bruker, 1999); cell SAINT (Bruker, 1999); data reduction: SAINT; 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: SHELXTL and PLATON (Spek, 2009).
Supporting information
https://doi.org/10.1107/S1600536810002138/fj2269sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810002138/fj2269Isup2.hkl
Isosteviol was obtained by hydrolysis of stevioside with 10% sulfuric acid at 95 °C for 7 h and recrystallization from ethanol gave colorless crystals of isosteviol in 80% yield. Isosteviol (5 g, 16 mmol), K2CO3 (3.3 g, 32 mmol) and 2-bromopropane (2 ml, 21 mmol) were dissolved in 100 ml acetonitrile. After reflux of the above mixture for 5.5 h, the resulting mixture was cooled to room temperature, and then distilled to one third volume under reduced pressure. The residue was poured into ice water, and the resulting precipitates were collected by filtration. The crude product was purified by recrystallization with ethanol to afford isopropyl ent-16-oxobeyeran-19-oate (5.4 g, 95%).
Isopropyl ent-16-oxobeyeran-19-oate (3.6 g, 10 mmol) and N-bromosuccinimide (5.3 g, 30 mmol) were dissolved in 50 ml tetrachloromethane. After reflux of the above mixture for 11.5 h, the resulting mixture was cooled to room temperature, and then distilled under reduced pressure. The residue was purified by δH p.p.m.: 0.79(s, 3H), 1.10(s, 3H), 1.19(s, 3H), 1.24–1.26(q, 6H), 1.09–2.21(m, 18H), 4.51–4.52(d, 1H, J=2.63 Hz), 4.96–5.01(m, 1H); 13C NMR(75 MHz, CDCl3), δC p.p.m.: 13.84, 18.91, 19.99, 20.70, 20.85, 21.63, 21.70, 28.86, 37.84, 37.89, 38.48, 38.85, 39.50, 43.01, 43.72, 48.35, 50.06, 56.01, 56.10, 57.20, 67.38, 176.46, 215.73; MS (ESI): [M+H]+ 439.2, [M+K]+ 477.1; IR(KBr): ν 2954.56, 1743.42, 1716.42 cm-1; Anal. calcd for C23H35BrO3 (%): C 62.87, H 8.03, Found: C 62.81, H 7.89.
on silica (petroleum ether/ethyl acetate = 60:1, v/v) to give the title compound (4.0 g, 91%). Crystals of the title compound suitable for X-ray diffraction were obtained by slow evaporation of ethanol solution at room temperature. m.p. 396–397 K; 1H NMR(500 MHz, CDCl3),All H atoms were placed in geometrical positions and constrained to ride on their parent atoms with C–H distances in the range 0.96–0.98 Å, and included in the final cycles of
using a riding model, with Uiso(H) = 1.5Ueq(C) for methyl H and 1.2Ueq(C) for other H atoms.Isosteviol is a tetracyclic diterpenoid with a beyerane skeleton, which has good pharmacological activity against broad spectrum significant diseases including ischemia-reperfusion injury, hypertension, and cancer (Wong et al., 2004; Liu, et al., 2001; Xu, et al., 2007; Mizushina et al., 2005). The title compound was obtained by esterification and bromination of isosteviol, respectively. The molecule structure of (I) contains a fused four-ring system A/B/C/D (Fig. 1). The A/B ring and B/C junction are trans-fused, and C/D is θ= 19.3 (4)° and φ= 243.1 (14)° (Cremer & Pople, 1975). The distortion may be attributed to the narrowing of the C9—C16—C12 bond angle to 103.8 (4)°. The five-membered ring D adopts an with atom C16 displaced from the C9/C10/C11/C12 plane by 0.281 (5) Å. The C17—C1—C2—C3 torsion angle of -73.8 (5)° describes the β-orientation of the isopropyl ester group with respect to the ent-kaurane nucleus.
-fused. Rings A and B adopt chair conformations and ring C is in a distorted chair conformation, with puckering amplitude Q = 0.641 (5) Å,For the pharmacological activity of isosteviol, see: Liu et al. (2001); Mizushina et al. (2005); Wong et al. (2004); Xu et al. (2007). For ring conformations, see: Cremer & Pople (1975). For the synthesis of isosteviol derivates via esterification and bromination, see: Cai et al. (2009); Shi (2010); Wu et al. (2009).
Data collection: SMART (Bruker, 1999); cell
SAINT (Bruker, 1999); data reduction: SAINT (Bruker, 1999); 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: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).Fig. 1. The molecular structure of the title compound with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. |
C23H35BrO3 | Dx = 1.300 Mg m−3 |
Mr = 439.42 | Melting point = 396–397 K |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 2087 reflections |
a = 11.203 (3) Å | θ = 2.2–17.6° |
b = 11.800 (3) Å | µ = 1.85 mm−1 |
c = 16.988 (5) Å | T = 298 K |
V = 2245.8 (11) Å3 | Block, colourless |
Z = 4 | 0.50 × 0.45 × 0.41 mm |
F(000) = 928 |
Bruker SMART CCD area-detector diffractometer | 3944 independent reflections |
Radiation source: fine-focus sealed tube | 2383 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.093 |
phi and ω scans | θmax = 25.0°, θmin = 2.1° |
Absorption correction: multi-scan (SADABS; Bruker, 1999) | h = −13→12 |
Tmin = 0.458, Tmax = 0.518 | k = −9→14 |
11796 measured reflections | l = −20→19 |
Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
Least-squares matrix: full | H-atom parameters constrained |
R[F2 > 2σ(F2)] = 0.047 | w = 1/[σ2(Fo2) + (0.0375P)2] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.108 | (Δ/σ)max < 0.001 |
S = 0.96 | Δρmax = 0.40 e Å−3 |
3944 reflections | Δρmin = −0.26 e Å−3 |
245 parameters | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
0 restraints | Extinction coefficient: 0.0190 (12) |
Primary atom site location: structure-invariant direct methods | Absolute structure: Flack (1983), 1687 Friedel pairs |
Secondary atom site location: difference Fourier map | Absolute structure parameter: −0.024 (13) |
C23H35BrO3 | V = 2245.8 (11) Å3 |
Mr = 439.42 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 11.203 (3) Å | µ = 1.85 mm−1 |
b = 11.800 (3) Å | T = 298 K |
c = 16.988 (5) Å | 0.50 × 0.45 × 0.41 mm |
Bruker SMART CCD area-detector diffractometer | 3944 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 1999) | 2383 reflections with I > 2σ(I) |
Tmin = 0.458, Tmax = 0.518 | Rint = 0.093 |
11796 measured reflections |
R[F2 > 2σ(F2)] = 0.047 | H-atom parameters constrained |
wR(F2) = 0.108 | Δρmax = 0.40 e Å−3 |
S = 0.96 | Δρmin = −0.26 e Å−3 |
3944 reflections | Absolute structure: Flack (1983), 1687 Friedel pairs |
245 parameters | Absolute structure parameter: −0.024 (13) |
0 restraints |
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 | ||
Br1 | 0.68536 (6) | 0.37853 (5) | 0.23962 (3) | 0.0740 (3) | |
O1 | 0.8434 (3) | 0.8337 (3) | 0.2930 (2) | 0.0733 (12) | |
O2 | 0.9186 (4) | 0.9167 (3) | 0.3975 (2) | 0.0694 (12) | |
O3 | 0.7310 (4) | 0.2287 (3) | 0.3988 (3) | 0.0794 (13) | |
C1 | 0.7080 (4) | 0.8666 (4) | 0.3967 (2) | 0.0385 (12) | |
C2 | 0.7046 (5) | 0.9117 (4) | 0.4811 (3) | 0.0498 (14) | |
H2A | 0.7466 | 0.9836 | 0.4828 | 0.060* | |
H2B | 0.6221 | 0.9260 | 0.4954 | 0.060* | |
C3 | 0.7588 (5) | 0.8336 (4) | 0.5414 (3) | 0.0541 (15) | |
H3A | 0.7474 | 0.8655 | 0.5935 | 0.065* | |
H3B | 0.8439 | 0.8273 | 0.5320 | 0.065* | |
C4 | 0.7018 (5) | 0.7149 (4) | 0.5382 (2) | 0.0459 (13) | |
H4A | 0.7434 | 0.6656 | 0.5748 | 0.055* | |
H4B | 0.6194 | 0.7203 | 0.5553 | 0.055* | |
C5 | 0.7051 (4) | 0.6609 (3) | 0.4559 (2) | 0.0323 (11) | |
C6 | 0.6208 (4) | 0.5550 (3) | 0.4581 (3) | 0.0320 (11) | |
H6 | 0.5446 | 0.5848 | 0.4774 | 0.038* | |
C7 | 0.6560 (5) | 0.4652 (4) | 0.5190 (3) | 0.0475 (14) | |
H7A | 0.7369 | 0.4404 | 0.5083 | 0.057* | |
H7B | 0.6552 | 0.4995 | 0.5709 | 0.057* | |
C8 | 0.5740 (5) | 0.3617 (4) | 0.5195 (3) | 0.0526 (14) | |
H8A | 0.5003 | 0.3811 | 0.5464 | 0.063* | |
H8B | 0.6121 | 0.3012 | 0.5489 | 0.063* | |
C9 | 0.5444 (5) | 0.3191 (4) | 0.4363 (3) | 0.0486 (14) | |
C10 | 0.6638 (5) | 0.3074 (4) | 0.3954 (3) | 0.0487 (14) | |
C11 | 0.6880 (5) | 0.4191 (4) | 0.3513 (2) | 0.0381 (12) | |
H11 | 0.7664 | 0.4493 | 0.3659 | 0.046* | |
C12 | 0.5894 (4) | 0.5006 (3) | 0.3769 (2) | 0.0307 (11) | |
C13 | 0.5508 (4) | 0.5921 (4) | 0.3191 (3) | 0.0375 (12) | |
H13A | 0.5434 | 0.5588 | 0.2671 | 0.045* | |
H13B | 0.4728 | 0.6201 | 0.3344 | 0.045* | |
C14 | 0.6371 (4) | 0.6909 (4) | 0.3149 (2) | 0.0354 (12) | |
H14A | 0.6073 | 0.7466 | 0.2778 | 0.042* | |
H14B | 0.7139 | 0.6643 | 0.2961 | 0.042* | |
C15 | 0.6524 (4) | 0.7460 (3) | 0.3957 (2) | 0.0318 (11) | |
H15 | 0.5704 | 0.7580 | 0.4140 | 0.038* | |
C16 | 0.4857 (4) | 0.4155 (4) | 0.3910 (3) | 0.0433 (14) | |
H16A | 0.4223 | 0.4500 | 0.4216 | 0.052* | |
H16B | 0.4530 | 0.3888 | 0.3415 | 0.052* | |
C17 | 0.8350 (5) | 0.8739 (4) | 0.3649 (3) | 0.0427 (12) | |
C18 | 0.6337 (5) | 0.9479 (4) | 0.3449 (3) | 0.0606 (17) | |
H18A | 0.5518 | 0.9463 | 0.3616 | 0.091* | |
H18B | 0.6386 | 0.9243 | 0.2909 | 0.091* | |
H18C | 0.6643 | 1.0235 | 0.3499 | 0.091* | |
C19 | 0.8353 (4) | 0.6305 (4) | 0.4370 (3) | 0.0418 (12) | |
H19A | 0.8396 | 0.5977 | 0.3854 | 0.063* | |
H19B | 0.8642 | 0.5770 | 0.4751 | 0.063* | |
H19C | 0.8834 | 0.6977 | 0.4388 | 0.063* | |
C20 | 0.4736 (5) | 0.2087 (4) | 0.4388 (4) | 0.0731 (19) | |
H20A | 0.3994 | 0.2211 | 0.4657 | 0.110* | |
H20B | 0.5189 | 0.1520 | 0.4662 | 0.110* | |
H20C | 0.4580 | 0.1835 | 0.3861 | 0.110* | |
C21 | 0.9562 (6) | 0.8432 (6) | 0.2497 (4) | 0.088 (2) | |
H21 | 1.0143 | 0.8872 | 0.2801 | 0.105* | |
C22 | 1.0009 (6) | 0.7247 (7) | 0.2372 (5) | 0.110 (3) | |
H22A | 1.0197 | 0.6911 | 0.2872 | 0.166* | |
H22B | 1.0712 | 0.7265 | 0.2050 | 0.166* | |
H22C | 0.9403 | 0.6806 | 0.2116 | 0.166* | |
C23 | 0.9293 (9) | 0.9009 (7) | 0.1744 (4) | 0.131 (3) | |
H23A | 0.9020 | 0.9766 | 0.1848 | 0.197* | |
H23B | 0.8682 | 0.8598 | 0.1469 | 0.197* | |
H23C | 1.0001 | 0.9039 | 0.1426 | 0.197* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Br1 | 0.0767 (4) | 0.0953 (5) | 0.0501 (4) | 0.0172 (4) | 0.0068 (3) | −0.0263 (3) |
O1 | 0.068 (3) | 0.097 (3) | 0.055 (2) | −0.043 (2) | 0.011 (2) | −0.0233 (19) |
O2 | 0.047 (3) | 0.091 (3) | 0.070 (3) | −0.024 (2) | −0.014 (2) | −0.016 (2) |
O3 | 0.080 (3) | 0.040 (2) | 0.118 (4) | 0.021 (2) | 0.023 (3) | 0.001 (2) |
C1 | 0.038 (3) | 0.035 (3) | 0.043 (3) | −0.001 (2) | −0.009 (2) | −0.006 (2) |
C2 | 0.049 (4) | 0.041 (3) | 0.059 (3) | −0.005 (2) | −0.006 (3) | −0.017 (2) |
C3 | 0.062 (4) | 0.062 (4) | 0.038 (3) | −0.010 (3) | −0.004 (3) | −0.020 (3) |
C4 | 0.052 (4) | 0.050 (3) | 0.036 (3) | −0.004 (3) | −0.005 (3) | −0.004 (2) |
C5 | 0.028 (3) | 0.038 (3) | 0.031 (2) | 0.006 (2) | −0.005 (2) | −0.0012 (19) |
C6 | 0.028 (3) | 0.033 (3) | 0.035 (3) | 0.009 (2) | 0.004 (2) | 0.002 (2) |
C7 | 0.063 (4) | 0.044 (3) | 0.035 (3) | 0.011 (3) | 0.005 (3) | 0.003 (2) |
C8 | 0.067 (4) | 0.040 (3) | 0.051 (3) | 0.001 (3) | 0.013 (3) | 0.010 (3) |
C9 | 0.053 (4) | 0.033 (3) | 0.060 (4) | −0.012 (3) | 0.017 (3) | −0.004 (3) |
C10 | 0.057 (4) | 0.033 (3) | 0.056 (3) | 0.008 (3) | 0.007 (3) | −0.007 (3) |
C11 | 0.037 (3) | 0.043 (3) | 0.034 (3) | −0.002 (2) | 0.004 (3) | −0.006 (2) |
C12 | 0.028 (3) | 0.027 (3) | 0.038 (3) | −0.001 (2) | 0.004 (2) | −0.002 (2) |
C13 | 0.036 (3) | 0.041 (3) | 0.036 (3) | −0.004 (2) | −0.006 (2) | −0.004 (2) |
C14 | 0.037 (3) | 0.036 (3) | 0.033 (3) | 0.000 (2) | −0.007 (2) | 0.004 (2) |
C15 | 0.024 (3) | 0.033 (3) | 0.037 (3) | −0.002 (2) | −0.008 (2) | −0.007 (2) |
C16 | 0.033 (3) | 0.038 (3) | 0.058 (3) | −0.006 (2) | 0.011 (2) | −0.007 (3) |
C17 | 0.053 (4) | 0.033 (3) | 0.042 (3) | −0.011 (3) | −0.010 (3) | 0.000 (2) |
C18 | 0.063 (4) | 0.040 (3) | 0.079 (4) | 0.004 (3) | −0.030 (3) | 0.007 (3) |
C19 | 0.027 (3) | 0.046 (3) | 0.051 (3) | −0.001 (3) | −0.007 (2) | 0.006 (2) |
C20 | 0.081 (5) | 0.043 (4) | 0.095 (5) | −0.014 (3) | 0.025 (4) | 0.004 (3) |
C21 | 0.072 (4) | 0.121 (6) | 0.070 (5) | −0.053 (4) | 0.033 (4) | −0.027 (5) |
C22 | 0.078 (5) | 0.155 (8) | 0.097 (6) | −0.012 (5) | 0.032 (4) | 0.005 (6) |
C23 | 0.186 (10) | 0.113 (7) | 0.094 (6) | −0.046 (6) | 0.064 (6) | 0.004 (5) |
Br1—C11 | 1.957 (4) | C10—C11 | 1.539 (6) |
O1—C17 | 1.314 (5) | C11—C12 | 1.528 (6) |
O1—C21 | 1.467 (6) | C11—H11 | 0.9800 |
O2—C17 | 1.199 (5) | C12—C13 | 1.522 (6) |
O3—C10 | 1.197 (6) | C12—C16 | 1.554 (6) |
C1—C17 | 1.524 (6) | C13—C14 | 1.515 (6) |
C1—C2 | 1.529 (6) | C13—H13A | 0.9700 |
C1—C18 | 1.546 (6) | C13—H13B | 0.9700 |
C1—C15 | 1.554 (6) | C14—C15 | 1.528 (6) |
C2—C3 | 1.506 (7) | C14—H14A | 0.9700 |
C2—H2A | 0.9700 | C14—H14B | 0.9700 |
C2—H2B | 0.9700 | C15—H15 | 0.9800 |
C3—C4 | 1.541 (6) | C16—H16A | 0.9700 |
C3—H3A | 0.9700 | C16—H16B | 0.9700 |
C3—H3B | 0.9700 | C18—H18A | 0.9600 |
C4—C5 | 1.536 (6) | C18—H18B | 0.9600 |
C4—H4A | 0.9700 | C18—H18C | 0.9600 |
C4—H4B | 0.9700 | C19—H19A | 0.9600 |
C5—C19 | 1.536 (6) | C19—H19B | 0.9600 |
C5—C15 | 1.551 (6) | C19—H19C | 0.9600 |
C5—C6 | 1.567 (6) | C20—H20A | 0.9600 |
C6—C7 | 1.532 (6) | C20—H20B | 0.9600 |
C6—C12 | 1.562 (6) | C20—H20C | 0.9600 |
C6—H6 | 0.9800 | C21—C23 | 1.481 (10) |
C7—C8 | 1.528 (6) | C21—C22 | 1.500 (9) |
C7—H7A | 0.9700 | C21—H21 | 0.9800 |
C7—H7B | 0.9700 | C22—H22A | 0.9600 |
C8—C9 | 1.537 (7) | C22—H22B | 0.9600 |
C8—H8A | 0.9700 | C22—H22C | 0.9600 |
C8—H8B | 0.9700 | C23—H23A | 0.9600 |
C9—C10 | 1.514 (7) | C23—H23B | 0.9600 |
C9—C16 | 1.523 (7) | C23—H23C | 0.9600 |
C9—C20 | 1.526 (7) | ||
C17—O1—C21 | 120.0 (4) | C13—C12—C6 | 110.0 (3) |
C17—C1—C2 | 109.6 (4) | C11—C12—C6 | 110.3 (4) |
C17—C1—C18 | 105.4 (4) | C16—C12—C6 | 107.3 (4) |
C2—C1—C18 | 107.7 (4) | C14—C13—C12 | 113.3 (4) |
C17—C1—C15 | 115.0 (4) | C14—C13—H13A | 108.9 |
C2—C1—C15 | 108.6 (4) | C12—C13—H13A | 108.9 |
C18—C1—C15 | 110.2 (4) | C14—C13—H13B | 108.9 |
C3—C2—C1 | 114.5 (4) | C12—C13—H13B | 108.9 |
C3—C2—H2A | 108.6 | H13A—C13—H13B | 107.7 |
C1—C2—H2A | 108.6 | C13—C14—C15 | 110.9 (4) |
C3—C2—H2B | 108.6 | C13—C14—H14A | 109.4 |
C1—C2—H2B | 108.6 | C15—C14—H14A | 109.4 |
H2A—C2—H2B | 107.6 | C13—C14—H14B | 109.4 |
C2—C3—C4 | 111.4 (4) | C15—C14—H14B | 109.4 |
C2—C3—H3A | 109.3 | H14A—C14—H14B | 108.0 |
C4—C3—H3A | 109.3 | C14—C15—C5 | 111.1 (3) |
C2—C3—H3B | 109.3 | C14—C15—C1 | 116.4 (4) |
C4—C3—H3B | 109.3 | C5—C15—C1 | 115.7 (3) |
H3A—C3—H3B | 108.0 | C14—C15—H15 | 103.9 |
C5—C4—C3 | 113.6 (4) | C5—C15—H15 | 103.9 |
C5—C4—H4A | 108.8 | C1—C15—H15 | 103.9 |
C3—C4—H4A | 108.8 | C9—C16—C12 | 103.8 (4) |
C5—C4—H4B | 108.8 | C9—C16—H16A | 111.0 |
C3—C4—H4B | 108.8 | C12—C16—H16A | 111.0 |
H4A—C4—H4B | 107.7 | C9—C16—H16B | 111.0 |
C4—C5—C19 | 108.0 (4) | C12—C16—H16B | 111.0 |
C4—C5—C15 | 108.8 (3) | H16A—C16—H16B | 109.0 |
C19—C5—C15 | 112.0 (4) | O2—C17—O1 | 121.7 (5) |
C4—C5—C6 | 107.2 (4) | O2—C17—C1 | 126.1 (4) |
C19—C5—C6 | 113.0 (3) | O1—C17—C1 | 112.1 (4) |
C15—C5—C6 | 107.6 (3) | C1—C18—H18A | 109.5 |
C7—C6—C12 | 111.7 (3) | C1—C18—H18B | 109.5 |
C7—C6—C5 | 114.4 (4) | H18A—C18—H18B | 109.5 |
C12—C6—C5 | 116.3 (3) | C1—C18—H18C | 109.5 |
C7—C6—H6 | 104.3 | H18A—C18—H18C | 109.5 |
C12—C6—H6 | 104.3 | H18B—C18—H18C | 109.5 |
C5—C6—H6 | 104.3 | C5—C19—H19A | 109.5 |
C8—C7—C6 | 113.7 (4) | C5—C19—H19B | 109.5 |
C8—C7—H7A | 108.8 | H19A—C19—H19B | 109.5 |
C6—C7—H7A | 108.8 | C5—C19—H19C | 109.5 |
C8—C7—H7B | 108.8 | H19A—C19—H19C | 109.5 |
C6—C7—H7B | 108.8 | H19B—C19—H19C | 109.5 |
H7A—C7—H7B | 107.7 | C9—C20—H20A | 109.5 |
C7—C8—C9 | 112.7 (4) | C9—C20—H20B | 109.5 |
C7—C8—H8A | 109.1 | H20A—C20—H20B | 109.5 |
C9—C8—H8A | 109.1 | C9—C20—H20C | 109.5 |
C7—C8—H8B | 109.1 | H20A—C20—H20C | 109.5 |
C9—C8—H8B | 109.1 | H20B—C20—H20C | 109.5 |
H8A—C8—H8B | 107.8 | O1—C21—C23 | 107.0 (6) |
C10—C9—C16 | 102.5 (4) | O1—C21—C22 | 106.7 (5) |
C10—C9—C20 | 113.2 (4) | C23—C21—C22 | 112.0 (6) |
C16—C9—C20 | 115.3 (5) | O1—C21—H21 | 110.3 |
C10—C9—C8 | 105.2 (4) | C23—C21—H21 | 110.3 |
C16—C9—C8 | 108.3 (4) | C22—C21—H21 | 110.3 |
C20—C9—C8 | 111.5 (5) | C21—C22—H22A | 109.5 |
O3—C10—C9 | 127.2 (5) | C21—C22—H22B | 109.5 |
O3—C10—C11 | 125.2 (5) | H22A—C22—H22B | 109.5 |
C9—C10—C11 | 107.6 (4) | C21—C22—H22C | 109.5 |
C12—C11—C10 | 105.9 (4) | H22A—C22—H22C | 109.5 |
C12—C11—Br1 | 114.7 (3) | H22B—C22—H22C | 109.5 |
C10—C11—Br1 | 105.1 (3) | C21—C23—H23A | 109.5 |
C12—C11—H11 | 110.3 | C21—C23—H23B | 109.5 |
C10—C11—H11 | 110.3 | H23A—C23—H23B | 109.5 |
Br1—C11—H11 | 110.3 | C21—C23—H23C | 109.5 |
C13—C12—C11 | 117.9 (4) | H23A—C23—H23C | 109.5 |
C13—C12—C16 | 110.2 (4) | H23B—C23—H23C | 109.5 |
C11—C12—C16 | 100.2 (3) |
Experimental details
Crystal data | |
Chemical formula | C23H35BrO3 |
Mr | 439.42 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 298 |
a, b, c (Å) | 11.203 (3), 11.800 (3), 16.988 (5) |
V (Å3) | 2245.8 (11) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.85 |
Crystal size (mm) | 0.50 × 0.45 × 0.41 |
Data collection | |
Diffractometer | Bruker SMART CCD area-detector |
Absorption correction | Multi-scan (SADABS; Bruker, 1999) |
Tmin, Tmax | 0.458, 0.518 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 11796, 3944, 2383 |
Rint | 0.093 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.047, 0.108, 0.96 |
No. of reflections | 3944 |
No. of parameters | 245 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.40, −0.26 |
Absolute structure | Flack (1983), 1687 Friedel pairs |
Absolute structure parameter | −0.024 (13) |
Computer programs: SMART (Bruker, 1999), SAINT (Bruker, 1999), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).
Puckering parameters | Ring A | Ring B | Ring C | Ring D |
Q | 0.540 (5) | 0.563 (4) | 0.641 (5) | 0.441 (5) |
θ | 180.0 (5) | 171.9 (4) | 19.3 (4) | |
φ | 314 (67) | 98 (3) | 243.1 (14) | 134.2 (7) |
Ring A atoms C1–C5/C15, B C5–C6/C12–C15, C C6–C9/C12/C16 and D C9–C12/C16. |
Acknowledgements
We are grateful to the China Ministry of Health Foundation for Scientific Research (project No. WKJ2005–2-022) for financial support.
References
Bruker (1999). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Cai, J., Zhou, W., Chen, J. Q., Sun, M. & Ji, M. (2009). J. Chem. Crystallogr. 39, 108–111. Web of Science CSD CrossRef CAS Google Scholar
Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354–1358. CrossRef CAS Web of Science Google Scholar
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Liu, J. C., Kao, P. F., Hsieh, M. H., Chen, Y. J. & Chan, P. (2001). Acta Cardiol. Sin. 17, 133–140. Google Scholar
Mizushina, Y., Akihis, T., Ukiya, M., Hamasaki, Y., Murakami-Nakai, C., Kuriyama, I., Takeuchi, T., Sugawara, F. & Yoshid, H. (2005). Life Sci. 77, 2127–2140. Web of Science CrossRef PubMed CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Shi, H. (2010). Acta Cryst. E66, o154. Web of Science CSD CrossRef IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Wong, K. L., Chan, P., Yang, H. Y., Hsu, F. L., Liu, I. M., Cheng, Y. W. & Cheng, J. T. (2004). Life Sci. 74, 2379–2387. Web of Science CrossRef PubMed CAS Google Scholar
Wu, Y., Yang, J. H., Dai, G. F., Liu, C. J., Tian, G. Q., Ma, W. Y. & Tao, J. C. (2009). Bioorg. Med. Chem. 17, 1464–1473. Web of Science CSD CrossRef PubMed CAS Google Scholar
Xu, D. Y., Li, Y. F., Wang, J. P., Davey, A. K., Zhang, S. J. & Evans, A. M. (2007). Life Sci. 80, 269–274. Web of Science CrossRef PubMed CAS Google Scholar
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.
Isosteviol is a tetracyclic diterpenoid with a beyerane skeleton, which has good pharmacological activity against broad spectrum significant diseases including ischemia-reperfusion injury, hypertension, and cancer (Wong et al., 2004; Liu, et al., 2001; Xu, et al., 2007; Mizushina et al., 2005). The title compound was obtained by esterification and bromination of isosteviol, respectively. The molecule structure of (I) contains a fused four-ring system A/B/C/D (Fig. 1). The A/B ring and B/C junction are trans-fused, and C/D is cis-fused. Rings A and B adopt chair conformations and ring C is in a distorted chair conformation, with puckering amplitude Q = 0.641 (5) Å, θ= 19.3 (4)° and φ= 243.1 (14)° (Cremer & Pople, 1975). The distortion may be attributed to the narrowing of the C9—C16—C12 bond angle to 103.8 (4)°. The five-membered ring D adopts an envelope conformation with atom C16 displaced from the C9/C10/C11/C12 plane by 0.281 (5) Å. The C17—C1—C2—C3 torsion angle of -73.8 (5)° describes the β-orientation of the isopropyl ester group with respect to the ent-kaurane nucleus.