Methyl 4-O-β-D-galactopyranosyl α-D-mannopyran­oside methanol 0.375-solvate

Methyl β-D-galactopyranosyl-(1→4)-α-D-mannopyran­oside methanol 0.375-solvate, C₁₃H₂₄O₁₁·0.375CH₃OH, (I), was crystallized from a methanol–ethanol solvent system in a glycosidic linkage conformation, with φ′ (O5_Gal—C1_Gal—O1_Gal—C4_Man) = −68.2 (3)° and ψ′ (C1_Gal—O1_Gal—C4_Man—C5_Man) = −123.9 (2)°, where the ring is defined by atoms O5/C1–C5 (monosaccharide numbering); C1 denotes the anomeric C atom and C6 the exocyclic hydroxy­methyl C atom in the βGalp and αManp residues, respectively. The linkage conformation in (I) differs from that in crystalline methyl α-lactoside [methyl β-D-galactopyranosyl-(1→4)-α-D-gluco­pyran­oside], (II) [Pan, Noll & Serianni (2005). Acta Cryst. C61, o674–o677], where φ′ is −93.6° and ψ′ is −144.8°. An inter­molecular hydrogen bond exists between O3_Man and O5_Gal in (I), similar to that between O3_Glc and O5_Gal in (II). The structures of (I) and (II) are also compared with those of their constituent residues, viz. methyl α-D-mannopyran­oside, methyl α-D-glucopyran­oside and methyl β-D-galactopyran­o­side, revealing significant differences in the Cremer–Pople puckering parameters, exocyclic hydroxy­methyl group conformations and inter­molecular hydrogen-bonding patterns.

S1. Comment

As a component of ongoing studies of the effects of primary structure and solvation on the conformations of biologically important oligosaccharides, the title disaccharide, methyl β-D-galactopyranosyl-(1→4)-α-D-mannopyranoside, (I), was prepared with ¹³C-enrichment at C1' and C4 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). The latter NMR parameters can be used to determine the preferred exocyclic C—O torsion angles, ϕ and ψ, comprising its internal glycosidic linkage. Compound (I) can be viewed as a derivative of methyl α-lactoside [methyl β-D-galactopyranosyl-(1→4)-α-D-glucopyranoside], (II), the crystal structure of which was reported recently (Pan et al., 2005). A comparison of the structures of (I) and (II) in the crystalline and solution states allows an appraisal of the effect of C2 configuration on the conformation of the internal glycosidic linkage.

Disaccharide (I) (Fig. 1) was crystallized from a methanol–ethanol solvent system. The crystal structure of (I) is compared with that of (II), and with those of their respective constituent residues, methyl α-D-mannopyranoside, (III) (Jeffrey et al., 1977), methyl α-D-glucopyranoside, (IV) (Jeffrey et al., 1977), and methyl β-D-galactopyranoside, (V) (Takagi & Jeffrey, 1979) (Table 1).

The endocyclic C—C bond lengths in (I)–(V) are similar [1.524 (6) Å for C1—C2 and 1.528 (7) Å for the remaining C—C bonds], showing that involvement of an anomeric C atom in an endocyclic C—C bond does not appreciably affect the length of the bond. In contrast, the average exocyclic C5—C6 bond length is 1.518 (3) Å, which is shorter than the average endocyclic C—C bond length.

The C—O bond lengths in (I)–(V) depend on structural context. Endocyclic C—O bonds (i.e. C1—O5 and C5—O5) are 1.428 (9) Å, and exocyclic C—O bonds are 1.421 (9) and 1.425 (9) Å for equatorial and axial bonds, respectively, that do not involve the anomeric C atom or other C atoms in a glycosidic linkage. The C1—O1 bond lengths are considerably shorter than other exo- and endocyclic C—O bonds and depend on bond orientation: axial 1.404 (5) Å and equatorial 1.389 (3) Å. The longer axial C1—O1 bond is presumably caused by n_O5→σ*_C1 donation (anomeric effect; Lemieux, 1971). The remaining unique C—O bond, C4—O1', is elongated [1.446 (1) Å] in (I) and (II); the formation of the glycosidic linkage apparently introduces steric constraints that are relieved partly through lengthening of the C—O bond.

The internal glycosidic C1'—O1'—C4 bond angles in (I) and (II) (115.5±0.3°) are very similar, and both values are larger than the terminal C1—O1—C7 angles in (I)–(V) (113.5±0.6°).

The endocyclic torsion angles in both residues of (I) and (II) vary widely and indicate slight distortions from ideal ⁴C₁ chair conformations. Cremer–Pople analysis (Cremer & Pople, 1975) showed relatively minor distortions in the αManp (θ = 3.9°) and αGlcp (θ = 3.3°) rings of (I) and (II), respectively (Table 2). Intermediate distortion is observed in the βGalp ring of (I) (θ = 6.5°), while the largest distortion is observed in the βGalp ring of (II) (θ = 11.5°). The direction of distortion is similar for the αManp and βGalp residues of (I) and (II) (ϕ = 78±5°), indicating a ⁴C₁ conformation slightly distorted towards B_1,4 (atoms O5/C1–C5 define the saccharide ring; C1 is the anomeric C atom, C5 the final C atom around the ring and C6 defined as the exocyclic hydroxymethyl C atom). The αGlcp residue of (II) (ϕ = 105°) is distorted towards ⁵S₁ (skew or twist-boat), while the βGalp residue of (I) (ϕ = 330°) is distorted towards ^OS₂. Less distortion is observed in (III)–(V) than in the corresponding residues of the disaccharides. The directions of distortion in (III) and (IV) mimic those observed in the corresponding residues in the disaccharides. In contrast, the βGalp ring in (V) resembles that in (I), but not that in (II). These results show that the βGalp ring can deform considerably in disaccharides, and that the type of deformation varies widely even when the residues to which it is attached are similar. In the present case, the difference may be caused by the considerably different internal glycosidic linkage conformations (see below) and/or different crystal packing forces.

The internal glycosidic torsion angles, ϕ' and ψ', in (I) differ considerably from the corresponding angles in (II) (Table 1). For ϕ' (O5'—C1'—O1'—C4), the difference is ~25°, with the conformation about the C1'—O1' bond in (I) being closer to an ideal staggered geometry. For ψ' (C1'—O1'—C4—C5) the difference is ~21°, with a nearly eclipsed conformation observed in (I). Interestingly, trans-glycoside J_CH and J_CC values (Bose et al., 1998) in (I) and (II) have been shown recently to be identical (Hu, Pan & Serianni, unpublished results), suggesting that, in aqueous solution, both structures are likely to have identical linkage conformations. Apparently crystal-packing forces in (I) stabilize the otherwise unfavorable linkage geometries expected from eclipsed interactions.

The exocyclic hydroxymethyl (CH₂OH) conformations in (I) and (II) differ significantly (Table 1). Torsion angles ω (O5—C5—C6—O6) in the αManp and αGlcp residues of (I) and (II) indicate gg and gt conformations, respectively. The tg conformation is found in the βGalp residue of (I), whereas gt is observed in the βGalp residue in (II). These observations are consistent with behavior found in solution by NMR, where a mix of gg and gt forms is commonly reported for αGlcp and αManp rings, and a gt/tg mix is reported for βGalp (Thibaudeau et al., 2004).

All hydroxyl H atoms in (I) are involved as donors in intermolecular hydrogen bonding in the crystal structure, except that of O3, which is involved in an intramolecular hydrogen bond with atom O5'. All O atoms in (I) are involved in hydrogen bonding as mono-acceptors, except O1, O2, O5 and O1'. Atoms O2', O3', O4', O6 and O6' are involved as mono-acceptors in intermolecular hydrogen bonding, and O5' serves as a mono-acceptor in an intramolecular hydrogen bond. In addition to serving as an intramolecular hydrogen-bond donor, atom O3 also serves as a mono-acceptor in an intermolecular hydrogen bond.

Like (I), all hydroxyl H atoms in (II) are involved in intermolecular hydrogen bonding as donors, except that of O3 which participates in intramolecular hydrogen bonding to atom O5'. All O atoms, including O3, serve as mono-acceptors, except for O1, O5, O1' and O4', which are not hydrogen-bonded in the crystal structure. This pattern is similar, but not identical, to that observed in (I). Differences occur at O2 and O4'. Atom O2 serves as a hydrogen-bond acceptor but O4' does not in (II), whereas the opposite is observed in (I). These findings suggest that intermolecular hydrogen bonding to axial O atoms as acceptors may be more structurally demanding than for equatorial O atoms in saccharide crystal formation.

The crystal packing of (I) is influenced by the symmetry imparted by the space group (I4), resulting in a ring of hydrogen-bonded molecules about the crystallographic c axis (Fig. 2, Table 3). Furthermore, there are hydrogen bonds between molecules parallel to the c axis. This bonding results in channels running through the lattice parallel to the c axis. These channels are populated with diffuse disordered solvent that cannot be reliably modeled. Examination of a Fourier difference map shows that the electron density within this channel extends for the entire length of the unit cell. The arrangement of the disaccharides about the channel is such that the methyl group (C7) and the βGalp CH₂OH functionality (C6') are oriented with their H atoms pointing towards the channel. Presumably this disposition renders the channel hydrophobic and this hydrophobicity may be the driving force for the presence of poorly located solvent molecule(s) within the channel. An analysis of the structure reveals a total of 390 Å^-3 of void space within the lattice. The electron count is 54 e^-. See Refinement section for further details.

S2. Experimental

The crystal structure of (I) was determined using a ¹³C-labeled form of the molecule, which was prepared according to the following seven-step procedure (see supplementary material).

Compound (XII) (0.64 g, 0.81 mmol) was dissolved in methanol (20 ml) and treated with a small amount of sodium methoxide (until the pH of the solution reached ~10) at room temperature for 3 h, and then neutralized with Dowex 50 × 8 (200–400 mesh) (H⁺) ion-exchange resin. The resulting solution was filtered, and the filtrate was evaporated to dryness. The residue was dissolved in ethanol (20 ml) and treated with Pd/C (0.22 g) and H₂ overnight to afford methyl 4-O-β-D-[1-¹³C]galactopyranosyl-α-D-[4-¹³C]mannopyranoside, (I). Purification by crystallization from a slowly cooled hot 2:1 methanol–ethanol solution gave (I) (0.25 g, 0.75 mmol, \sim 93%).

S3. Refinement

Hydroxyl group H atoms were located in a difference Fourier map, but were included in riding positions best defined to reduce the electron density at that location (O—H = 0.84 Å). All other H atoms were included in calculated positions (C—H = 0.98–1.00 Å). [Please check added H-atom distances] U_iso(H) = 1.5U_eq(C) for methyl H or 1.2U_eq(C,O) for all others.

The SQUEEZE routine from PLATON (Spek, 2009) was applied to the data to account for the solvent void within the lattice. Two void spaces with a total void volume of 390 Å^-3 and a sum of 54 e^- were accounted for within the unit cell. This could be accounted for by the inclusion of three molecules of methanol per unit cell. Thus, three molecules of methanol were included per unit cell (0.375 per formula unit) for the purposes of calculating µ, ρ, F(000) etc. Examination of the electron density within this pore shows an elongated tube of ill-defined density.

Computing details

Data collection: APEX2 (Bruker Nonius, 2008); cell refinement: APEX2 (Bruker Nonius, 2008) and SAINT (Bruker Nonius, 2008); data reduction: SAINT (Bruker Nonius, 2008) and XPREP (Sheldrick, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008), POV-RAY (Version 3.6.2; Cason, 2003) and DIAMOND (Version 3.2c; Brandenburg, 2009); software used to prepare material for publication: XCIF (Sheldrick, 2008), enCIFer (Allen et al., 2004) and publCIF (Westrip, 2009).

Figures

	Fig. 1. The molecular structure of (I), with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.
	Fig. 2. A space-filling diagram of (I), viewed down the c axis.

Methyl β-D-galactopyranosyl-(1→ 4)-α-D-mannopyranoside methanol 0.375-solvate

Crystal data

C13H24O11·0.375CH4O	Dx = 1.419 Mg m^−3
Mr = 368.34	Cu Kα radiation, λ = 1.54178 Å
Tetragonal, I4	Cell parameters from 6886 reflections
Hall symbol: I 4	θ = 4.4–69.0°
a = 20.1789 (4) Å	µ = 1.09 mm^−1
c = 8.4712 (2) Å	T = 100 K
V = 3449.37 (13) Å^3	Rod, colourless
Z = 8	0.25 × 0.05 × 0.05 mm
F(000) = 1574

Data collection

Bruker APEX diffractometer	2783 independent reflections
Radiation source: fine-focus sealed tube	2650 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.036
Detector resolution: 83.33 pixels mm^-1	θmax = 69.4°, θmin = 4.4°
ω and ϕ–scans	h = −24→23
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 2003)	k = −22→23
Tmin = 0.776, Tmax = 0.949	l = −9→10
12483 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)] = 0.044	H-atom parameters constrained
wR(F^2) = 0.104	w = 1/[σ^2(Fo^2) + (0.0467P)^2 + 5.8376P] where P = (Fo^2 + 2Fc^2)/3
S = 1.12	(Δ/σ)max = 0.003
2783 reflections	Δρmax = 0.44 e Å^−3
218 parameters	Δρmin = −0.26 e Å^−3
1 restraint	Absolute structure: Flack (1983), with how many Friedel pairs?
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.0 (2)

Special details

Experimental. The crystal structure of (I) was determined using a ¹³C-labeled form of the molecule, which was prepared according to the following seven-step procedure.

Methyl α-D-[4-¹³C]mannopyranoside, (VI), and methyl β-D-[4-¹³C]mannopyranoside, (VII), were prepared by refluxing D-[4-¹³C]mannose (0.80 g, 4.4 mmol; Omicron Biochemicals Inc., Indiana, USA) with dry Dowex 50 × 8 (200–400 mesh) (H⁺) resin in anhydrous methanol (55 ml). The resulting anomers were separated by crystallization, and the mother liquor was applied to a column containing Dowex 1 × 8 (200–400 mesh) (OH^-) ion-exchange resin (Austin et al., 1963), affording (VI) (0.74 g, 3.8 mmol, 86%) and (VII) (55 mg, 0.28 mmol, 6%).

Methyl 4,6-O-benzylidene-α-D-[4-¹³C]mannopyranoside, (VIII), was prepared as follows. Methyl α-D-[4-¹³C]mannopyranoside, (VI) (0.66 g, 3.4 mmol), was stirred at room temperature in dry N,N-dimethylformamide (DMF, 15 ml) containing benzaldehyde dimethylacetal (0.55 ml, 3.7 mmol) and a catalytic amount of p-toluenesulfonic acid for 2 d. The reaction mixture was neutralized by adding 3 drops of triethylamine. The mixture was evaporated to dryness and purified by flash chromatography on a silica-gel column, eluted first with hexanes–ethyl acetate (1:2 v/v) and then with methanol–ethyl acetate (1:2 v/v), affording (VIII) (0.75 g, 2.7 mmol, 78%).

Compound (VIII) (0.75 g, 2.7 mmol) was dissolved in DMF (25 ml), and NaH (60% dispersion, 1.1 g, 27.5 mmol) was added to the solution. The mixture was stirred at room temperature for 1 h. Benzyl bromide (2.11 ml, 17.8 mmol) was added dropwise at 273 K, and the mixture was stirred at 273 K for 1 h and then at room temperature for 15 h. The reaction mixture was quenched with the addition of a small amount of methanol. The mixture was washed with distilled water, filtered and the filtrate extracted with CH₂Cl₂. The organic phase was dried over Na₂SO₄, evaporated to dryness and purified by flash chromatography on a silica-gel column eluted with hexanes–ethyl acetate (2:1 v/v), to afford methyl 2,3-di-O-benzyl-4,6-O-benzylidene-α-D-[4-¹³C]mannopyranoside, (IX) (1.17 g, 2.53 mmol, 95%).

Compound (IX) (1.17 g, 2.53 mmol) and sodium cyanoborohydride (1.70 g, 27.0 mmol) were dissolved in anhydrous tetrahydrofuran (THF, 15 ml), and molecular sieves (4 Å, 1.3 g) were added. Hydrogen chloride in diethyl ether (1 M, 28 ml) was added dropwise and the mixture was stirred for 2.5 h. The mixture was diluted with CH₂Cl₂ and filtered, and the filtrate was extracted with distilled water and saturated NaHCO₃ solution. The organic layer was evaporated to dryness and purified by flash chromatography on a silica-gel column eluted with hexanes–ethyl acetate (4:1 v/v) to afford methyl 2,3,6-tri-O-benzyl-α-D-[4-¹³C]mannopyranoside, (X) (0.62 g, 1.3 mmol, 52%).

D-[1-¹³C]Galactose (1.95 g, 10.8 mmol; Omicron Biochemicals Inc., Indiana, USA) was dissolved in pyridine (25 ml) and treated with acetic anhydride (12 ml, 0.13 mol) at room temperature for 24 h. The solution was concentrated, diluted with CH₂Cl₂ and washed with distilled water. The organic phase was dried over anhydrous Na₂SO₄ and concentrated to afford the per-O-acetylated D-[1-¹³C]galactopyranose. The peracetate was deacetylated at C1 with benzylamine (1.4 ml, 12.8 mmol) in THF (55 ml) to afford the 1-OH compound, which was converted to the corresponding trichloroacetimidate with trichloroacetonitrile (10.59 ml, 0.11 mol) and 1,8-diazobicyclo[5.4.0]undec-7-ene (DBU), as described by Schmidt and coworkers (Schmidt, 1986; Yamazaki et al., 1990), affording 2,3,4,6-tetra-O-acetyl-α-D-[1-¹³C]galactopyranosyl trichloroacetimidate, (XI) (3.63 g, 7.4 mmol, ~68%).

Methyl 4-O-(2,3,4,6-tetra-O-acetyl-β-D-[1-¹³C]galactopyranosyl)-2,3,6-tri-O-benzyl-α-D-[4-¹³C]mannopyranoside, (XII), was prepared by coupling (XI) (1.06 g, 2.15 mmol) to (X) (0.62 g, 1.33 mmol) using the following standard method. The donor and acceptor were dissolved in anhydrous CH₂Cl₂ (30 µl) after drying in high vacuum, and the solution was treated with molecular sieves (4 Å). The solution was cooled to 233 K and treated with a small amount of trimethylsilyltriflate (30 ml, 0.16 mmol) under N₂. After 4 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 eluted with hexanes–ethyl acetate (3:1 v/v) to afford (XII) (0.64 g, 0.81 mmol, 61%).

Compound (XII) (0.64 g, 0.81 mmol) was dissolved in methanol (20 ml) and treated with a small amount of sodium methoxide (until the pH of the solution reached ~10) at room temperature for 3 h, and then neutralized with Dowex 50 × 8 (200–400 mesh) (H⁺) ion-exchange resin. The resulting solution was filtered, and the filtrate was evaporated to dryness. The residue was dissolved in ethanol (20 ml) and treated with Pd/C (0.22 g) and H₂ overnight to afford methyl 4-O-β-D-[1-¹³C]galactopyranosyl-α-D-[4-¹³C]mannopyranoside, (I). Purification by crystallization from a slowly cooled hot 2:1 methanol–ethanol solution gave (I) (0.25 g, 0.75 mmol, \sim 93%).

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.

H atoms on hydroxyls were located from a difference Fourier map, but were included in riding positions best defined to reduce the electron density at that location. All other H atoms were included in calculated positions. Thermal parameters for the H atoms were tied to those of the atoms to which they are bonded (1.5 X for methyl, 1.2 X for all others).

The SQUEEZE routine from PLATON (Spek, 2009) was applied to the data to account for the solvent void within the lattice. Two void spaces with a total void volume of 390 Å^-3 and a sum of 54 e^- were accounted for within the unit cell. This could be accounted for by the inclusion of three molecules of methanol per unit cell. Three molecules of methanol were included per unit cell (0.375 per formula unit) for purposes of calculation of µ, ρ F(000) etc. Examination of the electron density within this pore shows an elongated tube of ill-defined density.

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

	x	y	z	Uiso*/Ueq
C1	0.29044 (15)	0.32676 (15)	−0.2727 (4)	0.0224 (7)
H1A	0.3158	0.2954	−0.3412	0.027*
C2	0.22529 (14)	0.29477 (14)	−0.2249 (3)	0.0152 (6)
H2A	0.1982	0.2855	−0.3212	0.018*
C3	0.18755 (13)	0.34140 (14)	−0.1165 (4)	0.0173 (6)
H3A	0.1740	0.3817	−0.1771	0.021*
C4	0.23077 (13)	0.36199 (13)	0.0217 (3)	0.0140 (6)
H4A	0.2372	0.3236	0.0947	0.017*
C5	0.29804 (14)	0.38855 (14)	−0.0319 (3)	0.0155 (6)
H5A	0.2912	0.4316	−0.0882	0.019*
C6	0.34617 (14)	0.39946 (14)	0.1038 (4)	0.0174 (6)
H6A	0.3888	0.4158	0.0609	0.021*
H6B	0.3282	0.4341	0.1745	0.021*
C7	0.3281 (2)	0.4169 (2)	−0.4303 (4)	0.0403 (9)
H7A	0.3122	0.4493	−0.5075	0.060*
H7B	0.3570	0.3847	−0.4831	0.060*
H7C	0.3531	0.4397	−0.3473	0.060*
O1	0.27297 (12)	0.38322 (11)	−0.3619 (3)	0.0304 (6)
O2	0.23940 (10)	0.23441 (9)	−0.1456 (2)	0.0196 (5)
H2	0.2080	0.2077	−0.1595	0.024*
O3	0.12942 (10)	0.30787 (11)	−0.0597 (3)	0.0249 (5)
H3	0.1189	0.3232	0.0291	0.030*
O5	0.32899 (9)	0.34258 (10)	−0.1380 (2)	0.0191 (5)
O6	0.35807 (10)	0.34116 (9)	0.1932 (2)	0.0194 (4)
H6	0.3810	0.3146	0.1397	0.023*
C1'	0.17614 (13)	0.40078 (13)	0.2558 (3)	0.0131 (6)
H1'A	0.2142	0.3840	0.3200	0.016*
C2'	0.14944 (13)	0.46457 (13)	0.3253 (3)	0.0134 (6)
H2'A	0.1147	0.4828	0.2532	0.016*
C3'	0.11873 (14)	0.45227 (14)	0.4870 (3)	0.0137 (6)
H3'A	0.1545	0.4403	0.5634	0.016*
C4'	0.06914 (13)	0.39510 (13)	0.4769 (3)	0.0125 (6)
H4'A	0.0530	0.3837	0.5852	0.015*
C5'	0.10290 (13)	0.33431 (13)	0.4030 (3)	0.0130 (6)
H5'A	0.1425	0.3225	0.4681	0.016*
C6'	0.05834 (13)	0.27373 (13)	0.3899 (3)	0.0152 (6)
H6'A	0.0137	0.2875	0.3539	0.018*
H6'B	0.0768	0.2428	0.3106	0.018*
O1'	0.19650 (9)	0.41488 (9)	0.1026 (2)	0.0139 (4)
O2'	0.20373 (10)	0.50817 (10)	0.3280 (3)	0.0216 (5)
H2'	0.1917	0.5449	0.3645	0.026*
O3'	0.08741 (9)	0.51201 (9)	0.5379 (2)	0.0151 (4)
H3'	0.0909	0.5155	0.6363	0.018*
O4'	0.01374 (9)	0.41235 (9)	0.3784 (2)	0.0151 (4)
H4'	−0.0131	0.4356	0.4302	0.018*
O5'	0.12480 (9)	0.35215 (9)	0.2478 (2)	0.0127 (4)
O6'	0.05300 (9)	0.24089 (9)	0.5385 (2)	0.0179 (4)
H6'	0.0245	0.2602	0.5943	0.022*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0271 (16)	0.0300 (17)	0.0102 (15)	−0.0004 (13)	0.0008 (13)	−0.0058 (13)
C2	0.0177 (15)	0.0176 (14)	0.0104 (14)	0.0045 (11)	−0.0035 (11)	−0.0028 (11)
C3	0.0141 (14)	0.0192 (15)	0.0185 (16)	0.0047 (11)	−0.0038 (12)	−0.0018 (12)
C4	0.0164 (14)	0.0130 (14)	0.0127 (14)	0.0027 (10)	−0.0006 (11)	−0.0022 (11)
C5	0.0194 (15)	0.0154 (14)	0.0117 (14)	0.0009 (11)	0.0039 (11)	0.0003 (11)
C6	0.0172 (14)	0.0194 (15)	0.0157 (15)	−0.0005 (11)	0.0031 (12)	−0.0011 (12)
C7	0.050 (2)	0.048 (2)	0.022 (2)	−0.0118 (18)	0.0040 (16)	0.0047 (17)
O1	0.0445 (14)	0.0332 (13)	0.0135 (11)	−0.0088 (11)	−0.0018 (10)	0.0048 (9)
O2	0.0264 (11)	0.0148 (10)	0.0177 (11)	0.0019 (8)	−0.0018 (9)	−0.0020 (9)
O3	0.0154 (11)	0.0362 (13)	0.0231 (12)	−0.0011 (9)	0.0009 (9)	−0.0132 (9)
O5	0.0172 (10)	0.0273 (11)	0.0129 (11)	0.0013 (8)	0.0030 (8)	−0.0070 (9)
O6	0.0198 (10)	0.0232 (11)	0.0151 (10)	0.0037 (8)	−0.0014 (8)	−0.0011 (9)
C1'	0.0132 (13)	0.0151 (14)	0.0110 (15)	0.0011 (11)	0.0015 (11)	0.0014 (11)
C2'	0.0161 (14)	0.0111 (13)	0.0131 (15)	0.0009 (10)	0.0003 (11)	0.0023 (11)
C3'	0.0145 (13)	0.0156 (13)	0.0111 (14)	0.0042 (11)	−0.0005 (11)	−0.0002 (11)
C4'	0.0143 (14)	0.0143 (14)	0.0088 (13)	0.0038 (11)	−0.0013 (11)	0.0004 (11)
C5'	0.0144 (14)	0.0140 (14)	0.0106 (13)	0.0006 (11)	−0.0013 (11)	0.0009 (11)
C6'	0.0172 (14)	0.0137 (14)	0.0148 (15)	0.0018 (11)	−0.0024 (12)	0.0013 (11)
O1'	0.0184 (10)	0.0127 (9)	0.0105 (10)	0.0031 (8)	0.0043 (8)	0.0002 (8)
O2'	0.0257 (11)	0.0153 (10)	0.0237 (12)	−0.0035 (8)	0.0112 (9)	−0.0050 (9)
O3'	0.0212 (10)	0.0170 (10)	0.0071 (9)	0.0045 (7)	0.0005 (8)	−0.0025 (8)
O4'	0.0118 (9)	0.0194 (10)	0.0142 (11)	0.0056 (7)	0.0003 (8)	−0.0037 (8)
O5'	0.0131 (9)	0.0139 (10)	0.0112 (10)	−0.0016 (7)	0.0013 (8)	−0.0005 (8)
O6'	0.0194 (10)	0.0145 (10)	0.0199 (11)	0.0037 (8)	0.0077 (9)	0.0030 (8)

Geometric parameters (Å, º)

C1—O1	1.412 (4)	C1—H1A	1.0000
C1—O5	1.418 (4)	C2—H2A	1.0000
C1—C2	1.520 (4)	C3—H3A	1.0000
C2—O2	1.420 (3)	C4—H4A	1.0000
C2—C3	1.520 (4)	C5—H5A	1.0000
C3—O3	1.437 (4)	C6—H6A	0.9900
C3—C4	1.517 (4)	C6—H6B	0.9900
C4—O1'	1.445 (3)	C7—H7A	0.9800
C4—C5	1.528 (4)	C7—H7B	0.9800
C5—O5	1.434 (3)	C7—H7C	0.9800
C5—C6	1.521 (4)	O2—H2	0.8400
C6—O6	1.419 (4)	O3—H3	0.8400
C7—O1	1.427 (4)	O6—H6	0.8400
C1'—O1'	1.391 (3)	C1'—H1'A	1.0000
C1'—O5'	1.429 (3)	C2'—H2'A	1.0000
C1'—C2'	1.514 (4)	C3'—H3'A	1.0000
C2'—O2'	1.405 (3)	C4'—H4'A	1.0000
C2'—C3'	1.523 (4)	C5'—H5'A	1.0000
C3'—O3'	1.428 (3)	C6'—H6'A	0.9900
C3'—C4'	1.530 (4)	C6'—H6'B	0.9900
C4'—O4'	1.438 (3)	O2'—H2'	0.8400
C4'—C5'	1.537 (4)	O3'—H3'	0.8400
C5'—O5'	1.433 (3)	O4'—H4'	0.8400
C5'—C6'	1.521 (4)	O6'—H6'	0.8400
C6'—O6'	1.426 (3)
O1—C1—O5	112.7 (2)	O1'—C4—H4A	109.9
O1—C1—C2	105.6 (2)	C3—C4—H4A	109.9
O5—C1—C2	110.8 (2)	C5—C4—H4A	109.9
O2—C2—C3	110.2 (2)	O5—C5—H5A	108.9
O2—C2—C1	108.5 (2)	C6—C5—H5A	108.9
C3—C2—C1	109.4 (2)	C4—C5—H5A	108.9
O3—C3—C4	109.9 (2)	O6—C6—H6A	109.0
O3—C3—C2	108.7 (2)	C5—C6—H6A	109.0
C4—C3—C2	110.3 (2)	O6—C6—H6B	109.0
O1'—C4—C3	107.1 (2)	C5—C6—H6B	109.0
O1'—C4—C5	107.9 (2)	H6A—C6—H6B	107.8
C3—C4—C5	112.2 (2)	O1—C7—H7A	109.5
O5—C5—C6	106.8 (2)	O1—C7—H7B	109.5
O5—C5—C4	110.2 (2)	H7A—C7—H7B	109.5
C6—C5—C4	113.2 (2)	O1—C7—H7C	109.5
O6—C6—C5	113.0 (2)	H7A—C7—H7C	109.5
C1—O1—C7	114.0 (3)	H7B—C7—H7C	109.5
O1'—C1'—O5'	108.1 (2)	C2—O2—H2	109.5
O1'—C1'—C2'	107.1 (2)	C3—O3—H3	109.5
O5'—C1'—C2'	110.1 (2)	C6—O6—H6	109.5
O2'—C2'—C1'	105.1 (2)	O1'—C1'—H1'A	110.5
O2'—C2'—C3'	113.9 (2)	O5'—C1'—H1'A	110.5
C1'—C2'—C3'	110.8 (2)	C2'—C1'—H1'A	110.5
O3'—C3'—C2'	108.3 (2)	O2'—C2'—H2'A	108.9
O3'—C3'—C4'	111.4 (2)	C1'—C2'—H2'A	108.9
C2'—C3'—C4'	109.8 (2)	C3'—C2'—H2'A	108.9
O4'—C4'—C3'	111.0 (2)	O3'—C3'—H3'A	109.1
O4'—C4'—C5'	107.5 (2)	C2'—C3'—H3'A	109.1
C3'—C4'—C5'	109.6 (2)	C4'—C3'—H3'A	109.1
O5'—C5'—C6'	108.5 (2)	O4'—C4'—H4'A	109.6
O5'—C5'—C4'	108.1 (2)	C3'—C4'—H4'A	109.6
C6'—C5'—C4'	114.1 (2)	C5'—C4'—H4'A	109.6
C1—O5—C5	114.3 (2)	O5'—C5'—H5'A	108.7
O6'—C6'—C5'	110.7 (2)	C6'—C5'—H5'A	108.7
C1'—O1'—C4	115.7 (2)	C4'—C5'—H5'A	108.7
C1'—O5'—C5'	110.6 (2)	O6'—C6'—H6'A	109.5
O1—C1—H1A	109.2	C5'—C6'—H6'A	109.5
O5—C1—H1A	109.2	O6'—C6'—H6'B	109.5
C2—C1—H1A	109.2	C5'—C6'—H6'B	109.5
O2—C2—H2A	109.6	H6'A—C6'—H6'B	108.1
C3—C2—H2A	109.6	C2'—O2'—H2'	109.5
C1—C2—H2A	109.6	C3'—O3'—H3'	109.5
O3—C3—H3A	109.3	C4'—O4'—H4'	109.5
C4—C3—H3A	109.3	C6'—O6'—H6'	109.5
C2—C3—H3A	109.3
O1—C1—C2—O2	175.2 (2)	O5'—C1'—C2'—O2'	179.8 (2)
O5—C1—C2—O2	−62.4 (3)	O1'—C1'—C2'—C3'	173.6 (2)
O1—C1—C2—C3	−64.5 (3)	O5'—C1'—C2'—C3'	56.3 (3)
O5—C1—C2—C3	57.9 (3)	O2'—C2'—C3'—O3'	68.7 (3)
O2—C2—C3—O3	−55.1 (3)	C1'—C2'—C3'—O3'	−173.0 (2)
C1—C2—C3—O3	−174.2 (2)	O2'—C2'—C3'—C4'	−169.5 (2)
O2—C2—C3—C4	65.4 (3)	C1'—C2'—C3'—C4'	−51.2 (3)
C1—C2—C3—C4	−53.7 (3)	O3'—C3'—C4'—O4'	54.6 (3)
O3—C3—C4—O1'	−70.4 (3)	C2'—C3'—C4'—O4'	−65.4 (3)
C2—C3—C4—O1'	169.8 (2)	O3'—C3'—C4'—C5'	173.2 (2)
O3—C3—C4—C5	171.4 (2)	C2'—C3'—C4'—C5'	53.3 (3)
C2—C3—C4—C5	51.7 (3)	O4'—C4'—C5'—O5'	60.5 (3)
O1'—C4—C5—O5	−169.2 (2)	C3'—C4'—C5'—O5'	−60.3 (3)
C3—C4—C5—O5	−51.6 (3)	O4'—C4'—C5'—C6'	−60.3 (3)
O1'—C4—C5—C6	71.3 (3)	C3'—C4'—C5'—C6'	178.9 (2)
C3—C4—C5—C6	−171.1 (2)	O5'—C5'—C6'—O6'	160.7 (2)
O5—C5—C6—O6	−63.8 (3)	C4'—C5'—C6'—O6'	−78.7 (3)
C4—C5—C6—O6	57.7 (3)	O5'—C1'—O1'—C4	−68.2 (3)
O5—C1—O1—C7	64.3 (3)	C2'—C1'—O1'—C4	173.1 (2)
C2—C1—O1—C7	−174.5 (2)	C3—C4—O1'—C1'	115.2 (2)
O1—C1—O5—C5	57.3 (3)	C5—C4—O1'—C1'	−123.9 (2)
C2—C1—O5—C5	−60.9 (3)	O1'—C1'—O5'—C5'	178.53 (19)
C6—C5—O5—C1	−180.0 (2)	C2'—C1'—O5'—C5'	−64.8 (3)
C4—C5—O5—C1	56.7 (3)	C6'—C5'—O5'—C1'	−169.3 (2)
O1'—C1'—C2'—O2'	−62.9 (3)	C4'—C5'—O5'—C1'	66.4 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O6^i	0.84	2.08	2.839 (3)	151
O3—H3···O5′	0.84	1.95	2.755 (3)	161
O6—H6···O6′^i	0.84	1.94	2.771 (3)	170
O2′—H2′···O3^ii	0.84	1.82	2.636 (3)	163
O3′—H3′···O4′^ii	0.84	2.05	2.885 (3)	171
O4′—H4′···O3′^iii	0.84	2.05	2.884 (3)	173
O6′—H6′···O2′^iv	0.84	2.14	2.843 (3)	142
O6′—H6′···O1′^iv	0.84	2.38	3.108 (3)	145

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