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

Article abstract of DOI:10.1107/S0108270105034979

The structure of the title acid as the monohydrate, C₁₄H ₁₈O₁₁·H₂O, displays hydrogen bonding which connects the molecules in layers parallel to (101). 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).

Full text of DOI:10.1107/S0108270105034979

organic compounds
Acta Crystallographica Section C
Crystal Structure
Communications
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 C5ÐC6 bond by 145.1 (5)ꢀ. The C6ÐO6A
Ê
ISSN 0108-2701
and C6ÐO6B bond lengths of 1.396 (6) and 1.338 (8) A,
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).
1,2,3,4-Tetra-O-acetyl-b-D-gluco-
pyranuronic acid monohydrate at
120 K and anhydrous 1,2,3,4-tetra-
O-acetyl-b-D-glucopyranose at 292 K
The pyranose rings, de®ned 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) [values for (IIꢀ)
Ê
Ê
in square brackets] of 0.594 (2) A [0.595 (2) A], 8.4 (2)
[2.9 (2)ꢀ] and 349.1 (15)ꢀ [323 (6)ꢀ] for Q, ꢀ and ', respectively.
The only signi®cant differences between them reside in the
torsion angles given in Table 2. These re¯ect differences in the
orientation of the acetyl substituents with respect to the
pyranose rings. The difference is greatest for the acetyl groups
Thomas C. Baddeley,a R. Alan Howie,a* Janet M. S.
Skaklea and James L. Wardellb
aDepartment of Chemistry, University of Aberdeen, Meston Walk, Aberdeen
b
Â
Ã
AB24 3UE, Scotland, and Departamento de Quõmica Inorganica, Instituto de
Â
Quõmica, 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,
C14H18O11ÁH2O, displays hydrogen bonding which connects
the molecules in layers parallel to (101). 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),
previously reported by Fry (1955), and the anhydrous
glucopyranose, (II), were prepared for use in esteri®cations
with disaccharides.
Figure 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 OÐHÁ Á ÁO hydrogen bond.
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),
Figure 2
The molecule of (II), 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.
Acta Cryst. (2005). C61, o711±o714
DOI: 10.1107/S0108270105034979
# 2005 International Union of Crystallography o711

organic compounds
in the 2-position, less at the 3-position, still less at position 4
and least of all at position 1.
of these two types of connection provides incomplete two-
dimensional connectivity between molecules which, as can be
deduced from Figs. 4 and 5, are con®ned 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 two structures also differ signi®cantly in their hydrogen
bonding. In (I), the hydrogen bonds given in Table 3 inter-
connect 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 oper-
ates 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 in¯uenced by the disorder of the OH group.
The major component of the disorder, O6AÐH6A, 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, O6BÐ
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
Figure 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 12, 2 z; (ii)
1
z.]
Figure 5
A type 2 chain (see Comment) 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
x, 12 + y, 1 z; (iii) x 1, y, z 1; (iv) 1 x, y 21, 1 z; (v) x, y 1,
atoms are labelled. [Symmetry codes: (ii) x + 12,
y, 1 z; (v) x
,
2
3
2
1
3
2
y, 1 z.]
Figure 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, D1Á Á ÁA2; (c) as (b), but with the
introduction of a second, complementary, type 2 hydrogen bond,
D2Á Á ÁA1.
Figure 4
A type 1 chain (see Comment) 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
3
2
3
2
atoms are labelled. [Symmetry codes: (i)
y, z + 12.]
x, 1 y, z 12; (iv)
x,
1
ꢁ
o712 Baddeley et al. C14H18O11ÁH2O and C14H20O10
Acta Cryst. (2005). C61, o711±o714

organic compounds
Table 1
Selected geometric parameters for (I) and (II) (A, ).
The descriptions just given consider only the strong OÐ
HÁ Á ÁO hydrogen bonds given in Tables 3 and 4. Weaker
secondary OÐHÁ Á ÁO hydrogen bonds involving the H atoms
of the water molecule are also present in (I) and still weaker
CÐHÁ Á ÁO interactions are present in both structures. Many of
these weaker intermolecular interactions simply parallel or
reinforce some of the primary hydrogen bonds.
ꢀ
Ê
(I)
(II)
C6ÐO6
C6ÐO7
1.313 (3)
1.206 (3)
C6ÐO6A
C6ÐO6B
1.396 (6)
1.338 (8)
C5ÐC6ÐO6
C5ÐC6ÐO7
O6ÐC6ÐO7
110.1 (2)
123.0 (2)
126.9 (2)
C5ÐC6ÐO6A
C5ÐC6ÐO6B
113.1 (4)
116.0 (4)
Experimental
O5ÐC5ÐC6ÐO6
O5ÐC5ÐC6ÐO7
C4ÐC5ÐC6ÐO6
C4ÐC5ÐC6ÐO7
162.00 (19)
17.8 (3)
80.3 (3)
O5ÐC5ÐC6ÐO6A
O5ÐC5ÐC6ÐO6B
C4ÐC5ÐC6ÐO6A
C4ÐC5ÐC6ÐO6B
67.6 (3)
77.5 (6)
174.5 (3)
40.4 (6)
For the preparation of compound (I), 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), which had separated out of the solution,
were collected and washed with water (yield: 9.76 g, 49.8%); m.p.
369±372 K; [ꢁ]D24 (c = 3, CHCl3) 18.5; literature values for material
recrystallized from toluene: m.p. 425±427 K; [ꢁ]D (CHCl3) 16.3 (Fry,
99.8 (3)
Table 2
Selected torsion angles (ꢀ) for (I) and (II).
(I)
(II)
C7ÐO1ÐC1ÐO5
C7ÐO1ÐC1ÐC2
C9ÐO2ÐC2ÐC3
C9ÐO2ÐC2ÐC1
C11ÐO3ÐC3ÐC2
C11ÐO3ÐC3ÐC4
C13ÐO4ÐC4ÐC3
C13ÐO4ÐC4ÐC5
90.4 (2)
152.7 (2)
93.0 (2)
148.7 (2)
94.6 (3)
145.0 (2)
133.2 (2)
107.2 (2)
89.9 (3)
153.7 (2)
119.2 (2)
121.4 (2)
122.0 (2)
119.0 (3)
112.7 (2)
127.4 (2)
1
1955). H NMR (250 MHz, CDCl3): ꢂ 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): ꢂ 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, ꢃ, cm 1): 3608±3401, 1761, 1747, 1618.
MS (ES+): 385.2 [100%, M + Na], 401.1 [8%, M + K]. The mono-
hydrate, (I), used in the X-ray determination was recrystallized from
an acetone±water (1:1 v/v) solution.
Compound (I)
Crystal data
3
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 ꢄ-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 give a syrup. The syrup was added
to water, stirred and the resulting precipitate ®ltered 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-®ltered to remove the
resin and, on cooling, a white precipitate formed from the reaction
mixture. The precipitate was ®ltered off, washed with CH3CN, and the
®ltrate 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 ®ltration;
the solvent was removed from the ®ltrate under reduced pressure.
The solid (II) obtained was crystallized initially from methyl tert-butyl
ether. Further recrystallization from diethyl ether yielded (II) in its
®nal form (yield: 4.1 g, 37%); m.p. 403±404 K; [ꢁ]D (c = 4, CHCl3)
11.63; literature value: [ꢁ]D (CHCl3) 12 (Ding et al., 1997; Horrobin et
al., 1998). 1H NMR (500 MHz, CDCl3): ꢂ 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): ꢂ, 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, ꢃ, cm 1): 3540, 2954, 1749. MS (ES+):
371.2 [100%, M + Na], 387.1 [25%, M + K].
C14H18O11ÁH2O
Dx = 1.399 Mg m
Mo Kꢁ radiation
Mr = 380.30
Monoclinic, P21
Cell parameters from 20602
re¯ections
Ê
a = 9.0644 (4) A
ꢀ = 2.9±27.5ꢀ
ꢅ = 0.13 mm
T = 120 (2) K
Ê
b = 10.4661 (6) A
1
Ê
c = 9.7703 (5) A
ꢄ = 103.131 (3)ꢀ
3
Ê
V = 902.66 (8) A
Z = 2
Block, colourless
0.26 Â 0.24 Â 0.12 mm
Data collection
Nonius KappaCCD area-detector
diffractometer
' and ! scans
Absorption correction: multi-scan
(SORTAV; Blessing, 1995, 1997)
Tmin = 0.842, Tmax = 0.988
6414 measured re¯ections
2131 independent re¯ections
1848 re¯ections with I > 2ꢆ(I)
Rint = 0.047
ꢀmax = 27.5ꢀ
h = 11 ! 11
k = 12 ! 13
l = 12 ! 12
Re®nement
Re®nement on F2
R[F2 > 2ꢆ(F2)] = 0.038
wR(F2) = 0.094
S = 1.09
2131 re¯ections
248 parameters
H atoms: see below
w = 1/[ꢆ2(Fo2) + (0.0535P)2
+ 0.0412P]
where P = (Fo + 2Fc2)/3
2
(Á/ꢆ)max < 0.001
3
Ê
Áꢇmax = 0.26 e A
3
Ê
0.24 e A
Áꢇmin
=
Table 3
Hydrogen-bond geometry (A, ) for (I).
ꢀ
Ê
DÐHÁ Á ÁA
DÐH
HÁ Á ÁA
DÁ Á ÁA
DÐHÁ Á ÁA
O6ÐH6Á Á ÁO1Wi
0.84
0.91 (5)
0.84 (5)
1.79
2.12 (5)
2.27 (5)
2.592 (3)
2.970 (3)
3.003 (3)
159
155 (4)
146 (4)
O1WÐH1W1Á Á ÁO5
O1WÐH1W2Á Á ÁO10ii
1
2
Symmetry codes: (i) x ‡ 2; y
;
z ‡ 2; (ii) x ‡ 1; y ‡ 12; z ‡ 1.
ꢁ
Acta Cryst. (2005). C61, o711±o714
Baddeley et al. C14H18O11ÁH2O and C14H20O10 o713

organic compounds
Ê
with CÐH = 0.98 and 1.00 A, respectively, for (I) and 0.96 and
Compound (II)
Ê
0.98 A for (II), and re®ned with a riding model, with Uiso(H) =
Crystal data
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
C14H20O10
Mr = 348.30
Orthorhombic, P212121
Ê
a = 9.4830 (8) A
b = 12.6536 (12) A
c = 15.1455 (14) A
Ê
V = 1817.4 (3) A
Z = 4
Dx = 1.273 Mg m
Mo Kꢁ radiation
Cell parameters from 4864
re¯ections
Ê
occupancy factors, with CÐH set to 0.97 A, and they were re®ned
ꢀ = 2.7±24.3ꢀ
ꢅ = 0.11 mm
T = 292 (2) K
1
Ê
Ê
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
3
Block, colourless
0.50 Â 0.50 Â 0.27 mm
Ê
reasonable hydrogen bonding, with OÐH = 0.84 and 0.82 A for (I)
3
and (II), respectively, and re®ned, along with the torsion angle about
the CÐO 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 re®ned with isotropic displacement parameters.
Data collection
Bruker SMART 1000 CCD area
detector diffractometer
' and ! scans
Absorption correction: multi-scan
(SADABS; Sheldrick, 1999)
Tmin = 0.876, Tmax = 0.928
21264 measured re¯ections
3702 independent re¯ections
1921 re¯ections with I > 2ꢆ(I)
Rint = 0.040
ꢀmax = 32.6ꢀ
Data collection: DENZO (Otwinowski & Minor, 1997) and
COLLECT (Nonius, 1998) for (I); SMART (Bruker, 1999) for (II).
Cell re®nement: 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 re®ne
structure: SHELXL97 (Sheldrick, 1997); molecular graphics:
ORTEP-3 for Windows (Farrugia, 1997); software used to prepare
material for publication: SHELXL97 and PLATON (Spek, 2003).
h = 14 ! 10
k = 18 ! 19
l = 22 ! 22
Re®nement
Re®nement on F2
R[F2 > 2ꢆ(F2)] = 0.046
wR(F2) = 0.148
S = 1.00
3702 re¯ections
w = 1/[ꢆ2(Fo2) + (0.0739P)2
+ 0.0408P]
where P = (Fo2 + 2Fc2)/3
(Á/ꢆ)max < 0.001
3
Ê
Áꢇmax = 0.17 e A
3
Ê
0.17 e A
233 parameters
H-atom parameters constrained
Áꢇmin
=
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.
Table 4
Hydrogen-bond geometry (A, ) for (II).
ꢀ
Ê
DÐHÁ Á ÁA
DÐH
HÁ Á ÁA
DÁ Á ÁA
DÐHÁ Á ÁA
O6AÐH6AÁ Á ÁO8i
O6BÐH6BÁ Á ÁO9ii
C8ÐH8BÁ Á ÁO6Biii
0.82
0.82
0.96
2.15
2.10
2.32
2.851 (5)
2.656 (8)
3.280 (7)
144
125
178
Supplementary data for this paper are available from the IUCr electronic
archives (Reference: GG1287). Services for accessing these data are
described at the back of the journal.
Symmetry codes: (i) x ‡ 32; y ‡ 1; z
;
(ii) x ‡ 12; y ‡ 23; z ‡ 1; (iii) x ‡ 32,
1
2
y ‡ 1; z ‡ 12.
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In the absence of any atom with Z > 8, the re®nements 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 con®guration 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 CÐO bond, e.g. C7ÐO1. A similar oscillatory motion
about the C5ÐC6 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.
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In the ®nal stages of re®nement, H atoms of methyl groups and
those attached to tertiary C atoms were placed in calculated positions,
ꢁ
o714 Baddeley et al. C14H18O11ÁH2O and C14H20O10
Acta Cryst. (2005). C61, o711±o714