tert-Butyl (2S)-2-{3-[(R)-bis­(tert-but­oxy­carbon­yl)amino]-2-oxopiperidin-1-yl}-3-methyl­butano­ate

Kangas, M.J.; Fronczek, F.R.; Watkins, S.F.

doi:10.1107/S1600536811043212

organic compounds

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ISSN: 2056-9890

Volume 67| Part 11| November 2011| Page o3057

doi:10.1107/S1600536811043212

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tert-Butyl (2S)-2-{3-[(R)-bis(tert-butoxycarbonyl)amino]-2-oxopiperidin-1-yl}-3-methylbutanoate †

Michael J. Kangas,^a Frank R. Fronczek ^a ^* and Steven F. Watkins ^a

^aDepartment of Chemistry, Louisiana State University, Baton Rouge, LA 70803-1804, USA
^*Correspondence e-mail: ffroncz@lsu.edu

(Received 13 October 2011; accepted 18 October 2011; online 29 October 2011)

The title compound, C₂₄H₄₂N₂O₇, is a chiral lactam-constrained amino acid with a six-membered ring backbone and isopropyl and tert-butyl ester side chains. The conformation of the six-membered ring can be described as a half chair, with two CH₂ C atoms lying 0.443 (1) and −0.310 (1) Å out of the best plane of the other four atoms (mean deviation = 0.042 Å). Both N atoms are sp² hybridized, lying 0.0413 (9) and 0.067 (1) Å out of the planes defined by the three C atoms bonded to them. The absolute configuration was determined, based on resonant scattering of light atoms in Cu Kα radiation.

Related literature

For synthesis and chemical interest, see: Oguz (2003 ); Oguz et al. (2001 ). For a similar structure, see: Valle et al. (1989 ). For absolute configuration parameters, see: Hooft et al. (2008 ).

Experimental

Crystal data

C₂₄H₄₂N₂O₇
M_r = 470.6
Monoclinic, C 2
a = 27.282 (3) Å
b = 9.4315 (10) Å
c = 11.5884 (10) Å
β = 110.729 (1)°
V = 2788.7 (5) Å³
Z = 4
Cu Kα radiation
μ = 0.67 mm⁻¹
T = 86 K
0.35 × 0.25 × 0.20 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2004 ) T_min = 0.800, T_max = 0.878
10823 measured reflections
4844 independent reflections
4782 reflections with I > 2σ(I)
R_int = 0.023

Refinement

R[F² > 2σ(F²)] = 0.026
wR(F²) = 0.071
S = 1.01
4844 reflections
310 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.19 e Å⁻³
Δρ_min = −0.12 e Å⁻³
Absolute structure: Flack (1983 ), 2174 Friedel pairs
Flack parameter: −0.02 (10)

Data collection: APEX2 (Bruker, 2006 ); cell refinement: APEX2; data reduction: APEX2; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811043212/pv2462sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811043212/pv2462Isup2.hkl

checkCIF report

Comment top

Title compound is a conformationally constrained amino acid analog which was designed as part of a study to understand the factors promoting β-sheet formation in brain-degenerative diseases such as Alzheimer's disease, Creutzfeldt-Jacob disease and bovine spongiform encephalopathy (Oguz et al., 2001).

In the title molecule (Fig. 1), the central six-membered ring adopts a conformation close to the C₂ half chair, with the diad axis bisecting the N1–C1 and C3–C4 bonds. Atoms C1, C2, C5 and N1 are coplanar to within a mean deviation 0.042 Å (maximum 0.0588 (10) Å for N1), the other two atoms lying alternately above and below this plane, C3 by -0.310 (1) and C4 by 0.443 (1) Å. The C5—N1—C1—C2 torsion angle, which would be zero for an ideal half chair, is -13.36 (18)°. This conformation is similar to that seen in a similar lactam-restricted analog of Boc-L-Pro-L-Leu-Gly-NH₂, which has torsion angle somewhat closer to zero, 5.6 (11)° and smaller mean deviation for these four atoms, 0.014 Å (Valle et al., 1989).

Both N atoms are sp² hybrids, with N1 lying only 0.067 (1) Å from the plane defined by C1, C5 and C16, and N2 lying 0.0413 (9) Å from the plane defined by C2, C6 and C11.

The absolute configuration based on the Flack (1983) parameter x = -0.02 (10), the Hooft parameter y = -0.05 (5), and the Hooft P2(true) value of 1.000 (Hooft et al., 2008) agrees with that of the starting materials.

Related literature top

For synthesis and chemical interest, see: Oguz (2003); Oguz et al. (2001). For a similar structure, see: Valle et al. (1989). For absolute configuration parameters, see: Hooft et al. (2008).

Experimental top

The synthesis of the title compound is detailed by Oguz (2003), who prepared a suitable single-crystal by recrystallization from hexanes.

Computing details top

Data collection: APEX2 (Bruker, 2006); cell refinement: APEX2 (Bruker, 2006); data reduction: APEX2 (Bruker, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

Fig. 1. View of the title molecule (50% probability displacement ellipsoids); H atoms are not shown for clarity.

tert-Butyl (2S)-2-{3-[(R)-bis(tert- butoxycarbonyl)amino]-2-oxopiperidin-1-yl}-3-methylbutanoate top

Crystal data top

C₂₄H₄₂N₂O₇	F(000) = 1024
M_r = 470.6	D_x = 1.121 Mg m⁻³
Monoclinic, C2	Cu Kα radiation, λ = 1.54178 Å
Hall symbol: C 2y	Cell parameters from 8306 reflections
a = 27.282 (3) Å	θ = 3.5–67.8°
b = 9.4315 (10) Å	µ = 0.67 mm⁻¹
c = 11.5884 (10) Å	T = 86 K
β = 110.729 (1)°	Fragment, colourless
V = 2788.7 (5) Å³	0.35 × 0.25 × 0.20 mm
Z = 4

Data collection top

Bruker Kappa APEXII CCD diffractometer	4844 independent reflections
Radiation source: fine-focus sealed tube	4782 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.023
ϕ and ω scans	θ_max = 68.2°, θ_min = 3.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	h = −32→32
T_min = 0.800, T_max = 0.878	k = −10→11
10823 measured reflections	l = −13→13

Refinement top

Refinement on F²	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F² > 2σ(F²)] = 0.026	w = 1/[σ²(F_o²) + (0.0441P)² + 0.6036P] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.071	(Δ/σ)_max = 0.001
S = 1.01	Δρ_max = 0.19 e Å⁻³
4844 reflections	Δρ_min = −0.12 e Å⁻³
310 parameters	Extinction correction: SHELXS97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
1 restraint	Extinction coefficient: 0.00066 (8)
0 constraints	Absolute structure: Flack (1983), 2174 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.02 (10)
Secondary atom site location: difference Fourier map

Crystal data top

C₂₄H₄₂N₂O₇	V = 2788.7 (5) Å³
M_r = 470.6	Z = 4
Monoclinic, C2	Cu Kα radiation
a = 27.282 (3) Å	µ = 0.67 mm⁻¹
b = 9.4315 (10) Å	T = 86 K
c = 11.5884 (10) Å	0.35 × 0.25 × 0.20 mm
β = 110.729 (1)°

Data collection top

Bruker Kappa APEXII CCD diffractometer	4844 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	4782 reflections with I > 2σ(I)
T_min = 0.800, T_max = 0.878	R_int = 0.023
10823 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.026	H-atom parameters constrained
wR(F²) = 0.071	Δρ_max = 0.19 e Å⁻³
S = 1.01	Δρ_min = −0.12 e Å⁻³
4844 reflections	Absolute structure: Flack (1983), 2174 Friedel pairs
310 parameters	Absolute structure parameter: −0.02 (10)
1 restraint

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
C1	0.29466 (4)	0.36747 (13)	0.72598 (11)	0.0195 (2)
C2	0.24099 (4)	0.41656 (13)	0.63587 (11)	0.0194 (2)
H2	0.2438	0.5214	0.6267	0.023*
C3	0.22473 (5)	0.35489 (14)	0.50640 (11)	0.0224 (3)
H3A	0.194	0.4069	0.4504	0.027*
H3B	0.2149	0.254	0.5075	0.027*
C4	0.27044 (5)	0.36775 (14)	0.46077 (11)	0.0225 (3)
H4A	0.26	0.3321	0.3751	0.027*
H4B	0.2809	0.4684	0.4616	0.027*
C5	0.31600 (5)	0.28143 (14)	0.54486 (11)	0.0221 (3)
H5A	0.307	0.1794	0.5335	0.026*
H5B	0.3471	0.2973	0.5212	0.026*
C6	0.20105 (4)	0.26219 (13)	0.74681 (11)	0.0191 (2)
C7	0.18475 (5)	0.14657 (13)	0.91793 (11)	0.0236 (3)
C8	0.24179 (5)	0.11115 (18)	0.98719 (13)	0.0343 (3)
H8A	0.258	0.0784	0.9288	0.051*
H8B	0.2442	0.0363	1.0476	0.051*
H8C	0.2601	0.1959	1.03	0.051*
C9	0.15900 (7)	0.20383 (18)	1.00423 (15)	0.0412 (4)
H9A	0.1789	0.2857	1.049	0.062*
H9B	0.1584	0.1299	1.0632	0.062*
H9C	0.123	0.233	0.9564	0.062*
C10	0.15454 (6)	0.02203 (16)	0.84575 (14)	0.0359 (3)
H10A	0.1191	0.0526	0.795	0.054*
H10B	0.1524	−0.0522	0.9029	0.054*
H10C	0.1725	−0.0153	0.7923	0.054*
C11	0.16978 (5)	0.51181 (13)	0.69474 (10)	0.0183 (2)
C12	0.08595 (4)	0.57415 (14)	0.71249 (11)	0.0208 (2)
C13	0.10986 (6)	0.63856 (16)	0.83951 (13)	0.0310 (3)
H13A	0.1201	0.5629	0.9014	0.046*
H13B	0.0841	0.7004	0.8556	0.046*
H13C	0.1408	0.6942	0.8439	0.046*
C14	0.03931 (5)	0.48195 (15)	0.70301 (14)	0.0295 (3)
H14A	0.0269	0.4342	0.6227	0.044*
H14B	0.0112	0.5411	0.7112	0.044*
H14C	0.0497	0.4109	0.769	0.044*
C15	0.07098 (5)	0.68538 (16)	0.61068 (13)	0.0294 (3)
H15A	0.1005	0.7501	0.6232	0.044*
H15B	0.0406	0.7391	0.6129	0.044*
H15C	0.0622	0.6385	0.5304	0.044*
C16	0.38183 (5)	0.27894 (15)	0.75821 (11)	0.0241 (3)
H16	0.3863	0.3166	0.842	0.029*
C17	0.39093 (5)	0.11852 (15)	0.77060 (11)	0.0243 (3)
H17	0.3935	0.0812	0.6922	0.029*
C18	0.44260 (5)	0.08832 (18)	0.87695 (12)	0.0339 (3)
H18A	0.4404	0.1243	0.9543	0.051*
H18B	0.4715	0.1355	0.8606	0.051*
H18C	0.4489	−0.0142	0.8838	0.051*
C19	0.34592 (5)	0.04375 (15)	0.79477 (12)	0.0273 (3)
H19A	0.3531	−0.0582	0.8044	0.041*
H19B	0.3132	0.06	0.7251	0.041*
H19C	0.3425	0.0815	0.8704	0.041*
C20	0.42136 (5)	0.35571 (15)	0.71361 (13)	0.0266 (3)
C21	0.44367 (6)	0.59566 (17)	0.66729 (18)	0.0416 (4)
C22	0.42311 (7)	0.73765 (19)	0.6920 (3)	0.0610 (6)
H22A	0.3851	0.7418	0.6487	0.091*
H22B	0.4399	0.8141	0.6623	0.091*
H22C	0.431	0.7487	0.7808	0.091*
C23	0.42947 (9)	0.5699 (2)	0.5302 (2)	0.0585 (5)
H23A	0.4446	0.4798	0.5173	0.088*
H23B	0.4433	0.6473	0.4942	0.088*
H23C	0.3913	0.5662	0.4905	0.088*
C24	0.50190 (6)	0.5826 (2)	0.7382 (2)	0.0567 (5)
H24A	0.5086	0.5904	0.8268	0.085*
H24B	0.5205	0.6586	0.713	0.085*
H24C	0.5143	0.4904	0.7207	0.085*
N1	0.32921 (4)	0.31854 (11)	0.67548 (9)	0.0202 (2)
N2	0.20095 (4)	0.39526 (11)	0.69179 (9)	0.0193 (2)
O1	0.30559 (3)	0.38315 (10)	0.83680 (8)	0.0241 (2)
O2	0.21970 (3)	0.15970 (9)	0.71609 (8)	0.02276 (19)
O3	0.18130 (4)	0.27044 (9)	0.83558 (8)	0.02354 (19)
O4	0.18374 (3)	0.63235 (9)	0.69062 (8)	0.02172 (18)
O5	0.12315 (3)	0.46991 (9)	0.69416 (8)	0.02019 (18)
O6	0.45332 (4)	0.29793 (11)	0.68025 (10)	0.0334 (2)
O7	0.41427 (4)	0.49542 (10)	0.71647 (10)	0.0339 (2)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0190 (5)	0.0172 (6)	0.0226 (6)	−0.0022 (5)	0.0079 (5)	−0.0031 (5)
C2	0.0191 (5)	0.0204 (6)	0.0220 (6)	0.0017 (5)	0.0114 (5)	0.0025 (5)
C3	0.0210 (6)	0.0251 (6)	0.0202 (6)	0.0024 (5)	0.0062 (5)	0.0028 (5)
C4	0.0256 (6)	0.0246 (6)	0.0189 (6)	0.0019 (5)	0.0099 (5)	0.0014 (5)
C5	0.0238 (6)	0.0250 (6)	0.0201 (6)	0.0014 (5)	0.0112 (5)	−0.0030 (5)
C6	0.0170 (5)	0.0195 (6)	0.0201 (6)	0.0002 (4)	0.0059 (4)	0.0016 (5)
C7	0.0273 (6)	0.0211 (6)	0.0252 (6)	0.0021 (5)	0.0130 (5)	0.0082 (5)
C8	0.0304 (7)	0.0421 (8)	0.0278 (7)	0.0013 (6)	0.0072 (6)	0.0126 (6)
C9	0.0626 (10)	0.0347 (8)	0.0419 (8)	0.0146 (7)	0.0380 (8)	0.0147 (7)
C10	0.0350 (7)	0.0340 (8)	0.0393 (8)	−0.0104 (6)	0.0140 (6)	0.0054 (6)
C11	0.0189 (5)	0.0210 (6)	0.0154 (5)	0.0016 (5)	0.0066 (4)	0.0016 (4)
C12	0.0190 (6)	0.0217 (6)	0.0242 (6)	0.0050 (5)	0.0107 (5)	0.0023 (5)
C13	0.0322 (7)	0.0346 (7)	0.0312 (7)	0.0003 (6)	0.0175 (6)	−0.0046 (6)
C14	0.0232 (6)	0.0280 (7)	0.0417 (8)	0.0010 (6)	0.0171 (5)	0.0017 (6)
C15	0.0244 (6)	0.0317 (7)	0.0348 (7)	0.0088 (6)	0.0139 (5)	0.0106 (6)
C16	0.0176 (6)	0.0314 (7)	0.0226 (6)	0.0003 (5)	0.0064 (5)	−0.0077 (5)
C17	0.0219 (6)	0.0315 (7)	0.0194 (6)	0.0051 (5)	0.0071 (5)	−0.0030 (5)
C18	0.0242 (6)	0.0494 (9)	0.0255 (7)	0.0091 (6)	0.0055 (5)	−0.0005 (6)
C19	0.0268 (6)	0.0316 (7)	0.0237 (6)	0.0050 (5)	0.0093 (5)	0.0027 (5)
C20	0.0177 (6)	0.0295 (7)	0.0300 (6)	−0.0012 (5)	0.0055 (5)	−0.0103 (5)
C21	0.0267 (7)	0.0263 (8)	0.0749 (11)	−0.0062 (6)	0.0220 (7)	−0.0076 (7)
C22	0.0371 (9)	0.0299 (9)	0.1201 (19)	−0.0021 (7)	0.0331 (11)	−0.0089 (10)
C23	0.0633 (11)	0.0450 (10)	0.0737 (13)	−0.0162 (9)	0.0321 (10)	0.0036 (10)
C24	0.0276 (8)	0.0362 (9)	0.1048 (16)	−0.0080 (7)	0.0215 (9)	−0.0115 (10)
N1	0.0176 (5)	0.0245 (5)	0.0188 (5)	0.0002 (4)	0.0067 (4)	−0.0046 (4)
N2	0.0185 (5)	0.0181 (5)	0.0239 (5)	0.0023 (4)	0.0109 (4)	0.0029 (4)
O1	0.0227 (4)	0.0302 (5)	0.0204 (4)	0.0020 (4)	0.0088 (3)	−0.0057 (4)
O2	0.0266 (4)	0.0188 (4)	0.0252 (4)	0.0030 (3)	0.0122 (3)	0.0011 (3)
O3	0.0299 (4)	0.0195 (4)	0.0266 (4)	0.0046 (4)	0.0167 (4)	0.0051 (4)
O4	0.0231 (4)	0.0181 (4)	0.0272 (4)	0.0004 (3)	0.0129 (3)	0.0020 (3)
O5	0.0181 (4)	0.0183 (4)	0.0266 (4)	0.0021 (3)	0.0110 (3)	0.0010 (3)
O6	0.0260 (5)	0.0315 (5)	0.0491 (6)	−0.0011 (4)	0.0210 (4)	−0.0096 (4)
O7	0.0236 (5)	0.0268 (5)	0.0550 (6)	−0.0036 (4)	0.0184 (4)	−0.0112 (5)

Geometric parameters (Å, º) top

C1—O1	1.2202 (15)	C13—H13A	0.98
C1—N1	1.3545 (16)	C13—H13B	0.98
C1—C2	1.5382 (15)	C13—H13C	0.98
C2—N2	1.4679 (15)	C14—H14A	0.98
C2—C3	1.5215 (17)	C14—H14B	0.98
C2—H2	1	C14—H14C	0.98
C3—C4	1.5220 (16)	C15—H15A	0.98
C3—H3A	0.99	C15—H15B	0.98
C3—H3B	0.99	C15—H15C	0.98
C4—C5	1.5165 (17)	C16—N1	1.4646 (15)
C4—H4A	0.99	C16—C17	1.5317 (19)
C4—H4B	0.99	C16—C20	1.5327 (19)
C5—N1	1.4688 (15)	C16—H16	1
C5—H5A	0.99	C17—C19	1.5254 (18)
C5—H5B	0.99	C17—C18	1.5353 (17)
C6—O2	1.2035 (15)	C17—H17	1
C6—O3	1.3217 (15)	C18—H18A	0.98
C6—N2	1.4074 (16)	C18—H18B	0.98
C7—O3	1.4902 (14)	C18—H18C	0.98
C7—C10	1.507 (2)	C19—H19A	0.98
C7—C9	1.5107 (19)	C19—H19B	0.98
C7—C8	1.5145 (18)	C19—H19C	0.98
C8—H8A	0.98	C20—O6	1.2021 (17)
C8—H8B	0.98	C20—O7	1.3339 (18)
C8—H8C	0.98	C21—O7	1.4785 (19)
C9—H9A	0.98	C21—C24	1.513 (2)
C9—H9B	0.98	C21—C23	1.515 (3)
C9—H9C	0.98	C21—C22	1.518 (2)
C10—H10A	0.98	C22—H22A	0.98
C10—H10B	0.98	C22—H22B	0.98
C10—H10C	0.98	C22—H22C	0.98
C11—O4	1.2052 (15)	C23—H23A	0.98
C11—O5	1.3298 (15)	C23—H23B	0.98
C11—N2	1.3976 (16)	C23—H23C	0.98
C12—O5	1.4813 (14)	C24—H24A	0.98
C12—C13	1.5105 (18)	C24—H24B	0.98
C12—C14	1.5127 (17)	C24—H24C	0.98
C12—C15	1.5224 (17)

O1—C1—N1	123.21 (11)	H14A—C14—H14B	109.5
O1—C1—C2	119.83 (11)	C12—C14—H14C	109.5
N1—C1—C2	116.74 (10)	H14A—C14—H14C	109.5
N2—C2—C3	112.35 (10)	H14B—C14—H14C	109.5
N2—C2—C1	109.72 (9)	C12—C15—H15A	109.5
C3—C2—C1	115.44 (10)	C12—C15—H15B	109.5
N2—C2—H2	106.2	H15A—C15—H15B	109.5
C3—C2—H2	106.2	C12—C15—H15C	109.5
C1—C2—H2	106.2	H15A—C15—H15C	109.5
C2—C3—C4	108.87 (10)	H15B—C15—H15C	109.5
C2—C3—H3A	109.9	N1—C16—C17	113.71 (10)
C4—C3—H3A	109.9	N1—C16—C20	107.61 (11)
C2—C3—H3B	109.9	C17—C16—C20	112.84 (10)
C4—C3—H3B	109.9	N1—C16—H16	107.5
H3A—C3—H3B	108.3	C17—C16—H16	107.5
C5—C4—C3	108.66 (10)	C20—C16—H16	107.5
C5—C4—H4A	110	C19—C17—C16	111.07 (10)
C3—C4—H4A	110	C19—C17—C18	109.69 (11)
C5—C4—H4B	110	C16—C17—C18	109.32 (11)
C3—C4—H4B	110	C19—C17—H17	108.9
H4A—C4—H4B	108.3	C16—C17—H17	108.9
N1—C5—C4	112.37 (10)	C18—C17—H17	108.9
N1—C5—H5A	109.1	C17—C18—H18A	109.5
C4—C5—H5A	109.1	C17—C18—H18B	109.5
N1—C5—H5B	109.1	H18A—C18—H18B	109.5
C4—C5—H5B	109.1	C17—C18—H18C	109.5
H5A—C5—H5B	107.9	H18A—C18—H18C	109.5
O2—C6—O3	127.53 (11)	H18B—C18—H18C	109.5
O2—C6—N2	121.03 (11)	C17—C19—H19A	109.5
O3—C6—N2	111.35 (10)	C17—C19—H19B	109.5
O3—C7—C10	110.94 (10)	H19A—C19—H19B	109.5
O3—C7—C9	101.83 (10)	C17—C19—H19C	109.5
C10—C7—C9	110.80 (12)	H19A—C19—H19C	109.5
O3—C7—C8	109.41 (10)	H19B—C19—H19C	109.5
C10—C7—C8	112.32 (12)	O6—C20—O7	125.73 (14)
C9—C7—C8	111.06 (12)	O6—C20—C16	124.84 (13)
C7—C8—H8A	109.5	O7—C20—C16	109.43 (11)
C7—C8—H8B	109.5	O7—C21—C24	110.31 (15)
H8A—C8—H8B	109.5	O7—C21—C23	109.23 (13)
C7—C8—H8C	109.5	C24—C21—C23	112.71 (16)
H8A—C8—H8C	109.5	O7—C21—C22	101.79 (13)
H8B—C8—H8C	109.5	C24—C21—C22	110.88 (14)
C7—C9—H9A	109.5	C23—C21—C22	111.37 (18)
C7—C9—H9B	109.5	C21—C22—H22A	109.5
H9A—C9—H9B	109.5	C21—C22—H22B	109.5
C7—C9—H9C	109.5	H22A—C22—H22B	109.5
H9A—C9—H9C	109.5	C21—C22—H22C	109.5
H9B—C9—H9C	109.5	H22A—C22—H22C	109.5
C7—C10—H10A	109.5	H22B—C22—H22C	109.5
C7—C10—H10B	109.5	C21—C23—H23A	109.5
H10A—C10—H10B	109.5	C21—C23—H23B	109.5
C7—C10—H10C	109.5	H23A—C23—H23B	109.5
H10A—C10—H10C	109.5	C21—C23—H23C	109.5
H10B—C10—H10C	109.5	H23A—C23—H23C	109.5
O4—C11—O5	126.53 (11)	H23B—C23—H23C	109.5
O4—C11—N2	122.50 (11)	C21—C24—H24A	109.5
O5—C11—N2	110.82 (10)	C21—C24—H24B	109.5
O5—C12—C13	108.98 (10)	H24A—C24—H24B	109.5
O5—C12—C14	102.08 (10)	C21—C24—H24C	109.5
C13—C12—C14	111.34 (11)	H24A—C24—H24C	109.5
O5—C12—C15	110.83 (10)	H24B—C24—H24C	109.5
C13—C12—C15	112.52 (12)	C1—N1—C16	118.35 (10)
C14—C12—C15	110.60 (11)	C1—N1—C5	124.89 (10)
C12—C13—H13A	109.5	C16—N1—C5	116.10 (10)
C12—C13—H13B	109.5	C11—N2—C6	126.44 (10)
H13A—C13—H13B	109.5	C11—N2—C2	117.23 (10)
C12—C13—H13C	109.5	C6—N2—C2	116.08 (10)
H13A—C13—H13C	109.5	C6—O3—C7	120.10 (10)
H13B—C13—H13C	109.5	C11—O5—C12	120.31 (9)
C12—C14—H14A	109.5	C20—O7—C21	121.25 (11)
C12—C14—H14B	109.5

O1—C1—C2—N2	−34.52 (15)	O5—C11—N2—C6	−33.73 (15)
N1—C1—C2—N2	150.65 (10)	O4—C11—N2—C2	−23.56 (16)
O1—C1—C2—C3	−162.67 (11)	O5—C11—N2—C2	152.30 (10)
N1—C1—C2—C3	22.50 (16)	O2—C6—N2—C11	162.50 (11)
N2—C2—C3—C4	−174.17 (10)	O3—C6—N2—C11	−20.70 (16)
C1—C2—C3—C4	−47.33 (14)	O2—C6—N2—C2	−23.47 (16)
C2—C3—C4—C5	62.18 (13)	O3—C6—N2—C2	153.33 (10)
C3—C4—C5—N1	−52.90 (14)	C3—C2—N2—C11	−102.88 (12)
N1—C16—C17—C19	−47.91 (14)	C1—C2—N2—C11	127.27 (11)
C20—C16—C17—C19	−170.83 (10)	C3—C2—N2—C6	82.52 (13)
N1—C16—C17—C18	−169.09 (10)	C1—C2—N2—C6	−47.33 (14)
C20—C16—C17—C18	67.99 (14)	O2—C6—O3—C7	5.36 (18)
N1—C16—C20—O6	−119.62 (14)	N2—C6—O3—C7	−171.17 (9)
C17—C16—C20—O6	6.64 (18)	C10—C7—O3—C6	−63.25 (15)
N1—C16—C20—O7	59.70 (13)	C9—C7—O3—C6	178.81 (12)
C17—C16—C20—O7	−174.04 (10)	C8—C7—O3—C6	61.23 (15)
O1—C1—N1—C16	1.70 (18)	O4—C11—O5—C12	−11.94 (17)
C2—C1—N1—C16	176.34 (11)	N2—C11—O5—C12	172.41 (9)
O1—C1—N1—C5	172.01 (12)	C13—C12—O5—C11	−62.98 (14)
C2—C1—N1—C5	−13.36 (18)	C14—C12—O5—C11	179.17 (10)
C17—C16—N1—C1	105.82 (13)	C15—C12—O5—C11	61.37 (13)
C20—C16—N1—C1	−128.44 (12)	O6—C20—O7—C21	5.1 (2)
C17—C16—N1—C5	−65.34 (14)	C16—C20—O7—C21	−174.19 (12)
C20—C16—N1—C5	60.40 (14)	C24—C21—O7—C20	−61.66 (19)
C4—C5—N1—C1	29.46 (17)	C23—C21—O7—C20	62.76 (18)
C4—C5—N1—C16	−160.04 (11)	C22—C21—O7—C20	−179.40 (14)
O4—C11—N2—C6	150.41 (12)

Experimental details

Crystal data
Chemical formula	C₂₄H₄₂N₂O₇
M_r	470.6
Crystal system, space group	Monoclinic, C2
Temperature (K)	86
a, b, c (Å)	27.282 (3), 9.4315 (10), 11.5884 (10)
β (°)	110.729 (1)
V (Å³)	2788.7 (5)
Z	4
Radiation type	Cu Kα
µ (mm⁻¹)	0.67
Crystal size (mm)	0.35 × 0.25 × 0.20

Data collection
Diffractometer	Bruker Kappa APEXII CCD diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 2004)
T_min, T_max	0.800, 0.878
No. of measured, independent and observed [I > 2σ(I)] reflections	10823, 4844, 4782
R_int	0.023
(sin θ/λ)_max (Å⁻¹)	0.602

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.026, 0.071, 1.01
No. of reflections	4844
No. of parameters	310
No. of restraints	1
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.19, −0.12
Absolute structure	Flack (1983), 2174 Friedel pairs
Absolute structure parameter	−0.02 (10)

Computer programs: APEX2 (Bruker, 2006), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).

Footnotes

†CAS Registry Number 500222-63-9.

Acknowledgements

We are grateful to Dr Umut Oguz for providing the crystalline sample.

References

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