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The title compound, C
42H
46N
2O
6, crystallizes with half a molecule in the asymmetric unit, the molecule being centrosymmetric. The ethyl ester and
N-formyl side chains attached to the C
α atom of the molecule adopt a
trans and
cis configuration, respectively. The crystal structure is stabilized by C—H
O, N—H
O and C—H
π interactions and herring-bone-type packing is observed.
Supporting information
CCDC reference: 197486
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.004 Å
- R factor = 0.067
- wR factor = 0.179
- Data-to-parameter ratio = 20.1
checkCIF results
No syntax errors found
ADDSYM reports no extra symmetry
General Notes
ABSTY_01 Extra text has been found in the _exptl_absorpt_correction_type
field, which should be only a single keyword. A literature
citation should be included in the _exptl_absorpt_process_details
field.
The title unusual macrocyclic cyclophane-based α-amino acid derivative has been synthesized by coupling of ethyl isocyanoacetate with 1,2-bis(4-bromomethylphenyl)ethane under phase-tranfer-catalysis conditions.
The H atoms were fixed geometrically at calculated positions.
Data collection: SMART (Bruker, 1999); cell refinement: SMART; data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997).
Macrocyclic cyclophane-based unusual amino acid
top
Crystal data top
C42H46N2O6 | Dx = 1.182 Mg m−3 |
Mr = 674.81 | Mo Kα radiation, λ = 0.71073 Å |
Orthorhombic, Pbca | Cell parameters from 4538 reflections |
a = 15.890 (2) Å | θ = 1.9–28.0° |
b = 11.2944 (16) Å | µ = 0.08 mm−1 |
c = 21.125 (3) Å | T = 293 K |
V = 3791.1 (9) Å3 | Rectangular, colourless |
Z = 4 | 0.54 × 0.45 × 0.45 mm |
F(000) = 1440 | |
Data collection top
CCD area detector diffractometer | 3019 reflections with I > 2σ(I) |
Radiation source: sealed tube | Rint = 0.032 |
Graphite monochromator | θmax = 28.0°, θmin = 1.9° |
ϕ and ω scans | h = −20→20 |
31175 measured reflections | k = −12→14 |
4538 independent reflections | l = −27→27 |
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)] = 0.067 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.179 | H-atom parameters constrained |
S = 1.09 | w = 1/[σ2(Fo2) + (0.0764P)2 + 0.779P] where P = (Fo2 + 2Fc2)/3 |
4538 reflections | (Δ/σ)max < 0.001 |
226 parameters | Δρmax = 0.19 e Å−3 |
0 restraints | Δρmin = −0.14 e Å−3 |
Crystal data top
C42H46N2O6 | V = 3791.1 (9) Å3 |
Mr = 674.81 | Z = 4 |
Orthorhombic, Pbca | Mo Kα radiation |
a = 15.890 (2) Å | µ = 0.08 mm−1 |
b = 11.2944 (16) Å | T = 293 K |
c = 21.125 (3) Å | 0.54 × 0.45 × 0.45 mm |
Data collection top
CCD area detector diffractometer | 3019 reflections with I > 2σ(I) |
31175 measured reflections | Rint = 0.032 |
4538 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.067 | 0 restraints |
wR(F2) = 0.179 | H-atom parameters constrained |
S = 1.09 | Δρmax = 0.19 e Å−3 |
4538 reflections | Δρmin = −0.14 e Å−3 |
226 parameters | |
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 | |
N1 | 0.12073 (9) | 0.05376 (13) | 0.45160 (7) | 0.0529 (4) | |
H1 | 0.0770 | 0.0170 | 0.4654 | 0.063* | |
C1 | 0.11952 (11) | 0.18242 (16) | 0.45533 (9) | 0.0516 (5) | |
C2 | 0.12312 (13) | 0.23942 (19) | 0.38852 (11) | 0.0654 (6) | |
H2A | 0.1239 | 0.3249 | 0.3931 | 0.078* | |
H2B | 0.1752 | 0.2160 | 0.3681 | 0.078* | |
C3 | 0.05030 (14) | 0.2053 (2) | 0.34661 (10) | 0.0641 (6) | |
C4 | −0.02391 (17) | 0.2704 (2) | 0.34598 (13) | 0.0832 (7) | |
H4 | −0.0266 | 0.3403 | 0.3691 | 0.100* | |
C5 | −0.09327 (18) | 0.2349 (3) | 0.31245 (13) | 0.0890 (8) | |
H5 | −0.1418 | 0.2808 | 0.3139 | 0.107* | |
C6 | −0.09281 (16) | 0.1339 (3) | 0.27705 (10) | 0.0769 (7) | |
C7 | −0.01896 (17) | 0.0703 (3) | 0.27505 (11) | 0.0830 (7) | |
H7 | −0.0162 | 0.0021 | 0.2504 | 0.100* | |
C8 | 0.05177 (16) | 0.1060 (2) | 0.30918 (11) | 0.0761 (7) | |
H8 | 0.1009 | 0.0615 | 0.3065 | 0.091* | |
C9 | 0.17199 (19) | −0.0926 (3) | 0.75679 (11) | 0.0957 (9) | |
H9A | 0.1676 | −0.1146 | 0.8011 | 0.115* | |
H9B | 0.2197 | −0.1349 | 0.7392 | 0.115* | |
C10 | 0.18968 (19) | 0.0372 (3) | 0.75309 (12) | 0.0963 (9) | |
H10A | 0.2435 | 0.0527 | 0.7732 | 0.116* | |
H10B | 0.1469 | 0.0791 | 0.7770 | 0.116* | |
C11 | 0.19194 (14) | 0.0873 (2) | 0.68636 (10) | 0.0734 (6) | |
C12 | 0.15145 (15) | 0.1912 (3) | 0.67162 (12) | 0.0813 (7) | |
H12 | 0.1223 | 0.2313 | 0.7032 | 0.098* | |
C13 | 0.15277 (14) | 0.2374 (2) | 0.61178 (12) | 0.0725 (6) | |
H13 | 0.1247 | 0.3080 | 0.6038 | 0.087* | |
C14 | 0.19491 (12) | 0.18159 (18) | 0.56274 (10) | 0.0589 (5) | |
C15 | 0.23656 (14) | 0.0784 (2) | 0.57747 (11) | 0.0706 (6) | |
H15 | 0.2662 | 0.0387 | 0.5459 | 0.085* | |
C16 | 0.23534 (15) | 0.0322 (2) | 0.63824 (12) | 0.0776 (7) | |
H16 | 0.2644 | −0.0375 | 0.6467 | 0.093* | |
C17 | 0.19260 (12) | 0.23013 (18) | 0.49639 (11) | 0.0624 (5) | |
H17A | 0.2454 | 0.2113 | 0.4756 | 0.075* | |
H17B | 0.1882 | 0.3157 | 0.4986 | 0.075* | |
C18 | 0.18303 (14) | −0.01222 (19) | 0.42894 (11) | 0.0675 (6) | |
H18 | 0.1744 | −0.0937 | 0.4290 | 0.081* | |
O18 | 0.24981 (10) | 0.02203 (16) | 0.40823 (9) | 0.0904 (6) | |
C19 | 0.03523 (11) | 0.21237 (16) | 0.48647 (9) | 0.0516 (5) | |
O19 | −0.01518 (8) | 0.14112 (12) | 0.50321 (8) | 0.0683 (4) | |
C20 | −0.05690 (14) | 0.3668 (2) | 0.51835 (15) | 0.0853 (8) | |
H20A | −0.0713 | 0.4437 | 0.5010 | 0.102* | |
H20B | −0.1002 | 0.3111 | 0.5056 | 0.102* | |
O20 | 0.02433 (8) | 0.32867 (11) | 0.49254 (7) | 0.0657 (4) | |
C21 | −0.0549 (2) | 0.3744 (4) | 0.58686 (18) | 0.1363 (14) | |
H21A | −0.1091 | 0.3988 | 0.6021 | 0.204* | |
H21B | −0.0132 | 0.4310 | 0.5996 | 0.204* | |
H21C | −0.0412 | 0.2982 | 0.6042 | 0.204* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
N1 | 0.0480 (8) | 0.0443 (9) | 0.0664 (10) | −0.0049 (7) | 0.0140 (7) | 0.0037 (7) |
C1 | 0.0457 (10) | 0.0420 (10) | 0.0672 (12) | −0.0068 (8) | 0.0099 (8) | 0.0066 (9) |
C2 | 0.0643 (12) | 0.0567 (13) | 0.0751 (14) | −0.0096 (10) | 0.0170 (11) | 0.0160 (10) |
C3 | 0.0685 (13) | 0.0634 (13) | 0.0604 (12) | −0.0023 (10) | 0.0136 (10) | 0.0150 (10) |
C4 | 0.0945 (18) | 0.0730 (16) | 0.0820 (17) | 0.0164 (14) | −0.0069 (14) | 0.0015 (13) |
C5 | 0.0901 (18) | 0.102 (2) | 0.0754 (16) | 0.0285 (16) | −0.0115 (14) | 0.0010 (15) |
C6 | 0.0813 (16) | 0.1013 (19) | 0.0482 (11) | 0.0132 (14) | 0.0040 (11) | 0.0086 (12) |
C7 | 0.0973 (18) | 0.0972 (19) | 0.0544 (13) | 0.0090 (15) | 0.0079 (12) | −0.0122 (12) |
C8 | 0.0757 (15) | 0.0891 (17) | 0.0637 (13) | 0.0122 (13) | 0.0181 (12) | 0.0037 (12) |
C9 | 0.1006 (19) | 0.137 (3) | 0.0494 (12) | 0.0148 (19) | −0.0134 (12) | 0.0044 (14) |
C10 | 0.0968 (19) | 0.133 (3) | 0.0594 (14) | 0.0046 (18) | −0.0194 (13) | −0.0209 (15) |
C11 | 0.0649 (13) | 0.0928 (18) | 0.0626 (13) | −0.0033 (12) | −0.0107 (10) | −0.0226 (12) |
C12 | 0.0713 (15) | 0.0980 (19) | 0.0747 (16) | 0.0082 (13) | −0.0072 (12) | −0.0398 (14) |
C13 | 0.0632 (13) | 0.0693 (14) | 0.0849 (16) | 0.0085 (11) | −0.0135 (12) | −0.0240 (12) |
C14 | 0.0431 (10) | 0.0562 (12) | 0.0773 (13) | −0.0076 (9) | −0.0002 (9) | −0.0105 (10) |
C15 | 0.0659 (13) | 0.0737 (15) | 0.0720 (14) | 0.0109 (11) | 0.0089 (11) | −0.0079 (12) |
C16 | 0.0784 (15) | 0.0788 (16) | 0.0755 (15) | 0.0150 (12) | −0.0034 (12) | −0.0073 (13) |
C17 | 0.0446 (10) | 0.0520 (12) | 0.0905 (15) | −0.0081 (8) | 0.0092 (10) | 0.0025 (10) |
C18 | 0.0692 (13) | 0.0550 (12) | 0.0784 (14) | 0.0039 (10) | 0.0206 (11) | 0.0017 (10) |
O18 | 0.0726 (10) | 0.0844 (12) | 0.1142 (14) | 0.0054 (8) | 0.0447 (10) | 0.0027 (10) |
C19 | 0.0458 (10) | 0.0431 (10) | 0.0659 (12) | −0.0054 (8) | 0.0047 (8) | 0.0036 (9) |
O19 | 0.0508 (8) | 0.0488 (8) | 0.1054 (11) | −0.0083 (6) | 0.0252 (7) | 0.0064 (7) |
C20 | 0.0564 (13) | 0.0576 (13) | 0.142 (3) | 0.0055 (11) | 0.0167 (14) | −0.0015 (14) |
O20 | 0.0504 (8) | 0.0432 (8) | 0.1035 (11) | −0.0021 (6) | 0.0131 (7) | −0.0011 (7) |
C21 | 0.108 (2) | 0.173 (4) | 0.128 (3) | 0.045 (2) | 0.041 (2) | −0.016 (3) |
Geometric parameters (Å, º) top
N1—C18 | 1.328 (2) | C10—H10B | 0.9700 |
N1—C1 | 1.455 (2) | C11—C16 | 1.377 (3) |
N1—H1 | 0.8600 | C11—C12 | 1.374 (4) |
C1—C19 | 1.530 (3) | C12—C13 | 1.367 (4) |
C1—C17 | 1.546 (3) | C12—H12 | 0.9300 |
C1—C2 | 1.552 (3) | C13—C14 | 1.385 (3) |
C2—C3 | 1.507 (3) | C13—H13 | 0.9300 |
C2—H2A | 0.9700 | C14—C15 | 1.376 (3) |
C2—H2B | 0.9700 | C14—C17 | 1.505 (3) |
C3—C8 | 1.372 (3) | C15—C16 | 1.386 (3) |
C3—C4 | 1.390 (3) | C15—H15 | 0.9300 |
C4—C5 | 1.370 (4) | C16—H16 | 0.9300 |
C4—H4 | 0.9300 | C17—H17A | 0.9700 |
C5—C6 | 1.364 (4) | C17—H17B | 0.9700 |
C5—H5 | 0.9300 | C18—O18 | 1.211 (2) |
C6—C7 | 1.377 (3) | C18—H18 | 0.9300 |
C6—C9i | 1.520 (4) | C19—O19 | 1.189 (2) |
C7—C8 | 1.395 (3) | C19—O20 | 1.331 (2) |
C7—H7 | 0.9300 | C20—C21 | 1.450 (4) |
C8—H8 | 0.9300 | C20—O20 | 1.466 (3) |
C9—C10 | 1.496 (4) | C20—H20A | 0.9700 |
C9—C6i | 1.520 (4) | C20—H20B | 0.9700 |
C9—H9A | 0.9700 | C21—H21A | 0.9600 |
C9—H9B | 0.9700 | C21—H21B | 0.9600 |
C10—C11 | 1.519 (4) | C21—H21C | 0.9600 |
C10—H10A | 0.9700 | | |
| | | |
C18—N1—C1 | 126.12 (16) | H10A—C10—H10B | 107.6 |
C18—N1—H1 | 116.9 | C16—C11—C12 | 117.0 (2) |
C1—N1—H1 | 116.9 | C16—C11—C10 | 121.9 (2) |
N1—C1—C19 | 104.81 (14) | C12—C11—C10 | 121.1 (2) |
N1—C1—C17 | 111.62 (16) | C13—C12—C11 | 121.9 (2) |
C19—C1—C17 | 109.83 (16) | C13—C12—H12 | 119.1 |
N1—C1—C2 | 111.36 (16) | C11—C12—H12 | 119.1 |
C19—C1—C2 | 109.35 (16) | C12—C13—C14 | 121.7 (2) |
C17—C1—C2 | 109.74 (15) | C12—C13—H13 | 119.2 |
C3—C2—C1 | 113.55 (15) | C14—C13—H13 | 119.2 |
C3—C2—H2A | 108.9 | C15—C14—C13 | 116.7 (2) |
C1—C2—H2A | 108.9 | C15—C14—C17 | 122.04 (19) |
C3—C2—H2B | 108.9 | C13—C14—C17 | 121.3 (2) |
C1—C2—H2B | 108.9 | C14—C15—C16 | 121.4 (2) |
H2A—C2—H2B | 107.7 | C14—C15—H15 | 119.3 |
C8—C3—C4 | 116.2 (2) | C16—C15—H15 | 119.3 |
C8—C3—C2 | 122.3 (2) | C11—C16—C15 | 121.4 (2) |
C4—C3—C2 | 121.4 (2) | C11—C16—H16 | 119.3 |
C5—C4—C3 | 122.2 (2) | C15—C16—H16 | 119.3 |
C5—C4—H4 | 118.9 | C14—C17—C1 | 114.43 (15) |
C3—C4—H4 | 118.9 | C14—C17—H17A | 108.7 |
C6—C5—C4 | 121.6 (2) | C1—C17—H17A | 108.7 |
C6—C5—H5 | 119.2 | C14—C17—H17B | 108.7 |
C4—C5—H5 | 119.2 | C1—C17—H17B | 108.7 |
C5—C6—C7 | 117.2 (2) | H17A—C17—H17B | 107.6 |
C5—C6—C9i | 120.7 (2) | O18—C18—N1 | 127.2 (2) |
C7—C6—C9i | 122.1 (3) | O18—C18—H18 | 116.4 |
C6—C7—C8 | 121.4 (2) | N1—C18—H18 | 116.4 |
C6—C7—H7 | 119.3 | O19—C19—O20 | 123.46 (17) |
C8—C7—H7 | 119.3 | O19—C19—C1 | 124.60 (17) |
C3—C8—C7 | 121.3 (2) | O20—C19—C1 | 111.93 (15) |
C3—C8—H8 | 119.3 | C21—C20—O20 | 111.7 (2) |
C7—C8—H8 | 119.3 | C21—C20—H20A | 109.3 |
C10—C9—C6i | 115.6 (2) | O20—C20—H20A | 109.3 |
C10—C9—H9A | 108.4 | C21—C20—H20B | 109.3 |
C6i—C9—H9A | 108.4 | O20—C20—H20B | 109.3 |
C10—C9—H9B | 108.4 | H20A—C20—H20B | 107.9 |
C6i—C9—H9B | 108.4 | C19—O20—C20 | 116.14 (15) |
H9A—C9—H9B | 107.4 | C20—C21—H21A | 109.5 |
C9—C10—C11 | 114.7 (2) | C20—C21—H21B | 109.5 |
C9—C10—H10A | 108.6 | H21A—C21—H21B | 109.5 |
C11—C10—H10A | 108.6 | C20—C21—H21C | 109.5 |
C9—C10—H10B | 108.6 | H21A—C21—H21C | 109.5 |
C11—C10—H10B | 108.6 | H21B—C21—H21C | 109.5 |
| | | |
C18—N1—C1—C19 | −178.50 (19) | C11—C12—C13—C14 | 0.1 (4) |
C18—N1—C1—C17 | −59.7 (3) | C12—C13—C14—C15 | −1.0 (3) |
C18—N1—C1—C2 | 63.4 (2) | C12—C13—C14—C17 | 177.1 (2) |
N1—C1—C2—C3 | 60.3 (2) | C13—C14—C15—C16 | 0.8 (3) |
C19—C1—C2—C3 | −55.1 (2) | C17—C14—C15—C16 | −177.4 (2) |
C17—C1—C2—C3 | −175.59 (17) | C12—C11—C16—C15 | −1.3 (4) |
C1—C2—C3—C8 | −87.9 (2) | C10—C11—C16—C15 | 179.7 (2) |
C1—C2—C3—C4 | 89.2 (2) | C14—C15—C16—C11 | 0.4 (4) |
C8—C3—C4—C5 | 3.1 (4) | C15—C14—C17—C1 | 88.0 (2) |
C2—C3—C4—C5 | −174.2 (2) | C13—C14—C17—C1 | −90.0 (2) |
C3—C4—C5—C6 | −0.8 (4) | N1—C1—C17—C14 | −56.6 (2) |
C4—C5—C6—C7 | −1.6 (4) | C19—C1—C17—C14 | 59.2 (2) |
C4—C5—C6—C9i | 176.5 (3) | C2—C1—C17—C14 | 179.43 (17) |
C5—C6—C7—C8 | 1.7 (4) | C1—N1—C18—O18 | 1.0 (4) |
C9i—C6—C7—C8 | −176.4 (2) | N1—C1—C19—O19 | 0.5 (3) |
C4—C3—C8—C7 | −2.9 (3) | C17—C1—C19—O19 | −119.6 (2) |
C2—C3—C8—C7 | 174.3 (2) | C2—C1—C19—O19 | 119.9 (2) |
C6—C7—C8—C3 | 0.7 (4) | N1—C1—C19—O20 | −179.26 (16) |
C6i—C9—C10—C11 | −53.9 (3) | C17—C1—C19—O20 | 60.7 (2) |
C9—C10—C11—C16 | −46.4 (4) | C2—C1—C19—O20 | −59.8 (2) |
C9—C10—C11—C12 | 134.5 (3) | O19—C19—O20—C20 | −3.3 (3) |
C16—C11—C12—C13 | 1.0 (4) | C1—C19—O20—C20 | 176.39 (19) |
C10—C11—C12—C13 | −179.9 (2) | C21—C20—O20—C19 | 89.2 (3) |
Symmetry code: (i) −x, −y, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O19i | 0.86 | 2.14 | 2.9272 (19) | 151 |
C21—H21A···O18ii | 0.96 | 2.42 | 3.317 (4) | 155 |
C5—H5···Cg2iii | 0.93 | 3.07 | 3.921 (1) | 153 |
Symmetry codes: (i) −x, −y, −z+1; (ii) x−1/2, −y+1/2, −z+1; (iii) −x+2, −y, −z. |
Experimental details
Crystal data |
Chemical formula | C42H46N2O6 |
Mr | 674.81 |
Crystal system, space group | Orthorhombic, Pbca |
Temperature (K) | 293 |
a, b, c (Å) | 15.890 (2), 11.2944 (16), 21.125 (3) |
V (Å3) | 3791.1 (9) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.08 |
Crystal size (mm) | 0.54 × 0.45 × 0.45 |
|
Data collection |
Diffractometer | CCD area detector diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 31175, 4538, 3019 |
Rint | 0.032 |
(sin θ/λ)max (Å−1) | 0.661 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.067, 0.179, 1.09 |
No. of reflections | 4538 |
No. of parameters | 226 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.19, −0.14 |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O19i | 0.86 | 2.14 | 2.9272 (19) | 151 |
C21—H21A···O18ii | 0.96 | 2.42 | 3.317 (4) | 155 |
C5—H5···Cg2iii | 0.93 | 3.07 | 3.921 (1) | 153 |
Symmetry codes: (i) −x, −y, −z+1; (ii) x−1/2, −y+1/2, −z+1; (iii) −x+2, −y, −z. |
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Macrocyclic molecules act as synthetic receptors in molecular recognition (Keehn & Rosenfeld, 1983). Incorporation of unusual amino acid Aib (α-aminoisobutyric acid) with a paracyclophane unit resulted in the title compound, (I) (Kotha et al., 2002). This synthesis yielded both the cis and the trans isomer. The crystal structure of the trans isomer, (I), is reported here. The compound crystallized from a mixture of HCl and petroleum ether in space group Pbca, with one half molecule in the asymmetric unit.
An ORTEP-3 diagram (Farrugia, 1997) of (I) is shown in Fig. 1. The conformation of the ethyl acetate side chain is trans [C1—C19—O20—C20 = 176.4 (2)°], while that of the N-formyl side chain is cis [C1—N1—C18—O18 = 1.0 (4)°] with respect to the Cα atom.
One half of the molecule is linked to the other half through an N—H···O hydrogen bond. Herring-bone-type of packing is stabilized by van der Waals forces, and C—H···O and C—H···π-type intermolecular interactions (Figs. 2 and 3).