Toward the assembly of heparin and heparan sulfate oligosaccharide libraries: efficient synthesis of uronic acid and disaccharide building blocks

Article abstract of DOI:10.1016/j.tet.2010.03.077

The monosaccharide moieties found in heparin (HP) and heparan sulfate (HS), glucosamine and two kinds of uronic acids, glucuronic and iduronic acids, were efficiently synthesized by use of glucosamine hydrochloride and glucurono-6,3-lactone as starting compounds. In the synthesis of the disaccharide building block, the key issues of preparation of uronic acids (glucuronic acid and iduronic acid moieties) were achieved in 12 steps and 15 steps, respectively, without cumbersome C-6 oxidation. The resulting monosaccharide moieties were utilized to the syntheses of HP/HS disaccharide building blocks possessing glucosamine-glucuronic acid (GlcN-GlcA) or iduronic acid (GlcN-IdoA) sequences. The disaccharide building blocks were also suitable for further modification such as glycosylation, selective deprotection, and sulfation.

Full text of DOI:10.1016/j.tet.2010.03.077

Tetrahedron 66 (2010) 3951–3962
Contents lists available at ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Toward the assembly of heparin and heparan sulfate oligosaccharide libraries:
efficient synthesis of uronic acid and disaccharide building blocks
,
a
a
b
a,c,
*
Akihiro Saito a, Masahiro Wakao a , Hiroshi Deguchi , Aya Mawatari , Michael Sobel , Yasuo Suda
*
a Department of Chemistry, Biotechnology, and Chemical Engineering, Graduate School of Science and Engineering, Kagoshima University, 1-21-40 Kohrimoto,
Kagoshima 890-0065, Japan
b Division of Vascular Surgery, VA Puget Sound Health Care System and the University of Washington, School of Medicine, Seattle, WA, USA
c SUDx-Biotec Corporation, 1-42-1, Shiroyama, Kagoshima 890-0013, Japan
a r t i c l e i n f o
a b s t r a c t
Article history:
The monosaccharide moieties found in heparin (HP) and heparan sulfate (HS), glucosamine and two
kinds of uronic acids, glucuronic and iduronic acids, were efficiently synthesized by use of glucosamine
hydrochloride and glucurono-6,3-lactone as starting compounds. In the synthesis of the disaccharide
building block, the key issues of preparation of uronic acids (glucuronic acid and iduronic acid moieties)
were achieved in 12 steps and 15 steps, respectively, without cumbersome C-6 oxidation. The resulting
monosaccharide moieties were utilized to the syntheses of HP/HS disaccharide building blocks pos-
sessing glucosamine–glucuronic acid (GlcN–GlcA) or iduronic acid (GlcN–IdoA) sequences. The
disaccharide building blocks were also suitable for further modification such as glycosylation, selective
deprotection, and sulfation.
Received 18 November 2009
Received in revised form 22 March 2010
Accepted 22 March 2010
Available online 27 March 2010
Keywords:
Synthesis
Uronic acid
Glucuronic acid
Iduronic acid
Glucosamine
Heparin
Ó 2010 Elsevier Ltd. All rights reserved.
Heparan sulfate
1. Introduction
target molecules. Many synthetic approaches to the synthesis of
HP/HS oligosaccharides have been so far performed.3–7
Heparin (HP) and heparan sulfate (HS) are highly sulfated
polysaccharides, and are the most complex carbohydrates among
the glycosaminoglycan (GAG) superfamily.1 HP/HS are basically
Recently, a synthetic strategy for the assembly of a HP/HS oli-
gosaccharide library has attracted much attention, because it offers
a
more comprehensive evaluation of HP/HS biological func-
composed of a repeating
a
or
b
(1,4)-linked disaccharide unit,
tions.4c,5,6a For this accomplishment, the efficient synthesis of
uronic acid moieties and disaccharide building blocks accessible to
HP/HS oligosaccharides with various sugar and sulfation patterns is
required. As neither idose nor iduronic acid derivatives are com-
mercially available, their syntheses are especially important. Cur-
rently, iduronic acid moieties are synthesized from glucose or
glucuronic acid as a starting material, involving C-5 epimerization
and/or C-6 oxidation.7 But C-5 epimerization sometimes needs to
be carried out under harsh conditions, such as, strong basic con-
ditions, and the range of usable protective groups is restricted. C-6
Oxidation is also sometimes problematic in yield and repeatability.
So far, many intermediates suitable for the structure of HP/HS have
been developed as HP/HS building blocks.3–7
which is derived from uronic acid, either glucuronic acid or idur-
onic acid, and N-acetyl-glucosamine residues. The structure is very
heterogeneous and contains various substitution patterns derived
from the multiple and random enzymatic modifications in their
biosynthesis. The diverse micro- or domain structure, which is
derived from the enzymatic modification, is considered to regulate
the activity of many important biological proteins, such as growth
factors, cytokines, viral proteins, and coagulation factors, through
their binding interactions in many biological processes.1,2 The
elucidation of the structure–function relations of HP/HS micro-
structures at the molecular level is, however, very difficult due to
their naturally occurring structural diversity. Therefore, structur-
ally defined HP/HS sequences (oligosaccharides) are essential for
the precise understanding of the interactions of HP/HS with their
Previously, we reported the synthesis and analysis of a variety of
HP/HS oligosaccharides for investigating their binding properties,6
in which we clarified that an appropriate HP/HS disaccharide
structure was needed for the specific binding between sugar
component and protein. Although further investigation of HP/HS
binding properties was needed, our previous synthetic route was
* Corresponding authors. Tel./fax: þ81 99 285 7843; e-mail addresses: wakao@
eng.kagoshima-u.ac.jp (M. Wakao), ysuda@eng.kagoshima-u.ac.jp (Y. Suda).
0040-4020/$ – see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2010.03.077

3952
A. Saito et al. / Tetrahedron 66 (2010) 3951–3962
not suitable for the generation of a sufficiently diverse sugar and
sulfation pattern. In this study, we synthesized novel disaccharide
building blocks for the systematic analysis of HP/HS binding
properties.
introduced for the further elongation of the sugar chain. Two uronic
acid moieties are prepared from glucurono-6,3-lactone, which is
already oxidized at the C-6 position. The synthetic route is expected
to be simple because a cumbersome oxidation step can be omitted.
Conversion to ido-form is achieved by the inversion reaction at C-5
position on furanose form.
2. Results and discussion
Syntheses of uronic acid moieties were carried out as shown in
Scheme 1. Firstly, inexpensive glucurono-6,3-lactone 1 was trans-
formed to 1,2-isopropylidene 2 according to the method reported
previously.7m Obtained 2 was then converted to furanose 3 in 43%
overall yield in four steps through simple protection and depro-
tection processes of hydroxy groups. The removal of the iso-
propylidene group on furanose 3 by treatment with trifluoroacetic
acid (TFA) gave triol 4. Conversion to pyranose form by 1,2-selective
protection was then examined. First, 1,2-cyclic acetal protection to
obtain pyranose form was used.4h,7a Unfortunately, the resulting
uronic acid derivatives were a mixture of pyranose and furanose
forms under the conditions of acetal formation, suggesting a lower
Our synthetic strategy is shown in Figure 1. The two disaccharide
building blocks containing gluco- and ido-type are prepared from
two common monosaccharides, D-glucosamine and D-glucurono-
6,3-lactone. They contain a diverse set of protective groups for
generating various sulfation patterns. O-Sulfation is achieved by
selective removal of benzoyl (Bz), 4-methoxybenzyl (MPM), and/or
tert-butyldiphenylsilyl (TBDPS) groups. Conversion of the azido
group to amine, N-sulfate, and/or N-acetate is achieved by reduction
of azido group followed by N-sulfation and/or N-acetylation. A glu-
cosamine moiety containing different protective groups is easily
prepared from glucosamine. A levulinyl (Lev) group at 4-position is
gluco- or ido-form
gluco- or ido-form
-
OR2
CO2
CO2Me
O
OTBDPS
O
OR1
O
O
OR2
OH
OTBDMS
OBn
OMPM
R3O
LevO
O
O
2 disaccharide biulding blocks
OBz
NHR2
OR2
N3
48 disaccharide units
OTBDPS
CO2Me
O
HO
OH
O
OTBDMS
or
O
O
O
CO2Me
OBn
O
t
SPh Bu
OBn
OMPM
OH
O
OH
OH
LevO
LevO
LevO
OTBDMS
OBz
HO
OBz
2 uronic acid moieties
Figure 1. Synthetic route of heparin/heparan sulfate disaccharide structures.
N3
NH2
glucosamine
OH
glucosamine moiety
glucurono-6,3-lactone
CO2Me
O
O
HO
HO
CO2Me
O
HO
O
O
O
OBn
g
f
a
h
b-e
O
O
OH
OH
OBn
O
O
HO
O
OH
O
OH
2
3
4
glucurono-6,3-lactone 1
CO2Me
O
CO2Me
O
CO2Me
O
CO2Me
OTBDMS
OTBDMS
O
i-k
l
i
i
O
O
OBn
OBn
Pr
Pr
OBn
OBn
Si
Si
i
HO
LevO
i
Pr
Pr
LevO
HO
O
O
O
O
i
Pr
Si
Si
OBz
OBz
5
6
i
i
i
7
8
Pr
Pr
Pr
CO2Me
OLev
CO2Me
OH
O
i
CO2Me
OBn
O
CO2Me
OBn
Pr
O
O
r
m, n
o
p
q
OH
OBn
OBn
O
Si
3
i
HO
v
Pr
HO
O
O
O
O
Si
OH
O
O
9
10
11
12
i
i
Pr
Pr
O
O
O
O
i
CO2Me
OBn
Pr
CO2Me
OBn
CO2Me
CO2Me
s
t, u
OH
OBn
OBn
O
Si
i
LevO
Pr
LevO
LevO
OTBDMS
OBz
HO
OTBDMS
OBz
O
O
OH
Si
13
i
14
15
16
i
Pr
Pr
Scheme 1. Syntheses of uronic acid moieties: (a) H2SO4 in acetone, 84%; (b) TBDMSCl, imidazole in CH2Cl2; (c) 1.0 M MeONa in MeOH (d) BnOC(]NH)CCl3, TBDMSOTf, MS4Ap in
CH2Cl2, 0 ꢀC; (e) TBAF, AcOH in THF, 43% (four steps); (f) TFA/H2O (9:1) (83%); (g) TIPDSCl2, imidazole in DMF, 85%; (h) LevOH, EDC$HCl, DMAP in CH2Cl2, 84%; (i) TBAF, AcOH in THF;
(j) TBDMSCl, imidazole, MS4Ap in CH2Cl2; (k) BzCl in pyridine, 78% (3 steps); (l) H2NNH2$H2O in pyridine/AcOH (3:2), 83%; (m) Tf2O, pyridine in CH2Cl2; (n) LevONa in DMF;
(o) H2NNH2$H2O in pyridine/AcOH (3:2), 56% (three steps); (p) TFA/H2O (9:1), 95%; (q) TIPDSCl2, imidazole in CH3CN, 78%; (r) LevOH, EDC$HCl, DMAP, TEA in DMF, 68%; (s) TBAF,
AcOH in THF, 90%; (t) TBDMSCl, imidazole, MS4Ap in CH2Cl2; (u) BzCl, DMAP in pyridine, 65% (two steps); (v) H2NNH2$H2O in pyridine/AcOH (3/2), 89%.

A. Saito et al. / Tetrahedron 66 (2010) 3951–3962
3953
yield of the desired pyranose form under the thermodynamic
control. Thus, 1,1,3,3-tetraisopropyldisiloxanylidene (TIPDS) as
a 1,2-selective protection group was chosen to yield the kinetically
controlled product. 1,2-Selective cyclic reaction with 1,3-dichloro-
1,1,3,3-tetraisopropyldisiloxane (TIPDSCl2) was performed under
the standard conditions8 using imidazole as a base in DMF to afford
pyranose form 5 in 85% yield with high pyranose-selectivity9
gave thioglycoside donor 23. Imidate donor 24 was also prepared in
the usual manner.
Two kinds of disaccharide building blocks were then synthesized
from the prepared monosaccharide moieties (Scheme 3). Glycosyl-
ationof thethioglycosidedonor23andglucuronate 8 wascarried out
by use of N-iodosuccinimide (NIS) in the presence of TBDMSOTf11 to
give disaccharide 25 only in 31% yield but with high a-selectivity.
(
a
/
b
¼5:3). Levulinylation of pyranose 5 gave 4-O-Lev 6, which
Thioglycoside 23 was ineffective on the glycosylation with iduronate
16. In contrast, glycosyl imidate 24 was found to be an efficient donor
in glycosylation both with glucuronate 8 and iduronate 16. These
reactions proceeded smoothly to produce disaccharide 25 and 26 in
was subsequently treated with tetra-n-butylammonium fluoride
(TBAF). The resultant was subjected to silylation with a TBDMS
group at the 1-position, benzoylation at the 2-position, and
delevulinylation to afford the glucuronic acid moiety
8
as
83% and 77% yields with high a-selectivity, respectively.
a glycosyl acceptor. Meanwhile, ido-furanose 10 was prepared
by a general SN2 reaction of the triflate of furanose 3 with
LevONa. After removal of the Lev group, the iduronic acid
moiety 10 was treated with TFA to afford triol 11. The reaction
of triol 11 with TIDPSCl2 and imidazole efficiently proceeded
when CH3CN was used as a solvent at ꢁ45 ꢀC, providing the
Next, we examined whether the disaccharide building blocks
could apply to further modifications like sugar-chain elongation,
selective deprotection, sulfation, and final deprotection, or not. One
of our goals is the assembly of an HP/HS disaccharide partial
structure library, in order to determine the structure–function re-
lations of their interactions with HP/HS binding molecules using
Sugar Chips. In our Sugar Chips system, a glucose moiety spacer is
often used at the reducing terminal. To prepare the oligosaccha-
rides for use in this system, we carried out syntheses of
trisaccharides containing GlcN–UroA–Glc (Scheme 4) and GlcN–
IdoA–Glc sequence (Scheme 5). The disaccharide building block 25
was first converted to glycosyl donor 28 via selective desilylation at
1-position followed by formation of imidate. Glycosylation of
spacer 29 with obtained 28 proceeded smoothly to give
trisaccharide 30 in satisfactory yield.
pyranose form 12 in 78% with
b-selectivity. After levulinylation
of 12 with LevOH, DCC, and TEA, iduronate 16 was then syn-
thesized as a similar transformation to the synthesis of the
glucuronic acid moiety 8.
Synthesis of the glucosamine donor 23 and 24 was carried out as
shown in Scheme 2. Azido glucose 18, which was prepared
according to the method reported previously,10 was converted to
thioglycoside 19. After removal of the acetyl group of thioglycoside
19, hydroxyl groups at 4- and 6-positions were selectively pro-
tected with isopropylidene group. The remaining hydroxyl group
was then protected with MPM group. The resultant was treated
with AcOH to produce diol 21. Selectively silylation of diol 21 at 6-
position with TBDPS group followed by levulinylation at 4-position
Meanwhile, the disaccharide building block 26 was selectively
converted to 1-OH form 31 by treatment of HF$pyridine, although
there was no selectivity by treatment of TBAF. Trisaccharide 33 was
prepared in a manner similar to that of trisaccharide 30.
OH
O
OAc
O
OAc
O
O
O
O
ref. 10
a
b, c
t
t
OH
OAc
SPh Bu
SPh Bu
OH
OAc
OAc
OH
HO
AcO
AcO
NH2•HCl
N3
N3
N3
18
19
20
glucosamine hydrochloride 17
OH
O
OTBDPS
O
OTBDPS
O
f, g
h
d, e
t
t
SPh Bu
SPh Bu
X
OMPM
OMPM
OMPM
HO
LevO
LevO
N3
N3
N3
23, X = -SPh Bu
24, X = -OC(=NH)CCl3
21
22
t
i, j
Scheme 2. Synthesis of glucosamine moiety: (a) TBDMSOTf, MSAW300, HSPhtBu in CH2Cl2, 73%; (b) 1.0 M MeONa in MeOH; (c) 2-methoxypropene, CSA in acetone, 74% (two steps);
(d) MPMCl, NaH in DMF; (e) AcOH/CH2Cl2/H2O (8:1:1), 75% (two steps); (f) TBDPSCl, imidazole in DMF; (g) LevOH, EDC$HCl, DMAP in DMF, 89% (two steps); (h) NCS in acetone/H2O
(5:2), 73%; (i) CCl3CN, Cs2CO3 in CH2Cl2.
(A) NIS, TBDMSOTf
CO2Me
O
CO2Me
O
OTBDPS
O
MS4Ap in toluene
31%
OTBDMS
OTBDMS
23 (for A)
or
+
OBn
OMPM
OBn
24 (for B)
(B) TBDMSOTf
MS4Ap in toluene
83%
O
HO
LevO
OBz
OBz
N3
8
25
(A) NIS, TBDMSOTf
MS4Ap in CH2Cl2
41%
OTBDPS
O
O
O
23 (for A)
or
CO2Me
CO2Me
+
OBn
OMPM
OBn
24 (for B)
(B) TBDMSOTf
MS4Ap in CH2Cl2
77%
O
HO
OTBDMS
OBz
LevO
OTBDMS
OBz
N3
16
26
Scheme 3. Synthesis of disaccharide building blocks 25 and 26: conditions (A) and (B) were used for glycosylation with thioglycoside 23 and glycosyl imidate 24, respectively.

3954
A. Saito et al. / Tetrahedron 66 (2010) 3951–3962
CO2Me
O
CO2Me
O
OTBDPS
O
OTBDPS
O
CO2Me
O
OTBDPS
O
OTBDMS
NH
a
b
OH
OCCCl3
OMPM
OMPM
OMPM
OBn
OBn
OBn
O
O
O
LevO
LevO
LevO
OBz
OBz
OBz
N3
N3
N3
25
27
28
HO
OBn
O
O
CO2Me
OTBDPS
O
OBn
OBn
O
O
BnO
OBn
OBn
OMPM
OBn
29
O
LevO
BnO
c
OBn
OBz
N3
30
Scheme 4. Synthesis of trisaccharide 30: (a) TBAF, AcOH in THF, 78%; (b) CCl3CN, Cs2CO3 in CH2Cl2; (c) TMSOTf, MS4Ap in CH2Cl2, 68% (two steps).
OTBDPS
O
OTBDPS
O
OTBDPS
O
NH
O
CO2Me
OBn
O
CO2Me
OBn
O
CO2Me
OBn
a
b
OH
OCCCl3
OMPM
OMPM
OMPM
O
O
O
LevO
LevO
LevO
OTBDMS
OBz
OBz
OBz
N3
N3
N3
26
31
32
O
OTBDPS
OBn
O
O
CO2Me
OBn
O
c
OMPM
OBn
O
LevO
BnO
OBz
OBn
N3
33
Scheme 5. Synthesis of trisaccharide 33: (a) HF$pyridine in pyridine, 73%; (b) CCl3CN, Cs2CO3 in CH2Cl2; (c) 29, TMSOTf, MS4Ap in CH2Cl2, 62% (two steps).
Selective sulfation and final deprotection were examined on tri-
moieties. Syntheses of uronic acid moieties, which are key issues in
the synthesis of HP/HS oligosaccharide, were efficiently prepared
using inexpensive glucurono-6,3-lactone as a starting compound
avoiding annoying oxidation processes. Selective pyranose forma-
tion was achieved using TIDPS group as protecting group at 1,2-
position. Glucuronate 8 and iduronate 16 were synthesized in 14%
(12 steps) and 5% (15 steps) overall yield from glucurono-6,3-
lactone, respectively. In addition, we demonstrated the synthesis
of sulfated trisaccharide 38, which was achieved by selective
deprotection and sulfation. Although further work will be needed
to achieve such goals as sugar-chain elongation, sulfation at other
positions, and deprotection, is required, various HP/HS oligosac-
charides can be prepared by use of these designed disaccharide
building blocks with minimal derivatization.
saccharide 30. The Lev group of trisaccharide 30 was selectively
deprotected by hydrazine. The occurring hydroxyl group was masked
with a methyl group as in our previous study.6a After removal of the
TBDPS group in compound 34, the Bz group and methyl ester were
hydrolyzed with NaOH. The azide group was then reduced with PMe3
and the resulting amino group was N-sulfated. Finally, all benzylic
protectivegroupswereremovedbyhydrogenolysisusingcatalyticPd/
C to give the desired trisaccharide 38 (Scheme 6).
In conclusion, we have designed novel disaccharide building
blocks for HP/HS oligosaccharide precursors, which possess or-
thogonally cleavable protective groups and are capable of gener-
ating diverse sulfation patterns. Two disaccharide building blocks
were efficiently synthesized using appropriate monosaccharide
O
O
CO2Me
O
CO2Me
O
OTBDPS
O
OTBDPS
O
OBn
OBn
O
O
a, b
c
OMPM
OBn
OBn
OBn
OMPM
OBn
OBn
OBn
O
O
LevO
MeO
MeO
BnO
MeO
BnO
OBn
OBn
OBz
OBz
N3
N3
30
34
-
O
O
CO2Me
O
CO2
OH
O
OH
O
OBn
OBn
O
O
O
d
e, f
OMPM
OMPM
OBn
OBn
OBn
O
O
BnO
BnO
MeO
OBn
OBn
OBz
OH
N3
N3
35
CO2
36
-
-
O
O
CO2
OH
O
OH
O
OBn
O
O
O
O
g
OH
OMPM
OH
OH
OBn
OH
O
O
-
BnO
HO
MeO
-
OBn
OH
OH
OH
NHSO3
NHSO3
37
38
Scheme 6. Synthesis of sulfated trisaccharide containing HP/HS disaccharide partial structure: (a) H2NNH2$H2O in pyridine/AcOH (3/2), 89%; (b) MeI, LHMDS in DMF, 85%; (c)
HF$pyridine in pyridine, 95%; (d) 1 M NaOH aq in MeOH/THF (1:1); (e) 1 M PMe3, 0.1 M NaOH aq in THF/MeOH (1:1); (f) SO3$pyridine, pH 9.5 in H2O; (g) 10% Pd/C, H2 (7 kg/cm2) in
H2O/MeOH/AcOH (5:5:1), 11% (four steps).

A. Saito et al. / Tetrahedron 66 (2010) 3951–3962
3955
3. Experimental
3.1. General
(789 ml, 0.789 mol) was added to the mixture at the same tem-
perature. After being stirred for 3 h, the mixture was concentrated
in vacuo and diluted in AcOEt. The organic layer was washed with
brine (3ꢂ), dried over Na2SO4, filtered, and concentrated in vacuo.
Flash chromatography (silica gel: 450 g, hexane/AcOEt¼6:1/2:1)
afforded compound 3 as a brown oil. Yield 38.1 g (43%, four steps).
1H and 13C NMR spectra were measured with a JEOL JMM-
ECA600KS spectrometer. The chemical shifts in CDCl3 are given in
d
values from tetramethylsilane as an internal standard. For mea-
1H NMR (600 MHz, CDCl3)
d 7.38–7.31 (5H, m, aromatic), 6.04 (1H,
surement in D2O, the DHO signal (4.65 ppm) was used as a refer-
ence. Mass spectra were obtained on a micrOTOF IIÔ (Bruker
Daltonics). Silica gel column chromatography was carried out using
d, J1,2¼4.1 Hz, H-1), 4.68 and 4.56 (each 1H, d, Jgem¼11.0 Hz, PhCH2),
4.64 (1H, d, J2,1¼4.1 Hz, H-2), 4.59 (1H, dd, J5,4¼6.1 Hz, J5,OH¼8.9 Hz,
H-5), 4.42 (1H, dd, J4,3¼3.4 Hz, J4,5¼6.1 Hz, H-4), 4.16 (1H, d,
J3,4¼3.4 Hz, H-3), 3.76 (3H, s, COOCH3), 3.40 (1H, d, JOH,5¼8.9 Hz, 5-
OH), 1.50 (3H, s, CH3), 1.36 (3H, s, CH3); 13C NMR (150 MHz, CDCl3)
silica gel 60B (Fuji Silysia, 40–63 mm) at medium pressure (2–4 kg/
cm2). Precoated Kieselgel 60 F254 (Merck) was used for thin layer
chromatography (TLC). Sephadex G25 fine was used for gel filtra-
tion chromatography. All chemicals were commercial grade
(Nacalai, Wako, TCI, Kanto, and Aldrich). MS4A powder was acti-
vated by heating at 350 ꢀC in vacuo for 3 h before use.
d
173.0, 136.5, 128.5, 128.4, 128.2, 128.2, 128.0, 112.1, 105.3, 83.1, 82.1,
79.6, 72.5, 69.8, 52.6, 26.8, 26.3; HRMS (positive mode) found: m/z
361.1268 [MþNa]þ, calcd for C17H22O7Na: 361.1263.
3.4. Methyl 3-O-benzyl-D-glucopyranosyluronate (4)
3.2. 1,2-O-Isopropylidene-
a-D-glucurono-6,3-lactone (2)
Compound 3 (57.0 mg, 0.168 mmol) was dissolved in TFA/H2O
(9:1,1.0 ml) and stirred for 1.5 h at room temperature. After removal
of volatiles, the toluene was added and azeotropically evaporated
twice. Flash chromatography (silica gel: 2.5 g, toluene/acetone¼3:1)
D
-Glucurono-6,3-lactone 1 (40.0 g, 0.227 mol) was suspended in
acetone (835 ml). H2SO4 (12.1 ml, 0.227 mol) was then added at
room temperature. After being stirred for 38 h, the reaction mixture
was neutralized with NaHCO3. After removal of insoluble materials
by filtration, the filtrate was concentrated in vacuo. The residue was
dissolved in AcOEt, and the resulting mixture was then washed
with brine, dried over Na2SO4, filtered, and concentrated in vacuo.
Crystallization from AcOEt and hexane afforded isopropylidene 2 as
afforded compound 4 as a brown solid. Yield 41.7 mg (83%,
a
/b¼5:2).
1H NMR (600 MHz, CDCl3)
d for a-anomer 7.43–7.35 (5H, m, aro-
matic), 5.43 (1H, s, H-1), 4.86 and 4.75 (each 1H, d, Jgem¼11.5 Hz,
PhCH2), 4.49 (1H, d, J5,4¼7.5 Hz, H-5), 4.00 (1H, dd, J4,3¼6.8 Hz,
J4,5¼7.5 Hz, H-4), 3.89–3.73 (5H, m, H-2, H-3, COOCH3); 13C NMR
a white solid. Yield 41.2 g (84%). 1H NMR (600 MHz, CDCl3)
d
6.00
(150 MHz, CDCl3) d for a-anomer 170.7,137.9,128.5,127.9,127.9, 91.4,
(1H, d, J1,2¼3.4 Hz, H-1), 4.96 (1H, dd, J4,3¼2.7 Hz, J4,5¼4.8 Hz, H-4),
4.84–4.83 (2H, m, H-2, H-3), 4.51 (1H, d, J5,4¼4.8 Hz, H-5), 2.86 (1H,
s, 5-OH), 1.53 (3H, s, CH3), 1.36 (3H, s, CH3); 13C NMR (150 MHz,
78.7, 74.2, 72.4, 70.5, 70.3, 52.5; HRMS (positive mode) found: m/z
361.0960 [MþNa]þ, calcd for C17H22O7Na: 321.0950.
CDCl3)
d
174.7, 113.6, 106.6, 82.9, 81.2, 77.9, 70.6, 26.9, 26.5; HRMS
3.5. Methyl 3-O-benzyl-1,2-O-(1,1,3,3-
tetraisopropyldisiloxanylidene)-D-glucopyranosyluronate (5)
(positive mode) found: m/z 239.0536 [MþNa]þ, calcd for
C9H12O6Na: 239.0532.
To a suspension of compound 4 (136 mg, 0.455 mmol), TIPDSCl2
(218 l, 0.683 mmol), and MS4AP (500 mg) in anhydrous DMF
3.3. Methyl 3-O-benzyl-1,2-O-isopropylidene-
a-
D-
m
glucofuranosyluronate (3)
(4.5 ml) was added imidazole (124 mg, 1.82 mmol) at room tem-
perature under Ar. After being stirred for 19 h, the reaction was
quenched by the addition of MeOH. The resulting mixture was di-
luted with AcOEt. The organic layer was washed with water, and
brine, dried over Na2SO4, filtered, and concentrated in vacuo. Flash
chromatography (silica gel: 450 g, hexane/EtOAc¼8:1/4:1) affor-
To a solution of compound 2 (56.9 g, 0.263 mol) in CH2Cl2
(400 ml) were added imidazole (35.8 g, 0.526 mol) and TBDMSCl
(47.6 g, 0.316 mol) at room temperature. After being stirred for
7.5 h, the reaction was quenched with MeOH. The resulting mixture
was washed with 1 M HCl aq, satd NaHCO3 aq, and brine. The or-
ganic layer was dried over Na2SO4, filtered, and concentrated in
vacuo. The residue was then dissolved in MeOH (500 ml) and 1 M
NaOMe in MeOH (39.4 ml, 39 4 mmol) was added at 0 ꢀC. After
being stirred for 3.5 h, the reaction mixture was neutralized with
1 M HCl aq and AcOEt was added. The organic layer was washed
with 1 M HCl aq (2ꢂ), water and brine, dried over Na2SO4, filtered,
and concentrated in vacuo to give crude methyl 4-O-tert-butyldi-
ded compound 5 as a colorless oil. Yield 211 mg (85%,
a/
b
¼5:3). 1H
NMR (600 MHz, CDCl3) for a-anomer 7.37–7.23 (5H, m, aromatic),
d
5.58 (1H, s, H-1), 4.88 and 4.72 (each 1H, d, Jgem¼11.5 Hz, PhCH2),
4.50 (1H, d, J5,4¼8.2 Hz, H-5), 4.06 (1H, d, J2,3¼8.2 Hz, H-2), 3.87
(1H, dd, J4,3¼8.2 Hz, J4,5¼8.2 Hz, H-4), 3.77 (3H, s, COOCH3), 3.76
(1H, dd, J3,2¼8.2 Hz, J3,4¼8.2 Hz, H-3), 2.70 (1H, s, 4-OH), 1.11–1.03
(28H, m, –Si(i-Pr)2–ꢂ2); 13C NMR (150 MHz, CDCl3)
d for a-anomer
170.4, 128.4, 128.1, 128.0, 127.8, 127.8, 127.8, 92.7, 80.3, 75.1, 74.7,
74.5, 72.3, 52.5, 17.4, 17.3, 17.2, 17.2, 17.2, 17.1, 17.0, 17.0, 13.1, 13.1, 12.8,
12.8; HRMS (positive mode) found: m/z 563.2477 [MþNa]þ, calcd
for C26H44O8Si2Na: 563.2472.
methylsilyl-1,2-O-isopropylidene-a-D-glucofuranosyluronate. The
crude product, benzylimidate (132 ml, 0.526 mol), and MS4A
powder (50 g) were placed in 1000 ml round-bottom flask, and
anhydrous CH2Cl2 (500 ml) was added at room temperature under
Ar. After being stirred for 1 h, the reaction mixture was cooled to
ꢁ30 ꢀC and TBDMSOTf (7.86 ml, 34.2 mmol) was added at the same
temperature. The reaction mixture was further stirred and gradu-
ally warmed to 0 ꢀC. After 15 h, the reaction was quenched by the
addition of EtOH. The resulting mixture was filtered through
a Celite pad and the filtrate was concentrated in vacuo. The residue
was dissolved in CH2Cl2 and the mixture was washed with water
and brine. The organic layer was dried over Na2SO4, filtered, and
concentrated in vacuo to give crude methyl 3-O-benzyl-4-O-tert-
3.6. Methyl 3-O-benzyl-4-O-levulinyl-1,2-O-(1,1,3,3-
tetraisopropyldisiloxanylidene)-D-glucopyranosyluronate (6)
Compound 5 (21.4 g, 39.5 mmol) was dissolved in CH2Cl2
(200 ml) under Ar. LevOH (6.08 ml, 59.4 mmol), EDC$HCl (9.21 g,
59.4 mmol), and DMAP (7.25 g, 59.4 mmol) were then added at
room temperature. After being stirred for 8.5 h, the reaction was
quenched by the addition of water. The organic layer was washed
with satd NaHCO3 aq, 1 M HCl aq, and brine, dried over Na2SO4,
filtered, and concentrated in vacuo. Flash chromatography (silica
gel: 450 g, hexane/EtOAc¼8:1/2:1) afforded compound 6 as
butyldimethylsilyl-1,2-O-isopropylidene-a-D-glucofuranosyluronate.
The crude product was then dissolved in THF (300 ml) and AcOH
(15 ml). The mixture was cooled to ꢁ20 ꢀC and 1 M TBAF in THF
a colorless oil. Yield 21.1 g (84%,
a
/b
¼5:3). 1H NMR (600 MHz,

3956
A. Saito et al. / Tetrahedron 66 (2010) 3951–3962
CDCl3)
d
for
a
-anomer 7.35–7.27 (5H, m, aromatic), 5.58 (1H, d,
Jgem¼11.5 Hz, PhCH2), 4.09 (1H, ddd, J4,3¼8.8 Hz, J4,5¼9.5 Hz,
J4,OH¼2.0 Hz, H-4), 3.91 (1H, d, J5,4¼9.5 Hz, H-5), 3.83 (3H, s,
COOCH3), 3.71 (1H, dd, J3,2¼9.5 Hz, J3,4¼8.8 Hz, H-3), 3.18 (1H, d,
JOH,4¼2.0 Hz, 4-OH),1.03 (9H, s, C(CH3)3), 0.08 (3H, s, CH3), 0.01 (3H,
J1,2¼3.4 Hz, H-1), 5.05 (1H, dd, J4,3¼9.5 Hz, J4,5¼10.1 Hz, H-4), 4.89
and 4.68 (each 1H, d, Jgem¼11.5 Hz, PhCH2), 4.47 (1H, d, J5,4¼10.1 Hz,
H-5), 4.14 (1H, dd, J2,1¼3.4 Hz, J2,3¼8.8 Hz, H-2), 3.84 (1H, dd,
J3,2¼8.8 Hz, J3,4¼9.5 Hz, H-3), 3.72 (3H, s, COOCH3), 2.66–2.58 (2H,
m, CH3C(]O)C2H4C(]O)–), 2.49–2.31 (2H, m, CH3C(]O)
C2H4C(]O)–), 2.15 (3H, s, CH3C(]O)C2H4C(]O)–), 1.17–0.91 (28H,
s, CH3); 13C NMR (150 MHz, CDCl3)
d 169.9,169.9,133.0,129.8, 129.6,
129.6, 128.5, 128.2, 128.2, 128.0, 128.0, 127.8, 127.6, 127.6, 96.3, 80.4,
74.5, 74.2, 74.0, 72.1, 52.7, 25.5, 25.3, 25.2, 17.3, ꢁ4.4, ꢁ5.5; HRMS
(positive mode) found: m/z 539.2078 [MþNa]þ, calcd for
C27H36O8SiNa: 539.2077.
m, –Si(i-Pr)2–ꢂ2); 13C NMR (150 MHz, CDCl3)
d for a-anomer 206.0,
171.6, 167.7, 138.4, 128.2, 128.2, 128.0, 127.7, 127.5, 92.7, 79.3, 76.1,
75.4, 74.9, 68.9, 52.8, 37.6, 29.8, 27.6, 17.4, 17.3, 17.2, 17.2, 17.0, 17.0,
17.0, 16.9, 14.3, 12.7, 12.7, 12.2; HRMS (positive mode) found: m/z
661.2837 [MþNa]þ, calcd for C26H44O8Si2Na: 661.2840.
3.9. Methyl 3-O-benzyl-1,2-O-isopropylidene-a-L-
idofuranosyluronate (10)
3.7. Methyl (tert-butyldimethylsilyl 2-O-benzoyl-3-O-benzyl-
Compound 8 (50.0 mg, 0.159 mmol) was dissolved in CH2Cl2
4-O-levulinyl-
b
-
D
-glucopyranosyl)uronate (7)
(3 ml) and pyridine (50.0 ml, 0.319 mmol) was added at room
temperature under Ar. The mixture was cooled to ꢁ20 ꢀC and
Compound 6 (2.02 g, 3.16 mmol) was dissolved in THF (10 ml)
and AcOH (181 l, 3.16 mmol) was added at room temperature. A
a solution of Tf2O (50.0 ml, 0.638 mmol) in CH2Cl2 (2.0 ml) was then
m
added dropwise over 20 min at the same temperature. After being
stirred for 2 h, the reaction mixture was transferred into separating
funnel. The organic layer was washed with satd NaHCO3 aq, 3% HCl
aq, and brine, dried over Na2SO4, filtered, and concentrated in
vacuo. The residue was then dissolved in anhydrous DMF (5 ml)
and LevONa (43.0 mg, 0.319 mmol) was added at room tempera-
ture under Ar. After being stirred for 4 h, the reaction mixture was
diluted with AcOEt. The organic layer was washed with water (2ꢂ)
and brine, dried over Na2SO4, filtered, and concentrated in vacuo.
The residue was then dissolved in pyridine/AcOH (3:2, 5 ml) and
solution of TBAF in THF (6.32 ml, 1 M, 6.32 mmol) was then added.
The reaction mixture was stirred for 2 h and diluted with CHCl3.
The organic layer was washed with H2O, satd NaHCO3 aq, and
brine, dried over Na2SO4, filtered, and concentrated in vacuo. The
residue was then dissolved in CH2Cl2 (10 ml) and TBDMSCl (715 ml,
4.74 mmol) and MS4AP (1.0 g) were added at room temperature
under Ar. After 1 h, imidazole (645 mg, 9.48 mmol) was then
added. The reaction mixture was stirred for 19 h at ꢁ25 ꢀC and
gradually warmed to 0 ꢀC and further stirred for 2 h. The reaction
was quenched by the addition of MeOH and filtered through
a Celite pad. The filtrate was washed with H2O and brine, dried
over Na2SO4, filtered, and concentrated in vacuo. The residue was
cooled to 0 ꢀC. After addition of hydrazine monohydrate (35.0
ml,
0.738 mmol) at the same temperature, the reaction mixture was
stirred for 0.5 h. The reaction was quenched by the addition of
acetone and the resulting mixture was diluted with AcOEt. The
organic layer was washed with satd NaHCO3 aq (3ꢂ), 10% HCl aq
(2ꢂ), water, and brine, dried over Na2SO4, filtered, and concen-
trated in vacuo. Flash chromatography (silica gel: 5 g, hexane/
EtOAc¼9:1/8:1) afforded compound 10 as a colorless oil. Yield
then dissolved in pyridine (10 ml) and BzCl (550 ml, 4.74 mmol) was
added at room temperature under Ar. After 13 h, the reaction
was quenched by the addition of MeOH and the resulting mixture
was diluted with AcOEt. The organic layer was washed with 1 M
HCl aq, satd NaHCO3 aq, and brine, dried over Na2SO4, filtered, and
concentrated in vacuo. Flash chromatography (silica gel: 100 g,
toluene/EtOAc¼10:1/6:1) afforded compound 7 as a white solid.
27.9 mg (56%, three steps). 1H NMR (600 MHz, CDCl3)
d 7.38–7.27
(5H, m, aromatic), 6.02 (1H, d, J1,2¼4.1 Hz, H-1), 4.74 and 4.53 (each
1H, d, Jgem¼11.6 Hz, PhCH2), 4.68 (1H, d, J2,1¼4.1 Hz, H-2), 4.54–4.52
(3H, m, H-4, H-5), 4.20 (1H, d, J3,4¼4.1 Hz, H-3), 3.75 (3H, s,
–COOCH3), 3.35 (1H, d, JOH,5¼2.7 Hz, 5-OH), 1.49 (3H, s, CH3), 1.35
Yield 1.51 g (78%, three steps). 1H NMR (600 MHz, CDCl3)
d 7.99
(2H, d, J¼8.1 Hz, Bz), 7.99–7.12 (8H, m, aromatic), 5.33 (1H, dd,
J4,3¼9.5 Hz, J4,5¼9.5 Hz, H-4), 5.31 (1H, dd, J2,1¼7.4 Hz, J2,3¼9.5 Hz,
H-2), 4.84 (1H, d, J1,2¼7.4 Hz, H-1), 4.65 and 4.61 (each 1H, d,
Jgem¼11.5 Hz, PhCH2), 4.01 (1H, d, J5,4¼9.5 Hz, H-5), 3.89
(1H, dd, J3,2¼9.5 Hz, J3,4¼9.5 Hz, H-3), 3.75 (3H, s, COOCH3),
2.71–2.66 (2H, m, CH3C(]O)C2H4C(]O)–), 2.59–2.44 (2H, m,
CH3C(]O)C2H4C(]O)–), 2.17 (3H, s, CH3C(]O)C2H4C(]O)–), 0.74
(9H, s, C(CH3)3), 0.09 (3H, s, CH3), 0.00 (3H, s, CH3); 13C NMR
(3H, s, CH3); 13C NMR (150 MHz, CDCl3)
d 171.9, 136.6, 128.5, 128.5,
128.2, 127.9, 127.8, 112.5, 105.1, 82.9, 82.9, 80.1, 72.3, 69.8, 52.7, 27.0,
26.5; HRMS (positive mode) found: m/z 361.1242 [MþNa]þ, calcd
for C17H22O7Na: 361.1263.
3.10. Methyl 3-O-benzyl-L-idopyranosyluronate (11)
(150 MHz, CDCl3)
d 206.1, 171.3, 167.6, 164.7, 137.5, 133.1, 129.7,
129.6, 128.3, 128.2, 128.1, 127.9, 127.6, 96.0, 78.8, 74.5, 73.6, 72.7,
71.3, 52.8, 37.6, 29.8, 29.8, 27.6, 25.2, ꢁ4.3, ꢁ5.5; HRMS (positive
mode) found: m/z 637.2445 [MþNa]þ, calcd for C32H42O10SiNa:
637.2445.
Compound 10 (46.8 mg, 0.138 mmol) was dissolved in TFA/H2O
(9:1, 1.0 ml) and stirred for 2 h at room temperature. After
removal of volatiles, toluene was added and azeotropically
evaporated twice. Flash chromatography (silica gel: 5 g, toluene/
acetone¼3:1/1:1) afforded compound 11 as a brown solid. Yield
3.8. Methyl (tert-butyldimethylsilyl 2-O-benzoyl-3-O-benzyl-
39.1 mg (95%). 1H NMR (600 MHz, CDCl3)
d for b-anomer of pyra-
b-D
-glucopyranosyl)uronate (8)
nose form 7.39–7.30 (5H, m, aromatic), 5.08 (1H, s, H-1), 4.64 (2H, s,
PhCH2), 4.58 (1H, s, H-5), 4.05 (1H, s, H-4), 3.97 (1H, s, H-3), 3.86
Compound 7 (2.60 g, 4.23 mmol) was dissolved in pyridine/
AcOH (3:2, 10 ml) and hydrazine monohydrate (308 l, 6.34 mmol)
(1H, s, H-2), 3.80 (3H, s, COOCH3); 13C NMR (150 MHz, CDCl3)
d for
m
b-anomer 170.4, 137.2, 128.5, 128.1, 127.6, 93.1, 75.3, 74.3, 72.3, 67.5,
was added at room temperature. After 1.5 h, the reaction was
quenched by the addition of acetone and the resulting mixture was
diluted with AcOEt. The organic layer was washed with 1 M HCl aq,
satd NaHCO3, aq, and brine, dried over Na2SO4, filtered, and con-
centrated in vacuo. Flash chromatography (silica gel: 100 g, hexane/
EtOAc¼3:1) afforded compound 8 as a white solid. Yield 1.80 g
67.2, 52.6; HRMS (positive mode) found: m/z 321.0947 [MþNa]þ,
calcd for C14H18O7Na: 321.0950.
3.11. Methyl 3-O-benzyl-1,2-O-(1,1,3,3-
tetraisopropyldisiloxanylidene)-a-L-idopyranosyluronate (12)
(83%). 1H NMR (600 MHz, CDCl3)
7.14 (8H, m, aromatic), 5.22 (1H, dd, J2,1¼7.4 Hz, J2,3¼9.5 Hz, H-2),
4.81 (1H, d, J1,2¼7.4 Hz, H-1), 4.79 and 4.75 (each 1H, d,
d
7.99 (2H, d, J¼7.4 Hz, Bz), 7.57–
To a suspension of compound 11 (12.5 g, 41.9 mmol), TIPDSCl2
(20.1 ml, 62.9 mmol), and MS4Ap (20 g) in anhydrous acetonitrile
(200 ml) was added imidazole (11.4 g, 0.168 mol) at ꢁ45 ꢀC under

A. Saito et al. / Tetrahedron 66 (2010) 3951–3962
3957
Ar. After being stirred for 41 h, volatiles were removed in vacuo.
Flash chromatography (silica gel: 450 g, toluene/EtOAc¼100:1/
30:1) afforded compound 12 as a yellow oil. Yield 17.7 g (78%). 1H
added at room temperature under Ar. Imidazole (2.67 g,
39.2 mmol) was then added to the mixture and the reaction mix-
ture was stirred at ꢁ20 ꢀC. After being stirred for 3 h, the reaction
mixture was warm to room temperature and further stirred for
3.5 h. The reaction was quenched by addition of MeOH and the
resulting mixture was filtered through Celite pad. The filtrate was
washed with H2O and brine, dried over Na2SO4, filtered, and con-
centrated in vacuo. The residue was dissolved in pyridine (50 ml)
and BzCl (3.03 ml, 26.1 mmol) and DMAP (639 mg, 5.23 mmol)
were added at room temperature under Ar. After 19 h, the reaction
was quenched by the addition of MeOH and the resulting mixture
was diluted with AcOEt. The organic layer was washed with 1 M
HCl aq (2ꢂ), satd NaHCO3 aq, and brine, dried over Na2SO4, filtered,
and concentrated in vacuo. Flash chromatography (silica gel: 400 g,
toluene/EtOAc¼80:1) afforded compound 15 as a colorless oil. Yield
NMR (600 MHz, CDCl3) d for a-anomer 7.37–7.30 (5H, m, aromatic),
5.23 (1H, s, H-1), 4.71 and 4.58 (each 1H, d, Jgem¼12.2 Hz, PhCH2),
4.58 (1H, d, J5,4¼1.3 Hz, H-5), 4.50 (1H, dd, J4,5¼1.3 Hz,
J4,OH¼12.2 Hz, H-4), 3.91 (1H, d, J2,3¼3.4 Hz, H-2), 3.88 (1H, d,
J3,2¼3.4 Hz, H-3), 3.88 (1H, d, JOH,4¼12.2 Hz, 4-OH), 3.79 (3H, s,
COOCH3), 1.04–1.01 (28H, m, –Si(i-Pr)2–ꢂ2); 13C NMR (150 MHz,
CDCl3) d 169.1, 137.2, 129.7, 128.5, 128.1, 127.6, 127.6, 95.5, 76.6, 75.7,
72.3, 71.4, 67.5, 52.0, 17.3, 17.3, 17.2, 17.1, 17.1, 17.0, 17.0, 16.9, 14.5,
12.6, 12.2, 12.0; HRMS (positive mode) found: m/z 563.2472
[MþNa]þ, calcd for C26H44O8Na: 563.2472.
3.12. Methyl 3-O-benzyl-4-O-levulinyl-1,2-O-(1,1,3,3-
tetraisopropyldisiloxanylidene)-
a
-L-idopyranosyluronate (13)
5.25 g (65%, two steps). 1H NMR (600 MHz, CDCl3)
d 8.12 (2H, d,
J¼8.1 Hz, Bz), 7.57–7.16 (8H, m, aromatic), 5.23 (1H, s, H-1),
5.22 (1H, s, H-4), 5.19 (1H, s, H-2), 4.81 and 4.77 (each 1H,
d, Jgem¼11.5 Hz, PhCH2), 4.68 (1H, s, H-5), 4.00 (1H, s, H-3),
3.81 (3H, s, COOCH3), 2.58–2.55 (2H, m, CH3C(]O)C2H4C(]O)–),
2.48–2.28 (2H, m, CH3C(]O)C2H4C(]O)–), 2.05 (3H, s,
CH3C(]O)C2H4C(]O)–), 0.80 (9H, s, C(CH3)3), 0.14 (3H, s, CH3), 0.09
To a solution of compound 12 (7.31 g, 13.5 mmol) in anhydrous
DMF (50 ml) were added LevOH (5.54 ml, 54.1 mmol), EDC$HCl
(6.23 g, 54.1 mmol), DMAP (6.61 g, 54.1 mmol), and Et3N (7.54 ml,
54.1 mmol) at room temperature. The reaction mixture was stirred
for 24 h and the reaction was quenched by the addition of MeOH.
After addition of AcOEt, the organic layer was washed with water
(2ꢂ) and brine, dried over Na2SO4, filtered, and concentrated in
vacuo. Flash chromatography (silica gel: 450 g, hexane/
EtOAc¼4:1/2:1) afforded compound 13 as a colorless oil. Yield
(3H, s, CH3); 13C NMR (150 MHz, CDCl3)
d 205.8, 171.7, 167.8, 165.6,
133.1, 129.9, 129.8, 128.5, 128.2, 128.1, 127.7, 93.1, 73.9, 72.9, 72.3,
68.0, 67.0, 52.3, 37.6, 29.5, 29.5, 27.8, 25.5, ꢁ4.0, ꢁ5.2; HRMS
(positive mode) found: m/z 637.2445 [MþNa]þ, calcd for
C32H42O10SiNa: 637.2445.
5.92 g (68%). 1H NMR (600 MHz, CDCl3)
d 7.37–7.30 (5H, m, aro-
matic), 5.18 (1H, s, H-1), 5.09 (1H, dd, J4,3¼2.7 Hz, J4,5¼2.7 Hz, H-4),
4.80 and 4.64 (each 1H, d, Jgem¼12.2 Hz, PhCH2), 4.65 (1H, d,
J5,4¼2.7 Hz, H-5), 3.88 (1H, dd, J3,2¼2.7 Hz, J2,3¼2.7 Hz, H-3), 3.81
(1H, d, J2,3¼2.7 Hz, H-2), 3.77 (3H, s, COOCH3), 2.78–2.62 (3H, m,
CH3C(]O)C2H4C(]O)–), 2.53–2.50 (1H, m, CH3C(]O)C2H4C(]O)–
), 2.17 (3H, s, CH3C(]O)C2H4C(]O)–),1.04–1.01 (28H, m, –Si(i-Pr)2–
3.15. Methyl (tert-butyldimethylsilyl 2-O-benzoyl-3-O-benzyl-
b-L
-idopyranosyl)uronate (16)
Compound 15 (64.6 mg, 0.104 mmol) was dissolved in pyridine/
AcOH (3:2, 1 ml) and hydrazine monohydrate (7.60 ml, 0.157 mmol)
ꢂ2); 13C NMR (150 MHz, CDCl3)
d
206.2, 172.0, 168.0, 137.3, 128.4,
was added at room temperature. After 5 h, the reaction was
quenched by addition of acetone and the resulting mixture was
diluted with AcOEt. The organic layer was washed with 1 M HCl aq,
satd NaHCO3, aq, and brine, dried over Na2SO4, filtered, and con-
centrated in vacuo. Flash chromatography (silica gel: 5 g, toluene/
EtOAc¼50:1/30:1) afforded compound 16 as a colorless oil. Yield
128.4, 127.9, 127.7, 127.7, 96.0, 76.0, 73.2, 72.6, 70.3, 67.4, 52.1, 37.7,
29.6, 27.9, 17.3, 17.3, 17.3, 17.1, 17.1, 17.0, 14.4, 12.7, 12.5, 12.4; HRMS
(positive mode) found: m/z 661.2820 [MþNa]þ, calcd for
C31H50O10Si2Na: 661.2840.
3.13. Methyl 3-O-benzyl-4-O-levulinyl-
L
-idopyranosyl-
48.5 mg (89%). 1H NMR (600 MHz, CDCl3)
d
8.00 (2H, d, J¼7.4 Hz,
uronate (14)
Bz), 7.59–7.16 (8H, m, aromatic), 5.28 (1H, d, J2,3¼2.7 Hz, H-2), 5.25
(1H, s, H-1), 4.77 and 4.73 (each 1H, d, Jgem¼11.5 Hz, PhCH2), 4.61
(1H, d, J5,4¼2.0 Hz, H-5), 4.06 (1H, dd, J4,5¼2.0 Hz, J4,OH¼11.5 Hz, H-
4), 3.99 (1H, d, J3,2¼2.7 Hz, H-3), 3.82 (3H, s, COOCH3), 3.08 (1H, d,
JOH,4¼11.5 Hz, OH), 0.80 (9H, s, C(CH3)3), 0.14 (3H, s, CH3), 0.08 (3H,
Compound 13 (9.43 g, 14.7 mmol) was dissolved in THF (150 ml)
and AcOH (4.22 ml, 73.8 mmol) was added at room temperature. A
solution of TBAF in THF (29.5 ml, 1 M, 29.5 mol) was then added.
After being stirred for 2.5 h, the reaction mixture was diluted with
AcOEt. The organic layer was washed with H2O, satd NaHCO3 aq,
and brine, dried over Na2SO4, filtered, and concentrated in vacuo.
Flash chromatography (silica gel: 300 g, toluene/EtOAc¼10:1/1:1)
s, CH3); 13C NMR (150 MHz, CDCl3)
d 169.0, 165.4, 137.0, 133.3, 129.7,
129.4, 128.5, 128.4, 128.1, 127.8, 93.1, 75.9, 74.1, 72.6, 69.4, 67.8, 52.2,
25.4, ꢁ4.1, ꢁ5.3; HRMS (positive mode) found: m/z 539.2077
[MþNa]þ, calcd for C27H36O8SiNa: 539.2077.
afforded compound 14 as a colorless oil. Yield 5.28 g (90%,
a
/
b
¼1:2).
1H NMR (600 MHz, CDCl3)
d
for -anomer 7.39–7.17 (5H, m, aro-
a
3.16. 4-tert-Butylphenyl 3,4,6-tri-O-acetyl-2-azido-2-deoxy-1-
matic), 5.24 (1H, s, H-4), 5.04 (1H, d, J1,OH¼5.4 Hz, H-1), 4.75 and
4.65 (each 1H, d, Jgem¼11.5 Hz, PhCH2), 4.68 (1H, s, H-5), 4.12 (1H, d,
JOH,1¼5.4 Hz, OH), 3.95 (1H, s, H-3), 3.79 (3H, s, COOCH3), 3.68 (1H,
s, H-2), 2.78–2.72 (2H, m, CH3C(]O)C2H4C(]O)–), 2.55–2.52 (2H,
m, CH3C(]O)C2H4C(]O)–), 2.19 (3H, s, CH3C(]O)C2H4C(]O)–);
thio-D-glucopyranoside (19)
Compound 18 (5.17 g, 13.8 mmol), 4-tert-butylthiophenol
(9.56 ml, 55.4 mmol), and MSAW300 (10 g) were suspended in
anhydrous CH2Cl2 (100 ml) under Ar. After being stirred for 0.5 h,
the mixture was cooled to 0 ꢀC. TBDMSOTf (5.00 ml, 27.7 mmol)
was added at the same temperature. The reaction mixture was
gradually warmed to room temperature and stirred for 3 days. The
reaction mixture was further stirred for 1 day at 60 ꢀC and the re-
action was quenched by the addition of water. The resulting mix-
ture was filtered through Celite pad. The filtrate was washed with
water, satd NaHCO3 aq, and brine, dried over Na2SO4, filtered, and
concentrated in vacuo. Flash chromatography (silica gel: 300 g,
hexane/AcOEt¼8:1/2:1) afforded compound 18 as a brown oil:
13C NMR (150 MHz, CDCl3)
d for a-anomer 206.6, 171.1, 168.0, 136.8,
128.5, 128.2, 127.7, 93.0, 74.3, 72.7, 72.4, 68.0, 67.8, 52.6, 37.9, 29.6,
27.8; HRMS (positive mode) found: m/z 419.1319 [MþNa]þ, calcd for
C19H24O9Na: 419.1318.
3.14. Methyl (tert-butyldimethylsilyl 2-O-benzoyl-3-O-benzyl-
4-O-levulinyl-b-L-idopyranosyl)uronate (15)
Compound 14 (5.18 g, 13.0 mmol) was dissolved in CH2Cl2
(100 ml) and TBDMSCl (3.93 g, 26.1 mmol) and MS4AP (10 g) were
4.82 g (73%,
a
/b
¼4:1). 1H NMR (600 MHz, CDCl3)
d for a-anomer

3958
A. Saito et al. / Tetrahedron 66 (2010) 3951–3962
7.42–7.33 (4H, m, aromatic), 5.59 (1H, d, J1,2¼5.4 Hz, H-1), 5.35 (1H,
dd, J3,2¼9.5 Hz, J3,4¼10.2 Hz, H-3), 5.06 (1H, dd, J4,3¼10.2 Hz,
J4,5¼8.8 Hz, H-4), 4.65–4.62 (1H, m, H-5), 4.32 (1H, dd,
J6a,6b¼12.9 Hz, J6a,5¼5.4 Hz, H-6a), 4.08–4.03 (2H, m, H-2, H-6b),
2.10 (3H, s, CH3), 2.06 (3H, s, CH3), 2.04 (3H, s, CH3), 1.30 (9H, s,
3.19. 4-tert-Butylphenyl 2-azido-6-O-tert-butyldiphenylsilyl-
2-deoxy-4-O-levulinyl-3-O-(4-methoxybenzyl)-1-thio-D-
glucopyranoside (22)
To a solution of compound 4-tert-butylphenyl 2-azido-2-deoxy-
4,6-O-isopropylidene-3-O-(4-methoxybenzyl)-1-thio- -glucopyr-
C(CH3)3); 13C NMR (150 MHz, CDCl3)
d
for
a-anomer 170.5, 169.8,
D
152.3,134.3,132.4,128.6,126.3, 86.7, 72.0, 68.6, 68.3, 61.8, 61.5, 34.5,
31.1, 20.6, 20.6, 20.6; HRMS (positive mode) found: m/z 502.1631
[MþNa]þ, calcd for C22H29N3O7SNa: 502.1624.
anoside (12.2 g, 25.7 mmol) in anhydrous DMF (100 ml) were
added TBDPSCl (9.92 ml, 38.6 mmol) and imidazole (5.26 g,
7.73 mmol) at room temperature under Ar. After 5 h, the reaction
was quenched by addition of methanol and the mixture was diluted
with AcOEt. The organic layer was washed with water and brine,
dried over Na2SO4, filtered, and concentrated in vacuo. The residue
was then dissolved in anhydrous DMF (120 ml) and LevOH (10.5 ml,
0.103 mol), EDC$HCl (11.9 g, 77.2 mmol), and DMAP (9.44 g,
77.2 mmol) were added at room temperature under Ar. After 26 h,
the reaction was quenched by the addition of MeOH and the mix-
ture was diluted with AcOEt. The organic layer was washed with
water and brine, dried over Na2SO4, filtered, and concentrated in
vacuo. Flash chromatography (silica gel: 450 g, hexane/
EtOAc¼8:1/3:1) afforded compound 22 as a brown oil. Yield
3.17. 4-tert-Butylphenyl 2-azido-2-deoxy-4,6-O-
isopropylidene-1-thio-D-glucopyranoside (20)
To a solution of compound 19 (49.5 g, 0.103 mol) in methanol
(400 ml) was added 1 M NaOMe in MeOH (100 ml, 0.100 mol) at
room temperature. After 3 h, the reaction was quenched by ad-
dition of Dowex 50W (Hþ). After removal of insoluble materials
by filtration, the filtrate was concentrated in vacuo. The residue
was then dissolved in acetone (400 ml) and 2-methoxypropene
(29.6 ml, 0.309 mmol) and CSA (7.19 g, 30.9 mmol) were added at
room temperature under Ar. After 12 h, AcOEt was added. The
organic layer was washed with water and brine, dried over
Na2SO4, filtered, and concentrated in vacuo. Flash chromatogra-
phy (silica gel: 450 g, hexane/EtOAc¼10:1/3:1) afforded com-
18.6 g (89%, two steps,
a
/b
¼10:3). 1H NMR (600 MHz, CDCl3)
d for a-
anomer 7.45–7.22 (16H, m, aromatic), 6.88 (2H, d, J¼8.8 Hz, MPM),
5.55 (1H, d, J1,2¼5.4 Hz, H-1), 5.16 (1H, dd, J4,3¼9.5 Hz, J4,5¼9.5 Hz,
H-4), 4.76 and 4.62 (each 1H, d, Jgem¼10.8 Hz, PhCH2), 4.41–
4.37 (1H, m, H-5), 3.94 (1H, dd, J2,1¼5.4 Hz, J2,3¼10.2 Hz, H-2),
3.80–3.65 (6H, m, H-3, H-6a, H-6b, OCH3), 2.61–2.58 (2H, m,
CH3C(]O)C2H4C(]O)–), 2.37–2.34 (2H, m, CH3C(]O)C2H4C(]O)–),
2.15 (3H, s, CH3), 1.27 (9H, s, C(CH3)3), 1.01 (9H, s, C(CH3)3); 13C NMR
pound 20 as a brown oil. Yield 29.8 g (74%, two steps,
a
/
b
¼5:1).
1H NMR (600 MHz, CDCl3)
d
for -anomer 7.42–7.34 (4H, m,
a
aromatic), 5.50 (1H, d, J1,2¼5.4 Hz, H-1), 4.25–4.21 (1H, m, H-5),
3.94 (1H, dd, J3,2¼9.5 Hz, J3,4¼8.8 Hz, H-3), 3.88–3.83 (2H, m, H-
2, H-6a), 3.77 (1H, d, J6b,6a¼10.8 Hz, H-6b), 3.62 (1H, dd,
J4,3¼8.8 Hz, J4,5¼9.5 Hz, H-4), 2.70 (1H, s, 3-OH), 1.52 (3H, s, CH3),
1.46 (3H, s, CH3), 1.30 (9H, s, C(CH3)3); 13C NMR (150 MHz, CDCl3)
(150 MHz, CDCl3)
d for a-anomer 205.9, 171.2, 135.7, 135.5, 132.0,
129.9127.6, 127.5, 126.1, 113.8, 87.2, 78.9, 74.8, 71.8, 70.5, 63.8, 62.4,
55.2, 37.7, 31.1, 29.8, 27.8, 26.6; HRMS (positive mode) found: m/z
832.3429 [MþNa]þ, calcd for C45H55N3O7SSiNa: 832.3428.
d
for a-anomer 151.3, 132.6, 132.1, 126.2, 100.1, 88.0, 74.3, 70.9,
64.2, 64.0, 61.9, 34.5, 31.1, 28.9, 19.1; HRMS (positive mode)
found: m/z 416.1628 [MþNa]þ, calcd for C19H27N3O4SNa:
416.1620.
3.20. 2-Azido-6-O-tert-butyldiphenylsilyl-2-deoxy-4-O-
levulinyl-3-O-(4-methoxybenzyl)-
D
-glucopyranose
To a solution of compound 23 (75.5 mg, 93.2
mmol) in acetone/
H2O (5:2, 1.4 ml) was added NCS (87.1 mg, 0.652 mmol) at room
temperature. After 12 h, the reaction was quenched by the ad-
dition of 10% Na2S2O3 aq and the mixture was diluted with
AcOEt. The organic layer was washed with 10% Na2S2O3 aq and
brine, dried over Na2SO4, filtered, and concentrated in vacuo.
Flash chromatography (silica gel: 5 g, hexane/EtOAc¼6:1/4:1)
3.18. 4-tert-Butylphenyl 2-azido-2-deoxy-3-O-(4-
methoxybenzyl)-1-thio-D-glucopyranoside (21)
To a solution of compound 20 (120 mg, 0.304 mmol) in an-
hydrous DMF (5 ml) were added MPMCl (82.7 l, 0.610 mmol)
m
and NaH (18.3 mg, 0.762 mmol) at 0 ꢀC under Ar. The reaction
mixture was stirred and gradually warmed to room temperature.
After 4.5 h, the reaction was quenched by addition of methanol
and the reaction mixture was diluted with AcOEt. The organic
layer was washed with water and brine, dried over Na2SO4, fil-
tered, and concentrated in vacuo. The residue was then dissolved
in CH2Cl2 (1 ml) and AcOH/H2O (8:1, 9 ml) was added at room
temperature. After 4 h, the reaction was quenched by the addi-
tion of 1 M NaOH aq. The organic layer was washed with 1 M
NaOH aq (2ꢂ), and brine, dried over Na2SO4, filtered, and
concentrated in vacuo. Flash chromatography (silica gel: 5 g,
hexane/EtOAc¼1:1) afforded compound 4-tert-butylphenyl 2-
azido-2-deoxy-4,6-O-isopropylidene-3-O-(4-methoxybenzyl)-1-thio-
afforded
2-azido-6-O-tert-butyldiphenylsilyl-2-deoxy-4-O-levu-
linyl-3-O-(4-methoxybenzyl)-
D
-glucopyranose as a colorless oil.
Yield 44.8 mg (73%,
a/
b
¼5:3). 1H NMR (600 MHz, CDCl3)
d for a-
anomer 7.69–7.23 (12H, m, aromatic), 6.87 (2H, d, J¼8.8 Hz,
MPM), 5.28 (1H, dd, J1,2¼3.4 Hz, J1,OH¼3.4 Hz, H-1), 5.14 (1H, dd,
J4,3¼9.5 Hz, J4,5¼10.2 Hz, H-4), 4.71 and 4.60 (each 1H, d,
Jgem¼10.8 Hz, PhCH2), 4.40–3.97 (1H, m, H-5), 3.98 (1H, dd,
J3,2¼9.5 Hz, J3,4¼9.5 Hz, H-3), 3.79 (3H, s, OCH3), 3.70–3.66 (2H,
m, H-6a, H-6b), 3.46 (1H, dd, J2,1¼3.4 Hz, J2,3¼9.5 Hz, H-2), 2.84
(1H, d, OH), 2.61–2.58 (2H, m, CH3C(]O)C2H4C(]O)–), 2.37–2.32
(2H, m, CH3C(]O)C2H4C(]O)–), 2.14 (3H, s, CH3), 1.02 (9H, s,
C(CH3)3); 13C NMR (150 MHz, CDCl3)
d for a-anomer 206.1, 171.2,
135.8, 135.7, 135.6, 135.6, 129.8, 129.7, 129.6, 127.5, 127.5, 113.7,
91.8, 77.3, 74.4, 70.7, 70.5, 63.5, 62.9, 55.2, 37.7, 29.8, 27.8, 26.7;
HRMS (positive mode) found: m/z 684.2713 [MþNa]þ, calcd for
C35H43N3O8SiNa: 684.2717.
D
-glucopyranoside as a brown oil. Yield 108 mg (75%, two steps,
a
/b
¼4:1). 1H NMR (600 MHz, CDCl3)
d for a-anomer 7.44–7.29
(6H, m, aromatic), 6.90 (2H, d, J¼8.8 Hz, MPM), 5.51 (1H, d,
J1,2¼5.4 Hz, H-1), 4.94 and 4.69 (each 1H, d, Jgem¼11.5 Hz, PhCH2),
4.24 (1H, dd, J3,2¼8.8 Hz, J3,4¼8.1 Hz, H-3), 3.87–3.78 (6H, m, H-2,
H-6a, H-6b, OCH3), 3.64–3.61 (2H, m, H-4, H-5), 1.30 (9H, s,
3.21. 2-Azido-6-O-tert-butyldiphenylsilyl-2-deoxy-4-O-
levulinyl-3-O-(4-methoxybenzyl)-D-glucopyranosyl
trichloroacetimidate (24)
C(CH3)3); 13C NMR (150 MHz, CDCl3)
d
for
a-anomer 151.4, 132.6,
129.8, 126.2, 114.1, 87.3, 81.1, 72.1, 70.8, 63.7, 62.0, 55.2, 34.5, 31.1;
HRMS (positive mode) found: m/z 496.1886 [MþNa]þ, calcd for
C24H31N3O5SNa: 496.1882.
To a solution of 2-azido-6-O-tert-butyldiphenylsilyl-2-deoxy-
4-O-levulinyl-3-O-(4-methoxybenzyl)- -glucopyranose (5.53 g,
D

A. Saito et al. / Tetrahedron 66 (2010) 3951–3962
3959
0
0
0
8.36 mmol) in CH2Cl2 (15 ml) were added trichloroacetonitrile
(2.79 ml, 27.8 mmol) and Cs2CO3 (908 mg, 2.73 mmol) at 0 ꢀC.
After being stirred for 2 h, the reaction mixture was filtered
through a Celite pad. The filtrate was concentrated in vacuo to
afford glycosyl imidate 24, which was used to the next reaction
without further purification.
J1 ,2 ¼3.4 Hz, H-1 ), 4.51 (1H, d, J5,4¼2.0 Hz, H-5), 4.30 (1H, d,
J3,4¼3.4 Hz, H-3), 3.92–3.90 (3H, m, H-4, PhCH2), 3.79–3.75 (4H,
m, H-50, OCH3), 3.67–3.66 (2H, m, H-6a0, H-6b0), 3.55 (1H, dd,
0
0
0
0
0
J3 ,2 ¼9.5 Hz, J3 ,4 ¼9.5 Hz, H-3 ), 3.45 (3H, s, OCH3), 3.31 (1H, dd,
J2 ,1 ¼3.4 Hz,
J2 ,3 ¼9.5 Hz,
H-20),
2.63–2.61
(2H,
m,
0
0
0
0
CH3C(]O)C2H4C(]O)–), 2.39–2.37 (2H, m, CH3C(]O)C2H4C(]O)–
), 2.17 (3H, s, CH3C(]O)C2H4C(]O)–), 1.00 (9H, s, C(CH3)3), 0.80
(9H, s, C(CH3)3), 0.14 (3H, s, CH3), 0.06 (3H, s, CH3); 13C NMR
3.22. Methyl [2-O-azido-6-O-tert-butyldiphenylsilyl-2-O-
deoxy-4-O-levulinyl-3-O-(4-methoxybenzyl)-
glucopyranosyl]-(1/4)-(tert-butyldimethylsilyl 2-O-benzoyl-
3-O-benzyl- -glucopyranosid)uronate (25)
a
-
D
-
(150 MHz, CDCl3) d 206.1, 170.7, 168.3, 166.5, 135.8, 135.7, 130.1,
129.6, 129.5, 129.5, 129.0, 128.5, 128.4, 128.2, 128.0, 127.5, 127.4,
113.6, 99.2, 93.4, 77.9, 75.1, 74.1, 73.7, 73.7, 73.0, 71.1, 69.7, 68.9,
63.4, 61.5, 55.2, 51.8, 37.7, 30.9, 29.8, 29.2, 27.8, 26.6, 25.5, ꢁ4.0,
ꢁ5.3; HRMS (positive mode) found: m/z 1182.4759 [MþNa]þ,
calcd for C62H77N3O15Si2Na: 1182.4791.
b-D
The glycosyl donor 24 (8.38 mmol), glycosyl accepter
8
(2.85 g, 5.51 mmol), and MS4A powder (7.0 g) were then sus-
pended in anhydrous toluene (70 ml) under Ar. After being
stirred for 2 h, the mixture was cooled to ꢁ20 ꢀC. TBDMSOTf
3.24. Methyl [2-O-azido-6-O-tert-butyldiphenylsilyl-2-O-
deoxy-4-O-levulinyl-3-O-(4-methoxybenzyl)-a-D-
(506
m
l, 2.20 mmol) was added at the same temperature. The
reaction mixture was stirred and gradually warmed to 0 ꢀC. After
5 h, the reaction was quenched by the addition of water. The
resulting mixture was filtered through a Celite pad. The filtrate
was washed with water, satd NaHCO3 aq, and brine, dried over
Na2SO4, filtered, and concentrated in vacuo. Flash chromatog-
raphy (silica gel: 300 g, toluene/AcOEt¼100:1/20:1) afforded
compound 25 as a brown oil. Yield 5.29 g (83%). 1H NMR
glucopyranosyl]-(1/4)-(2-O-benzoyl-3-O-benzyl-D-
glucopyranosyl)uronate (27)
To a solution of compound 25 (55.7 mg, 48.0 mmol) in THF
(1 ml) were added AcOH (5.5
ml, 96.0 mmol) and 1 M TBAF in THF
(48.0 l, 48.0 mol) at room temperature. After being stirred for
m
m
12 h, the reaction mixture was poured into AcOEt. The resulting
mixture was washed with water and brine, dried over Na2SO4,
filtered, and concentrated in vacuo. Flash chromatography (silica
gel: 5 g, toluene/EtOAc¼10:1/8:1) afforded compound 27 as
(600 MHz, CDCl3)
d
8.04 (2H, d, J¼8.1 Hz, Bz), 7.65–7.19 (20H, m,
0
0
aromatic), 6.88 (2H, d, J¼8.8 Hz, MPM), 5.51 (1H, d, J1 ,2 ¼3.4 Hz,
H-10), 5.36–5.31 (2H, m, H-2, H-40), 4.87 (1H, d, J1,2¼7.4 Hz, H-1),
4.79 and 4.72 (each 1H, d, Jgem¼10.8 Hz, PhCH2), 4.72 and 4.61
(each 1H, d, Jgem¼10.8 Hz, PhCH2), 4.28 (1H, dd, J4,3¼8.8 Hz,
J4,5¼9.5 Hz, H-4), 4.07 (1H, d, J5,4¼9.5 Hz, H-5), 4.01 (1H, dd,
a colorless oil. Yield 39.5 mg (78%,
CDCl3) for
a
/
b
¼5:1). 1H NMR (600 MHz,
d
a
-anomer 8.11 (2H, d, J¼7.4 Hz, Bz), 7.66–7.19 (20H,
m, aromatic), 6.86 (2H, d, J¼8.8 Hz, MPM), 5.65 (1H, d0d,
0
0
0
0
J3,2¼8.8 Hz, J3,4¼8.8 Hz, H-3), 3.90 (1H, dd, J3 ,2 ¼10.2 Hz,
J1,2¼3.4 Hz, J1,OH¼5.4 Hz, H-1), 5.37 (1H, d, J10,2 ¼3.4 Hz, H-1 ),
0
0
0
0
0
0
0
0
0
J3 ,4 ¼9.5 Hz, H-3 ), 30.79 (3H, s, OCH3), 3.69 (1H, dd, J6a ,5 ¼1.3 Hz,
5.26 (1H, dd, J4 ,5 ¼10.2 Hz, J4 ,3 ¼9.5 Hz, H-4 ), 5.16 (1H, dd,
J2,3¼8.1 Hz, J2,1¼3.4 Hz, H-2), 4.85 (2H, s, PhCH2), 4.70 (1H, d,
J5,4¼7.1 Hz, H-5), 4.46 and 4.39 (each 1H, d, Jgem¼10.2 Hz, PhCH2),
4.37 (1H, dd, J3,4¼7.4 Hz, J3,2¼8.1 Hz, H-3), 4.19 (1H, dd,
J4,5¼7.1 Hz, J4,3¼7.4 Hz, H-4), 3.81–3.77 (4H, m, H-30, OCH3),
3.69–3.62 (3H, m, H-50, H-6a0, H-6b0), 3.54 (3H, s, OCH3), 3.32
0
0
0
0
0
0
J6a ,6b ¼11.8 Hz, H-6a ), 3.64 (1H, dd, J6b ,5 ¼1.3 Hz, J6b ,6a ¼11.8 Hz,
H-6b0), 3.56–3.53 0(4H, m, OCH3, H-50), 3.34 (1H, dd, J2 ,1 ¼3.4 Hz,
0
0
0
0
J2 ,3 ¼10.2 Hz, H-2 ), 2.66–2.63 (2H, m, CH3C(]O)C2H4C(]O)–),
2.42–2.36 (2H, m, CH3C(]O)C2H4C(]O)–), 2.17 (3H, s,
CH3C(]O)C2H4C(]O)–), 1.02 (9H, s, C(CH3)3), 0.74 (9H, s,
C(CH3)3), 0.06 (3H, s, CH3), 0.00 (3H, s, CH3); 13C NMR (150 MHz,
(1H, dd, J2 ,3 ¼10.2 Hz, J2 ,1 ¼3.4 Hz, H-20), 3.23 (1H, d,
JOH,1¼5.4 Hz, OH), 2.65–2.62 (2H, m, CH3C(]O)C2H4C(]O)–),
2.42–2.39 (2H, m, CH3C(]O)C2H4C(]O)–), 2.16 (3H, s,
CH3C(]O)C2H4C(]O)–), 1.01 (9H, s, C(CH3)3); 13C NMR
0
0
0
0
CDCl3)
d 206.3, 168.4, 163.7, 135.7, 135.6, 135.6, 129.8, 129.6,
129.6, 129.6, 129.5, 128.4, 128.3, 127.8, 127.8, 127.7, 127.6, 127.5,
113.7, 97.3, 95.9, 82.2, 77.3, 74.8, 74.7, 74.3, 74.1, 73.7, 70.8, 69.6,
62.8, 60.7, 55.2, 52.4, 37.7, 29.8, 27.8, 26.6, 25.2, ꢁ4.4, ꢁ5.4;
HRMS (positive mode) found: m/z 1182.4793 [MþNa]þ, calcd for
C62H77N3O15Si2Na: 1182.4791.
(150 MHz, CDCl3)
d 206.1, 170.9, 169.2, 159.2, 135.7, 135.6, 130.1,
129.8, 129.6, 129.6, 129.5, 129.3, 128.6, 128.4, 128.4, 127.8, 127.7,
127.5, 127.5, 113.7, 98.3, 89.9, 77.3, 75.1, 74.3, 74.1, 73.3, 72.4, 71.5,
71.0, 70.0, 62.8, 61.7, 55.2, 52.4, 37.7, 29.8, 27.8, 26.6; HRMS
(positive mode) found: m/z 1068.3932 [MþNa]þ, calcd for
C56H63N3O15SiNa: 1068.3926.
3.23. Methyl [2-O-azido-6-O-tert-butyldiphenylsilyl-2-O-
deoxy-4-O-levulinyl-3-O-(4-methoxybenzyl)-
glucopyranosyl]-(1/4)-(tert-butyldimethylsilyl 2-O-benzoyl-
3-O-benzyl- -idopyranosid)uronate (26)
a-D-
b
-D
3.25. Benzyl (2-O-azido-6-O-tert-butyldiphenylsilyl-2-O-
deoxy-4-O-levulinyl-3-O-(4-methoxybenzyl)-
a-D-
The glycosyl imidate 24 (0.375 mmol), glycosyl accepter 15
(97.1 mg, 0.187 mmol), and MS4A powder (800 mg) were then
suspended in anhydrous CH2Cl2 (8.0 ml) under Ar. After being
stirred for 3 h, the mixture was cooled to ꢁ20 ꢀC. TBDMSOTf
glucopyranosyl)-(1/4)-(methyl 2-O-benzoyl-3-O-benzyl-b-D-
glucopyranosyluronate)-(1/6)-2,3,4-tetra-O-benzyl-b-D-
glucopyranoside (30)
(21.5
m
l, 93.7 mmol) was added at the same temperature. The
To a solution of 27 (54.1 mg, 51.7
added trichloroacetonitrile (51.8
(16.8 mg, 51.7 mol) at room temperature. After being stirred for
mmol) in CH2Cl2 (2 ml) were
reaction mixture was stirred and gradually warmed to room
temperature. After 18 h, the reaction was quenched by the addi-
tion of water. The resulting mixture was filtered through a Celite
pad. The filtrate was washed with water, and brine, dried over
Na2SO4, filtered, and concentrated in vacuo. Flash chromatography
(silica gel: 20 g, toluene/AcOEt¼100:1/60:1) afforded compound
26 as a brown oil. Yield 169 mg (77%). 1H NMR (600 MHz, CDCl3)
ml, 517 mmol) and Cs2CO3
m
1 h, the reaction mixture was filtered through Celite pad. The
filtrate was concentrated in vacuo to give glycosyl imidate 28.
The glycosyl imidate 28 (51.7 mmol), glucose moiety 29 (55.9 mg,
0.103 mmol), and MS4A powder (400 mg) were then suspended
in anhydrous CH2Cl2 (4 ml) under Ar. After being stirred for
d
8.21 (2H, d, J¼7.4 Hz, Bz), 7.66 (18H, m, aromatic), 7.02 (2H, d,
2.5 h, the mixture was cooled to ꢁ78 ꢀC. TMSOTf (5.74
ml,
J¼8.8 Hz, MPM), 6.80 (2H, d, J¼8.8 Hz, MPM), 5.28 (1H, dd,
25.8 mmol) was then added at the same temperature. After 23 h,
0
0
0
0
0
J4 ,3 ¼9.5 Hz, J4 ,5 ¼9.5 Hz, H-4 ), 5.19 (1H, s, H-1), 5.09 (1H, s, H-2),
4.84 and 4.76 (each 1H, d, Jgem¼11.5 Hz, PhCH2), 4.68 (1H, d,
the reaction was quenched by the addition of water. The
resulting mixture was filtered through a Celite pad. The filtrate

3960
A. Saito et al. / Tetrahedron 66 (2010) 3951–3962
was washed with water, and brine, dried over Na2SO4, filtered,
and concentrated in vacuo. Flash chromatography (silica gel: 5 g,
toluene/AcOEt¼50:1/10:1) afforded compound 30 as a color-
less oil. Yield 54.7 mg (68%, two steps). 1H NMR (600 MHz,
3.27. Benzyl (2-O-azido-6-O-tert-butyldiphenylsilyl-2-O-
deoxy-4-O-levulinyl-3-O-(4-methoxybenzyl)-
glucopyranosyl)-(1/4)-(methyl 2-O-benzoyl-3-O-benzyl-
a-D-
b-L-
idopyranosyluronate)-(1/6)-2,3,4-tetra-O-benzyl-b-D-
CDCl3)
d
7.98 (2H, d, J¼6.7 Hz, Bz), 7.65–7.13 (40H, m, aro0matic),
glucopyranoside (33)
0
0
6.88 (2H, d, J¼8.8 Hz, MPM), 5.46 (1H, d, J1 ,2 ¼3.4 Hz, H-1 ), 5.43
(1H, dd, J2 ,3 ¼8.8 Hz, J2 ,1 ¼7.4 Hz, H-20), 5.35 (1H, dd,
To a solution of 31 (112 mg, 107
added trichloroacetonitrile (107
(34.8 mg, 107
mol) at 0 ꢀC. The reaction mixture was stirred and
m
mol) in CH2Cl2 (8 ml) were
0
0
0
0
00
00 00
00 00
J4 ,5 ¼9.5 Hz, J4 ,3 ¼9.5 Hz, H-4 ), 4.87 and 4.69 (each 1H, d,
Jgem¼10.8 Hz, PhCH2), 4.86 and 4.68 (each 1H, d, Jgem¼12.2 Hz,
PhCH2), 4.79 and 4.70 (each 1H, d, Jgem¼10.2 Hz, PhCH2), 4.73
ml, 1.07 mmol) and Cs2CO3
m
gradually warmed to room temperature. After being stirred for
6 h, the reaction mixture was filtered through Celite pad. The
filtrate was concentrated in vacuo to give glycosyl imidate 32.
(1H, d, J1 ,2 ¼7.4 Hz, H-10), 4.69 and 4.64 (each 1H, d,
Jgem¼10.8 Hz, PhCH2), 4.65 and 4.41 (each 1H, d, Jgem¼12.2 Hz,
PhCH2), 4.60 and 4.44 (each 1H, d, Jgem¼10.8 Hz, PhCH2), 4.36
0
0
The glycosyl imidate 32 (107 mmol), glucose moiety 29 (116 mg,
0
0
0
0
(1H, d, J1,2¼7.4 Hz, H-1), 4.26 (1H, dd, J4 ,5 ¼9.5 Hz, J4 ,3 ¼8.8 Hz,
214 mmol), and MS4A powder (1.0 g) were then suspended in
anhydrous CH2Cl2 (10 ml) under Ar. After being stirred for 2.5 h,
the mixture was cooled to ꢁ20 ꢀC. TMSOTf (3.8
H-40), 4.10 (1H, dd, J6a,6b¼10.8 Hz, J6a,5¼1.3 Hz, H-6a), 4.05 (1H, d,
0
0
0
0
0
0
0
0
J5 ,4 ¼9.5 Hz, H-5 ), 3.97 (1H, dd, J3 ,4 ¼8.8 Hz, J3 ,2 ¼8.8 Hz, H-3 ),
ml, 21 mmol) was
3.90 (1H, dd, J3 ,4 ¼9.5 Hz, J3 ,2 ¼9.5 Hz, H-300), 3.78 (3H, s,
then added at the same temperature. After 2.5 h, the reaction
was quenched by the addition of water. The resulting mixture
was filtered through a Celite pad. The filtrate was washed with
water, satd NaHCO3 aq, and brine, dried over Na2SO4, filtered,
and concentrated in vacuo. Flash chromatography (silica gel:
15 g, toluene/AcOEt¼50:1/30:1) afforded compound 33 as
a colorless oil. Yield 103 mg (62%, two steps). 1H NMR (600 MHz,
00 00
00 00
00
00
00
00 00
OCH3), 3.69 (1H, dd, J6a ,6b ¼11.5 Hz, J6a ,5 ¼001.3 Hz, H-6a ), 3.64
00
00
00 00
(1H, dd, J6b ,6a ¼11.5 Hz, J6b ,5 ¼2.7 Hz, H-6b ), 3.59–3.52 (6H, m,
H-3, H-6b, H-500, OCH3), 3.44–3.41 (1H, m, H-5), 3.40 (1H, dd,
J2,3¼8.1 Hz, J2,1¼7.4 Hz, H-2), 3.34–3.30 (2H, m, H-4, H-200), 2.66–
2.63 (2H, m, CH3C(]O)C2H4C(]O)–), 2.42–2.39 (2H, m,
CH3C(]O)C2H4C(]O)–), 2.16 (3H, s, CH3C(]O)C2H4C(]O)–), 1.01
(9H, s, C(CH3)3); 13C NMR (150 MHz, CDCl3)
d
206.1, 168.3, 164.8,
CDCl3)
d
8.17 (2H, d, J¼8.1 Hz, Bz), 7.64–7.17 (40H, m aromatic),
159.3, 138.4, 135.7, 135.7, 129.8, 129.6, 129.6, 129.0, 128.4, 128.3,
128.3, 128.2, 128.2, 128.1, 127.9, 127.8, 127.8, 127.7, 127.7, 127.6,
127.5, 125.2, 113.7, 102.1, 101.0, 97.4, 84.4, 82.1, 82.0, 77.7, 77.2,
75.6, 74.8, 74.7, 74.7, 74.5, 74.4, 74.1, 73.9, 72.9, 70.9, 70.7, 69.8,
68.3, 62.8, 61.4, 55.2, 52.4, 37.7, 29.8, 27.8, 26.7; HRMS (positive
7.04 (2H, d, J¼8.8 Hz, MPM), 6.81 (2H, 00d, J¼8.8 Hz, MPM), 5.30
0
00 00
00 00
(1H, dd, J4 ,3 ¼9.5 Hz, J4 ,5 ¼10.2 Hz, H-4 ), 5.20 (1H, s, H-1 ), 5.10
(1H, s, H-20), 4.98 (1H, s, H-50), 4.91 (1H, d, Jgem¼10.8 Hz, PhCH2),
4.91 (1H, d, Jgem¼10.2 Hz, PhCH2), 4.91 (1H, d, Jgem¼10.8 Hz,
PhCH2), 4.79 (1H, d, Jgem¼11.5 Hz, PhCH2), 4.77 (1H,
d, Jgem¼10.2 Hz, PhCH2), 4.74 (1H, d, Jgem¼12.2 Hz, PhCH2), 4.73
mode) found: m/z 1590.6341 [MþNa]þ, calcd for C90H97N3O20
-
00
00 00
SiNa: 1590.6332.
(1H, d, Jgem¼10.8 Hz, PhCH2), 4.72 (1H, d, J1 ,2 ¼4.0 Hz, H-1 ),
4.68 (1H, d, Jgem¼10.8 Hz, PhCH2), 4.56 (1H, d, Jgem¼11.5 Hz,
PhCH2), 4.50 (1H, d, Jgem¼12.2 Hz, PhCH2), 4.44 (1H, d,
J1,2¼7.4 Hz, H-1), 4.16 (1H, s, H-30), 4.03 (1H, s, H-40), 4.03 (1H,
dd, J6a,6b¼11.5 Hz, J6a,5¼1.3 Hz, H-6a), 4.01 (1H, d, Jgem¼10.2 Hz,
PhCH2), 3.92 (1H, d, Jgem¼10.2 Hz, PhCH2), 3.86 (1H, dd,
J6b,6a¼11.5 Hz, J6b,5¼4.7 Hz, H-6b), 3.79–3.77 (4H, 0m0 , H-500, OCH3),
3.26. Methyl [2-O-azido-6-O-tert-butyldiphenylsilyl-2-O-
deoxy-4-O-levulinyl-3-O-(4-methoxybenzyl)-a-D-
glucopyranosyl]-(1/4)-(2-O-benzoyl-3-O-benzyl-L-
idopyranosyl)uronate (31)
00
00
00 00
3.71 (1H, dd, J6a ,6b ¼10.2 Hz, J6a ,5 ¼004.0 Hz, H-6a ), 3.67 (1H, dd,
00
00
00 00
J6b ,6a ¼10.2 Hz, J6b ,5 ¼2.7 Hz, H-6b ), 3.61–3.56 (4H, m, H-3, H-
To a solution of compound 26 (19.9 mg, 17.1
dine (1 ml) was added HF$pyridine (44.4 l, 1.71 mmol) at room
mmol) in pyri-
4, H-5, H-300), 3.42 (1H, dd, J2,1¼7.4 Hz, J2,3¼8.1 Hz, H-2), 3.37 (3H, s,
00
00 00
00 00
m
OCH3), 3.30 (1H, dd, J2 ,1 ¼4.0 Hz, J2 ,3 ¼9.5 Hz, H-2 ), 2.64–2.61
temperature. After being stirred for 2 h, the reaction mixture
was poured into AcOEt. The resulting mixture was washed with
water and brine, dried over Na2SO4, filtered, and concentrated
in vacuo. Flash chromatography (silica gel: 5 g, toluene/
EtOAc¼10:1/3:1) afforded compound 31 as a colorless oil.
(2H,
CH3C(]O)C2H4C(]O)–), 2.16 (3H, s, CH3C(]O)C2H4C(]O)–), 0.99
(9H, s, C(CH3)3); 13C NMR (150 MHz, CDCl3)
206.0, 170.7, 159.2,
m,
CH3C(]O)C2H4C(]O)–),
2.41–2.35
(2H,
m,
d
138.0, 137.3, 135.7, 135.7, 129.9, 129.6, 129.5, 128.5, 128.5, 128.5,
128.4, 128.3, 128.3, 128.3, 128.2, 128.1, 127.9, 127.8, 127.8, 127.7,
127.6, 127.6, 127.5, 127.4, 113.6, 102.3, 99.2, 98.8, 84.6, 82.2, 78.0,
77.5, 75.7, 75.2, 74.9, 74.9, 74.1, 72.4, 72.3, 72.3, 71.0, 70.7, 69.7, 67.8,
67.3, 67.1, 63.3, 61.5, 55.2, 51.8, 37.7, 29.8, 27.8, 26.6; HRMS (positive
mode) found: m/z 1590.6357 [MþNa]þ, calcd for C90H97N3O20SiNa:
1590.6332.
Yield 13.1 mg (73%,
a
/
b
¼5:3). 1H NMR (600 MHz, CDCl3)
d for
a
-anomer 8.18 (2H, d, J¼7.4 Hz, Bz), 7.65–7.17 (18H, m, aro-
matic), 7.04 (2H, d, J¼8.8 Hz, MPM), 6.82 (2H, d, J¼8.8 Hz,
MPM), 5.49 (1H, d, J1,1-OH¼8.8 Hz, H-1), 5.05 (1H, d, J2,3¼2.7 Hz,
H-2), 4.89 (1H, d, J5,4¼2.7 Hz, H-5), 4.87 (1H, d, Jgem¼11.5 Hz,
PhCH2), 4.77 (1H, d, Jgem¼11.5 Hz, PhCH2), 4.68 (1H, d,
0
0
0
J1 ,2 ¼3.4 Hz, H-1 ), 4.34 (1H, dd, J3,2¼2.7 Hz, J3,4¼3.4 Hz, H-3),
4.09 (1H, d, J1-OH,1¼8.8 Hz, 1-OH), 4.01 (1H, dd, J4,3¼3.4 Hz,
J4,5¼2.7 Hz, H-4), 3.96 (1H, d, Jgem¼10.8 Hz, PhCH2), 3.83 (1H, d,
Jgem¼10.8 Hz, PhCH2), 3.77–3.75 (4H, m, H-6a0, OCH3), 3.72–3.68
(2H, m, H-50, H-6b0), 3.500 (3H, s, OCH3), 3.29 (1H, dd,
3.28. Benzyl (2-O-azido-6-O-tert-butyldiphenylsilyl-2-O-
deoxy-3-O-(4-methoxybenzyl)-
(methyl 2-O-benzoyl-3-O-benzyl-
(1/6)-2,3,4-tetra-O-benzyl- -glucopyranoside
a
-D
-glucopyranosyl)-(1/4)-
b-D
-glucopyranosyluronate)-
b-D
0
0
0
0
J2 ,1 ¼3.4 Hz, J2 ,3 ¼7.4 Hz, H-2 ), 2.66–2.59 (2H, m, CH3C(]O)-
C2H4C(]O)–), 2.42–2.31 (2H, m, CH3C(]O)C2H4C(]O)–), 2.16
(3H, s, CH3C(]O)C2H4C(]O)–), 1.00 (9H, s, C(CH3)3); 13C NMR
Compound 30 (649 mg, 0.413 mmol) was dissolved in pyridine/
AcOH (3:2, 10 ml) and hydrazine monohydrate (30.2 l, 0.620 mmol)
m
was added at room temperature. After 3 h, the reactionwas quenched
by addition of acetone and the mixture was diluted with AcOEt. The
organic layer was washed with 1 M HCl aq, satd NaHCO3, aq, and
brine, dried over Na2SO4, filtered, and concentrated in vacuo. Flash
chromatography (silica gel: 30 g, toluene/EtOAc¼20:1/10:1)
afforded benzyl (2-O-azido-6-O-tert-butyldiphenylsilyl-2-O-deoxy-
(150 MHz, CDCl3)
d for b-anomer 206.0, 170.7, 165.8, 159.2,
135.7, 135.7, 133.2, 130.0, 129.7, 129.6, 129.5, 128.6, 128.5, 128.5,
128.3, 127.5, 127.4, 127.4, 113.6, 99.2, 93.6, 77.9, 74.7, 74.0, 73.6,
72.5, 71.2, 69.7, 68.2, 67.4, 63.2, 61.4, 55.2, 52.1, 37.7, 29.8, 27.8,
26.6; HRMS (positive mode) found: m/z 1068.3912 [MþNa]þ,
calcd for C56H63N3O15SiNa: 1068.3926.
3-O-(4-methoxybenzyl)-a-D-glucopyranosyl)-(1/4)-(methyl 2-O-

A. Saito et al. / Tetrahedron 66 (2010) 3951–3962
3961
benzoyl-3-O-benzyl-
O-benzyl-
-glucopyranosideasawhitesolid. Yield540 mg(89%).1H
NMR (600 MHz, CDCl3)
b
-
D
-glucopyranosyluronate)-(1/6)-2,3,4-tetra-
3.30. Benzyl (2-O-azido-2-O-deoxy-3-O-(4-methoxybenzyl)-4-
O-methyl- -glucopyranosyl)-(1/4)-(methyl 2-O-benzoyl-3-
O-benzyl- -glucopyranosyluronate)-(1/6)-2,3,4-tetra-O-
benzyl- -glucopyranoside (35)
b-D
a-D
b-D
b-D
d
7.96 (2H, d, J¼8.1 Hz, Bz), 7.69–7.13 (40H,
m, aromatic), 6.91 (2H, d, J¼8.1 Hz, MPM), 5.40–5.38 (2H, m, H-100,
H-20), 4.88 and 4.79 (each 1H, d, Jgem¼10.8 Hz, PhCH2), 4.84 and
4.80 (each 1H, d, Jgem¼10.8 Hz, PhCH2), 4.79 and 4.64 (each 1H, d,
Jgem¼10.8 Hz, PhCH2), 4.72 and 4.71 (each 1H, d, Jgem¼12.2 Hz,
PhCH2), 4.68 and 4.45 (each 1H, d, Jgem¼11.5 Hz, PhCH2), 4.67 (1H, d,
To a solution of compound 34 (19.9 mg, 13.4 mmol) in pyridine
(4 ml) was added HF$pyridine (174 l, 6.70 mmol) at room tem-
m
perature. The mixture was stirred for 2 days. The volatiles were
removed in vacuo. Flash chromatography (silica gel: 5 g, toluene/
EtOAc¼10:1/4:1) afforded compound 35 as a colorless oil. Yield
0
0
0
J1 ,2 ¼8.1 Hz, H-1 ), 4.66 and 4.41 (each 1H, d, Jgem¼12.2 Hz, PhCH2),
0
0
0
0
4.36 (1H, d, J1,2¼7.4 Hz, H-1), 4.25 (1H, dd, J4 ,5 ¼8.8 Hz, J4 ,3 ¼8.8 Hz,
H-40), 4.11 (1H, d, J6a ,6b ¼10.8 Hz, H-6a ), 4.01 (1H, d, J5 ,4 ¼8.8 Hz,
H-50), 3.94–3.90 (2H, m, H-6a, H-30), 3.79–3.72 (6H, m, H-6b, H-300,
H-400, OCH3), 3.60–3.53 (5H, m, H-3, H-6b00, OCH3), 3.47–3.40 (3H, m,
H-2, H-5, H-500), 3.35 (1H, dd, J4,5¼9.5 Hz, J4,3¼9.5 Hz, H-4), 3.22 (1H,
15.9 mg (95%). 1H NMR (600 MHz, CDCl3)
d
7.97 (2H, d, J¼6.8 Hz,
00
00
00
0
0
Bz), 7.47–7.13 (30H, m, ar0o0 matic), 6.90 (2H, d, J¼8.8 Hz, MPM), 5.41
00 00
0
0
0
0
(1H, d, J1 ,2 ¼3.3 Hz, H-1 ), 5.41 (1H, dd, J2 ,1 ¼7.4 Hz, J2 ,3 ¼8.8 Hz,
H-20), 4.88 and 4.86 (each 1H, d, Jgem¼10.8 Hz, PhCH2), 4.82 and
4.69 (each 1H, d, Jgem¼10.2 Hz, PhCH2), 4.77 and 4.75 (each 1H, d,
00
00 00
00 00
00
dd, J2 ,3 ¼9.5 Hz, J2 ,1 ¼3.3 Hz, H-2 ), 2.78 (1H, d, JOH,4 ¼1.3 Hz, OH),
1.05 (9H, s, C(CH3)3); 13C NMR (150 MHz, CDCl3)
d
168.3, 164.8, 159.3,
Jgem¼9.5 Hz, PhCH2), 4.73 (1H, d, J1 ,2 ¼7.4 Hz, H-1 ), 4.70 and 4.65
(each 1H, d, Jgem¼10.8 Hz, PhCH2), 4.70 and 4.45 (each 1H, d,
Jgem¼10.8 Hz, PhCH2), 4.69 and 4.42 (each 1H, d, Jgem¼10.2 Hz,
0
0
0
137.8, 137.2, 135.6, 129.9, 129.9, 129.8, 129.6, 128.4, 128.3, 128.3, 128.3,
128.2, 128.1, 127.9, 127.9, 127.8, 127.7, 127.7, 127.6, 113.9, 102.1, 101.1,
97.5, 84.4, 82.2, 82.0, 78.8, 77.7, 75.6, 74.8, 74.8, 74.7, 74.5, 74.4, 74.3,
73.1, 73.0, 70.9, 70.7, 68.2, 64.0, 62.5, 55.2, 52.5, 26.8; HRMS (positive
mode) found: m/z 1492.5978 [MþNa]þ, calcd for C85H91N3O18SiNa:
1492.5965.
0
0
PhCH2), 4.37 (1H, d, J1,2¼8.1 Hz, H-1), 4.31 (1H, dd, J4 ,3 ¼8.1 Hz,
0
0
0
J4 ,5 ¼8.8 Hz, H-4 ), 4.12 (1H, dd, J6a,5¼1.3 Hz, J6a,6b¼10.8 Hz, H-6a),
4.06 (1H, d, J5 ,4 ¼8.8 Hz, H-50), 3.94 00(1H, dd, J3 ,2 ¼8.8 Hz,
0
0
0
0
0
00
0
0
J3 ,4 ¼8.1 Hz, H-3 ), 3.87–3.75 (8H, m, H-3 , H-6a , OCH3ꢂ2), 3.69
(1H, dd, J6b ,5 ¼3.4 Hz, J6b ,6a ¼11.5 Hz, H-6b00), 3.60–3.54 (5H, m, H-
3, H-6b, OCH3), 3.45–3.38 (3H, m, H-2, H-5, H-500), 3.34 (1H, dd,
J4,3¼8.8 Hz, J4,5¼10.2 Hz, H-4), 3.24–3.21 (2H, m, H-200, H-400); 13C
00 00
00
00
3.29. Benzyl [2-O-azido-6-O-tert-butyldiphenylsilyl-2-O-
deoxy-3-O-(4-methoxybenzyl)-4-O-methyl-
a-D-
glucopyranosyl]-(1/4)-(methyl 2-O-benzoyl-3-O-benzyl-
b
-D
-
NMR (150 MHz, CDCl3) d 168.6, 164.8, 138.4, 138.2, 133.2, 129.8,
glucopyranosyluronate)-(1/6)-2,3,4-tetra-O-benzyl-
glucopyranoside (34)
b
-
D
-
129.6, 128.4, 128.3, 128.3, 128.3, 128.1, 127.9, 127.8,127.8, 127.7, 127.7,
127.6, 113.8, 102.1, 101.0, 97.5, 84.4, 82.2, 82.0, 80.0, 79.3, 77.7, 75.6,
75.0, 75.0, 74.7, 74.6, 74.4, 74.4, 73.3, 72.1, 70.7, 68.3, 63.0, 61.2, 60.8,
55.2, 52.8; HRMS (positive mode) found: m/z 1172.4349 [MþNa]þ,
calcd for C70H75N3O18Na: 1172.4344.
To a solution of benzyl (2-O-azido-6-O-tert-butyldiphenylsilyl-
2-O-deoxy-3-O-(4-methoxybenzyl)- -glucopyranosyl)-(1/4)-
(methyl 2-O-benzoyl-3-O-benzyl- -glucopyranosyluronate)-
(1/6)-2,3,4-tetra-O-benzyl- -glucopyranoside (11.0 mg, 7.48 mol)
in anhydrous DMF (2 ml) were added MeI (0.90 l, 15 mol) and
a-D
b-D
b-D
m
3.31. 2-Deoxy-4-O-methyl-2-sulfoamino-
(1/4)-( -glucopyranosyluronic acid)-(1/6)-
glucopyranose disodium salt (38)
a-D-glucopyranosyl-
m
m
b-D
D-
MS4AP (200 mg) at room temperature under Ar and the mix-
ture was stirred for 2 h. After cooling to ꢁ20 ꢀC, lithium hex-
amethyldisilazide (LHMDS) in THF (7.0
ml, 1.6 M) was added at
To a solution of compound 35 (70.6 mg, 60.9
anol/THF (1:1, 1.6 ml) was added 1 M NaOH aq (400
m
mol) in meth-
l) at room
the same temperature. The reaction mixture was further stirred
and gradually warmed to 0 ꢀC. After 4 h, the reaction was
quenched by the addition of methanol and the reaction mixture
was filtered through a Celite pad. The filtrate was washed with
10% Na2S2O3 aq and brine, dried over Na2SO4, filtered, and
concentrated in vacuo. Flash chromatography (silica gel: 5 g,
toluene/EtOAc¼30:1/10:1) afforded compound 34 as a white
m
temperature. After 24 h, the reaction was quenched by addition of
Dowex 50W (Hþ). After removal of insoluble materials by filtra-
tion, the filtrate was concentrated in vacuo. To a solution of the
residue in methanol/THF (1:1, 3.2 ml) was added 0.1 M NaOH aq
(974
temperature. After 2 days, the reaction was quenched by addition
of 0.1 M HCl aq (974 l). After the volatiles were removed in
ml) and 1 M PMe3 in THF (487 ml, 0.487 mmol) at room
solid. Yield 9.44 mg (85%). 1H NMR (600 MHz, CDCl3)
d
7.97 (2H,
m
d, J¼6.8 Hz, Bz), 7.70–7.12 (40H, m, aromatic), 6.91 (2H, d,
vacuo, the residue was dissolved in H2O (10 ml). SO3$pyridine
(970 mg, 6.09 mmol) was added. The pH of the reaction mixture
was maintained at 9.5 by the addition of 5 M NaOH aq during the
reaction. After 5 h, the volatiles were removed in vacuo. The
residue was then suspended in MeOH. Insoluble materials were
removed by filtration and the filtrate was concentrated in vacuo.
Reversed phase chromatography (ODS: 6 g, H2O/MeOH¼8:1/
0:1) afforded compound 37. Obtained 37 was dissolved in H2O/
MeOH/AcOH (5:5:1, 16 ml). Pd/C (10%, 51.2 mg) was added to the
mixture. The reaction mixture was stirred for 6 days at room
temperature under H2 (7 kg/cm2). After filtration by membrane
filter, the filtrate was concentrated in vacuo. Gel filtration
0
0
0
0
0
J¼8.8 Hz, MPM), 5.42 (1H, dd, J2 ,1 ¼8.1 Hz, J2 ,3 ¼8.1 Hz, H-2 ),
00
00 00
5.37 (1H, d, J1 ,2 ¼4.0 Hz, H-1 ), 4.87 and 4.81 (each 1H, d,
Jgem¼10.8 Hz, PhCH2), 4.85 and 4.69 (each 1H, d, Jgem¼10.2 Hz,
PhCH2), 4.82 and 4.78 (each 1H, d, Jgem¼13.6 Hz, PhCH2), 4.79
and 4.39 (each0 1H, d, Jgem¼12.2 Hz, PhCH2), 4.70 (1H, d,
0
0
J1 ,2 ¼8.1 Hz, H-1 ), 4.68 and 4.63 (each 1H, d, Jgem¼10.2 Hz,
PhCH2), 4.67 and 4.42 (each 1H, d, Jgem¼10.8 Hz, PhCH2), 4.34
0
0
0
0
(1H, d, J1,2¼7.4 Hz, H-1), 4.20 (1H, dd, J4 ,3 ¼8.8 Hz, J4 ,5 ¼8.8 Hz,
H-40), 4.09 (1H, d, J6a,6b¼10.8 Hz, H-6a), 4.01 (1H, d, J5 ,4 ¼8.8 Hz,
H-50), 3.94–3.89 (2H, m, H-30, H-6a00), 3.81–3.78 (5H, m, H-300,
H-6b00, OCH3), 3.62–3.50 (9H, m, H-3, H-6b, H-400, OCH3ꢂ2),
3.41–3.36 (2H, m, H-2, H-5), 3.32–3.28 (2H, m, H-4, H-500), 3.25
0
0
(Sephadex G-25 fine:
38 as a white solid. Yield 4.52 mg (11%,
4
1.5ꢂ1000 mm, H2O) afforded compound
(1H, dd, J2 ,1 ¼4.0 Hz, J2 ,3 ¼10.8 Hz, H-2 ), 1.02 (9H, s, C(CH3)3);
a/b
¼1:2, four steps). 1H
00
00 00
00 00
13C NMR (150 MHz, CDCl3)
d
168.3, 164.8, 159.4, 138.2, 137.2,
NMR (600 MHz, D2O)
d
for
b
-anomer 5.40 (1H, d, J1 ,2 ¼3.4 Hz, H-
00 00
0
100), 4.45 (1H, d, J1,2¼8.1 Hz, H-1), 4.39 (1H, d, J1 ,2 ¼8.1 Hz, H-1 ),
0
0
137.2, 135.8, 135.5, 130.0, 129.9, 129.6, 129.6, 128.4, 128.3, 128.3,
128.2, 128.1, 127.9, 127.8, 127.8, 127.8, 127.7, 127.7, 127.6, 127.6,
127.5, 113.9, 102.0, 101.0, 97.6, 84.4, 82.2, 82.0, 79.6, 79.2, 77.7,
75.6, 75.2, 74.7, 74.6, 74.5, 74.4, 74.2, 74.2, 73.0, 72.3, 70.7, 68.3,
63.1, 61.6, 60.7, 55.2, 52.5, 26.8; HRMS (positive mode) found:
m/z 1506.6133 [MþNa]þ, calcd for C86H93N3O18SiNa: 1506.6121.
00
00
3.97 (1H, d, J6a,6b¼11.5 Hz, H-6a), 3.92 (1H, d, J6a ,6b ¼11.5 Hz, H-
6a00), 3.82 (1H, d, J5 ,4 ¼8.8 Hz, H-5 ), 3.67–3.60 (6H, m, H-5, H-6b,
0
0
0
H-30, H-40, H-500, H-6b00), 3.48 (1H, dd, J3 ,2 ¼10.2 Hz, J3 ,4 ¼9.5 Hz,
H-300), 3.41 (1H, dd, J4,3¼8.8 Hz, J4,5¼8.8 Hz, H-4), 3.36 (3H, s,
OCH3), 3.28 (1H, dd, J3,2¼8.8 Hz, J3,4¼8.8 Hz, H-3), 3.22 (1H, dd,
00 00
00 00

3962
A. Saito et al. / Tetrahedron 66 (2010) 3951–3962
J2 ,1 ¼8.1 Hz, J2 ,3 ¼008.1 Hz, H-20), 3.13 (1H, dd, J4 ,3 ¼9.5 Hz,
Kulkarni, S. S.; Wen, Y. S.; Hung, S. C. J. Am. Chem. Soc. 2004, 126, 476–477; (h)
0
0
0
0
00 00
Orgueira, H. A.; Bartolozzi, A.; Schell, P.; Litjens, R. E.; Palmacci, E. R.; Seeberger,
P. H. Chem.dEur. J. 2003, 9, 140–169; (i) de Paz, J. L.; Ojeda, R.; Reichadt; Martı´n-
Lomas, M. Eur. J. Org. Chem. 2003, 3308–3324; (j) Kovensky, J.; Mallet, J. M.;
Esnault, J.; Driguez, P. A.; Sizun, P.; He´rault, J. P.; Herbert, J. M.; Petitou, M.;
Sinay¨, P. Eur. J. Org. Chem. 2002, 3595–3603; (k) de Paz, J. L.; Angulo, J.; Lassaletta,
J. M.; Nieto, P. M.; Redondo-Horcajo, M.; Lozano, R. M.; Gimenez-Gallego, G.;
Martin-Lomas, M. ChemBioChem 2001, 2, 673–685 and references cited therein.
5. For recent articles on HP/HS oligosaccharide library, see: (a) Hecht, M. L.;
Rosental, B.; Horlacher, T.; Hershkovitz, O.; de Paz, J. L.; Noti, C.; Schauer, S.;
Porgador, A.; Seeberger, P. J. Proteome Res. 2009, 8, 712–720; (b) Herczeg, M.;
La´za´r, L.; Borba´s, A.; Lipta´k, A.; Antus, S. Org. Lett. 2009, 11, 2619–2622; (c)
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Andrian, U. H.; Seeberger, P. J. ACS Chem. Biol. 2007, 2, 735–744; (e) Lu, L.-D.;
Shie, C.-R.; Kulkarni, S. S.; Pan, G.-R.; Lu, X.-A.; Hung, S.-C. Org. Lett. 2006, 8,
5995–5998; (f) Fan, R.-H.; Achkar, J.; Herna´ndes-Torres, J. M.; Wei, A. Org. Lett.
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6. For our previous studies, see: (a) Wakao, M.; Saito, A.; Ohishi, K.; Kishimoto, Y.;
Nishimura, T.; Sobel, M.; Suda, Y. Bioorg. Med. Chem. Lett. 2008, 18, 2499–2504;
(b) Suda, Y.; Arano, A.; Fukui, Y.; Koshida, S.; Wakao, M.; Nishimura, T.; Kusu-
moto, S.; Sobel, M. Bioconjugate Chem. 2006, 17, 1125–1135; (c) Koshida, S.;
Suda, Y.; Sobel, M.; Kusumoto, S. Tetrahedron Lett. 2001, 42, 1289–1292; (d)
Koshida, S.; Suda, Y.; Fukui, Y.; Ormsby, J.; Sobel, M.; Kusumoto, S. Tetrahedron
Lett. 1999, 40, 5725–5728; (e) Suda, Y.; Bird, K.; Shiyama, T.; Koshida, S.;
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1053–1056.
00 00
00 00
00 00
J4 ,5 ¼10.2 Hz, H-4 ), 3.07 (1H, dd, J2 ,1 ¼3.4 Hz, J2 ,3 ¼10.2 Hz, H-
200), 3.60 (1H, dd, J2,1¼8.1 Hz, J2,3¼8.8 Hz, H-2); 13C NMR (150 MHz,
D2O)
d 172.9, 102.6, 97.5, 95.8, 78.7, 76.4, 75.7, 75.5, 74.7, 73.9,
72.5, 70.8, 70.6, 70.2, 69.3, 68.9, 68.7, 59.6, 57.9, HRMS (negative
mode) found: m/z 632.1133 [MꢁNa]ꢁ, calcd for C19H31NO19SNa:
632.1114.
Acknowledgements
The presentwork was financiallysupported inpartbygrants from
Japan Science and Technology Agency (Evolutionally-venture pro-
gram V07-05 to Y.S., CREST to Y.S.), and the Japan Ministry of Health,
Labour and Welfare (MHLW) (Nanomedicine program to Y.S.), and
the National Institutes of Health, USA (RO1 HL079182 to M.S.).
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