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Journal logoSTRUCTURAL
CHEMISTRY
ISSN: 2053-2296

1,2,3,4-Tetra-O-acetyl-β-D-gluco­pyran­uronic acid monohydrate at 120 K and anhydrous 1,2,3,4-tetra-O-acetyl-β-D-gluco­pyranose at 292 K

CROSSMARK_Color_square_no_text.svg

aDepartment of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland, and bDepartamento de Química Inorgânica, Instituto de Química, Universidade Federal do Rio de Janeiro, CP 68563, 21945-970 Rio de Janeiro, RJ, Brazil
*Correspondence e-mail: r.a.howie@abdn.ac.uk

(Received 7 September 2005; accepted 26 October 2005; online 19 November 2005)

The structure of the title acid as the monohydrate, C14H18O11·H2O, displays hydrogen bonding which connects the mol­ecules in layers parallel to (10[\overline{1}]). In the anhydrous glucopyran­ose, C14H20O10, only chain connectivity is attained but, due to disorder of the OH group, only partially and in two modes, one less favoured than the other. This provides incomplete connectivity between mol­ecules in corrugated layers parallel to (010).

Comment

The title compounds, namely the acid monohydrate, (I)[link], previously reported by Fry (1955[Fry, E. M. (1955). J. Am. Chem. Soc. 77, 3915-3916.]), and the anhydrous glucopyran­ose, (II)[link], were prepared for use in esterifications with disaccharides.

[Scheme 1]

The asymmetric unit of (I)[link] and the mol­ecule of (II)[link] are shown in Figs. 1[link] and 2[link], respectively. The atom labelling is similar and differs only for the O atoms with numeric values of 7 or greater. The compounds obviously differ in terms of the substituents attached to C5, namely CO2H in (I)[link] and CH2OH in (II)[link], and in the fact that (II)[link] is anhydrous but (I)[link] is the monohydrate. The values given in Table 1[link] show that the carboxylic acid group in (I)[link] has the expected planar geometry, and bond lengths and angles are in the normal ranges. The hydroxyl group in (II)[link], however, is disordered over two sites, O6A and O6B, with occupancies of 0.639 (7) and 0.361 (7), respectively. The torsion angles given in Table 1[link] show that these sites are related to one another by rotation of the OH group about the C5—C6 bond by 145.1 (5)°. The C6—O6A and C6—O6B bond lengths of 1.396 (6) and 1.338 (8) Å, respectively, are disappointingly disparate, but this is regarded as a side effect of the disorder. The disorder of the OH group has, as will be discussed later, a profound effect upon the hydrogen bonding in (II)[link].

The pyran­ose rings, defined by atoms O5/C1–C5, are very similar in the two structures, with bond lengths and angles in the expected ranges and similar chair conformations with puckering parameters (Cremer & Pople, 1975[Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354-1358.]) [values for (II)[link] in square brackets] of 0.594 (2) Å [0.595 (2) Å], 8.4 (2)° [2.9 (2)°] and 349.1 (15)° [323 (6)°] for Q, θ and φ, respectively. The only significant differences between them reside in the torsion angles given in Table 2[link]. These reflect differences in the orientation of the acetyl substituents with respect to the pyran­ose rings. The difference is greatest for the acetyl groups in the 2-position, less at the 3-position, still less at position 4 and least of all at position 1.

The two structures also differ significantly in their hydrogen bonding. In (I)[link], the hydrogen bonds given in Table 3[link] inter­connect the mol­ecules to form layers, as shown in Fig. 3[link], parallel to (10[\overline{1}]), within which the recurring motif is the trimolecular ring, of which two examples appear in Fig. 3[link]. This connectivity comes about because the water mol­ecule operates as both donor (twice) and acceptor.

In (II)[link], with no water mol­ecule, the possibilities for hydrogen-bond formation (Table 4[link]) are reduced. They are, however, much influenced by the disorder of the OH group. The major component of the disorder, O6A—H6A, provides connectivity within chains propagated in the direction of (001) (Fig. 4[link]), in which the mol­ecules are connected edge-to-edge (type 1 chains). In contrast, the minor component, O6B—H6B, provides connectivity in chains of face-to-face mol­ecules propagated in the direction of (100) (type 2 chains; Fig. 5[link]). Because of the relative occupancies of the two sites, the type 1 chains are considered to be the dominant feature. Therefore, the type 2 connectivity is perceived as inter­connecting and, at the same time, fragmenting the type 1 chains. The combination of these two types of connection provides incomplete two-dimensional connectivity between mol­ecules which, as can be deduced from Figs. 4[link] and 5[link], are confined to corrugated layers parallel to (010), one unit cell thick and related to one another by cell translation. If every mol­ecule acts as acceptor for one, and only one, hydrogen bond, this has an intriguing, if conjectural, side effect upon the manner in which the type 2 inter­actions might be introduced into the structure of (II)[link]. The introduction of an isolated type 2 hydrogen bond, as in Fig. 6[link](b), leaves an acceptor, A1, unused, while A2 becomes a dual acceptor. The introduction of a second complementary and adjacent type 2 inter­action, as in Fig. 6[link](c), permits single-acceptor functionality for all mol­ecules.

The descriptions just given consider only the strong O—H⋯O hydrogen bonds given in Tables 3[link] and 4[link]. Weaker secondary O—H⋯O hydrogen bonds involving the H atoms of the water mol­ecule are also present in (I)[link] and still weaker C—H⋯O inter­actions are present in both structures. Many of these weaker inter­molecular inter­actions simply parallel or reinforce some of the primary hydrogen bonds.

[Figure 1]
Figure 1
The asymmetric unit of (I)[link]. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii. The dashed line represents an O—H⋯O hydrogen bond.
[Figure 2]
Figure 2
The mol­ecule of (II)[link], with displacement ellipsoids drawn at the 20% probability level and H atoms shown as small spheres of arbitrary radii. Only the major component of the twofold disorder of the OH group is shown.
[Figure 3]
Figure 3
A hydrogen-bonded layer of mol­ecules in (I)[link]. Displacement ellipsoids are drawn at the 20% probability level and H atoms involved in hydrogen bonds (dashed lines) are shown as small spheres of arbitrary radii. Selected atoms are labelled. [Symmetry codes: (i) 2 − x, y − [{1\over 2}], 2 − z; (ii) 1 − x, [{1\over 2}] + y, 1 − z; (iii) x − 1, y, z − 1; (iv) 1 − x, y − [{1\over 2}], 1 − z; (v) x, y − 1, z.]
[Figure 4]
Figure 4
A type 1 chain (see Comment) in (II)[link]. Displacement ellipsoids are drawn at the 10% probability level and H atoms involved in hydrogen bonds (dashed lines) are shown as small spheres of arbitrary radii. Selected atoms are labelled. [Symmetry codes: (i) [{3\over 2}] − x, 1 − y, z − [{1\over 2}]; (iv) [{3\over 2}] − x, 1 − y, z + [{1\over 2}].]
[Figure 5]
Figure 5
A type 2 chain (see Comment) in (II)[link]. Displacement ellipsoids are drawn at the 10% probability level and H atoms involved in hydrogen bonds (dashed lines) are shown as small spheres of arbitrary radii. Selected atoms are labelled. [Symmetry codes: (ii) x + [{1\over 2}], [{3\over 2}] − y, 1 − z; (v) x − [{1\over 2}], [{3\over 2}] − y, 1 − z.]
[Figure 6]
Figure 6
Schematic representation of types 1 and 2 hydrogen bonding in (II)[link]. Mol­ecules are represented by donor (D) and acceptor (A) centres joined by solid lines and hydrogen bonds by dashed lines. The arrangements shown are (a) a pair of type 1 chains; (b) as (a), but with the introduction of a single type 2 hydrogen bond, D1⋯A2; (c) as (b), but with the introduction of a second, complementary, type 2 hydrogen bond, D2⋯A1.

Experimental

For the preparation of compound (I)[link], glucuronic acid (5.00 g, 26 mmol) was added to a stirred solution of acetic anhydride (25 ml, 245 mmol) and concentrated sulfuric acid (3 drops). The temperature was allowed to reach 323 K and extra glucuronic acid (5.00 g, 26 mmol) was added. The reaction mixture was maintained at 323–333 K for 1 h with stirring and then cooled to room temperature. Water (75 ml) was added to the stirred solution. After 20 min, crystals of the monohydrate, (I)[link], which had separated out of the solution, were collected and washed with water (yield: 9.76 g, 49.8%); m.p. 369–372 K; [α]D24 (c = 3, CHCl3) 18.5; literature values for material recrystallized from toluene: m.p. 425–427 K; [α]D (CHCl3) 16.3 (Fry, 1955[Fry, E. M. (1955). J. Am. Chem. Soc. 77, 3915-3916.]). 1H NMR (250 MHz, CDCl3): δ 1.99 (s, 3H, Me), 2.01 (s, 3H, Me), 2.03 (s, 3H, Me), 2.07 (s, 3H, Me), 4.62 (d, 1H, J = 9.16 Hz, H6), 5.11 (dd, 1H, J = 6.8 and 8.5 Hz, H2), 5.25 (t, 1H, J = 8.5 Hz, H3), 5.41 (t, 1H, J = 8.5 Hz, H4), 5.83 (d, 1H, J = 6.8 Hz, H1); 13C NMR (63 MHz, CDCl3): δ 20.5, 20.8, 68.9, 70.2, 72.0, 73.1, 97.4, 166.4, 168.8, 169.2, 169.3, 169.9; IR (KBr, ν, cm−1): 3608–3401, 1761, 1747, 1618. MS (ES+): 385.2 [100%, M + Na], 401.1 [8%, M + K]. The monohydrate, (I)[link], used in the X-ray determination was recrystallized from an acetone–water (1:1 v/v) solution.

Compound (II)[link] was prepared in two stages. Firstly, simulaneous acetyl­ation at positions 1–4 and protection of O6 with a trityl group was carried out on commercially available β-D-glucose in the manner described by Talley (1963[Talley, E. A. (1963). Methods in Carbohydrate Chemistry II, edited by R. L. Whistler & M. L. Wolfrom, Section [88], pp. 337-340. New York: Academic Press.]) with procedural details as follows. To a hot solution of anhydrous D-glucose (20.0 g, 110 mmol) and trityl chloride (33.5 g, 120 mmol) in pyridine (100 ml) was added acetic anhydride (50 ml, 490 mmol). After stirring for 24 h, the reaction mixture was evaporated at reduced pressure to give a syrup. The syrup was added to water, stirred and the resulting precipitate filtered and washed with water. The precipitate was dried and yielded 25.8 g (39%) of the precursor of (II)[link] (m.p. 438–439 K). Thereafter, Amberlite IR 20 resin (20 g) and water (1 ml) were added to a solution of the precursor (20 g, 37 mmol) in CH3CN (100 ml). The stirred solution was heated at 333 K for 20 h. The reaction mixture was hot-filtered to remove the resin and, on cooling, a white precipitate formed from the reaction mixture. The precipitate was filtered off, washed with CH3CN, and the filtrate and washings combined. The solvent was removed at reduced pressure. A solution of the resulting solid in CH2Cl2 was dried by the addition of anhydrous CaCl2, which was then removed by filtration; the solvent was removed from the filtrate under reduced pressure. The solid (II)[link] obtained was crystallized initially from methyl tert-butyl ether. Further recrystallization from diethyl ether yielded (II)[link] in its final form (yield: 4.1 g, 37%); m.p. 403–404 K; [α]D (c = 4, CHCl3) 11.63; literature value: [α]D (CHCl3) 12 (Ding et al., 1997[Ding, X., Wang, W. & Kong, F. (1997). Carbohydr. Res. 303, 445-448.]; Horrobin et al., 1998[Horrobin, T., Tran, C. H. & Crout, D. (1998). J. Chem. Soc. Perkin Trans. 1, pp. 1069-1080.]). 1H NMR (500 MHz, CDCl3): δ 1.99 (s, 3H, Me), 2.00 (s, 3H, Me), 2.03 (s, 3H, Me), 2.08 (s, 3H, Me), 3.55 (dd, 1H, J = 4.2 and 12.5 Hz, H6), 3.62 (ddd, 1H, J = 2.3, 4.2 and 9.7 Hz, H5), 3.73 (dd, 1H, J = 2.3 and 12.5 Hz, H6), 5.07 (dd and t, 2H, J = 8.4 and 9.7 Hz, H2, 4), 5.27 (t, 1H, J = 9.7 Hz, H3), 5.70 (d, 1H, J = 8.4 Hz, H1); 13C NMR (63 MHz, CDCl3): δ, 20.6, 20.8, 60.8, 68.2, 70.4, 72.6, 77.6, 91.7, 169.1, 169.3, 170.1, 170.3; IR (KBr, ν, cm−1): 3540, 2954, 1749. MS (ES+): 371.2 [100%, M + Na], 387.1 [25%, M + K].

Table 1
Selected geometric parameters for (I)[link] and (II)[link] (Å, °)

  (I)[link]   (II)[link]
C6—O6 1.313 (3) C6—O6A 1.396 (6)
C6—O7 1.206 (3) C6—O6B 1.338 (8)
       
C5—C6—O6 110.1 (2) C5—C6—O6A 113.1 (4)
C5—C6—O7 123.0 (2) C5—C6—O6B 116.0 (4)
O6—C6—O7 126.9 (2)    
       
O5—C5—C6—O6 162.00 (19) O5—C5—C6—O6A 67.6 (3)
O5—C5—C6—O7 −17.8 (3) O5—C5—C6—O6B −77.5 (6)
C4—C5—C6—O6 −80.3 (3) C4—C5—C6—O6A −174.5 (3)
C4—C5—C6—O7 99.8 (3) C4—C5—C6—O6B 40.4 (6)

Table 2
Selected torsion angles (°) for (I)[link] and (II)[link]

  (I)[link] (II)[link]
C7—O1—C1—O5 −90.4 (2) −89.9 (3)
C7—O1—C1—C2 152.7 (2) 153.7 (2)
C9—O2—C2—C3 −93.0 (2) −119.2 (2)
C9—O2—C2—C1 148.7 (2) 121.4 (2)
C11—O3—C3—C2 −94.6 (3) −122.0 (2)
C11—O3—C3—C4 145.0 (2) 119.0 (3)
C13—O4—C4—C3 133.2 (2) 112.7 (2)
C13—O4—C4—C5 −107.2 (2) −127.4 (2)

Compound (I)[link]

Crystal data
  • C14H18O11·H2O

  • Mr = 380.30

  • Monoclinic, P 21

  • a = 9.0644 (4) Å

  • b = 10.4661 (6) Å

  • c = 9.7703 (5) Å

  • β = 103.131 (3)°

  • V = 902.66 (8) Å3

  • Z = 2

  • Dx = 1.399 Mg m−3

  • Mo Kα radiation

  • Cell parameters from 20602 reflections

  • θ = 2.9–27.5°

  • μ = 0.13 mm−1

  • T = 120 (2) K

  • Block, colourless

  • 0.26 × 0.24 × 0.12 mm

Data collection
  • Nonius KappaCCD area-detector diffractometer

  • φ and ω scans

  • Absorption correction: multi-scan(SORTAV; Blessing, 1995[Blessing, R. H. (1995). Acta Cryst. A51, 33-37.], 1997[Blessing, R. H. (1997). J. Appl. Cryst. 30, 421-426.])Tmin = 0.842, Tmax = 0.988

  • 6414 measured reflections

  • 2131 independent reflections

  • 1848 reflections with I > 2σ(I)

  • Rint = 0.047

  • θmax = 27.5°

  • h = −11 → 11

  • k = −12 → 13

  • l = −12 → 12

Refinement
  • Refinement on F2

  • R[F2 > 2σ(F2)] = 0.038

  • wR(F2) = 0.094

  • S = 1.09

  • 2131 reflections

  • 248 parameters

  • H atoms: see below

  • w = 1/[σ2(Fo2) + (0.0535P)2 + 0.0412P] where P = (Fo2 + 2Fc2)/3

  • (Δ/σ)max < 0.001

  • Δρmax = 0.26 e Å−3

  • Δρmin = −0.24 e Å−3

Table 3
Hydrogen-bond geometry (Å, °) for (I)[link]

D—H⋯A D—H H⋯A DA D—H⋯A
O6—H6⋯O1Wi 0.84 1.79 2.592 (3) 159
O1W—H1W1⋯O5 0.91 (5) 2.12 (5) 2.970 (3) 155 (4)
O1W—H1W2⋯O10ii 0.84 (5) 2.27 (5) 3.003 (3) 146 (4)
Symmetry codes: (i) [-x+2, y-{\script{1\over 2}}, -z+2]; (ii) [-x+1, y+{\script{1\over 2}}, -z+1].

Compound (II)[link]

Crystal data
  • C14H20O10

  • Mr = 348.30

  • Orthorhombic, P 21 21 21

  • a = 9.4830 (8) Å

  • b = 12.6536 (12) Å

  • c = 15.1455 (14) Å

  • V = 1817.4 (3) Å3

  • Z = 4

  • Dx = 1.273 Mg m−3

  • Mo Kα radiation

  • Cell parameters from 4864 reflections

  • θ = 2.7–24.3°

  • μ = 0.11 mm−1

  • T = 292 (2) K

  • Block, colourless

  • 0.50 × 0.50 × 0.27 mm

Data collection
  • Bruker SMART 1000 CCD area detector diffractometer

  • φ and ω scans

  • Absorption correction: multi-scan(SADABS; Sheldrick, 1999[Sheldrick, G. M. (1999). SADABS. Version 2.03. Bruker AXS Inc., Madison, Wisconsin, USA.])Tmin = 0.876, Tmax = 0.928

  • 21264 measured reflections

  • 3702 independent reflections

  • 1921 reflections with I > 2σ(I)

  • Rint = 0.040

  • θmax = 32.6°

  • h = −14 → 10

  • k = −18 → 19

  • l = −22 → 22

Refinement
  • Refinement on F2

  • R[F2 > 2σ(F2)] = 0.046

  • wR(F2) = 0.148

  • S = 1.00

  • 3702 reflections

  • 233 parameters

  • H-atom parameters constrained

  • w = 1/[σ2(Fo2) + (0.0739P)2 + 0.0408P] where P = (Fo2 + 2Fc2)/3

  • (Δ/σ)max < 0.001

  • Δρmax = 0.17 e Å−3

  • Δρmin = −0.17 e Å−3

Table 4
Hydrogen-bond geometry (Å, °) for (II)[link]

D—H⋯A D—H H⋯A DA D—H⋯A
O6A—H6A⋯O8i 0.82 2.15 2.851 (5) 144
O6B—H6B⋯O9ii 0.82 2.10 2.656 (8) 125
C8—H8B⋯O6Biii 0.96 2.32 3.280 (7) 178
Symmetry codes: (i) [-x+{\script{3\over 2}}, -y+1, z-{\script{1\over 2}}]; (ii) [x+{\script{1\over 2}}, -y+{\script{3\over 2}}, -z+1]; (iii) [-x+{\script{3\over 2}}], [-y+1, z+{\script{1\over 2}}].

In the absence of any atom with Z > 8, the refinements were carried out on merged data. The absolute structures are therefore indeterminate on the basis of the X-ray data and the Flack asymmetry parameters (Flack, 1983[Flack, H. D. (1983). Acta Cryst. A39, 876-881.]) are meaningless. The structural models were, however, set up in accord with the known D configuration of the pyran­ose ring. A recurrent problem in structures like those of (I)[link] and (II)[link] is considerable freedom of movement for some of the atoms of the substituent groups. For the acetyl groups, this primarily affects the oxo O atom and the methyl group and is attributable, therefore, to oscillation of the group by means of back and fore partial rotation about the C—O bond, e.g. C7—O1. A similar oscillatory motion about the C5—C6 bond applies to the carboxylic acid group in (I)[link]. These phenomena are particularly evident in the large and highly anisotropic displacement parameters associated with the motile atoms in the 292 K structure of (II)[link]. In the 120 K structure of (I)[link], movement of the atoms is much reduced and the anisotropic displacement parameters are more reasonable.

In the final stages of refinement, H atoms of methyl groups and those attached to tertiary C atoms were placed in calculated positions, with C—H = 0.98 and 1.00 Å, respectively, for (I)[link] and 0.96 and 0.98 Å for (II)[link], and refined with a riding model, with Uiso(H) = 1.5Ueq(Cmethyl) or 1.2Ueq(Ctertiary). The H atoms of the methyl­ene group in (II)[link] were created as two pairs of atoms, one pair for each component of the disorder of the OH group, and with corresponding occupancy factors, with C—H set to 0.97 Å, and they were refined with a riding model, with Uiso(H) = 1.2Ueq(C). The H atoms of the carboxylic acid group of (I)[link] and the OH group of (II)[link] were placed in calculated positions such as to provide idealized geometry and reasonable hydrogen bonding, with O—H = 0.84 and 0.82 Å for (I)[link] and (II)[link], respectively, and refined, along with the torsion angle about the C—O bond, with a riding model, with Uiso(H) = 1.5Ueq(O) in both cases. Peaks in a difference map provided approximate coordinates for the H atoms of the water mol­ecule of (I)[link]. These H atoms were then refined with isotropic displacement parameters.

Data collection: DENZO (Otwinowski & Minor, 1997[Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307-326. New York: Academic Press.]) and COLLECT (Nonius, 1998[Nonius (1998). COLLECT. Nonius BV, Delft, The Netherlands.]) for (I)[link]; SMART (Bruker, 1999[Bruker (1999). SMART (Version 5.054) and SAINT (Version 6.02a). Bruker AXS Inc., Madison, Wisconsin, USA.]) for (II)[link]. Cell refinement: DENZO and COLLECT for (I)[link]; SAINT (Bruker, 1999[Bruker (1999). SMART (Version 5.054) and SAINT (Version 6.02a). Bruker AXS Inc., Madison, Wisconsin, USA.]) for (II)[link]. Data reduction: DENZO and COLLECT for (I)[link]; SAINT for (II)[link]. For both compounds, program(s) used to solve structure: SHELXS97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.]); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2003[Spek, A. L. (2003). J. Appl. Cryst. 36, 7-13.]).

Supporting information


Comment top

The title compounds, the acid monohydrate, (I), previously reported by Fry (1955), and the anhydrous glucopyranose, (II), were prepared for use in esterifications with disaccharides.

The asymmetric unit of (I) and the molecule of (II) are shown in Figs. 1 and 2, respectively. The atom-labelling is similar and differs only for the O atoms with numeric values of 7 or greater. The compounds obviously differ in terms of the substituents attached to C5, namely CO2H in (I) and CH2OH in (II), and in the fact that (II) is anhydrous but (I) is the monohydrate. The values given in Table 1 show that the carboxylic acid group in (I) has the expected planar geometry, and bond lengths and angles are in the normal ranges. The hydroxyl group in (II), however, is disordered over two sites, O6A and O6B, with occupancies of 0.639?(7) and 0.361?(7), respectively. The torsion angles given in Table 1 show that these sites are related to one another by rotation of the OH group about the C5—C6 bond by 145.1 (5)°. The C6—O6A and C6—O6B bond lengths of 1.396 (6) and 1.338 (8) Å, respectively, are disappointingly disparate, but this is regarded as a side effect of the disorder. The disorder of the OH group has, as will be discussed later, a profound effect upon the hydrogen bonding in (II).

The pyranose rings, defined by O5/C1–C5, are very similar in the two structures, with bond lengths and angles in the expected ranges and similar chair conformations with puckering parameters (Cremer & Pople, 1975) [values for (II) in square brackets] of 0.594 (2) [0.595 (2) Å], 8.4 (2) [2.9 (2)] and 349.1 (15) [323 (6)°] for Q, θ and ϕ, respectively. The only significant differences between them reside in the torsion angles given in Table 2. These reflect differences in the orientation of the acetyl substituents with respect to the pyranose rings. The difference is greatest for the acetyl groups in the 2-position, less at the 3-position, still less at position 4 and least of all at position 1.

The two structures also differ significantly in their hydrogen-bonding. In (I), the hydrogen bonds given in Table 3 interconnect the molecules to form layers, as shown in Fig. 3, parallel to (101), within which the recurring motif is the trimolecular ring, of which two examples appear in Fig. 3. This connectivity comes about because the water molecule operates as both donor (twice) and acceptor.

In (II), with no water molecule, the possibilities for hydrogen-bond formation (Table 4) are reduced. They are, however, much influenced by the disorder of the OH group. The major component of the disorder, O6A/H6A, provides connectivity within chains propagated in the direction of (001) (Fig. 4), in which the molecules are connected edge-to-edge (type 1 chains). In contrast, the minor component, O6B/H6B, provides connectivity in chains of face-to-face molecules propagated in the direction of (100) (type 2 chains; Fig. 5). Because of the relative occupancies of the two sites, the type 1 chains are considered to be the dominant feature. Therefore, the type 2 connectivity is perceived as interconnecting and, at the same time, fragmenting the type 1 chains. The combination of these two types of connection provides incomplete two-dimensional connectivity between molecules which, as can be deduced from Figs. 4 and 5, are confined to corrugated layers parallel to (010), one unit cell thick and related to one another by cell translation. If every molecule acts as acceptor for one, and only one, hydrogen bond, this has an intriguing, if conjectural, side effect upon the manner in which the type 2 interactions might be introduced into the structure of (II). The introduction of an isolated type 2 hydrogen bond, as in Fig. 6(b), leaves an acceptor, A1, unused, while A2 becomes a dual acceptor. The introduction of a second complementary and adjacent type 2 interaction, as in Fig. 6(c), permits single-acceptor functionality for all molecules.

The descriptions just given consider only the strong O—H···O hydrogen bonds given in Tables 3 and 4. Weaker secondary O—H···O hydrogen bonds involving the H atoms of the water molecule are also present in (I) and still weaker C—H···O interactions are present in both structures. Many of these weaker intermolecular interactions simply parallel or reinforce some of the primary hydrogen-bonds.

Experimental top

Compound (I) was prepared as follows. Glucuronic acid (5.00 g, 26 mmol) was added to a stirred solution of acetic anhydride (25 ml, 245 mmol) and sulfuric acid (3 drops, Concentration?). The temperature was allowed to reach 323 K and extra glucuronic acid (5.00 g, 26 mmol) was added. The reaction mixture was maintained at 323–333 K for 1 h with stirring and then cooled to room temperature. Water (75 ml) was added to the stirred solution. After 20 min, crystals of the monohydrate, (I), which had separated out of the solution, were collected and washed with water. Yield: 9.76 g, 49.8%; m.p. 369–372 K; [α]D24 (c = 3, CHCl3) 18.5; literature values for material recrystallized from toluene: m.p. 425–427 K; [α]D (CHCl3) 16.3 (Fry, 1955). Spectroscopic analysis: 1H NMR (250 MHz, CDCl3, δ, p.p.m.): 1.99 (s, 3H, Me), 2.01 (s, 3H, Me), 2.03 (s, 3H, Me), 2.07 (s, 3H, Me), 4.62 (d, 1H, J = 9.16 Hz, H6), 5.11 (dd, 1H, J = 6.8 and 8.5 Hz, H2), 5.25 (t, 1H, J = 8.5 Hz, H3), 5.41 (t, 1H, J = 8.5 Hz, H4), 5.83 (d, 1H, J = 6.8 Hz, H1); 13C NMR (63 MHz, CDCl3, δ, p.p.m.): 20.5, 20.8, 68.9, 70.2, 72.0, 73.1, 97.4, 166.4, 168.8, 169.2, 169.3, 169.9; IR (KBr, ν, cm−1): 3608–3401, 1761, 1747, 1618. MS (ES+): 385.2 [100%, M+Na], 401.1 [8%, M+K]. The monohydrate, (I), used in the X-ray determination was recrystallized from 1:1 acetone–water.

Compound (II) was prepared in two stages. Firstly, simulaneous acetylation at positions 1–4 and protection of O6 with a trityl group was carried out on commercially available β-D-glucose in the manner described by Talley (1963) with procedural details as follows. To a hot solution of anhydrous D-glucose (20.0 g, 110 mmol) and trityl chloride (33.5 g, 120 mmol) in pyridine (100 ml) was added acetic anhydride (50 ml, 490 mmol). After stirring for 24 h, the reaction mixture was evaporated at reduced pressure to a syrup. The syrup was added to water, stirred and the resulting precipitate filtered and washed with water. The precipitate was dried and yielded 25.8 g (39%) of the precursor of (II) (m.p. 438–439 K). Thereafter, Amberlite IR 20 resin (20 g) and water (1 ml) were added to a solution of the precursor (20 g, 37 mmol) in CH3CN (100 ml). The stirred solution was heated at 333 K for 20 h. The reaction mixture was hot-filtered to remove the resin and, on cooling, a white precipitate formed from the reaction mixture. The precipitate was filtered off, washed with CH3CN, and the filtrate and washings combined. The solvent was removed at reduced pressure. A solution of the resulting solid in CH2Cl2 was dried by the addition of anhydrous CaCl2, which was then removed by filtration and the solvent removed from the filtrate, under reduced pressure. The solid (II) obtained was crystallized initially from methyl tert-butyl ether. Further recrystallization from diethyl ether yielded (II) in its final form. Yield: 4.1 g (37%); m.p. 403–404 K; [α]D (c = 4, CHCl3) 11.63; literature value: [α]D (CHCl3) 12 (Ding et al., 1997; Horrobin et al., 1998). Spectroscopic analysis: 1H NMR (500 MHz, CDCl3, δ, p.p.m.): 1.99 (s, 3H, Me), 2.00 (s, 3H, Me), 2.03 (s, 3H, Me), 2.08 (s, 3H, Me), 3.55 (dd, 1H, J = 4.2 and 12.5 Hz, H6), 3.62 (ddd, 1H, J = 2.3, 4.2 and 9.7 Hz, H5), 3.73 (dd, 1H, J = 2.3 and 12.5 Hz, H6), 5.07 (dd and t, 2H, J = 8.4 and 9.7 Hz, H2, 4), 5.27 (t, 1H, J = 9.7 Hz, H3), 5.70 (d, 1H, J = 8.4 Hz, H1); 13C NMR (63 MHz, CDCl3, δ, p.p.m.): 20.6, 20.8, 60.8, 68.2, 70.4, 72.6, 77.6, 91.7, 169.1, 169.3, 170.1, 170.3; IR (KBr, ν, cm−1): 3540, 2954, 1749. MS (ES+): 371.2 [100%, M+Na], 387.1 [25%, M+K].

Refinement top

In the absence of any atom of Z > 8, the refinements were carried out on merged data. The absolute structures are therefore indeterminate on the basis of the X-ray data and the Flack asymmetry parameters (Flack, 1983) are meaningless. The structural models were, however, set up in accord with the known D configuration of the pyranose ring. A recurrent problem in structures like those of (I) and (II) is considerable freedom of movement for some of the atoms of the substituent groups. For the acetyl groups, this primarily affects the oxo O atom and the methyl group and is attributable, therefore, to oscillation of the group by means of back and fore partial rotation about the C–O bond, e.g. C7—O1. A similar oscillatory motion about the C5—C6 bond applies to the carboxylic acid group in (I). These phenomena are particularly evident in the large and highly anisotropic displacement parameters associated with the motile atoms in the 292 K structure of (II). In the 120 K structure of (I), movement of the atoms is much reduced and the anisotropic displacement parameters are more reasonable.

In the final stages of refinement, H atoms of methyl groups and those attached to tertiary C atoms were placed in calculated positions with C—H = 0.98 and 1.00 Å, respectively, for (I) and 0.96 and 0.98 Å, respectively, for (II), and refined with a riding model, with Uiso(H) = 1.5Ueq(Cmethyl) or 1.2Ueq(Ctertiary). The H atoms of the methylene group in (II) were created as two pairs of atoms, one pair for each component of the disorder of the OH group, and with corresponding occupancy factors, with C—H set to 0.97 Å, and they were refined with a riding model, with Uiso(H) = 1.2Ueq(C). The H atoms of the carboxylic acid group of (I) and the OH group of (II) were placed in calculated positions such as to provide idealized geometry and reasonable hydrogen bonding, with O—H = 0.84 and 0.82 Å for (I) and (II), respectively, and refined, along with the torsion angle about the C—O bond, with a riding model, with Uiso(H) = 1.5Ueq(O) in both cases. Peaks in a difference map provided approximate coordinates for the H atoms of the water molecule of (I). These H atoms were then refined with isotropic displacement parameters.

Computing details top

Data collection: DENZO (Otwinowski & Minor, 1997) and COLLECT (Nonius, 1998) for (I); SMART (Bruker, 1999) for (II). Cell refinement: DENZO and COLLECT for (I); SAINT (Bruker, 1999) for (II). Data reduction: DENZO and COLLECT for (I); SAINT for (II). For both compounds, program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2003).

Figures top
[Figure 1] Fig. 1. The asymmetric unit of (I). Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii. The dashed line represents an O—H···O hydrogen bond.
[Figure 2] Fig. 2. The molecule of (II), with displacement ellipsoids are drawn at the 20% probability level and H atoms are shown as small spheres of arbitrary radii. Only the major component of the twofold disorder of the OH group is shown.
[Figure 3] Fig. 3. A hydrogen-bonded layer of molecules in (I). Displacement ellipsoids are drawn at the 20% probability level and H atoms involved in hydrogen bonds (dashed lines) are shown as small spheres of arbitrary radii. Selected atoms are labelled. [Symmetry codes: (i) 2 − x, y − 1/2, 2 − z; (ii) 1 − x, 1/2 + y, 1 − z; (iii) x − 1, y, z − 1; (iv) 1 − x, y − 1/2, 1 − z; (v) x, y − 1, z.]
[Figure 4] Fig. 4. A type 1 chain (see text) in (II). Displacement ellipsoids are drawn at the 10% probability level and H atoms involved in hydrogen bonds (dashed lines) are shown as small spheres of arbitrary radii. Selected atoms are labelled. [Symmetry codes: (i) 3/2 − x, 1 − y, z − 1/2; (iv) 3/2 − x, 1 − y, z + 1/2.]
[Figure 5] Fig. 5. A type 2 chain in (II). Displacement ellipsoids are drawn at the 10% probability level and H atoms involved in hydrogen bonds (dashed lines) are shown as small spheres of arbitrary radii. Selected atoms are labelled. [Symmetry codes: (ii) x + 1/2, 3/2 − y, 1 − z; (v) x − 1/2, 3/2 − y, 1 − z.]
[Figure 6] Fig. 6. Schematic representation of types 1 and 2 hydrogen bonding in (II). Molecules are represented by donor (D) and acceptor (A) centres joined by solid lines and hydrogen bonds by dashed lines. The arrangements shown are (a) a pair of type 1 chains; (b) as (a), but with the introduction of a single type 2 hydrogen bond, D1···A2; (c) as (b), but with the introduction of a second, complementary, type 2 hydrogen bond, D2···A1.
(I) 1,2,3,4-Tetra-O-acetyl-β-D-glucopyranuronic acid monohydrate top
Crystal data top
C14H18O11·H2OF(000) = 400
Mr = 380.30Dx = 1.399 Mg m3
Monoclinic, P21Melting point = 369–372 K
Hall symbol: P 2ybMo Kα radiation, λ = 0.71073 Å
a = 9.0644 (4) ÅCell parameters from 20602 reflections
b = 10.4661 (6) Åθ = 2.9–27.5°
c = 9.7703 (5) ŵ = 0.13 mm1
β = 103.131 (3)°T = 120 K
V = 902.66 (8) Å3Block, colourless
Z = 20.26 × 0.24 × 0.12 mm
Data collection top
Nonius KappaCCD area-detector
diffractometer
2131 independent reflections
Radiation source: Enraf–Nonius FR591 rotating anode1848 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.047
Detector resolution: 9.091 pixels mm-1θmax = 27.5°, θmin = 3.0°
ϕ and ω scans to fill the Ewald sphereh = 1111
Absorption correction: multi-scan
(SORTAV; Blessing, 1995, 1997)
k = 1213
Tmin = 0.842, Tmax = 0.988l = 1212
6414 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.038Hydrogen site location: geom and difmap
wR(F2) = 0.094H atoms treated by a mixture of independent and constrained refinement
S = 1.09 w = 1/[σ2(Fo2) + (0.0535P)2 + 0.0412P]
where P = (Fo2 + 2Fc2)/3
2131 reflections(Δ/σ)max < 0.001
248 parametersΔρmax = 0.26 e Å3
1 restraintΔρmin = 0.24 e Å3
Crystal data top
C14H18O11·H2OV = 902.66 (8) Å3
Mr = 380.30Z = 2
Monoclinic, P21Mo Kα radiation
a = 9.0644 (4) ŵ = 0.13 mm1
b = 10.4661 (6) ÅT = 120 K
c = 9.7703 (5) Å0.26 × 0.24 × 0.12 mm
β = 103.131 (3)°
Data collection top
Nonius KappaCCD area-detector
diffractometer
2131 independent reflections
Absorption correction: multi-scan
(SORTAV; Blessing, 1995, 1997)
1848 reflections with I > 2σ(I)
Tmin = 0.842, Tmax = 0.988Rint = 0.047
6414 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0381 restraint
wR(F2) = 0.094H atoms treated by a mixture of independent and constrained refinement
S = 1.09Δρmax = 0.26 e Å3
2131 reflectionsΔρmin = 0.24 e Å3
248 parameters
Special details top

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 (Å2) top
xyzUiso*/Ueq
O10.42805 (19)0.46522 (18)0.77167 (18)0.0276 (4)
O20.38300 (17)0.38689 (18)0.49169 (16)0.0242 (4)
O30.68869 (17)0.38490 (19)0.40710 (16)0.0251 (4)
O40.89148 (18)0.23428 (17)0.59788 (17)0.0232 (4)
O50.66600 (17)0.38688 (18)0.81798 (16)0.0219 (4)
O60.9919 (2)0.19442 (18)0.9011 (2)0.0331 (5)
H61.07220.19900.96390.050*
O70.94414 (18)0.38859 (19)0.98099 (18)0.0318 (4)
O80.3598 (2)0.3156 (3)0.9117 (2)0.0468 (6)
O90.4084 (2)0.54617 (18)0.34423 (19)0.0298 (4)
O100.5171 (2)0.2611 (2)0.26446 (19)0.0361 (5)
O111.0875 (2)0.3712 (2)0.6386 (2)0.0417 (5)
C10.5211 (2)0.3752 (3)0.7257 (2)0.0232 (5)
H10.48010.28670.72780.028*
C20.5319 (2)0.4128 (2)0.5774 (2)0.0217 (5)
H20.55720.50550.57340.026*
C30.6493 (2)0.3314 (3)0.5306 (2)0.0206 (5)
H30.61000.24250.51050.025*
C40.7976 (3)0.3288 (2)0.6406 (2)0.0212 (5)
H40.84780.41430.64580.025*
C50.7678 (3)0.2938 (2)0.7852 (2)0.0219 (5)
H50.72150.20680.78150.026*
C60.9125 (3)0.2992 (3)0.9019 (2)0.0237 (5)
C70.3517 (3)0.4233 (3)0.8689 (3)0.0354 (7)
C80.2641 (4)0.5306 (4)0.9125 (4)0.0502 (9)
H8A0.19520.49690.96790.075*
H8B0.20530.57400.82880.075*
H8C0.33430.59150.96960.075*
C90.3323 (3)0.4618 (3)0.3774 (2)0.0248 (5)
C100.1761 (3)0.4243 (3)0.3033 (3)0.0306 (6)
H10A0.13610.48690.22970.046*
H10B0.11090.42160.37070.046*
H10C0.17860.33980.26080.046*
C110.6147 (3)0.3407 (3)0.2791 (2)0.0293 (6)
C120.6709 (4)0.4071 (4)0.1661 (3)0.0478 (8)
H12A0.64360.49780.16480.072*
H12B0.62490.36850.07510.072*
H12C0.78140.39880.18410.072*
C131.0369 (3)0.2674 (3)0.6024 (3)0.0290 (6)
C141.1212 (3)0.1584 (3)0.5588 (4)0.0437 (8)
H14A1.21670.18940.53990.066*
H14B1.05980.11940.47350.066*
H14C1.14270.09470.63420.066*
O1W0.7790 (2)0.6501 (2)0.8916 (2)0.0343 (5)
H1W10.768 (5)0.564 (5)0.891 (5)0.079 (15)*
H1W20.696 (5)0.688 (4)0.885 (4)0.061 (12)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0245 (8)0.0329 (10)0.0274 (9)0.0003 (8)0.0102 (7)0.0020 (8)
O20.0191 (7)0.0290 (9)0.0228 (8)0.0002 (7)0.0010 (6)0.0026 (7)
O30.0244 (8)0.0332 (10)0.0175 (8)0.0000 (8)0.0043 (6)0.0025 (7)
O40.0206 (8)0.0237 (9)0.0256 (8)0.0017 (7)0.0056 (6)0.0013 (7)
O50.0187 (7)0.0283 (9)0.0175 (8)0.0017 (7)0.0019 (6)0.0023 (7)
O60.0318 (10)0.0298 (10)0.0305 (10)0.0060 (8)0.0083 (7)0.0030 (8)
O70.0281 (8)0.0352 (11)0.0289 (9)0.0015 (9)0.0001 (7)0.0072 (9)
O80.0455 (12)0.0637 (17)0.0366 (11)0.0072 (11)0.0207 (9)0.0087 (11)
O90.0320 (9)0.0272 (10)0.0295 (9)0.0058 (8)0.0057 (7)0.0058 (8)
O100.0353 (10)0.0430 (12)0.0265 (9)0.0012 (10)0.0001 (7)0.0064 (9)
O110.0261 (9)0.0393 (13)0.0606 (13)0.0071 (9)0.0120 (8)0.0122 (11)
C10.0200 (10)0.0269 (13)0.0224 (12)0.0015 (10)0.0045 (9)0.0001 (10)
C20.0190 (10)0.0246 (13)0.0204 (11)0.0027 (9)0.0027 (8)0.0002 (10)
C30.0201 (10)0.0268 (13)0.0139 (10)0.0003 (10)0.0014 (8)0.0028 (9)
C40.0205 (11)0.0231 (12)0.0202 (11)0.0008 (10)0.0047 (8)0.0000 (10)
C50.0217 (11)0.0228 (12)0.0207 (11)0.0001 (10)0.0039 (8)0.0009 (10)
C60.0222 (11)0.0300 (14)0.0168 (11)0.0022 (10)0.0000 (8)0.0020 (11)
C70.0254 (13)0.057 (2)0.0247 (12)0.0078 (13)0.0086 (10)0.0045 (14)
C80.0376 (16)0.064 (2)0.0567 (19)0.0084 (16)0.0279 (14)0.0226 (18)
C90.0250 (12)0.0267 (14)0.0208 (11)0.0089 (11)0.0014 (9)0.0026 (11)
C100.0282 (12)0.0346 (15)0.0237 (12)0.0045 (11)0.0055 (9)0.0033 (11)
C110.0280 (12)0.0417 (16)0.0166 (11)0.0096 (12)0.0012 (9)0.0017 (11)
C120.0462 (16)0.074 (3)0.0251 (14)0.0003 (17)0.0129 (12)0.0021 (15)
C130.0229 (12)0.0340 (16)0.0301 (13)0.0020 (12)0.0060 (9)0.0022 (12)
C140.0322 (15)0.0372 (17)0.067 (2)0.0080 (14)0.0213 (15)0.0013 (15)
O1W0.0298 (10)0.0291 (11)0.0384 (11)0.0007 (9)0.0038 (8)0.0021 (9)
Geometric parameters (Å, º) top
O1—C71.369 (3)C4—C51.541 (3)
O1—C11.405 (3)C4—H41.0000
O2—C91.357 (3)C5—C61.530 (3)
O2—C21.443 (3)C5—H51.0000
O3—C111.358 (3)C7—C81.493 (5)
O3—C31.447 (3)C8—H8A0.9800
O4—C131.354 (3)C8—H8B0.9800
O4—C41.428 (3)C8—H8C0.9800
O5—C11.419 (3)C9—C101.489 (3)
O5—C51.428 (3)C10—H10A0.9800
O6—C61.313 (3)C10—H10B0.9800
O6—H60.8400C10—H10C0.9800
O7—C61.206 (3)C11—C121.490 (4)
O8—C71.198 (4)C12—H12A0.9800
O9—C91.208 (3)C12—H12B0.9800
O10—C111.200 (4)C12—H12C0.9800
O11—C131.201 (3)C13—C141.488 (4)
C1—C21.526 (3)C14—H14A0.9800
C1—H11.0000C14—H14B0.9800
C2—C31.512 (3)C14—H14C0.9800
C2—H21.0000O1W—H1W10.91 (5)
C3—C41.519 (3)O1W—H1W20.84 (5)
C3—H31.0000
C7—O1—C1116.2 (2)O6—C6—C5110.1 (2)
C9—O2—C2117.78 (19)O8—C7—O1122.9 (3)
C11—O3—C3118.2 (2)O8—C7—C8127.0 (3)
C13—O4—C4117.0 (2)O1—C7—C8110.0 (3)
C1—O5—C5110.54 (18)C7—C8—H8A109.5
C6—O6—H6109.5C7—C8—H8B109.5
O1—C1—O5105.98 (19)H8A—C8—H8B109.5
O1—C1—C2107.6 (2)C7—C8—H8C109.5
O5—C1—C2109.32 (17)H8A—C8—H8C109.5
O1—C1—H1111.2H8B—C8—H8C109.5
O5—C1—H1111.2O9—C9—O2122.4 (2)
C2—C1—H1111.2O9—C9—C10126.8 (2)
O2—C2—C3110.38 (18)O2—C9—C10110.8 (2)
O2—C2—C1104.42 (17)C9—C10—H10A109.5
C3—C2—C1110.08 (19)C9—C10—H10B109.5
O2—C2—H2110.6H10A—C10—H10B109.5
C3—C2—H2110.6C9—C10—H10C109.5
C1—C2—H2110.6H10A—C10—H10C109.5
O3—C3—C2111.0 (2)H10B—C10—H10C109.5
O3—C3—C4104.51 (17)O10—C11—O3122.9 (2)
C2—C3—C4111.50 (18)O10—C11—C12127.1 (3)
O3—C3—H3109.9O3—C11—C12110.1 (3)
C2—C3—H3109.9C11—C12—H12A109.5
C4—C3—H3109.9C11—C12—H12B109.5
O4—C4—C3107.23 (18)H12A—C12—H12B109.5
O4—C4—C5110.08 (19)C11—C12—H12C109.5
C3—C4—C5110.00 (18)H12A—C12—H12C109.5
O4—C4—H4109.8H12B—C12—H12C109.5
C3—C4—H4109.8O11—C13—O4123.0 (2)
C5—C4—H4109.8O11—C13—C14126.2 (2)
O5—C5—C6107.23 (19)O4—C13—C14110.7 (2)
O5—C5—C4107.45 (18)C13—C14—H14A109.5
C6—C5—C4112.04 (18)C13—C14—H14B109.5
O5—C5—H5110.0H14A—C14—H14B109.5
C6—C5—H5110.0C13—C14—H14C109.5
C4—C5—H5110.0H14A—C14—H14C109.5
O7—C6—O6126.9 (2)H14B—C14—H14C109.5
O7—C6—C5123.0 (2)H1W1—O1W—H1W2112 (4)
C7—O1—C1—O590.4 (2)O3—C3—C4—C5171.00 (19)
C7—O1—C1—C2152.7 (2)C2—C3—C4—C551.0 (3)
C5—O5—C1—O1176.68 (18)C1—O5—C5—C6171.58 (18)
C5—O5—C1—C267.6 (2)C1—O5—C5—C467.8 (2)
C9—O2—C2—C393.0 (2)O4—C4—C5—O5176.35 (17)
C9—O2—C2—C1148.7 (2)C3—C4—C5—O558.4 (2)
O1—C1—C2—O270.1 (2)O4—C4—C5—C666.1 (3)
O5—C1—C2—O2175.24 (19)C3—C4—C5—C6175.9 (2)
O1—C1—C2—C3171.45 (18)O5—C5—C6—O717.8 (3)
O5—C1—C2—C356.8 (3)C4—C5—C6—O799.8 (3)
C11—O3—C3—C294.6 (3)O5—C5—C6—O6162.00 (19)
C11—O3—C3—C4145.0 (2)C4—C5—C6—O680.3 (3)
O2—C2—C3—O379.4 (2)C1—O1—C7—O81.4 (4)
C1—C2—C3—O3165.80 (18)C1—O1—C7—C8177.2 (2)
O2—C2—C3—C4164.47 (19)C2—O2—C9—O91.7 (3)
C1—C2—C3—C449.7 (3)C2—O2—C9—C10178.60 (19)
C13—O4—C4—C3133.2 (2)C3—O3—C11—O101.2 (4)
C13—O4—C4—C5107.2 (2)C3—O3—C11—C12180.0 (2)
O3—C3—C4—O469.3 (2)C4—O4—C13—O110.8 (4)
C2—C3—C4—O4170.71 (19)C4—O4—C13—C14178.5 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O6—H6···O1Wi0.841.792.592 (3)159
O1W—H1W1···O50.91 (5)2.12 (5)2.970 (3)155 (4)
O1W—H1W1···O70.91 (5)2.46 (5)3.146 (3)133 (4)
O1W—H1W2···O8ii0.84 (5)2.54 (4)3.062 (3)121 (3)
O1W—H1W2···O10iii0.84 (5)2.27 (5)3.003 (3)146 (4)
C3—H3···O9iv1.002.523.312 (3)136
C5—H5···O9iv1.002.253.154 (3)150
C8—H8A···O7v0.982.573.457 (4)150
C10—H10C···O1Wiv0.982.563.519 (4)165
Symmetry codes: (i) x+2, y1/2, z+2; (ii) x+1, y+1/2, z+2; (iii) x+1, y+1/2, z+1; (iv) x+1, y1/2, z+1; (v) x1, y, z.
(II) 1,2,3,4-Tetra-O-acetyl-beta-D-glucopyranose top
Crystal data top
C14H20O10Dx = 1.273 Mg m3
Mr = 348.30Melting point = 403–404 K
Orthorhombic, P212121Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2abCell parameters from 4864 reflections
a = 9.4830 (8) Åθ = 2.7–24.3°
b = 12.6536 (12) ŵ = 0.11 mm1
c = 15.1455 (14) ÅT = 292 K
V = 1817.4 (3) Å3Block, colourless
Z = 40.50 × 0.50 × 0.27 mm
F(000) = 736
Data collection top
Bruker SMART 1000 CCD area detector
diffractometer
3702 independent reflections
Radiation source: fine-focus sealed tube1921 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.040
ϕ and ω scansθmax = 32.6°, θmin = 2.1°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1999)
h = 1410
Tmin = 0.876, Tmax = 0.928k = 1819
21264 measured reflectionsl = 2222
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.046Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.148H-atom parameters constrained
S = 1.00 w = 1/[σ2(Fo2) + (0.0739P)2 + 0.0408P]
where P = (Fo2 + 2Fc2)/3
3702 reflections(Δ/σ)max < 0.001
233 parametersΔρmax = 0.17 e Å3
0 restraintsΔρmin = 0.17 e Å3
Crystal data top
C14H20O10V = 1817.4 (3) Å3
Mr = 348.30Z = 4
Orthorhombic, P212121Mo Kα radiation
a = 9.4830 (8) ŵ = 0.11 mm1
b = 12.6536 (12) ÅT = 292 K
c = 15.1455 (14) Å0.50 × 0.50 × 0.27 mm
Data collection top
Bruker SMART 1000 CCD area detector
diffractometer
3702 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1999)
1921 reflections with I > 2σ(I)
Tmin = 0.876, Tmax = 0.928Rint = 0.040
21264 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0460 restraints
wR(F2) = 0.148H-atom parameters constrained
S = 1.00Δρmax = 0.17 e Å3
3702 reflectionsΔρmin = 0.17 e Å3
233 parameters
Special details top

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 (Å2) top
xyzUiso*/UeqOcc. (<1)
O10.67707 (19)0.45363 (14)0.59308 (13)0.0757 (5)
O20.6268 (2)0.62515 (14)0.71393 (10)0.0717 (5)
O30.66461 (15)0.82407 (12)0.63465 (10)0.0613 (4)
O40.54167 (15)0.84355 (13)0.46397 (10)0.0614 (4)
O50.62182 (18)0.56104 (13)0.47920 (10)0.0675 (4)
O6A0.5076 (4)0.5727 (4)0.3022 (3)0.133 (2)0.639 (7)
H6A0.55020.51740.31130.200*0.639 (7)
O6B0.7015 (8)0.6892 (8)0.3202 (4)0.122 (3)0.361 (7)
H6B0.76290.66220.35100.183*0.361 (7)
O70.4937 (3)0.3491 (2)0.5636 (3)0.1450 (12)
O80.8541 (3)0.6167 (3)0.74844 (16)0.1298 (10)
O90.4644 (3)0.8815 (3)0.6928 (3)0.1668 (17)
O100.7454 (2)0.9139 (2)0.4227 (2)0.1480 (15)
C10.5986 (3)0.5440 (2)0.57034 (15)0.0639 (5)
H10.49820.53440.58320.077*
C20.6596 (2)0.63621 (18)0.62156 (13)0.0572 (5)
H20.76200.63910.61330.069*
C30.5935 (2)0.73799 (17)0.59103 (12)0.0531 (4)
H30.49290.73870.60590.064*
C40.6126 (2)0.7490 (2)0.49211 (13)0.0558 (5)
H40.71330.75440.47820.067*
C50.5505 (2)0.6528 (2)0.44597 (14)0.0631 (6)
H50.44930.64780.45850.076*
C60.5748 (3)0.6553 (3)0.34671 (17)0.0916 (10)
H6C0.54080.72200.32350.110*0.639 (7)
H6D0.67530.65140.33520.110*0.639 (7)
H6E0.56070.58440.32380.110*0.361 (7)
H6F0.50350.70030.32030.110*0.361 (7)
C70.6134 (5)0.3575 (3)0.5863 (3)0.0998 (10)
C80.7125 (5)0.2721 (3)0.6130 (3)0.1273 (14)
H8A0.66710.20480.60650.191*
H8B0.73970.28210.67350.191*
H8C0.79480.27450.57610.191*
C90.7349 (5)0.6212 (3)0.77096 (19)0.0897 (9)
C100.6840 (5)0.6217 (3)0.86415 (19)0.1226 (15)
H10A0.66410.69300.88190.184*
H10B0.75540.59250.90190.184*
H10C0.59970.58000.86860.184*
C110.5885 (3)0.8906 (3)0.6840 (2)0.0887 (9)
C120.6766 (4)0.9731 (4)0.7243 (3)0.1328 (17)
H12A0.71710.94670.77810.199*
H12B0.61961.03390.73710.199*
H12C0.75050.99250.68420.199*
C130.6220 (3)0.9231 (2)0.43415 (17)0.0774 (7)
C140.5390 (3)1.0201 (3)0.4176 (2)0.0896 (8)
H14A0.49631.01600.36020.134*
H14B0.60011.08050.42000.134*
H14C0.46691.02680.46170.134*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0745 (10)0.0616 (9)0.0910 (12)0.0006 (8)0.0002 (9)0.0027 (8)
O20.0830 (11)0.0792 (10)0.0528 (8)0.0053 (9)0.0041 (8)0.0133 (8)
O30.0588 (8)0.0640 (9)0.0611 (8)0.0014 (7)0.0035 (7)0.0042 (7)
O40.0455 (7)0.0794 (10)0.0593 (8)0.0017 (7)0.0015 (6)0.0139 (7)
O50.0631 (9)0.0768 (10)0.0625 (9)0.0054 (8)0.0033 (7)0.0108 (8)
O6A0.113 (3)0.190 (5)0.097 (3)0.056 (3)0.044 (2)0.075 (3)
O6B0.114 (5)0.179 (8)0.073 (4)0.010 (5)0.029 (3)0.003 (4)
O70.123 (2)0.0924 (18)0.220 (3)0.0376 (16)0.027 (2)0.0108 (19)
O80.1071 (19)0.192 (3)0.0899 (15)0.022 (2)0.0325 (14)0.0199 (17)
O90.0793 (16)0.189 (3)0.232 (4)0.0032 (18)0.0184 (19)0.131 (3)
O100.0571 (12)0.159 (2)0.227 (4)0.0094 (14)0.0042 (15)0.119 (3)
C10.0570 (12)0.0678 (13)0.0668 (13)0.0024 (11)0.0051 (10)0.0016 (11)
C20.0552 (11)0.0668 (12)0.0496 (10)0.0007 (10)0.0023 (8)0.0065 (10)
C30.0483 (10)0.0638 (12)0.0472 (9)0.0026 (9)0.0006 (8)0.0010 (9)
C40.0419 (9)0.0772 (12)0.0484 (9)0.0023 (10)0.0018 (7)0.0069 (9)
C50.0454 (10)0.0879 (16)0.0561 (11)0.0085 (11)0.0015 (8)0.0084 (11)
C60.089 (2)0.129 (3)0.0562 (13)0.0310 (18)0.0100 (13)0.0167 (16)
C70.116 (3)0.0696 (18)0.114 (2)0.0149 (19)0.010 (2)0.0058 (17)
C80.170 (4)0.0660 (19)0.146 (3)0.006 (2)0.002 (3)0.016 (2)
C90.125 (3)0.0800 (19)0.0645 (15)0.0238 (18)0.0126 (17)0.0095 (13)
C100.182 (4)0.128 (3)0.0570 (14)0.061 (3)0.010 (2)0.0102 (17)
C110.0734 (18)0.0921 (19)0.101 (2)0.0081 (15)0.0096 (15)0.0323 (17)
C120.115 (3)0.121 (3)0.163 (4)0.006 (2)0.017 (3)0.070 (3)
C130.0597 (14)0.0988 (19)0.0739 (15)0.0089 (13)0.0099 (12)0.0324 (14)
C140.096 (2)0.0870 (19)0.0860 (18)0.0011 (16)0.0093 (16)0.0215 (15)
Geometric parameters (Å, º) top
O1—C71.362 (4)C4—C51.522 (3)
O1—C11.407 (3)C4—H40.9800
O2—C91.341 (4)C5—C61.521 (3)
O2—C21.440 (2)C5—H50.9800
O3—C111.338 (3)C6—H6C0.9700
O3—C31.441 (3)C6—H6D0.9700
O4—C131.341 (3)C6—H6E0.9700
O4—C41.437 (3)C6—H6F0.9700
O5—C11.414 (3)C7—C81.488 (5)
O5—C51.435 (3)C8—H8A0.9600
O6A—C61.396 (6)C8—H8B0.9600
O6A—H6A0.8200C8—H8C0.9600
O6B—C61.338 (8)C9—C101.492 (5)
O6B—H6B0.8200C10—H10A0.9600
O7—C71.190 (5)C10—H10B0.9600
O8—C91.182 (4)C10—H10C0.9600
O9—C111.190 (4)C11—C121.469 (5)
O10—C131.189 (4)C12—H12A0.9600
C1—C21.515 (3)C12—H12B0.9600
C1—H10.9800C12—H12C0.9600
C2—C31.505 (3)C13—C141.479 (4)
C2—H20.9800C14—H14A0.9600
C3—C41.516 (3)C14—H14B0.9600
C3—H30.9800C14—H14C0.9600
C7—O1—C1118.2 (2)H6C—C6—H6D107.8
C9—O2—C2117.7 (2)O6B—C6—H6E108.3
C11—O3—C3118.67 (19)C5—C6—H6E108.3
C13—O4—C4117.34 (17)O6B—C6—H6F108.3
C1—O5—C5113.09 (17)C5—C6—H6F108.3
C6—O6A—H6A109.5H6E—C6—H6F107.4
C6—O6B—H6B109.5O7—C7—O1121.6 (3)
O1—C1—O5106.28 (19)O7—C7—C8128.0 (3)
O1—C1—C2107.39 (19)O1—C7—C8110.3 (3)
O5—C1—C2108.87 (19)C7—C8—H8A109.5
O1—C1—H1111.4C7—C8—H8B109.5
O5—C1—H1111.4H8A—C8—H8B109.5
C2—C1—H1111.4C7—C8—H8C109.5
O2—C2—C3106.97 (17)H8A—C8—H8C109.5
O2—C2—C1109.90 (18)H8B—C8—H8C109.5
C3—C2—C1110.03 (17)O8—C9—O2123.1 (3)
O2—C2—H2110.0O8—C9—C10125.6 (3)
C3—C2—H2110.0O2—C9—C10111.2 (4)
C1—C2—H2110.0C9—C10—H10A109.5
O3—C3—C2108.13 (16)C9—C10—H10B109.5
O3—C3—C4109.14 (18)H10A—C10—H10B109.5
C2—C3—C4109.43 (18)C9—C10—H10C109.5
O3—C3—H3110.0H10A—C10—H10C109.5
C2—C3—H3110.0H10B—C10—H10C109.5
C4—C3—H3110.0O9—C11—O3122.3 (3)
O4—C4—C3108.29 (18)O9—C11—C12125.8 (3)
O4—C4—C5110.40 (16)O3—C11—C12111.9 (3)
C3—C4—C5109.53 (19)C11—C12—H12A109.5
O4—C4—H4109.5C11—C12—H12B109.5
C3—C4—H4109.5H12A—C12—H12B109.5
C5—C4—H4109.5C11—C12—H12C109.5
O5—C5—C6106.9 (2)H12A—C12—H12C109.5
O5—C5—C4107.68 (16)H12B—C12—H12C109.5
C6—C5—C4112.3 (2)O10—C13—O4122.3 (3)
O5—C5—H5110.0O10—C13—C14125.5 (3)
C6—C5—H5110.0O4—C13—C14112.2 (2)
C4—C5—H5110.0C13—C14—H14A109.5
O6B—C6—C5116.0 (4)C13—C14—H14B109.5
O6A—C6—C5113.1 (4)H14A—C14—H14B109.5
O6A—C6—H6C109.0C13—C14—H14C109.5
C5—C6—H6C109.0H14A—C14—H14C109.5
O6A—C6—H6D109.0H14B—C14—H14C109.5
C5—C6—H6D109.0
C7—O1—C1—O589.9 (3)O3—C3—C4—C5174.43 (16)
C7—O1—C1—C2153.7 (2)C2—C3—C4—C556.3 (2)
C5—O5—C1—O1178.74 (18)C1—O5—C5—C6175.2 (2)
C5—O5—C1—C263.4 (2)C1—O5—C5—C463.9 (2)
C9—O2—C2—C3119.2 (2)O4—C4—C5—O5177.86 (16)
C9—O2—C2—C1121.4 (2)C3—C4—C5—O558.7 (2)
O1—C1—C2—O270.2 (2)O4—C4—C5—C664.7 (2)
O5—C1—C2—O2175.16 (18)C3—C4—C5—C6176.2 (2)
O1—C1—C2—C3172.29 (17)O5—C5—C6—O6B77.5 (6)
O5—C1—C2—C357.6 (2)C4—C5—C6—O6B40.4 (6)
C11—O3—C3—C2122.0 (2)O5—C5—C6—O6A67.6 (3)
C11—O3—C3—C4119.0 (3)C4—C5—C6—O6A174.5 (3)
O2—C2—C3—O366.5 (2)C1—O1—C7—O71.5 (5)
C1—C2—C3—O3174.11 (17)C1—O1—C7—C8179.9 (3)
O2—C2—C3—C4174.68 (18)C2—O2—C9—O87.0 (5)
C1—C2—C3—C455.3 (2)C2—O2—C9—C10173.7 (3)
C13—O4—C4—C3112.7 (2)C3—O3—C11—O90.3 (5)
C13—O4—C4—C5127.4 (2)C3—O3—C11—C12179.5 (3)
O3—C3—C4—O465.1 (2)C4—O4—C13—O107.3 (4)
C2—C3—C4—O4176.73 (16)C4—O4—C13—C14173.0 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O6A—H6A···O8i0.822.152.851 (5)144
O6B—H6B···O9ii0.822.102.656 (8)125
C1—H1···O10iii0.982.493.394 (3)154
C8—H8B···O6Biv0.962.323.280 (7)178
C10—H10A···O7v0.962.613.510 (5)156
Symmetry codes: (i) x+3/2, y+1, z1/2; (ii) x+1/2, y+3/2, z+1; (iii) x1/2, y+3/2, z+1; (iv) x+3/2, y+1, z+1/2; (v) x+1, y+1/2, z+3/2.

Experimental details

(I)(II)
Crystal data
Chemical formulaC14H18O11·H2OC14H20O10
Mr380.30348.30
Crystal system, space groupMonoclinic, P21Orthorhombic, P212121
Temperature (K)120292
a, b, c (Å)9.0644 (4), 10.4661 (6), 9.7703 (5)9.4830 (8), 12.6536 (12), 15.1455 (14)
α, β, γ (°)90, 103.131 (3), 9090, 90, 90
V3)902.66 (8)1817.4 (3)
Z24
Radiation typeMo KαMo Kα
µ (mm1)0.130.11
Crystal size (mm)0.26 × 0.24 × 0.120.50 × 0.50 × 0.27
Data collection
DiffractometerNonius KappaCCD area-detector
diffractometer
Bruker SMART 1000 CCD area detector
diffractometer
Absorption correctionMulti-scan
(SORTAV; Blessing, 1995, 1997)
Multi-scan
(SADABS; Sheldrick, 1999)
Tmin, Tmax0.842, 0.9880.876, 0.928
No. of measured, independent and
observed [I > 2σ(I)] reflections
6414, 2131, 1848 21264, 3702, 1921
Rint0.0470.040
(sin θ/λ)max1)0.6490.758
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.038, 0.094, 1.09 0.046, 0.148, 1.00
No. of reflections21313702
No. of parameters248233
No. of restraints10
H-atom treatmentH atoms treated by a mixture of independent and constrained refinementH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.26, 0.240.17, 0.17

Computer programs: DENZO (Otwinowski & Minor, 1997) and COLLECT (Nonius, 1998), SMART (Bruker, 1999), DENZO and COLLECT, SAINT (Bruker, 1999), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Farrugia, 1997), SHELXL97 and PLATON (Spek, 2003).

Hydrogen-bond geometry (Å, º) for (I) top
D—H···AD—HH···AD···AD—H···A
O6—H6···O1Wi0.841.792.592 (3)159
O1W—H1W1···O50.91 (5)2.12 (5)2.970 (3)155 (4)
O1W—H1W2···O10ii0.84 (5)2.27 (5)3.003 (3)146 (4)
Symmetry codes: (i) x+2, y1/2, z+2; (ii) x+1, y+1/2, z+1.
Hydrogen-bond geometry (Å, º) for (II) top
D—H···AD—HH···AD···AD—H···A
O6A—H6A···O8i0.822.152.851 (5)144
O6B—H6B···O9ii0.822.102.656 (8)125
C8—H8B···O6Biii0.962.323.280 (7)178
Symmetry codes: (i) x+3/2, y+1, z1/2; (ii) x+1/2, y+3/2, z+1; (iii) x+3/2, y+1, z+1/2.
Table 1. Selected geometric parameters (Å, °) for (I) and (II) top
III
C6—O61.313 (3)C6—O6A1.396 (6)
C6—O71.206 (3)C6—O6B1.338 (8)
C5—C6—O6110.1 (2)C5—C6—O6A113.1 (4)
C5—C6—O7123.0 (2)C5—C6—O6B116.0 (4)
O6—C6—O7126.9 (2)
O5-C5-C6-O6162.00 (19)O5-C5-C6-O6A67.6 (3)
O5-C5-C6-O7-17.8 (3)O5-C5-C6-O6B-77.5 (6)
C4-C5-C6-O6-80.3 (3)C4-C5-C6-O6A-174.5 (3)
C4-C5-C6-O799.8 (3)C4-C5-C6-O6B40.4 (6)
Table 2. Selected torsion angles (°) for (I) and (II) top
III
C7-O1-C1-O5-90.4 (2)-89.9 (3)
C7-O1-C1-C2152.7 (2)153.7 (2)
C9-O2-C2-C3-93.0 (2)-119.2 (2)
C9-O2-C2-C1148.7 (2)121.4 (2)
C11-O3-C3-C2-94.6 (3)-122.0 (2)
C11-O3-C3-C4145.0 (2)119.0 (3)
C13-O4-C4-C3133.2 (2)112.7 (2)
C13-O4-C4-C5-107.2 (2)-127.4 (2)
 

Acknowledgements

The use of the EPSRC X-ray Crystallographic Service at Southampton and the valuable assistance of the staff there are gratefully acknowledged. We thank Quadrant Drug Delivery Ltd for providing the funding for this work.

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