(4S,5S)-4-[(1R)-1,2-Di­hydroxy­ethyl]-5-tri­decyl-1,3-oxazolidin-2-one

The title compound, C₁₈H₃₅NO₄, is a new bioactive amphiphilic lipid with a cis-substituted 1,3-oxazolidin-2-one head group. In the crystal structure, the mol­ecules form intercalating bilayers in which the oxazolidinone head groups are joined together by hydrogen bonds into chains.

S1. Comment

In the course of the synthesis of conformationally restricted sphingolipid analogues (Brodesser et al., 2003; Kolter, 2003), the precursor (II) of the title compound, (I), was prepared from Garner's aldehyde (Garner et al., 1988) according to Sawatzki (2003). Compound (I) was demonstrated to be an inhibitor of sphinganine hydroxylation and a potent mitogen in S. cerevisiae (Sawatzki, 2003). Removal of the benzoate and isopropylidene protective groups in (II) afforded (I).

The structure of (I) with the atom-numbering is shown in Fig. 1. Selected geometrical parameters are listed in Table 1. The 1,3-oxazolidin-2-one ring adopts an open envelope conformation, with atom C2 out of the plane. The intra-ring bond lengths C5—N1 and C4—O3, which are opposite each other, are similar; also the lengths of the adjacent bonds N1—C2 and O3—C2 within the ring show comparable similarity, with a maximum deviation of 0.03 Å. The intra-ring bond angles, however, are different and range from 98.57 (13) to 113.34 (12)°. The pseudo-axially arranged dihydroxyethyl and alkyl substituents at the 4- and 5- positions of the oxazolidinone ring are in a cisoid configuration. Both substituents show a distorted synperiplanar conformation, with a C8—C4—C5—C6 torsion angle of 21.9 (2)°, whereas within the dihydroxyethyl moiety, the OH groups are in a fully staggered relationship, with a O6—C6—C7—O7 torsion angle of −179.55 (13)°. The conformation of the tridecyl chain is as most often found for larger alkanes, i.e. staggered with the largest substituents at any C—C bond antiperiplanar to each other. The average C—C bond length within the chain is 1.527 (2) Å [range 1.524 (2)–1.530 (2) Å] and the average angle is 113 (2)° [range 112.6 (1)–113.9 (2)°]. These values are similar to those found in related amphiphilic lipids (Ramos Silva et al., 2000; Matos Beja et al., 2001). The zigzag tridecyl backbone shows a significant deviation from planarity, being bent towards atom C9; the deviation from the ideal torsion angle of 180° for C8—C9—C10—C11 is 4.10 (14)°. Also, the bond lengths C8—C9 and C9—C10 appear to diverge slightly from the average bond length found in the alkyl chain. A weaker second bend can be found at C16—C17—C18—C19 of the hydrocarbon chain [deviation 2.41 (14)°].

Three intermolecular hydrogen bonds of normal strength (Steiner, 2002) are present (Table 2), forming a nearly linear arrangement in the crystal. The greatest deviation from the ideal angle of 180° is 19.0 (2)° for the strongest hydrogen bond O7—H7O···O2. In the crystal structure, the molecule forms an intercalating bilayer generated by the 2₁ axis, with a lipophilic core and a hydrophilic surface (Fig. 2). The molecular packing is such that the hydrocarbon chains lie side by side, thereby forming alternating layers of carbon tails and oxazolidin-2-one heads. The hydrophilic heads are connected by a network of hydrogen bonds involving the two hydroxyl groups, the carbonyl group and an amide group, viz. O6—H6O···O7ⁱⁱ, O7—H7O···O2ⁱⁱⁱ and N1—H1N···O7ⁱ (see Table 2 for symmetry codes and geometric details). The O7—H7O hydroxy group is involved in three hydrogen bonds. It acts as a hydrogen-bond acceptor and donor in the network connecting the hydrophilic heads of the bilayer. The 2₁ axis further relates each bilayer to its neighbours. Each bilayer is connected to the next via a hydrogen bond between the N1 amino group as donor and the O7 hydroxy group as acceptor. These hydrogen bonds join the oxazolidinone moieties of the molecules head-to-head within and also between the layers (Fig. 3).

S2. Experimental

The starting material (1S,8R,8aS)-5,5-dimethyl-1-tridecyl-3- oxotetrahydro[1,3]oxazolo[3,4-c][1,3]oxazin-8-yl benzoate, (II), was prepared from Garners aldehyde (Garner et al., 1988; Campbell et al., 1998). In brief, Garner's aldehyde is elongated by a Wittig reaction with a long-chain phosphorous ylide followed by an intramolecular iodolactonization (Ageno et al., 1995) of the Z-olefin. Molecular rearrangement induced by silver acetate in acetic acid followed by exchange of benzoyl for acetyl protection with inversion of configuration at C8 afforded (II) (Sawatzki, 2003). Glassware was flame dried under an argon atmosphere and allowed to cool. Compound (II) (207.1 mg, 437.3 µmol) was dissolved in methanol and a catalytic amount of sodium hydroxide in methanol (1 M) added. Stirring was continued for 18 h and the solvent evaporated under reduced pressure. The residue was dissolved in THF/0.5 M HCl (1:1) and stirred at 353 K for 18 h under reflux. After cooling to ambient temperature, the solution was neutralized with saturated sodium hydrogencarbonate solution and concentrated under reduced pressure. The residue was extracted with chloroform and the organic phase dried over sodium sulfate. After evaporation of the solvent, the residue obtained was purified by column chromatography on silica gel with chloroform/methanol (10:1) as eluant (yield: 122.9 mg, 85.3%). The purification afforded a few colourless crystals suitable for X-ray analysis. TLC: 10:1 chloroform-methanol, R_F = 0.41; m.p.: 365 K (sharp); α_D = −16.1° (c = 0.26 in MeOH/CHCl₃ 1:1); ¹H NMR (500 MHz, CD₃OD/CDCl₃ 1:1): δ 0.86 (t, J = 7 Hz, 3H; CH₃), 1.25 (m, 16H; CH₂), 1.36 (m, 4H; CH₂), 1.56 (m, 2H; CH₂), 1.69 (m, 1H; CH₂), 1.97 (m, 1H; CH₂), 3.50 (td, J = 5.7 Hz, J = 11.5 Hz, 1H; CH₂OH), 3.54 (td, J = 5.7 Hz, J = 11.5 Hz, 1H; CH₂OH), 3.72 (dt, J = 2.2 Hz, J = 5.7 Hz, 1H; H-5), 3.81 (dd, J = 2.2 Hz, J = 7.8 Hz, 1H; H-4), 4.63 (ddd, J = 3.8 Hz, J = 7.8 Hz, J = 10.1 Hz, 1H; H-1'); ¹³C NMR (100 MHz, CD₃OD/CDCl₃ 1:1): δ 14.9 (CH₃), 23.9–33.2 (CH₂), 58.1 (C-5), 65.1 (CH₂OH), 70.1 (C-4), 81.9 (C-1'), 162.8 (C-2); FAB-MS (3-nitrobenzoic acid): m/z = 330 (M + H)⁺; IR: 1697.7 cm⁻¹.

S3. Refinement

Friedel pairs were merged prior to the final refinement. The absolute configuration of (I) was assigned to agree with the chirality established by the synthesis. The positions of the amide H atom and the hydroxy H atoms were determined from a difference Fourier map and the coordinates were refined freely, with isotropic displacement parameters constrained to U_iso(H) = 1.2U_eq (N) and 1.5U_eq (O). All remaining H atoms were treated as riding, with C—H = 0.98–1.00 Å and U_iso(H) = 1.2U_eq (CH, CH₂) and 1.5U_eq (CH₃).

Computing details

Data collection: COLLECT (Nonius, 1997-2000); cell refinement: DENZO–SMN (Otwinowski & Minor, 1997); data reduction: DENZO–SMN; program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL-NT (Sheldrick, 2001); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. The structure of (I), showing the atom-numbering scheme and displacement ellipsoids at the 50% probability level for non-H atoms.
	Fig. 2. The packing of the hydrocarbon chains in the crystal structure, with alternating layers of carbon tails and oxazolidin-2-one head groups.
	Fig. 3. View of the unit-cell packing, showing the network of hydrogen bonds as dashed lines.

(4S,5S)-4-[(1R)-1,2-Dihydroxyethyl]-5-tridecyl-1,3-oxazolidin-2-one

Crystal data

C18H35NO4	F(000) = 364
Mr = 329.47	Dx = 1.203 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
a = 5.4040 (2) Å	Cell parameters from 9695 reflections
b = 7.6062 (4) Å	θ = 2–28.3°
c = 22.1898 (11) Å	µ = 0.08 mm^−1
β = 94.208 (3)°	T = 123 K
V = 909.63 (7) Å^3	Plates, colourless
Z = 2	0.50 × 0.40 × 0.02 mm

Data collection

Nonius KappaCCD diffractometer	2037 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.043
Graphite monochromator	θmax = 28.3°, θmin = 3.3°
rotation in ϕ and ω (1°) scans	h = −7→7
10314 measured reflections	k = −10→10
2337 independent reflections	l = −28→29

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.034	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.084	w = 1/[σ^2(Fo^2) + (0.0547P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.01	(Δ/σ)max < 0.001
2337 reflections	Δρmax = 0.22 e Å^−3
217 parameters	Δρmin = −0.21 e Å^−3
1 restraint	Absolute structure: Flack (1983), 2076 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.6 (10)

Special details

Experimental. dx = 40 mm, 150 sec./°., 1 °., 4 sets., 486 frames, mos.= 0.855 (2) °.

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. The data are merged (use of MERG 3). Not merging the friedel pairs (2076) achive a flack parameter (x = 0.0 (8)), which corresponds to the known absoltue configuration.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
N1	1.3064 (3)	0.6374 (2)	0.91674 (6)	0.0195 (3)
H1N	1.401 (4)	0.628 (3)	0.9488 (9)	0.023*
C2	1.1842 (3)	0.4973 (2)	0.89448 (7)	0.0190 (3)
O2	1.1740 (2)	0.35029 (18)	0.91611 (5)	0.0260 (3)
O3	1.0645 (2)	0.53724 (17)	0.84029 (5)	0.0211 (3)
C4	1.1393 (3)	0.7131 (2)	0.82316 (7)	0.0169 (3)
H4	1.2781	0.7009	0.7960	0.020*
C5	1.2460 (3)	0.7976 (2)	0.88307 (6)	0.0161 (3)
H5	1.4038	0.8599	0.8755	0.019*
C6	1.0807 (3)	0.9224 (2)	0.91563 (7)	0.0176 (3)
H6	1.0399	1.0262	0.8891	0.021*
O6	0.8561 (2)	0.83364 (18)	0.92720 (5)	0.0226 (3)
H6O	0.761 (4)	0.914 (3)	0.9416 (9)	0.034*
C7	1.2094 (3)	0.9861 (2)	0.97516 (7)	0.0187 (3)
H7A	1.0965	1.0655	0.9955	0.022*
H7B	1.2464	0.8841	1.0020	0.022*
O7	1.4355 (2)	1.07753 (18)	0.96579 (5)	0.0210 (3)
H7O	1.388 (4)	1.168 (4)	0.9540 (10)	0.032*
C8	0.9229 (3)	0.8002 (2)	0.78716 (7)	0.0193 (3)
H8A	0.9629	0.9253	0.7803	0.023*
H8B	0.7742	0.7957	0.8106	0.023*
C9	0.8664 (3)	0.7090 (3)	0.72625 (7)	0.0214 (4)
H9A	0.8236	0.5846	0.7336	0.026*
H9B	1.0179	0.7103	0.7037	0.026*
C10	0.6542 (3)	0.7940 (3)	0.68708 (7)	0.0212 (4)
H10A	0.4996	0.7848	0.7082	0.025*
H10B	0.6911	0.9204	0.6821	0.025*
C11	0.6125 (3)	0.7097 (3)	0.62486 (7)	0.0226 (4)
H11A	0.5771	0.5831	0.6299	0.027*
H11B	0.7669	0.7197	0.6037	0.027*
C12	0.3997 (3)	0.7928 (3)	0.58562 (7)	0.0230 (4)
H12A	0.4327	0.9201	0.5815	0.028*
H12B	0.2443	0.7800	0.6062	0.028*
C13	0.3628 (3)	0.7114 (3)	0.52266 (7)	0.0244 (4)
H13A	0.5175	0.7255	0.5019	0.029*
H13B	0.3318	0.5838	0.5268	0.029*
C14	0.1484 (3)	0.7928 (3)	0.48369 (7)	0.0241 (4)
H14A	0.1790	0.9204	0.4796	0.029*
H14B	−0.0065	0.7783	0.5044	0.029*
C15	0.1129 (3)	0.7114 (3)	0.42079 (7)	0.0243 (4)
H15A	0.2672	0.7275	0.4000	0.029*
H15B	0.0851	0.5835	0.4250	0.029*
C16	−0.1033 (3)	0.7898 (3)	0.38166 (7)	0.0236 (4)
H16A	−0.0742	0.9173	0.3767	0.028*
H16B	−0.2574	0.7756	0.4027	0.028*
C17	−0.1399 (3)	0.7051 (3)	0.31923 (7)	0.0230 (4)
H17A	0.0136	0.7207	0.2981	0.028*
H17B	−0.1662	0.5773	0.3243	0.028*
C18	−0.3579 (3)	0.7803 (3)	0.27979 (7)	0.0219 (4)
H18A	−0.3284	0.9071	0.2731	0.026*
H18B	−0.5107	0.7692	0.3015	0.026*
C19	−0.3981 (3)	0.6887 (2)	0.21858 (7)	0.0211 (4)
H19A	−0.2469	0.7022	0.1964	0.025*
H19B	−0.4242	0.5616	0.2252	0.025*
C20	−0.6198 (3)	0.7623 (3)	0.18013 (7)	0.0250 (4)
H20A	−0.6376	0.6996	0.1415	0.038*
H20B	−0.5935	0.8877	0.1727	0.038*
H20C	−0.7708	0.7469	0.2015	0.038*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0246 (7)	0.0148 (7)	0.0180 (6)	0.0020 (6)	−0.0059 (6)	0.0017 (6)
C2	0.0203 (7)	0.0176 (8)	0.0190 (7)	0.0038 (6)	0.0013 (6)	−0.0001 (6)
O2	0.0326 (6)	0.0159 (6)	0.0289 (6)	0.0002 (5)	−0.0010 (5)	0.0037 (5)
O3	0.0255 (6)	0.0150 (6)	0.0218 (6)	−0.0032 (5)	−0.0049 (4)	0.0002 (5)
C4	0.0175 (7)	0.0169 (8)	0.0160 (7)	−0.0031 (6)	−0.0019 (6)	0.0008 (6)
C5	0.0168 (7)	0.0142 (8)	0.0165 (7)	−0.0020 (6)	−0.0034 (5)	0.0021 (6)
C6	0.0172 (7)	0.0165 (8)	0.0185 (7)	−0.0028 (6)	−0.0031 (6)	0.0020 (6)
O6	0.0193 (5)	0.0205 (7)	0.0281 (6)	−0.0043 (5)	0.0030 (5)	−0.0046 (5)
C7	0.0214 (7)	0.0154 (8)	0.0187 (7)	−0.0015 (6)	−0.0020 (6)	−0.0003 (6)
O7	0.0218 (6)	0.0161 (6)	0.0240 (6)	−0.0028 (5)	−0.0057 (4)	0.0015 (5)
C8	0.0209 (7)	0.0187 (9)	0.0173 (7)	−0.0013 (7)	−0.0041 (6)	−0.0004 (7)
C9	0.0212 (7)	0.0243 (9)	0.0180 (7)	−0.0001 (7)	−0.0042 (6)	−0.0010 (7)
C10	0.0203 (7)	0.0247 (10)	0.0179 (7)	−0.0007 (7)	−0.0040 (6)	−0.0008 (7)
C11	0.0225 (8)	0.0289 (10)	0.0156 (7)	−0.0005 (7)	−0.0039 (6)	0.0006 (7)
C12	0.0219 (7)	0.0284 (10)	0.0176 (7)	−0.0003 (7)	−0.0047 (6)	−0.0007 (7)
C13	0.0233 (8)	0.0308 (10)	0.0184 (7)	−0.0004 (8)	−0.0044 (6)	0.0001 (7)
C14	0.0221 (8)	0.0313 (10)	0.0182 (7)	0.0001 (7)	−0.0037 (6)	−0.0008 (7)
C15	0.0216 (8)	0.0314 (11)	0.0190 (7)	0.0009 (8)	−0.0044 (6)	0.0011 (7)
C16	0.0212 (7)	0.0293 (10)	0.0196 (7)	0.0008 (7)	−0.0031 (6)	0.0005 (7)
C17	0.0205 (8)	0.0291 (10)	0.0187 (7)	0.0018 (7)	−0.0030 (6)	0.0010 (7)
C18	0.0201 (7)	0.0239 (10)	0.0209 (7)	0.0024 (7)	−0.0025 (6)	−0.0007 (7)
C19	0.0200 (7)	0.0241 (10)	0.0187 (7)	0.0005 (7)	−0.0014 (6)	0.0008 (7)
C20	0.0206 (8)	0.0328 (11)	0.0212 (7)	0.0022 (7)	−0.0023 (6)	0.0001 (8)

Geometric parameters (Å, º)

N1—C2	1.330 (2)	C11—H11A	0.9900
N1—C5	1.454 (2)	C11—H11B	0.9900
N1—H1N	0.85 (2)	C12—C13	1.528 (2)
C2—O2	1.219 (2)	C12—H12A	0.9900
C2—O3	1.3575 (19)	C12—H12B	0.9900
O3—C4	1.456 (2)	C13—C14	1.526 (2)
C4—C8	1.519 (2)	C13—H13A	0.9900
C4—C5	1.549 (2)	C13—H13B	0.9900
C4—H4	1.0000	C14—C15	1.526 (2)
C5—C6	1.522 (2)	C14—H14A	0.9900
C5—H5	1.0000	C14—H14B	0.9900
C6—O6	1.4283 (19)	C15—C16	1.525 (2)
C6—C7	1.526 (2)	C15—H15A	0.9900
C6—H6	1.0000	C15—H15B	0.9900
O6—H6O	0.88 (2)	C16—C17	1.528 (2)
C7—O7	1.434 (2)	C16—H16A	0.9900
C7—H7A	0.9900	C16—H16B	0.9900
C7—H7B	0.9900	C17—C18	1.526 (2)
O7—H7O	0.77 (3)	C17—H17A	0.9900
C8—C9	1.530 (2)	C17—H17B	0.9900
C8—H8A	0.9900	C18—C19	1.528 (2)
C8—H8B	0.9900	C18—H18A	0.9900
C9—C10	1.530 (2)	C18—H18B	0.9900
C9—H9A	0.9900	C19—C20	1.525 (2)
C9—H9B	0.9900	C19—H19A	0.9900
C10—C11	1.524 (2)	C19—H19B	0.9900
C10—H10A	0.9900	C20—H20A	0.9800
C10—H10B	0.9900	C20—H20B	0.9800
C11—C12	1.527 (2)	C20—H20C	0.9800
C2—N1—C5	113.21 (13)	H11A—C11—H11B	107.7
C2—N1—H1N	119.8 (16)	C11—C12—C13	113.29 (15)
C5—N1—H1N	126.9 (16)	C11—C12—H12A	108.9
O2—C2—N1	128.62 (15)	C13—C12—H12A	108.9
O2—C2—O3	121.44 (15)	C11—C12—H12B	108.9
N1—C2—O3	109.94 (14)	C13—C12—H12B	108.9
C2—O3—C4	108.28 (12)	H12A—C12—H12B	107.7
O3—C4—C8	108.67 (13)	C14—C13—C12	113.33 (15)
O3—C4—C5	104.48 (11)	C14—C13—H13A	108.9
C8—C4—C5	119.62 (14)	C12—C13—H13A	108.9
O3—C4—H4	107.9	C14—C13—H13B	108.9
C8—C4—H4	107.9	C12—C13—H13B	108.9
C5—C4—H4	107.9	H13A—C13—H13B	107.7
N1—C5—C6	113.34 (12)	C13—C14—C15	113.13 (15)
N1—C5—C4	98.57 (13)	C13—C14—H14A	109.0
C6—C5—C4	118.13 (12)	C15—C14—H14A	109.0
N1—C5—H5	108.7	C13—C14—H14B	109.0
C6—C5—H5	108.7	C15—C14—H14B	109.0
C4—C5—H5	108.7	H14A—C14—H14B	107.8
O6—C6—C5	109.07 (13)	C16—C15—C14	113.67 (15)
O6—C6—C7	109.51 (12)	C16—C15—H15A	108.8
C5—C6—C7	111.29 (12)	C14—C15—H15A	108.8
O6—C6—H6	109.0	C16—C15—H15B	108.8
C5—C6—H6	109.0	C14—C15—H15B	108.8
C7—C6—H6	109.0	H15A—C15—H15B	107.7
C6—O6—H6O	105.3 (16)	C15—C16—C17	113.22 (15)
O7—C7—C6	111.56 (12)	C15—C16—H16A	108.9
O7—C7—H7A	109.3	C17—C16—H16A	108.9
C6—C7—H7A	109.3	C15—C16—H16B	108.9
O7—C7—H7B	109.3	C17—C16—H16B	108.9
C6—C7—H7B	109.3	H16A—C16—H16B	107.7
H7A—C7—H7B	108.0	C18—C17—C16	113.89 (15)
C7—O7—H7O	102.4 (16)	C18—C17—H17A	108.8
C4—C8—C9	111.28 (14)	C16—C17—H17A	108.8
C4—C8—H8A	109.4	C18—C17—H17B	108.8
C9—C8—H8A	109.4	C16—C17—H17B	108.8
C4—C8—H8B	109.4	H17A—C17—H17B	107.7
C9—C8—H8B	109.4	C17—C18—C19	113.09 (14)
H8A—C8—H8B	108.0	C17—C18—H18A	109.0
C8—C9—C10	113.76 (15)	C19—C18—H18A	109.0
C8—C9—H9A	108.8	C17—C18—H18B	109.0
C10—C9—H9A	108.8	C19—C18—H18B	109.0
C8—C9—H9B	108.8	H18A—C18—H18B	107.8
C10—C9—H9B	108.8	C20—C19—C18	112.62 (14)
H9A—C9—H9B	107.7	C20—C19—H19A	109.1
C11—C10—C9	113.08 (14)	C18—C19—H19A	109.1
C11—C10—H10A	109.0	C20—C19—H19B	109.1
C9—C10—H10A	109.0	C18—C19—H19B	109.1
C11—C10—H10B	109.0	H19A—C19—H19B	107.8
C9—C10—H10B	109.0	C19—C20—H20A	109.5
H10A—C10—H10B	107.8	C19—C20—H20B	109.5
C10—C11—C12	113.43 (15)	H20A—C20—H20B	109.5
C10—C11—H11A	108.9	C19—C20—H20C	109.5
C12—C11—H11A	108.9	H20A—C20—H20C	109.5
C10—C11—H11B	108.9	H20B—C20—H20C	109.5
C12—C11—H11B	108.9
C5—N1—C2—O2	−171.24 (16)	O6—C6—C7—O7	−179.55 (13)
C5—N1—C2—O3	9.64 (18)	C5—C6—C7—O7	59.78 (17)
O2—C2—O3—C4	−172.31 (14)	O3—C4—C8—C9	−67.09 (16)
N1—C2—O3—C4	6.88 (17)	C5—C4—C8—C9	173.19 (13)
C2—O3—C4—C8	−147.84 (12)	C4—C8—C9—C10	−178.45 (14)
C2—O3—C4—C5	−19.08 (15)	C8—C9—C10—C11	175.90 (14)
C2—N1—C5—C6	105.62 (15)	C9—C10—C11—C12	179.56 (14)
C2—N1—C5—C4	−20.13 (16)	C10—C11—C12—C13	178.45 (14)
O3—C4—C5—N1	22.39 (14)	C11—C12—C13—C14	179.32 (14)
C8—C4—C5—N1	144.21 (14)	C12—C13—C14—C15	179.81 (15)
O3—C4—C5—C6	−99.94 (15)	C13—C14—C15—C16	179.16 (15)
C8—C4—C5—C6	21.9 (2)	C14—C15—C16—C17	−178.97 (14)
N1—C5—C6—O6	−58.29 (15)	C15—C16—C17—C18	179.19 (15)
C4—C5—C6—O6	56.21 (17)	C16—C17—C18—C19	−177.59 (14)
N1—C5—C6—C7	62.64 (17)	C17—C18—C19—C20	178.74 (15)
C4—C5—C6—C7	177.14 (14)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O7^i	0.85 (2)	2.07 (2)	2.9005 (17)	167.2 (18)
O6—H6O···O7^ii	0.88 (2)	2.25 (2)	3.1025 (17)	165 (2)
O7—H7O···O2^iii	0.77 (3)	1.95 (3)	2.6997 (17)	161 (2)

Symmetry codes: (i) −x+3, y−1/2, −z+2; (ii) x−1, y, z; (iii) x, y+1, z.