Methyl [beta]-D-galactopyranosyl-(1[rightwards arrow]4)-[beta]-D-allopyran­oside tetra­hydrate

The title compound, C₁₃H₂₄O₁₁·4H₂O, (I), crystallized from water, has an inter­nal glycosidic linkage conformation having [varphi]' (O5_Gal-C1_Gal-O1_Gal-C4_All) = -96.40 (12)° and [psi]' (C1_Gal-O1_Gal-C4_All-C5_All) = -160.93 (10)°, where ring-atom numbering conforms to the convention in which C1 denotes the anomeric C atom, C5 the ring atom bearing the exocyclic hydroxymethyl group, and C6 the exocyclic hy­droxy­methyl (CH₂OH) C atom in the [beta]Galp and [beta]Allp residues. Inter­nal linkage conformations in the crystal structures of the structurally related disaccharides methyl [beta]-lactoside [methyl [beta]-D-galactopyranosyl-(1[rightwards arrow]4)-[beta]-D-gluco­pyran­oside] methanol solvate [Stenutz, Shang & Serianni (1999). Acta Cryst. C55, 1719-1721], (II), and methyl [beta]-cello­bioside [methyl [beta]-D-gluco­pyran­osyl-(1[rightwards arrow]4)-[beta]-D-gluco­pyran­oside] methanol solvate [Ham & Williams (1970). Acta Cryst. B26, 1373-1383], (III), are characterized by [varphi]' = -88.4 (2)° and [psi]' = -161.3 (2)°, and [varphi]' = -91.1° and [psi]' = -160.7°, respectively. Inter-residue hydrogen bonding is observed between O3_Glc and O5_Gal/Glc in the crystal structures of (II) and (III), suggesting a role in determining their preferred linkage conformations. An analogous inter-residue hydrogen bond does not exist in (I) due to the axial orientation of O3_All, yet its inter­nal linkage conformation is very similar to those of (II) and (III).

S1. Comment

As a component of experimental and theoretical studies of the effects of primary structure and solvation on the conformations and dynamics of biologically important oligosaccharides, the title disaccharide, (I), was prepared with single sites of ¹³C-enrichment at either C1' or C2' to permit measurements of its constituent trans-glycoside J_CH and J_CC values (Bose et al., 1998; Cloran et al.,1999; Zhao et al., 2008). Disaccharide (I) is structurally related to methyl β-lactoside [methyl β-D-galactopyranosyl-(1→4)-β-D-glucopyranoside] methanol solvate, (II) (Stenutz et al., 1999), and methyl β-cellobioside [methyl β-D-glucopyranosyl-(1→4)-β-D-glucopyranoside] methanol solvate, (III) (Ham & Williams, 1970); these disaccharides differ only in the configuration at C3 and/or C4'. The structural differences at C3 occur near the internal glycosidic linkage, and thus might be expected to affect linkage conformation in solution and in the solid state. This situation contrasts with that involving structural changes at C2 discussed in a recent comparison of the crystal structures of methyl α-lactoside [methyl β-D-galactopyranosyl-(1→4)-α-D-glucopyranoside], (IV) (Pan et al., 2005), and methyl β-D-galactopyranosyl-(1→4)-α-D-mannopyranoside methanol 0.375-solvate, (V) (Hu et al., 2010). While the latter change is more remote from the internal linkage, X-ray crystal structures of (IV) and (V) show significant differences in linkage conformation. In solution, however, (IV) and (V) appear to assume virtually identical internal linkage conformations, based on analyses of trans-glycoside J-couplings (Klepach & Serianni, private communication). As shown herein, in the crystalline state the internal linkage conformations in (I) and (II) are very similar, whereas in solution the conformations differ (Klepach & Serianni, private communication). Overall results from (I)–(V) show that the structural characteristics of related disaccharides in the solid state cannot be expected to mimic those found in solution, due to the inherent flexibility of the glycosidic linkage and the effects of solvation and/or crystal packing forces in the solution and solid states, respectively.

An analysis of endocyclic C—C bond lengths in (I)–(III) shows that r_C1,C2 [1.523 (7) Å] [in the following discussion, averages were calculated using the appropriate molecular parameter in both residues of (I)–(III); e.g. for r_C1,C2, both r_C1,C2 and r_C1',C2' (total of six values) were used to obtain 1.523 (7) Å, where (7) is the standard deviation] is very similar to the remaining C—C bond lengths in the aldopyranosyl ring constituents [1.529 (5) Å], whereas r_C5,C6 is significantly shorter [1.513 (6) Å] than all the other endocyclic C—C bonds. These results compare very favorably with trends reported recently from structural comparisons of (IV), (V) and several methyl aldopyranosides (Hu et al., 2010), where values of 1.524 (6), 1.528 (7) and 1.518 (3) Å, respectively, were observed.

The endocyclic C—O bonds in (I)–(III) (i.e. r_C1,O5 and r_C5,O5) are 1.429 (7) Å, in good agreement with the value of 1.428 (9) Å observed in (IV), (V) and related monosaccharides (Hu et al., 2010). The exocyclic C—O bonds not involving the anomeric C atoms and other C atoms in a glycosidic linkage are 1.424 (9) and 1.426 (2) Å for equatorial and axial bonds, respectively; as reported previously (Hu et al., 2010), non-anomeric bond orientation exerts essentially no discernible effect on C—O bond length. The anomeric C1—O1 bonds (all equatorial) are 1.387 (6) Å for the βGalp and βGlcp residues of (I)–(III). In contrast, r_C1',O1' in (I) (βGalp residue) is 1.4014 (15) Å, which is lengthened relative to the remaining C—O bonds involving anomeric C atoms. The remaining C—O bonds, r_C4,O1', are 1.434 (5) Å, which is slightly longer than the other endocyclic equatorial C—O bonds in (I)–(III), although the elongation appears considerably reduced compared with observations made in (IV) and (V) (Hu et al., 2010).

The internal glycosidic C1'—O1'—C4 bond angles in (I)–(III) [115.6 (7)°] are larger than the related C1—O1—C7 bond angles [113.0 (7)°], presumably due to the greater steric demands of the internal linkage.

Inter-residue (intramolecular) hydrogen bonding is not observed in (I). In (II) and (III), the interatomic distance between atoms O3 and O5' of 2.763 (1) Å is consistent with the presence of a hydrogen bond between atoms O3H (donor) and O5' (acceptor). In (I), the corresponding distance is 3.448 Å.

The endocyclic torsion angles in the pyranosyl rings of (I)–(III) differ considerably from the idealized 60° expected for perfect ⁴C₁ chair forms; for example, torsion angles involving a terminal C1/C1' vary from 44 to 70° (absolute values) (Table 1). These deviations suggest the existence of ⁴C₁ chair forms that deviate from ideal conformations. Calculation of Cremer–Pople puckering parameters (Cremer & Pople, 1975) for the aldopyranosyl rings of (I)–(III) are given in Table 2. The extent of the distortion, embodied in θ, is smaller for the βGalp residues of (I) and (II) and the βAllp residue of (I) (θ values ranging from 2.4–4.7°) than for the βGlcp residues of (II) and (III) (θ values ranging from 10.0–12.7°). The direction of the distortion, embodied in ϕ, also varies widely. The βGalp, βGlcp and βGlcpOMe residues of (I), (II) and (III), respectively, have similar ϕ values [336 (5)°], suggesting a distortion towards ^OS₂ forms. The βAllp residue of (I), with ϕ near 70°, is distorted towards B_1,4, while the βGalp and βGlcp residues of (II) and (III) [ϕ = 24 (6)°] are distorted towards ³S₁. Overall, less pyranosyl ring distortion is observed in (I) than in (II) and (III), despite the presence of an axial atom O3 in the former.

The internal glycosidic torsion angles are very similar in (I)–(III): -92 (4)° for ϕ' (O5'—C1'—O1'—C4) and -161.0 (3)° for ψ' (C1'—O1'—C4—C5). The variability in ϕ' is considerably larger than that in ψ', which might be unexpected since ϕ' is controlled mainly by stereoelectronic and steric effects, whereas ψ' is controlled largely by sterics. The absence of an inter-residue hydrogen bond between atoms O3H and O5' in (I) does not significantly alter the linkage conformation relative to (II) and (III), in which this hydrogen bond is observed. In comparison, the internal glycosidic torsion angles in (IV) and (V) are -93.6 and -68.2 (3)° for ϕ', respectively, and -144.8 and -123.9 (2)° for ψ', respectively, despite internal glycosidic linkages identical to those found in (I)–(III) (i.e. β-Gal-(1→4) linkages to Glcp, Manp or Allp residues). It is noteworthy that ϕ' in (V) deviates significantly from the related torsion angles in (I)–(IV), whereas the ψ' values in (IV) and especially in (V) deviate considerably from the corresponding values observed in (I)–(III). Thus, within (I)–(V), the ϕ' values range from -68 to -96°, with four values clustered near -90°, whereas the ψ' values range from -124 to -161°, with three values clustered near -160°. While the structural difference at C2 in (IV) and (V) is more remote from the internal glycosidic linkage than that at C3 in (I) and (II), the effect on linkage conformation appears greater in the former.

The exocyclic hydroxymethyl conformation in (I)–(III) is similar, with ω averaging -57 (4)° and ω' averaging 57 (4)°. These values correspond to a gg conformation (H4 anti to O6) for ω and a gt conformation for ω' (C4' anti to O6').

Methyl β-lactoside, (II), crystallizes as a methanol solvate, whereas (I) crystallizes as a tetrahydrate. This difference exerts a major effect on the hydrogen-bonding networks displayed by both molecules in the crystalline state. Five of the 11 O atoms in (I) are not hydrogen-bonded in the crystal structure: O3, O5, O1', O4' and O5'. Of the remaining six O atoms, only two serve as mono-acceptors to other adjacent molecules of (I), namely O2' and O3'. The remaining four O atoms are hydrogen-bonded to water, with three (O1, O2 and O6) serving as mono-acceptors, and O6' serving as a double hydrogen-bond acceptor to water and an adjacent molecule of (I). All H atoms bonded to O atoms in (I) participate in hydrogen bonding, with H atoms on O6, O2' and O3' bonded to adjacent molecules of (I), and H atoms on O2, O3, O4' and O6' hydrogen-bonded to water. The four water molecules are fully hydrogen-bonded (i.e. each serves as a dual acceptor and donor) to other water molecules or to molecules of (I). The water molecules are all located within a channel bounded by molecules of (I) within the lattice. This channel runs through the lattice parallel to the a axis (Fig. 2). Thus, the solvent water molecules in (I) play a dominant role in the crystal packing arrangement by hydrogen-bonding extensively with themselves and with multiple molecules of (I).

In (II), by comparison with (I), all hydroxyl H atoms bonded to O atoms are involved in intermolecular hydrogen bonding as donors, except for atom O3 which participates in intramolecular hydrogen bonding to atom O5'. All O atoms in (II), including atom O3, serve as mono-acceptors, except for O1, O5, O1' and O4', which are not hydrogen-bonded in the crystal structure. The methanol hydroxyl H atom is hydrogen-bonded to atom O6 of one molecule of (II), while the methanol O atom serves as a mono-acceptor to the H atom on O4' of an adjacent molecule of (II).

Related literature

For related literature, see: Angyal et al. (1979); Bose et al. (1998); Cloran et al. (1999); Cremer & Pople (1975); Ham & Williams (1970); Hu et al. (2010); Pan et al. (2005); Stenutz et al. (1999); Zhao et al. (2008).

S2. Experimental

The crystal structure of (I) was determined using a ¹³C-labeled form of the molecule, which was prepared according to a nine-step synthesis described in the second scheme; full details are available in the archived CIF. The final purified product, obtained initially as a syrup after Dowex 50 × 8 (200–400 mesh) (Ca²⁺) chromatography (Angyal et al., 1979), was dissolved in a small amount of water, and the solution was allowed to evaporate slowly at room temperature. A small crystal of (I) was harvested for use in the structure determination.

S3. Refinement

Due to the small size and light-atom nature of the sample, synchrotron radiation was employed to perform the diffraction study. Despite several recrystallization attempts, it was not possible to obtain larger crystals. The instrumentation is outlined in the tables. The radiation wavelength was tuned using a channel-cut Si-<111> crystal monochromator. The instrumental set-up is identical to a laboratory source, differing only in orientation of the goniometer (vertical cf horizontal), due to the highly polarized X-ray source of the Advanced Light Source at Lawrence Berkeley National Laboratory. Data collection, reduction and structure solution and refinement (with appropriate neutral-atom scattering factors) are otherwise as would normally be undertaken in a standard X-ray facility.

Due to the use of intense synchrotron radiation, a number of reflections overloaded the detector, even with high-speed retakes or attenuation of the beam. The software assigns a zero intensity value for these reflections and it becomes immediately obvious in the F_o² versus F_c² analysis that they are misassigned. They were removed as disagreeable reflections during refinement.

H atoms bonded to C atoms were included in geometrically calculated positions, with C—H = 0.98–1.00 Å [Please check added text] and U_iso = 1.5U_eq(C) for methyl H and 1.2U_eq(C) for all others. Hydroxyl H atoms were initially included in their observed positions and subsequently constrained, allowing for re-orientation to optimize any potential hydrogen-bond interactions. H atoms on water molecules were all located from a difference Fourier map and initially included in those positions. They were subsequently refined with mild O—H bond-distance restraints [O—H = 0.84 (1) Å]. All H atoms bonded to O atoms were treated isotropically, with U_iso = 1.2U_eq(O).

Computing details

Data collection: APEX2 (Bruker Nonius, 2009); cell refinement: SAINT (Bruker Nonius, 2009); data reduction: SAINT (Bruker Nonius, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP (Sheldrick, 2008), POV-RAY (Cason, 2003) and DIAMOND (Brandenburg, 2009); software used to prepare material for publication: XCIF (Sheldrick, 2008), enCIFer (Allen et al., 2004) and publCIF (Westrip, 2010).

Figures

	Fig. 1. The chemical structure of (I). Displacement ellipsoids are depicted at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.
	Fig. 2. A packing diagram for (I), viewed along the a axis. Dashed lines indicate hydrogen bonds [Please check added text].

Methyl β-D-galactopyranosyl-(1→4)-β-D-allopyranoside tetrahydrate

Crystal data

C13H24O11·4H2O	F(000) = 920
Mr = 428.39	Dx = 1.437 Mg m^−3
Orthorhombic, P212121	Synchrotron radiation, λ = 0.77490 Å
Hall symbol: P 2ac 2ab	Cell parameters from 8643 reflections
a = 4.7071 (5) Å	θ = 2.4–33.2°
b = 20.125 (2) Å	µ = 0.12 mm^−1
c = 20.903 (2) Å	T = 150 K
V = 1980.1 (4) Å^3	Rod, colourless
Z = 4	0.10 × 0.04 × 0.04 mm

Data collection

Bruker APEXII diffractometer	5985 independent reflections
Radiation source: synchrotron	5510 reflections with I > 2σ(I)
Channel-cut Si-<111> crystal monochromator	Rint = 0.078
Detector resolution: 8.33 pixels mm^-1	θmax = 33.6°, θmin = 2.4°
combination of ω and ϕ–scans	h = −6→6
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 2008)	k = −28→28
Tmin = 0.988, Tmax = 0.995	l = −29→29
28515 measured reflections

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)] = 0.039	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.102	w = 1/[σ^2(Fo^2) + (0.0535P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.06	(Δ/σ)max = 0.001
5985 reflections	Δρmax = 0.36 e Å^−3
278 parameters	Δρmin = −0.20 e Å^−3
8 restraints	Absolute structure: Flack (1983), with 2548 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.1 (5)

Special details

Experimental. Synthesis of methyl β-D-[1-¹³C]galactopyranosyl-(1→4)-β-D-allopyranoside, (I) (Fig. 3).

Methyl 4,6-O-benzylidene-β-D-allopyranoside, (V). Methyl β-D-allopyranoside, (IV) (200 mg, 1.03 mmol), was dissolved in dry N,N-dimethylformamide (DMF) (15.0 ml), and benzaldehyde dimethylacetal (0.185 ml, 1.23 mmol) and a catalytic amount of p-toluenesulfonic acid were added. The reaction mixture was stirred at room temperature overnight and neutralized by adding one drop of triethylamine. The product was purified by flash chromatography on a silica-gel column (eluant: first, hexanes/ethyl acetate, 1:1; then methanol/ethyl acetate, 1:2), affording (V) (202 mg, 0.72 mmol, 70%).

Methyl 2,3-di-O-benzyl-4,6-O-benzylidene-α-D-allopyranoside, (VI). Compound (V) (150 mg, 0.53 mmol) was dissolved in DMF (15.0 ml) and NaH (90%, 150 mg, 5.62 mmol) was added to the solution. After stirring at room temperature for 1 h, benzyl bromide (0.37 ml, 3.12 mmol) was added dropwise at 273 K and the mixture was stirred at room temperature for 20 h. The mixture was then washed with distilled water and extracted with CH₂Cl₂. The organic phase was dried over Na₂SO₄, evaporated to dryness, and purified by flash chromatography on a silica-gel column (eluant: hexanes/ethyl acetate, 2:1) to afford (VI) (300 mg, 0.65 mmol, 90%).

Methyl 2,3,6-tri-O-benzyl-α-D-allopyranoside, (VII). Compound (VI) (300 mg, 0.65 mmol) and sodium cyanoborohydride (410 mg, 6.50 mmol) were dissolved in anhydrous tetrahydrofuran (THF) (10.0 ml) and molecular sieves (4 Å, 0.5 g) were added. Hydrogen chloride in diethyl ether (1M, 8.0 ml) was added dropwise and the mixture was stirred for 2 h (Dennison & McGilary, 1951). The mixture was diluted with CH₂Cl₂ and filtered, and the filtrate was washed with distilled water and saturated NaHCO₃ solution. The organic layer was evaporated to dryness and purified by flash chromatography on a silica-gel column (eluant: hexanes/ethyl acetate, 3:1) to afford (VII) (2.14 mg, 0.46 mmol, 71%).

2,3,4,6-Tetra-O-acetyl-α-D-[1-¹³C]galactopyranosyl trichloroacetimidate, (X). D-[1-¹³C]Galactose (300 mg, 1.66 mmol; Omicron Biochemicals, Inc., South Bend, Indiana, USA) was dissolved in pyridine (10 ml) and acetic anhydride (1.56 ml, 16.6 mmol) was added. The reaction mixture was stirred at room temperature overnight and concentrated in vacuo to afford the per-O-acetylated D-[1-¹³C]galactopyranose, (VIII). Compound (VIII) was deacetylated at C1 with benzylamine (0.22 ml, 2.01 mmol) in THF (20.0 ml) to afford the reducing sugar, (IX). After purification, (IX) was converted to the corresponding trichloroacetimidate with trichloroacetonitrile and 1,8-diazobicyclo[5.4.0]-undec-7-ene (DBU), as described previously (Schmidt & Michel, 1985), affording (X) (530 mg, 1.08 mmol, 65%).

Methyl 4-O-(2,3,4,6-tetra-O-acetyl-β-D-[1-¹³C]galactopyranosyl)- 2,3,6-tri-O-benzyl-β-D-allopyranoside, (XI). The donor, (X) (210 mg, 0.43 mmol), and acceptor, (VII) (150 mg, 0.33 mmol), were dissolved in anhydrous CH₂Cl₂ (20.0 ml) after drying over high vacuum, and the solution was treated with molecular sieves (4 Å). A catalytic amount of trimethylsilyltriflate (15 ml, 0.08 mmol) was added under N₂ at 233 K. After 2 h, the reaction mixture was quenched with the addition of triethylamine and the molecular sieves were removed by filtration. The solution was concentrated and purified by flash chromatography on a silica-gel column (eluant: hexanes/ethyl acetate, 2:1) to afford (XI) (166 mg, 0.21 mmol, 64%).

Methyl 4-O-β-D-[1-¹³C]galactopyranosyl-β-D-allopyranoside, (I). Compound (XI) (150 mg, 0.19 mmol) was dissolved in ethanol (10.0 ml) and treated with Pd/C (10%, 200 mg) and H₂ (1 psi) overnight. The Pd/C catalyst was removed by filtration and the filtrate was concentrated in vacuo. The residue was dissolved in methanol (10.0 ml) saturated with NH₃ (Ning et al., 2003). After 16 h, the reaction mixture was dried at 303 K in vacuo. The residue was dissolved in ~1 ml of water and the solution was applied to a column (2.5 × 100 cm) containing Dowex 50 × 8 (200–400 mesh) ion-exchange resin in the Ca²⁺ form (Angyal et al., 1979). The column was eluted with distilled decarbonated water at ~1.5 ml min^-1, and fractions (10 ml) were collected and assayed by TLC (silica gel; spots detected by charring after spraying with 1% (w/v) CeSO₄ – 2.5% (w/v) (NH₄)₆Mo₇O₂₄ – 10% aqueous H₂SO₄ reagent) (Tropper et al., 1992). Fractions 15–17 were pooled and concentrated at 303 K in vacuo to give (I) (60 mg, 0.17 mmol, 90%).

References: Angyal, S., Bethell, G. S. & Beveridge, R. (1979). Carbohydr. Res. 73, 9–18.

Dennison, J. C. & McGilary, O. I. (1951). J. Chem. Soc. p. 1616.

Ning, J., Zhang, W., Yi, Y., Yang, G., Wu, Z., Yi, J. & Kong, F. (2003). Bioorg. Med. Chem. 11, 2193–2203.

Schmidt, R. R. & Michel, J. (1985). J. Carbohydr. Chem. 4, 141–169.

Tropper, F. D., Andersson, F. O., Grand-Maitre, C. & Roy, R. (1992). Carbohydr. Res. 229, 149–154.

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	0.8199 (2)	0.62883 (5)	0.41438 (5)	0.0192 (2)
O2	0.8860 (2)	0.76695 (5)	0.41046 (5)	0.0201 (2)
H2	0.7198	0.7812	0.4156	0.024*
O3	0.5077 (2)	0.78337 (5)	0.30459 (5)	0.01786 (19)
H3	0.4819	0.8223	0.2913	0.021*
O5	0.7678 (2)	0.62311 (4)	0.30593 (4)	0.01622 (19)
O6	0.9929 (2)	0.58634 (5)	0.18504 (5)	0.0190 (2)
H6	1.0474	0.5605	0.2141	0.023*
C1	0.7245 (3)	0.66381 (6)	0.36095 (6)	0.0149 (2)
H1A	0.5184	0.6747	0.3657	0.018*
C2	0.8980 (3)	0.72747 (6)	0.35379 (6)	0.0149 (2)
H2A	1.1006	0.7145	0.3467	0.018*
C3	0.7968 (3)	0.76474 (6)	0.29437 (6)	0.0143 (2)
H3A	0.9158	0.8053	0.2877	0.017*
C4	0.8242 (3)	0.71823 (6)	0.23641 (6)	0.0133 (2)
H4A	1.0296	0.7077	0.2294	0.016*
C5	0.6622 (3)	0.65334 (6)	0.24812 (6)	0.0141 (2)
H5A	0.4555	0.6634	0.2534	0.017*
C6	0.6994 (3)	0.60287 (6)	0.19492 (6)	0.0172 (2)
H6A	0.5925	0.5620	0.2057	0.021*
H6B	0.6195	0.6211	0.1548	0.021*
C7	0.6246 (4)	0.57813 (7)	0.43372 (7)	0.0274 (3)
H7A	0.6969	0.5559	0.4721	0.041*
H7B	0.6037	0.5456	0.3992	0.041*
H7C	0.4395	0.5982	0.4431	0.041*
O1'	0.7102 (2)	0.74631 (4)	0.17910 (4)	0.01448 (18)
O2'	0.9576 (2)	0.72375 (4)	0.05712 (4)	0.01619 (19)
H2'	0.8226	0.6971	0.0516	0.019*
O3'	0.9697 (2)	0.84013 (5)	−0.02526 (4)	0.01607 (19)
H3'	0.8162	0.8209	−0.0341	0.019*
O4'	0.6250 (2)	0.92429 (5)	0.05401 (4)	0.01727 (19)
H4'	0.6125	0.9374	0.0160	0.021*
O5'	0.7894 (2)	0.85754 (4)	0.17013 (4)	0.01531 (19)
O6'	0.8955 (2)	0.97328 (5)	0.24055 (4)	0.0185 (2)
H6'	0.7496	0.9589	0.2591	0.022*
C1'	0.8844 (3)	0.79369 (6)	0.14953 (6)	0.0131 (2)
H1'A	1.0874	0.7867	0.1619	0.016*
C2'	0.8482 (3)	0.78660 (6)	0.07718 (6)	0.0130 (2)
H2'A	0.6416	0.7891	0.0663	0.016*
C3'	1.0056 (3)	0.84238 (6)	0.04297 (6)	0.0130 (2)
H3'A	1.2128	0.8369	0.0522	0.016*
C4'	0.9147 (3)	0.91032 (6)	0.06877 (6)	0.0139 (2)
H4'A	1.0384	0.9456	0.0498	0.017*
C5'	0.9519 (3)	0.91003 (6)	0.14162 (6)	0.0151 (2)
H5'A	1.1573	0.9035	0.1521	0.018*
C6'	0.8485 (3)	0.97408 (6)	0.17239 (6)	0.0179 (3)
H6'A	0.9504	1.0123	0.1533	0.021*
H6'B	0.6432	0.9798	0.1637	0.021*
O1W	0.4067 (3)	0.91936 (5)	0.28801 (5)	0.0225 (2)
H1WA	0.410 (5)	0.9294 (9)	0.3264 (5)	0.027*
H1WB	0.251 (3)	0.9344 (9)	0.2738 (9)	0.027*
O2W	0.3869 (3)	0.81824 (6)	0.45761 (5)	0.0232 (2)
H2WA	0.361 (5)	0.8191 (9)	0.4965 (5)	0.028*
H2WB	0.232 (3)	0.8040 (9)	0.4428 (9)	0.028*
O3W	0.9368 (3)	1.02163 (5)	0.43058 (5)	0.0229 (2)
H3WA	1.090 (3)	1.0005 (9)	0.4288 (9)	0.028*
H3WB	0.934 (5)	1.0450 (9)	0.3975 (6)	0.028*
O4W	0.4406 (3)	0.94879 (6)	0.41586 (5)	0.0253 (2)
H4WA	0.596 (3)	0.9679 (9)	0.4227 (9)	0.030*
H4WB	0.446 (5)	0.9095 (5)	0.4296 (9)	0.030*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0245 (5)	0.0190 (4)	0.0142 (4)	−0.0024 (4)	−0.0028 (4)	0.0049 (4)
O2	0.0206 (5)	0.0229 (5)	0.0168 (4)	0.0011 (4)	−0.0014 (4)	−0.0062 (4)
O3	0.0166 (4)	0.0148 (4)	0.0222 (4)	0.0048 (4)	0.0031 (4)	0.0011 (3)
O5	0.0232 (5)	0.0126 (4)	0.0128 (4)	0.0032 (4)	−0.0011 (4)	0.0009 (3)
O6	0.0237 (5)	0.0164 (4)	0.0169 (4)	0.0041 (4)	0.0023 (4)	0.0006 (3)
C1	0.0175 (6)	0.0145 (5)	0.0126 (5)	0.0006 (5)	0.0000 (5)	0.0022 (4)
C2	0.0144 (5)	0.0157 (5)	0.0146 (5)	−0.0006 (5)	−0.0004 (5)	−0.0010 (4)
C3	0.0148 (5)	0.0126 (5)	0.0153 (5)	−0.0011 (4)	0.0007 (5)	−0.0006 (4)
C4	0.0149 (6)	0.0121 (5)	0.0130 (5)	0.0014 (5)	−0.0006 (4)	0.0012 (4)
C5	0.0163 (6)	0.0129 (5)	0.0131 (5)	0.0006 (5)	−0.0014 (5)	0.0004 (4)
C6	0.0205 (6)	0.0137 (5)	0.0174 (6)	0.0000 (5)	−0.0022 (5)	−0.0010 (4)
C7	0.0375 (9)	0.0235 (7)	0.0212 (6)	−0.0089 (7)	−0.0022 (6)	0.0072 (5)
O1'	0.0157 (4)	0.0141 (4)	0.0137 (4)	−0.0020 (3)	−0.0019 (3)	0.0036 (3)
O2'	0.0170 (4)	0.0120 (4)	0.0196 (4)	0.0002 (3)	0.0003 (4)	−0.0040 (3)
O3'	0.0178 (5)	0.0195 (4)	0.0109 (4)	−0.0013 (4)	0.0006 (3)	−0.0009 (3)
O4'	0.0166 (4)	0.0200 (4)	0.0151 (4)	0.0042 (4)	−0.0007 (4)	0.0014 (3)
O5'	0.0208 (5)	0.0112 (4)	0.0140 (4)	−0.0003 (3)	0.0033 (4)	−0.0006 (3)
O6'	0.0232 (5)	0.0183 (4)	0.0141 (4)	−0.0025 (4)	−0.0006 (4)	−0.0038 (3)
C1'	0.0150 (6)	0.0113 (5)	0.0132 (5)	−0.0003 (4)	0.0005 (5)	0.0000 (4)
C2'	0.0141 (5)	0.0118 (5)	0.0131 (5)	0.0003 (4)	0.0007 (4)	−0.0015 (4)
C3'	0.0136 (5)	0.0143 (5)	0.0112 (5)	0.0003 (5)	−0.0003 (4)	−0.0007 (4)
C4'	0.0143 (6)	0.0129 (5)	0.0145 (5)	−0.0009 (4)	0.0002 (4)	−0.0006 (4)
C5'	0.0175 (6)	0.0133 (5)	0.0144 (5)	−0.0017 (5)	−0.0006 (5)	−0.0006 (4)
C6'	0.0244 (7)	0.0141 (5)	0.0152 (5)	0.0003 (5)	−0.0004 (5)	−0.0023 (4)
O1W	0.0248 (5)	0.0216 (5)	0.0210 (5)	0.0032 (4)	0.0015 (4)	0.0001 (4)
O2W	0.0239 (5)	0.0292 (5)	0.0166 (4)	−0.0018 (5)	0.0002 (4)	−0.0044 (4)
O3W	0.0258 (6)	0.0250 (5)	0.0180 (4)	0.0032 (4)	0.0030 (4)	0.0032 (4)
O4W	0.0257 (6)	0.0253 (5)	0.0248 (5)	−0.0004 (4)	0.0023 (5)	0.0018 (4)

Geometric parameters (Å, º)

O1—C1	1.3944 (15)	C2—H2A	1.0000
O1—C7	1.4315 (18)	C3—H3A	1.0000
O2—C2	1.4274 (15)	C4—H4A	1.0000
O3—C3	1.4274 (17)	C5—H5A	1.0000
O5—C1	1.4267 (15)	C6—H6A	0.9900
O5—C5	1.4412 (15)	C6—H6B	0.9900
O6—C6	1.4357 (18)	C7—H7A	0.9800
C1—C2	1.5264 (18)	C7—H7B	0.9800
C2—C3	1.5272 (18)	C7—H7C	0.9800
C3—C4	1.5365 (17)	O2'—H2'	0.8400
C4—O1'	1.4292 (15)	O3'—H3'	0.8400
C4—C5	1.5321 (17)	O4'—H4'	0.8400
C5—C6	1.5163 (18)	O6'—H6'	0.8400
O1'—C1'	1.4014 (15)	C1'—H1'A	1.0000
O2'—C2'	1.4286 (14)	C2'—H2'A	1.0000
O3'—C3'	1.4369 (14)	C3'—H3'A	1.0000
O4'—C4'	1.4265 (17)	C4'—H4'A	1.0000
O5'—C1'	1.4271 (15)	C5'—H5'A	1.0000
O5'—C5'	1.4339 (15)	C6'—H6'A	0.9900
O6'—C6'	1.4418 (16)	C6'—H6'B	0.9900
C1'—C2'	1.5286 (17)	O1W—H1WA	0.827 (9)
C2'—C3'	1.5234 (17)	O1W—H1WB	0.845 (9)
C3'—C4'	1.5309 (17)	O2W—H2WA	0.821 (9)
C4'—C5'	1.5327 (17)	O2W—H2WB	0.843 (10)
C5'—C6'	1.5205 (17)	O3W—H3WA	0.838 (10)
O2—H2	0.8400	O3W—H3WB	0.838 (9)
O3—H3	0.8400	O4W—H4WA	0.839 (10)
O6—H6	0.8400	O4W—H4WB	0.841 (9)
C1—H1A	1.0000
C1—O1—C7	112.30 (11)	C4—C3—H3A	109.9
C1—O5—C5	112.60 (9)	O1'—C4—H4A	108.9
O1—C1—O5	108.05 (10)	C5—C4—H4A	108.9
O1—C1—C2	109.28 (11)	C3—C4—H4A	108.9
O5—C1—C2	109.06 (10)	O5—C5—H5A	109.2
O2—C2—C1	111.39 (11)	C6—C5—H5A	109.2
O2—C2—C3	112.90 (10)	C4—C5—H5A	109.2
C1—C2—C3	108.98 (11)	O6—C6—H6A	109.2
O3—C3—C2	107.74 (11)	C5—C6—H6A	109.2
O3—C3—C4	110.98 (11)	O6—C6—H6B	109.2
C2—C3—C4	108.41 (10)	C5—C6—H6B	109.2
O1'—C4—C5	106.50 (10)	H6A—C6—H6B	107.9
O1'—C4—C3	112.87 (10)	O1—C7—H7A	109.5
C5—C4—C3	110.58 (10)	O1—C7—H7B	109.5
O5—C5—C6	107.00 (10)	H7A—C7—H7B	109.5
O5—C5—C4	108.79 (10)	O1—C7—H7C	109.5
C6—C5—C4	113.34 (11)	H7A—C7—H7C	109.5
O6—C6—C5	111.84 (11)	H7B—C7—H7C	109.5
C1'—O1'—C4	114.77 (10)	C2'—O2'—H2'	109.5
C1'—O5'—C5'	111.76 (10)	C3'—O3'—H3'	109.5
O1'—C1'—O5'	107.23 (10)	C4'—O4'—H4'	109.5
O1'—C1'—C2'	107.91 (10)	C6'—O6'—H6'	109.5
O5'—C1'—C2'	110.34 (10)	O1'—C1'—H1'A	110.4
O2'—C2'—C3'	109.83 (10)	O5'—C1'—H1'A	110.4
O2'—C2'—C1'	109.43 (10)	C2'—C1'—H1'A	110.4
C3'—C2'—C1'	109.96 (10)	O2'—C2'—H2'A	109.2
O3'—C3'—C2'	112.66 (10)	C3'—C2'—H2'A	109.2
O3'—C3'—C4'	110.18 (10)	C1'—C2'—H2'A	109.2
C2'—C3'—C4'	110.90 (10)	O3'—C3'—H3'A	107.6
O4'—C4'—C3'	111.53 (10)	C2'—C3'—H3'A	107.6
O4'—C4'—C5'	108.95 (10)	C4'—C3'—H3'A	107.6
C3'—C4'—C5'	108.34 (10)	O4'—C4'—H4'A	109.3
O5'—C5'—C6'	106.14 (10)	C3'—C4'—H4'A	109.3
O5'—C5'—C4'	110.78 (10)	C5'—C4'—H4'A	109.3
C6'—C5'—C4'	112.37 (11)	O5'—C5'—H5'A	109.2
O6'—C6'—C5'	111.07 (11)	C6'—C5'—H5'A	109.2
C2—O2—H2	109.5	C4'—C5'—H5'A	109.2
C3—O3—H3	109.5	O6'—C6'—H6'A	109.4
C6—O6—H6	109.5	C5'—C6'—H6'A	109.4
O1—C1—H1A	110.1	O6'—C6'—H6'B	109.4
O5—C1—H1A	110.1	C5'—C6'—H6'B	109.4
C2—C1—H1A	110.1	H6'A—C6'—H6'B	108.0
O2—C2—H2A	107.8	H1WA—O1W—H1WB	106 (2)
C1—C2—H2A	107.8	H2WA—O2W—H2WB	104 (2)
C3—C2—H2A	107.8	H3WA—O3W—H3WB	105.1 (19)
O3—C3—H3A	109.9	H4WA—O4W—H4WB	110 (2)
C2—C3—H3A	109.9
C7—O1—C1—O5	−76.36 (14)	C3—C4—O1'—C1'	77.55 (13)
C7—O1—C1—C2	165.10 (11)	C4—O1'—C1'—O5'	−96.40 (12)
C5—O5—C1—O1	176.94 (10)	C4—O1'—C1'—C2'	144.74 (10)
C5—O5—C1—C2	−64.37 (14)	C5'—O5'—C1'—O1'	−179.06 (10)
O1—C1—C2—O2	−56.01 (14)	C5'—O5'—C1'—C2'	−61.78 (14)
O5—C1—C2—O2	−173.93 (10)	O1'—C1'—C2'—O2'	−66.04 (13)
O1—C1—C2—C3	178.78 (10)	O5'—C1'—C2'—O2'	177.10 (10)
O5—C1—C2—C3	60.86 (14)	O1'—C1'—C2'—C3'	173.24 (10)
O2—C2—C3—O3	−60.91 (14)	O5'—C1'—C2'—C3'	56.38 (14)
C1—C2—C3—O3	63.41 (13)	O2'—C2'—C3'—O3'	62.01 (14)
O2—C2—C3—C4	178.91 (11)	C1'—C2'—C3'—O3'	−177.51 (10)
C1—C2—C3—C4	−56.77 (14)	O2'—C2'—C3'—C4'	−173.96 (10)
O3—C3—C4—O1'	56.44 (14)	C1'—C2'—C3'—C4'	−53.48 (14)
C2—C3—C4—O1'	174.58 (11)	O3'—C3'—C4'—O4'	59.15 (13)
O3—C3—C4—C5	−62.74 (13)	C2'—C3'—C4'—O4'	−66.29 (13)
C2—C3—C4—C5	55.40 (14)	O3'—C3'—C4'—C5'	179.06 (11)
C1—O5—C5—C6	−175.43 (11)	C2'—C3'—C4'—C5'	53.62 (14)
C1—O5—C5—C4	61.78 (13)	C1'—O5'—C5'—C6'	−174.60 (10)
O1'—C4—C5—O5	−179.55 (10)	C1'—O5'—C5'—C4'	63.16 (13)
C3—C4—C5—O5	−56.58 (13)	O4'—C4'—C5'—O5'	63.81 (13)
O1'—C4—C5—C6	61.57 (13)	C3'—C4'—C5'—O5'	−57.70 (14)
C3—C4—C5—C6	−175.47 (11)	O4'—C4'—C5'—C6'	−54.72 (14)
O5—C5—C6—O6	−61.92 (14)	C3'—C4'—C5'—C6'	−176.23 (11)
C4—C5—C6—O6	57.99 (14)	O5'—C5'—C6'—O6'	60.84 (14)
C5—C4—O1'—C1'	−160.93 (10)	C4'—C5'—C6'—O6'	−177.93 (11)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O2W	0.84	1.94	2.7489 (16)	160
O3—H3···O1W	0.84	1.99	2.7992 (15)	163
O6—H6···O6′^i	0.84	2.01	2.8057 (13)	157
O2′—H2′···O3′^ii	0.84	1.90	2.7149 (14)	162
O3′—H3′···O2′^ii	0.84	1.97	2.8117 (14)	179
O4′—H4′···O3W^iii	0.84	1.98	2.8152 (14)	173
O6′—H6′···O1W	0.84	1.90	2.7307 (16)	171
O1W—H1WA···O4W	0.83 (1)	1.92 (1)	2.7418 (16)	176 (2)
O1W—H1WB···O6′^iv	0.85 (1)	1.98 (1)	2.8198 (16)	178 (2)
O2W—H2WA···O1^v	0.82 (1)	2.15 (1)	2.8972 (15)	152 (2)
O2W—H2WB···O2^iv	0.84 (1)	1.91 (1)	2.7561 (16)	177 (2)
O3W—H3WA···O4W^vi	0.84 (1)	1.97 (1)	2.8046 (16)	174 (2)
O3W—H3WB···O6^vii	0.84 (1)	1.95 (1)	2.7652 (14)	166 (2)
O4W—H4WA···O3W	0.84 (1)	1.94 (1)	2.7748 (17)	172 (2)
O4W—H4WB···O2W	0.84 (1)	1.95 (1)	2.7800 (16)	170 (2)

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