organic compounds
2,6-Dimethyl-4-oxo-3-oxatricyclo[5.2.1.02,6]decane-1-carboxamide
aNational Taras Shevchenko University, Department of Chemistry, Volodymyrska str. 64, 01033 Kyiv, Ukraine
*Correspondence e-mail: 417lab@gmail.com
In the title compound, C12H17NO3, which was synthesized by Wagner–Meerwein rearrangement of the N-nitroimine, the ring-junction C—C bond length is comparatively long [1.573 (2) Å] due to a steric repulsion between the methyl groups at these atoms, which also leads to an increase in the C—C—C angles along this C4 chain [118.10 (13) and 115.04 (15) °, respectively]. In the crystal, N—H⋯O—C and N—H⋯O=C hydrogen bonds are formed between the amide group and the two O-atom acceptors of the lactone group, forming a chain along [001].
Related literature
For applications of nitroimines and their derivatives in organic synthesis, see: Squire et al. (2002); Bulman Page et al. (2000); Lalk et al. (1999), as organocatalysts, see: Parrott, et al. (2008) and in medicinal chemistry, see: Ranise et al. (1990); Bondavalli et al. (1987). For bond angles in related structures, see: Noe et al. (1996); Knollmuller et al. (1998).
Experimental
Crystal data
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Data collection: APEX2 (Bruker, 2007); cell SAINT (Bruker, 2007); 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.
Supporting information
https://doi.org/10.1107/S1600536813017248/qm2095sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536813017248/qm2095Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S1600536813017248/qm2095Isup3.cml
The synthesis of the nitroimine (I) (Fig. 2) was carried out as follows. A solution of compound I (1.00 g, 4.16 mmol) in methanol (10 ml) was added to a mixture of acetone cyanohydrin 2 mmol (0.708 g) and potassium hydroxide 1.5 mmol (0.35 g) in distilled water. The resulting mixture was stirred and refluxed for 20 min. After cooling in ice an excess of 3 N aqueous hydrochloric acid was added over 5 min with vigorous stirring. Almost immediate precipitation of carboxamide was accompanied by gas (N2O) evolution. The amide was filtered off, washed with distilled water (2x10 mL), dried in a vacuum desiccator overnight and recrystallized from absolute 2-propanol. Yield: 0.86 g 93%; m.p.: 253 °C. 1H NMR (400 MHz, [D6]DMSO, TMS, δ): 1.201 (s, 3 H), 1.516 (s, 3 H), 1.531–1.577 (m, 1 H), 1.630–1.95 (d, J=11.1Hz, 1H), 1.693–1.794 (m, 3 H), 1.952 (d, J=11.1, 1 H), 2.065 (bs, 1 H), 2.601 (s, 2 H); 13C{1H} NMR (100.70 MHz, [D6]DMSO, TMS, δ): 16.55, 20.76, 24.99, 28.53, 37.35, 44.82, 48.14, 49.56, 62.19, 97.18, 177.35,178.65; (KBr plates, cm -1): 3421.23, 3157.94, 1755.23, 1678.33.
Amide H-atoms were located in a difference-Fourier synthesis and both positional and displacement parameters were allowed to refine. Other hydrogen atoms were positioned geometrically, with C—H = 0.96–0.98 Å and were allowed to ride on their parent atoms, with Uiso(H) = 1.2Ueq(methine or methylene C) or 1.5Ueq(methyl C). In the absence of a suitable heavy atom, the
of the title compound could not be determined (1146 Friedel pairs).Nitroimines and their derivatives have found a numerous applications in organic synthesis (Squire et al., 2002; Bulman Page et al., 2000; Lalk et al., 1999), as organocatalysis (Parrott, R. W. et al., 2008) and in medicinal chemistry (Ranise et al., 1990; Bondavalli, et al., 1987). Herein, we report synthesis and
of the title compound (II), the novel 3,7-dimethyl-3-oxohexahydro-4,7-methano-2-benzofuran-4(1H)-carboxamide , C12H17NO3 (Fig. 1)obtained via selective Wagner-Meerwein type rearrangement of potassium cyanide adducts of 1,7-dimethyl-2-(nitroimino)bicyclo[2.2.1]hept-7-ylacetic acid (I) (see Fig. 2).In the structure of (II) (Fig. 1), angle deviations at Csp3 atoms range from 94.22 to 118.10 (16) °. Thus the C1—C7—C4 angle as in other previously reported compounds has a reduced value of 94.22 (12) ° (Noe et al., 1996; Knollmuller et al., 1998). Most bond distances for compound (I) were in the expected range however, the C5-C6 bond length is 1.573 (2) Å, which is apparently due to steric repulsion between the methyl groups on these atoms, this also leads to an increase in the angles C5C6C10 and C6C5C9 to 118.10 (13) and 115.04 (15) °, respectively. It is interesting to note that the bond O4—C6 is slightly longer (1.4714 (16) Å) and O4—C12 shorter (1.335 (2) Å) compared with the values previously found (average 1.45 and 1.36 Å, respectively). Intermolecular hydrogen bonds are formed through N—H···O—C and N—H···O═C between the amide and two O-atom acceptors of lactone group. (Table 1).
For applications of nitroimines and their derivatives in organic synthesis, see: Squire et al. (2002); Bulman Page et al. (2000); Lalk et al. (1999), as organocatalysts, see: Parrott, et al. (2008) and in medicinal chemistry, see: Ranise et al. (1990); Bondavalli et al. (1987). For bond angles in related structures, see: Noe et al. (1996); Knollmuller et al. (1998).
For related literature, see: Bondavalli et al. (1987).
Data collection: APEX2 (Bruker, 2007); cell
SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); 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).Fig. 1. The molecular structure and atom nunbering scheme for the title compound, showing 30% probability displacement ellipsoids. | |
Fig. 2. The synthetic route to the title compound (II). |
C12H17NO3 | F(000) = 240 |
Mr = 223.27 | Dx = 1.332 Mg m−3 |
Triclinic, P1 | Melting point: 531 K |
a = 7.0659 (3) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 7.8206 (3) Å | Cell parameters from 8729 reflections |
c = 10.4595 (3) Å | θ = 2.0–27.0° |
α = 79.667 (2)° | µ = 0.10 mm−1 |
β = 80.471 (2)° | T = 296 K |
γ = 81.579 (2)° | Block, colourless |
V = 556.69 (4) Å3 | 0.25 × 0.2 × 0.15 mm |
Z = 2 |
Bruker SMART APEXII CCD area-detector diffractometer | 2405 independent reflections |
Radiation source: fine-focus sealed tube | 1754 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.037 |
ω scans | θmax = 27.0°, θmin = 2.0° |
Absorption correction: multi-scan (SADABS; Bruker, 2008) | h = −9→6 |
Tmin = 0.977, Tmax = 0.986 | k = −9→9 |
8729 measured reflections | l = −13→12 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.044 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.141 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.92 | w = 1/[σ2(Fo2) + (0.1P)2] where P = (Fo2 + 2Fc2)/3 |
2405 reflections | (Δ/σ)max = 0.001 |
213 parameters | Δρmax = 0.17 e Å−3 |
0 restraints | Δρmin = −0.21 e Å−3 |
C12H17NO3 | γ = 81.579 (2)° |
Mr = 223.27 | V = 556.69 (4) Å3 |
Triclinic, P1 | Z = 2 |
a = 7.0659 (3) Å | Mo Kα radiation |
b = 7.8206 (3) Å | µ = 0.10 mm−1 |
c = 10.4595 (3) Å | T = 296 K |
α = 79.667 (2)° | 0.25 × 0.2 × 0.15 mm |
β = 80.471 (2)° |
Bruker SMART APEXII CCD area-detector diffractometer | 2405 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2008) | 1754 reflections with I > 2σ(I) |
Tmin = 0.977, Tmax = 0.986 | Rint = 0.037 |
8729 measured reflections |
R[F2 > 2σ(F2)] = 0.044 | 0 restraints |
wR(F2) = 0.141 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.92 | Δρmax = 0.17 e Å−3 |
2405 reflections | Δρmin = −0.21 e Å−3 |
213 parameters |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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 | ||
N1 | 0.3999 (2) | 0.54171 (18) | 0.34083 (15) | 0.0369 (4) | |
O2 | 0.33949 (19) | 0.33578 (16) | 0.51638 (12) | 0.0494 (4) | |
O3 | 0.5612 (2) | 0.31087 (19) | −0.04693 (13) | 0.0603 (4) | |
O4 | 0.45280 (15) | 0.25378 (14) | 0.16493 (10) | 0.0347 (3) | |
C1 | 0.1850 (2) | 0.32889 (19) | 0.33196 (14) | 0.0273 (4) | |
C2 | 0.0143 (2) | 0.2540 (2) | 0.42730 (17) | 0.0375 (4) | |
C3 | −0.1362 (3) | 0.2492 (3) | 0.3377 (2) | 0.0484 (5) | |
C4 | −0.0303 (2) | 0.3074 (2) | 0.20074 (19) | 0.0429 (4) | |
C5 | 0.1373 (2) | 0.1653 (2) | 0.16319 (15) | 0.0358 (4) | |
C6 | 0.2885 (2) | 0.18268 (18) | 0.25359 (14) | 0.0269 (3) | |
C7 | 0.0779 (3) | 0.4509 (2) | 0.22716 (19) | 0.0381 (4) | |
C8 | 0.3163 (2) | 0.4028 (2) | 0.40296 (15) | 0.0298 (4) | |
C9 | 0.0736 (4) | −0.0173 (3) | 0.1799 (2) | 0.0540 (5) | |
C10 | 0.3770 (3) | 0.0174 (2) | 0.33196 (19) | 0.0393 (4) | |
C11 | 0.2432 (3) | 0.2168 (3) | 0.02428 (19) | 0.0523 (5) | |
C12 | 0.4339 (3) | 0.2662 (2) | 0.03857 (16) | 0.0404 (4) | |
H4 | −0.113 (3) | 0.340 (3) | 0.133 (2) | 0.060 (6)* | |
H21 | 0.057 (2) | 0.134 (2) | 0.4786 (17) | 0.039 (5)* | |
H22 | −0.035 (3) | 0.332 (2) | 0.4956 (19) | 0.048 (5)* | |
H31 | −0.255 (3) | 0.336 (3) | 0.358 (2) | 0.064 (6)* | |
H32 | −0.182 (3) | 0.137 (3) | 0.347 (2) | 0.059 (6)* | |
H71 | −0.003 (3) | 0.545 (3) | 0.2658 (18) | 0.051 (5)* | |
H72 | 0.165 (2) | 0.501 (2) | 0.1515 (17) | 0.035 (5)* | |
H91 | 0.027 (3) | −0.063 (3) | 0.274 (2) | 0.063 (6)* | |
H92 | −0.029 (4) | −0.010 (4) | 0.128 (3) | 0.090 (8)* | |
H93 | 0.177 (3) | −0.102 (3) | 0.143 (2) | 0.068 (7)* | |
H101 | 0.470 (4) | 0.049 (3) | 0.379 (2) | 0.070 (7)* | |
H102 | 0.277 (3) | −0.046 (3) | 0.391 (2) | 0.055 (6)* | |
H103 | 0.446 (3) | −0.060 (3) | 0.270 (2) | 0.063 (6)* | |
H110 | 0.171 (4) | 0.314 (3) | −0.025 (2) | 0.082 (8)* | |
H111 | 0.267 (3) | 0.131 (3) | −0.027 (3) | 0.078 (8)* | |
H10 | 0.397 (3) | 0.577 (3) | 0.253 (2) | 0.054 (6)* | |
H11 | 0.479 (3) | 0.583 (3) | 0.383 (2) | 0.059 (6)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1 | 0.0469 (8) | 0.0356 (8) | 0.0328 (8) | −0.0195 (6) | −0.0102 (7) | −0.0014 (6) |
O2 | 0.0690 (9) | 0.0520 (8) | 0.0344 (7) | −0.0301 (6) | −0.0203 (6) | 0.0048 (6) |
O3 | 0.0725 (9) | 0.0650 (9) | 0.0380 (8) | −0.0219 (7) | 0.0160 (7) | −0.0052 (6) |
O4 | 0.0331 (6) | 0.0417 (6) | 0.0298 (6) | −0.0112 (5) | 0.0009 (5) | −0.0062 (5) |
C1 | 0.0274 (7) | 0.0269 (7) | 0.0283 (8) | −0.0067 (6) | −0.0041 (6) | −0.0032 (6) |
C2 | 0.0325 (8) | 0.0410 (10) | 0.0392 (10) | −0.0121 (7) | 0.0039 (7) | −0.0087 (8) |
C3 | 0.0284 (9) | 0.0539 (12) | 0.0643 (13) | −0.0113 (8) | −0.0026 (8) | −0.0118 (10) |
C4 | 0.0378 (9) | 0.0455 (10) | 0.0491 (11) | −0.0073 (7) | −0.0221 (8) | −0.0013 (8) |
C5 | 0.0419 (9) | 0.0398 (9) | 0.0309 (9) | −0.0144 (7) | −0.0121 (7) | −0.0051 (7) |
C6 | 0.0284 (7) | 0.0282 (7) | 0.0244 (7) | −0.0103 (6) | −0.0010 (6) | −0.0019 (6) |
C7 | 0.0376 (9) | 0.0300 (8) | 0.0464 (10) | −0.0018 (7) | −0.0136 (8) | −0.0005 (8) |
C8 | 0.0334 (8) | 0.0284 (7) | 0.0291 (8) | −0.0060 (6) | −0.0049 (6) | −0.0066 (6) |
C9 | 0.0637 (13) | 0.0500 (12) | 0.0584 (14) | −0.0241 (10) | −0.0141 (11) | −0.0167 (10) |
C10 | 0.0441 (10) | 0.0319 (9) | 0.0406 (10) | −0.0016 (7) | −0.0089 (8) | −0.0016 (7) |
C11 | 0.0651 (13) | 0.0670 (14) | 0.0298 (10) | −0.0192 (11) | −0.0124 (9) | −0.0069 (9) |
C12 | 0.0536 (10) | 0.0378 (9) | 0.0277 (9) | −0.0099 (8) | 0.0020 (8) | −0.0034 (7) |
N1—C8 | 1.326 (2) | C4—C5 | 1.552 (2) |
N1—H10 | 0.91 (2) | C4—H4 | 0.97 (2) |
N1—H11 | 0.89 (2) | C5—C9 | 1.531 (2) |
O2—C8 | 1.2349 (19) | C5—C11 | 1.533 (3) |
O3—C12 | 1.202 (2) | C5—C6 | 1.573 (2) |
O4—C12 | 1.335 (2) | C6—C10 | 1.513 (2) |
O4—C6 | 1.4714 (16) | C7—H71 | 0.97 (2) |
C1—C8 | 1.512 (2) | C7—H72 | 0.979 (16) |
C1—C7 | 1.540 (2) | C9—H91 | 1.00 (2) |
C1—C2 | 1.546 (2) | C9—H92 | 0.97 (3) |
C1—C6 | 1.551 (2) | C9—H93 | 0.99 (2) |
C2—C3 | 1.538 (3) | C10—H101 | 0.97 (3) |
C2—H21 | 1.027 (18) | C10—H102 | 0.99 (2) |
C2—H22 | 1.01 (2) | C10—H103 | 0.98 (2) |
C3—C4 | 1.526 (3) | C11—C12 | 1.492 (3) |
C3—H31 | 1.02 (2) | C11—H110 | 0.96 (3) |
C3—H32 | 0.96 (2) | C11—H111 | 0.91 (3) |
C4—C7 | 1.534 (2) | ||
C8—N1—H10 | 120.3 (13) | O4—C6—C1 | 107.26 (11) |
C8—N1—H11 | 117.4 (14) | C10—C6—C1 | 116.77 (13) |
H10—N1—H11 | 121.0 (19) | O4—C6—C5 | 106.01 (11) |
C12—O4—C6 | 112.40 (12) | C10—C6—C5 | 118.10 (13) |
C8—C1—C7 | 119.50 (13) | C1—C6—C5 | 103.22 (11) |
C8—C1—C2 | 111.80 (12) | C4—C7—C1 | 94.22 (12) |
C7—C1—C2 | 101.23 (13) | C4—C7—H71 | 115.3 (12) |
C8—C1—C6 | 114.09 (12) | C1—C7—H71 | 109.9 (12) |
C7—C1—C6 | 101.17 (12) | C4—C7—H72 | 114.6 (10) |
C2—C1—C6 | 107.58 (12) | C1—C7—H72 | 113.0 (10) |
C3—C2—C1 | 103.89 (13) | H71—C7—H72 | 109.2 (15) |
C3—C2—H21 | 113.5 (10) | O2—C8—N1 | 122.17 (15) |
C1—C2—H21 | 111.5 (9) | O2—C8—C1 | 119.81 (13) |
C3—C2—H22 | 112.5 (11) | N1—C8—C1 | 118.00 (14) |
C1—C2—H22 | 109.8 (10) | C5—C9—H91 | 111.8 (13) |
H21—C2—H22 | 105.7 (14) | C5—C9—H92 | 108.2 (16) |
C4—C3—C2 | 102.89 (13) | H91—C9—H92 | 109.9 (18) |
C4—C3—H31 | 110.1 (12) | C5—C9—H93 | 112.0 (13) |
C2—C3—H31 | 110.3 (13) | H91—C9—H93 | 110.3 (18) |
C4—C3—H32 | 113.3 (13) | H92—C9—H93 | 104 (2) |
C2—C3—H32 | 114.1 (13) | C6—C10—H101 | 108.3 (13) |
H31—C3—H32 | 106.1 (17) | C6—C10—H102 | 111.6 (11) |
C3—C4—C7 | 101.05 (15) | H101—C10—H102 | 112.2 (18) |
C3—C4—C5 | 110.33 (14) | C6—C10—H103 | 108.2 (12) |
C7—C4—C5 | 102.39 (13) | H101—C10—H103 | 108.1 (18) |
C3—C4—H4 | 114.4 (11) | H102—C10—H103 | 108.2 (17) |
C7—C4—H4 | 117.0 (12) | C12—C11—C5 | 107.10 (15) |
C5—C4—H4 | 110.7 (12) | C12—C11—H110 | 109.9 (15) |
C9—C5—C11 | 110.84 (16) | C5—C11—H110 | 111.7 (14) |
C9—C5—C4 | 113.29 (15) | C12—C11—H111 | 107.6 (16) |
C11—C5—C4 | 111.81 (16) | C5—C11—H111 | 115.3 (16) |
C9—C5—C6 | 115.04 (15) | H110—C11—H111 | 105 (2) |
C11—C5—C6 | 103.15 (13) | O3—C12—O4 | 120.98 (17) |
C4—C5—C6 | 102.04 (12) | O3—C12—C11 | 127.97 (17) |
O4—C6—C10 | 104.66 (12) | O4—C12—C11 | 111.04 (14) |
C8—C1—C2—C3 | 160.01 (14) | C4—C5—C6—O4 | −111.46 (12) |
C7—C1—C2—C3 | 31.68 (16) | C9—C5—C6—C10 | 8.6 (2) |
C6—C1—C2—C3 | −73.98 (16) | C11—C5—C6—C10 | −112.21 (17) |
C1—C2—C3—C4 | 4.31 (18) | C4—C5—C6—C10 | 131.69 (15) |
C2—C3—C4—C7 | −39.09 (17) | C9—C5—C6—C1 | −121.93 (16) |
C2—C3—C4—C5 | 68.70 (18) | C11—C5—C6—C1 | 117.25 (14) |
C3—C4—C5—C9 | 52.1 (2) | C4—C5—C6—C1 | 1.15 (14) |
C7—C4—C5—C9 | 159.00 (16) | C3—C4—C7—C1 | 57.55 (14) |
C3—C4—C5—C11 | 178.22 (15) | C5—C4—C7—C1 | −56.36 (15) |
C7—C4—C5—C11 | −74.89 (17) | C8—C1—C7—C4 | −177.35 (13) |
C3—C4—C5—C6 | −72.16 (15) | C2—C1—C7—C4 | −54.16 (15) |
C7—C4—C5—C6 | 34.74 (15) | C6—C1—C7—C4 | 56.51 (14) |
C12—O4—C6—C10 | 119.82 (15) | C7—C1—C8—O2 | 150.48 (16) |
C12—O4—C6—C1 | −115.51 (14) | C2—C1—C8—O2 | 32.62 (19) |
C12—O4—C6—C5 | −5.73 (16) | C6—C1—C8—O2 | −89.74 (17) |
C8—C1—C6—O4 | −54.29 (15) | C7—C1—C8—N1 | −28.0 (2) |
C7—C1—C6—O4 | 75.35 (13) | C2—C1—C8—N1 | −145.89 (14) |
C2—C1—C6—O4 | −178.94 (11) | C6—C1—C8—N1 | 91.76 (16) |
C8—C1—C6—C10 | 62.68 (18) | C9—C5—C11—C12 | −125.98 (18) |
C7—C1—C6—C10 | −167.67 (14) | C4—C5—C11—C12 | 106.57 (18) |
C2—C1—C6—C10 | −61.96 (18) | C6—C5—C11—C12 | −2.3 (2) |
C8—C1—C6—C5 | −165.99 (12) | C6—O4—C12—O3 | −175.02 (14) |
C7—C1—C6—C5 | −36.34 (13) | C6—O4—C12—C11 | 4.3 (2) |
C2—C1—C6—C5 | 69.37 (14) | C5—C11—C12—O3 | 178.28 (17) |
C9—C5—C6—O4 | 125.45 (15) | C5—C11—C12—O4 | −1.0 (2) |
C11—C5—C6—O4 | 4.64 (16) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H10···O3i | 0.91 (2) | 2.17 (2) | 3.065 (2) | 168.7 (18) |
N1—H11···O2ii | 0.89 (2) | 2.02 (3) | 2.912 (2) | 177 (2) |
Symmetry codes: (i) −x+1, −y+1, −z; (ii) −x+1, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C12H17NO3 |
Mr | 223.27 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 296 |
a, b, c (Å) | 7.0659 (3), 7.8206 (3), 10.4595 (3) |
α, β, γ (°) | 79.667 (2), 80.471 (2), 81.579 (2) |
V (Å3) | 556.69 (4) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.10 |
Crystal size (mm) | 0.25 × 0.2 × 0.15 |
Data collection | |
Diffractometer | Bruker SMART APEXII CCD area-detector |
Absorption correction | Multi-scan (SADABS; Bruker, 2008) |
Tmin, Tmax | 0.977, 0.986 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 8729, 2405, 1754 |
Rint | 0.037 |
(sin θ/λ)max (Å−1) | 0.638 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.044, 0.141, 0.92 |
No. of reflections | 2405 |
No. of parameters | 213 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.17, −0.21 |
Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H10···O3i | 0.91 (2) | 2.17 (2) | 3.065 (2) | 168.7 (18) |
N1—H11···O2ii | 0.89 (2) | 2.02 (3) | 2.912 (2) | 177 (2) |
Symmetry codes: (i) −x+1, −y+1, −z; (ii) −x+1, −y+1, −z+1. |
References
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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.
Nitroimines and their derivatives have found a numerous applications in organic synthesis (Squire et al., 2002; Bulman Page et al., 2000; Lalk et al., 1999), as organocatalysis (Parrott, R. W. et al., 2008) and in medicinal chemistry (Ranise et al., 1990; Bondavalli, et al., 1987). Herein, we report synthesis and crystal structure of the title compound (II), the novel 3,7-dimethyl-3-oxohexahydro-4,7-methano-2-benzofuran-4(1H)-carboxamide , C12H17NO3 (Fig. 1)obtained via selective Wagner-Meerwein type rearrangement of potassium cyanide adducts of 1,7-dimethyl-2-(nitroimino)bicyclo[2.2.1]hept-7-ylacetic acid (I) (see Fig. 2).
In the structure of (II) (Fig. 1), angle deviations at Csp3 atoms range from 94.22 to 118.10 (16) °. Thus the C1—C7—C4 angle as in other previously reported compounds has a reduced value of 94.22 (12) ° (Noe et al., 1996; Knollmuller et al., 1998). Most bond distances for compound (I) were in the expected range however, the C5-C6 bond length is 1.573 (2) Å, which is apparently due to steric repulsion between the methyl groups on these atoms, this also leads to an increase in the angles C5C6C10 and C6C5C9 to 118.10 (13) and 115.04 (15) °, respectively. It is interesting to note that the bond O4—C6 is slightly longer (1.4714 (16) Å) and O4—C12 shorter (1.335 (2) Å) compared with the values previously found (average 1.45 and 1.36 Å, respectively). Intermolecular hydrogen bonds are formed through N—H···O—C and N—H···O═C between the amide and two O-atom acceptors of lactone group. (Table 1).