Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807031376/hb2450sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807031376/hb2450Isup2.hkl |
CCDC reference: 658982
A small amount of the title compound which arose as a side product in the gold-catalyzed cyclization of α-hydroxyallenes (Erdsack & Krause, 2007) was suspended in a few drops of iso-hexane. Ethyl acetate was added dropwise until the compound was complete dissolved, and colourless blocks of (I) were obtained by slow evaporation at ambient temperature.
The H atoms were placed in calculated positions, with C—H = 0.96–0.98 and N—H = 0.86 Å and refined as riding, with Uiso= 1.5Ueq; the methyl groups were allowed to rotate but not to tip. The –CF3 fluorine atoms are disordered over two positions of equal occupancy.
The title compound, (I),is a side product in the preparation of novel furanomycin derivatives using the gold-catalyzed cyclization of α-hydroxyallenes (Hoffmann-Röder & Krause, 2001; Erdsack & Krause, 2007) (Fig. 1). The torsion angle O3—C3a—C6a—O1 is -95.6 (2)°. Although the synthesis started from enantiomerically pure L-serine, compound (I) crystallizes in a achiral space group (P1): in the arbitrarily chosen asymmetric molecule, the configurations of the stereogenic centres are C3 R, C3A S, C6 R, and C6A R. This raecemization is in contrast to a related compound (Erdsack, Schürmann et al., 2007).
For related literature, see: Erdsack & Krause (2007); Erdsack et al. (2007); Hoffmann-Röder & Krause (2001).
Data collection: COLLECT (Nonius, 1998); cell refinement: DENZO and SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO and SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL-Plus (Sheldrick, 1991); software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003).
C12H15ClF3NO4 | Z = 2 |
Mr = 329.70 | F(000) = 340 |
Triclinic, P1 | Dx = 1.482 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 7.674 (3) Å | Cell parameters from 8179 reflections |
b = 9.586 (3) Å | θ = 3.1–25.3° |
c = 11.590 (4) Å | µ = 0.31 mm−1 |
α = 66.904 (13)° | T = 291 K |
β = 76.782 (14)° | Block, colourless |
γ = 71.684 (13)° | 0.10 × 0.08 × 0.08 mm |
V = 739.1 (4) Å3 |
Nonius KappaCCD area-detector diffractometer | 959 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.031 |
Graphite monochromator | θmax = 25.3°, θmin = 3.1° |
Detector resolution: 19 vertical, 18 horizontal pixels mm-1 | h = −9→9 |
185 frames via ω–rotation (Δω = 2°) and two times 190 s per frame (four sets at different κ–angles) scans | k = −10→11 |
8179 measured reflections | l = −13→13 |
2680 independent 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)] = 0.031 | H-atom parameters constrained |
wR(F2) = 0.079 | w = [1.0 exp(4.90(sinθ/λ)2)]/[σ2(Fo2)] |
S = 0.91 | (Δ/σ)max < 0.001 |
2680 reflections | Δρmax = 0.14 e Å−3 |
219 parameters | Δρmin = −0.12 e Å−3 |
0 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0297 (18) |
C12H15ClF3NO4 | γ = 71.684 (13)° |
Mr = 329.70 | V = 739.1 (4) Å3 |
Triclinic, P1 | Z = 2 |
a = 7.674 (3) Å | Mo Kα radiation |
b = 9.586 (3) Å | µ = 0.31 mm−1 |
c = 11.590 (4) Å | T = 291 K |
α = 66.904 (13)° | 0.10 × 0.08 × 0.08 mm |
β = 76.782 (14)° |
Nonius KappaCCD area-detector diffractometer | 959 reflections with I > 2σ(I) |
8179 measured reflections | Rint = 0.031 |
2680 independent reflections |
R[F2 > 2σ(F2)] = 0.031 | 0 restraints |
wR(F2) = 0.079 | H-atom parameters constrained |
S = 0.91 | Δρmax = 0.14 e Å−3 |
2680 reflections | Δρmin = −0.12 e Å−3 |
219 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) | |
Cl | 0.33628 (12) | 0.95641 (10) | 0.80355 (9) | 0.0743 (3) | |
O1 | 0.8738 (3) | 0.7457 (2) | 0.79610 (18) | 0.0569 (6) | |
C2 | 0.9876 (5) | 0.7001 (4) | 0.8845 (3) | 0.0513 (8) | |
O2 | 1.1278 (3) | 0.5984 (2) | 0.88767 (19) | 0.0630 (6) | |
C3 | 0.9078 (4) | 0.7944 (3) | 0.9721 (3) | 0.0465 (8) | |
H3 | 0.9723 | 0.8774 | 0.9464 | 0.070* | |
C3A | 0.7091 (4) | 0.8701 (3) | 0.9452 (3) | 0.0500 (8) | |
H3A | 0.6688 | 0.9765 | 0.9480 | 0.075* | |
O3 | 0.5884 (3) | 0.7760 (2) | 1.02971 (18) | 0.0617 (6) | |
C5 | 0.5403 (5) | 0.6972 (4) | 0.9643 (3) | 0.0677 (10) | |
H5A | 0.4179 | 0.6799 | 0.9976 | 0.102* | |
H5B | 0.6284 | 0.5968 | 0.9727 | 0.102* | |
C6 | 0.5449 (4) | 0.8043 (3) | 0.8274 (3) | 0.0577 (9) | |
H6 | 0.5670 | 0.7455 | 0.7705 | 0.087* | |
C6A | 0.7094 (4) | 0.8714 (3) | 0.8124 (3) | 0.0494 (8) | |
C7 | 0.7242 (4) | 1.0219 (3) | 0.7034 (3) | 0.0583 (9) | |
H7A | 0.8377 | 1.0462 | 0.7033 | 0.087* | |
H7B | 0.6220 | 1.1064 | 0.7170 | 0.087* | |
C8 | 0.7227 (5) | 1.0161 (4) | 0.5739 (3) | 0.0705 (10) | |
H8A | 0.6093 | 0.9918 | 0.5736 | 0.106* | |
H8B | 0.8254 | 0.9322 | 0.5596 | 0.106* | |
C9 | 0.7371 (6) | 1.1697 (5) | 0.4656 (3) | 0.0884 (12) | |
H9A | 0.8433 | 1.1997 | 0.4716 | 0.133* | |
H9B | 0.7584 | 1.1522 | 0.3860 | 0.133* | |
C10 | 0.5713 (7) | 1.3005 (5) | 0.4645 (4) | 0.1211 (17) | |
H10A | 0.4630 | 1.2668 | 0.4709 | 0.182* | |
H10B | 0.5805 | 1.3870 | 0.3871 | 0.182* | |
H10C | 0.5627 | 1.3325 | 0.5348 | 0.182* | |
N | 0.9323 (3) | 0.6989 (3) | 1.1019 (2) | 0.0534 (7) | |
H0 | 0.8877 | 0.6180 | 1.1363 | 0.080* | |
C11 | 1.0213 (4) | 0.7313 (4) | 1.1703 (3) | 0.0548 (8) | |
O4 | 1.0949 (3) | 0.8376 (3) | 1.13432 (19) | 0.0769 (8) | |
C12 | 1.0293 (8) | 0.6182 (6) | 1.3066 (4) | 0.0761 (12) | |
F1A | 1.019 (3) | 0.691 (2) | 1.3743 (14) | 0.142 (8) | 0.50 |
F2A | 0.896 (3) | 0.543 (2) | 1.347 (2) | 0.131 (8) | 0.50 |
F3A | 1.189 (3) | 0.5103 (18) | 1.3085 (15) | 0.152 (6) | 0.50 |
F1B | 0.950 (3) | 0.6885 (19) | 1.3945 (14) | 0.125 (6) | 0.50 |
F2B | 0.950 (3) | 0.509 (2) | 1.3365 (19) | 0.120 (7) | 0.50 |
F3B | 1.1950 (19) | 0.557 (2) | 1.3374 (14) | 0.151 (7) | 0.50 |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl | 0.0550 (6) | 0.0754 (7) | 0.0948 (7) | −0.0065 (5) | −0.0206 (5) | −0.0334 (5) |
O1 | 0.0550 (15) | 0.0568 (14) | 0.0650 (15) | −0.0057 (12) | −0.0121 (12) | −0.0312 (11) |
C2 | 0.051 (2) | 0.044 (2) | 0.058 (2) | −0.0196 (19) | −0.0050 (19) | −0.0110 (18) |
O2 | 0.0540 (16) | 0.0506 (14) | 0.0762 (16) | −0.0040 (13) | −0.0103 (13) | −0.0193 (12) |
C3 | 0.050 (2) | 0.0396 (18) | 0.051 (2) | −0.0147 (17) | −0.0094 (16) | −0.0127 (16) |
C3A | 0.056 (2) | 0.0449 (18) | 0.053 (2) | −0.0140 (18) | −0.0075 (17) | −0.0184 (15) |
O3 | 0.0581 (16) | 0.0673 (15) | 0.0614 (14) | −0.0248 (13) | −0.0031 (11) | −0.0194 (12) |
C5 | 0.062 (3) | 0.058 (2) | 0.087 (3) | −0.019 (2) | −0.014 (2) | −0.024 (2) |
C6 | 0.048 (2) | 0.053 (2) | 0.080 (3) | −0.0040 (18) | −0.0157 (18) | −0.0339 (19) |
C6A | 0.046 (2) | 0.0496 (19) | 0.061 (2) | −0.0094 (17) | −0.0120 (16) | −0.0271 (17) |
C7 | 0.067 (2) | 0.053 (2) | 0.058 (2) | −0.0166 (19) | −0.0177 (17) | −0.0156 (17) |
C8 | 0.080 (3) | 0.077 (3) | 0.057 (2) | −0.014 (2) | −0.0190 (19) | −0.025 (2) |
C9 | 0.104 (4) | 0.095 (3) | 0.060 (2) | −0.033 (3) | −0.016 (2) | −0.011 (2) |
C10 | 0.142 (5) | 0.083 (3) | 0.115 (4) | −0.011 (3) | −0.049 (3) | −0.006 (3) |
N | 0.0655 (19) | 0.0454 (16) | 0.0494 (16) | −0.0208 (15) | −0.0139 (14) | −0.0074 (13) |
C11 | 0.057 (2) | 0.051 (2) | 0.053 (2) | −0.0059 (18) | −0.0176 (17) | −0.0144 (17) |
O4 | 0.097 (2) | 0.0751 (17) | 0.0720 (16) | −0.0455 (16) | −0.0281 (13) | −0.0117 (13) |
C12 | 0.098 (5) | 0.073 (3) | 0.060 (3) | −0.028 (3) | −0.024 (3) | −0.013 (3) |
F1A | 0.28 (2) | 0.159 (10) | 0.036 (5) | −0.148 (12) | −0.003 (8) | −0.023 (5) |
F2A | 0.148 (9) | 0.171 (17) | 0.076 (6) | −0.108 (11) | −0.011 (5) | 0.009 (9) |
F3A | 0.196 (13) | 0.097 (6) | 0.126 (9) | 0.036 (6) | −0.103 (8) | −0.010 (5) |
F1B | 0.195 (11) | 0.099 (7) | 0.061 (6) | −0.032 (8) | 0.015 (6) | −0.027 (5) |
F2B | 0.24 (2) | 0.065 (4) | 0.066 (7) | −0.070 (8) | −0.052 (10) | 0.011 (4) |
F3B | 0.084 (7) | 0.213 (16) | 0.097 (7) | −0.010 (8) | −0.047 (5) | 0.006 (8) |
Cl—C6 | 1.784 (3) | C8—H8A | 0.9700 |
O1—C2 | 1.350 (3) | C8—H8B | 0.9700 |
O1—C6A | 1.481 (3) | C9—C10 | 1.477 (5) |
C2—O2 | 1.200 (3) | C9—H9A | 0.9700 |
C2—C3 | 1.521 (4) | C9—H9B | 0.9700 |
C3—N | 1.441 (3) | C10—H10A | 0.9600 |
C3—C3A | 1.514 (4) | C10—H10B | 0.9600 |
C3—H3 | 0.9800 | C10—H10C | 0.9600 |
C3A—O3 | 1.431 (3) | N—C11 | 1.329 (3) |
C3A—C6A | 1.534 (4) | N—H0 | 0.8600 |
C3A—H3A | 0.9800 | C11—O4 | 1.205 (3) |
O3—C5 | 1.425 (3) | C11—C12 | 1.528 (5) |
C5—C6 | 1.515 (4) | C12—F1A | 1.213 (16) |
C5—H5A | 0.9700 | C12—F2B | 1.269 (16) |
C5—H5B | 0.9700 | C12—F3B | 1.290 (15) |
C6—C6A | 1.537 (4) | C12—F3A | 1.328 (18) |
C6—H6 | 0.9800 | C12—F2A | 1.332 (18) |
C6A—C7 | 1.516 (4) | C12—F1B | 1.364 (16) |
C7—C8 | 1.526 (4) | F1A—F1B | 0.53 (4) |
C7—H7A | 0.9700 | F1A—F3B | 1.65 (3) |
C7—H7B | 0.9700 | F3A—F3B | 0.67 (3) |
C8—C9 | 1.532 (4) | ||
C2—O1—C6A | 111.6 (2) | C10—C9—C8 | 113.9 (3) |
O2—C2—O1 | 121.7 (3) | C10—C9—H9A | 108.8 |
O2—C2—C3 | 128.7 (3) | C8—C9—H9A | 108.8 |
O1—C2—C3 | 109.6 (3) | C10—C9—H9B | 108.8 |
N—C3—C3A | 115.4 (2) | C8—C9—H9B | 108.8 |
N—C3—C2 | 111.9 (3) | H9A—C9—H9B | 107.7 |
C3A—C3—C2 | 104.3 (2) | C9—C10—H10A | 109.5 |
N—C3—H3 | 108.3 | C9—C10—H10B | 109.5 |
C3A—C3—H3 | 108.3 | H10A—C10—H10B | 109.5 |
C2—C3—H3 | 108.3 | C9—C10—H10C | 109.5 |
O3—C3A—C3 | 111.3 (2) | H10A—C10—H10C | 109.5 |
O3—C3A—C6A | 107.2 (2) | H10B—C10—H10C | 109.5 |
C3—C3A—C6A | 104.3 (2) | C11—N—C3 | 122.4 (2) |
O3—C3A—H3A | 111.2 | C11—N—H0 | 118.8 |
C3—C3A—H3A | 111.2 | C3—N—H0 | 118.8 |
C6A—C3A—H3A | 111.2 | O4—C11—N | 126.4 (3) |
C5—O3—C3A | 108.9 (2) | O4—C11—C12 | 119.1 (3) |
O3—C5—C6 | 105.6 (2) | N—C11—C12 | 114.5 (3) |
O3—C5—H5A | 110.6 | F1A—C12—F2B | 123.9 (13) |
C6—C5—H5A | 110.6 | F1A—C12—F3B | 82.6 (12) |
O3—C5—H5B | 110.6 | F2B—C12—F3B | 108.5 (13) |
C6—C5—H5B | 110.6 | F1A—C12—F3A | 111.9 (13) |
H5A—C5—H5B | 108.8 | F2B—C12—F3A | 87.0 (13) |
C5—C6—C6A | 101.5 (2) | F3B—C12—F3A | 29.8 (12) |
C5—C6—Cl | 110.3 (2) | F1A—C12—F2A | 110.0 (14) |
C6A—C6—Cl | 110.6 (2) | F2B—C12—F2A | 20.3 (18) |
C5—C6—H6 | 111.3 | F3B—C12—F2A | 124.4 (14) |
C6A—C6—H6 | 111.3 | F3A—C12—F2A | 106.7 (12) |
Cl—C6—H6 | 111.3 | F1A—C12—F1B | 22.8 (16) |
O1—C6A—C7 | 108.3 (2) | F2B—C12—F1B | 104.4 (13) |
O1—C6A—C3A | 104.4 (2) | F3B—C12—F1B | 100.4 (11) |
C7—C6A—C3A | 116.8 (2) | F3A—C12—F1B | 126.9 (11) |
O1—C6A—C6 | 104.2 (2) | F2A—C12—F1B | 88.2 (13) |
C7—C6A—C6 | 118.1 (3) | F1A—C12—C11 | 108.9 (9) |
C3A—C6A—C6 | 103.5 (2) | F2B—C12—C11 | 115.1 (10) |
C6A—C7—C8 | 114.2 (2) | F3B—C12—C11 | 113.4 (7) |
C6A—C7—H7A | 108.7 | F3A—C12—C11 | 106.8 (9) |
C8—C7—H7A | 108.7 | F2A—C12—C11 | 112.6 (11) |
C6A—C7—H7B | 108.7 | F1B—C12—C11 | 113.8 (8) |
C8—C7—H7B | 108.7 | F1B—F1A—C12 | 95 (3) |
H7A—C7—H7B | 107.6 | F1B—F1A—F3B | 131 (4) |
C7—C8—C9 | 113.2 (3) | C12—F1A—F3B | 50.7 (9) |
C7—C8—H8A | 108.9 | F3B—F3A—C12 | 72 (3) |
C9—C8—H8A | 108.9 | F1A—F1B—C12 | 62 (3) |
C7—C8—H8B | 108.9 | F3A—F3B—C12 | 78 (3) |
C9—C8—H8B | 108.9 | F3A—F3B—F1A | 124 (3) |
H8A—C8—H8B | 107.8 | C12—F3B—F1A | 46.7 (8) |
C6A—O1—C2—O2 | 179.4 (2) | O4—C11—C12—F3B | −53.6 (12) |
C6A—O1—C2—C3 | −0.1 (3) | N—C11—C12—F3B | 125.6 (10) |
O2—C2—C3—N | −39.3 (4) | O4—C11—C12—F3A | −84.7 (9) |
O1—C2—C3—N | 140.1 (2) | N—C11—C12—F3A | 94.6 (9) |
O2—C2—C3—C3A | −164.7 (3) | O4—C11—C12—F2A | 158.6 (11) |
O1—C2—C3—C3A | 14.7 (3) | N—C11—C12—F2A | −22.1 (12) |
N—C3—C3A—O3 | −30.3 (3) | O4—C11—C12—F1B | 60.2 (11) |
C2—C3—C3A—O3 | 92.8 (2) | N—C11—C12—F1B | −120.5 (10) |
N—C3—C3A—C6A | −145.6 (2) | F2B—C12—F1A—F1B | −34 (5) |
C2—C3—C3A—C6A | −22.5 (3) | F3B—C12—F1A—F1B | −141 (4) |
C3—C3A—O3—C5 | −103.4 (3) | F3A—C12—F1A—F1B | −136 (4) |
C6A—C3A—O3—C5 | 10.1 (3) | F2A—C12—F1A—F1B | −17 (4) |
C3A—O3—C5—C6 | −30.0 (3) | C11—C12—F1A—F1B | 107 (4) |
O3—C5—C6—C6A | 36.8 (3) | F2B—C12—F1A—F3B | 107.3 (16) |
O3—C5—C6—Cl | −80.5 (2) | F3A—C12—F1A—F3B | 5.6 (15) |
C2—O1—C6A—C7 | 110.7 (2) | F2A—C12—F1A—F3B | 124.0 (14) |
C2—O1—C6A—C3A | −14.4 (3) | F1B—C12—F1A—F3B | 141 (4) |
C2—O1—C6A—C6 | −122.7 (2) | C11—C12—F1A—F3B | −112.2 (9) |
O3—C3A—C6A—O1 | −95.6 (2) | F1A—C12—F3A—F3B | −11 (3) |
C3—C3A—C6A—O1 | 22.6 (2) | F2B—C12—F3A—F3B | −137 (3) |
O3—C3A—C6A—C7 | 144.8 (3) | F2A—C12—F3A—F3B | −132 (3) |
C3—C3A—C6A—C7 | −97.0 (3) | F1B—C12—F3A—F3B | −31 (3) |
O3—C3A—C6A—C6 | 13.2 (3) | C11—C12—F3A—F3B | 108 (2) |
C3—C3A—C6A—C6 | 131.4 (2) | F3B—F1A—F1B—C12 | −40 (3) |
C5—C6—C6A—O1 | 79.4 (3) | F2B—C12—F1B—F1A | 151 (4) |
Cl—C6—C6A—O1 | −163.56 (18) | F3B—C12—F1B—F1A | 39 (4) |
C5—C6—C6A—C7 | −160.4 (3) | F3A—C12—F1B—F1A | 54 (4) |
Cl—C6—C6A—C7 | −43.4 (3) | F2A—C12—F1B—F1A | 164 (4) |
C5—C6—C6A—C3A | −29.6 (3) | C11—C12—F1B—F1A | −82 (4) |
Cl—C6—C6A—C3A | 87.5 (3) | C12—F3A—F3B—F1A | 9 (2) |
O1—C6A—C7—C8 | 62.9 (3) | F1A—C12—F3B—F3A | 170 (3) |
C3A—C6A—C7—C8 | −179.7 (3) | F2B—C12—F3B—F3A | 46 (3) |
C6—C6A—C7—C8 | −55.2 (4) | F2A—C12—F3B—F3A | 60 (3) |
C6A—C7—C8—C9 | 179.8 (3) | F1B—C12—F3B—F3A | 155 (3) |
C7—C8—C9—C10 | −69.0 (4) | C11—C12—F3B—F3A | −83 (3) |
C3A—C3—N—C11 | −118.5 (3) | F2B—C12—F3B—F1A | −123.4 (13) |
C2—C3—N—C11 | 122.5 (3) | F3A—C12—F3B—F1A | −170 (3) |
C3—N—C11—O4 | −2.0 (5) | F2A—C12—F3B—F1A | −109.2 (16) |
C3—N—C11—C12 | 178.8 (4) | F1B—C12—F3B—F1A | −14.3 (14) |
O4—C11—C12—F1A | 36.3 (13) | C11—C12—F3B—F1A | 107.4 (11) |
N—C11—C12—F1A | −144.4 (12) | F1B—F1A—F3B—F3A | 43 (6) |
O4—C11—C12—F2B | −179.4 (12) | C12—F1A—F3B—F3A | −12 (3) |
N—C11—C12—F2B | −0.1 (13) | F1B—F1A—F3B—C12 | 56 (5) |
Experimental details
Crystal data | |
Chemical formula | C12H15ClF3NO4 |
Mr | 329.70 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 291 |
a, b, c (Å) | 7.674 (3), 9.586 (3), 11.590 (4) |
α, β, γ (°) | 66.904 (13), 76.782 (14), 71.684 (13) |
V (Å3) | 739.1 (4) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.31 |
Crystal size (mm) | 0.10 × 0.08 × 0.08 |
Data collection | |
Diffractometer | Nonius KappaCCD area-detector |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 8179, 2680, 959 |
Rint | 0.031 |
(sin θ/λ)max (Å−1) | 0.602 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.031, 0.079, 0.91 |
No. of reflections | 2680 |
No. of parameters | 219 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.14, −0.12 |
Computer programs: COLLECT (Nonius, 1998), DENZO and SCALEPACK (Otwinowski & Minor, 1997), DENZO and SCALEPACK, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL-Plus (Sheldrick, 1991), SHELXTL and PLATON (Spek, 2003).
The title compound, (I),is a side product in the preparation of novel furanomycin derivatives using the gold-catalyzed cyclization of α-hydroxyallenes (Hoffmann-Röder & Krause, 2001; Erdsack & Krause, 2007) (Fig. 1). The torsion angle O3—C3a—C6a—O1 is -95.6 (2)°. Although the synthesis started from enantiomerically pure L-serine, compound (I) crystallizes in a achiral space group (P1): in the arbitrarily chosen asymmetric molecule, the configurations of the stereogenic centres are C3 R, C3A S, C6 R, and C6A R. This raecemization is in contrast to a related compound (Erdsack, Schürmann et al., 2007).