Synthesis and kinetic evaluation of 4-deoxy-4-phosphonomethyl-D- erythronate, the first hydrolytically stable and potent competitive inhibitor of ribose-5-phosphate isomerase

Article abstract of DOI:10.1016/j.tetlet.2004.03.004

4-deoxy-4-Phosphonomethyl-D-erythronate, an isosteric and hydrolytically stable analogue of the known ribose-5-phosphate isomerase inhibitor 4-deoxy-4-phospho-D-erythronate, was obtained by a 14-step synthesis from D-arabinose through an highly improved s

Full text of DOI:10.1016/j.tetlet.2004.03.004

Tetrahedron
Letters
Tetrahedron Letters 45 (2004) 3465–3469
Synthesis and kinetic evaluation of 4-deoxy-4-phosphonomethyl-D-
erythronate, the first hydrolytically stable and potent competitive
inhibitor of ribose-5-phosphate isomerase
Emmanuel Burgos and Laurent Salmon*
Laboratoire de Chimie Bioorganique et Bioinorganique, CNRS-UMR 8124, Institut de Chimie Molꢀeculaire et des Matꢀeriaux d’Orsay
(ICMMO), B^atiment 420, Universitꢀe Paris-Sud XI, F-91405 Orsay, France
Received 13 February 2004; accepted 2 March 2004
Abstract—4-deoxy-4-Phosphonomethyl-
phosphate isomerase inhibitor 4-deoxy-4-phospho-
highly improved synthesis of the precursor 5-deoxy-5-phosphonomethyl-
and potent competitive inhibitor of the enzyme catalyzed isomerization of ribose-5-phosphate to
D
-erythronate, an isosteric and hydrolytically stable analogue of the known ribose-5-
-erythronate, was obtained by a 14-step synthesis from -arabinose through a
-arabinose. The title compound appears as the first stable
-ribulose-5-phosphate
D
D
D
D
(Ki ¼ 74 lM, Km=Ki ¼ 100), exhibiting only a 3-fold weaker inhibitory activity than its phosphate analogue.
ꢀ 2004 Elsevier Ltd. All rights reserved.
Ribose-5-phosphate isomerase (RPI, EC 5.3.1.6), an
aldose–ketose isomerase involved in the pentose phos-
phate pathway, catalyzes the reversible isomerization
inhibitor of spinach RPI,2 with inhibitory properties
similar to that previously reported for the known RPI
inhibitor 4-deoxy-4-phospho-D-erythronate 1 (Scheme
reaction between
D
D
-ribose 5-phosphate (R5P) and
2).1 Because of the known sensitivity of the phosphate
group towards chemical and biological hydrolysis,3
4-deoxy-4-phosphonomethyl-D-erythronate 2 (Scheme
-ribulose 5-phosphate (Ru5P) (Scheme 1).1 The reac-
tion is thought to proceed through a proton transfer
mechanism and to involve a 1,2-cis-enediolate high-
energy intermediate. In course of our search for high-
energy intermediate analogue inhibitors of this reaction,
2) was designed as an isosteric and stable analogue of 1.
In phosphorylated molecules of biological interest,
replacement of the labile C–O–P bond by a C–C–P
bond4–10 greatly enhances the stability of such molecules
towards the action of digestive phosphatases, as well as
their potential bioactivity as inhibitors or regulators of
metabolic processes.11 Because enzymes of the pentose
phosphate pathway (and glycolysis) of some pathogenic
organisms like Trypanosoma brucei have been consid-
ered crucial for their survival and development,12
design of potent and stable RPI inhibitors might lead
we have recently reported 4-deoxy-4-phospho-
thronohydroxamic acid as a new and strong competitive
D-ery-
CHO
OH
OH
O
CH OH
2
1
2
-
O
RPI
RPI
OH
OH
OH
OH
OH
OH
2-
2-
2-
CH OPO
2
CH OPO
CH OPO
2 3
3
2
3
-O
O
-O
O
1,2-cis-enediolate
high-energy intermediate
R5P
Ru5P
OH
OH
OH
OH
Scheme 1. Isomerization reaction catalyzed by
isomerases.
D-ribose-5-phosphate
2-
2-
CH OPO
CH CH PO
3
2
3
2
2
1
2
Scheme 2. 4-deoxy-4-Phospho-D-erythronate (1) and 4-deoxy-4-phos-
phonomethyl-D-erythronate (2) as mimics of the 1,2-cis-enediolate
Keywords: Enzyme inhibitor; Phosphonate; Ribose-5-phosphate iso-
merase.
high-energy intermediate species of the RPI-catalyzed isomerization
reaction.
* Corresponding author. Tel.: +33-169-156311; fax: +33-169-157281;
e-mail: lasalmon@icmo.u-psud.fr
0040-4039/$ - see front matter ꢀ 2004 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tetlet.2004.03.004

3466
E. Burgos, L. Salmon / Tetrahedron Letters 45 (2004) 3465–3469
to molecules of therapeutic interest. Thus, we report in
this study the synthesis of 2 as the first isosteric and
stable reaction intermediate analogue of the R5P to
Ru5P isomerization reaction catalyzed by spinach RPI.
A comparison of its inhibitory properties with that of 1
is also reported.
reported.15 By-product dicyclohexylurea formed during
reaction was simply eliminated by addition of diethyl
ether. Following the reported Horner–Emmons con-
densation of 5 with the tetraethylmethylenediphospho-
nate carbanion using sodium hydride in diethyl
ether,13;14;22 the fully protected methyl 2,3-di-O-benzyl-5-
deoxy-5-diethylphosphonomethylene-a-D-arabinofur-
Our synthetic strategy to obtain 4-deoxy-4-phospho-
anoside 613;14 was isolated in 61% yield (two steps).
Hydrogenation of the double bound was achieved as
described with PtO2 (10 bar) to give methyl 2,3-di-O-
nomethyl-
methyl 2,3-di-O-benzyl-a-
(Scheme 3), which was prepared in five steps from
-arabinose using reported procedures.15–19 Conversion
of 3 to the known 5-deoxy-5-phosphonomethyl-
D
-erythronate 2 (Scheme 2) started from
D
-arabinofuranoside 313;14
benzyl-5-deoxy-5-diethylphosphonomethyl-a-D-arabi-
D
nofuranoside 7 in quantitative yield.13;14 Thereafter, our
strategy for the efficient deprotection of 7 started with
phosphonate ethyl ester hydrolysis, using TMSBr in
CH2Cl2 followed by NH3/H2O/MeOH hydrolysis, giv-
ing methyl 2,3-di-O-benzyl-5-deoxy-5-phosphonom-
D
-
arabinose 45;14;15 (Scheme 3) was then achieved in six
steps in 59% yield according to a highly improved pro-
cedure (lit.14 18%, lit.15 11%), leading thereafter to the
title compound by simple oxidative cleavage of the
phosphonomethyl precursor as depicted in Scheme 3.
Indeed, oxidation of 3 under Mofatt conditions13;14;20
led, after aqueous work-up, to a mixture of methyl 2,3-
ethyl-a-D-arabinofuranoside 8 as the bis(ammonium)
salt. After removal of NH4Br by trituration in CHCl3,
823 was obtained in quantitative yield. It was then
hydrogenolyzed (15 bar) over 10% Pd/C to afford methyl
di-O-benzyl-5-dehydro-a-
D
-arabinofuranoside 513;14 and
5-deoxy-5-phosphonomethyl-a-D-arabinofuranoside 9,
its hydrated forms 5a and 5b (Scheme 3) in approxi-
mately equal proportion.21 It should be noted that for-
mation of the hydrated forms of 5 may have led to
wrong conclusions about stability and purity of
the product of this reaction, which indeed does not
necessitate purification by silica gel chromatography as
bis(ammonium) salt24 in quantitative yield. Following
elution (H2O) on Dowexꢁ 50X4-400 (Hþ form), con-
centration and heating under argon for 3 h in water,15;18
the reaction mixture was concentrated, eluted (H2O) on
Dowexꢁ 50X4-400 (Naþ form) and freeze-dried to give
pure 5-deoxy-5-phosphonomethyl-a-
D
-arabinose 45;14;15
O
OEt
P
O
H
OH
O
OEt
O
H
HO
O
O
O
a
c
b
O
O
O
O
+
BnO
BnO
BnO
BnO
OBn
OBn
OBn
OBn
5
5a, 5b
6
3
O
P
O
P
O
P
O
P
OEt
OEt
O
ONH
ONH
O
ONH
ONa
ONa
4
4
ONH
4
4
e
O
O
d
f
O
O
O
OH
BnO
BnO
HO
HO
OBn
OBn
OH
O
OH
7
8
9
4
O
O
O
OH
OH
OH
OH
O
NaO
O
NaO
OH
OH
g
h
+
+
O
P
NaO
NaO
O
O
O
NaO
P
P
P
O
O
O
O
ONa
10
11
2
12
10
2
i
i
Scheme 3. Reagents and conditions: (a) i. DCC (5.3 equiv), DMSO, pyridine, TFA, 10 h, 25 ꢂC; ii. (CO2H)2, MeOH, 0 ꢂC; iii. Et2O, filtration; (b) i.
NaH (2 equiv), CH2[PO(OEt)2)2] (1.5 equiv), Et2O, 2 h; ii. 5, 5a and 5b mixture, 2 h, 61% (from 3); (c) H2, 10 bar, PtO2, CH2Cl2, 12 h, 100%; (d) i.
TMSBr (9 equiv), CH2Cl2, 24 h, 25 ꢂC; ii. NH3/H2/MeOH, 30 min, 100%; iii. CHCl3, filtration; (e) H2, 15 bar, Pd/C, CH2Cl2/MeOH (10/1), 12 h,
100%; (f) i. Dowexꢁ 50X4-400 (Hþ form), concentration; ii. H2O, reflux under argon, 3 h; iii. Dowexꢁ 50X4-400 (Naþ form), freeze drying, 97%; (g) i.
NaOH 0.5 Min water (3 equiv), 48 h, 25 ꢂC; ii. HCl, pH 1.5; iii. Ba(OH)2, pH 8.5; iv. Dowexꢁ 50X4-400 (Hþ form); (h) i. CH2N2, Et2O, MeOH; ii.
Silica gel chromatography (MeOH/AcOEt, 2/8), 54% (11) and 29% (12) (from 4); (i) TMSBr (4 equiv), CH2Cl2, 1 h, 0 ꢂC; ii. NH3/H2O/MeOH,
30 min; iii. Ba(OH)2; iv. Dowexꢁ 50X4-400 (Hþ form); v. Dowexꢁ 50X4-400 (Naþ form), freeze drying, 95%.

E. Burgos, L. Salmon / Tetrahedron Letters 45 (2004) 3465–3469
3467
as the disodium salt in 97% yield. This later deprotection
step of methyl 5-deoxy-5-dihydrogenophosphonom-
58:6 MÀ1 cmÀ1) at 25 ꢂC in 50 mMTris ÆHCl buffer
€
(pH 7.5). Apparent Michaelis constant (Km) and inhibi-
ethyl-a-
D
-arabinofuranoside to give compound 4 was
tion constant (Ki) were determined (Fig. 1) from double
reciprocal plots of the initial reaction velocity versus
R5P concentration obtained at various concentrations
of inhibitor 2 (Lineweaver–Burk graphical representa-
tion) with 0.5 U/mL of RPI (and replots of apparent
Km=Vmax values vs inhibitor concentration). IC50 deter-
minations were achieved for compound 10 using a
3.2 mMR5P concentration. As expected from its
structure, compound 10 is not a good mimic of the
enediolate high-energy intermediate (IC50¼5 mM). With
a Ki value of 74 lMand a Km=Ki ratio of 100 (Km
R5P¼7.5 mM), compound 2 behaves as a new potent
and competitive inhibitor of the isomerization reaction
of R5P to Ru5P catalyzed by spinach RPI. It is
remarkable to note that this Ki value we determined for
the phosphonomethyl inhibitor 2 is only about 3-fold
higher than the Ki value previously reported for its
phosphate analogue 1 (Ki ¼ 28 lM, Km=Ki ¼ 270),2 the
best known RPI inhibitor, which corresponds to a
0.6 kcal/mol decrease in the binding affinity of 2 versus 1
for the enzyme active site. Such a small value is unlikely
to correspond to the loss of a hydrogen bond (typically
in the range of 3–6 kcal/mol)34 reflecting the change in
the pKa2 value from phosphate to methylphosphonate
(7.5–6.5). It is however consistent with the loss of a weak
interaction between uncharged functions (typically
achieved very mildly by simple heating in water. Our
methodology differs from the reported one, which
mentioned the use of a cation-exchange resin (Dowexꢁ
50, Hþ form) in boiling water for the deprotection of the
acid form of 9.15 Indeed, hydrolysis of methyl 5-deoxy-
5-dihydrogenophosphate-a-
deoxy-5-dihydrogenophosphate-
D
-arabinofuranoside to 5-
D
-arabinose was also
reported to be achieved upon heating in water for 2 h
under argon without any degradation of the product.18
From our point of view, this facilitated hydrolysis of the
protected anomeric group is most likely due to intra-
molecular catalytic assistance by the phosphonic (or
phosphoric) acid group. Indeed, hydrolysis of the
methylated anomeric hydroxyl group prior to phos-
phonate deprotection was reported to require much
more drastic conditions (H2SO4 2 M, AcOH),13;14 which
led to compound 4 in much lower overall yield. In
contrast to what we had reported for the synthesis of
5-deoxy-5-phosphate-D-arabinonate from 6-deoxy-6-
phosphate-D D-glu-
-fructose25 or 6-deoxy-6-phosphate-
cose,26 oxidative cleavage (NaOH 0.5 M, molecular
oxygen, 2 days) of compound 4 gave not only the
expected 4-deoxy-4-phosphonomethyl-
but also the unexpected 3-deoxy-3-phosphonomethyl-
D-erythronate 2,
D
-
glycerate 10 in a 2:1 ratio (Scheme 3). Although it is
known from the reaction mechanism of aldose (or
ketose) oxidative cleavage proposed by Hendriks et al.
that different types of enediolate intermediates (which
lead to different products) may be formed,27 formation
of the two products surprised us. Indeed, oxidative
0.5–1.8 kcal/mol) and thus indicates that such
a
cleavage of 5-deoxy-5-phosphate-
deoxy-5-phosphate- -ribose) gave us only the expected
product 4-deoxy-4-phosphate- -erythronate 1 (results
D-arabinose (or 5-
D
D
not shown). Nevertheless, the two products 2 and 10
could be separated according to the following treatment.
Upon conversion to their respective methyl esters 11 and
12 (Scheme 3) using diazomethane,28 and separation by
silica gel chromatography (methanol/ethyl acetate¼2/8),
pure methyl 4-deoxy-4-dimethylphosphonomethyl-D-
erythronate 1129 (Rf ¼ 0:26) and 3-deoxy-3-dim-
ethylphosphonomethyl-
D
-glycerate 1230 (Rf ¼ 0:36)
were separated and obtained, respectively, in 54% and
29% yield from 4. Hydrolysis of the ester 11 was
accomplished using TMSBr in CH2Cl2 followed by
NH3/H2O/MeOH hydrolysis, which gave compound 2
as its bis(ammonium) salt. Upon addition of barium
hydroxide, compound 2 precipitated as its barium salt
and could be collected upon filtration. It was succes-
sively eluted (H2O) on Dowexꢁ 50X4-400 (Hþ form)
and Dowexꢁ 50X4-400 (Naþ form). Following lyophi-
lization, pure 2 as the disodium salt31 was recovered in
95% yield. The same procedure was used on the ester 12
to give compound 10 as its disodium salt32 in 95% yield.
Figure 1. Inhibition of spinach RPI (50 mMTris ÆHCl buffer, 25 ꢂC,
pH 7.5). Double reciprocal plot of initial reaction velocity versus R5P
concentration obtained at various concentration of inhibitor 2 versus
R5P concentration (Lineweaver–Burk graphical representation): s, no
inhibitor; j, [I]¼37 lM; }, [I]¼93 lM; ·, [I]¼140 lM; þ, [I]¼187 lM;
r, [I]¼374 lM; d, [I]¼935 lM. Lines drawn obtained from nonlinear
least squares fit to the observed data using Michaelis–Menten equation
for competitive inhibition.
The new compounds 2 and 10 were both evaluated
against spinach RPI (Aldrich) as potential inhibitors of
the R5P to Ru5P isomerization reaction (Scheme 1).
Enzymatic activities were determined by following the
change in ultraviolet absorbance that accompanies
conversion of R5P to Ru5P,33 (k ¼ 282 nm, ꢀ ¼

3468
E. Burgos, L. Salmon / Tetrahedron Letters 45 (2004) 3465–3469
18. Haehr, H.; Smallheer, J. Carbohydr. Res. 1978, 62, 178–
184.
19. Kirk, K. L. J. Heterocycl. Chem. 1985, 22, 57–59.
20. Pfitzner, K. E.; Moffatt, J. G. J. Am. Chem. Soc. 1937,
5661–5678.
21. Selected data for compound 5 (aldehyde form): 13C NM R
(50 MHz, CDCl3) d ¼ 200:7 (C-5), 137.9–137.2 (C-11),
128.6–128.0 (C-8, C-9, C-10), 108.4 (C-1), 86.8 (C-4), 84.7
(C-2), 82.7 (C-3), 72.2–71.8 (C-7), 55.4 (C-6); for com-
pounds 5a and 5b (hydrated forms of 5): 13C NM R
(50 MHz, CDCl3) d ¼ 137:9–137.2 (C-11ab), 128.6–128.0
(C-8ab, C-9ab, C-10ab), 107.8 and 107.5 (C-1a, C-1b), 97.3
and 97.2 (C-5b, C-5a), 87.4 and 87.2 (C-4b, C-4a), 85.7 and
84.1 (C-2b, C-2a), 83.4 and 83.8 (C-3b, C-3a), 72.2–71.8 (C-
7ab), 55.2 and 55.0 (C-6b, C-6a).
replacement of the oxygen atom for CH2 does not im-
pair significantly strong inhibition of spinach RPI. Con-
sequently, it does not seem useful in the case of RPI to
design monofluoromethylphosphonate analogues of 1,
as reported for the case of glucose-6-phosphate dehy-
drogenase inhibition by good phosphate surrogates.8
Comparison to the case of the fructose-6-phosphate
to glucose-6-phosphate isomerization catalyzed by an-
other aldose–ketose isomerase, namely phosphoglucose
isomerase (PGI), is quite interesting. Indeed, it has been
shown that such an oxygen for CH2 replacement totally
destroy the inhibition character of known strong PGI
inhibitors.35;36 In the case of the R5P to Ru5P isomeri-
zation catalyzed by spinach RPI, our study shows that
this is not the case. Therefore, synthesis of the new potent
and hydrolytically stable competitive inhibitor 2 appears
very promising for the future development of stable and
species-specific RPI inhibitors of therapeutic interest.
ꢀ
22. Le Marechal, P.; Froussios, C.; Level, M.; Azerad, R.
Carbohydr. Res. 1981, 94, 1–10.
23. Selected data for compound 8: 13C NMR (90 MHz,
CD3OD) d ¼ 138:7–138.4 (C-12, C-120), 129.4 (C-10, C-
100), 129.2 (C-11, C-110), 128.9 (C-9, C-90), 107.8 (C-1),
88.6 (C-2), 88.0 (C-3), 82.8 (d, C-4, J ¼ 18 Hz), 73.1 and
72.8 (C-8, C-80), 55.0 (C-7), 28.7 (C-5), 26.7 (d, C-6,
J ¼ 135 Hz). 31P NMR (CD3OD) d ¼ 26:3.
24. Selected data for compound 9: 13C NMR (50 MHz,
CD3OD) d ¼ 109:1 (C-1a), 102.9 (C-1b), 84.5 (d, C-4a,
J ¼ 18 Hz), 82.9 (d, C-4b, J ¼ 18 Hz), 82.3 (C-2a), 80.8 (C-
3a), 78.7 (C-2b), 77.5 (C-3b), 55.8 (C-7b), 55.6 (C-7a), 29.5
(C-5b), 27.7 (d, C-5a, J ¼ 3 Hz), 24.7 (d, C-6a, C-6b,
J ¼ 135 Hz). 31P NMR (CD3OD) d ¼ 29:2 (Pa), 28.9 (Pb).
25. Chirgwin, J. N.; Noltmann, E. A. J. Biol. Chem. 1975, 250,
7272–7276.
Acknowledgements
ꢁ
The Ministere de l’Education Nationale et de la
Recherche (E.B.) is gratefully acknowledged for finan-
cial support (2001–2004).
ꢀ
26. Hardre, R.; Bonnette, C.; Salmon, L.; Gaudemer, A.
Bioorg. Med. Chem. Lett. 1998, 8, 3435–3438.
27. Hendriks, H. E. J.; Kuster, B. F. M.; Marin, G. B.
Carbohydr. Res. 1991, 214, 71–85.
References and notes
1. Woodruff, W. W.; Wolfenden, R. J. Biol. Chem. 1979, 254,
5866–5867.
2. Burgos, E.; Salmon, L. Tetrahedron Lett. 2004, 45, 753–
756.
3. Engel, R. Chem. Rev. 1977, 77, 349–367.
4. Wiemer, D. F. Tetrahedron 1997, 53, 16609–16644.
5. Le Camus, C.; Badet-Denisot, M.-A.; Badet, B. Tetrahe-
dron Lett. 1998, 39, 2571–2572.
6. Arth, H.-L.; Fessner, W.-D. Carbohydr. Res. 1998, 305,
313–321.
7. Hanessian, S.; Rogel, O. J. Org. Chem. 2000, 65, 2667–
2674.
8. Berkowitz, D. B.; Bose, M.; Pfannenstiel, T. J.; Doukov,
T. J. Org. Chem. 2000, 65, 4498–4508.
9. Pasti, C.; Rinaldi, E.; Cervellati, C.; Dallocchio, F.;
28. El-Subbagh, H. I.; Racha, S.; Abushanab, E.; Panzica, R.
P. J. Org. Chem. 1996, 61, 890–894.
28
29. Selected data for compound 11: ½aꢀ þ10.1 (c 0.97,
D
CH3OH). IR mmax (cmÀ1) (KBr): 3394 (OH), 1743 (CO),
1034 (OC, PO). 1H NMR (250 MHz, CDCl3) d ¼ 4:21–
4.19 (d, 1H, H-1, J ¼ 4 Hz), 3.92–3.82 (m, 1H, H-2), 3.79
(s, 3H, H-6), 3.72 (d, 6H, H-5, J ¼ 11 Hz), 2.03–1.75 (m,
4H, H-3, H-4). 13C NMR (90 MHz, CDCl3) d ¼ 173:2 (C-
1), 74.6 (C-2), 73.1 (d, C-3, J ¼ 16 Hz), 52.8 (d, C-6,
J ¼ 6 Hz), 52.5 (C-7), 25.0 (d, C-4, J ¼ 3 Hz), 20.8 (d, C-5,
J ¼ 142 Hz). 31P NMR (CDCl3) d ¼ 35:9. MS (positive-
ion electrospray): m=z (%) 197 [MÀ2OCH3þ3Hþ] (6), 257
[MþHþ] (13), 279 [MþNaþ] (100). HRMS (positive-ion
electrospray): calcd for C8H17O7PNa (MþNaþ) 279.0610,
found 279.0608.
28
ꢀ
Hardre, R.; Salmon, L.; Hanau, S. Bioorg. Med. Chem.
2003, 11, 1207–1214.
30. Selected data for compound 12: ½aꢀ þ2.8 (c 1.20,
D
CH3OH). IR mmax (cmÀ1) (KBr): 3416 (OH), 1739 (CO),
1028 (OC, PO). 1H NMR (250 MHz, CDCl3) d ¼ 4:26–
4.20 (m, 1H, H-1), 3.76 (d, 6H, H-4, J ¼ 7 Hz), 3.70 (s, 3H,
H-5), 2.20–1.84 (m, 4H, H-2, H-3). 13C NMR (90 MHz,
CDCl3) d ¼ 174:8 (C-1), 70.3 (d, C-2, J ¼ 17 Hz), 52.8 (d,
C-5, J ¼ 7 Hz), 52.7 (C-6), 27.5 (d, C-3, J ¼ 4 Hz), 20.4 (d,
C-4, J ¼ 142 Hz). 31P NMR (CDCl3) d ¼ 34:8. MS
(positive-ion electrospray): m=z (%) 167 [MÀ2OCH3 þ
3Hþ] (17), 227 [MþHþ] (10), 249 [MþNaþ] (77), 293
(100). HRMS (positive-ion electrospray): calcd for
10. Hirsch, G.; Grosdemange-Billiard, C.; Trisch, D.; Roh-
mer, M. Tetrahedron Lett. 2004, 45, 519–521.
11. Guanti, G.; Banfi, L.; Zannetti, M. T. Tetrahedron Lett.
2000, 41, 3181–3185.
12. Dardonville, C.; Rinaldi, E.; Hanau, S.; Barrett, M. P.;
Brun, R.; Gilbert, I. H. Bioorg. Med. Chem. 2003, 11, 31–
42.
13. Le Camus, C.; Chassagne, A.; Badet-Denisot, M.-A.;
Badet, B. Tetrahedron Lett. 1998, 39, 287–288.
14. Le Camus, C. Ph.D. Thesis, Universite Rene Descartes,
C7H15O6PNa (MþNaþ) 249.0504, found 249.0506.
ꢀ
ꢀ
28
Paris (France), 1998.
15. Unger, F. M.; Stix, D.; Moderndorfer, E.; Hammersch-
31. Selected data for compound 2: ½aꢀ þ8.5 (c 1.09, H2O). IR
D
mmax (cmÀ1) (KBr): 3406 (OH), 1682 (CO), 1027 (OC, PO).
1H NMR (250 MHz, D2O) d ¼ 4:23 (d, 1H, H-1,
J ¼ 4 Hz), 3.90–3.80 (m, 1H, H-2), 1.81–1.54 (m, 4H,
H-3, H-4). 13C NMR (50 MHz, D2O) d ¼ 176:9 (C-1), 74.8
(C-2), 74.0 (d, C-3, J ¼ 18 Hz), 26.3 (C-4), 25.0 (d, C-5,
€
mid, F. Carbohydr. Res. 1978, 67, 349–356.
16. Zinner, H.; Braudner, H.; Reubarz, G. Chem. Ber. 1956, 3,
800–813.
17. Green, J. W.; Pacsu, E. J. Am. Chem. Soc. 1937, 59, 1205–
1210.
J ¼ 133 Hz). 31P NM R (DO) d ¼ 28:9.
2

E. Burgos, L. Salmon / Tetrahedron Letters 45 (2004) 3465–3469
3469
28
D
32. Selected data for compound 10: ½aꢀ þ6.6 (c 1.04, H2O).
34. Nosoh, Y.; Sekiguchi, T. Protein Stability and Stabiliza-
tion through Protein Engineering; Ellis Horwood; New
York, London, Sydney, Tokyo, Singapore; 1991. p 86.
ꢀ
35. Sengmany, S. Ph.D. Thesis, Universite Paris-Sud XI,
Orsay (France), 2003.
IR mmax (cmÀ1) (KBr): 3402 (OH), 1676 (CO), 1056 (OC,
PO). 1H NMR (250 MHz, D2O) d ¼ 4:21–4.16 (m, 1H,
H-1), 21.0–1.50 (m, 4H, H-2, H-3). 13C NMR (50 MHz,
D2O) d ¼ 179:8 (C-1), 71.4 (d, C-2, J ¼ 18 Hz), 27.8 (d, C-
3, J ¼ 4 Hz), 22.8 (d, C-4, J ¼ 137 Hz). 31P NM R (DO)
ꢀ
36. Badet, B.; Guenard, D.; Badet-Denisot, M.-A.; Seng-
2
d ¼ 27:7.
many, S. International Burgenstock Symposium ‘Fluorine
in Life Sciences’, Burgenstock (Switzerland), July
2003.
33. Knowles, F. C.; Pon, M. K.; Pon, N. G. Anal. Biochem.
1969, 29, 40–47.