Methyl 3,6-di-O-pivaloyl-α-D-manno­pyran­oside

The X-ray crystal structure analysis of the title compound, C₁₇H₃₀O₈, revealed a ⁴C₁ conformation of the pyran­osyl ring [Cremer–Pople puckering parameters of Q = 0.568 (2) Å, θ = 5.1 (2) and φ = 218 (3)°]. The structure shows no deviations from the geometric parameters of pyran­oside carbohydrates. The hydroxyl groups participate in O—H...O hydrogen bonds, forming a two-dimensional pattern [O...O = 2.811 (3) and 2.995 (3) Å].

S1. Comment

The methyl α-glycosides of glucose, mannose and galactose constitute a valuable series of compounds in the study of hydrogen-bonding patterns and conformational stability in pyranose sugars and their derivatives. Other factors, such as van der Waals and dipole interactions and the shape and size of the substituents on the sugar residues, also play an important role in the determination of molecular packing.

Regioselective acylation of sugars is rarely carried out with efficiency. Therefore, the selective pivaloylations of methyl α-D-glycosides receive much attention in carbohydrate chemistry, as do selective enzymatic deacylations of such compounds. Migrations of the pivaloyl group have also been observed, and these intramolecular transesterifications in reactions catalyzed by esterases from some mammalian sera have been studied by Tomić (1999).

The structure determination of the title compound. (I), as the major product of the pivaloylation of methyl α-D-mannopyranoside (Trojko, 1999), was undertaken in order to investigate the conformation of the pyranoside ring and the hydrogen-bonding pattern in the solid state.

The main conformational feature of the pyranosyl ring in (I) is the expected ⁴C₁ conformation, with a slightly distorted chair geometry, as shown by the range of the ring torsion angles [53.3 (3)–58.3 (2)°]. Thes values can be compared with 60° for an ideal chair conformation and 55.8–61.7° for an ideal pyranose ring (Kim & Jeffrey, 1967). The Cremer & Pople (1975) puckering parameters [Q=0.568 (2) Å, θ=5.1 (2) and ϕ=218 (3)°] are analogous to those found for other mannose derivatives in the Cambridge Structural Database (Version 5.23; Allen, 2002).

The Csp³—Csp³ bond lengths within the pyranosyl moiety range from 1.505 (3) to 1.531 (3) Å [(mean = 1.518 (4) Å], which agrees with the values reported for other carbohydrates (Jeffrey, 1990; Allen et al., 1987). The external C5—C6 bond is short [1.505 (3) Å] and the ring C4—C5 distance is long [1.531 (3) Å]. The Csp³—O bond distances, however, show a greater variation, ranging between 1.405 (3) and 1.447 (3) Å.

The anomeric C1—O1 bond [1.405 (3) Å] is slightly shorter than the endocyclic C1—O5 and C5—O5 bonds [1.414 (3) and 1.433 (3) Å], as is found in pyranosidic compounds. These bond lengths, which are related to the acetal sequence C5—O5—C1—O1—C7, are ascribed to the anomeric effect and are consistent with observations in many α- and β-pyranoses. A systematic survey of this geometry in α-anomers of hexapyranosides gave the following average values: C1—O1 = 1.398, C1—O5 = 1.419 and C5—O5 = 1.434 Å (Jeffrey, 1990; Jeffrey & Taylor, 1980), or C1—O1 = 1.413((2), C1—O5 = 1.418 (1) and C5—O5 = 1.439 (2) Å (Allen & Fortier, 1993). The exocyclic C—O bonds in (I) are in the range 1.405 (3)–1.447 (3) Å [mean = 1.427 (9) Å]. The two O—H bonds are 0.82 (5) and 0.78 (3) Å.

The crystal structure is dominated by a two-dimensional network of O—H···O-type hydrogen bonds and involves free hydroxyl groups: OH4 acts both as a donor and as an acceptor, whereas OH2 acts only as a donor (Table 2 and Fig. 2). The OH4 H atom appears to be hydrogen bonded to O9(2 − x, −1/2 + y, 1/2 − z) at a distance of 2.23 (3) Å, with the two O atoms subtending an angle of 167 (3)°. The associated O4^···O9 distance is 2.995 (3) Å. The OH2 H atom is hydrogen bonded to O4(−1 + x, y, z) at a distance of 2.08 (5) Å, with an OH2^···O4 angle of 149 (5)° and an O2^···O4 distance of 2.811 (3) Å. The resulting motif, in the formalism of graph-set analysis of hydrogen-bond patterns (Etter et al., 1990), is characterized as an R⁴₄(28) ring pattern. According to Jeffrey's (Jeffrey, 1990) investigation, cyclic hydrogen-bonded systems are rare in mono- and disaccharide crystal structures.

In addition, a short intramolecular C—H^···O hydrogen bond occurs in (I). Atom C6 acts as hydrogen-bond donor and O4 as hydrogen-bond acceptor (Table 2). This C—H^···O contact, where H and O are separated by four covalent bonds, is characterized as S(5) according to Etter's classification (Etter et al., 1990). These interactions are a structural characteristic of the carbohydrates. Because of the conformational flexibility, the geometric parameters of C—H^···O contacts may vary over considerable ranges [the mean values are H^···O = 2.60, C^···O = 2.92 Å and C—H^···O = 96°; Steiner & Saenger, 1992]. Several other C—H^···O interactions in (I), which include methyl C atoms, exhibit geometrical parameters similar to these reported average values (with angles ranging from 93 to 100°), but these interactions are not included in Table 2.

The calculated density is 1.194 g cm⁻³, which is significantly lower than that of carbohydrates with free OH groups, e.g. 1.412 g cm⁻³ in 3-deoxy-methyl-α-D-mannopyranoside (Evdokimov & Frolow, 1997), 1.416 g cm⁻³ in methyl α-L-mannopyranoside (Shalaby et al., 1994a), 1.461 g cm⁻³ in methyl α-D-mannopyranoside (Jeffrey et al., 1977) and 1.564 g cm⁻³ in α-D-mannopyranose (Longchambon et al., 1976), or the values reported for acylated monosaccharides, e.g. 1.244 g cm⁻³ in methyl 2,3,4-tri-O-acetyl-α-L-mannopyranoside (Shalaby et al., 1994b) and 1.324 g cm⁻³ in 1,2,3,4,6,7-hexa-O-acetyl-L-glycero-D-mannopyranoside (Duda et al., 1986). This fact points to a looser packing, probably caused by the bulky pivaloyl groups, which exhibit augmented displacements. Also, the intramolecular C—H^···O contacts mentioned above have no significant influence in reducing the thermal vibrations of the pivaloyl C atoms.

S2. Experimental

Compound (I) was synthesized as the major product (yield: 49%) in the acylation of methyl-α-D-mannopyranoside (485 mg, 2.5 mmol) with 5 equivalents of pivaloyl chloride (1.54 ml, 12.5 mmol). The mixture in dry pyridine (1.5 ml) was stirred at room temperature for 50 min, and the products were isolated by column chromatography on silica gel (Trojko, 1999). Colourless single crystals of adequate quality for diffraction analysis were obtained by evaporation from diisopropyl ether (m.p. = 362–364 K).

S3. Refinement

The tert-butyl group at C9 displays large displacement parameters, indicating the possible presence of positional disorder. Contoured electron-density Fourier maps were drawn at the final stages of refinement, in order to reveal possible multiple positions for the atoms C11–C13. Note that the reflections observed have very sharp maxima (R_int=0.0268). Since the contour map does not reveal a partial disorder of atoms C11, C12 and C13, and the maximum peak of residual electron density was 0.158 e Å⁻³, the ordered model was used in the final refinement. Most H atoms were visible in the difference maps but were placed at calculated positions and refined as riding atoms [U_iso(H) = 1.5 U_eq(C) for CH₃; U_iso(H) = 1.2 U_eq(C) for other atoms). The positions of the hydroxy H atoms were determined from difference electron-density maps and were refined freely along with individual U_iso parameters. The absolute configuration could not be determined from the diffraction data because of the absence of significant anomalous scatterers in the compound, and an attempt to confirm the absolute structure by the refinement of the Flack parameter (Flack, 1983) led to an inconclusive value (Flack & Bernardelli, 2000). Therefore, Friedel equivalents were merged in the final refinement, and the absolute structure was set in accordance with the known chirality of the methyl-α-D-mannopyranoside precursor.

Computing details

Data collection: STADI4 (Stoe & Cie, 1995); cell refinement: STADI4 (Stoe & Cie, 1995); data reduction: X-RED (Stoe & Cie, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON98 (Spek, 1998); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).

Figures

	Fig. 1. The molecular structure of (I), showing the atom-numbering scheme. Displacement ellipsoids are shown at the 30% probability level.
	Fig. 2. Part of the crystal packing, with the hydrogen-bonding network shown as dashed lines. Only those H atoms involved in the interactions are shown.

'methyl 3,6-di-O-pivaloyl-α-D-mannopyranoside'

Crystal data

C17H30O8	Dx = 1.194 Mg m^−3
Mr = 362.41	Melting point: 362-364 K K
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 38 reflections
a = 6.8711 (11) Å	θ = 10.1–17.8°
b = 15.231 (2) Å	µ = 0.09 mm^−1
c = 19.263 (3) Å	T = 293 K
V = 2016.0 (5) Å^3	Prism, colourless
Z = 4	0.55 × 0.35 × 0.30 mm
F(000) = 784

Data collection

Philips PW 1100 (upgraded by Stoe) diffractometer	Rint = 0.027
Radiation source: fine-focus sealed tube	θmax = 27.0°, θmin = 2.9°
Graphite monochromator	h = −8→8
ω–scans	k = −19→19
4972 measured reflections	l = −24→24
2487 independent reflections	5 standard reflections every 90 min
2268 reflections with I > 2σ(I)	intensity decay: 5.8%

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: geom & dmap
R[F^2 > 2σ(F^2)] = 0.043	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.120	w = 1/[σ^2(Fo^2) + (0.0646P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.93	(Δ/σ)max = 0.002
4343 reflections	Δρmax = 0.16 e Å^−3
242 parameters	Δρmin = −0.15 e Å^−3
0 restraints	Extinction correction: SHELXL, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0133 (16)

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

	x	y	z	Uiso*/Ueq
O1	0.5829 (3)	0.66392 (11)	0.00467 (9)	0.0473 (4)
O2	0.3784 (3)	0.72115 (15)	0.17042 (11)	0.0614 (6)
H22	0.283 (8)	0.752 (3)	0.165 (3)	0.15 (2)*
O3	0.6345 (3)	0.86347 (10)	0.15893 (8)	0.0464 (5)
O4	0.9835 (2)	0.76914 (13)	0.17472 (10)	0.0450 (4)
H44	0.973 (4)	0.807 (2)	0.2015 (15)	0.055 (10)*
O5	0.6528 (2)	0.59850 (11)	0.11202 (9)	0.0421 (4)
O6	0.9958 (3)	0.50237 (11)	0.12785 (8)	0.0506 (5)
O8	0.5792 (3)	0.93935 (11)	0.06213 (11)	0.0619 (6)
O9	0.9822 (3)	0.41165 (11)	0.21884 (11)	0.0557 (5)
C1	0.5184 (4)	0.64821 (16)	0.07276 (12)	0.0428 (6)
H1	0.3964	0.6150	0.0701	0.051*
C2	0.4747 (3)	0.73633 (17)	0.10589 (14)	0.0443 (6)
H2	0.3920	0.7715	0.0752	0.053*
C3	0.6659 (4)	0.78382 (15)	0.11952 (12)	0.0381 (6)
H3	0.7296	0.7978	0.0754	0.046*
C4	0.7998 (3)	0.72768 (15)	0.16369 (13)	0.0363 (6)
H4	0.7378	0.7159	0.2086	0.044*
C5	0.8350 (3)	0.64089 (15)	0.12557 (13)	0.0364 (6)
H5	0.9040	0.6517	0.0819	0.044*
C6	0.9492 (4)	0.57787 (14)	0.16991 (13)	0.0444 (6)
H6A	1.0676	0.6056	0.1863	0.053*
H6B	0.8727	0.5602	0.2099	0.053*
C7	0.5996 (5)	0.58572 (18)	−0.03506 (16)	0.0593 (8)
H7A	0.7032	0.5503	−0.0168	0.089*
H7B	0.6274	0.6004	−0.0825	0.089*
H7C	0.4796	0.5536	−0.0328	0.089*
C8	0.5914 (4)	0.93673 (15)	0.12454 (14)	0.0412 (6)
C9	1.0048 (4)	0.42383 (15)	0.15763 (15)	0.0458 (6)
C10	1.0504 (6)	0.35327 (19)	0.10514 (16)	0.0762 (11)
C14	0.5653 (4)	1.01546 (17)	0.17175 (14)	0.0497 (7)
C15	0.5406 (5)	0.9896 (2)	0.24774 (15)	0.0660 (9)
H15A	0.4307	0.9511	0.2523	0.099*
H15B	0.5196	1.0414	0.2752	0.099*
H15C	0.6558	0.9602	0.2636	0.099*
C16	0.7510 (7)	1.0699 (2)	0.1639 (2)	0.0895 (12)
H16A	0.7481	1.1180	0.1961	0.134*
H16B	0.7592	1.0922	0.1174	0.134*
H16C	0.8621	1.0336	0.1733	0.134*
C17	0.3844 (7)	1.0659 (2)	0.1481 (2)	0.1004 (15)
H17A	0.2717	1.0292	0.1531	0.151*
H17B	0.3990	1.0825	0.1003	0.151*
H17C	0.3692	1.1176	0.1761	0.151*
C11	1.0981 (11)	0.2692 (2)	0.1403 (2)	0.135 (2)
H11A	1.1100	0.2235	0.1063	0.203*
H11B	0.9964	0.2546	0.1724	0.203*
H11C	1.2189	0.2753	0.1649	0.203*
C12	1.2174 (11)	0.3839 (4)	0.0572 (3)	0.164 (3)
H12A	1.3323	0.3941	0.0844	0.246*
H12B	1.1802	0.4373	0.0342	0.246*
H12C	1.2436	0.3394	0.0232	0.246*
C13	0.8765 (14)	0.3443 (4)	0.0583 (4)	0.222 (5)
H13A	0.9039	0.3020	0.0227	0.333*
H13B	0.8483	0.4001	0.0373	0.333*
H13C	0.7663	0.3253	0.0849	0.333*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0533 (10)	0.0430 (10)	0.0458 (9)	0.0005 (9)	−0.0049 (8)	0.0000 (8)
O2	0.0394 (10)	0.0808 (15)	0.0640 (13)	0.0105 (10)	0.0124 (10)	0.0046 (11)
O3	0.0582 (11)	0.0348 (9)	0.0462 (9)	0.0157 (8)	−0.0013 (9)	−0.0035 (8)
O4	0.0348 (9)	0.0423 (10)	0.0578 (11)	0.0018 (9)	−0.0022 (9)	−0.0092 (9)
O5	0.0401 (9)	0.0346 (8)	0.0517 (10)	−0.0017 (8)	−0.0040 (9)	0.0029 (8)
O6	0.0695 (12)	0.0331 (9)	0.0493 (9)	0.0183 (9)	0.0020 (9)	0.0043 (8)
O8	0.0890 (16)	0.0446 (10)	0.0520 (12)	0.0126 (10)	−0.0018 (11)	0.0027 (9)
O9	0.0694 (13)	0.0407 (10)	0.0571 (12)	0.0041 (10)	0.0000 (11)	0.0095 (9)
C1	0.0351 (13)	0.0450 (14)	0.0483 (14)	0.0010 (12)	−0.0024 (12)	0.0023 (12)
C2	0.0358 (13)	0.0482 (15)	0.0488 (14)	0.0091 (12)	0.0004 (12)	0.0025 (12)
C3	0.0449 (14)	0.0311 (13)	0.0384 (13)	0.0083 (11)	0.0040 (11)	−0.0011 (11)
C4	0.0317 (12)	0.0331 (13)	0.0440 (14)	0.0000 (10)	0.0025 (11)	0.0007 (11)
C5	0.0324 (13)	0.0362 (13)	0.0405 (12)	0.0036 (10)	0.0021 (11)	0.0026 (11)
C6	0.0504 (16)	0.0348 (14)	0.0480 (15)	0.0096 (11)	−0.0009 (13)	−0.0002 (11)
C7	0.0651 (19)	0.0554 (18)	0.0574 (17)	0.0053 (16)	−0.0014 (15)	−0.0086 (14)
C8	0.0404 (14)	0.0334 (13)	0.0497 (16)	0.0049 (12)	−0.0014 (12)	−0.0018 (12)
C9	0.0466 (15)	0.0356 (14)	0.0552 (17)	0.0048 (12)	−0.0069 (15)	0.0057 (12)
C10	0.129 (3)	0.0381 (15)	0.0610 (18)	0.0199 (18)	−0.014 (2)	−0.0031 (14)
C14	0.0540 (16)	0.0381 (14)	0.0570 (16)	0.0112 (12)	−0.0093 (14)	−0.0114 (12)
C15	0.073 (2)	0.0659 (19)	0.0594 (16)	0.0155 (17)	0.0051 (15)	−0.0171 (15)
C16	0.123 (3)	0.067 (2)	0.078 (2)	−0.035 (2)	0.002 (2)	−0.011 (2)
C17	0.116 (3)	0.087 (3)	0.098 (3)	0.072 (3)	−0.036 (2)	−0.031 (2)
C11	0.263 (7)	0.051 (2)	0.093 (3)	0.060 (3)	0.006 (4)	−0.0003 (19)
C12	0.254 (8)	0.106 (4)	0.132 (4)	0.058 (4)	0.107 (5)	−0.004 (3)
C13	0.314 (10)	0.136 (5)	0.216 (7)	0.073 (6)	−0.184 (8)	−0.090 (5)

Geometric parameters (Å, º)

O1—C1	1.405 (3)	C7—H7C	0.9600
O1—C7	1.420 (3)	C8—C14	1.516 (3)
O2—C2	1.427 (3)	C9—C10	1.509 (4)
O2—H22	0.82 (5)	C10—C11	1.485 (5)
O3—C8	1.331 (3)	C10—C13	1.504 (7)
O3—C3	1.447 (3)	C10—C12	1.545 (7)
O4—C4	1.427 (3)	C14—C15	1.525 (4)
O4—H44	0.77 (3)	C14—C16	1.529 (5)
O5—C1	1.414 (3)	C14—C17	1.530 (4)
O5—C5	1.433 (3)	C15—H15A	0.9600
O6—C9	1.328 (3)	C15—H15B	0.9600
O6—C6	1.443 (3)	C15—H15C	0.9600
O8—C8	1.206 (3)	C16—H16A	0.9600
O9—C9	1.204 (3)	C16—H16B	0.9600
C1—C2	1.516 (3)	C16—H16C	0.9600
C1—H1	0.9800	C17—H17A	0.9600
C2—C3	1.522 (4)	C17—H17B	0.9600
C2—H2	0.9800	C17—H17C	0.9600
C3—C4	1.517 (3)	C11—H11A	0.9600
C3—H3	0.9800	C11—H11B	0.9600
C4—C5	1.531 (3)	C11—H11C	0.9600
C4—H4	0.9800	C12—H12A	0.9600
C5—C6	1.505 (3)	C12—H12B	0.9600
C5—H5	0.9800	C12—H12C	0.9600
C6—H6A	0.9700	C13—H13A	0.9600
C6—H6B	0.9700	C13—H13B	0.9600
C7—H7A	0.9600	C13—H13C	0.9600
C7—H7B	0.9600
C1—O1—C7	112.7 (2)	O9—C9—O6	123.8 (2)
C2—O2—H22	99 (4)	O9—C9—C10	125.0 (2)
C8—O3—C3	118.35 (18)	O6—C9—C10	111.2 (2)
C4—O4—H44	110 (2)	C11—C10—C13	111.8 (5)
C1—O5—C5	115.28 (17)	C11—C10—C9	110.8 (3)
C9—O6—C6	119.06 (19)	C13—C10—C9	107.6 (4)
O1—C1—O5	112.6 (2)	C11—C10—C12	111.7 (4)
O1—C1—C2	107.7 (2)	C13—C10—C12	105.0 (5)
O5—C1—C2	112.2 (2)	C9—C10—C12	109.9 (3)
O1—C1—H1	108.0	C8—C14—C15	112.6 (2)
O5—C1—H1	108.0	C8—C14—C16	105.7 (2)
C2—C1—H1	108.0	C15—C14—C16	109.1 (3)
O2—C2—C1	108.4 (2)	C8—C14—C17	108.3 (2)
O2—C2—C3	109.1 (2)	C15—C14—C17	108.9 (3)
C1—C2—C3	108.82 (18)	C16—C14—C17	112.1 (3)
O2—C2—H2	110.2	C14—C15—H15A	109.5
C1—C2—H2	110.2	C14—C15—H15B	109.5
C3—C2—H2	110.2	H15A—C15—H15B	109.5
O3—C3—C4	105.59 (19)	C14—C15—H15C	109.5
O3—C3—C2	111.09 (19)	H15A—C15—H15C	109.5
C4—C3—C2	110.62 (19)	H15B—C15—H15C	109.5
O3—C3—H3	109.8	C14—C16—H16A	109.5
C4—C3—H3	109.8	C14—C16—H16B	109.5
C2—C3—H3	109.8	H16A—C16—H16B	109.5
O4—C4—C3	111.75 (19)	C14—C16—H16C	109.5
O4—C4—C5	108.28 (18)	H16A—C16—H16C	109.5
C3—C4—C5	108.26 (19)	H16B—C16—H16C	109.5
O4—C4—H4	109.5	C14—C17—H17A	109.5
C3—C4—H4	109.5	C14—C17—H17B	109.5
C5—C4—H4	109.5	H17A—C17—H17B	109.5
O5—C5—C6	105.75 (18)	C14—C17—H17C	109.5
O5—C5—C4	109.77 (18)	H17A—C17—H17C	109.5
C6—C5—C4	111.14 (19)	H17B—C17—H17C	109.5
O5—C5—H5	110.0	C10—C11—H11A	109.5
C6—C5—H5	110.0	C10—C11—H11B	109.5
C4—C5—H5	110.0	H11A—C11—H11B	109.5
O6—C6—C5	107.77 (19)	C10—C11—H11C	109.5
O6—C6—H6A	110.2	H11A—C11—H11C	109.5
C5—C6—H6A	110.2	H11B—C11—H11C	109.5
O6—C6—H6B	110.2	C10—C12—H12A	109.5
C5—C6—H6B	110.2	C10—C12—H12B	109.5
H6A—C6—H6B	108.5	H12A—C12—H12B	109.5
O1—C7—H7A	109.5	C10—C12—H12C	109.5
O1—C7—H7B	109.5	H12A—C12—H12C	109.5
H7A—C7—H7B	109.5	H12B—C12—H12C	109.5
O1—C7—H7C	109.5	C10—C13—H13A	109.5
H7A—C7—H7C	109.5	C10—C13—H13B	109.5
H7B—C7—H7C	109.5	H13A—C13—H13B	109.5
O8—C8—O3	122.6 (2)	C10—C13—H13C	109.5
O8—C8—C14	124.3 (2)	H13A—C13—H13C	109.5
O3—C8—C14	113.0 (2)	H13B—C13—H13C	109.5
C7—O1—C1—O5	64.8 (3)	O4—C4—C5—C6	64.8 (2)
C7—O1—C1—C2	−170.9 (2)	C3—C4—C5—C6	−173.8 (2)
C5—O5—C1—O1	65.5 (3)	C9—O6—C6—C5	−146.7 (2)
C5—O5—C1—C2	−56.3 (3)	O5—C5—C6—O6	67.5 (2)
O1—C1—C2—O2	170.30 (19)	C4—C5—C6—O6	−173.41 (19)
O5—C1—C2—O2	−65.2 (2)	C3—O3—C8—O8	−0.6 (4)
O1—C1—C2—C3	−71.2 (2)	C3—O3—C8—C14	−179.1 (2)
O5—C1—C2—C3	53.3 (3)	C6—O6—C9—O9	−2.4 (4)
C8—O3—C3—C4	153.5 (2)	C6—O6—C9—C10	178.6 (3)
C8—O3—C3—C2	−86.5 (3)	O9—C9—C10—C11	−9.9 (6)
O2—C2—C3—O3	−54.8 (2)	O6—C9—C10—C11	169.0 (4)
C1—C2—C3—O3	−172.86 (19)	O9—C9—C10—C13	112.5 (5)
O2—C2—C3—C4	62.1 (2)	O6—C9—C10—C13	−68.6 (5)
C1—C2—C3—C4	−55.9 (3)	O9—C9—C10—C12	−133.8 (4)
O3—C3—C4—O4	−62.3 (2)	O6—C9—C10—C12	45.1 (4)
C2—C3—C4—O4	177.47 (18)	O8—C8—C14—C15	166.3 (3)
O3—C3—C4—C5	178.59 (18)	O3—C8—C14—C15	−15.2 (3)
C2—C3—C4—C5	58.3 (2)	O8—C8—C14—C16	−74.6 (4)
C1—O5—C5—C6	177.77 (18)	O3—C8—C14—C16	103.9 (3)
C1—O5—C5—C4	57.8 (2)	O8—C8—C14—C17	45.7 (4)
O4—C4—C5—O5	−178.52 (19)	O3—C8—C14—C17	−135.8 (3)
C3—C4—C5—O5	−57.2 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H22···O4^i	0.82 (5)	2.08 (5)	2.811 (3)	149 (5)
O4—H44···O9^ii	0.78 (3)	2.23 (3)	2.995 (3)	167 (3)
C6—H6A···O4	0.97	2.57	2.924 (3)	102

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