organic compounds
The title compound, C21H25NO6, prepared using a procedure for the synthesis of enantiomerically pure 5-oxo-α-amino acids, has three fully extended substituents on the central α-C atom of the amino acid. Relatively weak N—HO=C hydrogen bonds (NO > 3 Å) link the molecules into chains.
Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536802023231/bt6219sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536802023231/bt6219Isup2.hkl |
CCDC reference: 203015
Computing details top
Data collection: DIF4 (Stoe & Cie, 1988); cell refinement: DIF4; data reduction: local programs; program(s) used to solve structure: SHELXTL (Sheldrick, 2001); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and local programs.
Benzyl (2S)-2-tert-butoxycarbonylamino-5-(2-furyl)-5-oxopentanoate top
Crystal data top
C21H25NO6 | Z = 1 |
Mr = 387.42 | F(000) = 206 |
Triclinic, P1 | Dx = 1.266 Mg m−3 |
a = 5.200 (2) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 10.132 (4) Å | Cell parameters from 32 reflections |
c = 10.768 (4) Å | θ = 10.7–12.5° |
α = 65.66 (2)° | µ = 0.09 mm−1 |
β = 83.87 (2)° | T = 160 K |
γ = 79.63 (3)° | Plate, colourless |
V = 508.1 (3) Å3 | 0.56 × 0.52 × 0.20 mm |
Data collection top
Stoe–Siemens four-circle diffractometer | Rint = 0.038 |
Radiation source: fine-focus sealed tube | θmax = 25.0°, θmin = 3.6° |
Graphite monochromator | h = −6→6 |
ω/θ scans with on–line profile fitting (Clegg, 1981) | k = −10→12 |
1795 measured reflections | l = −5→12 |
1786 independent reflections | 5 standard reflections every 60 min |
1729 reflections with I > 2σ(I) | intensity decay: 2% |
Refinement top
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) = 0.081 | w = 1/[σ2(Fo2) + (0.0533P)2 + 0.0741P] where P = (Fo2 + 2Fc2)/3 |
S = 1.05 | (Δ/σ)max < 0.001 |
1786 reflections | Δρmax = 0.18 e Å−3 |
257 parameters | Δρmin = −0.23 e Å−3 |
3 restraints | Extinction correction: SHELXTL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.031 (8) |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
x | y | z | Uiso*/Ueq | ||
C1 | 0.6528 (5) | 0.3489 (4) | −0.0269 (3) | 0.0422 (7) | |
H1A | 0.5683 | 0.3256 | −0.0909 | 0.063* | |
H1B | 0.7823 | 0.2652 | 0.0237 | 0.063* | |
H1C | 0.7400 | 0.4349 | −0.0775 | 0.063* | |
C2 | 0.3166 (5) | 0.2478 (3) | 0.1555 (3) | 0.0373 (6) | |
H2A | 0.2236 | 0.2239 | 0.0947 | 0.056* | |
H2B | 0.1920 | 0.2688 | 0.2223 | 0.056* | |
H2C | 0.4492 | 0.1645 | 0.2031 | 0.056* | |
C3 | 0.2547 (5) | 0.5159 (3) | −0.0034 (3) | 0.0348 (6) | |
H3A | 0.1082 | 0.5264 | 0.0588 | 0.052* | |
H3B | 0.1889 | 0.5052 | −0.0802 | 0.052* | |
H3C | 0.3419 | 0.6029 | −0.0376 | 0.052* | |
C4 | 0.4482 (4) | 0.3812 (3) | 0.0723 (2) | 0.0279 (5) | |
C5 | 0.4911 (4) | 0.4462 (3) | 0.2637 (2) | 0.0248 (5) | |
C6 | 0.5796 (4) | 0.5161 (2) | 0.4413 (2) | 0.0232 (5) | |
H6 | 0.4254 | 0.4686 | 0.4919 | 0.028* | |
C7 | 0.4958 (4) | 0.6809 (3) | 0.3786 (2) | 0.0252 (5) | |
C8 | 0.1986 (5) | 0.8740 (3) | 0.4062 (3) | 0.0331 (5) | |
H8A | 0.1423 | 0.9138 | 0.3110 | 0.040* | |
H8B | 0.3386 | 0.9270 | 0.4093 | 0.040* | |
C9 | −0.0295 (5) | 0.8945 (3) | 0.4985 (3) | 0.0290 (5) | |
C10 | −0.0795 (6) | 0.7840 (3) | 0.6234 (3) | 0.0374 (6) | |
H10 | 0.0329 | 0.6926 | 0.6538 | 0.045* | |
C11 | −0.2949 (7) | 0.8074 (3) | 0.7041 (3) | 0.0523 (8) | |
H11 | −0.3289 | 0.7314 | 0.7896 | 0.063* | |
C12 | −0.4602 (6) | 0.9397 (4) | 0.6614 (3) | 0.0486 (7) | |
H12 | −0.6096 | 0.9539 | 0.7161 | 0.058* | |
C13 | −0.4065 (6) | 1.0510 (3) | 0.5388 (3) | 0.0431 (7) | |
H13 | −0.5160 | 1.1433 | 0.5101 | 0.052* | |
C14 | −0.1920 (5) | 1.0283 (3) | 0.4572 (3) | 0.0357 (6) | |
H14 | −0.1566 | 1.1052 | 0.3725 | 0.043* | |
C15 | 0.7929 (4) | 0.4803 (2) | 0.5433 (2) | 0.0246 (5) | |
H15A | 0.9520 | 0.5197 | 0.4933 | 0.030* | |
H15B | 0.7319 | 0.5287 | 0.6066 | 0.030* | |
C16 | 0.8605 (4) | 0.3166 (3) | 0.6246 (2) | 0.0277 (5) | |
H16A | 0.7005 | 0.2774 | 0.6734 | 0.033* | |
H16B | 0.9228 | 0.2687 | 0.5610 | 0.033* | |
C17 | 1.0680 (4) | 0.2785 (3) | 0.7270 (2) | 0.0257 (5) | |
C18 | 1.0941 (4) | 0.1309 (3) | 0.8343 (2) | 0.0267 (5) | |
C19 | 0.9463 (5) | 0.0228 (3) | 0.8754 (3) | 0.0414 (6) | |
H19 | 0.7922 | 0.0227 | 0.8353 | 0.050* | |
C20 | 1.0712 (7) | −0.0924 (3) | 0.9926 (3) | 0.0515 (8) | |
H20 | 1.0154 | −0.1842 | 1.0462 | 0.062* | |
C21 | 1.2811 (6) | −0.0447 (3) | 1.0113 (3) | 0.0479 (7) | |
H21 | 1.4007 | −0.0997 | 1.0819 | 0.058* | |
N | 0.6703 (3) | 0.4612 (2) | 0.3367 (2) | 0.0260 (4) | |
H0 | 0.8386 | 0.4382 | 0.3213 | 0.031* | |
O1 | 0.6072 (3) | 0.41020 (19) | 0.16225 (16) | 0.0299 (4) | |
O2 | 0.2558 (3) | 0.4606 (2) | 0.28993 (18) | 0.0373 (5) | |
O3 | 0.5954 (4) | 0.7660 (2) | 0.27926 (19) | 0.0424 (5) | |
O4 | 0.2950 (3) | 0.71995 (17) | 0.45144 (17) | 0.0294 (4) | |
O5 | 1.2087 (3) | 0.3663 (2) | 0.72065 (18) | 0.0362 (4) | |
O6 | 1.3017 (4) | 0.0911 (2) | 0.91733 (18) | 0.0387 (4) |
Atomic displacement parameters (Å2) top
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0274 (12) | 0.076 (2) | 0.0448 (15) | −0.0088 (13) | 0.0020 (11) | −0.0461 (15) |
C2 | 0.0358 (14) | 0.0410 (14) | 0.0415 (14) | −0.0097 (11) | −0.0049 (11) | −0.0205 (12) |
C3 | 0.0298 (13) | 0.0424 (14) | 0.0342 (13) | −0.0092 (11) | −0.0038 (10) | −0.0153 (11) |
C4 | 0.0206 (11) | 0.0453 (14) | 0.0294 (11) | −0.0089 (9) | −0.0019 (9) | −0.0249 (10) |
C5 | 0.0178 (10) | 0.0354 (11) | 0.0264 (11) | −0.0064 (9) | 0.0019 (8) | −0.0171 (9) |
C6 | 0.0173 (10) | 0.0349 (12) | 0.0225 (10) | −0.0040 (9) | 0.0016 (8) | −0.0171 (9) |
C7 | 0.0176 (10) | 0.0375 (12) | 0.0217 (11) | −0.0028 (9) | −0.0013 (8) | −0.0135 (10) |
C8 | 0.0332 (13) | 0.0271 (12) | 0.0358 (13) | −0.0028 (10) | 0.0036 (10) | −0.0112 (10) |
C9 | 0.0282 (12) | 0.0297 (11) | 0.0368 (13) | −0.0075 (9) | −0.0019 (10) | −0.0195 (10) |
C10 | 0.0434 (15) | 0.0295 (12) | 0.0404 (14) | −0.0042 (11) | 0.0110 (12) | −0.0187 (11) |
C11 | 0.064 (2) | 0.0439 (16) | 0.0527 (18) | −0.0187 (15) | 0.0267 (15) | −0.0254 (14) |
C12 | 0.0401 (16) | 0.0602 (19) | 0.0630 (19) | −0.0119 (13) | 0.0160 (14) | −0.0446 (16) |
C13 | 0.0344 (13) | 0.0440 (15) | 0.0617 (18) | 0.0033 (11) | −0.0031 (12) | −0.0354 (14) |
C14 | 0.0312 (13) | 0.0350 (13) | 0.0435 (14) | −0.0012 (10) | −0.0046 (11) | −0.0192 (11) |
C15 | 0.0225 (11) | 0.0296 (11) | 0.0261 (11) | −0.0035 (8) | −0.0030 (8) | −0.0151 (9) |
C16 | 0.0231 (11) | 0.0299 (12) | 0.0336 (12) | −0.0028 (9) | −0.0060 (9) | −0.0156 (10) |
C17 | 0.0184 (10) | 0.0350 (12) | 0.0261 (11) | −0.0017 (9) | 0.0023 (8) | −0.0165 (9) |
C18 | 0.0214 (11) | 0.0359 (12) | 0.0260 (11) | 0.0024 (9) | −0.0005 (8) | −0.0183 (10) |
C19 | 0.0351 (14) | 0.0320 (13) | 0.0527 (16) | −0.0025 (11) | 0.0016 (12) | −0.0144 (12) |
C20 | 0.063 (2) | 0.0321 (14) | 0.0472 (16) | −0.0042 (13) | 0.0079 (14) | −0.0078 (12) |
C21 | 0.0576 (19) | 0.0458 (16) | 0.0319 (14) | 0.0062 (14) | −0.0070 (13) | −0.0115 (12) |
N | 0.0149 (9) | 0.0411 (10) | 0.0288 (9) | −0.0019 (8) | 0.0009 (7) | −0.0223 (8) |
O1 | 0.0168 (8) | 0.0527 (10) | 0.0334 (9) | −0.0070 (7) | 0.0005 (6) | −0.0299 (8) |
O2 | 0.0166 (8) | 0.0695 (13) | 0.0406 (10) | −0.0080 (8) | 0.0026 (7) | −0.0371 (10) |
O3 | 0.0360 (10) | 0.0421 (10) | 0.0318 (10) | 0.0010 (8) | 0.0079 (8) | −0.0025 (8) |
O4 | 0.0272 (9) | 0.0276 (8) | 0.0335 (9) | −0.0054 (7) | 0.0078 (7) | −0.0140 (7) |
O5 | 0.0311 (9) | 0.0453 (10) | 0.0338 (9) | −0.0149 (8) | −0.0068 (7) | −0.0125 (8) |
O6 | 0.0393 (10) | 0.0450 (11) | 0.0300 (9) | 0.0016 (8) | −0.0121 (7) | −0.0138 (8) |
Geometric parameters (Å, º) top
C1—H1A | 0.980 | C9—C14 | 1.387 (4) |
C1—H1B | 0.980 | C10—H10 | 0.950 |
C1—H1C | 0.980 | C10—C11 | 1.390 (4) |
C1—C4 | 1.516 (3) | C11—H11 | 0.950 |
C2—H2A | 0.980 | C11—C12 | 1.382 (5) |
C2—H2B | 0.980 | C12—H12 | 0.950 |
C2—H2C | 0.980 | C12—C13 | 1.378 (5) |
C2—C4 | 1.517 (4) | C13—H13 | 0.950 |
C3—H3A | 0.980 | C13—C14 | 1.390 (4) |
C3—H3B | 0.980 | C14—H14 | 0.950 |
C3—H3C | 0.980 | C15—H15A | 0.990 |
C3—C4 | 1.518 (4) | C15—H15B | 0.990 |
C4—O1 | 1.484 (3) | C15—C16 | 1.516 (3) |
C5—N | 1.347 (3) | C16—H16A | 0.990 |
C5—O1 | 1.342 (3) | C16—H16B | 0.990 |
C5—O2 | 1.222 (3) | C16—C17 | 1.510 (3) |
C6—H6 | 1.000 | C17—C18 | 1.458 (3) |
C6—C7 | 1.519 (3) | C17—O5 | 1.227 (3) |
C6—C15 | 1.535 (3) | C18—C19 | 1.348 (4) |
C6—N | 1.452 (3) | C18—O6 | 1.371 (3) |
C7—O3 | 1.199 (3) | C19—H19 | 0.950 |
C7—O4 | 1.340 (3) | C19—C20 | 1.436 (4) |
C8—H8A | 0.990 | C20—H20 | 0.950 |
C8—H8B | 0.990 | C20—C21 | 1.335 (5) |
C8—C9 | 1.506 (4) | C21—H21 | 0.950 |
C8—O4 | 1.438 (3) | C21—O6 | 1.346 (4) |
C9—C10 | 1.385 (4) | N—H0 | 0.880 |
H1A—C1—H1B | 109.5 | H10—C10—C11 | 120.1 |
H1A—C1—H1C | 109.5 | C10—C11—H11 | 119.6 |
H1A—C1—C4 | 109.5 | C10—C11—C12 | 120.8 (3) |
H1B—C1—H1C | 109.5 | H11—C11—C12 | 119.6 |
H1B—C1—C4 | 109.5 | C11—C12—H12 | 120.3 |
H1C—C1—C4 | 109.5 | C11—C12—C13 | 119.4 (3) |
H2A—C2—H2B | 109.5 | H12—C12—C13 | 120.3 |
H2A—C2—H2C | 109.5 | C12—C13—H13 | 120.0 |
H2A—C2—C4 | 109.5 | C12—C13—C14 | 120.1 (3) |
H2B—C2—H2C | 109.5 | H13—C13—C14 | 120.0 |
H2B—C2—C4 | 109.5 | C9—C14—C13 | 120.5 (3) |
H2C—C2—C4 | 109.5 | C9—C14—H14 | 119.7 |
H3A—C3—H3B | 109.5 | C13—C14—H14 | 119.7 |
H3A—C3—H3C | 109.5 | C6—C15—H15A | 109.3 |
H3A—C3—C4 | 109.5 | C6—C15—H15B | 109.3 |
H3B—C3—H3C | 109.5 | C6—C15—C16 | 111.75 (18) |
H3B—C3—C4 | 109.5 | H15A—C15—H15B | 107.9 |
H3C—C3—C4 | 109.5 | H15A—C15—C16 | 109.3 |
C1—C4—C2 | 110.5 (2) | H15B—C15—C16 | 109.3 |
C1—C4—C3 | 110.2 (2) | C15—C16—H16A | 109.0 |
C1—C4—O1 | 102.53 (17) | C15—C16—H16B | 109.0 |
C2—C4—C3 | 112.7 (2) | C15—C16—C17 | 112.83 (19) |
C2—C4—O1 | 109.59 (19) | H16A—C16—H16B | 107.8 |
C3—C4—O1 | 110.82 (19) | H16A—C16—C17 | 109.0 |
N—C5—O1 | 110.72 (18) | H16B—C16—C17 | 109.0 |
N—C5—O2 | 123.8 (2) | C16—C17—C18 | 116.5 (2) |
O1—C5—O2 | 125.5 (2) | C16—C17—O5 | 122.1 (2) |
H6—C6—C7 | 108.6 | C18—C17—O5 | 121.3 (2) |
H6—C6—C15 | 108.6 | C17—C18—C19 | 133.1 (2) |
H6—C6—N | 108.6 | C17—C18—O6 | 116.3 (2) |
C7—C6—C15 | 108.57 (17) | C19—C18—O6 | 110.6 (2) |
C7—C6—N | 111.01 (18) | C18—C19—H19 | 127.3 |
C15—C6—N | 111.47 (17) | C18—C19—C20 | 105.4 (3) |
C6—C7—O3 | 125.6 (2) | H19—C19—C20 | 127.3 |
C6—C7—O4 | 110.43 (18) | C19—C20—H20 | 126.8 |
O3—C7—O4 | 123.9 (2) | C19—C20—C21 | 106.4 (3) |
H8A—C8—H8B | 108.4 | H20—C20—C21 | 126.8 |
H8A—C8—C9 | 110.0 | C20—C21—H21 | 124.3 |
H8A—C8—O4 | 110.0 | C20—C21—O6 | 111.4 (3) |
H8B—C8—C9 | 110.0 | H21—C21—O6 | 124.3 |
H8B—C8—O4 | 110.0 | C5—N—C6 | 118.48 (17) |
C9—C8—O4 | 108.53 (19) | C5—N—H0 | 120.8 |
C8—C9—C10 | 121.9 (2) | C6—N—H0 | 120.8 |
C8—C9—C14 | 118.8 (2) | C4—O1—C5 | 120.18 (17) |
C10—C9—C14 | 119.3 (2) | C7—O4—C8 | 116.75 (18) |
C9—C10—H10 | 120.1 | C18—O6—C21 | 106.2 (2) |
C9—C10—C11 | 119.7 (3) | ||
C15—C6—C7—O4 | −91.0 (2) | C8—C9—C10—C11 | −179.0 (3) |
N—C6—C7—O4 | 146.13 (18) | C14—C9—C10—C11 | 1.5 (4) |
C7—C6—C15—C16 | 172.11 (18) | C9—C10—C11—C12 | −0.1 (5) |
N—C6—C15—C16 | −65.3 (2) | C10—C11—C12—C13 | −1.7 (5) |
C7—C6—N—C5 | −77.3 (3) | C11—C12—C13—C14 | 1.9 (4) |
C15—C6—N—C5 | 161.5 (2) | C8—C9—C14—C13 | 179.2 (2) |
C6—C7—O4—C8 | 178.39 (19) | C10—C9—C14—C13 | −1.3 (4) |
C9—C8—O4—C7 | 178.54 (19) | C12—C13—C14—C9 | −0.5 (4) |
O4—C8—C9—C10 | 15.3 (3) | C15—C16—C17—O5 | −16.8 (3) |
O4—C8—C9—C14 | −165.2 (2) | O5—C17—C18—C19 | 169.3 (3) |
C6—C15—C16—C17 | −179.35 (18) | O5—C17—C18—O6 | −7.1 (3) |
C15—C16—C17—C18 | 163.45 (19) | C17—C18—C19—C20 | −176.4 (2) |
C16—C17—C18—C19 | −10.9 (4) | O6—C18—C19—C20 | 0.1 (3) |
C16—C17—C18—O6 | 172.68 (18) | C18—C19—C20—C21 | −0.3 (3) |
O1—C5—N—C6 | 173.1 (2) | C19—C20—C21—O6 | 0.5 (4) |
N—C5—O1—C4 | 177.16 (19) | O2—C5—N—C6 | −8.3 (4) |
C1—C4—O1—C5 | 178.8 (2) | O2—C5—O1—C4 | −1.3 (4) |
C2—C4—O1—C5 | −63.7 (3) | O3—C7—O4—C8 | −0.6 (3) |
C3—C4—O1—C5 | 61.2 (3) | C20—C21—O6—C18 | −0.4 (3) |
N—C6—C7—O3 | −34.9 (3) | C17—C18—O6—C21 | 177.3 (2) |
C15—C6—C7—O3 | 87.9 (3) | C19—C18—O6—C21 | 0.2 (3) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N—H0···O2i | 0.88 | 2.20 | 3.032 (3) | 158 |
Symmetry code: (i) x+1, y, z. |