organic compounds
(2R)-8-Benzyl-2-[(S)-hydroxy(phenyl)methyl]-8-azabicyclo[3.2.1]octan-3-one
aSynchrotron Radiation Research Section, MCL, National Cancer Institute, Argonne National Laboratory, Biosciences Division, Bldg. 202, Argonne, IL 60439, USA, and bInstitute of Chemistry, University of Bialystok, Hurtowa 1, 15-399 Bialystok, Poland
*Correspondence e-mail: kbrzezinski@anl.gov
The crystal of the title compound, C21H23NO2, was chosen from a conglomerate formed by a An intramolecular hydrogen bond is formed between hydroxy group and heterocyclic N atom of the azabicyclo[3.2.1]octan-3-one system. The is stabilized by C—H⋯O interactions between aliphatic C—H groups and the carbonyl O atom. For the title chiral crystal, the highly redundant and accurate diffraction data set collected with low energy copper radiation gave a of 0.12 (18) for effects originating from O atoms.
Related literature
For recent background literature on the chemistry of related tropane-derived aldols and their applications, including stereoselective syntheses of bioactive et al. (2011); Sienkiewicz et al. (2009) and references cited therein. For stereoselective syntheses of related nortropinone aldols, see: Lazny et al. (2001); Lazny & Nodzewska (2003). For a representative review of the biological activity of tropane derivatives, see: Singh (2000).
see: LaznyExperimental
Crystal data
|
Data collection: CrysAlis PRO (Agilent, 2011); cell CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXD (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and pyMOL (DeLano, 2002); software used to prepare material for publication: SHELXL97.
Supporting information
10.1107/S1600536811053190/gk2429sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536811053190/gk2429Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536811053190/gk2429Isup3.cml
A solution of n-butyllithium in hexane (2.4 M, 0.50 ml, 1.2 mmol) was added dropwise to a cooled (273 K) solution of diisopropylamine (0.168 ml, 1.2 mmol) in tetrahydrofuran (10 ml). The mixture was stirred for 30 min, then cooled to 195 K and a solution of N-benzylnortropinone (0.215 g, 1 mmol) in tetrahydrofuran (7 ml) was added dropwise. After stirring for 2 h, benzaldehyde (0.117 ml, 1.15 mmol) was added dropwise and the mixture was stirred for another 10 min. The reaction was quenched with saturated aq. NH4Cl (4 ml), allowed to warm to room temperature, and extracted with dichloromethane (3 × 10 ml). The combined extracts were dried over MgSO4 and concentrated to give the crude product. Crystallization from mixed solvent system hexane/dichloromethane gave the the major product (0.243 g, 75%) as white crystals [m.p. 372–377 K; Rf = 0.77 (10% methanol/dichloromethane); HR (MS-ESI): MNa+, found 344,1640, C21H23NNaO2 requires 344,1626; 1H NMR (CDCl3): 7.43–7.21 (m, 10H), 5.11 (d, J = 3 Hz, 1H), 3.73–3.65 (m, 3H), 3.58–3.57 (m, 1H), 2.82 (ddd, J1 = 1.5 Hz, J2 = 4.5 Hz, J3 = 6 Hz, 1H), 2.45–2.44 (m, 1H), 2.36–2.32 (m, 3H), 1.70–1.66 (m, 2H)].
All hydrogen atoms were constrained to idealized positions with C—H distances fixed at 0.95–1.00 Å and O—H distances fixed at 0.84 Å and Uiso(H) = 1.5Ueq(C) for hydroxyl hydrogen atom and 1.2Ueq(C) for others.
Data collection: CrysAlis PRO (Agilent, 2011); cell
CrysAlis PRO (Agilent, 2011); data reduction: CrysAlis PRO (Agilent, 2011); program(s) used to solve structure: SHELXD (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and pyMOL (DeLano, 2002); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).C21H23NO2 | F(000) = 688 |
Mr = 321.40 | Dx = 1.220 Mg m−3 |
Orthorhombic, P212121 | Cu Kα radiation, λ = 1.54180 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 23874 reflections |
a = 5.9354 (1) Å | θ = 3.3–73.6° |
b = 13.3091 (2) Å | µ = 0.61 mm−1 |
c = 22.1511 (3) Å | T = 100 K |
V = 1749.82 (5) Å3 | Needle, colourless |
Z = 4 | 0.65 × 0.25 × 0.19 mm |
Oxford Diffraction SuperNova Dual diffractometer | 3323 independent reflections |
Radiation source: SuperNova (Cu) X-ray Source | 3276 reflections with I > 2σ(I) |
Mirror monochromator | Rint = 0.026 |
Detector resolution: 10.4052 pixels mm-1 | θmax = 73.6°, θmin = 3.9° |
ω scans | h = −7→6 |
Absorption correction: analytical (CrysAlis PRO; Agilent, 2011) | k = 0→16 |
Tmin = 0.75, Tmax = 0.89 | l = 0→27 |
32829 measured 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)] = 0.027 | H-atom parameters constrained |
wR(F2) = 0.070 | w = 1/[σ2(Fo2) + (0.0283P)2 + 0.4297P] where P = (Fo2 + 2Fc2)/3 |
S = 1.18 | (Δ/σ)max < 0.001 |
3323 reflections | Δρmax = 0.16 e Å−3 |
218 parameters | Δρmin = −0.16 e Å−3 |
0 restraints | Absolute structure: Flack (1983), 1257 Friedel pairs |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.12 (18) |
C21H23NO2 | V = 1749.82 (5) Å3 |
Mr = 321.40 | Z = 4 |
Orthorhombic, P212121 | Cu Kα radiation |
a = 5.9354 (1) Å | µ = 0.61 mm−1 |
b = 13.3091 (2) Å | T = 100 K |
c = 22.1511 (3) Å | 0.65 × 0.25 × 0.19 mm |
Oxford Diffraction SuperNova Dual diffractometer | 3323 independent reflections |
Absorption correction: analytical (CrysAlis PRO; Agilent, 2011) | 3276 reflections with I > 2σ(I) |
Tmin = 0.75, Tmax = 0.89 | Rint = 0.026 |
32829 measured reflections |
R[F2 > 2σ(F2)] = 0.027 | H-atom parameters constrained |
wR(F2) = 0.070 | Δρmax = 0.16 e Å−3 |
S = 1.18 | Δρmin = −0.16 e Å−3 |
3323 reflections | Absolute structure: Flack (1983), 1257 Friedel pairs |
218 parameters | Absolute structure parameter: 0.12 (18) |
0 restraints |
Geometry. All e.s.d.'s 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. |
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 > 2σ(F2) is used only for calculating R-factors 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. |
x | y | z | Uiso*/Ueq | ||
C1 | 0.8760 (2) | 0.63105 (8) | 0.16890 (5) | 0.0158 (2) | |
H1 | 0.9172 | 0.6656 | 0.1304 | 0.019* | |
C2 | 0.8530 (2) | 0.51680 (8) | 0.15913 (5) | 0.0153 (2) | |
H2 | 1.0031 | 0.4903 | 0.1462 | 0.018* | |
C3 | 0.7921 (2) | 0.46720 (9) | 0.21973 (5) | 0.0169 (3) | |
O3 | 0.88275 (17) | 0.38983 (7) | 0.23623 (4) | 0.0256 (2) | |
C4 | 0.6185 (2) | 0.52123 (8) | 0.25898 (5) | 0.0177 (3) | |
H4A | 0.6293 | 0.4967 | 0.3011 | 0.021* | |
H4B | 0.4649 | 0.5066 | 0.2439 | 0.021* | |
C5 | 0.6612 (2) | 0.63510 (8) | 0.25734 (5) | 0.0164 (2) | |
H5 | 0.5476 | 0.6719 | 0.2823 | 0.020* | |
C6 | 0.9079 (2) | 0.65823 (10) | 0.27939 (6) | 0.0202 (3) | |
H6A | 0.9603 | 0.6067 | 0.3084 | 0.024* | |
H6B | 0.9166 | 0.7252 | 0.2987 | 0.024* | |
C7 | 1.0516 (2) | 0.65523 (9) | 0.21957 (6) | 0.0204 (3) | |
H7A | 1.1253 | 0.7208 | 0.2121 | 0.025* | |
H7B | 1.1686 | 0.6024 | 0.2218 | 0.025* | |
N8 | 0.65350 (19) | 0.66906 (7) | 0.19242 (4) | 0.0150 (2) | |
O9 | 0.45290 (16) | 0.52672 (6) | 0.12196 (4) | 0.0204 (2) | |
H9 | 0.4614 | 0.5808 | 0.1414 | 0.031* | |
C9 | 0.6768 (2) | 0.49154 (9) | 0.10786 (5) | 0.0165 (3) | |
H9C | 0.7269 | 0.5263 | 0.0701 | 0.020* | |
C10 | 0.6686 (2) | 0.38004 (9) | 0.09495 (5) | 0.0166 (3) | |
C11 | 0.8557 (3) | 0.33441 (10) | 0.06662 (5) | 0.0210 (3) | |
H11 | 0.9814 | 0.3742 | 0.0551 | 0.025* | |
C12 | 0.8568 (3) | 0.23166 (10) | 0.05557 (6) | 0.0238 (3) | |
H12 | 0.9833 | 0.2009 | 0.0369 | 0.029* | |
C13 | 0.6694 (3) | 0.17393 (9) | 0.07224 (6) | 0.0241 (3) | |
H13 | 0.6699 | 0.1035 | 0.0652 | 0.029* | |
C14 | 0.4813 (3) | 0.21910 (10) | 0.09918 (6) | 0.0226 (3) | |
H14 | 0.3537 | 0.1794 | 0.1093 | 0.027* | |
C15 | 0.4803 (2) | 0.32179 (9) | 0.11116 (5) | 0.0196 (3) | |
H15 | 0.3539 | 0.3522 | 0.1301 | 0.023* | |
C16 | 0.6383 (2) | 0.78046 (8) | 0.19028 (5) | 0.0171 (3) | |
H16A | 0.7639 | 0.8098 | 0.2138 | 0.020* | |
H16B | 0.4952 | 0.8022 | 0.2091 | 0.020* | |
C17 | 0.6486 (2) | 0.81981 (8) | 0.12530 (6) | 0.0176 (3) | |
C18 | 0.4719 (3) | 0.80051 (9) | 0.08410 (6) | 0.0212 (3) | |
H18 | 0.3449 | 0.7626 | 0.0969 | 0.025* | |
C19 | 0.4813 (3) | 0.83679 (10) | 0.02427 (6) | 0.0252 (3) | |
H19 | 0.3614 | 0.8234 | −0.0030 | 0.030* | |
C20 | 0.6690 (3) | 0.89285 (10) | 0.00518 (6) | 0.0262 (3) | |
H20 | 0.6763 | 0.9177 | −0.0350 | 0.031* | |
C21 | 0.8457 (3) | 0.91194 (9) | 0.04567 (6) | 0.0265 (3) | |
H21 | 0.9729 | 0.9494 | 0.0326 | 0.032* | |
C22 | 0.8362 (3) | 0.87590 (9) | 0.10572 (6) | 0.0227 (3) | |
H22 | 0.9564 | 0.8895 | 0.1328 | 0.027* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0150 (6) | 0.0132 (5) | 0.0194 (6) | 0.0009 (5) | 0.0025 (5) | −0.0001 (4) |
C2 | 0.0143 (6) | 0.0129 (5) | 0.0186 (5) | 0.0017 (5) | −0.0010 (5) | −0.0008 (4) |
C3 | 0.0174 (7) | 0.0140 (5) | 0.0192 (6) | −0.0017 (5) | −0.0041 (5) | −0.0006 (5) |
O3 | 0.0324 (6) | 0.0175 (4) | 0.0269 (5) | 0.0076 (4) | −0.0038 (4) | 0.0032 (4) |
C4 | 0.0197 (7) | 0.0154 (5) | 0.0178 (5) | 0.0003 (5) | 0.0000 (5) | 0.0026 (4) |
C5 | 0.0180 (7) | 0.0157 (5) | 0.0156 (5) | 0.0014 (5) | 0.0006 (5) | −0.0002 (4) |
C6 | 0.0210 (8) | 0.0187 (6) | 0.0207 (6) | 0.0000 (5) | −0.0046 (5) | −0.0004 (5) |
C7 | 0.0147 (7) | 0.0183 (6) | 0.0283 (7) | 0.0003 (5) | −0.0008 (5) | −0.0043 (5) |
N8 | 0.0169 (6) | 0.0120 (4) | 0.0160 (5) | 0.0020 (4) | 0.0010 (4) | 0.0004 (4) |
O9 | 0.0178 (5) | 0.0165 (4) | 0.0269 (5) | 0.0037 (3) | −0.0038 (4) | −0.0048 (4) |
C9 | 0.0179 (7) | 0.0157 (5) | 0.0159 (5) | 0.0005 (5) | 0.0003 (5) | 0.0004 (4) |
C10 | 0.0207 (7) | 0.0166 (5) | 0.0126 (5) | 0.0006 (5) | −0.0028 (5) | −0.0009 (4) |
C11 | 0.0220 (7) | 0.0223 (6) | 0.0187 (6) | −0.0001 (5) | 0.0002 (5) | −0.0029 (5) |
C12 | 0.0260 (8) | 0.0246 (6) | 0.0209 (6) | 0.0072 (6) | −0.0024 (6) | −0.0065 (5) |
C13 | 0.0371 (9) | 0.0155 (6) | 0.0196 (6) | 0.0019 (6) | −0.0052 (6) | −0.0030 (5) |
C14 | 0.0309 (8) | 0.0194 (6) | 0.0175 (6) | −0.0055 (6) | −0.0018 (6) | 0.0006 (5) |
C15 | 0.0228 (7) | 0.0197 (6) | 0.0162 (5) | −0.0005 (5) | 0.0008 (5) | −0.0012 (5) |
C16 | 0.0188 (7) | 0.0118 (5) | 0.0206 (6) | 0.0014 (5) | −0.0005 (5) | −0.0013 (4) |
C17 | 0.0194 (7) | 0.0110 (5) | 0.0224 (6) | 0.0034 (5) | 0.0025 (6) | 0.0002 (4) |
C18 | 0.0228 (8) | 0.0171 (6) | 0.0238 (6) | 0.0003 (5) | 0.0003 (5) | 0.0034 (5) |
C19 | 0.0302 (8) | 0.0218 (6) | 0.0235 (6) | 0.0036 (6) | −0.0033 (6) | 0.0021 (5) |
C20 | 0.0369 (9) | 0.0192 (6) | 0.0226 (6) | 0.0066 (6) | 0.0074 (6) | 0.0049 (5) |
C21 | 0.0261 (8) | 0.0187 (6) | 0.0347 (7) | 0.0010 (6) | 0.0113 (6) | 0.0046 (5) |
C22 | 0.0226 (8) | 0.0153 (5) | 0.0303 (7) | 0.0009 (5) | 0.0020 (6) | 0.0007 (5) |
C1—N8 | 1.5071 (16) | C10—C15 | 1.4068 (19) |
C1—C2 | 1.5419 (15) | C10—C11 | 1.4127 (19) |
C1—C7 | 1.5648 (18) | C11—C12 | 1.3893 (18) |
C1—H1 | 1.0000 | C11—H11 | 0.9500 |
C2—C3 | 1.5390 (16) | C12—C13 | 1.401 (2) |
C2—C9 | 1.5801 (16) | C12—H12 | 0.9500 |
C2—H2 | 1.0000 | C13—C14 | 1.401 (2) |
C3—O3 | 1.2180 (15) | C13—H13 | 0.9500 |
C3—C4 | 1.5279 (18) | C14—C15 | 1.3923 (17) |
C4—C5 | 1.5368 (15) | C14—H14 | 0.9500 |
C4—H4A | 0.9900 | C15—H15 | 0.9500 |
C4—H4B | 0.9900 | C16—C17 | 1.5329 (16) |
C5—N8 | 1.5082 (14) | C16—H16A | 0.9900 |
C5—C6 | 1.5742 (18) | C16—H16B | 0.9900 |
C5—H5 | 1.0000 | C17—C22 | 1.4091 (19) |
C6—C7 | 1.5762 (18) | C17—C18 | 1.4140 (19) |
C6—H6A | 0.9900 | C18—C19 | 1.4116 (18) |
C6—H6B | 0.9900 | C18—H18 | 0.9500 |
C7—H7A | 0.9900 | C19—C20 | 1.406 (2) |
C7—H7B | 0.9900 | C19—H19 | 0.9500 |
N8—C16 | 1.4861 (14) | C20—C21 | 1.403 (2) |
O9—C9 | 1.4430 (16) | C20—H20 | 0.9500 |
O9—H9 | 0.8400 | C21—C22 | 1.4151 (19) |
C9—C10 | 1.5121 (16) | C21—H21 | 0.9500 |
C9—H9C | 1.0000 | C22—H22 | 0.9500 |
N8—C1—C2 | 107.58 (10) | O9—C9—H9C | 107.8 |
N8—C1—C7 | 105.46 (9) | C10—C9—H9C | 107.8 |
C2—C1—C7 | 111.25 (10) | C2—C9—H9C | 107.8 |
N8—C1—H1 | 110.8 | C15—C10—C11 | 120.07 (11) |
C2—C1—H1 | 110.8 | C15—C10—C9 | 121.20 (12) |
C7—C1—H1 | 110.8 | C11—C10—C9 | 118.73 (12) |
C3—C2—C1 | 108.74 (9) | C12—C11—C10 | 120.33 (13) |
C3—C2—C9 | 112.33 (10) | C12—C11—H11 | 119.8 |
C1—C2—C9 | 111.67 (9) | C10—C11—H11 | 119.8 |
C3—C2—H2 | 108.0 | C11—C12—C13 | 119.32 (13) |
C1—C2—H2 | 108.0 | C11—C12—H12 | 120.3 |
C9—C2—H2 | 108.0 | C13—C12—H12 | 120.3 |
O3—C3—C4 | 121.66 (11) | C12—C13—C14 | 120.62 (11) |
O3—C3—C2 | 121.38 (12) | C12—C13—H13 | 119.7 |
C4—C3—C2 | 116.94 (10) | C14—C13—H13 | 119.7 |
C3—C4—C5 | 109.85 (10) | C15—C14—C13 | 120.37 (13) |
C3—C4—H4A | 109.7 | C15—C14—H14 | 119.8 |
C5—C4—H4A | 109.7 | C13—C14—H14 | 119.8 |
C3—C4—H4B | 109.7 | C14—C15—C10 | 119.27 (13) |
C5—C4—H4B | 109.7 | C14—C15—H15 | 120.4 |
H4A—C4—H4B | 108.2 | C10—C15—H15 | 120.4 |
N8—C5—C4 | 108.25 (9) | N8—C16—C17 | 111.62 (9) |
N8—C5—C6 | 105.38 (10) | N8—C16—H16A | 109.3 |
C4—C5—C6 | 109.80 (10) | C17—C16—H16A | 109.3 |
N8—C5—H5 | 111.1 | N8—C16—H16B | 109.3 |
C4—C5—H5 | 111.1 | C17—C16—H16B | 109.3 |
C6—C5—H5 | 111.1 | H16A—C16—H16B | 108.0 |
C5—C6—C7 | 103.74 (10) | C22—C17—C18 | 118.94 (12) |
C5—C6—H6A | 111.0 | C22—C17—C16 | 120.10 (12) |
C7—C6—H6A | 111.0 | C18—C17—C16 | 120.96 (12) |
C5—C6—H6B | 111.0 | C19—C18—C17 | 120.96 (13) |
C7—C6—H6B | 111.0 | C19—C18—H18 | 119.5 |
H6A—C6—H6B | 109.0 | C17—C18—H18 | 119.5 |
C1—C7—C6 | 104.36 (10) | C20—C19—C18 | 119.68 (13) |
C1—C7—H7A | 110.9 | C20—C19—H19 | 120.2 |
C6—C7—H7A | 110.9 | C18—C19—H19 | 120.2 |
C1—C7—H7B | 110.9 | C21—C20—C19 | 119.74 (12) |
C6—C7—H7B | 110.9 | C21—C20—H20 | 120.1 |
H7A—C7—H7B | 108.9 | C19—C20—H20 | 120.1 |
C16—N8—C1 | 112.14 (10) | C20—C21—C22 | 120.66 (13) |
C16—N8—C5 | 109.34 (9) | C20—C21—H21 | 119.7 |
C1—N8—C5 | 101.69 (9) | C22—C21—H21 | 119.7 |
C9—O9—H9 | 109.5 | C17—C22—C21 | 120.02 (13) |
O9—C9—C10 | 109.26 (11) | C17—C22—H22 | 120.0 |
O9—C9—C2 | 112.65 (9) | C21—C22—H22 | 120.0 |
C10—C9—C2 | 111.47 (10) |
D—H···A | D—H | H···A | D···A | D—H···A |
O9—H9···N8 | 0.84 | 1.99 | 2.7280 (13) | 146 |
C6—H6B···O3i | 0.99 | 2.61 | 3.3414 (15) | 131 |
C7—H7A···O3i | 0.99 | 2.52 | 3.2954 (15) | 135 |
C16—H16A···O3i | 0.99 | 2.60 | 3.5846 (16) | 173 |
Symmetry code: (i) −x+2, y+1/2, −z+1/2. |
Experimental details
Crystal data | |
Chemical formula | C21H23NO2 |
Mr | 321.40 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 100 |
a, b, c (Å) | 5.9354 (1), 13.3091 (2), 22.1511 (3) |
V (Å3) | 1749.82 (5) |
Z | 4 |
Radiation type | Cu Kα |
µ (mm−1) | 0.61 |
Crystal size (mm) | 0.65 × 0.25 × 0.19 |
Data collection | |
Diffractometer | Oxford Diffraction SuperNova Dual diffractometer |
Absorption correction | Analytical (CrysAlis PRO; Agilent, 2011) |
Tmin, Tmax | 0.75, 0.89 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 32829, 3323, 3276 |
Rint | 0.026 |
(sin θ/λ)max (Å−1) | 0.622 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.027, 0.070, 1.18 |
No. of reflections | 3323 |
No. of parameters | 218 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.16, −0.16 |
Absolute structure | Flack (1983), 1257 Friedel pairs |
Absolute structure parameter | 0.12 (18) |
Computer programs: CrysAlis PRO (Agilent, 2011), SHELXD (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and pyMOL (DeLano, 2002).
D—H···A | D—H | H···A | D···A | D—H···A |
O9—H9···N8 | 0.84 | 1.99 | 2.7280 (13) | 146 |
C6—H6B···O3i | 0.99 | 2.61 | 3.3414 (15) | 131 |
C7—H7A···O3i | 0.99 | 2.52 | 3.2954 (15) | 135 |
C16—H16A···O3i | 0.99 | 2.60 | 3.5846 (16) | 173 |
Symmetry code: (i) −x+2, y+1/2, −z+1/2. |
Acknowledgements
This work was supported in part by the University of Bialystok (BST-125), the Polish Ministry of Science and Higher Education (grant No. N N204 546939), the Intramural Research Program of the NIH, National Cancer Institute, Center for Cancer Research, and with Federal funds from the National Cancer Institute, National Institutes of Health, under contract HHSN2612008000001E.
References
Agilent (2011). CrysAlis PRO. Agilent Technologies, Yarnton, England. Google Scholar
DeLano, W. L. (2002). The pyMOL Molecular Graphics System. DeLano Scientific, San Carlos, CA, USA. Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Lazny, R. & Nodzewska, A. (2003). Tetrahedron Lett. 44, 2441–2444. Web of Science CrossRef CAS Google Scholar
Lazny, R., Nodzewska, A. & Tomczuk, I. (2011). Tetrahedron Lett. 52, 5680–5683. Web of Science CrossRef CAS Google Scholar
Lazny, R., Sienkiewicz, M. & Bräse, S. (2001). Tetrahedron, 57, 5825–5832. Web of Science CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sienkiewicz, M., Wilkaniec, U. & Lazny, R. (2009). Tetrahedron Lett. 50, 7196–7198. Web of Science CrossRef CAS Google Scholar
Singh, S. (2000). Chem. Rev. 100, 925–1024. Web of Science CrossRef PubMed CAS Google Scholar
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Tropane (8-methyl-8-azabicyclo[3.2.1]octane) and nortropane (8-azabicyclo[3.2.1]octane) are known scaffolds of numerous natural alkaloids, many of which demonstrate a range of biological activities. Many synthetic derivatives and unnatural analogues of tropane alkaloids have been synthesized and studied as potential agrochemically or pharmaceutically useful agents (Singh, 2000). Diastereomerically and enantimerically pure aldols of tropinone were used as key intermediates in stereoselective synthesis of unnatural enantiomer of cocaine (ent-cocaine), knightinol, alkaloid KD–B and ferrugine (Sienkiewicz et al., 2009). Stereoselective syntheses of nortropinone aldols (Lazny & Nodzewska, 2003; Lazny et al., 2001) is more complicated and remains a challenge. Therefore synthetically equivalent N-benzylnortropinone aldols may open a route to synthetic availability of nor-analogues of potential pharmaceutical importance. Knowledge of the structure and reactivity of the N-benzyl analogues of tropanes is also used for modeling reactivity of nortropanes anchored through nitrogen on commonly used solid-phase supports with benzyl derived linkers. The solid-phase immobilization and subsequent transformations are typically used in combinatorial approaches to preparation of libraries of potentially bioactive substances.
The studied N-benzyl compound was prepared by a procedure analogous to method known for N-methyl aldols. The synthetic procedure gave a racemic mixture, however homochiral crystals were formed spontaneously. An enantiomorphic crystal was picked at random.
The crystal structure of the title compound contains one molecule in the asymmetric unit (Fig. 1). The Flack parameter is equal to 0.12 (18) for the crystals containing (2R)-8-benzyl-2-[(S)-hydroxy(phenyl)methyl]-8-azabicyclo[3.2.1] octan-3-one enantiomer. The intramolecular hydrogen bond is formed between hydroxyl group and heterocyclic nitrogen atom from the azabicyclo[3.2.1]octan-3-one system. The carbonyl oxygen atom is located near equatorial hydrogen atoms of C6 and C7, as well as, the H16A atom. Intra- and intermolecular interactions are shown in Fig. 2 and summarized in Table 1.