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Acta Cryst. (2009). E65, o1540    [ doi:10.1107/S1600536809020960 ]

A 3,5-dinitrobenzoyl derivative of a stereoisomer of glycerol menthonide

A. Kiessling, C. Campana and M. E. Kastner

Abstract top

The title compound, [(2S,5R,6S,9R)-6-isopropyl-9-methyl-1,4-dioxaspiro[4.5]dec-2-yl]methyl 3,5-dinitrobenzoate, C20H26N2O8, was synthesized as part of a study of three-carbon stereochemical systems. The crystallographic assignment of the absolute stereochemistry is consistent with having started with (-)-menthone, the acetal carbon is R and the secondary alcohol is S. This brings the dinitrobenzoate into approximately the same plane as the menthyl ring and anti to the isopropyl group. Close intermolecular C=O...NO2 contacts between neighboring molecules [2.8341 (16) Å] contribute to the packing arrangement. The structure was refined as a pseudo-merohedral twin (monoclinic space group P21 emulating the orthorhombic space group C2221). Application of the twin law 100, 0\overline{1}0, \overline{1}0\overline{1} gave a 2:1 ratio of twin moieties [refined BASF value = 0.3790 (7)].

Comment top

The title structure was synthesized as part of a study of 3-carbon stereochemical moieties, specifically tri-substituted glycerol. Here menthone serves as a chiral auxiliary, freezing two carbons into a specific stereochemistry and influencing the stereochemistry of the third owing to the steric bulk of the menthone.

The starting material, glycerol menthonide, was originally prepared as an additive to spearmint gum by reaction of menthone with glycerol under acid catalysis. (Greenberg, 1999) No further chemical analysis of the menthonide has been reported in the literature.

Glycerol menthonide exists in as many as six isomers which are difficult to separate. However, conversion of the hydroxy group to an ester by reaction with 4-bromobenzoyl chloride yields a mixture of esters that are separable by flash chromatography.

One stereochemically pure ester was hydrolyzed back to the free alcohol then converted to the 3,5-dinitrobenzoate. The crystallographic assignment of the absolute stereochemistry is consistent with having started with (-)-menthone, and provides the stereochemistry of the acetal carbon and the esterified secondary alcohol of the glycerol chain. Specifically, the acetal carbon, C5, is R and the secondary alcohol, C2, is S. This brings the dinitrobenzoate into approximately the same plane as the menthyl ring and anti to the isopropyl group.

There is a close contact between the carbonyl oxygen, O25, and one of the nitro groups on a 21 screw-related molecule, specifically N28 in the molecule at (1 - x, -0.5, 2 - z). The orientation of the carbonyl group is nearly perpendicular to the plane of the nitro group and the O25 ··· N28 distance is 2.8341 (16) Å. A search of the Cambridge Structural Database (Allen, 2002) for intermolecular C=O ··· NO2-benzene groups found 360 observations for C=O ··· NO2 distances of 3.07 or less. Of these, only seventeen observations were shorter than that reported here, and each of these had a similar perpendicular orientation. The simplest structure in this set is that of 3-nitrophthalic acid (Glidewell et al., 2003) wherein the C=O ··· NO2 distance was reported as 2.807 (2) Å, which the authors attributed to the electrostatic interaction between the partially negative oxygen of the carbonyl and the partially positive nitrogen of the nitro group and analogous to the short intermolecular C=O ··· C=O contacts frequently found between carbonyl groups.

In a study (Allen, et al., 1998) of these intermolecular C=O ··· C=O interactions based on a combination of a detailed analysis of structures from the Cambridge Structural Database as well as ab initio molecular-orbital calculations the authors conclude that, although these intermolecular forces are only a fraction of that of hydrogen bonds, they are significant contributors to the stabilization of the solid state structures. It appears a similar argument could be made for C=O ··· NO2 interactions.

Related literature top

For the synthesis of glycerol menthonide, see: Greenberg (1999). For the synthesis and NMR spectra of the title compound, see: Kiessling et al. (2009). Glidewell et al. (2003) report a releted structure with a very short C=O ··· NO2 distance. Allen et al. (1998) report on intermolecular C=O ··· C=O interactions. For a description of the Cambridge Crystallographic Database, see: Allen (2002).

Experimental top

Details on the synthesis of the title compound and its NMR spectra have been published separately. (Kiessling et al., 2009)

Refinement top

The structure was refined as a pseudo-merohedral twin (Monoclinic space group P21 emulating the orthorhombic space group C2221). Application of the twin law 1 0 0, 0 -1 0, -1 0 -1 gave a 2:1 ratio of twin moieties (refined BASF value 0.3790 (7)).

Hydrogen positions were calculated and refined using a riding model using the following C—H distances: methyne 1.000 Å, methylene 0.990 Å, methyl 0.980Å and aromatic 0.950 Å. The isotropic U values for the H atoms were set at 50% above that of bonded carbon for methyl H atoms and 20% above that of the bonded carbon for all other H atoms.

Computing details top

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The title compound, C20H26N2O8, showing 50% probability displacement ellipsoids and the atom-numbering scheme.
[Figure 2] Fig. 2. A packing diagram of the title compound. The close intermolecular C═O···NO2 contact is shown by the dotted lines.
[(2S,5R,6S,9R)-6-isopropyl-9-methyl-1,4- dioxaspiro[4.5]dec-2-yl]methyl 3,5-dinitrobenzoate top
Crystal data top
C20H26N2O8F(000) = 448
Mr = 422.43Dx = 1.323 Mg m−3
Monoclinic, P21Melting point: 368 K
Hall symbol: P 2ybCu Kα radiation, λ = 1.54178 Å
a = 9.4396 (5) ÅCell parameters from 9947 reflections
b = 5.8825 (3) Åθ = 2.3–68.2°
c = 19.6719 (10) ŵ = 0.87 mm−1
β = 103.923 (3)°T = 100 K
V = 1060.26 (9) Å3Needle, colourless
Z = 20.38 × 0.09 × 0.02 mm
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer		3275 independent reflections
Radiation source: fine-focus sealed tube3254 reflections with I > 2σ(I)
graphiteRint = 0.025
φ and ω scansθmax = 68.2°, θmin = 2.3°
Absorption correction: multi-scan
(SADABS; Bruker, 2008)		h = −11→11
Tmin = 0.602, Tmax = 0.977k = −6→5
16481 measured reflectionsl = −23→23
Refinement top
Refinement on F2Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.018 w = 1/[σ2(Fo2) + (0.0245P)2 + 0.0832P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.045(Δ/σ)max = 0.001
S = 1.06Δρmax = 0.10 e Å−3
3275 reflectionsΔρmin = −0.11 e Å−3
276 parametersExtinction correction: SHELXTL (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
1 restraintExtinction coefficient: 0.0009 (2)
Primary atom site location: structure-invariant direct methodsAbsolute structure: Flack (1983), 1131 Friedel pairs
Secondary atom site location: difference Fourier mapFlack parameter: 0.03 (13)
Crystal data top
C20H26N2O8V = 1060.26 (9) Å3
Mr = 422.43Z = 2
Monoclinic, P21Cu Kα radiation
a = 9.4396 (5) ŵ = 0.87 mm−1
b = 5.8825 (3) ÅT = 100 K
c = 19.6719 (10) Å0.38 × 0.09 × 0.02 mm
β = 103.923 (3)°
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer		3275 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2008)		3254 reflections with I > 2σ(I)
Tmin = 0.602, Tmax = 0.977Rint = 0.025
16481 measured reflectionsθmax = 68.2°
Refinement top
R[F2 > 2σ(F2)] = 0.018H-atom parameters constrained
wR(F2) = 0.045Δρmax = 0.10 e Å−3
S = 1.06Δρmin = −0.11 e Å−3
3275 reflectionsAbsolute structure: Flack (1983), 1131 Friedel pairs
276 parametersFlack parameter: 0.03 (13)
1 restraint
Special details top

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 structure was refined as a pseudo-merohedral twin (monoclinic space group P21 emulating orthorhombic space group C2221); Twin law 1 0 0 0 - 1 0 - 1 0 - 1; Refined ratio (BASF) 0.3790 (7).

Hydrogen positions were calculated and refined using a riding model using the following C—H distances: methyne 1.000 Å, methylene 0.990 Å, methyl 0.980Å and aromatic 0.950 Å. The isotropic U values for the H atoms were set at 50% above that of bonded carbon for methyl H atoms and 20% above that of the bonded carbon for all other H atoms.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.72662 (12)−0.12929 (19)0.71101 (5)0.0258 (3)
C20.81610 (17)−0.1291 (3)0.78046 (7)0.0227 (3)
H20.9171−0.17830.77960.027*
C30.81810 (17)0.1200 (3)0.80073 (8)0.0222 (3)
H3A0.73290.15890.81960.027*
H3B0.90880.15910.83590.027*
O40.81137 (12)0.23300 (19)0.73591 (5)0.0227 (2)
C50.72348 (19)0.0946 (3)0.68212 (8)0.0232 (3)
C60.78923 (18)0.0943 (3)0.61799 (8)0.0266 (4)
H60.7245−0.00530.58240.032*
C70.7763 (2)0.3330 (3)0.58613 (8)0.0329 (4)
H7A0.83590.44000.62020.039*
H7B0.81540.33190.54370.039*
C80.6194 (2)0.4149 (4)0.56676 (8)0.0365 (4)
H8A0.56190.31660.52930.044*
H8B0.61630.57170.54820.044*
C90.54978 (19)0.4117 (3)0.62943 (8)0.0308 (4)
H90.60410.52230.66490.037*
C100.56642 (18)0.1768 (3)0.66303 (8)0.0270 (4)
H10A0.52890.18110.70590.032*
H10B0.50630.06700.63020.032*
C110.3900 (2)0.4850 (4)0.60923 (11)0.0461 (5)
H11A0.33470.38130.57360.069*
H11B0.38310.64000.59040.069*
H11C0.34970.48090.65070.069*
C120.9428 (2)−0.0117 (4)0.63175 (9)0.0344 (4)
H120.9459−0.14140.66490.041*
C130.9717 (2)−0.1084 (4)0.56378 (9)0.0400 (5)
H13A0.96930.01520.53010.060*
H13B0.8964−0.22060.54390.060*
H13C1.0678−0.18140.57400.060*
C141.0663 (2)0.1510 (5)0.66460 (13)0.0633 (8)
H14A1.15820.06640.67820.095*
H14B1.04520.22220.70610.095*
H14C1.07480.26870.63060.095*
C150.75391 (17)−0.2914 (3)0.82456 (8)0.0241 (3)
H15A0.7341−0.44030.80070.029*
H15B0.8241−0.31480.87030.029*
O160.61928 (12)−0.19409 (19)0.83493 (5)0.0219 (3)
C170.55649 (16)−0.3039 (3)0.87874 (7)0.0204 (3)
C180.43170 (16)−0.1728 (3)0.89389 (7)0.0195 (3)
C190.36462 (15)−0.2611 (3)0.94374 (7)0.0207 (3)
H190.3984−0.39890.96730.025*
C200.24814 (16)−0.1456 (3)0.95844 (7)0.0196 (3)
C210.19642 (16)0.0567 (3)0.92634 (7)0.0197 (3)
H210.11670.13500.93730.024*
C220.26696 (16)0.1397 (3)0.87730 (8)0.0203 (3)
C230.38314 (16)0.0311 (3)0.86020 (8)0.0196 (3)
H230.42880.09360.82640.024*
O240.59532 (12)−0.4860 (2)0.90476 (6)0.0267 (3)
N250.21586 (14)0.3563 (2)0.84164 (6)0.0219 (3)
O260.28039 (12)0.4291 (2)0.79908 (5)0.0270 (3)
O270.11232 (11)0.4517 (2)0.85721 (6)0.0275 (3)
N280.17654 (13)−0.2454 (3)1.01017 (6)0.0222 (3)
O290.07569 (12)−0.1400 (2)1.02463 (6)0.0299 (3)
O300.22049 (12)−0.4300 (2)1.03556 (6)0.0271 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0394 (6)0.0178 (6)0.0215 (5)−0.0057 (5)0.0101 (5)−0.0007 (4)
C20.0236 (7)0.0238 (9)0.0229 (7)0.0038 (7)0.0097 (6)0.0018 (7)
C30.0224 (7)0.0251 (10)0.0197 (7)−0.0025 (7)0.0061 (6)−0.0017 (7)
O40.0302 (5)0.0196 (6)0.0189 (5)−0.0046 (5)0.0068 (4)−0.0012 (5)
C50.0325 (8)0.0158 (9)0.0218 (7)−0.0054 (7)0.0075 (7)−0.0010 (6)
C60.0348 (9)0.0263 (10)0.0196 (7)−0.0092 (8)0.0083 (7)−0.0040 (7)
C70.0457 (11)0.0308 (11)0.0237 (7)−0.0144 (8)0.0114 (7)0.0002 (8)
C80.0484 (11)0.0313 (11)0.0249 (8)−0.0089 (9)−0.0011 (7)0.0060 (7)
C90.0340 (9)0.0238 (11)0.0299 (8)−0.0050 (8)−0.0013 (7)0.0004 (7)
C100.0279 (8)0.0261 (10)0.0266 (7)−0.0081 (7)0.0057 (6)−0.0018 (7)
C110.0405 (11)0.0406 (14)0.0503 (11)0.0012 (10)−0.0023 (9)0.0048 (10)
C120.0388 (10)0.0405 (12)0.0272 (8)−0.0038 (9)0.0144 (8)−0.0053 (8)
C130.0560 (12)0.0388 (12)0.0327 (8)−0.0020 (10)0.0253 (9)0.0000 (8)
C140.0360 (11)0.093 (2)0.0638 (13)−0.0085 (12)0.0177 (10)−0.0370 (15)
C150.0248 (8)0.0232 (10)0.0266 (7)0.0072 (7)0.0110 (6)0.0023 (7)
O160.0232 (5)0.0213 (7)0.0236 (5)0.0020 (4)0.0102 (4)0.0035 (5)
C170.0229 (7)0.0205 (9)0.0169 (6)−0.0020 (6)0.0034 (6)−0.0026 (6)
C180.0196 (7)0.0211 (9)0.0172 (6)−0.0025 (6)0.0031 (6)−0.0007 (6)
C190.0204 (8)0.0217 (9)0.0181 (6)−0.0002 (7)0.0007 (6)0.0010 (6)
C200.0200 (7)0.0222 (9)0.0163 (6)−0.0051 (7)0.0036 (5)−0.0024 (6)
C210.0162 (7)0.0218 (9)0.0208 (7)−0.0004 (6)0.0037 (5)−0.0041 (6)
C220.0203 (7)0.0193 (9)0.0198 (6)−0.0037 (6)0.0019 (6)−0.0015 (6)
C230.0206 (7)0.0202 (9)0.0184 (7)−0.0032 (6)0.0052 (6)−0.0010 (6)
O240.0283 (6)0.0241 (7)0.0291 (5)0.0049 (5)0.0100 (5)0.0089 (5)
N250.0209 (6)0.0193 (8)0.0236 (6)−0.0027 (6)0.0017 (5)−0.0011 (6)
O260.0296 (6)0.0245 (7)0.0277 (5)−0.0002 (5)0.0083 (5)0.0060 (5)
O270.0217 (5)0.0223 (7)0.0379 (6)0.0024 (5)0.0060 (5)0.0005 (5)
N280.0194 (6)0.0283 (9)0.0186 (6)−0.0040 (6)0.0043 (5)−0.0008 (6)
O290.0245 (6)0.0357 (7)0.0328 (5)0.0008 (6)0.0137 (5)0.0043 (6)
O300.0278 (6)0.0276 (7)0.0263 (5)−0.0007 (5)0.0074 (5)0.0068 (5)
Geometric parameters (Å, °) top
O1—C21.4230 (17)C12—C131.537 (2)
O1—C51.432 (2)C12—H121.0000
C2—C151.501 (2)C13—H13A0.9800
C2—C31.518 (2)C13—H13B0.9800
C2—H21.0000C13—H13C0.9800
C3—O41.4259 (18)C14—H14A0.9800
C3—H3A0.9900C14—H14B0.9800
C3—H3B0.9900C14—H14C0.9800
O4—C51.4310 (19)C15—O161.4523 (18)
C5—C101.518 (2)C15—H15A0.9900
C5—C61.534 (2)C15—H15B0.9900
C6—C71.531 (3)O16—C171.3257 (19)
C6—C121.541 (2)C17—O241.206 (2)
C6—H61.0000C17—C181.497 (2)
C7—C81.517 (3)C18—C191.390 (2)
C7—H7A0.9900C18—C231.393 (2)
C7—H7B0.9900C19—C201.381 (2)
C8—C91.530 (2)C19—H190.9500
C8—H8A0.9900C20—C211.380 (2)
C8—H8B0.9900C20—N281.4726 (19)
C9—C101.523 (3)C21—C221.386 (2)
C9—C111.526 (3)C21—H210.9500
C9—H91.0000C22—C231.379 (2)
C10—H10A0.9900C22—N251.478 (2)
C10—H10B0.9900C23—H230.9500
C11—H11A0.9800N25—O261.2253 (17)
C11—H11B0.9800N25—O271.2280 (17)
C11—H11C0.9800N28—O301.2254 (18)
C12—C141.526 (3)N28—O291.2256 (18)
C2—O1—C5109.35 (12)H11A—C11—H11C109.5
O1—C2—C15109.28 (13)H11B—C11—H11C109.5
O1—C2—C3102.70 (13)C14—C12—C13108.84 (16)
C15—C2—C3116.37 (13)C14—C12—C6114.26 (18)
O1—C2—H2109.4C13—C12—C6110.70 (15)
C15—C2—H2109.4C14—C12—H12107.6
C3—C2—H2109.4C13—C12—H12107.6
O4—C3—C2102.72 (12)C6—C12—H12107.6
O4—C3—H3A111.2C12—C13—H13A109.5
C2—C3—H3A111.2C12—C13—H13B109.5
O4—C3—H3B111.2H13A—C13—H13B109.5
C2—C3—H3B111.2C12—C13—H13C109.5
H3A—C3—H3B109.1H13A—C13—H13C109.5
C3—O4—C5106.81 (11)H13B—C13—H13C109.5
O4—C5—O1106.07 (11)C12—C14—H14A109.5
O4—C5—C10111.08 (13)C12—C14—H14B109.5
O1—C5—C10108.47 (14)H14A—C14—H14B109.5
O4—C5—C6109.35 (13)C12—C14—H14C109.5
O1—C5—C6110.57 (14)H14A—C14—H14C109.5
C10—C5—C6111.17 (13)H14B—C14—H14C109.5
C7—C6—C5109.12 (14)O16—C15—C2107.91 (13)
C7—C6—C12114.98 (15)O16—C15—H15A110.1
C5—C6—C12113.93 (14)C2—C15—H15A110.1
C7—C6—H6106.0O16—C15—H15B110.1
C5—C6—H6106.0C2—C15—H15B110.1
C12—C6—H6106.0H15A—C15—H15B108.4
C8—C7—C6111.77 (15)C17—O16—C15116.25 (13)
C8—C7—H7A109.3O24—C17—O16124.84 (15)
C6—C7—H7A109.3O24—C17—C18123.15 (14)
C8—C7—H7B109.3O16—C17—C18112.00 (14)
C6—C7—H7B109.3C19—C18—C23120.27 (14)
H7A—C7—H7B107.9C19—C18—C17117.49 (15)
C7—C8—C9112.11 (14)C23—C18—C17122.24 (13)
C7—C8—H8A109.2C20—C19—C18118.97 (15)
C9—C8—H8A109.2C20—C19—H19120.5
C7—C8—H8B109.2C18—C19—H19120.5
C9—C8—H8B109.2C21—C20—C19122.72 (14)
H8A—C8—H8B107.9C21—C20—N28119.29 (14)
C10—C9—C11111.20 (15)C19—C20—N28117.99 (15)
C10—C9—C8109.96 (15)C20—C21—C22116.46 (14)
C11—C9—C8112.06 (15)C20—C21—H21121.8
C10—C9—H9107.8C22—C21—H21121.8
C11—C9—H9107.8C23—C22—C21123.38 (15)
C8—C9—H9107.8C23—C22—N25118.12 (13)
C5—C10—C9112.88 (14)C21—C22—N25118.50 (13)
C5—C10—H10A109.0C22—C23—C18118.20 (14)
C9—C10—H10A109.0C22—C23—H23120.9
C5—C10—H10B109.0C18—C23—H23120.9
C9—C10—H10B109.0O26—N25—O27124.54 (14)
H10A—C10—H10B107.8O26—N25—C22117.82 (13)
C9—C11—H11A109.5O27—N25—C22117.64 (12)
C9—C11—H11B109.5O30—N28—O29124.03 (13)
H11A—C11—H11B109.5O30—N28—C20117.93 (13)
C9—C11—H11C109.5O29—N28—C20118.03 (14)
C5—O1—C2—C15145.19 (13)C5—C6—C12—C13153.37 (16)
C5—O1—C2—C321.05 (15)O1—C2—C15—O16−70.24 (16)
O1—C2—C3—O4−33.31 (15)C3—C2—C15—O1645.44 (18)
C15—C2—C3—O4−152.61 (12)C2—C15—O16—C17−173.43 (12)
C2—C3—O4—C533.85 (16)C15—O16—C17—O24−7.2 (2)
C3—O4—C5—O1−21.48 (16)C15—O16—C17—C18171.59 (12)
C3—O4—C5—C1096.20 (14)O24—C17—C18—C194.1 (2)
C3—O4—C5—C6−140.74 (14)O16—C17—C18—C19−174.70 (13)
C2—O1—C5—O4−0.87 (16)O24—C17—C18—C23−176.18 (15)
C2—O1—C5—C10−120.27 (13)O16—C17—C18—C235.01 (19)
C2—O1—C5—C6117.59 (14)C23—C18—C19—C201.0 (2)
O4—C5—C6—C7−66.69 (17)C17—C18—C19—C20−179.32 (13)
O1—C5—C6—C7176.87 (13)C18—C19—C20—C21−1.0 (2)
C10—C5—C6—C756.32 (18)C18—C19—C20—N28178.53 (13)
O4—C5—C6—C1263.30 (19)C19—C20—C21—C220.6 (2)
O1—C5—C6—C12−53.14 (19)N28—C20—C21—C22−178.93 (13)
C10—C5—C6—C12−173.69 (15)C20—C21—C22—C23−0.1 (2)
C5—C6—C7—C8−56.89 (18)C20—C21—C22—N25−179.81 (12)
C12—C6—C7—C8173.69 (14)C21—C22—C23—C180.2 (2)
C6—C7—C8—C956.6 (2)N25—C22—C23—C18179.83 (13)
C7—C8—C9—C10−53.50 (19)C19—C18—C23—C22−0.6 (2)
C7—C8—C9—C11−177.71 (18)C17—C18—C23—C22179.73 (14)
O4—C5—C10—C965.68 (16)C23—C22—N25—O26−0.60 (19)
O1—C5—C10—C9−178.11 (12)C21—C22—N25—O26179.08 (14)
C6—C5—C10—C9−56.33 (18)C23—C22—N25—O27179.99 (13)
C11—C9—C10—C5178.43 (15)C21—C22—N25—O27−0.33 (19)
C8—C9—C10—C553.72 (17)C21—C20—N28—O30176.82 (13)
C7—C6—C12—C1443.7 (2)C19—C20—N28—O30−2.68 (19)
C5—C6—C12—C14−83.3 (2)C21—C20—N28—O29−2.41 (19)
C7—C6—C12—C13−79.62 (19)C19—C20—N28—O29178.08 (13)
Acknowledgements top

We would like to thank the Mansfield University Foundation for supporting this research.

references
References top

Allen, F. H. (2002). Acta Cryst. B58, 380–388.

Allen, F. H., Baalham, C. A., Lommerse, J. P. M. & Raithby, P. R. (1998). Acta Cryst. B54, 320–329.

Bruker (2008). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Winsonsin, USA.

Flack, H. D. (1983). Acta Cryst. A39, 876–881.

Glidewell, C., Low, J. N., Skakle, J. M. S. & Wardell, J. L. (2003). Acta Cryst. C59, o144–o146.

Greenberg, M. (1999). US Patent No. 5 977 166.

Kiessling, A., Ganong, C. & Johnson, A. (2009). Am. J. Undergrad. Res. 8, 1–6.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.