Synthesis of C-glycosides related to glycero-β-d-manno-heptoses

Article abstract of DOI:10.1016/j.tetasy.2004.11.065

Reducing heptopyranoses of the d-glycero-d-manno- and l-glycero-d-manno- configuration were converted in good overall yields into β-anomeric C-glycosides via condensation with pentane-2,4-dione, followed by sodium methoxide-induced enrichment of the β-anomeric products and subsequent O-acetylation. The resulting 2-oxo-propyl glycosides were further transformed into separable ～1:1 diastereomeric mixtures of (S)-and (R)-2-hydroxy derivatives. The configuration of the additional stereogenic centre was assigned on the basis of NMR data obtained from the corresponding Dale-Mosher esters. Finally, phosphorylation of the d-glycero-d-manno-heptose analogues using the phosphoramidite procedure and deprotection furnished the (S)- and (R)-2-phosphate derivatives in good yields. The compounds serve as substrate analogues for enzymes involved in bacterial ADP heptose biosynthesis and glycosyl transfer reactions.

Full text of DOI:10.1016/j.tetasy.2004.11.065

Tetrahedron:
Asymmetry
Tetrahedron: Asymmetry 16 (2005) 167–175
Synthesis of C-glycosides related to glycero-b-D-manno-heptoses
Andrea Graziani, Hassan Amer, Alla Zamyatina, Andreas Hofinger and Paul Kosma*
Department of Chemistry, University of Natural Resources and Applied Life Sciences, Muthgasse 18, A-1190 Wien, Austria
Received 28 October 2004; accepted 24 November 2004
Abstract—Reducing heptopyranoses of the D-glycero-D-manno- and L-glycero-D-manno-configuration were converted in good over-
all yields into b-anomeric C-glycosides via condensation with pentane-2,4-dione, followed by sodium methoxide-induced enrichment
of the b-anomeric products and subsequent O-acetylation. The resulting 2-oxo-propyl glycosides were further transformed into sep-
arable ꢀ1:1 diastereomeric mixtures of (S)-and (R)-2-hydroxy derivatives. The configuration of the additional stereogenic centre was
assigned on the basis of NMR data obtained from the corresponding Dale–Mosher esters. Finally, phosphorylation of the D-gly-
cero-D-manno-heptose analogues using the phosphoramidite procedure and deprotection furnished the (S)- and (R)-2-phosphate
derivatives in good yields. The compounds serve as substrate analogues for enzymes involved in bacterial ADP heptose biosynthesis
and glycosyl transfer reactions.
ꢀ 2004 Elsevier Ltd. All rights reserved.
1. Introduction
ase reaction inverts the stereochemistry at carbon 6 of
the precursor ADP-D-glycero-b-D-manno-heptose to
provide ADP-L-glycero-b-D-manno-heptose—the com-
mon substrate for inner core enterobacterial heptosyl
transferases (Fig. 1).7,8 Furthermore, crystal structures
of the ADP-L-glycero-b-D-manno-heptose 6-epimerase
and of ADP-L-glycero-b-D-manno-heptose transferase
II from Escherichia coli have recently been reported.9,10
So far, structural data of these enzymes complexed to
appropriate substrates have not been obtained. ADP
heptopyranoses of the b-anomeric configuration are
unstable due to neighbouring group participation of
the axial 2-OH group resulting in the formation of hep-
tose 1,2-cyclo-phosphate and release of AMP.11 To
overcome the inherent hydrolytic lability of the ADP
heptoses we set out to synthesize stable C-glycosides in
the b-anomeric configuration to be used as versatile
building blocks for the synthesis of substrate analogues.
Lipopolysaccharides (LPS) are structurally complex
amphipathic and microheterogeneous glycolipids, which
are essential components of the outer membrane of
Gram-negative bacteria.1 In many cases, lipopolysac-
charides display a tripartite structure, comprising lipid
A with a bisphosphorylated and acylated glucosamine
disaccharide backbone, the core region containing 3-
deoxy-D-manno-oct-2-ulosonic acid (Kdo), heptoses of
the L-glycero-D-manno- and D-glycero-D-manno- config-
uration and a regular polysaccharide chain harbouring
the O-antigen.2 Since the higher-carbon sugars do not
occur in mammalian systems, the inhibition of the bio-
synthesis of the nucleotide-activated sugars and the
respective glycosyl transferase reactions is regarded as
an attractive target for the design of novel antimicrobial
agents.
The biosynthesis of the nucleotide-activated heptoses of
the D-glycero- and L-glycero-D-manno- configuration has
recently been fully elucidated.3,4 Heptoses transferred to
the inner core of Enterobacteriaceae—but also onto
hitherto structurally not characterized bacterial adhe-
sins5—are activated as ADP-linked sugars.6 An epimer-
2. Results and discussion
The chemical synthesis of C-glycosides has been devel-
oped considerably over the past few years.12 The con-
struction of C-glycosides in the b-manno-configured
cases, however, has met with difficulties, similar to their
O-glycosidic counterparts. By contrast, the direct assem-
bly of C-glycosides by aqueous Knoevenagel-type con-
densation of unprotected sugars with b-dicarbonyl
compounds has been reported to proceed with
*
Corresponding author. Tel.: +43 1 36006 6055; fax: +43 1 36006
6059; e-mail: paul.kosma@boku.ac.at
0957-4166/$ - see front matter ꢀ 2004 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tetasy.2004.11.065

168
A. Graziani et al. / Tetrahedron: Asymmetry 16 (2005) 167–175
D-glycero-β-D-manno-heptose 1-phosphate
HldE
NH2
NH2
N
OH
N
N
OH
N
N
N
N
HO
O
HO
O
P
OH
O
O
O
P
OH
O
HO
HO
N
P
O
HO
HO
P
_
O
O
O
O
O
O
O
_ O
O
_
O
O
_
HldD
HO OH
HO OH
WaaC
WaaC, WaaF, WaaQ
Figure 1. Structure of ADP heptoses and enzymes involved in heptose activation and heptosyl transfer reactions. HldE: Heptose 1-phosphate
adenylyltransferase; HldD: ADP-D-glycero-b-D-manno-heptose epimerase; WaaC, WaaF, WaaQ: inner core ADP-heptosyl transferases.
pronounced b-anomeric stereoselectivity.13–15 Further-
more, subsequent alkali-induced anomeric epimeriza-
tion gave b-20-carbonylalkyl glycosides in high yield.
These compounds may now be exploited for further
transformation and for coupling reactions to mono- or
diphosphonucleoside derivatives. Reaction of D-gly-
cero-D-manno-heptose16 with an aqueous solution of
pentane-2,4-dione gave an anomeric mixture of the a-
and b-configured C-glycosidic ketones 2 and 3 in a 2:1
ratio and two other minor components. The assign-
dibenzyl-N,N-diisopropyl-phosphoramidite/1H-tetrazole
and subsequent oxidation with tert-BuOOH in 70%
20
D
yield.18 Again, the ½aŠ values (+2.5 for 7, À8 for 10)
were consistent with the (S)- and (R)-assignment,
respectively. Deprotection of the penta-O-acetyl deriva-
tives 5 and 8 under alkaline conditions furnished the b-
C-glycosides 11 and 12 in high yield, respectively.
Deprotection of the phosphotriester derivatives 7 and
10 was performed in two steps and in 90% yield by
hydrogenolysis of the benzyl groups with 10% Pd–car-
bon followed by removal of the acetyl groups with tri-
ethylamine in aqueous MeOH. NMR evidence for the
presence of the 2-phosphate was provided by the down-
1
ments were based on the H NMR chemical shift of
H-8, which was shifted upfield for the b-anomeric hepto-
pyranose derivative (3.36 ppm) in comparison to the a-
anomer (3.54 ppm). In order to enrich the b-isomer 3,
the mixture was treated with methanolic sodium meth-
oxide, which also led to a conversion of the higher-run-
ning by-products into the target compound 3. Following
acetylation with acetic anhydride in pyridine to facilitate
chromatographic separation, the penta-O-acetyl deriva-
tive 4 was obtained in 65% overall yield. Deprotection of
4 by treatment with triethylamine in aqueous MeOH
furnished the dec-2-ulopyranose derivative 3 in 92%
yield.
1
field shift of the H NMR signal H-2 and the 31P chem-
ical shifts (d 2.53 for 14, d 2.54 for 16). The 2-O-
phosphoryl group present in compounds 14 and 16
may be regarded as mimic of the diphosphate bridge
in the nucleotide sugar and—although lacking the
charged moiety of the glycosyl phosphate—could pro-
vide a proper formal distance to fit into the binding site
of the glycosyl transferase, an important aspect to main-
tain binding potency of synthetic inhibitors.19
In addition to the analogues of D-glycero-D-manno-hep-
tose, C-glycosides of the L-glycero-D-manno- configura-
Reduction of the b-C-glycoside derivative 4 with bor-
ane–ammonia furnished a ꢀ1:1.2 mixture of the diaste-
reomeric alcohols 5 and 8 (90% yield), which could be
partially separated by column chromatography. In order
to assign the stereochemistry at the new stereogenic
centre, the mixture of compounds being enriched in
one diastereoisomer was converted into the (S)- and
(R)-2-methoxy-2-phenyl-3-trifluoro-1-propanoic esters17
as the Mosher ester pairs 6a, 9a and 6b, 9b, respectively.
According to Mosherꢀs rules, the higher running deriva-
tive 5 was assigned as the (S)-configured derivative
tion were prepared in
a similar fashion. Thus,
condensation of 1720 with pentane-2,4-dione proceeded
in good yield to afford a complex mixture containing
the anomeric 2-oxo-propyl heptopyranosides 18 and
20. Acetylation of the mixture afforded 19 and 21, which
were partially separated and characterized. Measure-
ments of the heteronuclear coupling constant JC4,H4
were consistent with the assignment of the anomeric
configuration and showed 152 Hz for the a-anomer 19
and 142 Hz for the b-anomer 21. Similar to the D-gly-
cero-D-manno derivatives, the proportion of 21 could
be substantially increased via alkaline epimerization of
the crude reaction mixture containing 18 and 20 with so-
dium methoxide and O-acetylation to give the b-anomer
21 in 56% yield.21 Deprotection furnished the b-C-glyco-
side 20 in 98% yield (Scheme 2). Reduction of the keto-
group with NaBH4 gave the (S)- and (R)-alcohols 22
and 24 in a ꢀ10:9 ratio, which were more readily sepa-
rable in comparison to 5 and 8. The stereochemical
assignments were based on the similarity of 13C NMR
chemical shifts for C-1 and C-3 with those for 5 and 8.
1
based on the H NMR chemical shifts observed in the
(S)-MTPA esters for the methyl group of the decitol
moiety of 6a (d 1.36) in comparison with the value ob-
served for 9a (d 1.28), whereas the (R)-MTPA esters
6b, 9b displayed an inverse relation of chemical shifts
(d 1.29 for 6b, d 1.36 for 9b). In addition, the dextroro-
tatory value measured for the specific rotation of diaste-
reoisomer 5 (+2) versus that for compound 8 (À19) is
consistent with the assignments (Scheme 1). Better sepa-
ration of the mixture was achieved following phosphityl-
ation using the phosphoramidite procedure with

A. Graziani et al. / Tetrahedron: Asymmetry 16 (2005) 167–175
169
OR
OH
OH
RO
RO
OR
O
HO
OH
O
HO
OH
O
a)
HO
HO
HO
HO
+
RO
OH
O
3 R =
H
2
1
b)
4 R = Ac
O
c)
OH
OAc
OAc
OH
d)
g)
HO
AcO
AcO
OH
O
AcO
AcO
OAc
O
OAc
O
d)
HO
OH
O
HO
HO
HO
HO
AcO
AcO
OH
OR
OR
OH
8
R = H
11
12
5
R =
H
e)
e)
9a R = (S)-MTPA
9b R = (R)-MTPA
6a R = (S)-MTPA
6b R = (R)-MTPA
f)
f)
g)
10 R = (BnO)2P=O
7
R = (BnO)2P=O
h)
h)
OR
OR
RO
OR
O
RO
OR
O
RO
RO
RO
RO
OH
OH
OH
O
CF3
MeO
O
MTPA =
P
P
OH
13 R = Ac
15 R = Ac
16 R =
d)
O
d)
14 R =
H
O
H
O
Scheme 1. Synthesis of D-glycero-D-manno-heptopyranosyl analogues. Reagents and conditions: (a) aq NaHCO3, pentane-2,4-dione; (b) NaOMe,
MeOH; then Ac2O, pyridine, 65% for 4; (c) NH3–BH3, MeOH, 90%; (d) Et3N, aq MeOH, 92%; (e) (S)-MTPA-Cl, pyridine; (f) (R)-MTPA-Cl,
pyridine; (g) N,N-(iPr)2NP(OBn)2, 1H-tetrazole, MeCN–CH2Cl2, then t-BuOOH, 38% for 10, 31% for 17; (h) 10% Pd–C, MeOH, 95%.
´
Zemplen de-O-acetylation of 22 and 24 afforded the
characteristics as well as the values for the specific rota-
tion [À9 for the 2-(S)-configured alcohol versus À46 for
the (R)-isomer; the value measured for the known
fully deprotected 4,8-anhydro-decitol derivatives 23
and 25 in high yield, respectively. The NMR-spectral
OH
HO
HO
OH
O
OH
HO
17
a); b)
OR
OR
RO
OR
O
RO
OR
O
RO
RO
RO
RO
+
O
20 R =
H
18 R =
H
c)
c)
d)
21 R = Ac
19 R = Ac
O
e)
OR
OR
RO
RO
RO
OR
O
OR
O
RO
RO
RO
OH
OH
22 R = Ac
24 R = Ac
25 R =
d)
d)
23 R =
H
H
Scheme 2. Synthesis of L-glycero-D-manno-heptopyranosyl analogues. Reagents and conditions: (a) aq NaHCO3, pentane-2,4-dione; (b) MeONa,
MeOH; (c) Ac2O, pyridine, DMAP, 56% for 21 (three steps); (d) NaOMe, MeOH, 98% for 20, 85% for 23, 97% for 25; (e) NaBH4, MeOH, 94%.

170
A. Graziani et al. / Tetrahedron: Asymmetry 16 (2005) 167–175
methyl L-glycero-b-D-manno-heptopyranoside21 is À40
and for (S)-1,2-propanediol +16] were in agreement with
the previous assignments.
(113 mg, 0.54 mmol), NaHCO3 (69 mg, 0.82 mmol)
and pentane-2,4-dione (68 lL, 0.65 mmol) in water
(10mL) was stirred at 90 ꢁC for 14 h. The solution
was diluted with water and neutralized with Dowex 50
resin (H+ form). The resin was filtered off, and the fil-
trate was lyophilized. Rf 0.16 (4:2:0.25 EtOAc/2-propa-
nol/water); 1H NMR (D2O) for 2: d 4.36 (ddd, 1H,
Conversion of the analogues into nucleoside deriva-
tives and biological results will be reported in due
course.
3
H-4), 4.05 (ddd, 1H, J9,8 = 5.0Hz, H-9), 3.87 (t, 1H,
3J7,6 = 3J7,8 = 7.7 Hz, H-7), 3.82 (m, 2H, H-5, H-6),
3.76 (dd, 1H, J9,10a = 3.3 Hz, H-10a) 3.62 (dd, 1H,
3
3. Conclusion
2
3J9,10b = 7.2 Hz, J10a,10b = 12.0Hz, H-10b), 3.54 (dd,
1H, H-8), 3.02 (dd, 1H, J3a,3b = 17.0Hz, J3a,4 =
2
3
The condensation of pentane-2,4-dione with reducing
glycero-D-manno-heptoses followed by alkaline epi-
merization provides an easy access to b-configured
C-alkylcarbonyl glycosides as educts for further trans-
formations, such as reduction to give diastereomeric
alcohols and further elaboration into isosteric analogues
of nucleotide-activated sugars.
3
9.0Hz, H-3a), 2.85 (dd, 1H, J3b,4 = 4.9 Hz, H-3b) and
2.25 (s, 3H, H-1); 13C NMR (D2O): d 213.04 (C-2),
75.73 (C-8), 73.50(C-4), 72.10(C-9), 71.45 (C-5),
70.86 (C-6), 68.68 (C-7), 62.92 (C-10), 45.24 (C-3) and
30.63 (C-1). The mixture was dissolved in dry MeOH
(50mL) and stirred with 1.3 M methanolic NaOMe
(2 mL) for 12 h at room temperature. The solution
was concentrated and the residue (110mg) was dissolved
in dry pyridine (10mL). Acetic anhydride was added
(2.0mL, 21.2 mmol) at 0 ꢁC and the solution was stirred
for 12 h at room temperature. MeOH (1 mL) was added,
and the mixture was diluted with ethyl acetate (200 mL).
The organic phase was washed sequentially with ice-cold
6 M HCl, water, satd aq NaHCO3, water and brine and
dried (Na2SO4). The solution was concentrated and the
residue was purified on silica gel (1:9 n-hexane/diethyl
4. Experimental
4.1. General methods
Column chromatography was performed on silica gel 60
(230–400 mesh, Merck), HPLC was performed on silica
gel 60(10 lm). Anion-exchange chromatography was
performed on a strong anion-exchange resin (Bio-Rad,
5 mL cartridge, HCOÀ2 form). Reactions were monitored
ether), which afforded 4 as a pallid yellow syrup. Yield:
20
D
3
by TLC on silica gel 60F
precoated glass plates
161 mg (65% for three steps); ½aŠ ¼ À10( c 0.9, CHCl3);
254
(Merck) or on silica gel 60F 254 HPTLC precoated glass
plates with 2.5 cm concentration zone (Merck); spots
were visualised by spraying with anisaldehyde–H2SO4;
phosphorus-containing compounds were additionally
detected with a molybdate solution [0.02 M solution of
ammonium cerium(IV)sulfate dihydrate and ammonium
molybdate(VI)tetrahydrate in aqueous H2SO4]. Concen-
tration of solutions was performed at reduced pressure
1H NMR: d 5.30(dd, 1H, J5,4 = 1.0Hz, H-5), 5.21 (t,
3
1H, J7,8 = 3J7,6 = 9.7 Hz, H-7), 5.12 (ddd, 1H,
3
3J9,8 = 3.0Hz, H-9), 5.07 (dd, 1H, J6,5 = 3.5 Hz, H-6),
4.34 (dd, 1H, J10a,9 = 3.7 Hz, H-10a), 4.21 (dd, 1H,
3
2
3J10b,9 = 7.3 Hz, J10b,10a = 12.0Hz, H-10b), 4.13 (ddd,
1H, H-4), 3.68 (dd, 1H, H-8), 2.71 (dd, 1H,
2
2J3a,4 = 8.0Hz, H-3a), 2.41 (dd, 1H, J3b,4 = 5.0Hz,
2J3a,3b = 17.0 Hz, H-3b), 2.16, 2.06, 2.05, 2.04, 1.96 (5s,
15H, CH3, Ac), 2.14 (s, 3H, CH3); 13C NMR (CDCl3)
d = 204.61 (C-2), 171.04, 170.74, 170.35, 170.25, 170.22
at temperatures <25 ꢁC. Optical rotations were mea-
20
sured with a Perkin–Elmer 243 B polarimeter. ½aŠ val-
D
ues are given in units of 10À1 deg cm3 gÀ1. NMR spectra
were recorded at 297 K in CDCl3 (unless stated other-
wise) with a Bruker DPX 300 spectrometer (1H at
300.13 MHz, 13C at 75.47 MHz and 31P at
121.50MHz) using standard Bruker NMR software.
1H NMR spectra were referenced to tetramethylsilane
or 2,2-dimethyl-2-silapentane-5-sulfonic acid. 13C
NMR spectra were referenced to chloroform (d 77.00)
or external 1,4-dioxane (d 67.40). 31P NMR spectra were
referenced externally to 85% aq H3PO4 (d 0.0). Elemen-
tal analyses were provided by Dr. J. Theiner, Mikro-
(5C,
CO,
Ac),
77.57
(C-8),
73.24
(C-4,
JC-4,H-4 = 143 Hz), 72.51 (C-6), 70.69 (C-9), 70.17 (C-
5), 66.89 (C-7), 62.01 (C-10), 44.40 (C-3), 31.01 (C-1),
21.25, 21.09, 21.06, 20.91 (5C, CH3, Ac); Anal. Calcd
for C20H28O12 (460.43): C, 52.17; H, 6.13. Found: C,
52.10; H, 6.24.
4.1.2. 4,8-Anhydro-1,3-dideoxy-D-erythro-D-galacto-dec-
2-ulose 3. A solution of 4 (30 mg, 0.065 mmol) in 3:2:1
MeOH–water–Et3N (2 mL) was stirred at room temper-
ature for 3 h. The reaction mixture was evaporated and
purified by a flash chromatography (4:2:0.25 ethyl-
analytisches Laboratorium, Institut fur Physikalische
¨
Chemie, Universita¨t Wien. TOF-ES-MS spectra were re-
corded on a Waters Micromass Q-TOF Ultima Global
instrument. MALDI-TOF-MS spectra were recorded
acetate/2-propanol/water) to give 3 (15 mg, 92%,
20
D
0.060 mmol) as a colourless syrup. ½aŠ ¼ À13 (c 0.7,
H2O); 1H NMR (D2O) for 3: d 3.99 (ddd, 1H,
3
on
a
Thermo-BioAnalysis Dynamo MALDI-TOF
3J5,4 = 1.0Hz, H-4), 3.95 (ddd, 1H, J9,8 = 3.6 Hz,
3
instrument in the positive ion mode with 2% 2,5-dihydr-
oxybenzoic acid as matrix. Melting points were deter-
mined with a Kofler hot stage microscope and are
uncorrected.
3J9,10b = 7.2 Hz, H-9), 3.83 (dd, 1H, J5,6 = 3.0Hz,
H-5), 3.73 (dd, 1H, J9,10a = 3.5 Hz, H-10a), 3.68 (t,
3
1H, 3J7,6 = 3J7,8 = 9.5 Hz, H-7), 3.66 (dd, 1H,
2J10a,10b = 12.0Hz, H-10b), 3.65 (dd, 1H, H-6), 3.36
(dd, 1H, H-8), 2.91 (dd, 1H, J3a,3b = 17.0Hz,
2
3
4.1.1. 5,6,7,9,10-Penta-O-acetyl-4,8-anhydro-1,3-dide-
oxy-D-erythro-D-galacto-dec-2-ulose 4. A solution of 1
3J3a,4 = 8.5 Hz, H-3a), 2.75 (dd, 1H, J3b,4 = 4.5 Hz, H-
3b) and 2.24 (s, 3H, H-1); 13C NMR (D2O): d 213.38

A. Graziani et al. / Tetrahedron: Asymmetry 16 (2005) 167–175
171
(C-2), 80.40 (C-8), 74.67, 74.59 (C-4, C-6), 72.66 (C-9),
70.98 (C-5), 68.27 (C-7), 62.29 (C-10), 44.83 (C-3) and
30.19 (C-1). Anal. Calcd for C10H18O7ÆH2O: C, 44.77;
H, 7.51. Found: C, 45.36; H, 7.61.
Conversion into Dale–Mosher esters 6b and 9b: A solu-
tion of (R)-MTPA chloride (15 lL, 80 lmol) in dry pyr-
idine (1 mL) was charged with CCl4. The mixture
containing 5 and 8 (17 mg, 0.037 mmol, enriched with
5) dissolved in 2 mL dry pyridine was added and treated
1
4.1.3. 5,6,7,9,10-Penta-O-acetyl-4,8-anhydro-1,3-dideoxy-
D-ribo-L-manno-decitol 5 and 5,6,7,9,10-penta-O-acetyl-
as described for 6a and 9a. H NMR (MeOD) for 6b:
d 1.98 (m, H-3a), 1.68 (m, H-3b), 1.29 (d, 3H,
4,8-anhydro-1,3-dideoxy-D-ribo-L-gluco-decitol
8.
A
3J1,2 = 6.3 Hz, H-1); data for 9b: d 1.80(m, H-3a),
1.52 (m, H-3b), 1.36 (d, 3H, J1,2 = 6.2 Hz, H-1).
3
solution of 4 (200 mg, 0.43 mmol) in dry MeOH
(15 mL) was treated with borane–ammonia (23 mg,
0.74 mmol) at 0 ꢁC. Then the mixture was stirred under
Ar for 15 h at rt. The solution was concentrated to give
a mixture of diastereomers (180mg, 90%), which was di-
rectly used for the next step. Alternatively, the diastereo-
isomers can be separated by silica gel chromatography
using 7:3 diethyl ether/CH2Cl2 as eluant, followed by sev-
eral HPLC steps. Data for 5:Rf 0.20 (1:1, diethyl ether/
4.1.4. 5,6,7,9,10-Penta-O-acetyl-4,8-anhydro-2-O-[bis(benz-
yloxy)phosphoryl]-1,3-dideoxy-D-ribo-L-manno-decitol 7
and 5,6,7,9,10-penta-O-acetyl-4,8-anhydro-2-O-[bis(benz-
yloxy)phosphoryl]-1,3-dideoxy-D-ribo-L-gluco-decitol 10.
The diastereomeric mixture of 5 and 8 (134 mg,
0.29 mmol) and dibenzyl-N,N-diisopropylphosphorami-
dite (0.234 mL, 0.72 mmol) were dried by repeated evap-
oration with dry toluene (3 · 10mL) and then under
diminished pressure for 10h. Then the flask was charged
with CH2Cl2 (5 mL), a solution of 1H-tetrazole (61 mg,
0.87 mmol) in dry CH3CN (3 mL) was added and the mix-
ture was stirred at room temperature for 3 h under N2.
Monitoring of the reaction by TLC showed the formation
of intermediate phosphite triesters (Rf 0.54; 1:1, n-hexane/
EtOAc). The reaction mixture containing phosphite tri-
esters was cooled to 0 ꢁC and a solution of t-BuOOH
(72 lL of an 80% solution in di-tert-butyl peroxide) in
CH2Cl2 (3 mL) was gradually added (ꢀ20min). The reac-
tion mixture was warmed to room temperature and stir-
red for 12 h. The solvent was evaporated using a stream
of N2. The residue was redissolved in diethyl ether and
washed sequentially with saturated NaHCO3–water and
brine. The organic phase was dried (Na2SO4) and concen-
trated. The phosphates were separated by chromatogra-
phy on silica gel (several columns with 1:9 n-hexane/
diethyl ether and 1:1 EtOAc/n-hexane) and final HPLC
purification to give 10 (79 mg, 38%, 0.10 mmol) as a
20
1
CH2Cl2); ½aŠ ¼ þ2 (c 1.0, MeOH); H NMR (MeOD):
D
3
3
d 5.37 (dd, 1H, J5,6 = 3.3 Hz, J5,4 = 1.0Hz, H-5),
5.20(dd, 1H, J7,6 = 9.8 Hz, H-7), 5.13 (m, 1H, H-9),
3
5.10(dd, 1H, H-6), 4.39 (dd, 1H, 3J10a,9 = 3.5 Hz,
2J10a,10b = 12.0Hz, H-10a), 4.20 (dd, 1H,
3J10b,9
=
3
7.5 Hz, H-10b), 3.91 (ddd, 1H, J4,3b = 6.0Hz,
3J4,3a = 7.5 Hz, H-4), 3.80(m, 1H, H-2), 3.79 (dd, 1H,
3J8,9 = 3.0Hz, J8,7 = 9.8 Hz, H-8), 2.15, 2.06, 2.05,
2.02, 1.94 (5s, 15H, CH3, Ac) 1.77 (ddd, 1H,
3
3J3a,2 = 6.5 Hz, J3a,3b = 14.0Hz, H-3a), 1.49 (ddd, 1H,
2
3J3b,2 = 5.5 Hz, H-3b), 1.16 (d, 3H, 3J1,2 = 6.2 Hz, CH3);
13C NMR (MeOD): d 172.40, 172.23, 171.72, 171.68,
171.53 (5C, CO, Ac), 78.26 (C-8), 75.69 (C-4), 73.99 (C-
6), 71.84 (C-9), 71.05 (C-5), 68.18 (C-7), 65.38 (C-2),
62.84 (C-10), 40.31 (C-3), 23.26 (C-1), 20.79, 20.71,
20.63, 20.53, 20.49 (5C, CH3, Ac). Data for 8: Rf
20
D
0.14 (1:1, diethyl ether/CH2Cl2); ½aŠ ¼ À19 (c
1
3
0.5, MeOH); H NMR (MeOD): d 5.27 (dd, 1H, J5,6
3.3 Hz, J5,4 = 0.9 Hz, H-5), 5.19 (dd, 1H, J7,8
=
=
3
3
9.8 Hz, H-7), 5.13 (m, 1H, H-9), 5.10(dd, 1H,
20
3
1
3J6,7 = 9.8 Hz, H-6), 4.39 (dd, 1H, J10a,9 = 3.5 Hz,
H-10a), 4.20 (dd, 1H, 3J10b,9 = 7.5 Hz, 2J10b,10a = 12.0Hz,
H-10b), 3.93 (ddd, 1H, 3J4,3b = 9.5 Hz, H-4), 3.88 (m, 1H,
colourless syrup, Rf 0.15; ½aŠ ¼ À8 (c 0.7, CHCl3); H
D
NMR (CDCl3): d 7.40–7.30 (m, 10H, Ph), 5.13 (d, 1H,
3J5,6 = 3.5 Hz, H-5), 5.12 (dd, 1H, J7,8 = 9.8 Hz, H-7),
5.10(m, 1H, H-9), 5.05 (d, 2H, JH,P = 8.0Hz, C H2Ph),
3
H-2), 3.78 (dd, 1H, 3J8,9 = 3.0 Hz, H-8), 2.06, 2.05, 2.02,
3
3
2.01, 1.94 (5s, 15H, CH3, Ac), 1.65 (ddd, 1H, J3a,2
3
5.02 (d, 2H, JH,P = 8.0Hz, C H2Ph), 4.86 (dd, 1H,
=
3.4 Hz, 3J3a,4 = 10.0 Hz, 2J3a,3b = 14.0Hz, H-3a),
3J6,7 = 9.8 Hz, H-6), 4.65 (m, 1H, H-2), 4.34 (dd, 1H,
3
2
1.36 (ddd, 1H, J3b,2 = 3.0Hz, H-3b), 1.17 (d, 3H,
3J10a,9 = 3.5 Hz, J10a,10b = 12.0Hz, H-10a), 4.22 (dd,
1H, J10b,9 = 7.5 Hz, H-10b), 3.58 (br d, 1H, J =
3J1,2 = 6.3 Hz, CH3); 13C NMR (MeOD): d 172.43,
172.18, 171.76, 171.68, 171.55 (5C, CO, Ac), 78.13 (C-
8), 74.95 (C-4), 74.09 (C-6), 72.12, 71.99 (C-9, C-5),
68.24 (C-7), 64.93 (C-2), 62.99 (C-10), 41.31 (C-3), 24.20
(C-1), 20.80, 20.72, 20.62, 20.54, 20.51 (5C, CH3, Ac).
3
3
ꢀ9.0Hz, H-4), 3.43 (dd, 1H, J8,9 = 3.0Hz, H-8), 2.16,
2.13, 2.08, 2.04, 1.96 (5s, 15H, CH3, Ac), 1.62 (m, 1H,
3
H-1a), 1.48 (m, H-3b), 1.30(d, 3H, J1,2 = 6.2 Hz, CH3);
13C NMR (CDCl3): d 170.86, 170.56, 170.41, 170.10,
170.02 (5C, CO, Ac), 136.02, 135.66 (2C, Ph), 128.84,
128.77, 128.72, 128.69, 128.64 (10C, Ph), 77.33 (C-8),
Conversion into Dale–Mosher esters 6a and 9a: A solu-
tion of (S)-MTPA chloride (15 lL, 80 lmol) in dry pyr-
idine (1 mL) was charged with CCl4. The mixture
containing 5 and 8 (17 mg, 0.037 mmol, enriched with
5) dissolved in 2 mL of dry pyridine was added and stir-
red for 12 h at room temperature. Diethylamine (12 lL,
0.11 mmol) was added and the suspension was diluted
with ether. The organic phase was extracted with ice-
cold HCl, water, Na2CO3, water, brine, dried (Na2SO4)
3
72.94 (C-4), 72.90(1C, J2,P = 5.8 Hz, C-2), 72.52 (C-6),
70.40, 70.33 (C-5, C-9), 69.39, (1C, JC,P = 6.0Hz,
2
2
CH2Ph), 69.32 (1C, JC,P = 6.0Hz, CH2Ph), 66.62 (C-
3
7), 62.09 (C-10), 39.29 (1C, JC,P = 6.2 Hz, C-3), 22.43
3
(1C, JC,P = 2.3 Hz, C-1), 21.05, 20.91, 20.85, 20.74
(5C, CH3, Ac); 31P NMR (CDCl3): d À0.8; Anal. Calcd
for C34H43O15P (722.67): C, 56.51; H, 6.00. Found: C,
56.49; H, 6.28.
1
and concentrated. H NMR (MeOD) for 6a: d 1.85 (m,
H-3a), 1.65 (m, H-3b), 1.36 (d, 3H, J1,2 = 6.3 Hz, H-1);
3
Further elution gave 7 (65 mg, 31%, 0.09 mmol) as a col-
20
D
1
data for 9a: d 1.85 (m, H-3a), 1.65 (m, H-3b), 1.28 (d,
3H, J1,2 = 6.2 Hz, H-1).
ourless syrup, Rf 0.10; ½aŠ ¼ þ2:5 (c 0.6, CHCl3); H
3
NMR (CDCl3): d 7.37–7.30(m, 1H0 , Ph), 5.27 (dd,

172
A. Graziani et al. / Tetrahedron: Asymmetry 16 (2005) 167–175
3
3
1H, J5,4 = 0.8 Hz, H-5), 5.16 (dd, 1H, J7,6 = 10.0,
3J7,8 = 10.0 Hz, H-7), 5.09 (m, 1H, H-9), 5.05 (d, 2H,
4.1.7. Triethylammonium 5,6,7,9,10-penta-O-acetyl-4,8-
anhydro-1,3-dideoxy-D-ribo-L-manno-decitol 2-phosph-
ate 13. A solution of 7 (40 mg, 0.055 mmol) in dry
MeOH (11 mL) was hydrogenated in the presence of
10% Pd/C (11 mg) for 10 h at atmospheric pressure.
After the completion of the reaction, the catalyst was re-
moved by filtration through a pad of Celite and washed
with MeOH. The combined filtrates were neutralized by
addition of Et3N (9 lL) and concentrated. The residue
was lyophilized from water to give the monotriethylam-
monium salt of 13 (34 mg, 95%) as an amorphous solid.
3JH,P = 8.8 Hz, CH2Ph), 5.04 (d, 2H, JH,P = 8.8 Hz,
CH2Ph), 4.86 (dd, 1H, J6,5 = 4.0Hz, H-6), 4.56 (m,
3
3
3
1H, H-2), 4.36 (dd, 1H, J10a,9 = 3.5 Hz, H-10a), 4.18
3
(dd, 1H, J10b,9 = 7.5 Hz, J10b,10a = 12.0Hz, H-10b),
2
3
3
3.66 (dd, 1H, J4,3b = 6.0Hz, J4,3a = 7.5 Hz, H-4), 3.52
3
(dd, 1H, J8,9 = 2.7 Hz, H-8), 2.12, 2.08, 2.05, 2.04, 1.97
3
(5s, 15H, CH3, Ac), 1.87 (ddd, 1H, J3a,2 = 6.5 Hz,
2J3a,3b = 14.0Hz, H-3a), 1.55 (ddd, 1H, J3b,2 = 5.5 Hz,
3
H-3b), 1.30(d, 3H, 3J1,2 = 6.3 Hz, CH3); 13C NMR
(CDCl3): d 170.76, 170.51, 170.16, 170.04 (5C, CO,
Ac), 136.10, 136.02 (2C, Ph), 128.76, 128.73, 128.20,
128.13 (10C, Ph), 77.35 (C-8), 73.51 (C-4), 72.94 (1C,
3J2,P = 5.8 Hz, C-2), 72.45 (C-6), 70.39 (C-9), 69.81 (C-
Rf 0.75 (5:10:2:2, CHCl3/MeOH/25% aq NH4OH/H2O);
20
½aŠ ¼ þ1 (c 0.2, MeOH); 1H NMR (MeOD): d 5.45 (br
D
s, 1H, H-5), 5.17 (d, 1H, J6,7 = 7.0Hz, H-6) 5.16 (dd,
3
3
1H, J7,8 = 9.0Hz, H-7), 5.12 (m, 1H, H-9), 4.42 (dd,
2
3
2
1H, J10a,9 = 3.4 Hz, J10a,10b = 12.0Hz, H-10a), 4.34
5), 69.52 (1C, JC,P = 6.0Hz, CH2Ph), 69.44 (1C,
2JC,P = 6.0Hz, CH2Ph), 66.62 (C-7), 61.76 (C-10), 37.68
3
(m, 1H, H-2), 4.20(dd, 1H, J10b,9 = 8.2 Hz, H-10b),
3
3
3
4.04 (br t, 1H, H-4), 3.78 (dd, 1H, J8,9 = 3.0Hz,
(1C, JC,P = 6.8 Hz, C-3), 21.32 (1C, JC,P = 2.5 Hz, C-
1), 21.05, 20.90, 20.80, 20.75 (5C, CH3, Ac); 31P NMR
(CDCl3): d À0.9; Anal. Calcd for C34H43O15P (722.67):
C, 56.51; H, 6.00. Found: C, 55.82; H, 6.26.
H-8), 3.16 (q, ꢀ6H, CH2, Et3N), 2.15, 2.06, 2.05, 2.03,
1.95 (5s, 15H, CH3, Ac) 1.84 (m, 1H, H-3a), 1.62 (m,
3
H-3b), 1.33 (d, 3H, J1,2 = 7.2 Hz, CH3), 1.27 (t, ꢀ9H,
CH3, Et3N); 13C NMR (MeOD): d = 171.49, 171.30,
170.77, 170.65, (5C, CO, Ac), 77.26 (C-8), 73.96 (C-4),
73.01 (C-6), 70.87, 70.39 (C-5, C-9), 68.52 (1C,
3J2,P = 5.3 Hz, C-2), 67.44 (C-7), 61.89 (C-10), 46.67
4.1.5. 4,8-Anhydro-1,3-dideoxy-D-ribo-L-manno-decitol
11. A solution of 5 (25 mg, 0.065 mmol) in 3:2:1
MeOH–water–Et3N (2 mL) was stirred at room temper-
ature for 3 h. The reaction mixture was evaporated and
purified by flash chromatography (4:2:0.25 EtOAc/
3
(CH2, Et3N), 38.32 (1C, JC,P = 5.4 Hz, C-3), 21.16
3
(1C, JC,P = 2.7 Hz, C-1), 19.85, 19.75, 19.68, 19.57,
2-propanol/water) to give 11 (15 mg, 92%, 0.060 mmol)
19.56 (5C, CH3, Ac), 8.26 (CH3, Et3N); 31P NMR
(MeOD): d 0.9; TOF-ES-MS: m/z = 543.118 [M+H]+.
Calcd 543.147 [M+H]+.
20
as a colourless syrup. ½aŠ ¼ À11 (c 0.8, H2O); 1H
D
NMR (D2O): d 3.96 (m, 1H, H-2), 3.96 (m, 1H, H-9),
3.82 (br d, 1H, J5,6 = 3.3 Hz, H-5), 3.74 (dd, 1H,
3
3J9,10a = 3.6 Hz, J10a,10b = 12.0Hz, H-10a), 3.65 (dd,
2
1H,
3J9,10b = 7.0Hz,
H-10b),
3.64
(t,
1H,
4.1.8. Triethylammonium 5,6,7,9,10-penta-O-acetyl-4,8-
anhydro-1,3-dideoxy-D-ribo-L-gluco-decitol 2-phosphate
15. A solution of 10 (30 mg, 0.041 mmol) in dry
MeOH (9 mL) was hydrogenated in the presence of
10% Pd/C (9 mg) for 10 h at atmospheric pressure. After
the completion of the reaction, the catalyst was removed
by filtration through a pad of Celite and washed with
MeOH. The combined filtrates were neutralized by addi-
tion of Et3N (7 lL) and concentrated. The residue was
lyophilized from water to give the monotriethylammo-
nium salt of 15 (25 mg, 95%, 0.039 mmol) as an amor-
phous solid. Rf 0.75 (5:10:2:2, CHCl3/MeOH/25% aq
3J7,8 = 3J7,6 = 9.5 Hz, H-7), 3.62 (m, 1H, H-6), 3.59
(ddd, 1H, H-4), 3.33 (dd, 1H, J8,9 = 3.6 Hz, H-8), 1.83
3
3
(ddd, 1H, J3a,4 = 5.3 Hz, J3a,2 = 5.3 Hz, J3a,3b = 14.2
3
2
3
Hz, H-3a), 1.62 (ddd, 1H, J3b,4 = 7.7 Hz, J3b,2
3
=
3
7.7 Hz, H-3b), 1.17 (d, 3H, J1,2 = 6.2 Hz, H-1);
13C NMR (D2O): d 80.95 (C-8), 77.18 (C-6), 75.27 (C-
4), 72.96 (C-9), 71.44 (C-5), 68.89 (C-7), 66.31 (C-2),
62.69 (C-10), 39.58 (C-3) and 22.75 (C-1). TOF-ES-
MS: m/z = 253.103 [M+H]+. Calcd 253.128 [M+H]+.
4.1.6.
4,8-Anhydro-1,3-dideoxy-D-ribo-L-gluco-decitol
20
D
1
12. A solution of 8 (25 mg, 0.065 mmol) in 3:2:1
MeOH–water–Et3N (2 mL) was stirred at room temper-
ature for 3 h. The reaction mixture was evaporated and
purified by a flash chromatography (4:2:0.25 EtOAc/2-
NH4OH/H2O); ½aŠ ¼ À11:0 (c 0.2, MeOH); H NMR
3
(MeOD): d 5.26 (d, 1H, J5,6 = 3.0Hz, H-5), 5.19 (dd,
1H, J7,8 = 9.8 Hz, H-7), 5.15 (m, 1H, H-9), 5.12 (dd,
3
3
1H, J6,7 = 9.8 Hz, H-6), 4.42 (dd, 1H, J10a,9 = 3.4 Hz,
3
propanol/water) to give 12 (16 mg, 97%, 0.063 mmol)
2J10a,10b = 12.0Hz, H-10a), 4.36 (m, 1H, H-2), 4.21
(dd, 1H, J10b,9 = 8.2 Hz, H-10b), 4.05 (br d, 1H, H-4),
20
D
3
as a colourless syrup. ½aŠ ¼ À35 (c 0.6, H2O); 1H
3
NMR (D2O): d 3.96 (m, 1H, H-2), 3.96 (m, 1H, H-9),
3.75 (br d, 1H, J5,6 = 4.9 Hz, H-5), 3.74 (dd, 1H,
3.85 (dd, 1H, J8,9 = 3.0Hz, H-8), 3.16 (q, ꢀ6H, CH2,
3
Et3N), 2.15, 2.07, 2.06, 2.02, 1.94 (5s, 15H, CH3, Ac)
1.68 (m, 1H, H-3a), 1.52 (m, H-3b), 1.33 (d, 3H,
3J1,2 = 7.2 Hz, CH3), 1.27 (t, ꢀ9H, CH3, Et3N); 13C
NMR (MeOD): d 171.55, 171.29, 171.10, 170.72,
170.58 (5C, CO, Ac), 76.82 (C-8), 73.75 (C-4), 73.13
(C-6), 71.39, 71.08 (C-5, C-9), 68.96 (1C,
3J2,P = 5.5 Hz, C-2), 67.33 (C-7), 62.30(C-1)0, 46.68
3J9,10a = 3.9 Hz, J10a,10b = 12.0Hz, H-10a), 3.65 (dd,
2
1H,
3J9,10b = 7.0Hz,
H-10b),
3.64
(t,
1H,
3J7,6 = 10.0 Hz, H-7), 3.63 (m, 1H, H-6), 3.59 (ddd,
1H, H-4), 3.32 (dd, 1H, J8,9 = 3.9 Hz, J8,7 = 9.0Hz,
3
3
3
H-8), 1.79 (ddd, 1H, J3a,4 = 3.5 Hz, J3a,2 = 10.0,
3
2J3a,3b = 14.0Hz, H-3a), 1.49 (ddd, 1H, J3b,4 = 3.2 Hz,
3
3J3b,2 = 9.2 Hz, H-3b), 1.17 (d, 3H, J1,2 = 6.3 Hz, H-
(CH2, Et3N), 40.08 (1C, JC,P = 6.5 Hz, C-3), 22.06
3
3
3
1); 13C NMR (D2O): d 80.51 (C-8), 75.84 (C-6), 75.31
(C-4), 73.21 (C-9), 72.26 (C-5), 69.18 (C-7), 65.19 (C-
2), 62.73 (C-10), 40.33 (C-3) and 23.41 (C-1). TOF-ES-
MS: m/z = 253.103 [M+H]+.
(1C, JC,P = 2.0Hz, C-1), 19.97, 19.77, 19.69, 19.57,
19.56 (5C, CH3, Ac), 8.29 (CH3, Et3N); 31P
NMR (MeOD): d 0.3; TOF-ES-MS: m/z = 543.127
[M+H]+.

A. Graziani et al. / Tetrahedron: Asymmetry 16 (2005) 167–175
173
4.1.9. Triethylammonium 4,8-anhydro-1,3-dideoxy-D-
ribo-L-manno-decitol 2-phosphate 14. A solution of 13
(25 mg, 0.039 mmol) in 7:3:1 MeOH–water–Et3N
(2 mL) was stirred at room temperature for 3 h at
pH 12. The reaction mixture was diluted with water
and purified on an anion-exchange column. The eluate
was concentrated and lyophilized to give 14 (16 mg,
and a catalytic amount of 4-N,N-dimethylaminopyr-
idine was added. The solution was stirred for 15 h at
room temperature, MeOH (2 mL) was added, and the
mixture was coevaporated three times with toluene.
The residue was purified on a column of silica gel (dieth-
ylether), which afforded 21 as the major compound.
20
D
Yield: 140mg (77%), colourless syrup; ½aŠ ¼ À52 (c
95%, 0.037 mmol) as a white fluffy solid. Rf 0.15
(5:10:2:2, CHCl3/MeOH/25% aq NH4OH/H2O); ½aŠ
0.7, CHCl3); 1H NMR (CDCl3): d 5.32 (dd, 1H,
20
D
3
¼
3J5,4 = 0.9 Hz, H-5), 5.30–5.21 (m, 1H, J7,8 = 9.9 Hz,
1
À5:0 (c 1.4, H2O); H NMR (D2O): d 4.27 (m, 1H, H-
3J7,6 = 10.1 Hz, H-7), 5.30–5.21 (m, 1H, H-9), 5.08 (dd,
1H, J6,5 = 3.4 Hz, H-6), 4.27 (dd, 1H, J10a,9 = 5.3 Hz,
H-10a), 4.17 (ddd, 1H, H-4), 4.08 (dd, 1H,
3
3
2), 3.95 (m, 1H, H-9), 3.92 (br s, 1H, H-5), 3.75 (dd,
1H, J10a,9 = 5.0Hz, J10a,10b = 12.0Hz, H-10a), 3.68
3
2
3
(m, 1H, H-6), 3.66 (dd, 1H, J10b,9 = 3.6 Hz, H-10b),
3.63 (m, 1H, H-7), 3.63 (m, 1H, H-4), 3.36 (dd, 1H,
2
3J10b,9 = 7.8 Hz, J10b,10a = 11.5 Hz, H-10b), 3.72 (dd,
1H, J8,9 = 2.5 Hz, H-8), 2.82 (dd, 1H, J3a,4 = 8.2 Hz,
3
3
3J8,9 = 4.0Hz, J8,7 = 9.5 Hz, H-8), 3.17 (q, ꢀ12H,
H-3a), 2.44 (dd, 1H, J3b,4 = 4.3 Hz, J3a,3b = 17.4 Hz,
H-3b), 2.21 (s, 3H, CH3), 2.15, 2.11, 2.05, 1.99, 1.96
(5s, 15H, CH3, Ac); 13C NMR (CDCl3): d 204.03 (C-
2), 170.68, 170.63, 170.49, 170.11, 169.78 (5C, CO,
Ac), 76.90(C-8), 73.72 (C-4, JC-4,H-4 = 142 Hz), 72.51
(C-6), 70.18 (C-5), 67.21 (C-9), 64.87 (C-7), 62.27 (C-
10), 44.04 (C-3), 30.74 (C-1), 20.93, 20.91, 20.83, 20.78,
20.71 (5C, CH3, Ac); Anal. Calcd for C20H28O12: C,
52.17; H, 6.13. Found: C, 52.19; H, 6.05.
3
3
2
CH2, Et3N), 1.86 (m, 1H, H-3a), 1.72 (m, 1H, H-3b),
1.25 (t, ꢀ18H, CH3, Et3N), 1.24 (s, 3H, CH3); 13C
NMR (D2O): d 80.80 (C-8), 76.34 (C-6), 75.22 (C-4),
3
73.11 (C-9), 71.31 (C-5), 69.26 (1C, J2,P = 4.9 Hz, C-
2), 68.96 (C-7), 62.70(C-10), 47.49 (CH 2, Et3N), 38.83
(1C, JC,P = 4.8 Hz, C-3), 22.01 (C-1, JC-1,P = 2.5 Hz),
3
9.08 (CH3, Et3N); 31P NMR (D2O): d 2.53. TOF-ES-
MS: m/z = 333.100 [M+H]+. Calcd. 333.095 [M+H]+.
4.1.10. Triethylammonium 4,8-anhydro-1,3-dideoxy-D-
ribo-L-gluco-decitol 2-phosphate 16. A solution of 15
(34 mg, 0.053 mmol) in 7:3:1 MeOH–water–Et3N
(2 mL) was stirred at room temperature for 3 h at
pH 12. The reaction mixture was diluted with water
and purified on an anion-exchange column. The eluate
was concentrated and lyophilized to give 16 (22 mg,
95%, 0.050 mmol) as a white fluffy solid. Rf 0.15
(5:10:2:2, CHCl3/MeOH/25% aq NH4OH/H2O);
Acetylation of the mixture: An aliquot of the lyophilized
mixture of 18 and 20 (15 mg) was dissolved in pyridine
(3 mL). Acetic anhydride (1 mL) and a catalytic amount
of 4-N,N-dimethylaminopyridine were added and the
solution was stirred for 15 h at room temperature. After
addition of MeOH (0.1 mL), the solution was coevapo-
rated with toluene and the residue was purified by silica
gel chromatography to give 21 as the higher running
component (12 mg) followed by 19 (13 mg); colourless
20
20
1
1
½aŠ ¼ À15 (c 1.7, H2O); H NMR (D2O): d 4.32 (m,
syrup; ½aŠ ¼ À26 (c 0.5, MeOH); H NMR (CDCl3):
D
1H, H-2), 3.94 (m, 1H, H-9), 3.83 (d, 1H,
D
3
d 5.34 (ddd, 1H, J8,9 = 2.3 Hz, H-9), 5.29–5.14
(m, 3H, H-5, H-6, H-7), 4.55 (ddd, 1H, J5,4 = 2.9 Hz,
3J4,5 = < 1.0Hz, H-5), 3.78 (dd, 1H, 3J10a,9 = 6.0,
3
2J10a,10b = 12.0Hz,
H-10a),
3.75
(dd,
1H,
3
H-4), 4.25 (dd, 1H, J10a,9 = 4.9 Hz, H-10a), 4.07 (dd,
3J10b,9 = 3.4 Hz, H-10b) 3.73 (m, 1H, H-6), 3.68 (m,
1H, J10b,9 = 7.0Hz, J10b,10a = 11.7 Hz, H-10b), 3.89
(dd, 1H, 3J8,7 = 7.7 Hz, H-8), 2.87 (dd, 1H,
3
2
3
1H, H-7), 3.65 (m, 1H, H-4), 3.41 (dd, 1H, J8,9 = 4.0,
3J8,7 = 9.0Hz, H-8), 3.19 (q, ꢀ12H, CH2, Et3N), 1.72
(m, 2H, H-3), 1.26 (s, 3H, CH3), 1.27 (t, ꢀ18H, CH3,
Et3N); 13C NMR (D2O): d 79.61 (C-8), 75.92 (C-6),
75.06 (C-4), 73.20 (C-9), 71.81 (C-5), 69.47 (C-7),
3J3a,4 = 9.5 Hz, H-3a), 2.68 (dd, 1H, J3b,4 = 5.2 Hz,
3
2J3a,3b = 15.0Hz, H-3b), 2.20 (s, 3H, CH 3), 2.15, 2.13,
2.05, 2.03, 2.02 (5s, 15H, CH3, Ac); 13C NMR (CDCl3):
d 203.41 (C-2), 170.56, 170.34, 170.07, 169.96, 169.42
3
69.24 (1C, J2,P = 4.8 Hz, C-2), 62.24 (C-10), 47.09
(5C, CO, Ac), 71.48 (C-8), 71.25 (C-4, JC-4,H-4 =
(CH2, Et3N), 39.70(1C, 3JC,P = 5.8 Hz, C-3), 22.63
(C-1, JC-1,P = 2.4 Hz), 8.26 (CH3, Et3N); 31P NMR
(D2O): d = 2.5; TOF-ES-MS: m/z = 333.100 [M+H]+.
Calcd 333.095 [M+H]+.
151 Hz), 69.85 (C-6), 68.83 (C-5), 66.92 (C-9), 65.50
(C-7), 62.20(C-1)0, 43.14 (C-3), 29.80(C-1), 2.091,
20.75 (d.i.), 20.69, 20.63 (5C, CH3, Ac).
4.1.12. 4,8-Anhydro-1,3-dideoxy-L-threo-D-galacto-dec-
2-ulose 20. A solution of 21 (450mg, 0.98 mmol) in
dry MeOH (10mL) was stirred with 0.1 M NaOMe
(0.5 mL) for 15 h at room temperature. The solution
was made neutral by adding Dowex 50resin (H + form),
4.1.11. 5,6,7,9,10-Penta-O-acetyl-4,8-anhydro-1,3-dide-
oxy-L-threo-D-galacto-dec-2-ulose 21. A solution of 17
(300 mg, 1.43 mmol), NaHCO3 (180mg, 2.5 mmol)
and pentane-2,4-dione (180 lL, 1.72 mmol) in water
(10mL) was stirred at 90 ꢁC for 16 h. The solution
was diluted with water and neutralized with Dowex 50
resin (H+ form). The resin was filtered off, and the fil-
trate was lyophilized. Yield: 261 mg (73%). An aliquot
of the mixture (100 mg) was dissolved in dry MeOH
(3 mL) and stirred with 1.0M methanolic NaOMe
(2 mL) for 15 h at room temperature. The solution
filtered and concentrated, which furnished 20 as amor-
20
D
4.00 (ddd, 1H,
phous solid. Yield: 240mg (98%); ½aŠ ¼ À15 (c 0.5,
MeOH); 1H NMR (D2O):
d
3
3J5,4 = 1.0Hz, H-4), 3.94 (ddd, 1H, J9,8 = 1.5 Hz,
3J9,10a = 6.2, J9,10b = 7.7 Hz, H-9), 3.83 (dd, 1H,
3
3J5,6 = 3.7 Hz, H-5), 3.77 (t, 1H, J7,6 = 3J7,8 = 9.6 Hz,
H-7), 3.66 (dd, 1H, H-6), 3.64–3.59 (m, 2H, H-10a, H-
3
+
was made neutral by addition of Dowex 50resin (H
form), filtered and concentrated. The residue was dis-
solved in dry pyridine (4 mL), acetic anhydride (2 mL)
10b), 3.29 (dd, 1H, H-8), 2.94 (dd, 1H, 2J3a,3b = 16.6 Hz,
3
3J3a,4 = 9.4 Hz, H-3a), 2.71 (dd, 1H, J3b,4 = 3.8 Hz, H-
3b) and 2.24 (s, 3H, H-1); 13C NMR (D2O): d 214.08

174
A. Graziani et al. / Tetrahedron: Asymmetry 16 (2005) 167–175
3
1H, H-2), 3.95 (ddd, 1H, J9,8 = 1.8 Hz, H-9), 3.82 (dd,
(C-2), 79.31 (C-8), 75.12 (C-4), 74.96 (C-6), 71.65 (C-5),
69.56 (C-9), 66.91 (C-7), 63.79 (C-10), 45.18 (C-3) and
30.56 (C-1); Anal. Calcd for C10H18O7. 0.5 H2O: C,
46.33; H, 7.39. Found: C, 45.88; H, 7.85.
3
3
1H, J4,5 = 1.0Hz, J5,6 = 3.5 Hz, H-5), 3.78 (t, 1H,
3J7,8 = 3J7,6 = 9.7 Hz, H-7), 3.71–3.63 (m, 3H, H-4, H-
10a, H-10b), 3.63 (dd, 1H, H-6), 3.27 (dd, 1H, H-8),
1.89 (ddd, 1H, 2J3a,3b = 14.3 Hz, 3J3a,4 = 8.9 Hz,
3
4.1.13. 5,6,7,9,10-Penta-O-acetyl-4,8-anhydro-1,3-dideoxy-
L-lyxo-L-manno-decitol 22 and 5,6,7,9,10-penta-O-acetyl-
3J3a,2 = 6.9 Hz, H-3a), 1.61 (ddd, J3b,4 = 4.5 Hz,
3
3J3b,2 = 5.9 Hz, H-3b), 1.19 (d, 3H, J1,2 = 6.3 Hz, H-
4,8-anhydro-1,3-dideoxy-L-lyxo-L-gluco-decitol 24.
A
1); 13C NMR (D2O): d 79.36 (C-8), 76.83 (C-4), 75.30
(C-6), 71.98 (C-59), 69.66 (C-9), 67.17 (C-7), 66.42 (C-
2), 63.93 (C-10), 39.61 (C-3) and 22.46 (C-1). Anal.
Calcd for C10H20O7ÆH2O: C, 44.44; H, 8.20. Found: C,
44.69; H, 7.12.
solution of 21 (80mg, 0.17 mmol) in dry MeOH
(10mL) was cooled to À10 ꢁC. NaBH4 (90mg) and
AcOH (130 lL) were added. The solution was stirred
for 30min, then concentrated. The residue was dissolved
in EtOAc (100 mL). The organic phase was washed with
water, dried (Na2SO4) and concentrated. The remainder
was purified on a column of silica gel (1:1 CH2Cl2/Et2O),
which afforded 22 as the first fraction. Yield: 40mg
4.1.15. 4,8-Anhydro-1,3-dideoxy-L-lyxo-L-gluco-decitol
25. A solution of 24 (15 mg) was treated as described
above. Yield of 25: 8.0mg (97%) as colourless solid.
20
D
20
1
1
(50%); ½aŠ ¼ À50( c 0.9, CHCl3); H NMR (CDCl3):
½aŠ ¼ À46 (c 0.8, MeOH); H NMR (D2O): d 3.99–
D
3.87
3
d 5.36 (dd, 1H, J5,4 = 1.0Hz, H-5), 5.28 (t, 1H,
(m,
2H,
H-2,
H-9);
3.73
(t,
1H,
3J7,6 = 3J7,8 = 10.0 Hz, H-7), 5.24 (ddd, 1H, J9,8
=
2.5 Hz, H-9), 5.06 (dd, 1H, J5,6 = 3.5 Hz, H-6), 4.38
3J7,8 = 3J7,6 = 9.7 Hz, H-7), 3.77–3.63 (m, 5H, H-4,
H-5, H-6, H-10a, H-10b), 3.23 (dd, 1H, J8,9 = 1.6 Hz,
3
3
3
3
(dd, 1H, J9,10a = 5.3 Hz, J10a,10b = 11.5 Hz, H-10a),
2
2
3
H-8), 1.80(ddd, 1H, J3a,3b = 14.6 Hz, J3a,4 = 10.3 Hz,
3J3a,2 = 3.5 Hz, 3J3b,4
H-3a), 1.47 (ddd,
3
4.11 (dd, 1H, J9,10b = 7.3 Hz, H-10b), 3.93 (m, 1H, H-
=
2.7 Hz, 3J3b,2 = 9.3 Hz, H-3b), 1.16 (d, 3H,
3J1,2 = 6.4 Hz, H-1); 13C NMR (D2O): d 78.96 (C-8),
75.46 (C-4), 75.40(C-6), 72.60(C-5), 69.72 (C-9),
67.17 (C-7), 65.35 (C-2), 63.65 (C-10), 40.36 (C-3) and
23.45 (C-1). Anal. Calcd for C10H20O7Æ0.4H2O: C,
46.61; H, 8.04. Found: C, 46.16; H, 7.67.
3
2), 3.85 (ddd, 1H, J3a,4 = 8.3 Hz, H-4), 3.68 (dd, 1H,
H-8), 2.20, 2.12, 2.06, 2.01, 1.97 (5s, 15H, Ac), 1.85
(dt, 1H, J3a,3b = 14.4 Hz, H-3a), 1.55 (ddd, 1H,
2
3
3J3b,2 = 4.0Hz, J3b,4 = 5.1 Hz, H-3b), 1.19 (d, 3H,
3J1,2 = 6.2 Hz, H-1); 13C NMR (CDCl3): d 170.58
(d.i.), 170.37, 170.14, 169.55 (5C, CO, Ac), 77.07 (C-
8), 76.87 (C-4), 72.51 (C-6), 69.75 (C-5), 67.05 (C-9),
65.57 (C-2), 64.80(C-7), 62.17 (C-1)0, 39.11 (C-3),
23.59 (C-1), 20.76 (d.i.), 20.71, 20.64, 20.59 (5C, CH3,
Ac). Anal. Calcd for C20H30O12: C, 51.94; H, 6.54.
Found: C, 51.97; H, 6.53.
Acknowledgements
The authors thank Daniel Kolarich for recording MS
spectra and Maria Hobel for technical assistance. Finan-
cial support of this work by a grant from FWF (P14978)
is gratefully acknowledged.
Further elution of the column gave 24 as a colourless
20
D
syrup; yield: 35 mg (44%); ½aŠ ¼ À60( c 0.7, CHCl3);
3
1H NMR (CDCl3): d 5.31 (dd, 1H, J5,4 = 1.0Hz, H-
5), 5.28 (t, 1H, J7,6 = 3J7,8 = 10.0 Hz, H-7), 5.21 (ddd,
1H, J9,8 = 2.3 Hz, H-9), 5.07 (dd, 1H, J5,6 = 3.5 Hz,
3
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3
3
3
H-6), 4.57 (dd, 1H, J9,10a = 6.5 Hz, J10a,10b = 11.3 Hz,
2
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H-10a), 4.03 (dd, 1H, J9,10b = 8.7 Hz, H-10b), 4.03
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3J3b,4 = 2.7 Hz, J3b,2 = 10.3 Hz, H-3b), 1.20 (d, 3H,
3J1,2 = 6.2 Hz, H-1); 13C NMR (CDCl3): d 170.81,
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C, 51.78; H, 6.24.
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MeOH (2 mL) was stirred with 0.1 M methanolic
NaOMe (0.1 mL) for 3 h at room temperature. The
solution was diluted with MeOH (10mL), neutralized
+
by addition of Dowex 50resin (H form), filtered and
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D
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