A stereoselective 1,2-cis glycosylation toward the synthesis of a novel N-linked glycan from the Gram-negative bacterium, Campylobacter jejuni

Article abstract of DOI:10.1016/j.carres.2006.03.011

It has been shown that certain prokaryotes, such as Campylobacter jejuni, have asparagine (Asn)-linked glycoproteins. However, the structures of their glycans are distinct from those of eukaryotic origin. They consist of a bacillosamine residue linked to

Full text of DOI:10.1016/j.carres.2006.03.011

Carbohydrate Research 341 (2006) 1557–1573
A stereoselective 1,2-cis glycosylation toward the synthesis of a
novel N-linked glycan from the Gram-negative bacterium,
Campylobacter jejuni
Akihiro Ishiwata,a,b Soichi Ohtaa and Yukishige Itoa,b,
*
aRIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
bCREST, JST, Kawaguchi, Saitama 332-0012, Japan
Received 30 January 2006; received in revised form 3 March 2006; accepted 9 March 2006
Available online 17 April 2006
Abstract—It has been shown that certain prokaryotes, such as Campylobacter jejuni, have asparagine (Asn)-linked glycoproteins.
However, the structures of their glycans are distinct from those of eukaryotic origin. They consist of a bacillosamine residue linked
to Asn, an a-(1!4)-GalpNAc repeat, and a branching b-Glcp residue. In this paper, we describe a strategy for the stereoselective
construction of the a-(1!4)-GalpNAc repeat of a C. jejuni N-glycan, utilizing a pentafluoropropionyl (PFP) group as a temporary
protective group of the C-4 OH group of the GalpN donor. The strategy was applied to the synthesis of the hexasaccharide a-Galp-
NAc-(1!4)-a-GalpNAc-(1!4)-[b-Glcp-(1!3)]-a-GalpNAc(1!4)-a-GalpNAc-(1!4)-GalpNAc.
ꢀ 2006 Elsevier Ltd. All rights reserved.
Keywords: Glycoprotein; Campylobacter jejuni; Stereoselective synthesis; 1,2-cis Glycosylation; Protecting group
1. Introduction
[b-Glcp-(1!3)]-a-GalpNAc(1!4)-a-GalpNAc-(1!4)-a-
GalpNAc-(1!3)-b-Bacp-heptasaccharide (Fig. 1), where
Bac is bacillosamine (2,4-diacetamido-2,4,6-trideoxy-
D-glucopyranose). This N-linked glycan structure is
distinct from eukaryotic glycoprotein glycans, which
consist of a core pentasaccharide (Man3GlcNAc2) deco-
rated with various sugar residues. The biosynthetic
pathway of the C. jejuni N-glycan is, however, quite sim-
ilar to that of eukaryotes. It is believed that a preassem-
bled Und-P-P-heptasaccharide (Und = undecaprenyl)
flips from the cytoplasm to the periplasm, where transfer
of the heptasaccharide to the Asn moiety takes place
under the control of OST.6 The presence of this glycan
on the surface of C. jejuni was shown to play a key role
in enteric adhesion to host cells,7 and this adhesion
constitutes the first step of virulence.8 A relationship
N-Glycosylation is a well-conserved eukaryotic protein
modification.1 The tetradecasaccharide Glc3Man9Glc-
NAc2 is transferred to Asn residues in Asn-Xaa-Thr/
Ser motifs via the action of oligosaccharyltransferase
(OST) in the endoplasmic reticulum (ER) and further
modification takes place in the Golgi apparatus.2 Con-
trary to previous belief, certain prokaryotes are able to
produce glycosylated proteins.3 A major non-flagellin
antigenic glycoprotein designated PEB3 or Cj0289c
has recently been identified in the pathogenic Gram-neg-
ative bacterium, Campylobacter jejuni.4 This glycopro-
tein has multiple glycosylation sites with novel glycans
at Asn residues in the consensus sequence Asn-Xaa-
Thr/Ser, as is the case in eukaryotes.5 The glycan is
composed of a-GalpNAc-(1!4)-a-GalpNAc-(1!4)-
´
between C. jejuni infection and Guillian Barre syndrome
(GBS) has since been reported.9 Very recently, the
in vitro assembly of the Und-P-P-linked glycoconjugate
from C. jejuni has been reported.10 Here, we report a
strategy for the stereoselective synthesis of the repeating
*
Corresponding author. Fax: +81 48 462 4680; e-mail: yukito@
riken.jp
0008-6215/$ - see front matter ꢀ 2006 Elsevier Ltd. All rights reserved.
doi:10.1016/j.carres.2006.03.011

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A. Ishiwata et al. / Carbohydrate Research 341 (2006) 1557–1573
GalNAcα1→4GalNAcα1→4
GalNAcα1→4GalNAcα1→4GalNAcα1→3Bacβ1→ Asn-X-Ser/Thr
Glcβ1→3
(Glc1GalNAc5)
OH
HO
HO
O
AcNH
HO
O
AcNH
OH
O
OH
OH
OH
O
OAc
O
O
O
OBn
O
HO
HO
PFPO
BnO
O
AcO
AcO
SMe
OH
AcNH
HO
O
F
OAc
N3
AcNH
O
OH
2
1
O
PFP : CF3CF2CO
O
HO
AcNH
O
Me
O
H
AcNH
N
O
AcNH
O
NH
Figure 1. Structure of the C. jejuni N-linked glycan.
a-GalpNAc-(1!4)-a-GalpNAc motif, which was then
applied to synthesis of the branched hexasaccharide
Glc1GalNAc5.
propionyl (PFP) protected GalpN donor, such as 1,
while the peracetylated thioglycoside 2 was adopted as
the Glcp donor.
We recently reported the use of PFP groups as a
hydroxyl-protecting group for the stepwise synthesis of
oligosaccharides.15 Removal of the PFP group can be
conducted under extremely mild basic conditions, such
as pyridine–EtOH or DABCO–EtOH, with complete
retention of an acetyl group. It proceeds quantitatively
and the byproduct, ethyl pentafluoropropionate, is vol-
atile (bp 75–76 ꢁC). Therefore, the product can be used
for subsequent transformations immediately after evap-
oration. In addition to the ease of removal, its strongly
electron withdrawing nature attracted our attention.
Based on electrostatic considerations,16 at the outset
we expected that the PFP ester at C-4 would enhance
the intrinsic a-selectivity of the 2-azido glycosyl donor
to neutralize the strong dipole moment caused by a
PFP group in the axial orientation, thus favoring the
formation of an a-glycoside (Fig. 2).
2. Results and discussion
Construction of a-GalpNAc glycosides, which consti-
tute the linkage region of Ser/Thr-linked glycoproteins,
has been examined in depth.11,12 Conventionally, 2-azi-
do-2-deoxy-Galp derivatives,13 which are obtainable
from galactose, have been used for this purpose. More
recently, Kiso and co-workers14 reported a highly effi-
cient approach, which allows for the nearly exclusive
formation of a-GalpN glycosides. In this case, donors
protected with a 4,6-O-di-tert-butylsilylene group were
employed. Strikingly, these donors gave a-GalpN prod-
ucts, even when the C-2 nitrogen was protected with 1,2-
trans directing group such as phthaloyl, trichloroethoxy-
carbonyl or acetyl. However, this method may not be
optimally suitable for our target because it consists of
(1!4)-linked GalpNAc repeats and selective liberation
of the C-4 hydroxyl group is required after each glyco-
sylation. Instead, we set out to use a 4-O-pentafluoro-
Scheme 1 shows the preparation of the synthetic
building blocks. tert-Butyldiphenylsilyl 2-azido-4,6-O-
benzylidene-2-deoxy-b-D-galactopyranoside (3a)17 was
used as the common precursor for the monosaccharide

A. Ishiwata et al. / Carbohydrate Research 341 (2006) 1557–1573
1559
OPFP
OBn
O
O
O
OPFP
OBn
BnO
BnO
O
OPFP
OBn
HO
N3
activation
O
O
β-glycoside
BnO
BnO
F
OPFP
OBn
O
N3
HO
N3
O
N3
O
O
α-glycoside
Figure 2. Stereoelectronic effect of electron-withdrawing group at the C-4 position.
OBn
OBn
O
R2O
BnO
PFPO
BnO
b) c) d)
e)
OPFP
BnO
O
3b
OR1
F
N3
N3
N3
O
OBn
OBn
1
O
R1
TBPS
TBPS PFP
H
H
R2
H
Ph
4
a
b
c
d
O
BnO
OTBPS
O
O
N3
f)
O
PFP
Ac
RO
OTBPS
N3
5
3
a
b
R
H
Bn
a)
OR3
O
OBn
PFPO
OAc
R2O
O
OAc
O
g) b) c) d)
h)
O
O
AcO
AcO
AcO
AcO
OR1
O
F
3a
N3
R3
N3
OAc
OAc
R1
TBPS
TBPS
R2
H
7
6
a
b
c
d
PhCH
Bn
TBPS PFP Bn
PFP Bn
H
Scheme 1. Synthesis of mono- and disaccharide blocks. Reagents and conditions: (a) BnBr, Ag2O, 88%; (b) NaBH3CN, HCl, 97% (4a), 90% (6b); (c)
PFP2O, pyridine, quant. (4b), 85% (6c); (d) HF, THF, 94% (4c), 99% (6d); (e) DAST, 91% (1), 94% (7); (f) 4a, Cp2HfCl2, AgClO4, CHCl3, 92%; (g) 2,
NIS, TfOH, CH2Cl2–toluene, 77%.
donor 1, acceptor 4a as well as disaccharide donor 7. It
was first protected with a benzyl group18 to give 3b and
reductive ring-opening of benzylidene acetal19 gave 4a.
For synthesis of the glycosyl donor 1, compound 4a
was treated with PFP2O in the presence of pyridine to
give PFP ester 4b. Desilylation with HF–pyridine com-
plex20 in THF and subsequent fluorination of the result-
ing hemiacetal 4c with DAST21 gave 1 as a mixture of
anomers (a:b = 31:69). Separation by SiO2 column
chromatography gave pure b-isomer 1b, which was used
for the screening of subsequent glycosylation.
on the effect of the activator; the results are summarized
in Table 1. When SnCl2–AgClO4 was used, the reac-
22
tion was extremely slow, presumably reflecting the dis-
armed nature of 1b. A combination of AgX (X = ClO4
or OTf) with Cp2MCl2 (M = Hf, Zr, Ti)23 proved to
be suitable for our purposes, among which AgClO4–
Cp2HfCl2 was most efficient in providing product 5 in
high yield and selectivity. Larger amounts of the
promoter (entry 17) or elevated temperature (entry 15)
resulted in
a slightly increased yield. Although
comparable results were obtained in CHCl3 (entry 8),
CH2Cl2 (entry 1) and toluene (entry 9), Et2O (entry
10) gave lower yield. The stereoselectivity was also
Coupling of the glycosyl acceptor 4a with 1b
(1.2 equiv) was examined, with the primary focus being

1560
A. Ishiwata et al. / Carbohydrate Research 341 (2006) 1557–1573
Table 1. Glycosylation of 4a with 1b
Entrya
Activator
Solvent
Temp
Yield (%)
a/b
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18b
AgClO4 (3.6)/Cp2HfCl2 (1.8)
AgClO4 (3.6)/Cp2ZrCl2 (1.8)
AgClO4 (3.6)/Cp2TiCl2 (1.8)
AgClO4 (3.6)/SnCl2 (1.8)
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CHCl3
Toluene
Et2O
CH3CN
CPME
1,4-Dioxane
CHCl3
rt
rt
rt
rt
rt
rt
rt
rt
rt
rt
rt
rt
85
58
69
4
75
0
93/7
95/5
95/5
86/14
95/5
—
AgOTf (3.6)/Cp2HfCl2 (1.8)
AgSbF6 (3.6)/Cp2HfCl2 (1.8)
AgPF6 (3.6)/Cp2HfCl2 (1.8)
AgClO4 (3.6)/Cp2HfCl2 (1.8)
AgClO4 (3.6)/Cp2HfCl2 (1.8)
AgClO4 (3.6)/Cp2HfCl2 (1.8)
AgClO4 (3.6)/Cp2HfCl2 (1.8)
AgClO4 (3.6)/Cp2HfCl2 (1.8)
AgClO4 (3.6)/Cp2HfCl2 (1.8)
AgClO4 (3.6)/Cp2HfCl2 (1.8)
AgClO4 (3.6)/Cp2HfCl2 (1.8)
AgClO4 (2.6)/Cp2HfCl2 (1.3)
AgClO4 (5.2)/Cp2HfCl2 (2.6)
AgClO4 (3.6)/Cp2HfCl2 (1.8)
0
—
87
81
44
0
0
0
77
90
74
92
87
95/5
94/6
85/15
—
—
—
93/7
94/6
94/6
94/6
94/6
rt
0 ꢁC
60 ꢁC
rt
rt
rt
CHCl3
CHCl3
CHCl3
CHCl3
a All reactions were quenched after 42 h.
b a-Isomer 1a was used instead of b-isomer 1b.
diminished in Et2O. Other coordinating solvents, such
as dioxane (entry 13), cyclopentyl methyl ether (CPME,
entry 12) and acetonitrile (entry 11), were unsuitable for
this reaction. a-Fluoride (1a) was shown to be equally
effective in giving 5 in high yield (entry 18).
contrary to our expectation, glycosylation of 4a with 8
gave the disaccharide 9 in slightly higher selectivity,
albeit with lower yield, when compared with 1 (Scheme
2A, entry 2). In contrast to 1, the selectivity was even
higher in Et2O, although the yield was unacceptable
(entry 4). These results imply that reaction pathways
may be different for 1 and 8, with remote-participation
For comparison, the 4-O-acetylated donor 8, which
was prepared from 4a via 4d, was examined. Somewhat
OBn
RO
1 : R = PFP
OR
O
OH
8 : R = Ac
BnO
BnO
O
BnO
F
N3
N3
N3
O
AgClO4, Cp2HfCl2
OBn
OBn
pyridine/EtOH
OBn
OBn
+
O
O
O
O
OBn
O
BnO
OTBPS
BnO
OTBPS
HO
N3
N3
BnO
OTBPS
N3
5 : R = PFP
9 : R = Ac
10
4a
solvent
CHCl3
CHCl3
Et2O
product
yield (%)
α/β
94/6
96/4
85/15
98/2
donor
5
9
5
9
92
80
44
13
1
8
1
8
Et2O
(A)
Me
O+
OBn
R = Ac
O
O
BnO
RO
BnO
OBn
O+
N3
1/8
5/9
N3
(B)
R = PFP
Scheme 2. (A) Comparison of 4-O-PFP (1) and 4-O-Ac (8) protected donors. (B) Possible reaction pathways.

A. Ishiwata et al. / Carbohydrate Research 341 (2006) 1557–1573
1561
of 4-O-acetyl group24 being the dominant factor in the
latter case (Fig. 2B).
tion conditions (H2, Pd(OH)2, (i-Pr)2NEt, CH3OH). Sub-
sequent acetamide formation and hydrogenolysis of the
nine benzyl groups gave free oligosaccharide 15, which
was confirmed by mass spectrometry (Scheme 4).
Attempts to simultaneously reduce the azides and remove
benzyl groups provided a complex mixture. In CD3OD,
For the construction of repeating GalpNAc sequence,
consecutive PFP deprotection and glycosylation under
the above-described conditions were performed. Depro-
tection of disaccharide 5 proceeded smoothly in the
presence of 20 equiv of pyridine in ethanol to give 10
(Scheme 2).
Glycosylation of disaccharide acceptor 10 with com-
mon donor 1 (2.6 equiv of Cp2HfCl2 and 5.2 equiv of
AgClO4 in CHCl3 at room temperature) gave trisaccha-
ride 11a in good yield (Scheme 3). After repeating two
additional deprotection–glycosylation cycles, pentasac-
charide 11e was obtained in good overall yield and selec-
tivity, via 11b, 11c and 11d.
We then conducted the synthesis of glucose-branched
hexasaccharide. For construction of the branched struc-
ture, a disaccharide donor (b-Glcp-(1!3)-GalpN3) 7
was used as the third component (Scheme 4). The latter
was synthesized from 3a through b-selective glucosyl-
ation with methyl 2,3,4,6-tetra-O-acetyl-1-thio-b-D-
glucopyranoside (2) under NIS–TfOH activation condi-
tions (Scheme 1). Glycosylation of acceptor 10 with
donor 7b was briefly examined as summarized in Table
2. Although a significant reduction in selectivity was
observed, isomer separation could be readily conducted
by silica gel column chromatography and tetrasaccha-
ride 12 was obtained in reasonable yield (Table 2). In
addition, an a-fluoride provided a higher yield with
nearly identical selectivity (Table 2, entry 8). Deprotec-
tion of the PFP group cleanly provided 13 without
affecting the acetyl groups (Scheme 4). Elongation of
two GalpN residues was then carried out to give
glucose-branched hexasaccharide 14c.23
1
the hexasaccharide gave poor H NMR spectra due to
severe peak broadening, even at 50 ꢁC. This was possibly
due to restricted conformer exchange, because of the
extensive intramolecular hydrogen-bonding network of
acetamides as suggested by molecular modeling25
(Fig. 3). According to modeling in water, the conforma-
tion of all the pyranose rings in the heptasaccharide exists
in the chair-form, possibly due to effective disruption of
intramolecular hydrogen bonding. Although D2O was
unable to dissolve 15, a mixture of CD3OD–D2O (1:1)
gave substantially improved 1H NMR spectra.
In conclusion, an examination of glycosylation reac-
tions for the construction of the linear repeating Galp-
NAc-GalpNAc structure of a novel N-linked glycan
from the Gram-negative bacterium C. jejuni was per-
formed. The use of the novel GalpNAc donor (1) having
a PFP ester at position 4 was effective in giving the a-gly-
coside stereoselectively in good yield. Simple repetition
of PFP deprotection and glycosylation afforded the pen-
ta-a-GalpNAc derivative 11e. Synthesis of glucose-
branched hexasaccharide 15 was achieved using donor
7 as a third component. Further studies toward the
synthesis of the complete structure of C. jejuni-derived
N-glycan and its conjugation to peptide are now underway.
3. Experimental
Deprotection of glucose-branched hexasaccharide 14b
was successfully conducted in a stepwise manner. Thus,
methanolysis of the five esters was followed by selective
reduction of the five azides under controlled hydrogena-
3.1. General methods
All reactions sensitive to air and/or moisture were
carried out under nitrogen or argon atmosphere in
b)
a)
a)
b)
b)
10
11a
11b
11d
11c
11e
OBn
RO
BnO
O
n
1
1
2
2
3
R
11
a
N3
PFP
H
O
b
c
BnO
O
N3
PFP
H
OBn
d
e
n
OBn
O
O
PFP
BnO
OTBPS
N3
Scheme 3. Synthesis of linear pentasaccharide. Reagents and conditions: (a) 1b (1.2 equiv) Cp2HfCl2 (2.6 equiv), AgClO4 (5.2 equiv), CHCl3, 92%,
a:b = 94:6 (11a), 80%, a:b = 96:4 (11c), 70%, a:b = 95:5 (1e); (b) pyridine, EtOH, 80 ꢁC, 88 h, 92% (11b), 99% (11d).

1562
A. Ishiwata et al. / Carbohydrate Research 341 (2006) 1557–1573
OBn
OAc
O
RO
O
O
AcO
AcO
OBn
O
PFPO
O
OAc
+
AcO
AcO
AcO
OAc
N3O
O
F
BnO
N3
N3
O
7β
OBn
a) b)
OBn
OH
BnO
O
O
N3
BnO
OTBPS
O
OBn
OBn
N3
O
O
R
PFP
H
BnO
OTBPS
N3
12
13
10
OH
HO
R
O
O
HO
BnO
AcNH
O
N3
HO
O
OBn
n
AcNH
O
OH
OR
O
OH
OAc
OH
O
O
O
O
O
AcO
AcO
HO
HO
O
O
OAc
N3
OH
O
AcNH
HO
O
RO
N3
AcNH
O
O
d)-g)
OBn
c) b) c)
OH
OBn
OH
O
O
O
O
BnO
OTBPS
HO
OTBPS
N3
AcNH
n
R
14
a
15
1
1
2
PFP
H
b
PFP
c
GalNAcα1→4GalNAcα1→4
Glcβ1→3
GalNAcα1→4GalNAcα1→4GalNAc
Scheme 4. Synthesis of glucose-branched hexasaccharide. Reagents and conditions: (a) see Table 2; (b) pyridine, EtOH, 80 ꢁC, 88 h, 92% (13), quant.
(14b); (c) 1b, Cp HfCl , AgClO , CHCl , 60 ꢁC, 84 h 96%, a:b = >95:5 (14a), 88%, a:b = >95:5 (14c); (d) NaOCH , CH OH; (e) H , Pd(OH) , Hunig
¨
2
2
4
3
3
3
2
2
base, CH3OH; (f) Ac2O, CH3OH; (g) Pd(OH)2, H2, CH3OH–CHCl3–H2O, 44% in four steps.
Table 2. Glycosylation of 10 with 7b
Kagaku Co., Ltd). Preparative TLC was performed on
Silica Gel 60 F254, 0.5 mm (E. Merck). Gel filtration
was performed on Sephadex LH-20 (Pharmacia). Opti-
cal rotations were measured with a JASCO DIP 370
polarimeter. 1H NMR spectra were recorded at 400
MHz on a JEOL JNM-AL 400 spectrometer and chem-
ical shifts are referred to internal residual solvent sig-
nals, 7.24 ppm (CDCl3) or 3.30 ppm (CD3OD). 13C
NMR spectra were recorded at 100 MHz on the same
instrument and chemical shifts are referred to internal
CDCl3 (77.0 ppm). MALDI-TOF mass spectra were re-
corded on a SHIMADZU Kompact MALDI AXIMA-
CFR spectrometer with 2,5-dihydroxybenzoic acid as
the matrix. Electrospray ionization mass spectra were
recorded on a JEOL AccuTOF JMS-T700LCK with
Entrya
Activatorb
Temp
Yield (%)
a/b
1
2
3
4
5
6
7
8c
AgClO4/Cp2HfCl2
AgClO/Cp2HfCl2
AgClO4/Cp2ZrCl2
AgClO4/Cp2TiCl2
AgOTf/Cp2HfCl2
AgPF6/Cp2HfCl2
AgBF4/Cp2HfCl2
AgClO4/Cp2HfCl2
rt
50
72
60
23
60
0
80/20
83/17
83/17
85/15
87/13
—
60 ꢁC
60 ꢁC
60 ꢁC
60 ꢁC
60 ꢁC
60 ꢁC
60 ꢁC
0
89
—
78/22
a All reactions were quenched after 42 h.
b AgX (5.2 equiv) and Cp2MCl2 (2.6 equiv) were used.
c a-Isomer 7a was used instead of 7b.
anhydrous solvents. Column chromatography was
performed on Silica Gel 60N, 100–210 mesh (Kanto

A. Ishiwata et al. / Carbohydrate Research 341 (2006) 1557–1573
1563
Figure 3. Results of molecular modeling of Glc1GalNAc5Bac1-NHAc calculated by MacroModel ver 8.1. (a) In gas phase (the rings of two
GalpNAcs are flipped because of stabilization by intramolecular hydrogen bonding). (b) In H2O (all pyranose rings adopt chair-form).
CF3CO2Na as the internal standard. Elemental analyses
were performed with a Fisons EA1108 instrument.
(33.5 mL, 134 mmol) was added portion-wise at 0 ꢁC
under an Ar atmosphere and the mixture was stirred
for 1.5 h at the same temperature. The reaction mixture
was diluted with EtOAc (100 mL) and filtered through
Celite. The filtrate was washed with satd aq NaHCO3
(300 mL) and brine (300 mL). The washed organic layer
was dried over MgSO4 and concentrated in vacuo. The
crude product was purified by silica gel column chromato-
graphy (4:1, hexane/EtOAc) to give 4a as an amorphous
3.2. tert-Butyldiphenylsilyl 2-azido-3-O-benzyl-4,6-O-
benzylidene-2-deoxy-b-D-galactopyranoside (3b)
To a solution of 3a (101 mg, 0.190 mmol) in dry CH2Cl2
(2 mL), Ag2O (66.1 mg, 0.285 mmol) was added at 0 ꢁC
under an Ar atmosphere and the mixture was stirred for
30 min at the same temperature. To the reaction mix-
ture, benzyl bromide (40.0 lL, 0.33 mmol) was added
and the mixture was stirred for 45 h at rt under an Ar
atmosphere. The reaction mixture was filtered through
Celite and concentrated in vacuo. The crude product
was purified by silica gel column chromatography (9:1,
hexane/EtOAc) to give 3b as an amorphous solid
27
1
solid (6.87 g, 97%): ½aꢀD +7.0 (c 1.0, CHCl3); H NMR
t
(CDCl3, 400 MHz): d 1.12 (s, Bu, 9H), 2.54 (br s, OH,
1H), 3.15–3.21 (m, H-3, H-5, 2H), 3.47 (dd, J = 5.6,
10.0 Hz, H-6a, 2H), 3.63 (dd, J = 5.9, 10.0 Hz, H-6b,
1H), 3.72 (dd, J = 8.1, 10.0 Hz, H-2, 1H) 3.91 (s, H-4,
1H), 4.31 (d, J = 7.6 Hz, H-1, 1H), 4.30–4.50 (m,
PhCH2, 2H), 4.60–4.75 (m, PhCH2, 2H), 7.19–7.21 (m,
Ar, 2H), 7.30–7.38 (m, Ar, 14H), 7.70–7.74 (m, Ar,
4H); 13C NMR (CDCl3, 100 MHz): d 19.21, 26.84,
65.34, 65.72, 68.96, 72.02, 73.03, 73.64, 79.38, 96.81,
127.22, 127.45, 127.60 127.86, 128.06, 128.28, 128.50,
128.56, 128.74, 132.58, 133.17, 135.86, 135.91, 137.16,
137.80; MALDI-TOFMS m/z calcd for [C36H41N3O5Si]-
Na+: 646.3. Found 646.2. Anal Calcd for C36H41N3O5-
Si: C, 69.31; H, 6.62; N, 6.74. Found: C, 69.20; H, 6.62;
N, 6.63.
23
(104 mg, 88%): ½aꢀD +23.7 (c 1.1, CHCl3); 1H NMR
t
(CDCl3, 400 MHz): d 1.15 (s, Bu, 9H), 2.89 (s, H-5,
1H), 3.25 (dd, J = 3.4, 10.2 Hz, H-3, 1H), 3.80 (dd,
J = 2.0, 12.2 Hz, H-6a, 1H), 3.91–3.96 (m, H-2, H-4,
H-6b, 3H), 4.40 (d, J = 7.8 Hz, H-1, 1H), 4.71 (s,
PhCH2, 2H), 5.41 (s, PhCH(O)2, 1H), 7.27–7.44 (m,
Ar, 14H), 7.54–7.57 (m, Ar, 2H), 7.72–7.82 (m, Ar,
4H); 13C NMR (CDCl3, 100 MHz): d 19.29, 26.93,
64.68, 66.22, 68.85, 71.48, 72.32, 77.71, 96.76, 101.04,
126.36, 127.17, 127.39, 127.67, 127.78, 128.16, 128.33,
128.98, 129.50, 129.64, 132.96, 133.29, 135.79, 135.95,
137.70, 137.79; MALDI-TOFMS m/z calcd for
[C36H39N3O5Si]Na+: 644.3. Found 644.7.
3.4. tert-Butyldiphenylsilyl 2-azido-3,6-di-O-benzyl-2-
deoxy-4-O-pentafluoropropionyl-b-D-galactopyranoside
(4b)
3.3. tert-Butyldiphenylsilyl 2-azido-3,6-di-O-benzyl-2-
deoxy-b-D-galactopyranoside (4a)
To a solution of 4a (3.93 g, 6.30 mmol) and pyridine
(0.910 mL, 11.3 mmol) in dry CH2Cl2 (100 mL), penta-
fluoropropionic anhydride (1.97 mL, 10.1 mmol) was
added portion-wise at 0 ꢁC under an Ar atmosphere
and the mixture was stirred for 2 h at 0 ꢁC. After dilu-
tion with EtOAc (200 mL), the mixture was washed with
To a mixture of 3b (7.05 g, 11.3 mmol), dried powdered
˚
3 A molecular sieves (7.06 g) and NaBH3CN (6.06 g,
96.4 mmol) in dry THF (120 mL), 4 N HCl–dioxane

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A. Ishiwata et al. / Carbohydrate Research 341 (2006) 1557–1573
ice-water (300 mL), a solution of 2 N HCl (200 mL · 2)
and brine (200 mL · 2), successively. The washed organ-
ic layer was dried over MgSO4 and concentrated in
vacuo. The crude product was purified by silica gel
column chromatography (6:1 to 5:1, hexane/EtOAc) to
3.6. 2-Azido-3,6-di-O-benzyl-2-deoxy-4-O-pentafluoro-
propionyl-D-galactopyranosyl fluoride (1)
To a solution of 4c (778 mg, 1.46 mmol) in dry CH2Cl2
(50 mL), DAST (0.430 mL, 3.22 mmol) was added at
ꢁ40 ꢁC under an Ar atmosphere. After the reaction mix-
ture was stirred for 2 h at ꢁ40 ꢁC, the reaction was
quenched by the addition of CH3OH (10 mL). The reac-
tion mixture was extracted with EtOAc (100 mL · 3)
and combined organic layers were washed with water
(200 mL · 2), satd aq NaHCO3 (200 mL) and brine
(200 mL). The washed organic layer was dried over
Na2SO4 and concentrated in vacuo. The crude product
was purified by silica gel flash column chromatography
(9:1, hexane/EtOAc) to give 1 (709 mg, 91%, a:b =
26
give 4b as a syrup (4.84 g, quantitative): ½aꢀD ꢁ12.6 (c
1
1.5, CHCl3); H NMR (CDCl3, 400 MHz): d 1.05 (s,
tBu, 9H), 3.16–3.29 (m, H-3, H-5, H-6, 4H), 3.51 (dd,
J = 7.8, 10.2 Hz, H-2, 1H), 4.25 (s, PhCH2, 1H), 4.28
(d, J = 7.8 Hz, H-1, 1H), 4.42 (d, J = 11.2 Hz, PhCH2,
1H), 4.64 (d, J = 11.2 Hz, PhCH2, 1H), 5.51 (d, J =
2.9 Hz, H-4, 1H), 7.10–7.36 (m, Ar, 16H), 7.60–7.64
(m, Ar, 4H); 13C NMR (CDCl3, 100 MHz): d 19.16,
26.77, 65.39, 65.67, 70.22, 70.83, 72.28, 73.63, 76.89,
96.77, 127.20, 127.49, 127.76 127.88, 127.95, 128.02,
128.13, 128.30, 128.37, 128.93, 129.62, 129.84, 132.37,
133.11, 135.73, 136.55 137.06, 157.54; MALDI-TOFMS
m/z calcd for [C39H40F5N3O6Si]Na+: 792.3. Found
792.6. Anal Calcd for C39H40F5N3O6Si: C, 60.85; H,
5.24; N, 5.46. Found: C, 60.79; H, 5.29; N, 5.32.
26
31:69): a-Isomer (1a): Amorphous solid: ½aꢀD +33.5 (c
1
1.1, CHCl3); H NMR (CDCl3, 400 MHz): d 3.36 (t,
J = 8.8 Hz, H-6a, 1H), 3.52–3.61 (m, H-2, H-6b, 2H),
3.92 (dd, J = 3.0, 10.5 Hz, H-3, 1H), 4.25 (t,
J = 6.0 Hz, H-5, 1H), 4.39 (d, J = 11.7 Hz, PhCH2,
1H), 4.43 (d, J = 11.7 Hz, PhCH2, 1H), 4.47 (d,
J = 11.0 Hz, PhCH2, 1H), 4.70 (d, J = 11.0 Hz, PhCH2,
1H), 5.57 (dd, J = 2.4, 52.2 Hz, H-1, 1H), 5.80 (d,
J = 2.4 Hz, H-4, 1H), 7.18–7.31 (m, Ar, 10H); 13C
NMR (100 MHz CDCl3): d 58.99, 59.23, 66.46, 69.09,
70.29, 72.22, 73.46, 73.85, 77.31, 104.62, 106.89,
127.92, 128.10 128.23, 128.30, 128.44, 128.51, 135.98,
136.80, 157.38; MALDI-TOFMS m/z calcd for
[C23H21F6N3O5]Na+: 556.1. Found 554.3. Anal Calcd
for C23H21F6N3O5: C, 51.79; H, 3.97; N, 7.88. Found:
C, 52.08; H, 3.96; N, 7.66. b-Isomer (1b): Amorphous
3.5. 2-Azido-3,6-di-O-benzyl-2-deoxy-4-O-pentafluoro-
propionyl-D-galactopyranose (4c)
To a solution of 4b (4.95 g, 6.43 mmol) in THF
(210 mL), HF–pyridine (11 mL) was added at rt. After
stirring for 60 h at rt, the reaction was quenched by
the addition of powdered NaHCO3. After dilution with
EtOAc (100 mL) and water (100 mL), the reaction mix-
ture was extracted with EtOAc (100 mL · 4) and com-
bined organic layers were washed with brine (500 mL).
The washed organic layer was dried over Na2SO4 and
concentrated in vacuo. The crude product was purified
by silica gel column chromatography (4:1, hexane/
EtOAc,) to give 4c as a syrup (3.20 g, 94%, a:b =
25
solid; ½aꢀD ꢁ40.1 (c 1.0, CHCl3); 1H NMR (CDCl3,
400 MHz): d 3.40–3.45 (m, H-3, H-6a, 2H), 3.49–3.60
(m, H-2, H-6b, 2H), 3.76 (t, J = 6.8 Hz, H-5, 1H), 4.40
(dd, J = 11.7, 18.3 Hz, PhCH2, 2H), 4.45 (d,
J = 11.0 Hz, PhCH2, 1H), 4.67 (d, J = 11.2 Hz, PhCH2,
1H), 4.88 (dd, J = 7.6, 51.7 Hz, H-1, 1H), 5.63 (s, H-4,
1H), 7.16–7.30 (m, Ar, 10H); 13C NMR (CDCl3,
100 MHz): d 62.42, 62.62, 66.34, 69.25, 71.23, 71.28,
73.89, 76.40, 76.49, 106.52, 108.68, 127.99, 128.15
128.23, 128.25, 128.43, 128.52, 135.98, 136.70, 157.47;
MALDI-TOFMS m/z calcd for [C23H21F6N3O5]Na+:
556.1. Found 556.6. Anal Calcd for C23H21F6N3O5: C,
51.79; H, 3.97; N, 7.88. Found: C, 51.70; H, 3.99; N,
7.83.
23
1
71:29): ½aꢀD +23.6 (c 1.1, CHCl3); H NMR (CDCl3,
400 MHz, a-isomer): d 3.33–3.43 (m, H-6a, 1H), 3.52
(dd, J = 6.4, 10.2 Hz, H-6b, 1H), 3.52 (dd, J = 3.2,
10.5 Hz, H-2, 1H), 3.68 (br s, OH, 1H), 3.95 (dd,
J = 3.2, 10.5 Hz, H-3, 1H), 4.31 (t, J = 6.0 Hz, H-5,
1H), 4.36–4.47 (m, PhCH2, 3H), 4.66 (d, J = 10.7 Hz,
PhCH2, 1H), 5.22 (br s, H-1, 1H), 5.64 (br s, H-4,
1H), 7.17–7.28 (m, Ar, 10H); b-isomer: d 3.33–3.43 (m,
H-3, H-6a, 2H), 3.50–3.54 (m, H-2, H-6b, 2H), 3.38 (t,
J = 6.0 Hz, H-5, 1H), 4.05 (br s, OH, 1H), 4.37–4.47
(m, H-1, H-2, PhCH2, 5H), 4.65 (d, J = 11.5 Hz,
PhCH2, 1H), 5.56 (br s, H-1, 1H), 7.17–7.28 (m, Ar,
10H); 13C NMR (CDCl3, 100 MHz): d 59.78, 63.74,
66.91, 67.06, 67.58, 70.14, 71.31, 71.51, 72.18, 72.38,
73.63, 73.76, 73.80, 76.94, 92.03, 96.03, 128.00, 128.04,
128.07, 128.12, 128.16, 128.20, 128.35, 128.48, 128.49,
136.26, 136.34, 136.73, 136.78, 157.60; MALDI-
TOFMS m/z calcd for [C23H22F5N3O6]Na+: 554.1.
Found 554.3. Anal Calcd for C23H22F5N3O6: C,
51.98; H, 4.17; N, 7.91. Found: C, 51.92; H, 4.34; N,
7.83.
3.7. tert-Butyldiphenylsilyl 2,3,4,6-tetra-O-acetyl-b-D-
glucopyranosyl-(1!3)-2-azido-4,6-O-benzylidene-2-
deoxy-b-D-galactopyranoside (6a)
To a mixture of 3a (1.37 g, 2.58 mmol) and dried pow-
˚
dered 3 A molecular seives (1.50 g) in dry CH2Cl2
(25 mL), methyl 2,3,4,6-tetra-O-acetyl-1-thio-b-D-gluco-
pyranoside (2, 1.17 g, 3.09 mmol) was added at ꢁ15 ꢁC
under an Ar atmosphere. To the reaction mixture, NIS
(1.48 g, 6.58 mmol) was added in dry CH2Cl2 (10 mL)–

A. Ishiwata et al. / Carbohydrate Research 341 (2006) 1557–1573
1565
dry toluene (20 mL) and trifluoromethanesulfonic acid
(0.210 mL) and the mixture was stirred for 2 h at the
same temperature. The reaction mixture was quenched
by the addition of satd aq NaHCO3 (40 mL) and filtered
through Celite. The filtrate was treated with 20%
Na2S2O3 aq (40 mL) and extracted with CH2Cl2
(40 mL · 4). The combined organic layers were washed
with brine (100 mL), dried over Na2SO4, and concen-
trated in vacuo. The crude product was purified by silica
gel column chromatography (1:10, acetone/toluene) to
OH, 1H), 3.23 (t, J = 5.9 Hz, H-5Gal, 1H), 3.28 (dd,
J = 3.2, 10.3 Hz, H-3Gal
1H), 3.47 (dd, J = 5.6,
9.8 Hz, H-6aGal, 1H), 3.65–3.71 (m, H-2Gal, H-5Glc, H-
6bGal, 3H), 3.93 (s, H-4Gal, 1H), 4.09–4.17 (m, H-6Glc
,
,
2H), 4.31 (d, J = 7.8 Hz, H-1Gal, 1H), 4.38 (s, PhCH2,
2H), 4.69 (d, J = 8.1 Hz, H-1Glc, 1H), 5.03–5.08 (m,
H-2Glc, H-4Glc, 2H), 5.20 (t, J = 10.0 Hz, H-3Glc, 1H),
7.18–7.20 (m, Ar, 2H), 7.26–7.40 (m, Ar, 9H), 7.69–
7.73 (m, Ar, 4H); 13C NMR (CDCl3, 100 MHz): d
19.10, 20.55, 20.59, 26.74, 61.69, 65.23, 67.57, 68.20,
68.81, 70.96, 71.92, 72.42, 73.01, 73.50, 77.20, 81.34,
96.73, 101.40, 127.17, 127.41, 127.53, 128.08, 128.20,
128.89, 129.54, 129.72, 132.42, 132.94, 135.77, 135.87,
137.79, 169.14, 169.23, 170.00, 170.38; MALDI-
TOFMS m/z calcd for [C43H53N3O14Si]Na+: 886.3.
Found 886.8. Anal Calcd for C43H53N3O14Si: C,
59.78; H, 6.18; N, 4.86. Found: C, 59.91; H, 6.14; N,
4.58.
26
give 6a as an amorphous solid (1.70 g, 77%): ½aꢀD
1
+18.9 (c 1.1, CHCl3); H NMR (CDCl3, 400 MHz): d
t
1.13 (s, Bu, 9H), 2.00 (s, Ac, 3H), 2.03 (s, Ac, 3H),
2.05 (s, Ac, 3H), 2.07 (s, Ac, 3H), 2.96 (s, H-5Gal, 1H),
3.34 (dd, J = 3.4, 10.5 Hz, H-3Gal, 1H), 3.64 (ddd,
J = 2.4, 4.4, 6.8 Hz, H-5Glc, 1H), 3.84–3.89 (m, H-2Gal
,
H-6aGal, 2H), 3.96 (d, J = 12.2 Hz, H-6bGal, 1H),
4.12–4.15 (m, H-4Gal, H-6aGlc, 2H), 4.25 (dd, J = 2.4,
12.2 Hz, H-6bGlc, 1H), 4.40 (d, J = 7.8 Hz, H-1Gal
,
1H), 4.79 (d, 7.8 Hz, H-1Glc, 1H), 5.05 (dd, J = 7.8,
9.3 Hz, H-2Glc, 1H), 5.10 (t, J = 9.8 Hz, H-4Glc, 1H),
5.20 (t, J = 9.3 Hz, H-3Glc, 1H), 5.48 (s, PhCH, 1H),
7.32–7.45 (m, Ar, 9H), 7.54–7.56 (m, Ar, 2H), 7.71–
7.78 (m, Ar, 4H); 13C NMR (CDCl3, 100 MHz): d
19.25, 20.65, 20.68, 20.82, 26.88, 61.61, 64.82, 66.36,
68.24, 68.66, 71.27, 71.80, 72.87, 74.86, 78.86, 96.85,
100.60, 101.76, 126.23, 127.19, 127.43, 128.08, 128.82,
129.57, 129.71, 132.85, 133.07, 135.76, 135.97, 137.83,
169.18, 169.20, 170.17, 170.33; MALDI-TOFMS m/z
calcd for [C43H51N3O14Si]Na+: 884.3. Found 884.9.
Anal Calcd for C43H51N3O14Si: C, 59.92; H, 5.96; N,
4.87. Found: C, 59.91; H, 5.98; N, 4.70.
3.9. tert-Butyldiphenylsilyl 2,3,4,6-tetra-O-acetyl-b-D-
glucopyranosyl-(1!3)-2-azido-6-O-benzyl-2-deoxy-4-O-
pentafluoropropionyl-b-D-galactopyranoside (6c)
To a solution of 6b (3.73 g, 4.32 mmol) and pyridine
(0.625 mL, 7.77 mmol) in dry CH2Cl2 (100 mL), penta-
fluoropropionic anhydride (1.26 mL, 6.48 mmol) was
added portion-wise at 0 ꢁC under an Ar atmosphere
and the mixture was stirred for 1 h at the same temper-
ature. The reaction was quenched by the addition of
0.2 N aq HCl (50 mL) and a separated organic layer
was washed with water (80 mL) and brine (80 mL).
The washed organic layer was dried over MgSO4 and
concentrated in vacuo. The crude product was purified
by silica gel column chromatography (4:1 to 7:3, hex-
ane/EtOAc) to give 6c as an amorphous solid (3.70 g,
3.8. tert-Butyldiphenylsilyl 2,3,4,6-tetra-O-acetyl-b-D-
glucopyranosyl-(1!3)-2-azido-6-O-benzyl-2-deoxy-b-D-
galactopyranoside (6b)
25
85%): ½aꢀD ꢁ1.4 (c 1.0, CHCl3); 1H NMR (CDCl3,
t
400 MHz): d 1.11 (s, Bu, 9H), 2.00 (s, Ac, 6H), 2.02
To a mixture of 6a (1.10 g, 1.28 mmol) and dried pow-
dered 4 A molecular seives (3.02 g) in dry THF
(s, Ac, 3H), 2.06 (s, Ac, 3H), 3.22 (dd, J = 2.0, 6.3 Hz,
H-6Gal, 2H), 3.36 (t, J = 6.3 Hz, H-5Gal, 1H), 3.47 (dd,
˚
(90 mL), NaBH3CN (718 mg, 10.9 mmol) was added at
0 ꢁC under an Ar atmosphere, and the mixture was stir-
red for 30 min at the same temperature. HCl (4 N)–di-
oxane (6.40 mL, 25.6 mmol) was added portion-wise to
the reaction mixture and the mixture was stirred for 4 h
at the same temperature. The reaction mixture was diluted
with EtOAc (100 mL), quenched by the addition of satd
aq NaHCO3 (100 mL), and filtered through Celite. The
filtrate was extracted with EtOAc (50 mL · 3) and com-
bined organic layers were washed with brine (300 mL).
The washed organic layer was dried over Na2SO4 and
concentrated in vacuo. The crude product was purified
by silica gel column chromatography (1:1, EtOAc/
CHCl3) to give 6b as an amorphous solid (990 mg,
J = 3.2, 10.2 Hz, H-3Gal, 1H), 3.56–3.63 (m, H-2Gal
,
H-5Glc, 2H), 4.06 (dd, J = 4.2, 12.2 Hz, H-6aGlc, 1H),
4.22 (dd, J = 2.4, 12.2 Hz, H-6bGlc, 1H), 4.24 (d,
J = 11.4 Hz, PhCH2, 1H), 4.27 (d, J = 11.4 Hz, PhCH2,
1H), 4.36 (d, J = 7.6 Hz, H-1Gal
, 1H), 4.71 (d,
J = 7.8 Hz, H-1Glc, 1H), 4.89 (dd, J = 8.0, 9.5 Hz,
H-2Glc, 1H), 5.07 (t, J = 9.7 Hz, H-4Glc, 1H), 5.17 (t,
J = 9.5 Hz, H-3Glc, 1H), 5.51 (d, J = 3.2 Hz, H-4Gal
,
1H), 7.14–7.17 (m, Ar, 2H), 7.28–7.41 (m, Ar, 9H),
7.67–7.69 (m, Ar, 4H); 13C NMR (CDCl3, 100 MHz):
d 19.14, 20.49, 20.56, 20.63, 26.75, 61.19, 65.77, 67.18,
68.02, 71.18, 71.46, 71.80, 72.60, 72.93, 73.68, 77.15,
77.21, 96.79, 101.20, 127.23, 127.54, 127.79, 128.82,
128.30, 129.69, 129.93, 132.18, 132.92, 135.75, 137.14,
156.75, 168.83, 169.10, 170.15, 170.59; MALDI-
TOFMS m/z calcd for [C46H52F5N3O15Si]Na+: 1032.3.
Found 1032.2. Anal Calcd for C46H52F5N3O15Si: C,
24
90%): ½aꢀD +8.0 (c 1.1, CHCl3); 1H NMR (CDCl3,
t
400 MHz): d 1.11 (s, Bu, 9H), 2.01 (s, Ac, 3H), 2.03
(s, Ac, 3H), 2.05 (s, Ac, 3H), 2.09 (s, Ac, 3H), 2.59 (s,

1566
A. Ishiwata et al. / Carbohydrate Research 341 (2006) 1557–1573
54.70; H, 5.19; N, 4.16. Found: C, 54.68; H, 5.21; N,
4.06.
aq NaHCO3 (50 mL). The reaction mixture was ex-
tracted with CH2Cl2 (50 mL · 4) and combined organic
layers were washed with water (50 mL · 2) and satd aq
NaHCO3 (100 mL), successively, dried over Na2SO4,
and concentrated in vacuo. The crude product was puri-
fied by silica gel flash column chromatography (5:1 to
4:1, hexane/EtOAc) to give 7 (2.15 g, 94%, a:b =
3.10. 2,3,4,6-Tetra-O-acetyl-b-D-glucopyranosyl-(1!3)-
2-azido-6-O-benzyl-2-deoxy-4-O-pentafluoropropionyl-D-
galactopyranose (6d)
25
To a solution of 6c (399 mg, 0.395 mmol) in THF
(15 mL), HF–pyridine (0.700 mL) was added at rt. The
mixture was stirred for 24 h at the same temperature
and then the mixture was quenched by the addition of
powdered NaHCO3, diluted with EtOAc (20 mL) and
water (20 mL), and extracted with EtOAc (20 mL · 4).
The combined organic layers were washed with brine
(50 mL), dried over Na2SO4, and concentrated in vacuo.
The crude product was purified by silica gel column
chromatography (3:1 to 1:2, hexane–EtOAc) to give 6d
as an amorphous solid (301 mg, 99%, a:b = 74:26):
35:65). a-Isomer (7a): Amorphous solid; ½aꢀD +25.3 (c
1
1.1, CHCl3); H NMR (CDCl3, 400 MHz): d 2.00 (s,
Ac, 3H), 2.01 (s, Ac, 3H), 2.02 (s, Ac, 3H), 2.03 (s,
Ac, 3H), 3.40 (dd, J = 7.4, 9.8 Hz, H-6aGal, 1H), 3.55
(dd, J = 5.4, 9.3 Hz, H-6bGal, 1H), 3.65–3.74 (m, H-
2Gal, H-5Glc, 2H), 4.09 (dd, J = 4.4, 12.2 Hz, H-6aGlc
,
1H), 4.16 (dd, J = 3.4, 10.7 Hz, H-3Gal, 1H), 4.28–4.33
(m, H-5Gal, H-6bGlc, 2H), 4.44 (d, J = 11.7 Hz, PhCH2,
1H), 4.49 (d, J = 11.7 Hz, PhCH2, 1H), 4.81 (d,
J = 7.8 Hz, H-1Glc, 1H), 4.91 (t, J = 9.8 Hz, H-1Glc
,
1H), 5.10 (t, J = 9.8 Hz, H-4Glc, 1H), 5.19 (t, J =
9.3 Hz, H-3Glc, 1H), 5.72 (dd, J = 2.4, 52.2 Hz, H-1Gal
26
½aꢀD +28.2 (c 1.0, CHCl3); 1H NMR (CDCl3, 400
,
MHz) a-isomer: d 2.00–2.04 (m, Ac, 12H), 3.54–3.70
(m, H-2Gal, H-5Glc, H-6Gal, 4H), 4.09 (dd, J = 4.4,
12.2 Hz, H-6aGlc, 1H), 4.20 (dd, J = 2.9, 10.5 Hz, H-
3Gal, 1H), 4.27 (dd, J = 2.4, 8.3 Hz, H-6bGlc, 1H), 4.40
(t, J = 5.9 Hz, H-5Gal, 1H), 4.46–4.49 (m, PhCH2, 2H),
4.78 (d, J = 8.1 Hz, H-1Glc, 1H), 4.90 (dd, J = 8.1,
9.3 Hz, H-2Glc, 1H), 5.09 (t, J = 9.8 Hz, H-4Glc, 1H),
1H), 5.82 (d, J = 2.9 Hz, H-4Gal, 1H), 7.27–7.36 (m,
Ar, 5H); 13C NMR (CDCl3, 100 MHz): d 20.55, 20.57,
20.62, 20.63, 59.36, 59.59, 61.14, 67.03, 67.88, 69.66,
69.70, 71.16, 72.07, 72.65, 73.44, 73.82, 74.40, 77.32,
101.25, 104.58, 106.85, 127.94, 127.99, 128.42, 136.81,
156.57, 168.89, 169.11, 170.11, 170.57; MALDI-
TOFMS m/z calcd for [C30H33F6N3O14]Na+: 796.2.
Found 796.5. Anal Calcd for C30H33F6N3O14: C,
46.58; H, 4.30; N, 5.43. Found: C, 46.51; H, 4.28; N,
5.18 (t, J = 9.5 Hz, H-3Glc, 1H), 5.40 (br s, H-1Gal
,
1H), 5.71 (d, J = 2.7 Hz, H-4Gal, 1H), 7.18–7.36 (m,
Ar, 5H); b-isomer: d 2.00–2.04 (m, Ac, 12H), 3.54–3.70
(m, H-2Gal, H-3Gal, H-5Glc, H-6Gal, 5H), 3.81 (t,
J = 6.6 Hz, H-5Gal, 1H), 4.09 (dd, J = 4.4, 12.2 Hz, H-
6aGlc, 1H), 4.27 (dd, J = 2.4, 8.3 Hz, H-6bGlc, 1H),
4.46–4.49 (m, PhCH2, 2H), 4.51–4.59 (m, H-1Gal, 1H),
4.76 (d, J = 8.6 Hz, H-1Glc, 1H), 4.89 (dd, J = 8.6,
9.3 Hz, H-2Glc, 1H), 5.09 (t, J = 9.8 Hz, H-4Glc, 1H),
5.18 (t, J = 9.5 Hz, H-3Glc, 1H), 5.60 (d, J = 3.2 Hz,
H-4Gal, 1H) and 7.18–7.36 (m, Ar, 5H); 13C NMR
(CDCl3, 100 MHz): d 20.46, 20.55, 20.57, 20.61, 59.99,
61.21, 64.16, 67.42, 67.55, 67.95, 67.98, 68.02, 71.18,
71.84, 71.89, 72.54, 72.73, 72.89, 73.76, 73.84, 74.53,
74.56, 77.20, 92.08, 96.22, 101.26, 101.29, 127.97,
128.00, 128.41, 128.44, 136.83, 136.91, 156.86, 168.98,
169.15, 170.18, 170.68; MALDI-TOFMS m/z calcd for
[C30H34F5N3O15]Na+: 794.2. Found 794.5. Anal Calcd
for C30H34F5N3O15: C, 46.70; H, 4.44; N, 5.45. Found:
C, 46.84; H, 4.43; N, 5.53.
25
5.36. b-Isomer (7b): Amorphous solid; ½aꢀD ꢁ11.6 (c
1
1.1, CHCl3); H NMR (CDCl3, 400 MHz): d 2.00 (s,
Ac, 3H), 2.02 (s, Ac, 3H), 2.03 (s, Ac, 3H), 2.04 (s,
Ac, 3H), 3.45 (dd, J = 7.1, 9.5 Hz, H-6aGal, 1H), 3.59–
3.68 (m, H-2Gal, H-3Gal, H-5Glc, H-6bGal, 4H), 3.87 (t,
J = 6.3 Hz, H-5Gal, 1H), 4.08 (dd, J = 4.1, 12.4 Hz, H-
6aGlc, 1H), 4.29 (dd, J = 4.1, 12.7 Hz, H-6bGlc, 1H),
4.44 (d, J = 11.7 Hz, PhCH2, 1H), 4.49 (d, J =
11.7 Hz, PhCH2, 1H), 4.77 (d, J = 7.8 Hz, H-1Glc, 1H),
4.88 (dd, J = 8.1, 9.3 Hz, H-2Glc, 1H), 5.02 (dd, J =
7.3, 46.3 Hz, H-1Gal, 1H), 5.10 (t, J = 9.8 Hz, H-4Glc
1H), 5.19 (t, J = 9.5 Hz, H-3Glc, 1H), 5.66 (br s, H-4Gal
,
,
1H), 7.27–7.34 (m, Ar, 5H); 13C NMR (CDCl3, 100
MHz): d 20.49, 20.57, 20.62, 61.07, 62.87, 63.09, 66.85,
67.90, 71.14, 71.85, 71.90, 71.98, 72.13, 72.50, 73.92,
76.84, 101.25, 106.53, 108.69, 128.02, 128.07, 136.74,
156.67, 168.78, 169.08, 170.13, 170.60; MALDI-
TOFMS m/z calcd for [C30H33F6N3O14]Na+: 796.2.
Found 796.4. Anal Calcd for C30H33F6N3O14: C, 46.58;
H, 4.30; N, 5.43. Found: C, 46.85; H, 4.27; N, 5.44.
3.11. 2,3,4,6-Tetra-O-acetyl-b-D-glucopyranosyl-(1!3)-
2-azido-6-O-benzyl-2-deoxy-4-O-pentafluoropropionyl-D-
galactopyranosyl fluoride (7)
3.12. Typical procedure for a-selective glycosylation: tert-
Butyldiphenylsilyl 2-azido-3,6-di-O-benzyl-2-deoxy-4-O-
pentafluoropropionyl-D-galactopyranosyl-(1!4)-2-azido-
3,6-di-O-benzyl-2-deoxy-b-D-galactopyranoside (5)
To a solution of 6d (2.29 g, 2.97 mmol) in dry CH2Cl2
(60 mL), DAST (0.780 mL, 5.94 mmol) was added at
ꢁ40 ꢁC under an Ar atmosphere. The reaction mixture
was stirred for 2 h at the same temperature, then
quenched by the addition of CH3OH (25 mL) and satd
A mixture of AgClO4 (43.1 mg, 0.208 mmol), Cp2HfCl2
˚
(39.5 mg, 0.104 mmol), and dried powdered 4 A mole-

A. Ishiwata et al. / Carbohydrate Research 341 (2006) 1557–1573
1567
cular sieves (225 mg) in dry CHCl3 (2.10 mL) was stirred
for 30 min at rt under an Ar atmosphere. To the mix-
ture, a solution of 1b (25.6 mg, 0.0480 mmol) and 4a
(25.0 mg, 0.0400 mmol) was added in dry CHCl3
(2.1 mL) at the same temperature and the mixture was
stirred for 42 h at the same temperature under an Ar
atmosphere. The reaction mixture was diluted with
EtOAc (10 mL), quenched by the addition of satd aq
NaHCO3 (10 mL), and filtered through Celite. The fil-
trate was extracted with EtOAc (10 mL · 3) and com-
bined organic layers were washed with brine (30 mL).
The washed organic layer was dried over Na2SO4 and
concentrated in vacuo. The crude product was purified
by gel filtration chromatography (1:1, EtOAc/toluene)
to give 5 as a syrup (41.8 mg, 92%, a:b = 94:6). a-Isomer
136.61, 136.92, 137.69, 138.19 (Ar), 157.42; MALDI-
TOFMS m/z calcd for [C59H61F5N6O10Si]Na+: 1159.4.
Found 1160.0. Anal Calcd for C59H61F5N6O10Si: C,
62.31; H, 5.41; N, 7.39. Found: C, 62.43; H, 5.41; N, 7.22.
3.13. 4-O-Acetyl-2-azido-3,6-di-O-benzyl-2-deoxy-D-
galactopyranose (4d)
To a solution of 4a (605 mg, 0.969 mmol) in pyridine
(25 mL), Ac2O (15 mL) was added at rt and the mixture
was stirred for 12 h at the same temperature. The reac-
tion mixture was diluted with EtOAc (50 mL), quenched
by the addition of a solution of aq 1 N HCl, stirred at rt
for 30 min, and extracted with EtOAc (30 mL · 3) and
the organic layer was washed with brine (50 mL · 2)
and water (50 mL · 2). The washed organic layer was
dried over Na2SO4 and concentrated in vacuo. To a
solution of the crude product in THF (25 mL), HF–pyri-
dine (2.0 mL) was added at rt. After the reaction mix-
ture was stirred for 18 h at the same temperature, the
mixture was quenched by the addition of powdered
NaHCO3. The reaction mixture was diluted with EtOAc
(20 mL) and water (30 mL) added, and the reaction mix-
ture was extracted with EtOAc (30 mL · 3). The com-
bined organic layers were washed with brine (50 mL),
dried over MgSO4, and concentrated in vacuo. The
crude product was purified by silica gel column chroma-
tography (4:1, hexane/EtOAc) to give 4d as a syrup
23
(5a): Syrup; ½aꢀD +53.9 (c 1.0, CHCl3); 1H NMR
t
(CDCl3, 400 MHz): d 1.12 (s, Bu, 9H), 3.07–3.11 (m,
H-31, H-6a1, 2H), 3.14–3.24 (m, H-62, H-6b1, 3H),
3.46 (dd, J = 3.4, 10.7 Hz, H-22, 1H), 3.63 (dd,
J = 7.6, 10.5 Hz, H-21, 1H), 3.79 (t, J = 9.0 Hz, H-51,
1H), 4.01 (d, J = 2.9 Hz, H-41, 1H), 4.10 (dd, J = 11.7,
19.3 Hz, PhCH2, 2H), 4.14 (dd, J = 2.9, 10.7 Hz, H-32,
1H), 4.28 (d, J = 7.6 Hz, H-11, 1H), 4.40 (s, PhCH2,
2H), 4.50 (d, J = 12.2 Hz, PhCH2, 1H), 4.60 (d,
J = 10.2 Hz, PhCH2, 1H), 4.67 (dd, J = 5.9, 8.8 Hz, H-
52, 1H), 4.75 (d, J = 11.8 Hz, PhCH2, 1H), 4.85 (d,
J = 10.5 Hz, PhCH2, 1H), 4.89 (d, J = 3.7 Hz, H-12,
1H), 5.90 (br s, H-42, 1H), 7.14–7.16 (m, Ar, 2H),
7.22–7.41 (m, Ar, 24H), 7.67–7.72 (m, Ar, 4H); 13C
NMR (CDCl3, 100 MHz): d 19.25, 26.79, 26.82, 26.86,
59.44, 66.23, 66.64, 66.74, 71.21, 71.98, 72.13, 72.27,
72.52, 73.32, 73.40, 77.21, 78.85, 96.92, 98.76, 127.13,
127.21, 127.42, 127.78, 127.81, 127.91, 127.99, 128.01,
128.16, 128.30. 128.31, 128.39, 128.44, 128.47, 128.49,
129.52, 129.73, 132.63, 133.23, 135.80, 135.90, 135.96,
136.42, 137.11, 137.31, 137.36; MALDI-TOFMS m/z
calcd for [C59H61F5N6O10Si]Na+: 1159.4. Found
1159.9. Anal Calcd for C59H61F5N6O10Si: C, 62.31; H,
5.41; N, 7.39. Found: C, 62.43; H, 5.43; N, 7.31. b-Iso-
24
(372 mg, 90%, a:b = 61:39): ½aꢀD +33.0 (c 1.3, CHCl3);
1H NMR (CDCl3, 400 MHz): a-isomer: d 2.07 (s, Ac,
3H), 3.45–3.58 (m, H-6, 2H), 3.66–3.71 (m, H-2, 1H),
3.78 (br s, OH, 1H), 3.97 (dd, J = 3.2, 10.5 Hz, H-3,
1H), 4.45 (t, J = 6.0 Hz, H-5, 1H), 4.47–4.50 (m,
PhCH2, 2H), 4.57 (d, J = 12.0 Hz, PhCH2, 1H), 4.75
(d, J = 10.7 Hz, PhCH2, 1H), 5.33 (t, J = 3.42 Hz, H-
1, 1H), 5.58 (d, J = 3.17 Hz, H-4, 1H), 7.17–7.38 (m,
Ar, 10H). b-Isomer: d 2.08 (s, Ac, 3H), 3.35 (dd,
J = 3.17, 10.0 Hz, H-3, 1H), 3.45–3.58 (m, H-2, H-6a,
2H), 3.66–3.71 (m, H-5, H-6b, 2H), 4.23 (br s, OH,
1H), 4.47–4.50 (m, H-1, PhCH2, 3H), 4.57 (d,
J = 12.0 Hz, PhCH2, 1H), 4.73 (d, J = 11.2 Hz, PhCH2,
1H), 5.49 (d, J = 3.2 Hz, H-4, 1H), 7.17–7.38 (m, Ar,
10H); 13C NMR (CDCl3, 100 MHz): d 20.82, 20.85,
59.76, 63.72, 65.61, 66.88, 68.00, 68.21, 71.67, 71.84,
72.41, 73.58, 73.67, 74.09, 77.21, 77.68, 92.22, 96.07,
127.88, 127.92, 128.00, 128.23, 128.32, 128.39, 128.43,
136.79, 136.89, 137.13, 137.20, 170.14; MALDI-
TOFMS m/z calcd for [C22H25N3O6]Na+: 450.2. Found
450.2. Anal Calcd for C22H25N3O6: C, 61.82; H, 5.90; N,
9.83. Found: C, 61.53; H, 5.72; N, 9.80.
24
1
mer (5b): Syrup; ½aꢀD ꢁ11.2 (c 1.3, CHCl3); H NMR
t
(CDCl3, 400 MHz): d 1.05 (s, Bu, 9H), 3.14–3.20 (m,
H-31, H-32, H-6a1, H-6a2, 4H), 3.23–3.28 (m, H-6b1,
H-6b2, 2H), 3.39 (t, J = 5.9 Hz, H-52, 1H), 3.43–3.46
(m, H-22, H-51, 2H), 3.87 (dd, J = 7.8, 10.2 Hz, H-21,
1H), 3.95 (br s, H-41, 1H), 4.22–4.25 (m, PhCH2, 4H),
4.29 (d, J = 7.6 Hz, H-11, 1H), 4.48 (d, J = 11.7 Hz,
PhCH2, 1H), 4.50 (d, J = 12.2 Hz, PhCH2, 1H), 4.55
(d, J = 8.1 Hz, H-12, 1H), 4.67 (d, J = 11.7 Hz, PhCH2,
1H), 4.72 (d, J = 12.2 Hz, PhCH2, 1H), 5.53 (d, J =
3.6 Hz, H-42, 1H), 7.07–7.24 (m, Ar, 2H), 7.28–7.31
(m, Ar, 24H), 7.65–7.68 (m, Ar, 4H); 13C NMR (CDCl3,
100 MHz): d 19.20, 26.81, 26.82, 63.02, 65.81, 66.60,
68.78, 70.24, 70.58, 70.76, 72.39, 73.07, 73.19, 73.67,
76.29, 77.21, 80.56, 96.92, 101.16, 127.12, 127.17,
127.40, 127.80, 127.97, 128.02, 128.15, 128.34, 128.39,
128.46, 129.45, 129.64, 132.75, 133.26, 135.85, 135.94,
3.14. 4-O-Acetyl-2-azido-3,6-di-O-benzyl-2-deoxy-D-
galactopyranosyl fluoride (8)
To a solution of 4d (236 mg, 0.552 mmol) in dry CH2Cl2
(10 mL), DAST (0.110 mL, 0.829 mmol) was added at

1568
A. Ishiwata et al. / Carbohydrate Research 341 (2006) 1557–1573
ꢁ40 ꢁC under an Ar atmosphere. After the reaction mix-
ture was stirred for 20 h at the same temperature, the
reaction was quenched by the addition of CH3OH
(10 mL) and satd aq NaHCO3 (30 mL). The reaction
mixture was extracted with CH2Cl2 (50 mL · 3) and
combined organic layers were washed with water
(100 mL · 2) and brine (100 mL). The washed organic
layer was dried over MgSO4 and concentrated in vacuo.
The crude product was purified by silica gel flash col-
umn chromatography (19:1, hexane/EtOAc) to give 8
3.22 (m, H-6b1, H-6b2, 2H), 3.52 (dd, J = 3.4, 10.7 Hz,
H-22, 1H), 3.61 (dd, J = 7.8, 10.5 Hz, H-21, 1H), 3.73
(t, J = 9.0 Hz, H-51, 1H), 3.97 (d, J = 2.4 Hz, H-41,
1H), 4.02 (d, J = 12.2 Hz, PhCH2, 1H), 4.05 (dd,
J = 2.7, 10.7 Hz, H-32, 1H), 4.20 (d, J = 7.8 Hz, H-11,
1H), 4.21 (d, J = 11.5 Hz, PhCH2, 1H), 4.27 (d,
J = 11.7 Hz, PhCH2, 1H), 4.35 (d, J = 11.7 Hz, PhCH2,
1H), 4.44 (d, J = 12.4 Hz, PhCH2, 1H), 4.49 (d,
J = 10.2 Hz, PhCH2, 1H), 4.52 (t, J = 7.6 Hz, H-52,
1H) 4.70 (d, J = 12.4 Hz, PhCH2, 1H), 4.82 (d,
J = 10.0 Hz, PhCH2, 1H), 4.90 (d, J = 3.4 Hz, H-12,
1H), 5.70 (br s, H-42, 1H), 7.11–7.37 (m, Ar, 26H),
7.60–7.65 (m, Ar, 4H); 13C NMR (CDCl3, 100 MHz):
d 19.22, 20.88, 26.84, 59.49, 65.84, 66.52, 66.63, 67.41,
67.81, 71.59, 71.83, 72.12, 72.63, 73.26, 73.39, 73.72,
78.75, 96.92, 99.07, 127.12, 127.31, 127.40, 127.60,
127.66, 127.77, 127.92, 127.99, 128.21, 128.36, 128.63,
129.48, 129.68, 132.66, 133.28, 135.80, 135.92, 136.99,
137.48, 169.86; MALDI-TOFMS m/z calcd for
[C58H64N6O10Si]Na+: 1055.4. Found 1056.8. Anal
Calcd for C58H64N6O10Si: C, 67.42; H, 6.24; N, 8.13.
Found: C, 67.51; H, 6.32; N, 7.91. b-Isomer (9b): Syrup;
24
(195 mg, 82%, a:b = 33:67). a-Isomer (8a): Syrup; ½aꢀD
1
+48.1 (c 1.1, CHCl3); H NMR (CDCl3, 400 MHz): d
2.06 (s, Ac, 3H), 3.48 (dd, J = 6.8, 9.5 Hz, H-6a, 1H),
3.56 (dd, J = 6.1, 9.5 Hz, H-6b, 1H), 3.73 (ddd,
J = 2.7, 10.5, 25.6 Hz, H-2, 1H), 3.95 (dd, J = 2.9,
10.5 Hz, H-3, 1H), 4.27 (t, J = 6.6 Hz, H-5, 1H), 4.47
(d, J = 12.0 Hz, PhCH2, 1H), 4.50 (d, J = 10.7 Hz,
PhCH2, 1H), 4.58 (d, J = 12.0 Hz, PhCH2, 1H), 4.80
(d, J = 10.7 Hz, PhCH2, 1H), 5.65 (dd, J = 2.7,
52.7 Hz, H-1, 1H), 5.72 (d, J = 2.9 Hz, H-4, 1H), 7.29–
7.38 (m, Ar, 10H); 13C NMR (CDCl3, 100 MHz): d
20.71, 58.97, 59.21, 65.76, 67.47, 70.33, 70.36, 71.64,
73.61, 73.96, 104.89, 107.15, 127.84, 127.90, 128.03,
128.38, 128.40, 136.55, 137.19, 169.68; MALDI-
TOFMS m/z calcd for [C22H24FN3O5]Na+: 452.2.
Found 452.9. Anal Calcd for C22H24FN3O5: C, 61.53;
H, 5.63; N, 9.78. Found: C, 61.60; H, 5.50; N, 9.64. b-
24
½aꢀD ꢁ11.2 (c 1.0, CHCl3); 1H NMR (CDCl3, 400 MHz):
d 1.11 (s, tBu, 9H), 2.07 (s, Ac, 3H), 3.18–3.23 (m, H-31,
H-32, H-6a1, H-6a2, 4H), 3.35–3.40 (m, H-6b1, H-6b2,
2H), 3.45 (t, J = 6.3 Hz, H-51, 1H), 3.57–3.64 (m, H-
22, H-52, 2H), 3.52 (dd, J = 3.4, 10.7 Hz, H-22, 1H),
3.61 (dd, J = 7.8, 10.5 Hz, H-21, 1H), 3.73 (t,
J = 9.0 Hz, H-51, 1H), 3.96 (dd, J = 7.8, 10.5 Hz, H-
21, 1H), 4.06 (d, J = 2.4 Hz, H-41, 1H), 4.29 to ꢂ4.38
(m, H-11, PhCH2, 4H), 4.43 (d, J = 11.7 Hz, PhCH2,
1H), 4.50 (d, J = 11.5 Hz, PhCH2, 1H), 4.60 (d,
J = 11.2 Hz, PhCH2, 1H), 4.61 (d, J = 8.3 Hz, H-12,
1H), 4.73 (d, J = 12.0 Hz, PhCH2, 1H), 4.74 (d,
J = 11.5 Hz, PhCH2, 1H), 5.48 (d, J = 3.4 Hz, H-42,
1H), 7.15–7.17 (m, Ar, 2H), 7.24–7.41 (m, Ar, 24H),
7.71–7.75 (m, Ar, 4H); 13C NMR (CDCl3, 400 MHz):
d 19.22, 20.86, 26.82, 63.12, 65.67, 65.69, 67.82, 69.26,
70.76, 71.90, 72.02, 72.76, 73.30, 73.44, 73.58, 77.12,
77.21, 80.51, 96.92, 101.44, 127.13, 127.31, 127.33,
127.35, 127.40, 127.69, 127.72, 127.78, 127.83, 128.00,
128.09, 128.16, 128.36, 128.39, 128.43, 129.42, 129.65,
132.71, 133.30, 135.87, 135.97, 137.17, 137.43, 137.65,
138.29, 169.98; MALDI-TOFMS m/z calcd for
[C58H64N6O10Si]Na+: 1055.4. Found 1055.4. ESIMS
m/z calcd for [C58H64N6O10Si]Na+: 1055.4351. Found
1055.4384.
26
Isomer (8b): Syrup; ½aꢀD ꢁ28.8 (c 1.0, CHCl3); 1H
NMR (CDCl3, 400 MHz): d 2.09 (s, Ac, 3H), 3.44 (dd,
J = 3.2, 10.2 Hz, H-3, 1H), 3.53 (dd, J = 6.8, 9.5 Hz,
H-6a, 1H), 3.61 (dd, J = 5.9, 9.5 Hz, H-6b, 1H), 3.70
(ddd, J = 7.6, 10.5, 14.4 Hz, H-2, 1H), 3.78 (t,
J = 6.6 Hz, H-5, 1H), 4.46 (d, J = 11.7 Hz, PhCH2,
1H), 4.49 (d, J = 11.2 Hz, PhCH2, 1H), 4.58 (d,
J = 11.7 Hz, PhCH2, 1H), 4.77 (d, J = 11.2 Hz, PhCH2,
1H), 4.97 (dd, J = 7.6, 52.0 Hz, H-1, 1H), 5.58 (t,
J = 3.2 Hz, H-4, 1H), 7.29–7.38 (m, Ar, 10H); 13C
NMR (CDCl3, 100 MHz): d 20.43, 62.14, 62.35, 64.50,
67.08, 71.65, 72.13, 72.18, 73.44, 76.46, 76.77, 106.47,
108.60, 127.64, 127.71, 127.78, 127.97, 128.13, 136.30,
136.87, 169.50; MALDI-TOFMS m/z calcd for
[C22H24FN3O5]Na+: 452.2. Found 452.2. Anal Calcd
for C22H24FN3O5: C, 61.53; H, 5.63; N, 9.78. Found:
C, 61.29; H, 5.57; N, 9.53.
3.15. tert-Butyldiphenylsilyl 4-acetyl-2-azido-3,6-di-O-
benzyl-2-deoxy-D-galactopyranosyl-(1!4)-2-azido-3,6-
di-O-benzyl-2-deoxy-b-D-galactopyranoside (9)
3.16. General procedure for deprotection of PFP group:
tert-Butyldiphenylsilyl 2-azido-3,6-di-O-benzyl-2-deoxy-
a-D-galactopyranosyl-(1!4)-2-azido-3,6-di-O-benzyl-2-
deoxy-b-D-galactopyranoside (10)
This compound was synthesized from 8b and 4a accord-
ing to the general procedure for glycosylation outlined
in Section 3.12 (80%, a:b = 96:4). a-Isomer (9a): Syrup;
23
½aꢀD +81.5 (c 1.1, CHCl3); 1H NMR (CDCl3, 400 MHz):
d 1.05 (s, tBu, 9H), 1.93 (s, Ac, 3H), 3.00–3.04 (m, H-31,
H-6a1, 2H), 3.09 (dd, J = 5.1, 8.8 Hz, H-6a2, 1H), 3.15–
To a solution of 5a (54.0 mg, 0.0474 mmol) in EtOH
(3.00 mL), pyridine (76.7 lL, 0.950 mmol) was added

A. Ishiwata et al. / Carbohydrate Research 341 (2006) 1557–1573
1569
at rt. The reaction mixture was stirred at 80 ꢁC for 88 h.
3.18. tert-Butyldiphenylsilyl 2-azido-3,6-di-O-benzyl-2-
After concentration in vacuo, azeotropic removal of ex-
cess pyridine and side product PFPOEt with toluene for
several times gave 10 as an amorphous solid (44.7 mg,
deoxy-a-D-galactopyranosyl-(1!4)-2-azido-3,6-di-
O-benzyl-2-deoxy-a-D-galactopyranosyl-(1!4)-2-azido-
3,6-di-O-benzyl-2-deoxy-b-D-galactopyranoside (11b)
26
95%); ½aꢀD +71.6 (c 1.0, CHCl3); 1H NMR (CDCl3,
t
400 MHz): d 1.12 (s, Bu, 9H), 2.98 (br s, OH, 1H),
This compound was synthesized from 11a according to
the general procedure for deprotection outlined in Sec-
tion 3.16 (99%). An amorphous solid; 1H NMR (CDCl3,
400 MHz): d 1.09 (s, tBu, 9H), 3.03–3.09 (m, H-31, H-61,
2H), 3.19–3.26 (m, H-61, H-62, H-63, 3H), 3.44 (dd,
J = 6.6, 9.8 Hz, H-62, 1H), 3.57–3.65 (m, H-21, H-23,
2H), 3.72–3.78 (m, H-22, H-51, 2H), 3.83 (t,
J = 8.8 Hz, H-63 1H), 3.89 (dd, J = 2.7, 10.5 Hz, H-32,
1H), 4.01 (dd, J = 2.4, 11.0 Hz, H-33, 1H), 4.04 (d,
J = 2.9 Hz, H-41, 1H), 4.14–4.17 (m, PhCH2, 3H),
4.22–4.28 (m, H-11, H-42, H-52, PhCH2, 4H), 4.34 (d,
J = 11.7 Hz, PhCH2, 1H), 4.36 (d, J = 2.4 Hz, H-43,
1H), 4.38–4.46 (m, H-53, PhCH2, 3H), 4.65 (d,
J = 12.0 Hz, PhCH2, 1H), 4.66 (d, J = 11.2 Hz, PhCH2,
1H), 4.73 (d, J = 12.9 Hz, PhCH2, 1H), 4.76 (d,
J = 12.9 Hz, PhCH2, 1H), 4.91 (d, J = 12.0 Hz, PhCH2,
1H), 5.01 (d, J = 3.9 Hz, H-13, 1H), 5.02 (d, J = 4.1 Hz,
H-12, 1H), 7.17–7.42 (m, Ar, 36H), 7.66–7.71 (m, Ar,
4H); MALDI-TOFMS m/z calcd for [C76H83N9O13Si]-
Na+: 1380.6. Found 1380.7.
3.07 (dd, J = 2.7, 10.2 Hz, H-31, 1H), 3.09 (dd,
J = 5.6, 9.3 Hz, H-6a1, 1H), 3.25 (dd, J = 5.6, 9.3 Hz,
H-6b1, 1H), 3.33 (dd, J = 4.4, 9.8 Hz, H-6a2, 1H), 3.52
(dd, J = 6.1, 9.5 Hz, H-6b2, 1H), 3.67 (dd, J = 7.6,
10.5 Hz, H-21, 1H), 3.77 (dd, J = 3.7, 10.7 Hz, H-22,
1H), 3.81 (t, J = 9.0 Hz, H-51, 1H), 4.04 (dd, J = 2.7,
9.8 Hz, H-32, 1H), 4.05 (d, J = 2.7 Hz, H-41, 1H),
4.26–4.29 (m, H-11, H-42, PhCH2, 3H), 4.34–4.38 (m,
H-52, PhCH2, 3H), 4.42 (d, J = 11.7 Hz, PhCH2, 1H),
4.51 (d, J = 12.4 Hz, PhCH2, 1H), 4.73 (d,
J = 12.7 Hz, PhCH2, 1H), 4.79 (dd, J = 11.2, 20.5 Hz,
PhCH2, 2H), 4.98 (d, J = 3.4 Hz, H-12, 1H), 7.21–7.48
(m, Ar, 26H), 7.68–7.73 (m, Ar, 4H); 13C NMR (CDCl3,
100 MHz): d 19.23, 26.84, 59.13, 65.87, 66.64, 68.32,
69.45, 71.31, 71.61, 72.02, 72.73, 73.32, 73.55, 75.51,
77.20, 78.67, 96.87, 99.11, 127.11, 127.35, 127.39,
127.65, 127.68, 127.82, 127.87, 127.99, 128.27, 128.33,
128.35, 128.49, 129.49, 129.68, 132.66, 133.28, 135.79,
135.92, 137.23, 137.42, 137.45, 137.47; MALDI-
TOFMS m/z calcd for [C59H62N6O9Si]Na+: 1013.4.
Found 1013.9. Anal Calcd for C59H62N6O9Si: C,
67.86; H, 6.30; N, 8.48. Found: C, 67.80; H, 6.20; N,
8.34.
3.19. tert-Butyldiphenylsilyl 2-azido-3,6-di-O-benzyl-2-
deoxy-4-O-pentafluoropropionyl-D-galactopyranosyl-
(1!4)-2-azido-3,6-di-O-benzyl-2-deoxy-a-D-galacto-
pyranosyl-(1!4)-2-azido-3,6-di-O-benzyl-2-deoxy-
a-D-galactopyranosyl-(1!4)-2-azido-3,6-di-O-benzyl-
2-deoxy-b-D-galactopyranoside (11c)
3.17. tert-Butyldiphenylsilyl 2-azido-3,6-di-O-benzyl-2-
deoxy-4-O-pentafluoropropionyl-D-galactopyranosyl-
(1!4)-2-azido-3,6-di-O-benzyl-2-deoxy-a-D-galacto-
pyranosyl-(1!4)-2-azido-3,6-di-O-benzyl-2-deoxy-
b-D-galactopyranoside (11A)
This compound was synthesized from 1b and 11b
according to the general procedure for glycosylation
outlined in Section 3.12 (76%, a:b = 95:5). A syrup;
1H NMR (CDCl3, 400 MHz): d 1.07 (s, tBu, 9H),
2.89 (dd, J = 5.4, 8.5 Hz, H-64, 1H), 2.99–3.08 (m,
H-31, H-61, H-63, H-64, 4H), 3.19–3.22 (m, H-61, H-
62, 2H), 3.28 (dd, J = 3.7, 10.7 Hz, H-24, 1H), 3.51–
3.59 (m, H-21, H-22, H-23, 3H), 3.70–3.89 (m, H-33,
H-51, H-62, H-63, PhCH2, 7H), 3.91 (dd, J = 2.9,
10.5 Hz, H-34, 1H), 3.99–4.02 (m, H-32, H-41, PhCH2,
3H), 4.10 (d, J = 12.0 Hz, PhCH2, 1H), 4.14 (d,
J = 12.0 Hz, PhCH2, 1H), 4.19 (d, J = 7.6 Hz, H-11,
1H), 4.24 (br s, H-43, 1H), 4.28–4.45 (m, H-42, H-52,
H-53, H-54, PhCH2, 8H), 4.52 (d, J = 12.2 Hz, PhCH2,
1H), 4.62 (d, J = 12.2 Hz, PhCH2, 1H), 4.68–4.73 (dm,
PhCH2, 2H), 4.80 (d, J = 3.7 Hz, H-14, 1H), 4.84 (d,
J = 12.2 Hz, PhCH2, 1H), 4.94–4.97 (m, H-12, PhCH2,
2H), 5.02 (d, J = 3.7 Hz, H-13, 1H), 5.76 (br s, H-44,
1H), 7.03–7.05 (m, Ar, 2H), 7.14–7.47 (m, Ar,
44H), 7.62–7.66 (m, Ar, 4H); MALDI-TOFMS m/z
calcd for [C99H103F5N12O18Si]Na+: 1893.7. Found
1893.5.
This compound was synthesized from 1b and 10 accord-
ing to the general procedure for glycosylation outlined
in Section 3.12 (80%, a:b = 95:5): Syrup; 1H NMR
t
(CDCl3, 400 MHz): d 1.08 (s, Bu, 9H), 2.96–3.08 (m,
H-31, H-61, H-63, 3H), 3.11–3.14 (m, H-62, H-63, 2H),
3.20 (dd, J = 5.6, 9.3 Hz, H-51, 1H), 3.32 (dd, J = 3.4,
10.5 Hz, H-23, 1H), 3.54–3.60 (m, H-21, H-22, 2H),
3.71–3.79 (m, H-61, H-62, 2H), 3.84 (d, J = 11.5 Hz,
PhCH2, 1H), 3.92 (d, J = 11.0 Hz, PhCH2, 1H), 3.92–
4.01 (m, H-32, H-33, H-41, PhCH2, 4H), 4.14 (d,
J = 12.0 Hz, PhCH2, 1H), 4.20 (d, J = 7.6 Hz, H-11,
1H), 4.29–4.47 (m, H-42, H-52, PhCH2, 6H), 4.54 (dd,
J = 6.1, 9.0 Hz, H-53, 1H), 4.62 (d, J = 12.2 Hz, PhCH2,
1H), 4.71–4.75 (m, PhCH2, 2H), 4.85 (d, J = 3.7 Hz,
H-13, 1H), 4.89 (d, J = 12.0 Hz, PhCH2, 1H), 4.97 (d,
J = 3.7 Hz, H-12, 1H), 5.78 (d, J = 1.7 Hz, H-43,
1H), 7.06–7.08 (m, Ar, 2H), 7.15–7.43 (m, Ar,
34H), 7.62–7.66 (m, Ar, 4H); MALDI-TOFMS m/z
calcd for [C79H82F5N9O14Si]Na+: 1526.6. Found
1527.4.

1570
A. Ishiwata et al. / Carbohydrate Research 341 (2006) 1557–1573
3.20. tert-Butyldiphenylsilyl 2-azido-3,6-di-O-benzyl-2-
deoxy-a-D-galactopyranosyl-(1!4)-2-azido-3,6-di-O-
benzyl-2-deoxy-a-D-galactopyranosyl-(1!4)-2-azido-
3,6-di-O-benzyl-2-deoxy-a-D-galactopyranosyl-(1!4)-
2-azido-3,6-di-O-benzyl-2-deoxy-b-D-galactopyranoside
(11d)
129.66, 132.63, 133.24, 135.80, 135.94, 136.45, 137.12,
137.27, 137.35, 137.43, 137.50, 137.66; MALDI-
TOFMS m/z calcd for [C119H124F5N15O22Si]Na+:
2260.9. Found 2261.1. ESIMS m/z calcd for [C119H124
-
F5N15O22Si]Na+: 2260.8632. Found 2260.8534.
3.22. tert-Butyldiphenylsilyl 2,3,4,6-tetra-O-acetyl-b-D-
glucopyranosyl-(1!3)-2-azido-6-O-benzyl-2-deoxy-4-O-
This compound was synthesized from 11c according to
the general procedure for deprotection outlined in Sec-
pentafluoropropionyl-D-galactopyranosyl-(1!4)-2-azido-
3,6-di-O-benzyl-2-deoxy-a-D-galactopyranosyl-(1!4)-2-
azido-3,6-di-O-benzyl-2-deoxy-b-D-galactopyranoside
(12)
1
tion 3.16 (99%): H NMR (CDCl3, 400 MHz): d 1.27
t
(s, Bu, 9H), 2.37 (br s, OH, 1H), 2.99–3.12 (m, H-3,
H-6, 4H), 3.22–3.24 (m, H-6, 2H), 3.36 (dd, J = 6.4,
9.0 Hz, H-6, 1H), 3.58–3.62 (m, H-2, 3H), 3.71 (dd,
J = 3.4, 10.5 Hz, H-2, 1H), 3.74–3.93 (m, H-3, H-5, H-
6, 5H), 3.90–4.10 (m, PhCH2, 2H), 4.03–4.23 (m, H-1,
H-4, H-5, PhCH2, 7H), 4.31–4.45 (m, H-4, H-5, PhCH2,
7H), 4.55 (d, J = 12.0 Hz, PhCH2, 1H), 4.62–4.76 (m,
PhCH2, 4H), 4.86 (d, J = 12.2 Hz, PhCH2, 1H), 4.97–
5.00 (m, H-1, PhCH2, 3H), 5.07 (d, J = 3.4 Hz, H-1,
1H), 7.16–7.50 (m, Ar, 46H), 7.66–7.70 (m, Ar, 4H);
MALDI-TOFMS m/z calcd for [C96H104N12O17Si]Na+:
1747.7. Found 1747.0.
This compound was synthesized from 7b and 10 accord-
ing to the general procedure for glycosylation (Section
3.12) except that 2 equiv of donor was used and that
the mixture was stirred at 60 ꢁC (72%, a:b = 83:17). a-
24
Isomer (12a): Amorphous solid; ½aꢀD +64.9 (c 1.1,
1
t
CHCl3); H NMR (CDCl3, 400 MHz): d 1.14 (s, Bu,
9H), 2.03 (s, Ac, 3H), 2.04 (s, Ac, 3H), 2.05 (s, Ac,
3H), 2.07 (s, Ac, 3H), 3.09–3.14 (m, H-3Gal1, H-6Gal1
,
,
H-6aGal3, 4H), 3.24 (dd, J = 5.4, 8.3 Hz, H-6aGal2
1H), 3.29 (dd, J = 5.6, 9.3 Hz, H-6bGal3, 1H), 3.43 (dd,
3.21. tert-Butyldiphenylsilyl 2-azido-3,6-di-O-benzyl-2-
deoxy-4-O-pentafluoropropionyl-D-galactopyranosyl-
(1!4)-2-azido-3,6-di-O-benzyl-2-deoxy-a-D-galacto-
pyranosyl-(1!4)-2-azido-3,6-di-O-benzyl-2-deoxy-
a-D-galactopyranosyl-(1!4)-2-azido-3,6-di-O-benzyl-
2-deoxy-a-D-galactopyranosyl-(1!4)-2-azido-3,6-di-
O-benzyl-2-deoxy-b-D-galactopyranoside (11e)
J = 3.7, 10.7 Hz, H-2Gal3, 1H), 3.62–3.68 (m, H-2Gal1
H-22, 2H), 3.76–3.81 (m, H-5Gal1, H-5Glc, H-6bGal2
3H), 4.04–4.28 (m, H-1Gal1, H-3Gal2, H-3Gal3, H-4Gal1
,
,
,
H-6aGlc, PhCH2, 9H), 4.36–4.39 (m, H-4Gal2, PhCH2,
2H), 4.40–4.55 (m, H-5Gal2, H-5Gal3, H-6bGlc, PhCH2,
5H), 4.66 (d, J = 12.0 Hz, PhCH2, 1H), 4.80 (d,
J = 8.4 Hz, H-1Glc, 1H), 4.81 (d, J = 10.7 Hz, PhCH2,
1H), 4.92–4.97 (m, H-2Glc, PhCH2, 2H), 5.01 (d,
This compound was synthesized from 1b and 11d
J = 3.7 Hz, H-1Gal3, 1H), 5.08 (d, J = 3.2 Hz, H-1Gal2
1H), 5.12 (t, J = 9.8 Hz, H-4Glc
1H), 5.21 (t,
J = 9.5 Hz, H-3Glc, 1H), 5.83 (d, J = 2.7 Hz, H-4Gal3
,
according to the general procedure for glycosylation
,
24
outlined in Section 3.12 (76%, a:b = 95:5): Syrup; ½aꢀD
,
1
+150.0 (c 1.0, CHCl3); H NMR (CDCl3, 400 MHz): d
1.09 (s, Bu, 9H), 2.89–2.97 (m, H-6, 2H), 3.02–3.21
1H), 7.18–7.45 (m, Ar, 31H), 7.70–7.73 (m, Ar, 4H);
13C NMR (CDCl3, 100 MHz): d 19.17, 20.45, 20.58,
20.61, 26.76, 59.54, 59.70, 61.47, 65.86, 65.90, 66.61,
66.85, 66.96, 67.93, 68.97, 71.19, 71.58, 71.73, 71.77,
72.04, 72.33, 72.47, 72.83, 73.19, 73.26, 73.32, 74.15,
74.81, 75.19, 77.20, 78.77, 96.81, 98.11, 99.08, 101.17,
127.05, 127.07, 127.13, 127.37, 127.70, 127.77, 127.84,
127.92, 128.16, 128.32, 128.34, 128.40, 128.49, 129.46,
129.67, 132.54, 133.14, 135.77, 135.89, 137.05, 137.41,
137.43, 156.28, 168.90, 169.07, 170.11, 170.58; MAL-
DI-TOFMS m/z calcd for [C86H94F5N9O23Si]Na+:
1766.6. Found 1766.3. Anal Calcd for C86H94F5N9O23-
Si: C, 59.20; H, 5.43; N, 7.22. Found: C, 59.05; H,
t
(m, H-3, H-6, 4H), 3.23–3.25 (m, H-6, 2H), 3.28 (dd,
J = 3.7, 10.7, H-25, 1H), 3.53 (dd, J = 3.4, 10.7 Hz, H-
2, 1H), 3.57–3.68 (m, H-2, 3H), 3.70–4.03 (m, H-3, H-
4, H-5, H-6, PhCH2, 13H), 4.11–4.18 (m, PhCH2, 2H),
4.21–4.25 (m, H-1, H-4, H-5, 3H), 4.27–4.57 (m, H-4,
H-5, PhCH2, 13H), 4.63 (d, J = 12.2 Hz, PhCH2, 1H),
4.74 (d, J = 12.7 Hz, PhCH2, 1H), 4.75 (d,
J = 10.2 Hz, PhCH2, 1H), 4.81 (d, J = 3.4 Hz, H-15,
1H), 4.86 (d, J = 12.2 Hz, PhCH2, 1H), 4.93–4.99 (m,
H-1, PhCH2, 3H), 5.01 (d, J = 3.7 Hz, H-1, 1H), 5.05
(d, J = 3.4 Hz, H-1, 1H), 5.79 (br s, H-45, 1H), 7.07–
7.48 (m, Ar, 56H), 7.66–7.69 (m, Ar, 4H); 13C NMR
(CDCl3, 100 MHz): d 19.21, 26.80, 59.49, 59.70, 60.07,
65.80, 66.43, 66.69, 68.92, 69.14, 70.94, 71.38, 71.51,
71.73, 71.84, 72.02, 72.14, 72.30, 72.64, 72.98, 73.18,
73.34, 74.09, 75.23, 76.24, 77.21, 78.66, 96.85, 98.19,
98.73, 99.06, 125.22, 126.58, 126.61, 126.93, 127.08,
127.14, 127.38, 127.49, 127.58, 127.68, 127.74, 127.78,
127.82, 127.87, 128.06, 128.09, 128.15, 128.20, 128.25,
128.29, 128.35, 128.39, 128.42, 128.50, 128.96, 129.45,
25
5.22; N, 7.06. b-Isomer (12b): Amorphous solid; ½aꢀD
1
+41.2 (c 1.1, CHCl3); H NMR (CDCl3, 400 MHz): d
1.13 (s, Bu, 9H), 2.03 (s, Ac, 3H), 2.04 (s, Ac, 3H),
t
2.05 (s, Ac, 3H), 2.06 (s, Ac, 3H), 3.04–3.10 (m, H-
3Gal1, H-6aGal2, 2H), 3.19–3.26 (m, H-6aGal1, H-6bGal2
,
2H), 3.31–3.37 (m, H-6aGal3, H-6bGal1, 2H), 3.41 (dd,
J = 3.4, 10.2 Hz, H-3Gal3, 1H), 3.47–3.60 (m, H-2Gal3
,
,
H-5Gal1, H-6bGal3, 3H), 3.66–3.71 (m, H-2Gal1, H-5Glc
2H), 3.79 (t, H-5Gal2, 1H), 3.91 (dd, J = 3.4, 10.7 Hz,

A. Ishiwata et al. / Carbohydrate Research 341 (2006) 1557–1573
1571
H-2Gal2, 1H), 4.04 (d, J = 2.7 Hz, H-4Gal1, 1H), 4.06–
4.19 (m, H-1Gal1, H-3Gal2, H-6aGlc, 3H), 4.21–4.33 (m,
H-6bGlc, PhCH2, 5H), 4.39 (d, J = 11.7 Hz, PhCH2,
1H), 4.45–4.52 (m, H-4Gal2, H-5Gal3, PhCH2, 3H), 4.66
127.37, 127.42, 127.55, 127.57, 127.65, 127.71, 127.76,
127.80, 127.83, 127.98, 128.12, 128.18, 128.29, 128.33,
128.38, 128.42, 128.93, 129.44, 129.66, 132.58, 133.20,
135.79, 135.93, 137.18, 137.24, 137.42, 137.44, 137.74,
169.18, 169.23, 170.06, 170.52; MALDI-TOFMS m/z
calcd for [C83H95N9O22Si]Na+: 1620.6. Found 1621.1.
ESIMS m/z calcd for [C83H95N9O22Si]Na+: 1620.6259.
Found 1620.6249.
(d, J = 7.8 Hz, H-1Gal3, 1H), 4.72–4.82 (m, H-1Glc
,
PhCH2, 3H), 4.86–4.93 (m, H-2Glc, PhCH2, 2H), 5.01
(d, J = 3.4 Hz, H-1Gal3, 1H), 5.11 (t, J = 9.5 Hz, H-
4Glc, 1H), 5.22 (t, J = 9.5 Hz, H-3Glc, 1H), 5.57 (d,
J = 3.2 Hz, H-4Gal3, 1H), 7.17–7.50 (m, Ar, 30H),
7.69–7.74 (m, Ar, 5H); 13C NMR (CDCl3, 100 MHz):
d 19.21, 20.43, 20.54, 20.61, 26.84, 59.84, 61.27, 63.34,
65.88, 66.70, 66.92, 68.02, 68.10, 69.15, 70.91, 70.94,
71.02, 71.14, 71.28, 71.59, 71.78, 71.86, 72.27, 72.52,
72.71, 72.97, 73.37, 73.72, 76.58, 76.88, 77.21, 78.01,
96.82, 98.78, 100.98, 101.20, 125.19, 126.97, 127.07,
127.12, 127.17, 127.29, 127.36, 127.41, 127.47, 127.54,
127.59, 127.64, 127.69, 127.73, 127.75, 127.83, 127.87,
127.91, 127.94, 127.97, 128.06, 128.11, 128.14, 128.18,
128.23, 128.30, 128.34, 128.36, 128.40, 128.45, 128.50,
128.58, 128.77, 128.92, 129.45, 129.65, 132.63, 132.65,
133.33, 135.77, 135.89, 136.94, 137.35, 137.43, 137.46,
137.49, 138.13, 156.54, 168.78, 169.10, 170.10, 170.54;
MALDI-TOFMS m/z calcd for [C86H94F5N9O23Si]Na+:
1766.6. Found 1766.4. Anal Calcd for C86H94F5N9O23Si:
C, 59.20; H, 5.43; N, 7.22. Found: C, 59.37; H, 5.23; N,
7.17.
3.24. tert-Butyldiphenylsilyl 2-azido-3,6-di-O-benzyl-2-
deoxy-4-O-pentafluoropropionyl-D-galactopyranosyl-
(1!4)-[2,3,4,6-tetra-O-acetyl-b-D-glucopyranosyl-
(1!3)]-2-azido-6-O-benzyl-2-deoxy-a-D-galactopyran-
osyl-(1!4)-2-azido-3,6-di-O-benzyl-2-deoxy-a-D-galacto-
pyranosyl-(1!4)-2-azido-3,6-di-O-benzyl-2-deoxy-b-D-
galactopyranoside (14a)
This compound was synthesized from 1b and 13 accord-
ing to the general procedure for glycosylation (Section
3.12) except that 2 equiv of donor was used and the mix-
ture was stirred at 60 ꢁC for 84 h (96%, a:b = >95:5).
23
1
a-Isomer (14a): Syrup; ½aꢀD +216.6 (c 1.0, CHCl3); H
t
NMR (CDCl3, 400 MHz): d 1.09 (s, Bu, 9H), 1.85 (s,
Ac, 3H), 2.01 (s, Ac, 3H), 2.05 (s, Ac, 3H), 2.07 (s,
Ac, 3H), 3.03–3.11 (m, H-2Gal4, H-3Gal1, H-6Gal1, H-
6Gal2, 4H), 3.24–3.28 (m, H-6Gal1, H-6Gal3, 2H), 3.35
(dd, J = 3.7, 11.0 Hz, H-2Gal2, 1H), 3.41 (t, J = 9.0 Hz,
H-6Gal4, 1H), 3.48 (t, J = 9.5 Hz, H-6Gal2, 1H), 3.58–
3.79 (m, H-2Gal1, H-2Gal3, H-5Gal1, H-6Gal3, H-6Gal4
,
3.23. tert-Butyldiphenylsilyl 2,3,4,6-tetra-O-acetyl-b-D-
glucopyranosyl-(1!3)-2-azido-6-O-benzyl-2-deoxy-a-D-
galactopyranosyl-(1!4)-2-azido-3,6-di-O-benzyl-2-
deoxy-a-D-galactopyranosyl-(1!4)-2-azido-3,6-di-O-
benzyl-2-deoxy-b-D-galactopyranoside (13)
PhCH2, 7H), 3.93 (dd, J = 3.1, 10.7 Hz, H-3Gal2, 1H),
3.98 (dd, J = 2.9, 10.7 Hz, H-3Gal4, 1H), 4.04–4.10 (m,
H-3Gal3, H-4Gal1, 2H), 4.22 (d, J = 7.6 Hz, H-1Gal1
,
1H), 4.27–4.35 (m, H-4Gal2, H-5Gal2, H-6Glc, PhCH2,
5H), 4.41–4.48 (m, H-4Gal3, H-5Gal3, PhCH2, 6H), 4.51
(d, J = 10.7 Hz, PhCH2, 1H), 4.61 (d, J = 12.2 Hz,
PhCH2, 1H), 4.71–4.81 (m, H-1Gal4, H-1Glc, PhCH2,
4H), 4.87–4.89 (m, H-5Gal4, PhCH2, 2H), 4.94 (d,
This compound was synthesized from 12a according to
the general procedure for deprotection outlined in Sec-
24
tion 3.16 (92%). Amorphous solid; ½aꢀD +74.6 (c 1.0,
1
t
J = 12.2 Hz, PhCH2, 1H), 5.05 (d, J = 3.7 Hz, H-1Gal3
,
CHCl3); H NMR (CDCl3, 400 MHz): d 1.10 (s, Bu,
1H), 5.08 (d, J = 3.7 Hz, H-1Gal2, 1H), 5.21–5.23 (m,
H-2Glc, H-3Glc, H-4Glc, 3H), 6.04 (br s, H-4Gal4, 1H),
7.14–7.46 (m, Ar, 40H), 7.65–7.69 (m, Ar, 5H); 13C
NMR (CDCl3, 100 MHz): d 19.19, 20.43, 20.61, 20.66,
20.74, 26.76, 59.18, 59.43, 60.25, 61.41, 65.62, 65.84,
66.09, 66.27, 66.37, 66.70, 68.04, 68.61, 69.01, 71.17,
71.32, 71.40, 71.53, 71.64, 71.89, 71.93, 72.53, 72.60,
72.85, 73.13, 73.25, 73.31, 73.56, 74.86, 76.61, 77.20,
78.65, 96.83, 98.55, 99.08, 102.47, 127.05, 127.07,
127.10, 127.37, 127.56, 127.68, 127.78, 127.79, 127.82,
127.84, 127.94, 128.06, 128.12, 128.15, 128.24, 128.30,
128.37, 128.39, 128.42, 128.47, 128.51, 129.46, 129.67,
132.58, 133.16, 135.79, 135.93, 136.75, 136.83, 137.11,
137.23, 137.42, 137.44, 137.48, 157.33, 169.21, 170.01,
170.28; MALDI-TOFMS m/z calcd for [C106H115F5-
N12O27Si]Na+: 2133.8. Found 2133.8. Anal Calcd for
9H), 2.02 (s, Ac, 3H), 2.03 (s, Ac, 3H), 2.05 (s, Ac,
3H), 2.06 (s, Ac, 3H), 3.03–3.09 (m, H-3Gal1, H-6aGal2
,
2H), 3.25–3.30 (m, H-6bGal2, H-6Gal3, 3H), 3.55–3.67
(m, H-2Gal1, H-2Gal2, H-2Gal3, H-6aGal1, 4H), 3.71–3.77
(m, H-5Gal2, H-5Glc, H-6bGal1, 3H), 4.00–4.13 (m, H-
3Gal2, H-3Gal3, H-4Gal1, 3H), 4.17–4.26 (m, H-1Gal1, H-
4Gal2, H-6Glc, PhCH2, 8H), 4.32–4.46 (m, H-4Gal3, H-
5Gal1, H-5Gal3, PhCH2, 6H), 4.62 (d, J = 12.2 Hz,
PhCH2, 1H), 4.75 (d, J = 12.9 Hz, PhCH2, 1H), 4.78
(d, J = 7.8 Hz, H-1Glc, 1H), 4.94 (d, J = 12.2 Hz,
PhCH2, 1H), 5.03–5.12 (m, H-1Gal2, H-1Gal3, H-2Glc
,
H-4Glc, 4H), 5.21 (t, J = 9.3 Hz, H-3Glc, 1H), 7.19–7.45
(m, Ar, 31H), 7.67–7.70 (m, Ar, 4H); 13C NMR (CDCl3,
100 MHz): d 19.19, 20.62, 20.66, 26.77, 58.79, 59.55,
61.67, 65.81, 66.71, 67.06, 68.04, 68.08, 68.56, 69.06,
70.99, 71.23, 71.49, 71.62, 71.89, 71.99, 72.55, 72.80,
73.14, 73.27, 73.30, 74.64, 77.20, 78.33, 78.60, 78.67,
96.82, 98.61, 98.98, 101.28, 125.19, 127.07, 127.10,
C
106H115F5N12O27Si: C, 60.28; H, 5.49; N, 7.96. Found:
C, 60.29; H, 5.25; N, 7.77.

1572
A. Ishiwata et al. / Carbohydrate Research 341 (2006) 1557–1573
25
3.25. tert-Butyldiphenylsilyl 2-azido-3,6-di-O-benzyl-2-
deoxy-a-D-galactopyranosyl-(1!4)-[2,3,4,6-tetra-O-acet-
yl-b-D-glucopyranosyl-(1!3)]-2-azido-6-O-benzyl-2-
deoxy-a-D-galactopyranosyl-(1!4)-2-azido-3,6-di-O-
benzyl-2-deoxy-a-D-galactopyranosyl-(1!4)-2-azido-3,
6-di-O-benzyl-2-deoxy-b-D-galactopyranoside (14b)
(88%, a:b = >95:5). Compound 14c: Syrup; ½aꢀD
1
+141.3 (c 1.0, CHCl3); H NMR (CDCl3, 400 MHz): d
1.09 (s, Bu, 9H), 1.80 (s, Ac, 3H), 2.04 (s, Ac, 3H),
t
2.07 (s, Ac, 3H), 2.09 (s, Ac, 3H), 2.98–3.11 (m, H-
3Gal1, H-6, 3H), 3.13–3.20 (m, H-2Gal5, H-6, 3H), 3.21–
3.28 (m, H-6, 2H), 3.32–3.38 (m, H-1, H-2, 2H), 3.52–
3.84 (m, H-2, H-5, H-6, 7H), 3.86–3.97 (m, H-3, PhCH2,
5H), 4.00–4.09 (m, H-3, H-4, H-6, PhCH2, 5H), 4.09–
This compound was synthesized from 14a according to
the general procedure for deprotection outlined in Sec-
4.15 (m, PhCH2, 2H), 4.21 (d, J = 7.8 Hz, H-1Gal1
,
25
tion 3.16 (quantitative): Amorphous solid; ½aꢀD +136.0
1H), 4.31–4.36 (m, H-5Glc, H-6Glc, PhCH2, 4H), 4.39–
4.49 (m, H-4, H-5, PhCH2, 7H), 4.52–4.64 (m, H-5,
PhCH2, 4H), 4.69–4.79 (m, H-1Gal5, H-1Glc, PhCH2,
4H), 4.89–4.92 (m, PhCH2, 3H), 4.94 (d, J = 3.4 Hz,
H-1, 1H), 5.01 (d, J = 12.0 Hz, PhCH2, 1H), 5.05 (d,
1
(c 1.0, CHCl3); H NMR (CDCl3, 400 MHz): d 1.10
t
(s, Bu, 9H), 1.82 (s, Ac, 3H), 1.98 (s, Ac, 3H), 2.04 (s,
Ac, 3H), 2.07 (s, Ac, 3H), 3.03–3.09 (m, H-3Gal1, H-
6Gal1, OH, 3H), 3.17 (dd, J = 5.1, 8.5 Hz, H-6Gal2
,
1H), 3.25–3.29 (m, H-6Gal1, H-6Gal3, 2H), 3.43 (dd,
J = 3.7 Hz, H-1Gal1, 1H), 5.09 (d, J = 3.9 Hz, H-1Gal1
,
J = 3.7, 11.0 Hz, H-2Gal2, 1H), 3.51 (dd, J = 3.7,
1H), 5.22–5.32 (m, H-2Glc, H-3Glc, H-4Glc, 3H), 5.78
(d, J = 2.2 Hz, H-4Gal5, 1H), 7.09–7.52 (m, Ar, 51H),
7.66–7.69 (m, Ar, 4H); 13C NMR (CDCl3, 100 MHz):
d 19.20, 20.36, 20.60, 20.66, 20.75, 26.78, 59.40, 60.24,
61.37, 65.84, 66.33, 66.48, 66.53, 66.72, 67.98, 68.72,
68.74, 69.03, 71.00, 71.22, 71.29, 71.48, 71.50, 71.56,
71.93, 72.43, 72.55, 72.76, 72.78, 73.21, 73.25, 73.33,
74.09, 74.56, 75.02, 76.93, 77.21, 78.67, 96.84, 97.45,
98.14, 98.52, 99.08, 102.62, 125.21, 127.05, 127.08,
127.10, 127.21, 127.23, 127.38, 127.53, 127.66, 127.69,
127.71, 127.79, 127.81, 127.84, 128.06, 128.12, 128.15,
128.17, 128.25, 128.26, 128.29, 128.38, 128.48, 128.52,
128.94, 129.47, 129.68, 132.60, 133.17, 135.80, 135.94,
136.48, 137.09, 137.12, 137.19, 137.23, 137.43, 137.47,
137.62, 137.69, 169.24, 170.01, 170.36; MALDI-
TOFMS m/z calcd for [C126H136F5N15O31Si]Na+:
10.5 Hz, H-2Gal4, 1H), 3.55–3.81 (m, H-2Gal1, H-2Gal3
H-5Gal1, H-5Glc, H-6Gal3, 6H), 3.87–3.97 (m, H-3Gal2
H-3Gal4, H-6Gal4, PhCH2, 5H), 4.03–4.07 (m, H-3Gal3
,
,
,
H-4Gal1, PhCH2, 3H), 4.11–4.18 (m, PhCH2, 2H), 4.22
(d, J = 7.6 Hz, H-1Gal1, 1H), 4.25–4.26 (m, H-6Glc
2H), 4.32–4.46 (m, H-4Gal2, H-4Gal3, H-4Gal4, H-5Gal2
H-5Gal3, PhCH2, 7H), 4.55–4.80 (m, H-1Glc, H-5Gal4
,
,
,
PhCH2, 7H), 4.87 (d, J = 12.2 Hz, PhCH2, 1H), 4.92–
4.95 (m, H-1Gal4, PhCH2, 2H), 5.05 (d, J = 3.7 Hz, H-
1Gal3, 1H), 5.12 (d, J = 3.7 Hz, H-1Gal2, 1H), 5.17–5.24
(m, H-2Glc, H-3Glc, H-4Glc, 3H), 7.15–7.46 (m, Ar,
40H), 7.66–7.69 (m, Ar, 5H); 13C NMR (CDCl3,
100 MHz): d 19.17, 20.38, 20.61, 20.66, 20.70, 26.75,
59.07, 59.38, 60.27, 61.51, 65.76, 65.81, 66.20, 66.42,
66.70, 67.91, 68.16, 68.51, 68.82, 69.02, 71.08, 71.22,
71.51, 71.56, 71.65, 71.88, 72.53, 72.75, 72.92, 73.22,
73.30, 73.49, 74.67, 75.37, 76.84, 77.21, 78.62, 96.82,
97.44, 98.55, 99.05, 102.49, 127.06, 127.08, 127.15,
127.25, 127.35, 127.38, 127.65, 127.68, 127.77, 127.81,
127.85, 128.05, 128.08, 128.12, 128.27, 128.31, 128.34,
128.38, 128.48, 128.59, 129.44, 129.66, 132.57, 133.15,
135.77, 135.91, 137.11, 137.17, 137.34, 137.39, 137.44,
138.27, 169.12, 169.20, 170.05, 170.39; MALDI-
TOFMS m/z calcd for [C103H116N12O26Si]Na+: 1987.8.
Found 1988.4. ESIMS m/z calcd for [C103H116N12O26-
Si]Na+: 1987.7791. Found 1987.7720.
2500.9. Found 2501.5. ESIMS m/z calcd for [C126H136
-
F5N15O31Si]Na+: 2500.9114. Found 2500.9196.
3.27. tert-Butyldiphenylsilyl 2-acetamido-2-deoxy-a-D-
galactopyranosyl-(1!4)-2-acetamido-2-deoxy-a-D-galac-
topyranosyl-(1!4)-[(b-D-glucopyranosyl)-(1!3)]-(2-acet-
amido-2-deoxy-a-D-galactopyranosyl)-(1!4)-(2-acetam-
ido-2-deoxy-a-D-galactopyranosyl)-(1!4)-2-acetamido-
2-deoxy-b-D-galactopyranoside (15)
To a solution of 14c (11.0 mg, 4.44 lmol) in CH3OH/
i-PrOH (2.5 mL, 4:1), 1 M solution of NaOCH3
(50 lL) was added at rt. After stirring for 2 h at the same
temperature, Amberlist H+ resin was added to the mix-
ture to quench excess NaOCH3. The resin was filtered
and the solution was concentrated. The crude mixture
was then dissolved in CH3OH (2 mL) and diisopropyl-
ethylamine (2.0 lL) was added at rt under an Ar atmo-
sphere. The solution was stirred with Pd(OH)2/C (20%,
5.5 mg) under a hydrogen atmosphere at rt for 1 h. After
the atmosphere was exchanged to Ar, the catalyst was
filtered off through Celite and concentrated to the half
volume. To the solution, Ac2O (50 lL) was added at
rt, and the mixture was stirred for 30 min at the same
temperature. The mixture was concentrated in vacuo
3.26. tert-Butyldiphenylsilyl 2-azido-3,6-di-O-benzyl-2-
deoxy-4-O-pentafluoropropionyl-D-galactopyranosyl-
(1!4)-2-azido-3,6-di-O-benzyl-2-deoxy-a-D-galactopyr-
anosyl-(1!4)-[2,3,4,6-tetra-O-acetyl-b-D-glucopyran-
osyl-(1!3)]-2-azido-6-O-benzyl-2-deoxy-a-D-galactopyr-
anosyl-(1!4)-2-azido-3,6-di-O-benzyl-2-deoxy-a-D-
galactopyranosyl-(1!4)-2-azido-3,6-di-O-benzyl-2-
deoxy-b-D-galactopyranoside (14c)
This compound was synthesized from 1b and 14B
according to the general procedure for glycosylation
(Section 3.12) except that 2 equiv of donor was used
and that the mixture was stirred at 60 ꢁC for 84 h

A. Ishiwata et al. / Carbohydrate Research 341 (2006) 1557–1573
1573
Dell, A.; Wren, B. W.; Aebi, M. Science 2002, 298, 1790–
1793.
5. Young, N. M.; Brisson, J.-R.; Kelly, J.; Watson, D. C.;
Tessier, L.; Lanthier, P. H.; Jarrell, H. C.; Cadotte, N.;
Michael, F. St.; Aberg, E.; Szymanski, C. M. J. Biol.
Chem. 2002, 227, 42530–42539.
6. Szymanski, C. M.; Logan, S. M.; Linton, D.; Wren, B. W.
Trends Microbiol. 2003, 11, 233–238.
7. Szymanski, C. M.; Burr, D. H.; Guerry, P. Infect. Immun.
2002, 70, 2242–2244.
8. van Vliet, A. H. M.; Ketley, J. M. J. Appl. Microbiol. 2001,
90, 45S–56S.
9. Nachamkin, I.; Allos, B. M.; Ho, T. Clin. Microbiol. Rev.
1998, 11, 555–567.
10. (a) Glover, K. J.; Weerapana, E.; Imperiali, B. Proc. Natl.
Acad. Sci. U.S.A. 2005, 102, 14255–14259; (b) Weerapana,
E.; Glover, K. J.; Chen, M. M.; Imperiali, B. J. Am. Chem.
Soc. 2005, 127, 13766–13767.
11. Arsequell, G.; Valencia, G. Tetrahedron: Asymmetry 1997,
8, 2839–2876.
and diluted in CHCl3/CH3OH/H2O (5 mL, 2:2:1). The
solution was stirred with Pd(OH)2/C (20%, 5.0 mg)
under a hydrogen atmosphere at rt for 48 h. After
exchanging to an Ar atmosphere, the catalyst was
filtered through Celite and concentrated. To the solution
of the crude mixture in CH3OH (2 mL), Ac2O (100 lL)
was added at rt, and the mixture was stirred for 12 h at
the same temperature. Ac2O (100 lL) and NaHCO3
(50.0 mg) were added to the mixture. The mixture was
concentrated in vacuo and diluted in CHCl3/CH3OH/
H2O (5 mL, 2:2:1). The solution was stirred with
Pd(OH)2/C (20%, 5.0 mg) under hydrogen atmosphere
at rt for 24 h. After exchanging to an Ar atmosphere,
the catalyst was filtered through Celite and concen-
trated. The residue was purified by reversed phase col-
umn chromatography (Sep-Pac, C18) using gradient
solvent system (H2O–MeOH, 1:0 to 0:1) to give the title
compound as an amorphous solid (2.8 mg, 44% in four
steps from 14c); 1H NMR (CD3OD/D2O, at 50 ꢁC,
12. Recent review for the synthesis of 1,2-cis glycoside, see:
Demchenko, A. V. Synlett 2003, 1225–1240.
13. Lemieux, R. U.; Ratcliffe, M. M. Can. J. Chem. 1979, 57,
1244–1251.
t
400 MHz): d 1.01 (s, Bu, 9H), 1.88 (s, AcNH, 3H),
14. Imamura, A.; Ando, H.; Korogi, S.; Tanabe, G.; Murao-
ka, O.; Ishida, H.; Kiso, M. Tetrahedron Lett. 2003, 44,
6725–6727.
15. Takatani, M.; Matsuo, I.; Ito, Y. Carbohydr. Res. 2003,
338, 1073–1081.
16. (a) Deslongchamps, P. Stereoelectronic Effect in Organic
Chemistry; Pergamon Press: Oxford, 1983; (b) Juaristi, E.;
Cuevas, G. The Anomeric Effect; CRC Press: Boca Raton,
1995; (c) Ayala, L.; Lucero, C. G.; Romero, J. A. C.;
Tabacco, S. A.; Woerpel, K. A. J. Am. Chem. Soc. 2003,
125, 15521–15528.
17. Nakahara, Y.; Iijima, H.; Shibayama, S.; Ogawa, T.
Carbohydr. Res. 1991, 216, 211–225.
18. (a) Liotta, L. J.; Ganem, B. Tetrahedron Lett. 1989, 36,
4759–4762; (b) Hung, S. C.; Shanker, R.; Chi, F. C.;
Chang, S. W.; Lee, J. C.; Wang, C. C.; Wen, Y. S. J. Am.
Chem. Soc. 2001, 123, 3153–3154.
2.03 (s, AcNH · 2, 6H), 2.047 (s, AcNH, 3H), 2.049 (s,
AcNH, 3H), 3.25–3.90 (m, 16H), 3.92–4.02 (m, H-
3Gal4, H-4Gal1, H-4Gal4, 3H), 4.06–4.16 (m, H-1Gal1, H-
3Gal2, H-3Gal3, H-3Gal5, H-4Gal13, H-4Gal5, 6H), 4.24–
4.36 (m, H-2Gal3, H-2Gal4, H-2Gal5, H-4Gal2, 4H), 4.30–
4.54 (m, 5H), 4.52 (d, J = 7.2 Hz, H-1Glc, 1H), 4.54–
4.58 (m, H-2Gal2, 1H), 4.62 (d, J = 8.0 Hz, H-1Gal1
1H), 5.01 (d, J = 4.0 Hz, H-1Gal2, 1H), 5.02 (d, J =
,
4.0 Hz, H-1Gal3, 1H), 5.04 (d, J = 4.0 Hz, H-1Gal4
,
1H), 5.12 (d, J = 4.0 Hz, H-1Gal1, 1H), 7.38–7.74 (m,
TBPS, 10H); MALDI-TOFMS m/z calcd for [C62H95-
N5O31Si]Na+: 1456.6. Found 1457.5. ESIMS m/z calcd
for [C62H95N5O31Si]Na+: 1456.5678. Found 1456.5620.
19. Garegg, P. J.; Hultberg, H.; Wallin, S. Carbohydr. Res.
1982, 108, 97–101.
Acknowledgments
20. (a) Nicolaou, K. C.; Seitz, S. P.; Pavia, M. R.; Petasis, N.
A. J. Org. Chem. 1979, 44, 4011–4013; (b) Nicolaou, K.
C.; Seitz, S. P.; Pavia, M. R. J. Am. Chem. Soc. 1981, 103,
1222–1224.
21. (a) Rosenbrook, W., Jr.; Riley, D. A.; Lartey, P. A.
Tetrahedron Lett. 1985, 26, 3–4; (b) Posner, G. H.; Haines,
S. H. Tetrahedron Lett. 1985, 26, 5–8.
Financial support from a Grant-in-Aid for Creative
Scientific Research from the Japan Society for the
Promotion of Science (Grant No. 17G4S0420) is
acknowledged. The authors thank Ms. Akemi Taka-
hashi for technical assistance.
22. Mukaiyama, T.; Murai, Y.; Shoda, S. Chem. Lett. 1981,
431–432.
References
23. (a) Matsumoto, T.; Maeta, H.; Suzuki, K.; Tsuchihashi,
G. Tetrahedron Lett. 1988, 29, 3567–3570; (b) Matsumoto,
T.; Maeta, H.; Suzuki, K.; Tsuchihashi, G. Tetrahedron
Lett. 1988, 29, 3571–3574; (c) Suzuki, K.; Maeta, H.;
Matsumoto, T. Tetrahedron Lett. 1989, 30, 4853–4856; (d)
Suzuki, K.; Maeta, H.; Suzuki, T.; Matsumoto, T.
Tetrahedron 1989, 30, 6879–6882.
24. Demchenko, A. V.; Rousson, E.; Boons, G. B. Tetra-
hedron Lett. 1999, 40, 6523–6526.
25. Molecular modeling was performed by MacroModel v8.1.
1. Dwek, R. A. Chem. Rev. 1996, 96, 683–720.
2. Essentials in Glyocbiology; Varki, A., Cummings, R.,
Esko, J., Freeze, H., Hart, G., Marth, J., Eds.; Cold
Spring Harbor Laboratory Press: New York, 1999.
3. Benz, I.; Schmidt, M. A. Mol. Microbiol. 2002, 45, 267–
276.
4. Wacker, M.; Linton, D.; Hitchen, P. G.; Nita-Lazar, M.;
Haslam, S. M.; North, S. J.; Panico, M.; Morris, H. R.;