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The title compound, C
8H
13NO, with two chiral centres in the
cis-junction between the β-lactam and cycloheptane rings, crystallizes with an orthorhombic unit cell. The strain of the β-lactam moiety forces the cycloheptane ring to assume a chair conformation characterized by
Cs symmetry, which is less stable by 1.4 kcal mol
−1 than the twist-chair form, built up around a twofold axis. The homochiral helices, maintained by N—H
O=C hydrogen bonds, are organized in antiparallel mode around the respective screw axes of the non-centrosymmetric space group
P2
12
12
1, which means that the enantiomers resolve in crystal conglomerates.
Supporting information
CCDC reference: 234856
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.005 Å
- R factor = 0.066
- wR factor = 0.227
- Data-to-parameter ratio = 10.3
checkCIF/PLATON results
No syntax errors found
Alert level C
PLAT340_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ... 5
Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
correct. If it is not, please give the correct count in the
_publ_section_exptl_refinement section of the submitted CIF.
From the CIF: _diffrn_reflns_theta_max 74.85
From the CIF: _reflns_number_total 941
Count of symmetry unique reflns 954
Completeness (_total/calc) 98.64%
TEST3: Check Friedels for noncentro structure
Estimate of Friedel pairs measured 0
Fraction of Friedel pairs measured 0.000
Are heavy atom types Z>Si present no
0 ALERT level A = In general: serious problem
0 ALERT level B = Potentially serious problem
1 ALERT level C = Check and explain
1 ALERT level G = General alerts; check
0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
0 ALERT type 2 Indicator that the structure model may be wrong or deficient
1 ALERT type 3 Indicator that the structure quality may be low
1 ALERT type 4 Improvement, methodology, query or suggestion
Data collection: CAD-4 EXPRESS (Enraf-Nonius, 1992); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms 1996); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997) and RPluto in CSD (Allen, F. H. (2002); software used to prepare material for publication: SHELXL97.
cis-8-azabicyclo[5.2.0]nonan-9-one
top
Crystal data top
C8H13NO | Dx = 1.189 Mg m−3 |
Mr = 139.19 | Melting point = 328–329 K |
Orthorhombic, P212121 | Cu Kα radiation, λ = 1.54180 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 25 reflections |
a = 6.683 (1) Å | θ = 24.3–25.5° |
b = 9.166 (1) Å | µ = 0.62 mm−1 |
c = 12.696 (2) Å | T = 293 K |
V = 777.71 (19) Å3 | Prism, colourless |
Z = 4 | 0.35 × 0.20 × 0.15 mm |
F(000) = 304 | |
Data collection top
Enraf-Nonius CAD4 diffractometer | 842 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.017 |
Graphite monochromator | θmax = 74.9°, θmin = 6.0° |
ω–θ scans | h = −8→8 |
Absorption correction: ψ scan (North et al., 1968) | k = −11→11 |
Tmin = 0.892, Tmax = 0.910 | l = −15→15 |
1863 measured reflections | 3 standard reflections every 60 min |
941 independent reflections | intensity decay: 16% |
Refinement top
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)] = 0.066 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.227 | H-atom parameters constrained |
S = 1.98 | w = 1/[σ2(Fo2) + (0.1P)2] where P = (Fo2 + 2Fc2)/3 |
941 reflections | (Δ/σ)max < 0.001 |
91 parameters | Δρmax = 0.23 e Å−3 |
86 restraints | Δρmin = −0.28 e Å−3 |
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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
C1 | 0.4015 (4) | 0.4291 (4) | 0.2136 (2) | 0.0546 (7) | |
H1 | 0.3830 | 0.5342 | 0.2033 | 0.071* | |
C2 | 0.4753 (4) | 0.3970 (4) | 0.3239 (2) | 0.0539 (7) | |
H2A | 0.5070 | 0.2940 | 0.3290 | 0.070* | |
H2B | 0.5976 | 0.4513 | 0.3361 | 0.070* | |
C3 | 0.3248 (5) | 0.4357 (4) | 0.4092 (2) | 0.0624 (9) | |
H3A | 0.3963 | 0.4493 | 0.4750 | 0.081* | |
H3B | 0.2630 | 0.5282 | 0.3912 | 0.081* | |
C4 | 0.1599 (6) | 0.3236 (5) | 0.4268 (3) | 0.0734 (10) | |
H4A | 0.0787 | 0.3558 | 0.4857 | 0.095* | |
H4B | 0.2221 | 0.2322 | 0.4471 | 0.095* | |
C5 | 0.0210 (5) | 0.2938 (5) | 0.3335 (3) | 0.0715 (10) | |
H5A | −0.0425 | 0.3847 | 0.3130 | 0.093* | |
H5B | −0.0837 | 0.2275 | 0.3561 | 0.093* | |
C6 | 0.1239 (5) | 0.2294 (4) | 0.2382 (3) | 0.0657 (9) | |
H6A | 0.2252 | 0.1609 | 0.2617 | 0.085* | |
H6B | 0.0265 | 0.1755 | 0.1970 | 0.085* | |
C7 | 0.2206 (5) | 0.3426 (4) | 0.1692 (2) | 0.0609 (8) | |
H7 | 0.1206 | 0.4083 | 0.1386 | 0.079* | |
N8 | 0.3600 (5) | 0.2879 (4) | 0.0878 (2) | 0.0723 (9) | |
H8 | 0.3438 | 0.2285 | 0.0361 | 0.094* | |
C9 | 0.5201 (5) | 0.3623 (4) | 0.1218 (2) | 0.0630 (8) | |
O1 | 0.6909 (4) | 0.3724 (4) | 0.0909 (2) | 0.0895 (10) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C1 | 0.0524 (15) | 0.0613 (15) | 0.0499 (14) | 0.0004 (13) | 0.0036 (11) | −0.0037 (11) |
C2 | 0.0428 (13) | 0.0676 (16) | 0.0511 (14) | 0.0004 (12) | −0.0005 (11) | −0.0063 (12) |
C3 | 0.0613 (19) | 0.0773 (19) | 0.0488 (13) | 0.0043 (15) | 0.0045 (14) | −0.0116 (14) |
C4 | 0.0635 (19) | 0.097 (2) | 0.0593 (17) | −0.0014 (19) | 0.0131 (14) | 0.0051 (16) |
C5 | 0.0472 (15) | 0.087 (2) | 0.080 (2) | −0.0049 (16) | 0.0019 (15) | 0.0166 (18) |
C6 | 0.0565 (15) | 0.0700 (17) | 0.0705 (18) | −0.0115 (15) | −0.0135 (14) | 0.0045 (15) |
C7 | 0.0574 (16) | 0.0743 (18) | 0.0511 (14) | 0.0031 (15) | −0.0125 (12) | 0.0026 (14) |
N8 | 0.0811 (18) | 0.0895 (19) | 0.0464 (12) | 0.0014 (16) | −0.0085 (13) | −0.0136 (13) |
C9 | 0.0664 (17) | 0.0780 (18) | 0.0447 (13) | 0.0035 (16) | 0.0049 (12) | −0.0052 (13) |
O1 | 0.0736 (17) | 0.125 (2) | 0.0703 (15) | −0.0044 (17) | 0.0238 (14) | −0.0227 (16) |
Geometric parameters (Å, º) top
C1—C2 | 1.513 (4) | C4—H4B | 0.9700 |
C1—C7 | 1.552 (4) | C5—C6 | 1.511 (5) |
C1—C9 | 1.537 (4) | C5—H5A | 0.9700 |
C1—H1 | 0.9800 | C5—H5B | 0.9700 |
C2—C3 | 1.521 (4) | C6—C7 | 1.505 (5) |
C2—H2A | 0.9700 | C6—H6A | 0.9700 |
C2—H2B | 0.9700 | C6—H6B | 0.9700 |
C3—C4 | 1.524 (5) | C7—N8 | 1.478 (4) |
C3—H3A | 0.9700 | C7—H7 | 0.9800 |
C3—H3B | 0.9700 | N8—C9 | 1.340 (5) |
C4—C5 | 1.530 (5) | N8—H8 | 0.8600 |
C4—H4A | 0.9700 | C9—O1 | 1.210 (4) |
| | | |
C2—C1—C7 | 119.4 (3) | C4—C5—C6 | 114.4 (3) |
C2—C1—C9 | 117.1 (2) | C4—C5—H5A | 108.7 |
C7—C1—C9 | 85.6 (2) | C6—C5—H5A | 108.7 |
C2—C1—H1 | 110.8 | C4—C5—H5B | 108.7 |
C7—C1—H1 | 110.8 | C6—C5—H5B | 108.7 |
C9—C1—H1 | 110.8 | H5A—C5—H5B | 107.6 |
C3—C2—C1 | 113.5 (2) | C7—C6—C5 | 113.1 (3) |
C3—C2—H2A | 108.9 | C7—C6—H6A | 109.0 |
C1—C2—H2A | 108.9 | C5—C6—H6A | 109.0 |
C3—C2—H2B | 108.9 | C7—C6—H6B | 109.0 |
C1—C2—H2B | 108.9 | C5—C6—H6B | 109.0 |
H2A—C2—H2B | 107.7 | H6A—C6—H6B | 107.8 |
C4—C3—C2 | 115.2 (3) | N8—C7—C6 | 116.4 (3) |
C4—C3—H3A | 108.5 | N8—C7—C1 | 86.3 (2) |
C2—C3—H3A | 108.5 | C6—C7—C1 | 118.4 (2) |
C4—C3—H3B | 108.5 | N8—C7—H7 | 111.2 |
C2—C3—H3B | 108.5 | C6—C7—H7 | 111.2 |
H3A—C3—H3B | 107.5 | C1—C7—H7 | 111.2 |
C3—C4—C5 | 116.4 (3) | C9—N8—C7 | 96.1 (2) |
C3—C4—H4A | 108.2 | C9—N8—H8 | 132.0 |
C5—C4—H4A | 108.2 | C7—N8—H8 | 132.0 |
C3—C4—H4B | 108.2 | O1—C9—N8 | 133.4 (3) |
C5—C4—H4B | 108.2 | O1—C9—C1 | 134.6 (3) |
H4A—C4—H4B | 107.3 | N8—C9—C1 | 92.0 (2) |
| | | |
C7—C1—C2—C3 | −65.4 (4) | C2—C1—C7—C6 | 0.3 (4) |
C9—C1—C2—C3 | −166.3 (3) | C9—C1—C7—C6 | 119.0 (3) |
C1—C2—C3—C4 | 80.4 (4) | C6—C7—N8—C9 | −121.0 (3) |
C2—C3—C4—C5 | −61.9 (4) | C1—C7—N8—C9 | −1.0 (3) |
C3—C4—C5—C6 | 63.3 (4) | C7—N8—C9—O1 | −178.6 (5) |
C4—C5—C6—C7 | −83.5 (4) | C7—N8—C9—C1 | 1.0 (3) |
C5—C6—C7—N8 | 167.3 (3) | C2—C1—C9—O1 | −60.5 (6) |
C5—C6—C7—C1 | 66.5 (4) | C7—C1—C9—O1 | 178.7 (5) |
C2—C1—C7—N8 | −117.9 (3) | C2—C1—C9—N8 | 119.9 (3) |
C9—C1—C7—N8 | 0.9 (2) | C7—C1—C9—N8 | −1.0 (3) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N8—H8···O1i | 0.86 | 2.12 | 2.929 (4) | 157 |
Symmetry code: (i) x−1/2, −y+1/2, −z. |
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