Structure of cyclic dihydroxyacetone phosphate dimethyl acetal, a cyclic DHAP precursor, in the crystalline state

Article abstract of DOI:10.1016/j.carres.2007.09.011

The six-membered cyclic phosphate diester, 5,5-dimethoxy-2-oxo-1,3,2-dioxaphosphorinane-2-ol, the dimethyl acetal of cyclic dihydroxyacetone phosphate, (MeO)₂cDHAP, was obtained by the isolation of an intermediate in the basic hydrolysis of the

Full text of DOI:10.1016/j.carres.2007.09.011

Available online at www.sciencedirect.com
Carbohydrate Research 343 (2008) 113–131
Structure of cyclic dihydroxyacetone phosphate dimethyl acetal,
a cyclic DHAP precursor, in the crystalline state
´
Katarzyna Slepokura*
Faculty of Chemistry, University of Wrocław, 14 Joliot-Curie St., 50-383 Wrocław, Poland
Received 10 September 2007; received in revised form 25 September 2007; accepted 26 September 2007
Available online 1 October 2007
Abstract—The six-membered cyclic phosphate diester, 5,5-dimethoxy-2-oxo-1,3,2-dioxaphosphorinane-2-ol, the dimethyl acetal of
cyclic dihydroxyacetone phosphate, (MeO)2cDHAP, was obtained by the isolation of an intermediate in the basic hydrolysis of
the cyclic triester derivative. The compound had been isolated in the form of the crystalline cyclohexylammonium (cha) salts:
(cha)[(MeO)2cDHAP]Æ3H2O (5a) and (cha)[(MeO)2cDHAP]ÆH2O (5b), which were then converted into the free acid:
(H5O2)[(MeO)2cDHAP] (5c) and then into a series of different salts: Na[(MeO)2cDHAP]Æ2H2O (5d), K[(MeO)2cDHAP]Æ1.5H2O
(5e), K[(MeO)2cDHAP]Æ0.5H2O (5e0), Ca[(MeO)2cDHAP]2Æ2H2O (5f), CaK[(MeO)2cDHAP]3Æ2H2O (5g) and NH4[(MeO)2cDHAP]
(5h). The synthesis of the compounds, their crystallization and crystal structures determined by X-ray crystallography are described.
The most interesting structural feature observed in 5a–g anions in the crystalline state is the chair conformation of the P/O/C/C/C/O
1,3,2-dioxaphosphorinane ring, which is generally not flattened, in contrast to the deformations often observed in the analogous aryl
´
derivatives (also in (MeO)2cDHAP(Ph); Slepokura, K.; Lis, T. Acta Crystallogr. Sect. C 2004, 60, o315–o317). However, the anion
in crystal 5h is disordered and exists in two conformations, 76% of which is the skew, S, conformation, not observed so far in the
compounds of related structure.
ꢀ 2007 Elsevier Ltd. All rights reserved.
Keywords: Cyclic phosphates; cDHAP; Cyclic dihydroxyacetone phosphate dimethyl acetal; 1,3,2-Dioxaphosphorinane ring; X-ray crystal structure
1. Introduction
acyltransferase and several types of aldolases.1,2 The
DHAP-dependent aldolases have been commonly used
in the synthesis of synthetic sugars and related chiral
The synthesis and structural investigations of cyclic
dihydroxyacetone phosphate (cDHAP) dimethyl acetal
[(MeO)2cDHAP, 5] were undertaken as a continuation
of our previous work on the structural characterization
of the intermediates on the chemical pathway leading
from the simplest ketose, dihydroxyacetone (DHA, 2),
to its phosphate ester, dihydroxyacetone phosphate
(DHAP, 7, Scheme 1).
Me
O
O
Me
O
HO
OH
1
3
O
O
P
DHA
2
O
O
DHAP (7) is one of the most important biochemical
intermediates of high importance for all living cells. It
acts as a substrate for at least 18 different enzymes,
including triosephosphate isomerase, glycerol-3-phos-
phate dehydrogenase, dihydroxyacetone phosphate
(MeO) cDHAP(Ph)
2
4
Me
O
O
Me
P
Me
O
O
O
Me
O
OH
OH
OH
HO
O
HO
O
O
O
8
P
P
OH
O
O
DHAP
7
OH
(MeO) DHAP
2
(MeO) cDHAP
2
5
6
*
Tel.: +48 071 3757338; e-mail addresses: slep@eto.wchuwr.pl;
slep@o2.pl
Scheme 1. Chemical pathway leading from DHA to DHAP.
0008-6215/$ - see front matter ꢀ 2007 Elsevier Ltd. All rights reserved.
doi:10.1016/j.carres.2007.09.011

´
K. Slepokura / Carbohydrate Research 343 (2008) 113–131
114
compounds on a preparative scale. They accept a broad
spectrum of aldehydes, but all of them are very specific
to DHAP. (For a review of the application of DHAP-
dependent aldolases in asymmetric organic synthesis,
see Refs. 3–8.) Dihydroxyacetone phosphate plays a
crucial role in the main metabolic pathways, such as
gluconeogenesis, fructose metabolism, synthesis of tri-
acylglycerols and phospholipids, glycerophosphate shut-
tle and finally in glycolysis.1
The cyclic form of DHAP (cDHAP) became interest-
ing very recently as a new molecule of biological impor-
tance.9 In general, six-membered cyclic phosphate esters
are the constituents of a number of biologically
important molecules, for example, the precursor Z of
molybdenum cofactor (molybdopterin)10 or cyclic
nucleotides, like cAMP. Occurring in living organisms,
small cyclic phosphates of cDHAP-like structure have
simultaneously attracted attention very recently when
their biological activity as signalling molecules had been
suggested. For example, a strong and rapid protein
phosphorylation in cells, induced by 1,3-cyclic glycero-
phosphate and its synthetic analogues (Chart 1) at the
micromolar concentration range, was observed. These
cyclic phosphates were also found to induce neuronal
differentiation in PC12 cells and elevate the state of
differentiation in human breast cancer cells.11 It is to
be mentioned here that cyclic glycerophosphates can
be formed by enzymatic degradation of phospholipids.
1,3-Cyclic glycerophosphate is naturally formed in the
action of phospholipase C on phosphatidyl glycerol,
and it is actually the active residue in cAMP.
There are several popular methods for the chemical
synthesis of six-membered acidic cyclic phosphates, for
example, phosphorylation of the proper 1,3-diol with
POCl3, or phosphorylation of the diol with (ArO)POCl2
and subsequent selective catalytic hydrogenolysis (H2/
Pt–C) of the synthesized neutral triester aryl derivative
(like 4 in Scheme 1; Ar = Ph). It is known that pro-
longed alkaline treatment of the neutral triester precur-
sor also leads to the cyclic diester, but this method is
usually applied for the non-cyclic monoester production
(like 6 in Scheme 1). Ferroni et al., whose synthetic
procedure was the basis of the synthesis presented here,
obtained the linear monoester 6 (stable DHAP precursor)
in a direct 16-hour-long basic hydrolysis of the neutral
compound 4.12 They presume the formation of cyclic
diester 5 in the first stage of this reaction; nevertheless,
the dimethyl acetal of cDHAP was not isolated. When
carrying out this reaction, we have isolated intermediate
5 and found the method of partial basic hydrolysis as
a fast, easy and convenient procedure for the synthesis
of (MeO)2cDHAP, the precursor of cDHAP. The
compound was isolated in the form of its stable cyclo-
hexylammonium (cha) salt trihydrate, (cha)[(MeO)2-
cDHAP]Æ3H2O (5a), and then recrystallized to give
(cha)[(MeO)2cDHAP]ÆH2O (5b), and easily converted
into the free acid: (H5O2)[(MeO)2cDHAP] (5c) and then
into the other salts 5d–h.
Previously, we have reported the crystal and molecular
structures of the series of the compounds occurring on
the first four and the sixth step of the investigated
pathway (1a–c, 2a–c 3, 4 and 6a–e in Scheme 1).13–15
Among other things the results of the structural investi-
gations on the phenyl derivative of the compound
presented here, (MeO)2cDHAP(Ph) (4), have been
published.14 The present paper concerns the synthesis
and the structure of six-membered cyclic phosphate
diester, 5,5-dimethoxy-2-oxo-1,3,2-dioxaphosphorinane-
2-ol, the dimethyl acetal of cyclic dihydroxyacetone
phosphate, (MeO)2cDHAP (5) in the form of the crystal-
line cyclohexylammonium (cha) salts: (cha)[(MeO)2-
cDHAP]Æ3H2O (5a) and (cha)[(MeO)2cDHAP]ÆH2O
(5b), the free acid: (H5O2)[(MeO)2cDHAP] (5c) and
other salts: Na[(MeO)2cDHAP]Æ2H2O (5d), K[(MeO)2-
cDHAP]Æ1.5H2O (5e), K[(MeO)2cDHAP]Æ0.5H2O (5e0),
Ca[(MeO)2cDHAP]2Æ2H2O (5f), CaK[(MeO)2cDHAP]3Æ
2H2O (5g) and NH4[(MeO)2cDHAP] (5h). Thus, the
geometry of the [(MeO)2cDHAP]ꢀ anions occurring in
the nine different salts (with both organic and inorganic
cations), especially the conformation of the P/O/C/C/
C/O 1,3,2-dioxaphosphorinane ring, will be compared
with that of the phenyl derivative, (MeO)2cDHAP(Ph)
(4), and the influence of Ph substituent, the chemical
environment of the anions, as well as the arrangement
in the crystal lattice, will be discussed.
Among the cyclic phosphates with six-membered
rings, two classes of compounds seem to be the most
interesting: 30:50-cyclic nucleotides and cyclic phos-
phates of small organic compounds (Chart 1) of struc-
tures related to that of the (MeO)2cDHAP presented
here. In the cyclic nucleotides, only one from about 20
structures deposited with the Cambridge Structural
Database16 exists in non-chair conformation (but in
skew, S). However, solution studies have shown that
not chair, but just skew conformation is preferred, and
therefore may be important in cellular media.17 Cyclic
phosphates of small compounds structurally related to
the ones presented here in general exist in chair confor-
mation in solid state. Skew or boat conformation has
been never observed in these compounds containing
the tetra-bonded phosphorus atom. However, skew
O
P
H
O
OH
H
O
OH
O
O
O
O
O
O
O
P
O
O
O
O
P
P
O
O
P
O
OH
O
OH
OH
cDHAP
Chart 1. Structures of cyclic dihydroxyacetone phosphate (cDHAP)
along with its analogues: glycerol and 1,3-propandiol cyclic phos-
phates and phenylphosphates.

´
K. Slepokura / Carbohydrate Research 343 (2008) 113–131
115
conformation is often observed in penta-bonded phos-
phorus-containing compounds. Therefore, from the
structural point of view, searches for the small cyclic
phosphates in non-chair conformation may be of great
importance.
unit of which is composed of one [(MeO)2cDHAP]ꢀ ion,
half Ca2+ (located on a twofold axis) and one water
molecule. The water molecule in 5e0 is located on a two-
fold axis. The two crystallographically independent
anions in 5e, as well as three anions in 5g, will be
denoted in the text as 5e-1, 5e-2, 5g-1, 5g-2 and 5g-3.
2. Results and discussion
2.1. Molecular geometry of the anions in 5a–g
Crystals of cyclohexylammonium salts, 5a and 5b, are
composed of [(MeO)2cDHAP]ꢀ monoanions, cyclo-
hexylammonium cations (cha+) and water molecules.
Crystals of 5c and 5h consist of [(MeO)2cDHAP]ꢀ and
H5O2 or NH4 ions. Crystals of 5d–g are built up from
the same [(MeO)2cDHAP]ꢀ anions and water molecules
coordinating to metal cations (Na+, K+ and/or Ca2+).
The asymmetric units of 5a–h consist of the anions
and the other components (cations and water molecules)
in amounts relevant to their molecular formulas, except
for 5e (anion:K:H2O is 2:3:3) and for 5f, the asymmetric
The overall structure of the [(MeO)2cDHAP]ꢀ anions in
crystals 5a–g reveals great similarities (Fig. 1). The six-
membered 1,3,2-dioxaphosphorinane ring (P/O1/C1/
C2/C3/O3) adopts the chair (C) conformation slightly
distorted towards an envelope (E), which is reflected in
the values of dihedral angles between the least-squares
plane through the four central atoms of the ring (O1,
O3, C1 and C3) and the O1/P/O3 and C1/C2/C3 planes
(angles u1 and u2). It is to be noted here that this flatten-
ing of the ring at the P atom is much smaller than that
observed in the molecule of the phenyl derivative,
þ
þ
5a
5g-1,2,3
Figure 1. The molecular structure of the [(MeO)2cDHAP]ꢀ anion in 5a showing the atom numbering scheme along with the comparison of the
geometry of three crystallographically independent anions in 5g (5g-1: thick line, 5g-2,3: thin line; the common reference points are C1, C2, C3).
Displacement ellipsoids are shown at the 40% probability level.
Table 1. The values of u1, u2 and the Cremer–Pople puckering parameters for P/O1/C1/C2/C3/O3 rings in [(MeO)2cDHAP]ꢀ anions in 5a–g along
with the relevant values for the phenyl derivative (MeO)2cDHAP(Ph), 4
u1(ꢁ)
u2(ꢁ)
ju2ꢀu1j (ꢁ)
Cremer–Pople parametersa
˚
Q (A)
H (ꢁ)
U (ꢁ)
(cha)[(MeO)2cDHAP]Æ3H2O (5a)
(cha)[(MeO)2cDHAP]ÆH2O (5b)
(H5O2)[(MeO)2cDHAP] (5c)
Na[(MeO)2cDHAP]Æ2H2O (5d)
K[(MeO)2cDHAP]Æ1.5H2O (5e)
47.3(1)
48.2(1)
45.4(1)
47.5(1)
47.0(2)
47.3(2)
49.9(1)
51.0(1)
40.0(1)
48.4(1)
48.9(2)
—
50.8(1)
50.3(1)
52.5(1)
50.5(2)
53.0(4)
54.4(4)
51.4(2)
49.2(1)
56.0(2)
51.0(3)
50.3(3)
—
3.6
2.1
7.1
3.0
6.0
7.1
1.5
1.8
16.0
2.6
1.4
—
0.573(1)
0.577(1)
0.569(1)
0.576(2)
0.585(4)
0.598(4)
0.598(2)
0.595(2)
0.566(2)
0.584(2)
0.582(2)
0.783(5)
0.66(1)
178.4(1)
177.5(1)
176.3(1)
176.3(2)
176.4(4)
178.3(4)
176.5(2)
174.1(2)
169.9(2)
175.6(2)
176.0(2)
88.1(3)
234(4)
199(2)
321(2)
233(2)
275(6)
309(12)
202(4)
177(2)
356(2)
245(3)
213(3)
90(1)
5e-1
5e-2
K[(MeO)2cDHAP]Æ0.5H2O (5e0)
Ca[(MeO)2cDHAP]2Æ2H2O (5f)
CaK[(MeO)2cDHAP]3Æ2H2O (5g)
5g-1
5g-2
5g-3
Skew
Chair
NH4[(MeO)2cDHAP] (5h)
(MeO)2cDHAP(Ph) (4)
—
35.9(1)
—
51.8(2)
—
15.9
170(1)
167.5(2)
301(6)
349(1)
0.514(2)
a Cremer–Pople parameters are also given for two conformations (skew and chair) of the disordered anion in 5h.

˚
Table 2. Principal interatomic distances (A, ꢁ), valence angles (ꢁ) and torsion angles (ꢁ) in 5a–g and 5h anion in skew (S) conformation (standard deviations in parentheses)
5a 5b 5c 5d 5e 5f
5e0
5g
5h (S)
5e-1
5e-2
5g-1
5g-2
5g-3
P–O1
1.5990(10)
1.5986(9)
1.4888(10)
1.4952(10)
1.446(2)
1.410(2)
1.436(2)
1.413(2)
1.431(2)
1.447(2)
1.530(2)
1.530(2)
1.6068(7)
1.6040(7)
1.4964(8)
1.4833(7)
1.4419(11)
1.4147(11)
1.4358(12)
1.4110(11)
1.4276(12)
1.4420(11)
1.5296(13)
1.5312(12)
1.5913(9)
1.5911(10)
1.5079(9)
1.4952(9)
1.449(2)
1.415(2)
1.440(2)
1.407(2)
1.433(2)
1.454(2)
1.535(2)
1.540(2)
1.616(2)
1.619(2)
1.498(2)
1.474(2)
1.434(2)
1.417(2)
1.433(3)
1.415(2)
1.432(3)
1.441(2)
1.524(3)
1.532(2)
1.624(3)
1.589(3)
1.504(3)
1.468(3)
1.436(5)
1.422(5)
1.425(5)
1.395(5)
1.426(5)
1.453(5)
1.513(6)
1.540(6)
1.627(3)
1.622(3)
1.470(3)
1.490(3)
1.444(5)
1.421(5)
1.424(6)
1.392(5)
1.424(5)
1.440(5)
1.517(6)
1.529(6)
1.625(2)
1.616(2)
1.481(2)
1.481(2)
1.444(3)
1.428(3)
1.430(4)
1.413(3)
1.438(3)
1.441(3)
1.530(4)
1.523(4)
1.6213(10)
1.6008(10)
1.4840(10)
1.4786(10)
1.442(2)
1.418(2)
1.431(2)
1.407(2)
1.445(2)
1.445(2)
1.531(2)
1.535(2)
1.599(2)
1.605(2)
1.487(2)
1.485(2)
1.435(3)
1.408(3)
1.435(3)
1.417(3)
1.439(3)
1.448(3)
1.520(3)
1.524(3)
1.609(2)
1.600(2)
1.493(2)
1.485(2)
1.441(3)
1.421(3)
1.432(3)
1.414(3)
1.428(3)
1.445(3)
1.526(3)
1.521(3)
1.605(2)
1.611(2)
1.490(2)
1.487(2)
1.437(3)
1.412(3)
1.436(3)
1.402(3)
1.438(3)
1.443(3)
1.527(3)
1.522(3)
1.623(6)
P–O3
1.603(2)
1.484(2)
1.476(2)
1.430(8)
1.406(4)
1.403(5)
1.481(6)
1.444(7)
1.441(4)
1.495(6)
1.522(4)
P–O4
P–O5
O1–C1
O21–C2
O21–C4
O22–C2
O22–C5
O3–C3
C1–C2
C2–C3
O1–P–O3
102.58(5)
102.25(4)
104.68(6)
101.04(7)
108.72(7)
109.11(8)
108.76(8)
107.11(7)
120.38(8)
114.6(1)
114.8(2)
116.0(2)
117.2(1)
110.7(2)
111.9(2)
104.2(2)
113.4(2)
111.4(2)
104.8(2)
111.4(2)
110.3(2)
101.4(2)
101.0(2)
100.58(11)
109.48(11)
105.46(11)
109.23(11)
109.11(11)
121.01(12)
114.9(2)
114.8(2)
116.6(2)
114.4(2)
109.3(2)
111.2(2)
104.4(2)
113.9(2)
111.9(2)
104.8(2)
110.8(2)
111.4(2)
100.72(5)
103.02(8)
110.35(9)
107.26(9)
110.55(9)
107.29(9)
117.36(9)
116.9(2)
114.4(2)
115.0(2)
118.8(2)
110.5(2)
112.4(2)
104.0(2)
113.4(2)
113.1(2)
105.3(2)
108.7(2)
108.8(2)
101.77(8)
107.19(9)
108.44(9)
110.65(9)
107.38(9)
119.90(10)
113.8(2)
114.9(2)
115.7(2)
116.1(2)
110.0(2)
111.1(2)
104.1(2)
113.5(2)
111.2(2)
106.7(2)
110.5(2)
111.5(2)
101.47(8)
110.19(9)
106.12(9)
109.44(9)
107.62(9)
120.32(9)
115.1(2)
116.1(2)
115.9(2)
114.9(2)
109.7(2)
112.7(2)
103.6(2)
113.6(2)
111.2(2)
104.7(2)
111.2(2)
111.7(2)
99.8(2)
103.9(2)
115.3(2)
111.4(2)
106.4(2)
118.6(2)
113.3(5)
114.7(3)
113.3(4)
115.6(2)
108.5(4)
109.1(3)
112.6(3)
108.9(4)
112.2(3)
102.1(3)
111.3(3)
109.4(3)
O1–P–O4
110.75(5)
106.15(5)
110.27(5)
108.07(5)
117.86(6)
115.23(8)
115.77(10)
115.47(10)
115.70(7)
110.40(10)
112.43(10)
103.56(9)
113.42(10)
111.25(10)
105.62(10)
110.72(10)
110.92(10)
109.35(4)
107.26(4)
109.53(4)
108.14(4)
119.00(4)
115.24(6)
115.55(7)
115.50(7)
114.97(5)
110.30(7)
112.27(7)
103.99(7)
113.85(7)
110.45(7)
105.40(7)
111.01(7)
111.30(7)
109.05(5)
107.37(5)
109.26(5)
108.42(5)
117.31(6)
115.22(7)
115.44(9)
115.66(9)
115.86(7)
109.59(8)
112.74(11)
103.70(8)
113.63(9)
111.03(9)
105.31(9)
110.57(10)
110.62(9)
108.4(2)
108.2(2)
109.2(2)
107.7(2)
120.3(2)
113.9(3)
115.8(3)
115.9(4)
118.2(3)
110.1(4)
112.9(3)
103.6(4)
114.6(4)
110.5(4)
104.4(4)
111.0(4)
108.6(4)
111.2(2)
107.2(2)
111.1(2)
105.4(2)
119.3(2)
114.2(3)
115.6(4)
116.2(3)
116.5(3)
110.3(4)
112.4(4)
104.1(4)
114.1(4)
110.8(4)
105.7(4)
109.8(4)
109.2(4)
108.47(6)
107.64(5)
109.50(5)
108.32(6)
120.40(6)
114.30(8)
116.21(11)
115.08(11)
114.42(8)
111.15(11)
112.05(10)
103.25(10)
114.19(11)
110.90(11)
105.75(11)
110.84(11)
110.91(11)
O1–P–O5
O3–P–O4
O3–P–O5
O4–P–O5
P–O1–C1
C2–O21–C4
C2–O22–C5
P–O3–C3
O1–C1–C2
O21–C2–O22
O21–C2–C1
O22–C2–C1
O21–C2–C3
O22–C2–C3
C1–C2–C3
O3–C3–C2
O3–P–O1–C1
55.00(9)
ꢀ62.66(9)
168.30(8)
55.98(6)
ꢀ60.04(7)
169.63(6)
ꢀ54.90(6)
61.00(6)
53.19(8)
ꢀ63.64(9)
168.29(8)
55.9(2)
ꢀ58.4(2)
168.6(2)
ꢀ54.1(2)
60.2(2)
55.3(3)
ꢀ59.6(3)
168.3(3)
ꢀ53.8(3)
60.5(3)
54.4(3)
ꢀ63.5(4)
164.5(3)
ꢀ54.3(3)
63.6(3)
58.2(2)
ꢀ56.7(2)
171.6(2)
ꢀ56.3(2)
58.8(2)
58.40(9)
ꢀ56.52(10)
171.72(8)
46.6(2)
ꢀ71.4(2)
159.6(2)
ꢀ46.6(2)
71.3(2)
57.2(2)
ꢀ59.0(2)
170.2(2)
ꢀ53.9(2)
59.7(2)
57.6(2)
ꢀ58.3(2)
170.0(2)
ꢀ54.9(2)
61.5(2)
ꢀ37.0(4)
ꢀ152.2(4)
76.4(5)
O4–P–O1–C1
O5–P–O1–C1
O1–P–O3–C3
ꢀ53.96(9)
64.04(10)
ꢀ51.04(8)
65.65(9)
ꢀ58.79(9)
55.35(10)
ꢀ32.5(3)
76.7(2)
O4–P–O3–C3
O5–P–O3–C3
ꢀ165.84(8)
ꢀ59.69(12)
57.70(12)
ꢀ167.89(6)
ꢀ59.58(8)
58.24(8)
ꢀ165.40(8)
ꢀ59.58(11)
55.61(11)
ꢀ168.3(2)
ꢀ61.8(2)
56.4(2)
ꢀ167.2(3)
ꢀ62.7(4)
56.7(5)
ꢀ165.8(3)
ꢀ62.1(4)
59.8(4)
ꢀ166.9(2)
ꢀ61.7(3)
59.8(3)
ꢀ171.60(9)
ꢀ59.96(12)
60.83(13)
ꢀ159.6(2)
ꢀ58.7(2)
56.8(2)
ꢀ167.7(2)
ꢀ63.0(2)
56.3(2)
ꢀ166.1(2)
ꢀ61.4(2)
57.5(2)
ꢀ152.7(2)
74.2(6)
P–O1–C1–C2
P–O3–C3–C2
68.1(3)
C4–O21–C2–O22
C4–O21–C2–C1
C4–O21–C2–C3
C5–O22–C2–O21
C5–O22–C2–C1
C5–O22–C2–C3
O1–C1–C2–O21
O1–C1–C2–O22
O1–C1–C2–C3
O3–C3–C2–O21
O3–C3–C2–O22
O3–C3–C2–C1
53.82(15)
47.45(10)
170.98(7)
ꢀ69.87(9)
66.67(10)
ꢀ51.14(10)
ꢀ173.04(7)
174.32(7)
ꢀ63.20(9)
55.54(9)
58.08(13)
65.6(2)
56.8(5)
56.8(5)
59.2(3)
56.22(15)
54.3(3)
59.9(3)
53.7(3)
55.0(5)
176.63(11)
ꢀ64.41(14)
63.95(13)
ꢀ178.58(11)
ꢀ59.82(14)
60.63(14)
ꢀ171.5(2)
ꢀ51.3(2)
61.9(2)
ꢀ178.7(4)
ꢀ59.8(5)
67.9(5)
ꢀ179.2(4)
ꢀ61.3(5)
65.0(5)
ꢀ177.5(2)
ꢀ57.6(3)
69.8(3)
179.55(12)
ꢀ61.69(15)
56.39(15)
177.4(2)
ꢀ64.9(3)
69.1(2)
ꢀ177.6(2)
ꢀ58.7(3)
68.3(2)
177.0(2)
ꢀ63.5(3)
64.4(3)
176.1(4)
ꢀ57.4(4)
61.3(5)
ꢀ53.12(14)
ꢀ174.54(10)
175.75(10)
ꢀ62.10(13)
56.42(14)
ꢀ57.00(15)
ꢀ178.15(12)
177.69(9)
ꢀ55.6(2)
ꢀ177.3(2)
177.4(2)
ꢀ60.7(2)
57.2(2)
ꢀ50.4(5)
ꢀ172.0(4)
178.9(4)
ꢀ57.6(5)
60.3(5)
ꢀ53.2(5)
ꢀ174.0(4)
179.6(3)
ꢀ57.5(5)
60.9(5)
ꢀ47.9(3)
ꢀ169.2(2)
177.2(2)
ꢀ61.4(3)
56.5(3)
ꢀ60.55(15)
177.32(11)
172.88(10)
ꢀ65.21(14)
54.09(14)
ꢀ48.5(3)
ꢀ167.3(2)
ꢀ176.5(2)
ꢀ54.0(3)
62.8(2)
ꢀ48.6(3)
ꢀ170.5(2)
177.5(2)
ꢀ61.6(3)
58.1(3)
ꢀ53.1(3)
ꢀ174.6(2)
175.5(2)
ꢀ61.9(3)
55.9(3)
ꢀ62.0(5)
ꢀ179.8(4)
91.0(5)
ꢀ59.56(12)
58.60(11)
ꢀ147.9(4)
ꢀ36.1(6)
ꢀ157.1(3)
86.3(3)
ꢀ170.03(9)
67.70(12)
ꢀ170.07(6)
68.45(8)
ꢀ171.31(9)
66.36(12)
ꢀ169.6(2)
69.2(2)
ꢀ169.7(3)
68.5(4)
ꢀ173.2(4)
64.7(5)
ꢀ172.4(2)
67.0(3)
ꢀ168.30(10)
70.02(13)
ꢀ175.6(2)
61.2(2)
ꢀ169.4(2)
69.3(2)
ꢀ169.6(2)
68.4(2)
ꢀ55.45(13)
ꢀ55.26(9)
ꢀ56.77(11)
ꢀ53.7(2)
ꢀ55.4(5)
ꢀ58.8(5)
ꢀ56.3(3)
ꢀ54.23(14)
ꢀ60.6(2)
ꢀ54.4(3)
ꢀ54.7(3)
ꢀ29.8(5)

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K. Slepokura / Carbohydrate Research 343 (2008) 113–131
117
(MeO)2cDHAP(Ph).14 The values of u1 and u2, along
with the Cremer–Pople puckering parameters for the
[(MeO)2cDHAP]ꢀ anions in crystals 5a–g, as well as
for the phenyl derivative (4), are given in Table 1.
Values of ju2 ꢀ u1j given in Table 1 clearly show that
the flattening of the dioxaphosphorinane ring is negligi-
ble in almost all of the [(MeO)2cDHAP]ꢀ anions in
5a–g, and the conformation of the rings may be
described as close to an ideal chair. Only in one of three
crystallographically independent anions in CaK[(MeO)2-
cDHAP]3Æ2H2O, 5g-1 (Fig. 1), the deformation of P/O1/
C1/C2/C3/O3 ring is more distinct and is comparable to
that observed in the phenyl derivative (MeO)2c-
DHAP(Ph) (4). However, it is probable that the differ-
ences in the geometry of 5g-1,2,3 result from the close
chemical environment of the respective anions, which
will be discussed later.
moiety, (MeO)2DHA–, seems to be very rigid, and its
conformation (described as deformed swastika-like) is
independent of phosphorylation, the ionization state of
the inserted phosphate group, or its additional substitu-
tion. It is very likely that such conformation of the
dihydroxyacetone acetal moiety in the non-cyclic com-
pounds is determined and stabilized by the generalized
anomeric effect, whose role in carbohydrate chemistry
is well known.
The dihydroxyacetone acetal moiety in the cyclic com-
pounds 4 and 5 is forced by the cyclization, and there-
fore it is somewhat different than in the non-cyclic
analogues. However, some common features with com-
pounds 3 and 6 are observed: the relevant C4–O21–C2–
O22 and C5–O22–C2–O21 torsion angles reveal the
synclinal (nearly gauche) orientation of the methyl
groups (C4 and C5) in relation to the acetal O22 and
O21 oxygen atoms. Similarly, as was observed in the
structures of compounds 3, 4 and 6, the O21–C2–C1
and O22–C2–C3 bond angles are much smaller than
the other angles with their vertex on the acetal C2 atom.
The selected geometrical parameters for the
[(MeO)2cDHAP]ꢀ anions in 5a–h are given in Table 2.
In the phosphate group, a deformation from the ideal
tetrahedral shape is observed, especially in the endo-
cyclic O1–P–O3 and exocyclic O4–P–O5 bond angles,
which are, respectively, the smallest (about 102ꢁ on aver-
age) and the largest (about 119ꢁ) from all the O–P–O
angles. On the whole, the differences in the values of
endo- and exocyclic O–P–O angles are correlated with
the differences in the P–O bond lengths. In all the pre-
sented anions, endocyclic ester P–O bonds (P–O1 and
2.2. Molecular geometry of the anions in 5h
The [(MeO)2cDHAP]ꢀ anion in the ammonium salt 5h is
disordered into two positions with two different confor-
mations of the P/O1/C1/C2/C3/O3 ring, the skew, S,
and the chair, C, which are shown in Figure 2 and in
Table 1. Site occupation factors determined for the
two conformations (0.762(9) for S and 0.238(9) for C)
reveal that as much as 76% of the anions in the crystal
of ammonium salt exist in S conformation, which has
not been observed so far in the six-membered cyclic
phosphates of small compounds structurally related
with that presented here. It is to mention here that C4
and C5 methyl groups in the higher occupied S position
of the anion are in synclinal orientation in relation to the
acetal O22 and O21 oxygen atoms, just like it was
observed in the previously mentioned compounds 3, 4,
5a–g and 6.
˚
P–O3) are over 0.1 A longer than the exocyclic P–O4
and P–O5 bonds.
The geometry of the dihydroxyacetone acetal moiety
was analyzed in detail for the linear, non-cyclic com-
pounds: dihydroxyacetone dimethyl acetal, (MeO)2-
DHA (3)13 and the series of five different salts of its
phosphate and phenylphosphate derivatives, (MeO)2-
DHAP and (MeO)2DHAP(Ph) (6).15 The crystal struc-
ture of the cyclic compound, a phenyl derivative of the
compound presented here, (MeO)2cDHAP(Ph) (4),
was also reported.14 It was shown that in the non-cyclic
compounds 3 and 6, the 2,2-dimethoxy-1,3-propandiol
76% in skew conformation
24% in chair conformation
Figure 2. The molecular structure of the disordered [(MeO)2cDHAP]ꢀ anion in 5h showing the atom numbering schemes of the separate anions, with
different skew, S (full line; s.o.f. = 0.762(9)) and chair, C (open line; s.o.f. = 0.238(9)) conformations. The two anions occupy the same site in the
asymmetric unit of 5h in an approximate 3:1 ratio. Displacement ellipsoids are shown at the 20% probability level.

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K. Slepokura / Carbohydrate Research 343 (2008) 113–131
118
2.3. Crystal packing and intermolecular interactions in
the crystals of cyclohexylammonium salts: (cha)[(MeO)2-
cDHAP]Æ3H2O (5a) and (cha)[(MeO)2cDHAP]ÆH2O
(5b), oxonium (H5O2)[(MeO)2cDHAP] (5c) and
ammonium NH4[(MeO)2cDHAP] (5h)
hydrogen bonds of the N–Hꢁ ꢁ ꢁO type, which, in combi-
nation with O–Hꢁ ꢁ ꢁO interactions, build the crystal
lattices. Water molecules, NH4 or cha+ cations act as
þ
donors of these hydrogen bonds, and the role of accep-
tors is played mainly by exocyclic phosphate oxygen
atoms O4 and O5, rarely by water molecules and only
once by endocyclic phosphate oxygen atom O1. Addi-
tionally, the crystal structures of 5a–c and 5h are also
stabilized by C–Hꢁ ꢁ ꢁO interactions. The geometrical
parameters of the proposed hydrogen bonds and close
contacts are given in Table 3.
The crystal structure of oxonium salt 5c is stabilized
mainly by the network of O–Hꢁ ꢁ ꢁO hydrogen bonds.
The crystal packing of anhydrous ammonium salt 5h is
dominated by N–Hꢁ ꢁ ꢁO contacts. In cyclohexylammo-
nium salts 5a and 5b an important role is played by
˚
Table 3. Geometry of proposed hydrogen bonds and close C–Hꢁ ꢁ ꢁO contacts for 5a–c and 5h (A, ꢁ)
˚
˚
˚
D–Hꢁ ꢁ ꢁA
D–H (A)
Hꢁ ꢁ ꢁA (A)
Dꢁ ꢁ ꢁA (A)
D–Hꢁ ꢁ ꢁA (ꢁ)
(cha)[(MeO)2cDHAP]Æ3H2O (5a)
N–H1Nꢁ ꢁ ꢁO1
0.96(2)
0.96(2)
0.87(2)
0.92(2)
0.86(3)
0.84(3)
0.87(3)
0.89(3)
0.88(3)
0.87(3)
0.99(2)
0.98(2)
0.99(2)
0.97(2)
0.97(2)
0.98(2)
1.00(2)
2.55(2)
1.94(2)
1.98(2)
1.93(2)
1.90(3)
2.00(3)
1.91(3)
1.94(3)
1.88(3)
1.86(3)
2.71(2)
2.50(2)
2.69(2)
2.47(2)
2.54(2)
2.67(2)
2.67(2)
3.097(2)
2.890(2)
2.829(2)
2.856(2)
2.755(2)
2.830(2)
2.773(2)
2.814(2)
2.748(2)
2.730(2)
3.238(2)
3.473(2)
3.419(2)
3.338(2)
3.503(2)
3.643(2)
3.489(2)
116(2)
173(2)
167(2)
175(2)
177(2)
171(2)
169(2)
165(2)
170(2)
176(2)
114(2)
175(2)
130(2)
150(2)
170(2)
175(2)
139(2)
N–H1Nꢁ ꢁ ꢁO5
N–H2Nꢁ ꢁ ꢁO1Wi
N–H3Nꢁ ꢁ ꢁO5ii
O1W–H1Wꢁ ꢁ ꢁO4
O1W–H2Wꢁ ꢁ ꢁO3Wiii
O2W–H3Wꢁ ꢁ ꢁO3Wiv
O2W–H4Wꢁ ꢁ ꢁO5
O3W–H5Wꢁ ꢁ ꢁO4
O3W–H6Wꢁ ꢁ ꢁO2Wv
C1–H1Bꢁ ꢁ ꢁO2Wvi
C3–H3Bꢁ ꢁ ꢁO22vii
C4–H4Aꢁ ꢁ ꢁO3vii
C4–H4Bꢁ ꢁ ꢁO21viii
C5–H5Cꢁ ꢁ ꢁO1Wi
C11–H11ꢁ ꢁ ꢁO3Wix
C12–H12Bꢁ ꢁ ꢁO3i
(cha)[(MeO)2cDHAP]ÆH2O (5b)
N–H1Nꢁ ꢁ ꢁO4vii
0.91(2)
0.95(2)
0.94(2)
0.87(2)
0.83(2)
0.96(2)
0.97(2)
0.97(2)
0.97(2)
1.95(2)
1.82(2)
1.86(2)
1.90(2)
1.97(2)
2.59(2)
2.69(2)
2.72(2)
2.58(2)
2.830(2)
2.765(2)
2.774(2)
2.764(2)
2.799(2)
3.548(2)
3.576(2)
3.282(2)
3.348(2)
162(2)
172(2)
164(2)
175(2)
174(2)
172(1)
152(2)
117(1)
137(1)
N–H2Nꢁ ꢁ ꢁO5
N–H3Nꢁ ꢁ ꢁOWx
OW–H1Wꢁ ꢁ ꢁO5
OW–H2Wꢁ ꢁ ꢁO4x
C3–H3Bꢁ ꢁ ꢁO22viii
C4–H4Bꢁ ꢁ ꢁO22viii
C5–H5Bꢁ ꢁ ꢁO21x
C11–H11ꢁ ꢁ ꢁOWxi
(H5O2)[(MeO)2cDHAP] (5c)
O2Wꢁ ꢁ ꢁH3Wꢁ ꢁ ꢁO1W
O1W–H1Wꢁ ꢁ ꢁO5xii
O1W–H2Wꢁ ꢁ ꢁO4
1.21(3)
0.89(2)
0.91(3)
0.84(3)
0.95(2)
0.91(2)
0.93(2)
1.23(3)
1.72(2)
1.69(3)
1.79(3)
1.63(2)
2.58(2)
2.73(2)
2.437(2)
2.602(2)
2.608(2)
2.616(2)
2.580(2)
3.417(2)
3.653(2)
173(3)
176(2)
177(3)
167(3)
178(3)
154(2)
169(2)
O2W–H4Wꢁ ꢁ ꢁO5iv
O2W–H5Wꢁ ꢁ ꢁO4xiii
C3–H3Bꢁ ꢁ ꢁO21xiv
C4–H4Bꢁ ꢁ ꢁO2Wxv
NH4[(MeO)2cDHAP] (5h)
N–H1Nꢁ ꢁ ꢁO4
1.02(5)
1.11(4)
0.98(5)
0.94(5)
0.98
1.79(5)
1.70(4)
1.90(5)
1.96(5)
2.68
2.785(4)
2.806(4)
2.826(4)
2.878(4)
3.641(6)
3.61(2)
163(4)
173(3)
158(4)
163(4)
168
N–H2Nꢁ ꢁ ꢁO5ii
N–H3Nꢁ ꢁ ꢁO5xvi
N–H4Nꢁ ꢁ ꢁO4xvii
C1–H1Bꢁ ꢁ ꢁO21xviii
C10–H10Aꢁ ꢁ ꢁO21xviii
0.98
2.63
172
Symmetry codes: (i) x, y, z ꢀ 1; (ii) x, ꢀy + 1/2, z ꢀ 1/2; (iii) x, ꢀy + 1/2, z + 1/2; (iv) x ꢀ 1, y, z; (v) x + 1, ꢀy + 1/2, z + 1/2; (vi) x + 1, y, z; (vii)
ꢀx + 1, ꢀy + 1, ꢀz + 1; (viii) ꢀx + 2, ꢀy + 1, ꢀz + 1; (ix) x ꢀ 1, ꢀy + 1/2, z ꢀ 1/2; (x) x, ꢀy + 3/2, z + 1/2; (xi) ꢀx + 1, y ꢀ 1/2, ꢀz+3/2; (xii)
x ꢀ 1/2, ꢀy + 1, z; (xiii) x ꢀ 1/2, ꢀy + 2, z; (xiv) x + 1/2, ꢀy + 2, z; (xv) ꢀx + 1/2, y, z + 1/2; (xvi) ꢀx + 1, y + 1/2, ꢀz + 1/2; (xvii) ꢀx + 1, y ꢀ 1/2,
ꢀz + 1/2; (xviii) ꢀx, ꢀy + 1, ꢀz + 1.

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K. Slepokura / Carbohydrate Research 343 (2008) 113–131
119
The overall packing schemes in the crystal lattices of
hydrated cyclohexylammonium salts 5a and 5b are
similar. The cations and anions are arranged in a way
leading to the aggregation of their hydrophilic and
hydrophobic groups into distinct regions in the crystals.
The hydrophilic parts of the ions are linked by the
N–Hꢁ ꢁ ꢁO hydrogen bonds, which is illustrated in Figure
3. The voids formed between the organic cations and
anions are filled by the water molecules, which partici-
pate in hydrogen bonds of cha+ꢁ ꢁ ꢁH2Oꢁ ꢁ ꢁanion (and
anionꢁ ꢁ ꢁH2Oꢁ ꢁ ꢁanion in 5b) type. The water molecules
in 5a are involved in additional H2Oꢁ ꢁ ꢁH2O and
H2Oꢁ ꢁ ꢁanion interactions formed between four adjacent
water molecules and one phosphate O4 atom (Fig. 3).
This gives rise to R35ð10Þ motifs linking the adjacent
[(MeO)2cDHAP]ꢀ anions. Each of such rings is
connected by the hydrogen bonds with three different
anions.
The crystals of oxonium (5c) and ammonium (5h) salts
have layered architectures, and their structures are stabi-
lized mainly by O–Hꢁ ꢁ ꢁO (in 5c) and N–Hꢁ ꢁ ꢁO (in 5h)
hydrogen bonds. The H+ dissociated from the cyclic
phosphate group is involved in Zundel ion formation,
+
H5O ([H2Oꢁ ꢁ ꢁHꢁ ꢁ ꢁOH2] ),18 with both H2Oꢁ ꢁ ꢁH+ dis-
þ
2
˚
tances equal and amounting to 1.21(3) i 1.23(3) A, and
with Oꢁ ꢁ ꢁO distance being characteristic for a very strong
þ
˚
hydrogen bond (2.437(2) A). H5O2 cations are located
close to the phosphate groups of [(MeO)2cDHAP]ꢀ
anions. The hydrogen bonds of O–Hꢁ ꢁ ꢁO type formed
between the Zundel cations and phosphate exocyclic
O4 and O5 atoms give rise to layers parallel to (001)
plane in the 5c crystal, which is shown in Figure 4. The
5a
5b
Figure 3. Arrangement of [(MeO)2cDHAP]ꢀ anions, cha+ cations and water molecules in the cyclohexylammonium salts crystals 5a and 5b.
O–Hꢁ ꢁ ꢁO and N–Hꢁ ꢁ ꢁO hydrogen bonds are drawn with dashed lines, C–Hꢁ ꢁ ꢁO with dotted line. The cha+ are shown with thin line for clarity.
Symmetry codes are listed in Table 3.
a
b
c
0
a
Figure 4. The layers in 5c formed by the H5O and [(MeO)2cDHAP]ꢀ ions joined to each other by the O–Hꢁ ꢁ ꢁO and C–Hꢁ ꢁ ꢁO hydrogen bonds
þ
2
(dashed lines). Viewed down the b-axis (a) and c-axis (b; only the phosphate groups of the anions are shown for clarity). Symmetry codes are given in
Table 3.

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K. Slepokura / Carbohydrate Research 343 (2008) 113–131
120
adjacent anions within the layer are additionally linked
to each other by C3–H3Bꢁ ꢁ ꢁO21xiv contacts, which also
stabilize the layer structure (Fig. 4, Table 3). Very weak
C–Hꢁ ꢁ ꢁO interactions may also be observed between the
from the adjacent (C4–H4Bꢁ ꢁ ꢁO2Wxv).
þ
methyl groups from one layer and the H5O2 cations
a
b
Figure 5. The crystal packing in 5h: four symmetry-related ammonium cations in the close environment of the [(MeO)2cDHAP]ꢀ anion (a), and the
fragment of the double-layer formed by the cations and anions joined with each other by the N–Hꢁ ꢁ ꢁO hydrogen bonds (b). Only anions in skew
conformation (s.o.f. = 0.762(9)) are shown. Symmetry codes are listed in Table 3.
˚
˚
Table 4. Coordination spheres of the sodium, potassium and calcium ions in 5d–g (M–O, A) along with the shortest Mꢁ ꢁ ꢁM distances (A)
Na[(MeO)2cDHAP]Æ2H2O (5d)
Na–O5
2.428(2)
2.360(2)
2.406(2)
2.406(2)
Na–O1Wii
Na–O2Wi
Naꢁ ꢁ ꢁNai,ii
2.436(2)
2.499(2)
3.282(1)
Na–O5i
Na–O1W
Na–O2W
K[(MeO)2cDHAP]Æ1.5H2O (5e)
K1–O221
K1–O31
2.978(3)
2.830(4)
3.323(3)
2.914(3)
2.847(3)
2.665(3)
2.732(5)
2.795(4)
4.429(2)
K2–O51
K2–O222
K2–O32
K2–O42v
K2–O52v
K2–O1W
K2–O2W
K2ꢁ ꢁ ꢁK1iii
K2ꢁ ꢁ ꢁK1vi
2.641(3)
2.859(3)
2.967(3)
3.026(3)
2.847(3)
2.821(4)
2.724(4)
4.117(2)
4.143(2)
K1–O51
K1–O51iii
K1–O42iv
K1–O52v
K1–O1Wiii
K1–O2Wv
K1ꢁ ꢁ ꢁK2
K[(MeO)2cDHAP]Æ0.5H2O (5e0)
K–O1
K–O5
K–O4vii
K–O5viii
K–O5iii
2.836(2)
2.850(2)
2.633(2)
2.705(2)
2.768(2)
K–OW
2.854(2)
3.694(2)
4.154(2)
4.844(2)
Kꢁ ꢁ ꢁKiii
Kꢁ ꢁ ꢁKix
Kꢁ ꢁ ꢁKviii,x
Ca[(MeO)2cDHAP]2Æ2H2O (5f)
Ca–O4,O4xi
Ca–O5viii,xii
2.259(1)
2.337(1)
Ca–OW,OWxi
Caꢁ ꢁ ꢁCaiii,xii
2.383(1)
5.643(1)
CaK[(MeO)2cDHAP]3Æ2H2O (5g)
Ca–O41
Ca–O51xiii
Ca–O42
Ca–O52xiv
Ca–O53
Ca–O1W
Caꢁ ꢁ ꢁK
2.325(2)
2.330(2)
2.309(2)
2.354(2)
2.346(2)
2.353(2)
4.040(2)
3.994(1)
K–O221xiii
K–O31xiii
K–O41
2.807(2)
2.784(2)
3.045(2)
2.731(2)
3.135(2)
2.732(2)
3.093(2)
2.734(2)
K–O51
K–O52xv
K–O13
K–O53
K–O2W
Caꢁ ꢁ ꢁKxiii
Symmetry codes: (i) ꢀx + 1/2, y + 1/2, ꢀz + 1/2; (ii) ꢀx + 1/2, y ꢀ 1/2, ꢀz + 1/2; (iii) ꢀx + 1, ꢀy + 1, ꢀz + 1; (iv) x, y, z ꢀ 1; (v) x, ꢀy + 3/2, z ꢀ 1/2;
(vi) x, ꢀy + 3/2, z + 1/2; (vii) x, y ꢀ 1, z; (viii) x, ꢀy + 1, z ꢀ 1/2; (ix) ꢀx + 1, y, ꢀz + 1/2; (x) x, ꢀy + 1, z + 1/2; (xi) ꢀx + 1, y, ꢀz + 3/2; (xii) ꢀx + 1,
ꢀy + 1, ꢀz + 2; (xiii) ꢀx + 3/2, y ꢀ 1/2, ꢀz + 1/2; (xiv) ꢀx + 2, ꢀy ꢀ 1, ꢀz + 1; (xv) x ꢀ 1/2, ꢀy ꢀ 1/2, z ꢀ 1/2.

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121
In the crystal of ammonium salt (5h), the double
2.4. The environment of the [(MeO)2cDHAP]ꢀ ions and
layers parallel to the (100) plane are observed. The
double layers are formed by NH4 cations and the
their arrangement in the crystals of the hydrated sodium,
potassium, calcium and calcium–potassium salts:
Na[(MeO)2cDHAP]Æ2H2O (5d), K[(MeO)2cDHAP]Æ
1.5H2O (5e), K[(MeO)2cDHAP]Æ0.5H2O (5e0),
Ca[(MeO)2cDHAP]2Æ2H2O (5f) and CaK[(MeO)2cD-
HAP]3Æ2H2O (5g)
þ
organic anions linked with each other by the N–Hꢁ ꢁ ꢁO
hydrogen bonds (Fig. 5, Table 3). The phosphate
exocyclic O4 and O5 atoms of each [(MeO)2cDHAP]ꢀ
anion act as acceptors of two N–Hꢁ ꢁ ꢁO contacts from
two, symmetry-related ammonium cations. Therefore,
there are four NH4þ cations located in the close environ-
ment of each anion.
The characteristics of the crystal packing diagrams of
5d–g are double layers built up from the organic anions
˚
Table 5. Geometry of proposed hydrogen bonds and close C–Hꢁ ꢁ ꢁO contacts for 5d–g (A, ꢁ)
˚
˚
˚
D–Hꢁ ꢁ ꢁA
D–H (A)
Hꢁ ꢁ ꢁA (A)
Dꢁ ꢁ ꢁA (A)
D–Hꢁ ꢁ ꢁA (ꢁ)
Na[(MeO)2cDHAP]Æ2H2O (5d)
O1W–H1Wꢁ ꢁ ꢁO4viii
O1W–H2Wꢁ ꢁ ꢁO22
O2W–H3Wꢁ ꢁ ꢁO3ii
O2W–H4Wꢁ ꢁ ꢁO4xvi
C1–H1Aꢁ ꢁ ꢁO21iii
0.81(4)
0.73(3)
0.82(3)
0.85(3)
0.97(2)
0.96(2)
0.95(2)
0.91(3)
1.97(4)
2.21(3)
2.10(3)
1.94(3)
2.58(2)
2.65(2)
2.56(2)
2.69(3)
2.761(2)
2.941(2)
2.891(2)
2.789(2)
3.440(2)
3.407(2)
3.497(3)
3.449(3)
165(3)
174(3)
162(3)
174(3)
149(2)
136(2)
169(2)
142(3)
C3–H3Aꢁ ꢁ ꢁO1Wx
C3–H3Bꢁ ꢁ ꢁO4xvii
C4–H4Cꢁ ꢁ ꢁO4xvii
K[(MeO)2cDHAP]Æ1.5H2O (5e)
O1W–H1Wꢁ ꢁ ꢁO3Wxviii
O1W–H2Wꢁ ꢁ ꢁO32xii
O2W–H3Wꢁ ꢁ ꢁO41xviii
O2W–H4Wꢁ ꢁ ꢁO3Wiii
O3W–H5Wꢁ ꢁ ꢁO52xix
O3W–H6Wꢁ ꢁ ꢁO41
0.87(6)
0.81(5)
0.69(5)
1.01(5)
0.83(5)
0.81(5)
0.99
0.98
0.98
0.98
1.93(6)
2.48(5)
2.10(5)
1.82(5)
1.97(5)
1.92(5)
2.54
2.48
2.52
2.54
2.781(6)
3.116(5)
2.785(4)
2.822(6)
2.787(5)
2.705(5)
3.519(6)
3.437(6)
3.287(6)
3.213(6)
166(6)
136(4)
174(7)
168(5)
165(5)
164(6)
170
166
135
126
C11–H11Aꢁ ꢁ ꢁO212xx
C41–H41Cꢁ ꢁ ꢁO41xxi
C51–H51Bꢁ ꢁ ꢁO42iv
C52–H52Bꢁ ꢁ ꢁO11
K[(MeO)2cDHAP]Æ0.5H2O (5e0)
OW–H1Wꢁ ꢁ ꢁO4iii
0.80(3)
0.99
0.99
0.98
0.98
2.02(3)
2.53
2.64
2.68
2.65
2.816(2)
3.472(4)
3.390(4)
3.346(4)
3.524(4)
169(4)
160
133
125
148
C1–H1Aꢁ ꢁ ꢁO22viii
C3–H3Bꢁ ꢁ ꢁO21xxii
C5–H5Aꢁ ꢁ ꢁO22viii
C5–H5Cꢁ ꢁ ꢁO3viii
Ca[(MeO)2cDHAP]2Æ2H2O (5f)
OW–H1Wꢁ ꢁ ꢁO21x
0.84(2)
0.82(2)
0.92(2)
0.99(2)
0.99(2)
2.00(2)
1.99(2)
2.60(2)
2.50(2)
2.62(2)
2.836(2)
2.794(2)
3.523(2)
3.230(2)
3.519(2)
175(2)
166(2)
176(2)
130(2)
151(2)
OW–H2Wꢁ ꢁ ꢁO1xvii
C3–H3Bꢁ ꢁ ꢁO22xxiii
C5–H5Cꢁ ꢁ ꢁO5xvi
C5–H5Cꢁ ꢁ ꢁOWvii
CaK[(MeO)2cDHAP]3Æ2H2O (5g)
O1W–H1Wꢁ ꢁ ꢁO43
0.77(3)
0.83(3)
0.76(3)
0.92(3)
0.97(3)
1.00(3)
0.97(2)
1.00(2)
0.95(3)
0.96(3)
2.07(3)
1.92(3)
2.29(3)
1.94(3)
2.48(2)
2.61(3)
2.42(3)
2.47(3)
2.56(3)
2.71(3)
2.793(3)
2.734(3)
2.981(3)
2.835(3)
3.049(3)
3.605(4)
3.358(3)
3.409(3)
3.298(3)
3.437(4)
157(3)
166(3)
152(3)
163(3)
118(2)
172(2)
162(2)
156(2)
134(2)
133(2)
O1W–H2Wꢁ ꢁ ꢁO2Wxxiv
O2W–H3Wꢁ ꢁ ꢁO42xxv
O2W–H4Wꢁ ꢁ ꢁO43xiii
C11–H11Aꢁ ꢁ ꢁO213xiii
C41–H41Bꢁ ꢁ ꢁO43xxvi
C51–H51Aꢁ ꢁ ꢁO223xxv
C32–H32Aꢁ ꢁ ꢁO53
C43–H43Cꢁ ꢁ ꢁO223xxvii
C53–H53Bꢁ ꢁ ꢁO32xv
Symmetry codes: (ii) ꢀx + 1/2, y ꢀ 1/2, ꢀz + 1/2; (iii) ꢀx + 1, ꢀy + 1, ꢀz + 1; (iv) x, y, z ꢀ 1; (vii) x, y ꢀ 1, z; (viii) x, ꢀy + 1, z ꢀ 1/2; (x) x, ꢀy + 1,
z + 1/2; (xii) ꢀx + 1, ꢀy + 1, ꢀz + 2; (xiii) ꢀx + 3/2, y ꢀ 1/2, ꢀz + 1/2; (xv) x ꢀ 1/2, ꢀy ꢀ 1/2, z ꢀ 1/2; (xvi) x, ꢀy, z ꢀ 1/2; (xvii) x, y + 1, z; (xviii)
ꢀx + 1, y + 1/2, ꢀz + 3/2; (xix) ꢀx + 1, y ꢀ 1/2, ꢀz + 3/2; (xx) ꢀx, ꢀy + 1, ꢀz + 1; (xxi) x, ꢀy + 1/2, z ꢀ 1/2; (xxii) x, ꢀy + 2, z + 1/2; (xxiii)
ꢀx + 1/2, ꢀy + 1/2, ꢀz + 1; (xxiv) x + 1/2, ꢀy ꢀ 1/2, z + 1/2; (xxv) ꢀx + 3/2, y+1/2, ꢀz + 1/2; (xxvi) ꢀx + 2, ꢀy, ꢀz + 1; (xxvii) ꢀx + 1, ꢀy,
ꢀz + 1.

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K. Slepokura / Carbohydrate Research 343 (2008) 113–131
122
and water molecules coordinating to the metal cations
(Table 4). The overall structures of the layers are similar
in all the salts presented here. Their interior is filled with
metal cations and the [(MeO)2cDHAP]ꢀ anions are
located on both sides of the double layers, locating their
phosphate groups inward (towards the metal ions) and
the methoxy groups to the interlayer exterior. The result
of such arrangement of the individual components in the
crystal networks is the aggregation of the hydrophilic
and hydrophobic groups into two distinct regions in
crystals 5d–g. The crystal structures are additionally sta-
bilized by the networks of O–Hꢁ ꢁ ꢁO and C–Hꢁ ꢁ ꢁO
hydrogen bonds, of the geometrical parameters given
in Table 5.
from another (O1W–H1Wꢁ ꢁ ꢁO4viii and O2W–
H4Wꢁ ꢁ ꢁO4xvi). These hydrogen bonds, in combination
with the C–Hꢁ ꢁ ꢁO contacts, give rise to double layers
parallel to the (100) plane.
Quite different is the coordination manner in the crys-
tals of two potassium salts K[(MeO)2cDHAP]Æ1.5H2O
(5e) and K[(MeO)2cDHAP]Æ0.5H2O (5e0). Two crystal-
lographically independent [(MeO)2cDHAP]ꢀ anions in
5e coordinate to the metal cations by the endo- and
exocyclic phosphate oxygen atoms (O31, O51 in 5e-1
and O32, O42, O52 in 5e-2), as well as by the acetal O
atoms (O221 in 5e-1 and O222 in 5e-2) (Fig. 7). How-
ever, only phosphate O atoms (exocyclic O4 and O5
and endocyclic O1) coordinate to the potassium cations
in 5e0 (Fig. 7). The coordination spheres of the three
different K+ ions in 5e and 5e0 are also different: the
coordination numbers of two crystallographically inde-
pendent metal cations in 5e, K1 and K2, and the K atom
in 5e0 are 8, 7 and 6, respectively (Fig. 8, Table 4). The
polyhedron of atom K1 is built up from six oxygen
atoms from four different organic anions and two O
atoms from water molecules, and that of K2 is formed
by five oxygen atoms from three different
[(MeO)2cDHAP]ꢀ anions and two from water mole-
cules. The coordination environment of K+ ion in 5e0
is composed of five oxygen atoms from four different
organic anions and one from a water molecule (Fig. 8,
Table 4). It is to be mentioned here that some of the oxy-
gen atoms coordinate to two or even three different
potassium cations simultaneously (Fig. 7): O5 in 5e-1
and 5e0 coordinates to three K atoms, O4 and O5 in
5e-2 coordinates to two different K+. Packing diagrams
revealing the differences in the overall structures of 5e
In the crystal of sodium salt 5d, each Na+ ion is coor-
dinated by two symmetry-related [(MeO)2cDHAP]ꢀ
anions and by four water molecules. However, the same
organic anion is coordinated (by its exocyclic phosphate
O5 atom) to two different sodium cations in a manner
as shown in Figure 6. The Na–O distances in sodium
coordination polyhedron (of a geometry of distorted
˚
octahedron) are in the range of 2.360(2)–2.499(2) A
(Table 4). The anions as well as water molecules coordi-
nate simultaneously to two adjacent sodium cations,
which leads to polymeric chains along the b-axis,
˚
with Naꢁ ꢁ ꢁNa distances of 3.282(1) A (Fig. 6). The
structure of the chain is stabilized by O–Hꢁ ꢁ ꢁO and
C–Hꢁ ꢁ ꢁO hydrogen bonds involving both water mole-
cules, phosphate endo- and exocyclic (O3 and O4)
oxygen atoms as well as the acetal O22 (Table 5). The
adjacent chains are joined with each other by the
O–Hꢁ ꢁ ꢁO interactions formed between water molecules
from the one chain and phosphate, exocyclic O4 atoms
a
c
0
b
Figure 6. Polymeric chains along the b-axis formed by the coordination of [(MeO)2cDHAP]ꢀ anions and water molecules to sodium cations in 5d.
O–Hꢁ ꢁ ꢁO and C–Hꢁ ꢁ ꢁO hydrogen interactions stabilizing the chain structure are shown with dashed and dotted lines, respectively. Symmetry codes
are listed in Tables 4 and 5.

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K. Slepokura / Carbohydrate Research 343 (2008) 113–131
123
5e-1
5e-2
5e'
K1 in 5e
K2 in 5e
Figure 7. The environment of the [(MeO)2cDHAP]ꢀ anions in
potassium salts: two crystallographically independent anions 5e-1
and 5e-2 in K[(MeO)2cDHAP]Æ1.5H2O (5e) and one anion in
K[(MeO)2cDHAP]Æ0.5H2O (5e0). Displacement ellipsoids are shown
at the 30% probability level. The metal cations are shown as circles of
arbitrary radii. Symmetry codes are given in Tables 4 and 5. (@) x, y,
z + 1.
K in 5e'
Figure 8. Coordination environment of two crystallographically
independent K1 and K2 in K[(MeO)2cDHAP]Æ1.5H2O (5e) and one
K+ ion in K[(MeO)2cDHAP]Æ0.5H2O (5e0). Symmetry codes are given
in Table 4.
and 5e0 crystals are shown in Figure 9. K–O and Kꢁ ꢁ ꢁK
distances are listed in Table 4.
atoms O4 and O5. To every Ca2+ ion (located on a two-
fold axis) coordinate four organic anions (two of them
by the O4 atoms, two others by O5) and two water
molecules. The geometry of coordination polyhedron
The [(MeO)2cDHAP]ꢀ anions in the calcium salt 5f
coordinate to the metal cation by both exocyclic oxygen

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K. Slepokura / Carbohydrate Research 343 (2008) 113–131
124
is close to octahedral with the Ca–O distances from
C–Hꢁ ꢁ ꢁO type. All this gives rise to a double-layered
architecture for the 5f crystal, with the layers parallel
to the (100) plane.
˚
2.259(1) to 2.383(1) A (Table 4). Every [(MeO)2-
cDHAP]ꢀ anion is coordinated to two adjacent calcium
cations (by its O4 atom to one of them and by O5 to
another) in a manner as shown in Figure 10. This results
in polymeric chains along the c-axis of the 5f crystal,
In the crystal of mixed, calcium–potassium salt 5g,
each from three crystallographically independent
[(MeO)2cDHAP]ꢀ anions coordinates to the metal
cation in a different manner, as shown in Figure 11.
The anions denoted as 5g-2 and 5g-3 utilize two phos-
phate oxygen atoms (5g-2: O42, O52, and 5g-3: O13,
O53) to coordinate to both K+ and Ca2+. However,
the 5g-1 anion coordinates by as many as four different
O atoms, three phosphate and one acetal: O31, O41,
O51 and O221. Such differences observed in the chemi-
cal environments of the three anions and the way they
coordinate to the metal centres may be the reason of
the differences in deformation of the chair conformation
˚
with the Caꢁ ꢁ ꢁCa distances of 5.643(1) A. Their struc-
ture is stabilized by OW–H1Wꢁ ꢁ ꢁO21x hydrogen bonds
formed between water molecules and acetal oxygen
atoms (symmetry codes and geometry of proposed
hydrogen bonds are given in Table 5). Furthermore,
the water molecules are also involved in hydrogen
bonding with the phosphate endocyclic O1 atoms of
the anions from different, symmetry-related chains
(OW–H2Wꢁ ꢁ ꢁO1xvii). Additionally, the adjacent chains
are joined with each other by the weak interactions of
5e
5e'
Figure 9. Packing diagrams for the potassium salts crystals: 5e (viewed down the c-axis) and 5e0 (viewed down the b-axis and c-axis), showing the
layer architecture of the crystals. Non-coordinating to K+ ions O3W water molecules in 5e are omitted for clarity.

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K. Slepokura / Carbohydrate Research 343 (2008) 113–131
125
a
b
0
c
Figure 10. Polymeric chains along the c-axis formed by the coordination of [(MeO)2cDHAP]ꢀ anions and water molecules to calcium cations in 5f.
OW–H1Wꢁ ꢁ ꢁO21x hydrogen bonds stabilizing the chain structure are shown with dashed lines. Symmetry codes are listed in Tables 4 and 5.
of six-membered 1,3,2-dioxaphosphorinane ring (P/O1/
C1/C2/C3/O3), discussed earlier.
salts with both organic and inorganic cations: (cha)-
[(MeO)2cDHAP]Æ3H2O (5a), (cha)[(MeO)2cDHAP]Æ
H2O (5b), (H5O2)[(MeO)2cDHAP] (5c), Na[(MeO)2-
cDHAP]Æ2H2O (5d), K[(MeO)2cDHAP]Æ1.5H2O (5e),
K[(MeO)2cDHAP]Æ0.5H2O (5e0), Ca[(MeO)2cDHAP]2Æ
2H2O (5f), CaK[(MeO)2cDHAP]3Æ2H2O (5g) and
NH4[(MeO)2cDHAP] (5h). This allowed us to discuss
the geometry of [(MeO)2cDHAP]ꢀ anions in detail,
mainly the conformation of the P/O/C/C/C/O 1,3,2-
dioxaphosphorinane ring, and compare it with that of
the phenyl derivative, (MeO)2cDHAP(Ph) (4). In addi-
tion, the chemical environment of the anions, as well
as the arrangement mode in the crystal lattices, was also
presented. The X-ray structures reported for all the nine
compounds revealed that the dioxaphosphorinane ring
in 5a–g exists in the chair conformation, in generally
only slightly flattened, in contrast to the deformations
observed in the analogous phenyl derivative 4. However,
the anion in 5h is disordered and exists in two conforma-
tions, 76% of which are in the skew conformation, which
has never been observed so far in compounds of related
structure.
The arrangement of the individual ions in the crystal
networks of all the nine (MeO)2cDHAP salts presented
here (5a–h) results in aggregation of the hydrophilic
and hydrophobic groups into two distinct regions in
the crystals similar to that which was observed in the
crystals of the acyclic analogue, 6a–e. The characteristic
of the crystal packing mode of 5a–h is the layer architec-
ture, with well-defined double layers formed in the salts
with inorganic cations, 5d–g.
Each Ca2+ ion in the 5g crystal is coordinated by five
organic anions (two symmetry-related 5g-1, two 5g-2
and one 5g-3) and one water molecule. The K+ ion is
coordinated by four [(MeO)2cDHAP]ꢀ anions (5g-2,
5g-3 and two symmetry-related 5g-1) and by one water
molecule. All the five organic anions in the environment
of calcium cation act as monodentate ligands for Ca2+
.
However, three of four anions coordinating the potas-
sium cation chelate K+ in a bidentate manner. The
Ca–O distances in a slightly deformed octahedral coor-
dination sphere of calcium cation are in the range of
˚
2.309(2)–2.354(2) A (Table 4, Fig. 12), while the K–O
distances in the coordination polyhedron of potassium
cation (coordination number = 8) are from 2.731(2) to
˚
3.135(2) A (Table 4).
The adjacent Ca2+ and K+ ions, along with the coor-
dinating [(MeO)2cDHAP]ꢀ anions, are arranged in the
chains parallel to the b-axis in the crystal of 5g
(Fig. 13a). The Caꢁ ꢁ ꢁK and Caꢁ ꢁ ꢁKxiii distances within
the chain are almost equal and amount to 4.040(2)
˚
and 3.994(1) A. The 5g-1 and 5g-3 anions coordinate
to a single [Caꢁ ꢁ ꢁK]nꢁ ꢁ ꢁCa chain, while the 5g-2 anions
fulfill a function as linkers between two adjacent chains.
ꢀ
This gives rise to layers parallel to the ð101Þ plane of 5g,
the simplified structure of which (with 5g-1,3 omitted) is
shown in Figure 13b.
3. Conclusions
Five different crystals of the salts containing inor-
ganic cations: sodium 5d, potassium 5e, 5e0, calcium 5f
and calcium and potassium together 5g, allowed us to
establish the characteristics of the coordination of
The dimethyl acetal of cyclic dihydroxyacetone phos-
phate, (MeO)2cDHAP, the cDHAP precursor, was syn-
thesized and crystallized in the form of nine different

´
K. Slepokura / Carbohydrate Research 343 (2008) 113–131
126
5g-1
5g-2
Figure 12. Coordination environment of calcium and potassium
cations in CaK[(MeO)2cDHAP]3Æ2H2O (5g). Three crystallographically
independent anions are drawn with different line types: 5g-1, solid; 5g-2,
open; 5g-3, solid dashed. Symmetry codes are given in Table 4.
only one or two exocyclic phosphate O atoms coordi-
nating to sodium and calcium, respectively, in the 5d,
and 5f,g crystals, compared to three O atoms in 5e0,
and as much as four (both exo-, endocyclic and even
acetal O atoms) coordinating to K+ in 5e and 5g. Addi-
tionally, it is worth mentioning that the respective
[(MeO)2cDHAP]ꢀ anions act as monodentate groups
for both Na+ and Ca2+ (also in the calcium–potassium
salt, 5g), whereas they chelate K+ ions with two or even
three O atoms in both potassium 5e, 5e0, and calcium–
potassium salts (anions 5g-1, 5g-3). Such significantly
higher affinity of the [(MeO)2cDHAP]ꢀ anions to potas-
sium cations, compared with the other metal ions, is
similar to that observed in the non-cyclic analogue,
[(MeO)2DHAP]2ꢀ, which coordinates to only two Na+
and to as much as seven different K+ ions.15
5g-3
Figure 11. The environment of the three crystallographically indepen-
dent [(MeO)2cDHAP]ꢀ anions in calcium–potassium salt 5g. Dis-
placement ellipsoids are shown at the 30% probability level. The metal
cations are shown as circles of arbitrary radii. Symmetry codes are
given in Tables 4 and 5.
[(MeO)2cDHAP]ꢀ anions depending on the metal
cation. It is evident that the coordination mode is similar
in both the sodium and calcium environment (5d,f,g),
where only exocyclic phosphate O atoms are involved,
and polymeric chains, linked together to form layers,
are observed (as in 5d,f). There are only two metal
cations in the close environment of the anions in 5d,f.
In the case of potassium-containing salts 5e,e0,g, the
coordination mode is much more complex, and usually
involves three or four cations bonded to the anions.
All that is reflected in the quantity and type of a single
anion oxygen atoms acting in bonding to the cations:
4. Experimental
4.1. General experimental procedures
Ba(OH)2Æ8H2O (Avocado) was recrystallized from water
before use (if necessary). N2 was passed through the

´
K. Slepokura / Carbohydrate Research 343 (2008) 113–131
127
a
b
Figure 13. (a) A packing diagram for 5g, viewed down the b-axis, showing the layer architecture and the chains built up from the alternate
arrangement of the Ca2+ and K+ ions, 5g-1, 5g-2 and 5g-3 [(MeO)2cDHAP]ꢀ ions and water molecules coordinating to them. (b) The arrangement of
ꢀ
the metal cations within the layer parallel to ð101Þ plane, along with the 5g-2 anions joining the adjacent three chains into the layer. The remaining
anions and water molecules are omitted for clarity. Symmetry codes are given in Table 4.
distilled water before its use in the reactions with barium
hydroxide. Cyclohexylamine (cha) was purchased from
Aldrich. Bis(cyclohexylammonium) sulfate, (cha)2SO4,
was synthesized from cyclohexylamine and H2SO4.19
Dowex 50-H+ · 2–100 (Serva) was regenerated after
use by washing it with about 100 mL of 3–4 M HCl
and then with water until the pH was neutral.
Melting points were recorded on a Boe¨tius PHMK
(VEB Analytik Dresden) melting point apparatus and
are uncorrected. NMR spectra were recorded using a
Bruker Avance 500 spectrometer. Mass spectra were
recorded on a Finnigan MAT TSQ 700 spectrometer.
4.2. Synthesis of compound 5a
Ba(OH)2 solution (400 mL, 0.1 M) was heated up to 96–
98 ꢁC. To this vigorously stirred solution, compound 4
(4.0 g, 14.6 mmol), was added. Two layers formed as 4
dissolved, and then disappeared after heating the mix-
ture for 20 min, indicating the completion of the hydro-
lysis of phenyl ester. The mixture was then cooled to
room temperature, and a solution of (cha)2SO4 (0.32 g,
1.1 mmol, 10% excess) in 7 mL of water was added.
The mixture was stirred for 15 min and then the BaSO4
that precipitated was removed by centrifugation (ꢂ5000

´
K. Slepokura / Carbohydrate Research 343 (2008) 113–131
128
1
rpm) and washed several times with small amounts of
water. The filtrate and the washings were evaporated
under reduced pressure (T < 40 ꢁC). The solid residue
was dissolved in boiling abs EtOH, and the mixture
to air dry (195 mg, 55%). Mp 135–138 ꢁC. H NMR
(500 MHz; D2O, Me4Si; 297 K) d 4.11 (4H, d, J
12.2 Hz), 3.26 (6H, s); ESIMS m/z 197 (Mꢀ).
was filtered on a Buchner funnel in order to remove
¨
4.3. Preparation of the compounds. Crystallization
the excess of (cha)2SO4 and the inorganic phosphates
that possibly formed. If the filtrate was still cloudy,
the methods of purification described by Ferroni
et al.12 were applied. Pure compound 5 was dissolved
in small amount of water (about 0.5 mL) and the pH
of the solution was adjusted to pH 10 with cha. Acetone
(1.5 mL) was added, and the mixture was moved to a
refrigerator (ꢂ7 ꢁC) for 10 h. The crystals of compound
4.3.1. (cha)[(MeO)2cDHAP]Æ3H2O (5a) and (cha)[(MeO)2-
cDHAP]ÆH2O (5b). Water (100 lL) was added to
100 mg of compound 5, and the vessel was moved to
the temperature of ꢀ18 ꢁC. Very small crystals so
obtained were used as the crystal nuclei in further recrys-
tallizations from water (for 5a) and EtOH or 2-PrOH
(for 5b) at 4–7 ꢁC, which gave large, colourless parallel-
epipeds of 5a or 5b (mp 145–150 ꢁC), respectively, with
different numbers of water molecules. Fragments of
5 so obtained were filtered on a Buchner funnel, washed
¨
several times with small amounts of acetone and allowed
Table 6. Experimental data for 5a–d
(cha)[ANION]Æ3H2O (5a)
(cha)[ANION]ÆH2O (5b)
(H5O2)[ANION] (5c)
Na[ANION]Æ2H2O (5d)
Crystal data
Empirical formula
Formula weight (g molꢀ1
Crystal system
C
351.33
Monoclinic
P21/c
11H30NO9P
C11H26NO7P
315.30
Monoclinic
P21/c
C5H15O8P
234.14
Orthorhombic
Pca21
C5H14NaO8P
256.12
Monoclinic
C2/c
)
Space group
˚
a (A)
8.430(2)
25.516(4)
8.269(2)
95.14(3)
1771.5(7)
4
1.317
1.761
760
14.126(3)
12.449(3)
8.883(2)
99.89(3)
1538.9(6)
4
1.361
0.208
680
8.497(2)
7.176(2)
17.613(3)
27.654(4)
6.448(2)
11.988(3)
96.40(2)
2124.3(9)
8
1.602
0.321
1072
˚
b (A)
˚
c (A)
b (ꢁ)
3
˚
V (A )
1073.9(4)
4
1.448
0.274
496
Z
Dcalc (g cmꢀ3
l (mmꢀ1
F(000)
)
)
Crystal size (mm)
Crystal colour
Crystal form
0.33 · 0.17 · 0.09
Colourless
Parallelepiped
0.38 · 0.13 · 0.09
Colourless
Parallelepiped
0.38 · 0.35 · 0.15
Colourless
Thick plate
0.35 · 0.26 · 0.09
Colourless
Plate
Data collection
˚
Radiation type, k (A)
T (K)
Cu Ka, 1.5418
100(2)
Mo Ka, 0.71073
100(2)
Mo Ka, 0.71073
100(2)
Mo Ka, 0.71073
100(2)
h Range (ꢁ)
h,k,l range
3.46–75.96
ꢀ10 6 h 6 10
ꢀ31 6 k 6 31
ꢀ9 6 l 6 5
Analytical
0.635/0.858
19388
3539
3227
0.0337
3.01–37.07
ꢀ23 6 h 6 23
ꢀ20 6 k 6 20
ꢀ11 6 l 6 15
—
—
25457
7390
4834
3.66–37.48
ꢀ14 6 h 6 14
ꢀ12 6 k 6 12
ꢀ20 6 l 6 28
—
—
16045
4097
3635
3.25–36.45
ꢀ36 6 h 6 45
ꢀ5 6 k 6 8
ꢀ15 6 l 6 15
Analytical
0.904/0.970
8343
3099
2334
0.0475
Absorption correction
Tmin/Tmax
Measured reflections
Independent reflections
Observed refl. (I > 2r(I))
Rint
0.0419
0.0286
Refinement
Refinement on
F2
F2
F2
F2
Data/restraints/parameters
R1; wR2ðF 2o > 2rðF 2oÞÞ
R1;wR2 (all data)
3539/0/320
0.0382; 0.1050
0.0409; 0.1079
1.047
7390/0/285
0.0365; 0.0708
0.0698; 0.0754
1.032
4097/0/186
0.0321; 0.0738
0.0385; 0.0756
1.035
3099/0/192
0.0483; 0.1175
0.0653; 0.1234
1.043
GooF = S
Weighting parameter a/b
0.0826/0.2294
0.35/ꢀ0.40
—
0.0300/0.0
0.48/ꢀ0.32
—
0.0458/0.0
0.45/ꢀ0.21
ꢀ0.05(6)
0.0769/ 0.0
0.83/ꢀ0.35
—
ꢀ3
˚
Dqmax/Dqmin (e A
)
Flack parameter
ANION = (MeO)2cDHAP.
R1 ¼ jjF oj ꢀ jF cjj= jF oj; wR2 ¼
qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
P
P
P
P
2
2
2
½wðF o2 ꢀ F c2Þ ꢃ= ½wðF o2Þ ꢃ; weighting scheme: w ¼ 1=½r2ðF 2oÞ þ ðaPÞ þ bPꢃ where P ¼ ðF o2 þ 2F 2c Þ=3.

Table 7. Experimental data for 5e–h
K[ANION]Æ1.5H2O (5e)
K[ANION]Æ0.5H2O (5e0)
Ca[ANION]2Æ2H2O (5f)
CaK[ANION]3Æ2H2O (5g)
NH4[ANION] (5h)
Crystal data
Empirical formula
C5H13KO7.50
263.22
Monoclinic
P21/c
P
C5H11KO6.50
245.21
Monoclinic
C2/c
P
C10H24CaO14P2
470.31
Monoclinic
C2/c
C15H34CaKO20P3
706.51
Monoclinic
P21/n
C5H14NO6P
215.14
Monoclinic
P21/c
Formula weight (g molꢀ1
Crystal system
)
Space group
˚
a (A)
14.033(3)
13.923(4)
11.396(4)
108.33(3)
2113.6(11)
8
1.654
0.670
1096
34.593(6)
6.995(3)
8.187(3)
102.20(3)
1936.3(11)
8
1.682
0.717
1016
24.540(3)
8.360(2)
9.736(2)
111.54(2)
1857.9(6)
4
1.681
0.580
984
17.667(3)
10.059(2)
17.734(3)
115.77(3)
2838.1(9)
4
1.653
0.622
1472
12.258(5)
6.869(3)
11.438(5)
97.63(3)
954.6(7)
4
1.497
2.655
456
˚
b (A)
˚
c (A)
b (ꢁ)
3
˚
V (A )
Z
Dcalc (g cmꢀ3
l (mmꢀ1
F(000)
)
)
Crystal size (mm)
Crystal colour
Crystal form
0.12 · 0.02 · 0.02
Colourless
Needle
0.28 · 0.24 · 0.02
Colourless
Plate
0.30 · 0.10 · 0.03
Colourless
Plate
0.30 · 0.16 · 0.03
Colourless
Plate
0.19 · 0.03 · 0.02
Colourless
Plate
Data collection
˚
Radiation type, k (A)
T (K)
Mo Ka, 0.71073
100(2)
Mo Ka, 0.71073
100(2)
Mo Ka, 0.71073
100(2)
Mo Ka, 0.71073
100(2)
Cu Ka, 1.5418
240(2)
h Range (ꢁ)
h,k,l range
2.93–26.00
ꢀ17 6 h 6 17
ꢀ17 6 k 6 17
ꢀ10 6 l 6 14
Multi-scan
0.909/1.000
22036
2.97–26.00
ꢀ42 6 h 6 42
ꢀ8 6 k 6 7
ꢀ10 6 l 6 9
Analytical
0.845/0.977
6105
3.21–37.41
ꢀ41 6 h 6 41
ꢀ14 6 k 6 14
ꢀ14 6 l 6 16
Analytical
0.862/0.978
15337
3.07–28.00
ꢀ23 6 h 6 22
ꢀ13 6 k 6 13
ꢀ23 6 l 6 23
Analytical
0.868/0.983
25288
3.64–76.40
ꢀ15 6 h 6 13
ꢀ8 6 k 6 5
ꢀ12 6 l 6 14
Analytical
0.753/0.945
7857
Absorption correction
Tmin/Tmax
Measured reflections
Independent reflections
4149
1895
4530
6794
1890
Observed reflections (I > 2r(I))
Rint
1814
0.1949
1330
0.0452
2877
0.0629
4568
0.0584
1188
0.0569
Refinement
Refinement on
F2
F2
F2
F2
F2
Data/restraints/parameters
R1; wR2ðF 2o > 2rðF 2oÞÞ
R1;wR2 (all data)
GooF = S
4149/0/288
0.0490; 0.0671
0.1453; 0.0790
1.006
1895/0/129
0.0395; 0.0919
0.0653; 0.0978
1.056
4530/0/171
0.0417; 0.0548
0.0855; 0.0590
1.044
6794/0/497
0.0413; 0.0589
0.0840; 0.0652
1.016
1890/0/174
0.0468; 0.1193
0.0746; 0.1378
1.007
Weighting parameter a/b
0.0/0.0
0.50/ꢀ0.41
0.0515/0.0
0.75/ꢀ0.31
0.0100/0.0
0.49/ꢀ0.47
0.02/0.0
0.35/ꢀ0.34
0.07/0.0
0.25/ꢀ0.29
ꢀ3
˚
Dqmax/Dqmin (e A
)
ANION = (MeO)2cDHAP.
R1 ¼ jjF oj ꢀ jF cjj= jF oj; wR2 ¼
qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
P
P
P
P
2
2
2
½wðF o2 ꢀ F c2Þ ꢃ= ½wðF o2Þ ꢃ; weighting scheme: w ¼ 1=½r2ðF 2oÞ þ ðaPÞ þ bPꢃ where P ¼ ðF o2 þ 2F 2c Þ=3.

´
K. Slepokura / Carbohydrate Research 343 (2008) 113–131
130
the crystals so obtained were used for the X-ray diffrac-
tion measurements.
full-matrix least-squares technique using SHELXL-9722
with anisotropic thermal parameters for all non-H
atoms. All H atoms were found in difference-Fourier
maps and were refined isotropically for 5a–d and 5f,g.
In the final refinement cycles for 5e, 5e0 and 5h, all the
H atþoms (except for those from water molecules and
NH4 ion) were treated as riding atoms, with C–H dis-
4.3.2. (H5O2)[(MeO)2cDHAP] (5c). A solution of com-
pound 5a (100 mg, 0.28 mmol) in a minimal quantity of
water was passed through an ion-exchange column
(Dowex 50-H+). The acidic solution was evaporated
under a nitrogen stream yielding a syrup that was sub-
jected to crystallization at ꢀ18 ꢁC in order to prevent
the hydrolysis of the acetal group. Water (100 lL) was
added to the small crystals of 5c so obtained, and the
crystallization was allowed to continue at 4 ꢁC. Large,
colourless parallelepipeds of 5c were obtained after three
days. The crystals were hygroscopic and were measured
immediately.
˚
tances of 0.97–0.99 A and with Uiso values of 1.2Ueq(C)
for CH2 groups or 1.5Ueq(C) for CH3. In 5e, H3W and
H6W atoms from water molecules were refined with
Uiso = 1.5Ueq(O). The extinction was also refined in
5a,h with the final extinction coefficient amounting to
0.0047(5) in 5a and 0.0014(6) in 5h. The Flack parameter
in 5c was ꢀ0.05(6). All figures were made using an XP
program.23 Cremer–Pople puckering parameters were
calculated using the PLATON program.24 A summary of
the conditions for the data collection and the structure
refinement parameters are given in Tables 6 and 7.
The X–ray data for NH4[(MeO)2cDHAP] (5h) were
collected at 240(2) K owing to weak reflections at b*/3
and 2b*/3 observed at lower temperatures. (DSC analy-
sis for 5h confirmed a phase transition about 220 K.)
The [(MeO)2cDHAP]ꢀ ion in 5h is disordered into two
positions corresponding to two different conformations
of the 1,3,2-dioxaphosphorinane ring: skew (S) with
s.o.f = 0.762(9) and chair (C) with s.o.f. = 0.238(9). In
the final model, the ordered atoms of the anion (O21,
O3, O4, O5, C3 and C4) were refined with s.o.f = 1,
assuming their positions being common for the two con-
formations. Remaining atoms were treated as disor-
dered, and their two positions (P/P10, O1/O10, O22/
O220, C1/C10, C2/C20 and C5/C50) were refined with
s.o.f = 0.762(9) and 0.238(9). The positions of pairs of
the atoms P and P10, as well as C2 and C20, were
refined with the same fractional coordinates and aniso-
tropic displacement parameters (constrains were applied
with EXYZ and EADP instructions).
4.3.3. Na[(MeO)2cDHAP]Æ2H2O (5d), K[(MeO)2cDHAP]Æ
1.5H2O (5e), [(MeO)2cDHAP]Æ0.5H2O (5e0), Ca[(MeO)2-
cDHAP]2Æ2H2O (5f), CaK[(MeO)2cDHAP]3Æ2H2O (5g)
and NH4[(MeO)2cDHAP] (5h). To the acidic eluant
(water solutions of 5c) freshly prepared from 25 mg
(0.07 mmol) of 5a, the respective bicarbonate: NaHCO3
for 5d, KHCO3 for 5e and 5e0, NH4HCO3 for 5h (in a
molar ratio 1:1) or CaCl2Æ6H2O (in a molar ratio 2:1)
for 5f or KHCO3 and CaCl2Æ6H2O (in a molar ration
1:1:1) for 5g were added. A small amount of EtOH
was added to 5h. The solutions were evaporated under
a nitrogen stream to syrups, which were allowed to crys-
tallize at 21 ꢁC (for 5d,h,e0) or 4 ꢁC (for 5e,f,g). Calcium
and potassium salts were obtained by the addition of a
small amount of water with repeated evaporation of
the mixtures. Crystals of 5e0 were grown by recrystalliza-
tion of the nuclei from a mixture of 1:1:1 MeOH–
EtOH–2-PrOH and a small amount of water. Crystals
of 5d–e0 and 5h showed a huge tendency to twinning
and could not be cut; therefore, these had to be swilled
with water to obtain the size required for the X-ray
experiment.
4.4. Crystal structures determination
Acknowledgement
The crystallographic measurements for 5a–h were per-
formed on a Xcalibur PX (for 5a,h) or a Kuma
KM4CCD (for 5b–g) automated four-circle diffracto-
meters with the graphite-monochromatized CuKa
(5a,h) or MoKa (5b–g) radiation. The data for the
crystals were collected at 100(2) K (for 5a–g) or
240(2) K (for 5h) using an Oxford Cryosystems cooler.
Data collection, cell refinement, and data reduction
and analysis were carried out with the Xcalibur PX or
KM4CCD software (Oxford Diffraction Poland), CRY-
SALIS CCD and CRYSALIS RED, respectively.20 Analytical
or multi-scan absorption correction was applied to all
the data, except for the 5b and 5c crystals, with the
use of CRYSALIS RED.20 All structures were solved by
direct methods using SHELXS-9721 and refined by a
The financial support of this work by The Polish State
Committee for Scientific Research under Grant No. 3
T09A 047 27 is gratefully acknowledged.
Supplementary data
Complete crystallographic data for the structural analy-
sis have been deposited with the Cambridge Crystallo-
graphic Data Centre, CCDC No. 659905 (5a), 659906
(5b), 659907 (5c), 659908 (5d), 659909 (5e), 659910
(5e0), 659911 (5f), 659912 (5g) and 659913 (5h). Copies
of this information may be obtained free of charge from
the Director, Cambridge Crystallographic Data Centre,
12 Union Road, Cambridge, CB2 1EZ, UK. (fax: +44-

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K. Slepokura / Carbohydrate Research 343 (2008) 113–131
131
12. Ferroni, E. L.; DiTella, V.; Ghanayem, N.; Jeske, R.;
Jodlowski, C.; O’Connel, M.; Styrsky, J.; Svoboda, R.;
Venkataraman, A.; Winkler, B. M. J. Org. Chem. 1999,
64, 4943–4945.
1223-336033, e-mail: deposit@ccdc.cam.ac.uk or via:
www.ccdc.cam.ac.uk). Supplementary data associated
with this article can be found, in the online version, at
doi:10.1016/j.carres.2007.09.011.
´
13. Slepokura, K.; Lis, T. Carbohydr. Res. 2004, 339, 1995–
2007.
´
14. Slepokura, K.; Lis, T. Acta Crystallogr. Sect. C 2004, 60,
o315–o317.
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