threo-2-(2,6-Dimethoxy­phen­oxy)-1-(4-hydr­oxy-3,5-dimethoxy­phenyl)­propane-1,3-diol: a conformational study

In the crystal structure of the title compound, C₁₉H₂₄O₈, the mol­ecules adopt a conformation in which the bulky 2,6-dimethoxy­phen­oxy and 4-hydr­oxy-3,5-dimethoxy­phen­yl groups are almost as far apart as possible. The C(aryl)...C(aryl) distance is 4.8766 (19) Å, which is close to the calculated maximum value (4.92 Å). The C(aryl)-C-C-O(aryloxy) torsion angle is 173.76 (11)° and the C(benzylic)-C-O-C(aryl) torsion angle is 149.09 (11)°. The conformation is compared with those of related lignin model compounds. The hydrogen-bonding pattern is discussed in terms of graph-set theory.

S1. Comment

This paper describes the crystal structure of the title threo form, (I), of a lignin model compound representative of structural elements in lignin of the arylglycerol β-syringyl ether type. The crystal structure of the erythro form, (II), has been reported previously (Langer, Li & Lundquist, 2002). Arylglycerol β-syringyl ethers constitute a major type of structural element in hardwood lignins, e.g. in birch lignin (Larsson & Miksche, 1971). The erythro form of such structural elements predominates (Lundquist & von Unge, 1986; Bardet et al., 1998; Akiyama et al., 2003).

In (I), the C9—C10—O6—C12 torsion angle is 149.09 (11)° and the C1—C9—C10—O6 torsion angle is 173.76 (11)° (the enantiomer with the R configuration at the benzylic C atom is considered throughout the discussion of torsion angles in this paper). The C1···C12 distance is 4.8766 (19) Å. In the erythro form, (II), the corresponding data are −75.26 (13)°, −177.27 (10)° and 4.4458 (17) Å, respectively. The C1···C12 distance in (II) is about the same as the corresponding distances in other examined erythro forms of the arylglycerol β-syringyl ether type (Stomberg & Lundquist, 1989; Langer & Lundquist, 2001; Langer et al., 2005). Obviously, the aromatic rings in the erythro form, (II) (and related compounds), are not separated as much as they are in the threo form, (I). The angle between the aromatic ring planes is 67.66 (6)° in (I) and 57.27 (5)° in (II). The C1···C12 distance in (I) [4.8766 (1)9 Å] is very close to the calculated maximum value (4.92 Å).

In the crystal structure of (I), there are three intramolecular (Fig. 1) and two intermolecular hydrogen bonds of the O—H···O type and four intermolecular hydrogen bonds of the weak C—H···O type (Table 1). On the first-level graph-set (Bernstein et al., 1995; Grell et al., 1999), the intramolecular hydrogen bonds are classified as S(5) for bonds a and c, and S(8) for d (Fig. 1). The intermolecular hydrogen bonds b and e form C(10) and C(6) chains, respectively (Fig 2). The weak intramolecular hydrogen bonds f, g, h and i form R₂²(8) rings and C(8), C(13) and C(7) chains, respectively. On the second-level graph-set, many chains and rings could be identified, the most important ones being C₂²(10) and C₂²(16) chain types, both formed by bonds b and e. These two hydrogen bonds thus form R₃³(22) rings (Fig 2). The assignment of graph-set descriptors was performed using PLUTO, as described by Motherwell et al. (1999). The hydrogen-bonding patterns of threo (I) and erythro (II) (Langer, Li & Lundquist, 2002) are similar with respect to intramolecular hydrogen bonds.

As pointed out above, the title threo β-syringyl ether, (I), adopts a conformation in which the aryl groups are almost as far apart as possible. This is actually what could be expected from computational studies (Besombes et al., 2003a). In a second threo fom of an arylglycerol β-syringyl ether, threo- 2-(2,6-dimethoxyphenoxy)-1-(3,4-dimethoxyphenoxy)-1,3-propanediol, the C(aryl)—C—C—O(aryloxy) torsion angle is −70.5 (2)° and the C(aryl)-O—C—C(benzylic) torsion angle is −148.25 (19)° (Langer, Lundquist et al., 2002). This leads to a C(aryl)···C(aryl) distance of 4.319 (3) Å, which deviates significantly from the maximum value (ca 5 Å). However, according to computational studies, the conformation adopted by this compound is fairly favoured (Besombes et al., 2003a). All the threo forms of models of the arylglycerol β-guaiacyl ether type which have been examined to date [(III) (Stomberg et al., 1988); (IV) and its triacetate (Lundquist et al., 1996); (V) (Langer & Lundquist, 2002)] adopt conformations in which the aromatic groups are far apart from each other. This is in accordance with expectations based on computational studies (Simon & Eriksson, 1998; Besombes et al., 2003b). The crystal structure of the threo form of a trimeric model compound of the arylglyderol β-aryl ether type, (VI), has been reported by Karhunen et al. (1996). Calculations based on their data show that this compound also adopts an extended conformation: the C(aryl)—C—C—O(aryloxy) torsion angle is 175.7° and the C(aryl)—O—C—C(benzylic) torsion angle is 171.9°.

S2. Experimental

threo-2-(2,6-Dimethoxyphenoxy)-1-(4-hydroxy-3,5- dimethoxyphenyl)-1,3-propanediol, (I), was synthesized according to the procedure given by Li et al. (2000). Separation of the erythro and threo forms was accomplished by ion-exchange chromatography (cf. Li et al., 1994). For (I), m.p. 415–417 K. Crystals of (I) suitable for X-ray crystallography were obtained from 2-butanone/ethyl acetate (Ratio?).

S3. Refinement

H atoms were refined isotropically and were constrained to the ideal geometry using an appropriate riding model. For aromatic H atoms, the C—H distance was kept fixed at 0.95 Å, for secondary H atoms at 0.99 Å and for tertiary at 1.00 Å. For the hydroxyl groups, the O—H distance (0.84 Å) and C—O—H angle (109.5°) were kept fixed, while the torsion angle was allowed to refine, with the starting position based on the circular Fourier synthesis. For methyl groups, the C—H distances (0.98 Å) and C—C—H angles (109.5°) were kept fixed, while the torsion angles were allowed to refine, with the starting position based on the threefold averaged circular Fourier synthesis.

Computing details

Data collection: SMART(Siemens, 1995); cell refinement: SAINT (Siemens, 1995); data reduction: SAINT and SADABS (Sheldrick, 2002; program(s) used to solve structure: SHELXTL (Bruker, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: DIAMOND (Brandenburg, 2005); software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. A perspective drawing of (I), showing the atom-numbering scheme. Displacement ellipsoids are shown at the 50% probability level. The intramolecular hydrogen bonds are shown as broken lines and their notation is given in Table 1.
	Fig. 2. The hydrogen-bonding pattern of (I) in projection along the c axis. The hydrogen-bond notation is given in Table 1.

threo-2-(2,6-Dimethoxyphenoxy)-1-(4-hydroxy-3,5-dimethoxyphenyl)propane- 1,3-diol

Crystal data

C19H24O8	F(000) = 1616
Mr = 380.38	Dx = 1.398 Mg m^−3
Monoclinic, C2/c	Melting point = 415–417 K
Hall symbol: -C 2yc	Mo Kα radiation, λ = 0.71073 Å
a = 24.0634 (1) Å	Cell parameters from 7395 reflections
b = 7.3465 (1) Å	θ = 1.9–30.7°
c = 22.4459 (3) Å	µ = 0.11 mm^−1
β = 114.332 (1)°	T = 173 K
V = 3615.56 (7) Å^3	Prism, colourless
Z = 8	0.28 × 0.24 × 0.22 mm

Data collection

Siemens SMART CCD area-detector diffractometer	5566 independent reflections
Radiation source: fine-focus sealed tube	4423 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.035
ω scans	θmax = 30.7°, θmin = 1.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 2002)	h = −34→34
Tmin = 0.758, Tmax = 0.976	k = −10→10
28856 measured reflections	l = −32→32

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.050	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.146	H-atom parameters constrained
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0693P)^2 + 4.0089P] where P = (Fo^2 + 2Fc^2)/3
5566 reflections	(Δ/σ)max = 0.001
275 parameters	Δρmax = 0.55 e Å^−3
0 restraints	Δρmin = −0.27 e Å^−3

Special details

Experimental. Data were collected at low temperature using a Siemens SMART CCD diffractometer equiped with a LT-2 device. A full sphere of reciprocal space was scanned by 0.3° steps in ω with a crystal–to–detector distance of 3.97 cm, 20 s per frame. Preliminary orientation matrix was obtained from the first 100 frames using SMART (Siemens, 1995). The collected frames were integrated using the preliminary orientation matrix which was updated every 100 frames. Final cell parameters were obtained by refinement on the position of 7395 reflections with I>10σ(I) after integration of all the frames data using SAINT (Siemens, 1995).

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 (Ų)

	x	y	z	Uiso*/Ueq
O1	1.26067 (5)	0.57058 (19)	0.93706 (5)	0.0342 (3)
O2	1.33164 (5)	0.60577 (18)	0.87428 (5)	0.0332 (3)
H2	1.3495	0.6196	0.8494	0.044 (6)*
O3	1.28640 (5)	0.63279 (19)	0.74418 (6)	0.0350 (3)
O4	1.05517 (5)	0.77079 (14)	0.69355 (6)	0.0324 (3)
H4	1.0226	0.7506	0.6606	0.056 (7)*
O5	1.07439 (5)	0.13622 (14)	0.66710 (5)	0.0265 (2)
H5	1.0704	0.0297	0.6783	0.067 (8)*
O6	0.98651 (4)	0.45885 (13)	0.66054 (4)	0.01855 (19)
O7	0.97078 (5)	0.67472 (15)	0.56114 (5)	0.0296 (2)
O8	0.93480 (5)	0.13097 (15)	0.64410 (6)	0.0311 (2)
C1	1.14385 (6)	0.61084 (19)	0.76799 (7)	0.0230 (3)
C2	1.16891 (6)	0.59072 (19)	0.83541 (7)	0.0239 (3)
H2A	1.1430	0.5774	0.8576	0.027 (5)*
C3	1.23207 (6)	0.5899 (2)	0.87086 (7)	0.0251 (3)
C4	1.27024 (6)	0.6081 (2)	0.83844 (7)	0.0249 (3)
C5	1.24446 (6)	0.6239 (2)	0.77060 (7)	0.0252 (3)
C6	1.18159 (6)	0.6279 (2)	0.73525 (7)	0.0255 (3)
H6	1.1646	0.6423	0.6891	0.029 (5)*
C7	1.22344 (9)	0.5300 (3)	0.97058 (9)	0.0460 (5)
H7A	1.1946	0.6298	0.9644	0.057 (7)*
H7B	1.2491	0.5151	1.0173	0.060 (7)*
H7C	1.2009	0.4171	0.9532	0.058 (7)*
C8	1.26462 (8)	0.6151 (3)	0.67552 (8)	0.0351 (4)
H8A	1.2415	0.5015	0.6615	0.048 (6)*
H8B	1.2992	0.6133	0.6631	0.052 (7)*
H8C	1.2380	0.7184	0.6543	0.054 (7)*
C9	1.07530 (6)	0.60671 (19)	0.73068 (7)	0.0220 (3)
H9	1.0566	0.6007	0.7630	0.023 (4)*
C10	1.05236 (6)	0.44501 (18)	0.68448 (6)	0.0189 (2)
H10	1.0643	0.4615	0.6471	0.022 (4)*
C11	1.07503 (7)	0.26098 (19)	0.71608 (7)	0.0241 (3)
H11A	1.1170	0.2728	0.7504	0.044 (6)*
H11B	1.0484	0.2156	0.7367	0.031 (5)*
C12	0.95217 (6)	0.39685 (18)	0.59825 (6)	0.0192 (2)
C13	0.94180 (6)	0.5109 (2)	0.54514 (7)	0.0235 (3)
C14	0.90435 (8)	0.4543 (2)	0.48201 (7)	0.0334 (3)
H14	0.8973	0.5309	0.4455	0.044 (6)*
C15	0.87777 (8)	0.2844 (3)	0.47373 (8)	0.0367 (4)
H15	0.8528	0.2441	0.4307	0.048 (6)*
C16	0.88619 (7)	0.1714 (2)	0.52561 (8)	0.0305 (3)
H16	0.8667	0.0560	0.5184	0.040 (6)*
C17	0.92351 (6)	0.22747 (19)	0.58878 (7)	0.0231 (3)
C18	0.96536 (10)	0.7951 (2)	0.50902 (9)	0.0396 (4)
H18A	0.9832	0.7378	0.4815	0.043 (6)*
H18B	0.9870	0.9089	0.5272	0.058 (7)*
H18C	0.9222	0.8213	0.4826	0.052 (7)*
C19	0.90465 (9)	−0.0389 (2)	0.63792 (10)	0.0365 (4)
H19A	0.8604	−0.0205	0.6161	0.037 (5)*
H19B	0.9151	−0.0909	0.6814	0.058 (7)*
H19C	0.9176	−0.1224	0.6120	0.046 (6)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0231 (5)	0.0535 (7)	0.0231 (5)	−0.0006 (5)	0.0067 (4)	0.0049 (5)
O2	0.0157 (5)	0.0538 (7)	0.0264 (5)	−0.0008 (5)	0.0050 (4)	0.0034 (5)
O3	0.0205 (5)	0.0563 (8)	0.0282 (5)	−0.0051 (5)	0.0100 (4)	−0.0018 (5)
O4	0.0255 (5)	0.0190 (5)	0.0407 (6)	−0.0022 (4)	0.0017 (5)	−0.0004 (4)
O5	0.0275 (5)	0.0202 (5)	0.0326 (5)	0.0014 (4)	0.0133 (4)	−0.0006 (4)
O6	0.0140 (4)	0.0221 (5)	0.0177 (4)	−0.0009 (3)	0.0046 (3)	−0.0025 (3)
O7	0.0373 (6)	0.0234 (5)	0.0270 (5)	0.0005 (4)	0.0123 (4)	0.0069 (4)
O8	0.0358 (6)	0.0250 (5)	0.0321 (6)	−0.0112 (4)	0.0136 (5)	−0.0004 (4)
C1	0.0183 (6)	0.0209 (6)	0.0274 (7)	−0.0010 (5)	0.0070 (5)	−0.0025 (5)
C2	0.0205 (6)	0.0233 (6)	0.0279 (7)	−0.0011 (5)	0.0100 (5)	−0.0023 (5)
C3	0.0215 (6)	0.0273 (7)	0.0234 (6)	−0.0005 (5)	0.0060 (5)	−0.0002 (5)
C4	0.0174 (6)	0.0266 (7)	0.0270 (7)	−0.0014 (5)	0.0055 (5)	−0.0004 (5)
C5	0.0193 (6)	0.0275 (7)	0.0281 (7)	−0.0035 (5)	0.0091 (5)	−0.0017 (5)
C6	0.0205 (6)	0.0293 (7)	0.0242 (6)	−0.0027 (5)	0.0065 (5)	−0.0011 (5)
C7	0.0334 (9)	0.0759 (15)	0.0272 (8)	−0.0074 (9)	0.0109 (7)	0.0087 (9)
C8	0.0296 (8)	0.0479 (10)	0.0304 (8)	−0.0054 (7)	0.0148 (6)	−0.0041 (7)
C9	0.0170 (6)	0.0218 (6)	0.0250 (6)	−0.0019 (5)	0.0066 (5)	−0.0032 (5)
C10	0.0142 (5)	0.0214 (6)	0.0201 (6)	0.0004 (4)	0.0062 (4)	0.0002 (5)
C11	0.0238 (6)	0.0219 (6)	0.0242 (6)	0.0045 (5)	0.0074 (5)	0.0021 (5)
C12	0.0159 (5)	0.0215 (6)	0.0187 (6)	0.0012 (4)	0.0055 (4)	−0.0020 (5)
C13	0.0231 (6)	0.0248 (6)	0.0215 (6)	0.0046 (5)	0.0082 (5)	0.0008 (5)
C14	0.0338 (8)	0.0411 (9)	0.0197 (6)	0.0096 (7)	0.0056 (6)	0.0017 (6)
C15	0.0296 (8)	0.0461 (10)	0.0240 (7)	0.0041 (7)	0.0006 (6)	−0.0116 (7)
C16	0.0224 (7)	0.0304 (7)	0.0336 (8)	−0.0027 (5)	0.0063 (6)	−0.0123 (6)
C17	0.0190 (6)	0.0234 (6)	0.0262 (6)	−0.0007 (5)	0.0086 (5)	−0.0031 (5)
C18	0.0551 (11)	0.0316 (8)	0.0412 (9)	0.0136 (8)	0.0291 (8)	0.0161 (7)
C19	0.0396 (9)	0.0227 (7)	0.0542 (10)	−0.0083 (6)	0.0261 (8)	−0.0040 (7)

Geometric parameters (Å, º)

O1—C3	1.3635 (18)	C7—H7B	0.9800
O1—C7	1.419 (2)	C7—H7C	0.9800
O2—C4	1.3605 (17)	C8—H8A	0.9800
O2—H2	0.8400	C8—H8B	0.9800
O3—C5	1.3666 (18)	C8—H8C	0.9800
O3—C8	1.415 (2)	C9—C10	1.5230 (19)
O4—C9	1.4316 (18)	C9—H9	1.0000
O4—H4	0.8400	C10—C11	1.5197 (19)
O5—C11	1.4266 (17)	C10—H10	1.0000
O5—H5	0.8400	C11—H11A	0.9900
O6—C12	1.3758 (15)	C11—H11B	0.9900
O6—C10	1.4520 (15)	C12—C13	1.3928 (19)
O7—C13	1.3631 (19)	C12—C17	1.3958 (19)
O7—C18	1.4291 (19)	C13—C14	1.393 (2)
O8—C17	1.3567 (18)	C14—C15	1.380 (3)
O8—C19	1.4211 (18)	C14—H14	0.9500
C1—C2	1.387 (2)	C15—C16	1.376 (3)
C1—C6	1.389 (2)	C15—H15	0.9500
C1—C9	1.5118 (18)	C16—C17	1.392 (2)
C2—C3	1.3952 (19)	C16—H16	0.9500
C2—H2A	0.9500	C18—H18A	0.9800
C3—C4	1.394 (2)	C18—H18B	0.9800
C4—C5	1.392 (2)	C18—H18C	0.9800
C5—C6	1.3891 (19)	C19—H19A	0.9800
C6—H6	0.9500	C19—H19B	0.9800
C7—H7A	0.9800	C19—H19C	0.9800
C3—O1—C7	117.02 (12)	C10—C9—H9	108.3
C4—O2—H2	109.5	O6—C10—C11	111.23 (11)
C5—O3—C8	117.39 (12)	O6—C10—C9	103.38 (10)
C9—O4—H4	109.5	C11—C10—C9	114.61 (11)
C11—O5—H5	109.5	O6—C10—H10	109.1
C12—O6—C10	117.38 (10)	C11—C10—H10	109.1
C13—O7—C18	117.83 (13)	C9—C10—H10	109.1
C17—O8—C19	117.89 (13)	O5—C11—C10	108.91 (11)
C2—C1—C6	120.11 (13)	O5—C11—H11A	109.9
C2—C1—C9	119.14 (12)	C10—C11—H11A	109.9
C6—C1—C9	120.71 (13)	O5—C11—H11B	109.9
C1—C2—C3	120.30 (13)	C10—C11—H11B	109.9
C1—C2—H2A	119.9	H11A—C11—H11B	108.3
C3—C2—H2A	119.9	O6—C12—C13	119.44 (12)
O1—C3—C2	124.34 (13)	O6—C12—C17	120.15 (12)
O1—C3—C4	115.71 (12)	C13—C12—C17	120.17 (12)
C2—C3—C4	119.95 (13)	O7—C13—C12	114.44 (12)
O2—C4—C5	122.26 (13)	O7—C13—C14	125.30 (14)
O2—C4—C3	118.61 (13)	C12—C13—C14	120.26 (14)
C5—C4—C3	119.11 (13)	C15—C14—C13	118.47 (15)
O3—C5—C6	125.19 (13)	C15—C14—H14	120.8
O3—C5—C4	113.73 (12)	C13—C14—H14	120.8
C6—C5—C4	121.07 (13)	C14—C15—C16	122.25 (14)
C5—C6—C1	119.43 (13)	C14—C15—H15	118.9
C5—C6—H6	120.3	C16—C15—H15	118.9
C1—C6—H6	120.3	C17—C16—C15	119.46 (15)
O1—C7—H7A	109.5	C17—C16—H16	120.3
O1—C7—H7B	109.5	C15—C16—H16	120.3
H7A—C7—H7B	109.5	O8—C17—C16	125.42 (14)
O1—C7—H7C	109.5	O8—C17—C12	115.24 (12)
H7A—C7—H7C	109.5	C16—C17—C12	119.35 (14)
H7B—C7—H7C	109.5	O7—C18—H18A	109.5
O3—C8—H8A	109.5	O7—C18—H18B	109.5
O3—C8—H8B	109.5	H18A—C18—H18B	109.5
H8A—C8—H8B	109.5	O7—C18—H18C	109.5
O3—C8—H8C	109.5	H18A—C18—H18C	109.5
H8A—C8—H8C	109.5	H18B—C18—H18C	109.5
H8B—C8—H8C	109.5	O8—C19—H19A	109.5
O4—C9—C1	109.63 (11)	O8—C19—H19B	109.5
O4—C9—C10	108.64 (11)	H19A—C19—H19B	109.5
C1—C9—C10	113.54 (11)	O8—C19—H19C	109.5
O4—C9—H9	108.3	H19A—C19—H19C	109.5
C1—C9—H9	108.3	H19B—C19—H19C	109.5
C6—C1—C2—C3	0.8 (2)	O4—C9—C10—O6	−63.99 (13)
C9—C1—C2—C3	178.55 (13)	C1—C9—C10—O6	173.76 (11)
C7—O1—C3—C2	6.8 (2)	O4—C9—C10—C11	174.79 (11)
C7—O1—C3—C4	−172.67 (16)	C1—C9—C10—C11	52.54 (16)
C1—C2—C3—O1	−179.87 (14)	O6—C10—C11—O5	88.62 (13)
C1—C2—C3—C4	−0.4 (2)	C9—C10—C11—O5	−154.57 (11)
O1—C3—C4—O2	−0.1 (2)	C10—O6—C12—C13	−83.77 (15)
C2—C3—C4—O2	−179.61 (14)	C10—O6—C12—C17	101.89 (14)
O1—C3—C4—C5	178.41 (14)	C18—O7—C13—C12	176.37 (13)
C2—C3—C4—C5	−1.1 (2)	C18—O7—C13—C14	−3.7 (2)
C8—O3—C5—C6	−10.8 (2)	O6—C12—C13—O7	3.51 (18)
C8—O3—C5—C4	168.63 (15)	C17—C12—C13—O7	177.85 (12)
O2—C4—C5—O3	1.2 (2)	O6—C12—C13—C14	−176.40 (13)
C3—C4—C5—O3	−177.24 (14)	C17—C12—C13—C14	−2.1 (2)
O2—C4—C5—C6	−179.30 (14)	O7—C13—C14—C15	−179.48 (15)
C3—C4—C5—C6	2.2 (2)	C12—C13—C14—C15	0.4 (2)
O3—C5—C6—C1	177.57 (15)	C13—C14—C15—C16	1.2 (3)
C4—C5—C6—C1	−1.8 (2)	C14—C15—C16—C17	−1.1 (3)
C2—C1—C6—C5	0.3 (2)	C19—O8—C17—C16	−2.3 (2)
C9—C1—C6—C5	−177.40 (13)	C19—O8—C17—C12	177.10 (13)
C2—C1—C9—O4	123.33 (14)	C15—C16—C17—O8	178.82 (15)
C6—C1—C9—O4	−58.97 (17)	C15—C16—C17—C12	−0.6 (2)
C2—C1—C9—C10	−114.96 (14)	O6—C12—C17—O8	−3.02 (18)
C6—C1—C9—C10	62.73 (18)	C13—C12—C17—O8	−177.32 (12)
C12—O6—C10—C11	−87.44 (13)	O6—C12—C17—C16	176.42 (12)
C12—O6—C10—C9	149.09 (11)	C13—C12—C17—C16	2.1 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O3	0.84	2.22	2.6707 (16)	114
O2—H2···O5^i	0.84	2.02	2.7851 (15)	152
O5—H5···O4^ii	0.84	1.99	2.8284 (15)	173
O4—H4···O6	0.84	2.31	2.7424 (14)	112
O4—H4···O7	0.84	2.13	2.9123 (16)	154
C9—H9···O6^iii	1.00	2.56	3.5139 (17)	159
C18—H18C···O2^iv	0.98	2.57	3.466 (2)	153
C19—H19C···O7^ii	0.98	2.52	3.491 (2)	169
C11—H11A···O3^v	0.99	2.50	3.2171 (18)	129

Symmetry codes: (i) −x+5/2, y+1/2, −z+3/2; (ii) x, y−1, z; (iii) −x+2, y, −z+3/2; (iv) x−1/2, −y+3/2, z−1/2; (v) −x+5/2, y−1/2, −z+3/2.