Synthesis of five nona-β-(1→6)-d-glucosamines with various patterns of N-acetylation corresponding to the fragments of exopolysaccharide of Staphylococcus aureus

Article abstract of DOI:10.1016/j.carres.2011.02.018

A series of five 3-acetamidopropyl β-glycosides of nona-β-(1→6)-glucosamines containing two N-acetylglucosamine residues separated by a different number of glucosamine units with free amino groups have been synthesized using a convergent blockwise approac

Full text of DOI:10.1016/j.carres.2011.02.018

Carbohydrate Research 346 (2011) 905–913
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Carbohydrate Research
journal homepage: www.elsevier.com/locate/carres
Synthesis of five nona-b-(1?6)-D-glucosamines with various patterns
of N-acetylation corresponding to the fragments of exopolysaccharide
of Staphylococcus aureus
Olga N. Yudina a, Marina L. Gening a, Yury E. Tsvetkov a, Alexey A. Grachev a, Gerald B. Pier b,
Nikolay E. Nifantiev a,
⇑
a Laboratory of Glycoconjugate Chemistry, N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prosp. 47, 119991 Moscow, Russia
b Channing Laboratory, Brigham and Women’s Hospital, Harvard Medical School, 181 Longwood Avenue, Boston, MA 02115, USA
a r t i c l e i n f o
a b s t r a c t
Article history:
A series of five 3-acetamidopropyl b-glycosides of nona-b-(1?6)-glucosamines containing two N-acetyl-
glucosamine residues separated by a different number of glucosamine units with free amino groups have
been synthesized using a convergent blockwise approach. Oxazoline glycosylation was used to introduce
N-acetylglucosamine residues. These nonasaccharides are structurally related to the poly-N-acetylgluco-
samine (PNAG) extracellular polysaccharide of Staphylococcus aureus and can be used as models for bio-
chemical and immunological studies.
Received 18 October 2010
Received in revised form 7 February 2011
Accepted 16 February 2011
Available online 23 February 2011
Keywords:
Ó 2011 Elsevier Ltd. All rights reserved.
Staphylococcus aureus
Poly-b-(1?6)-N-acetylglucosamine
PNAG
Oligoglucosamines
Convergent synthesis
Oxazoline
1. Introduction
Previously we have described the synthesis of spacer-armed oli-
go-b-(1?6)-glucosamines consisting of 5, 7, 9, and 11 glucosamine
Poly-b-(1?6)-N-acetylglucosamine (PNAG) is a surface capsular
polysaccharide that also mediates intercellular adherence of cells of
Staphylococcus aureus.1 PNAG is also produced byStaphylococcus epi-
dermidis,2 Escherichia coli,3 Yersinia pestis,4 Bordetella pertussis,5
Acinetobacter baumannii6, and others.7 This antigen has good poten-
tial for use as an effective immunotherapeutic agent, but elicitation
of protective antibodies depends on the degree of N-acetylation of
the immunogens used.8 However, finding the optimal glycoform
needed for eliciting high titers of protective antibody is a difficult
and empiric task. When PNAG is isolated from bacterial sources, a
heterogeneousmixture of poly- and oligo-saccharides with different
immunological activities is obtained. Protective antibodies are elic-
ited when a de-N-acetylated form of PNAG (dPNAG, <30% of acety-
lated amino groups) is used in conjugate vaccines.7 Preparation of
dPNAG from native PNAG is imprecise and, therefore, synthetic
oligoglucosamines with glucosamine units bearing acetylated and
free amino groups in defined positions are needed to determine
the structure of optimal epitopes needed to induce protective
antibodies.
residues and a series of corresponding per-N-acetylated deriva-
tives.9 Penta- and nonasaccharides were further conjugated to a
carrier protein that was used for animal immunizations.7 In con-
trast to the conjugates of the fully N-acetylated ligands, the oligo-
glucosamine conjugates elicited high titers of the antibody that
bound both native, highly acetylated PNAG and poorly acetylated
dPNAG and were able to protect mice from skin abscesses caused
by S. aureus challenge.7
A series of oligo-b-(1?6)-N-acetylglucosamines containing 3–5
monosaccharide residues were synthesized by Nitz et al. using an
acid reversion reaction of N-acetylglucosamine in HFÁpyridine.10
These oligosaccharides were further conjugated to bovine serum
albumin and resultant glycoconjugates were proposed as potential
vaccines against PNAG producing bacterial strains but no results of
biological experiments have been reported so far.
In order to ascertain, if a combination of glucosamine and
N-acetylglucosamine residues may form a protective epitope, a
series of five nonasaccharides 1–5 (Fig. 1) containing two N-acety-
lated units separated by 1–5 glucosamine residues have been
prepared. The degree of N-acetylation in this case is about 20%
and theoretically these synthetic nonasaccharides may represent
specific fragments of dPNAG.
⇑
Corresponding author. Tel./fax: +7 499 135 8784.
E-mail address: nen@ioc.ac.ru (N.E. Nifantiev).
0008-6215/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.carres.2011.02.018

906
O. N. Yudina et al. / Carbohydrate Research 346 (2011) 905–913
HO
1
2
3
4
5
O
HO
HO
O
O
H2N
HO
O
HO
O
AcNH
HO
O
HO
O
HO
H2N
HO
O
O
HO
HO
HO
O
O
AcNH
HO
HO
O
O
H2N
HO
HO
O
O
H2N
HO
O
HO
O
AcNH
HO
HO
O
O
H2N
HO
O
HO
HO
O
H2N
HO
O
O
H2N
HO
O
HO
O
HO
HO
HO
O
O
H2N
HO
HO
O
O
H2N
HO
O
O
O
O
O
O
NHAc
NHAc
NHAc
NHAc
NHAc
H2N
HO
HO
HO
O
O
AcNH
HO
HO
O
H2N
O
AcNH
HO
HO
O
O
H2N
HO
HO
O
HO
O
H2N
HO
HO
O
O
H2N
HO
HO
O
O
HO
HO
O
O
H2N
HO
HO
O
O
H2N
HO
HO
O
H2N
HO
HO
O
O
H2N
HO
HO
O
H2N
O
AcNH
HO
HO
O
O
AcNH
HO
HO
O
HO
O
H2N
HO
HO
O
O
H2N
HO
HO
O
O
HO
HO
O
O
H2N
HO
HO
O
O
H2N
HO
HO
O
H2N
HO
HO
O
O
H2N
HO
HO
O
H2N
O
AcNH
HO
HO
O
O
H2N
HO
HO
O
O
H2N
HO
HO
O
O
AcNH
HO
HO
O
O
H2N
HO
HO
O
H2N
O
HO
HO
O
H2N
HO
HO
H2N
O
O
H2N
HO
HO
O
O
HO
HO
H2N
O
O
AcNH
HO
HO
H2N
Figure 1. Target selectively N-acetylated nonasaccharides. Dashed lines show the retrosynthetic disconnections of the nonasaccharide structures.
benzoylation reaction, viz. first with benzoic anhydride and then
2. Results and discussion
with benzoyl chloride, was more effective in forming b-benzoate
(a:b—1:3.5) and also avoided production of the undesirable N-ben-
The key step in the synthesis of nonasaccharides 1–5 was the
choice of a precursor for N-acetylglucosamine units (‘pre-NAc-
block’). One of the possible solutions was the use of a synthetic
block with N-protecting groups which could be selectively
removed in the presence of two other N-protections: one in the
monosaccharide unit which is a precursor of the glucosamine unit
(‘pre-NH2-block’) and another N-protecting group in the spacer
arm for possible conjugation to different carriers. Based on the suc-
cessful synthesis of the homo-oligosaccharide ligands,7,9 we
planned to use N-phthaloyl groups for pre-NH2-blocks and N-ben-
zyloxycarbonyl group for the spacer derived from 3-aminopropa-
nol. Therefore, the pre-NAc-block had to be readily available,
effective as a b-stereoselective glycosyl donor, and easily convert-
ible to the corresponding N-acetyl derivative. To meet these
requirements, the derivative of N-acetylglucosamine itself was
chosen as the pre-NAc-block. The main advantage of this approach
was the possibility of avoiding the steps of selective deprotection
and further N-acetylation.
zoylation product. Compound 8 was isolated from the anomeric
mixture and subjected to detritylation–acetylation by acetolysis
in the presence of BF3ÁEt2O to form compound 9. Reaction of 9 with
FeCl3 resulted in the formation of oxazoline 10 in a yield of 75%
(30% overall from 6).
It is known that glycosylation with oxazolines usually proceeds
with moderate yields but is relatively more efficient in the case of
primary hydroxyl groups including 6-OH groups of hexopyra-
noses.11 Nevertheless, we planned the synthetic schemes in such
a way as to avoid glycosylations with oxazolines for the assembly
of large oligosaccharide blocks. Thus, oxazoline 10 was used as the
glycosyl donor only in the reaction with monosaccharide acceptor
11.9,12 This reaction proceeded in the presence of TfOH in dichloro-
ethane at 50 °C and furnished disaccharide 12 with two different
N-substituents (‘mixed’ disaccharide) in 79% yield. Disaccharide
acceptor 13 obtained after selective deacetylation of 12 was gly-
cosylated with bromide 15 prepared from thioglycoside 149 to
form the mixed trisaccharide 16 (91%). In our synthetic scheme
mixed disaccharide 12 and trisaccharide 16 were used to introduce
N-acetylglucosamine fragments onto the growing oligosaccharide
chain. Previously a combination of glycosyl bromides and thiogly-
cosides proved to be effective for the synthesis of homo-oligosac-
charides.9 Bromide 159 also reacted with glycosyl acceptor 11 to
The pre-NAc-block was prepared as follows. N-Acetylglucosa-
mine 6 was successively tritylated and benzoylated with benzoyl
chloride to give a mixture of a- and b-benozoates 7 and 8 in a ratio
of ꢀ2:1 (Scheme 1). Since only b-isomer is suitable for further con-
version to oxazoline, we tried to improve the conditions of the ben-
zoylation reaction to maximize the formation of 8. A two-step

O. N. Yudina et al. / Carbohydrate Research 346 (2011) 905–913
907
HO
TrO
a
O
HO
HO
O
BzO
BzO
OH
R
AcNH
AcNH
AcO
6
7
α
R = OBz
8 R = βOBz
O
b
BzO
BzO
OBz
AcNH
9
c
AcO
HO
AcO
O
R
PhthN
O
O
BzO
BzO
BzO
BzO
BzO
BzO
SEt
PhthN
N
O
10
11
14
15
R = SEt
R = Br
f
g, 11
d
RO
RO
O
BzO
BzO
O
O
BzO
BzO
O
O
PhthN
BzO
BzO
O
SEt
AcNH BzO
BzO
SEt
PhthN
17
R = Ac
18 R = Η
PhthN
15
e
12
R = Ac
13 R = Η
e
g, 15
g,
AcO
AcO
O
BzO
BzO
O
O
BzO
BzO
O
O
PhthN
BzO
BzO
O
PhthN
O
BzO
BzO
O
O
PhthN
BzO
BzO
O
AcNH BzO
BzO
SEt
SEt
PhthN
PhthN
19
16
Scheme 1. Synthesis of oxazoline block 10 and key trisaccharides 16 and 19. Reagents: (a) (1) TrCl, Py, rt; (2) Bz2O, Py, 60 °C; (3) BzCl, Py; (b) BF3ÁEt2O, Ac2O; (c) FeCl3, CH2Cl2;
(d) TfOH, Cl2CH2CH2Cl2, MS AW300, 50 °C; (e) AcCl, MeOH, CH2Cl2; (f) Br2, CH2Cl2; (g) HgBr2, Hg(CN)2, CH3CN.
furnish disaccharide 17. Deacetylation of 17 resulted in the forma-
tion of the 6-hydroxy derivative 18 and its further glycosylation
afforded the trisaccharide block 19 in 66% yield.
The convergent schemes using the minimal number of synthetic
blocks were developed for the assembly of the target nonasaccha-
rides (Scheme 2). The size of blocks in each case was chosen in such
a way as to provide an opportunity for isolation of the products by
gel-permeation chromatography after each glycosylation step.
Gel-permeation chromatography on the hydrophobic BioBeads
gel is a useful alternative for isolation and purification of glycosyl-
ation products when the product and the starting compounds are
hardly separable by conventional silica gel column chromatogra-
phy. There are two prerequisites for the successful use of this
method: the product and the starting compounds must differ
strong enough in their molecular masses (hence the choice of the
synthetic blocks for the assembly of oligosaccharides) and must
H
O
H
O
17
a +
; b
17
a +
; b
O
O
BzO
O
NHZ
BzO
HO
NHZ
O
NHZ
BzO
BzO
PhthN
PhthN
4
2
20
22
(63%)
21
a + 12 ; b
HO
O
O
BzO
BzO
BzO
O
O
NHZ
AcO
AcNH
BzO
O
PhthN
BzO
O
5
BzO
a + 16 ; b
23
O
(36%)
PhthN
BzO
BzO
O
O
AcNH BzO
O
BzO
O
O
PhthN BzO
c
BzO
O
BzO
O
5
NHZ
1
AcNH
BzO
PhthN
24 (44%)
Scheme 2. Synthesis of nonasaccharide 24. Reagents: (a) NIS, TfOH, MS 4 Å, CH2Cl2; (b) AcCl, MeOH, CH2Cl2; (c) (1) H2 Pd(OH)2/C, MeOH–THF–H2O; (2) Ac2O, Py; (3)
N2H4ÁH2O, EtOH.

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O. N. Yudina et al. / Carbohydrate Research 346 (2011) 905–913
be soluble in toluene, the solvent of choice for this type of chroma-
tography. Thus, the final step involved a glycosylation ‘3+6’ using
mixed trisaccharide block 16. This block was also used in earlier
stages for the assembly of some of the nonasaccharides. The syn-
thesis of nonasaccharide 1 is described here in detail as an exam-
ple, the other four nonasaccharides were synthesized analogously
using respective building blocks depicted in Scheme 3. Glycosyla-
tion of 3-(benzyloxycarbonylamino)propanol 20 with disaccharide
thioglycoside 179 and subsequent removal of the O-acetyl group
from the non-reducing glucosamine furnished the known spacer-
armed disaccharide 21. The same reaction sequence was used to
obtain tetrasaccharide 22 in 63% yield. Further glycosylation with
mixed disaccharide 12 and deacetylation afforded hexasaccharide
23 (36%). The final reaction of 23 with mixed trisaccharide 16
resulted in the formation of nonasaccharide 24 in only 40% yield.
Unfortunately, all the reactions involving mixed blocks bearing
N-acetylglucosamine residues were less effective (yields 20–50%)
than corresponding glycosylations with homo-oligosaccharide
blocks containing only N-phthaloyl protecting groups (60–90%).9
All low-yield glycosylation reactions were accompanied by exten-
sive decomposition of a glycosyl donor with the formation of a
range of unidentified products, whereas an unreacted glycosyl
acceptor could be recovered from the reaction mixture. This is in
accordance with general observations of other examples of glyco-
sylation involving N-acetylglucosamine blocks.13–15 Lower yields
in the case of N-acetylated oligosaccharide blocks are attributed
to some specific intermolecular interactions of an unidentified
nature.
We also tried to vary the conditions such as dilution of the reac-
tion mixtures and the use of acetonitrile as a solvent for NIS/TfOH-
promoted glycosylation, but in all cases we failed to improve the
yields of the reactions with N-acetylglucosamine oligosaccharides.
Total deprotection of 24 with the formation of 1 was achieved as
described before for homo-oligosaccharides.9 Benzyloxycarbonyl
group in the spacer-arm was selectively removed to liberate an
amino group which may be used at this step for the introduction
of an appropriate linker for the conjugation.7 But currently, these
molecules were needed in a non-conjugated form, and, therefore,
the amino group in the aminopropyl moiety was acetylated. Fur-
ther one-step removal of all O-acyl and N-phthaloyl groups by
hydrazinolysis in boiling ethanol afforded nonasaccharide 1. The
synthesis of nonasaccharides 2–5 was accomplished similarly by
combining mono- and oligosaccharide blocks 12, 16, 17, 19, and
25 in the proper order according to the reaction sequences shown
in Scheme 3.
The NMR characterization of all final and intermediate products
was complicated due to close chemical nature of these compounds.
The presence of a large number of uniform monosaccharide units
made it difficult to attribute signals in NMR spectra to a certain
residue for oligomers longer than a trisaccharide. Therefore, NMR
AcO
AcO
O
O
4
2
BzO
BzO
O
O
BzO
c
BzO
c
O
O
PhthN
PhthN
BzO
BzO
BzO
O
O
BzO
O
O
AcNH BzO
BzO
AcNH BzO
O
O
BzO
O
O
O
O
PhthN
BzO
BzO
PhthN
BzO
O
BzO
O
2
BzO
4
BzO
a + 16 ; b
O
NHZ
O
NHZ
16
a +
; b
AcNH
AcNH
BzO
BzO
28
(28%)
PhthN
PhthN
4
34 (19%)
2
HO
H
O
O
BzO
BzO
O
O
BzO
O
O
O
O
PhthN BzO
BzO
BzO
O
O
BzO
PhthN
BzO
O
NHZ
AcNH
BzO
O
BzO
3
17
BzO
BzO
a +
; b
O
NHZ
AcNH
PhthN
16
27 (60%)
a +
; b
4
PhthN
33
(55%)
2
HO
H
O
HO
17
O
PhthN
a +
; b
16
16
O
O
a +
; b
BzO
BzO
O
NHZ
O
NHZ
BzO
BzO
O
BzO
BzO
O
PhthN
O
PhthN BzO
3
BzO
O
25
BzO
O
NHZ
AcNH
26
BzO
(85%)
PhthN
32 (67%)
2
20
21
a +
; b
a + 12 ; b
HO
O
O
BzO
HO
BzO
O
BzO
BzO
O
3
NHZ
O
AcNH
BzO
O
a + 17 ; b
BzO
PhthN
O
PhthN BzO
BzO
O
a + 19 ; b
O
BzO
29
(68%)
AcNH
O
NHZ
NHZ
NHZ
BzO
PhthN
O
H
35
(64%)
O
BzO
BzO
O
H
O
O
AcNH
O
BzO
O
O
PhthN
BzO
BzO
O
O
a + 16 ; b
2
BzO
BzO
NHZ
O
BzO
16
BzO
a +
; b
PhthN
O
BzO
PhthN
4
O
BzO
30
AcNH
(71%)
3
O
AcO
AcO
BzO
O
PhthN
O
BzO
BzO
36 (45%)
O
O
BzO
BzO
O
O
PhthN
BzO
PhthN
BzO
O
O
BzO
BzO
O
O
AcNH BzO
BzO
AcNH BzO
O
O
BzO
O
O
O
BzO
PhthN
BzO
PhthN
O
BzO
c
BzO
3
O
5
c
BzO
BzO
O
O
NHZ
AcNH
BzO
BzO
O
AcNH
PhthN
31
(33%)
PhthN
3
5
3
37
(35%)
Scheme 3. Synthesis of nonasaccharides 2–5. Reagents: (a) NIS, TfOH, MS 4 Å, CH2Cl2; (b) AcCl, MeOH, CH2Cl2; (c) (1) H2, Pd(OH)2/C, MeOH–THF–H2O; (2) Ac2O, Py; (3)
N2H4ÁH2O, EtOH.

O. N. Yudina et al. / Carbohydrate Research 346 (2011) 905–913
909
data of the higher oligosaccharides were only used to establish the
length of the oligosaccharide (by comparison of integral intensities
of relevant groups of signals) and the number of GlcNAc units.
Deprotected oligosaccharides 1–5 were also characterized by high
resolution mass-spectrometry.
mixture was heated under reflux for 3 h, then concentrated and
co-concentrated several times with toluene under diminished
pressure. The residue was purified on the TSK HW-40S column in
0.1 M AcOH to give a pure oligo-b-(1?6)-glucosamine.
3.5. 2-Methyl-(6-O-acetyl-3,4-di-O-benzoyl-1,2-dideoxy-
a-D-
glucopyrano)-[2,1-d]-2-oxazoline (10)
3. Experimental
Trityl chloride (16.4 g, 58.7 mmol) was added to a suspension of
N-acetylglucosamine 6 (10 g, 45.2 mmol) in pyridine (200 mL) and
the mixture was stirred for 7 h at ꢀ60 °C. Then benzoic anhydride
(24.5 g, 108 mmol) was added and the resulting mixture was stir-
red for 3 days at ꢀ60 °C. Then the reaction mixture was cooled to
0 °C and benzoyl chloride (23.7 mL, 203.4 mmol) was added drop-
wise. After being kept at rt for 48 h, the mixture was cooled to 0 °C
and MeOH (100 mL) was added. The resulting solution was con-
centrated, co-evaporated with toluene, dissolved in CHCl3, and
washed successively with 5% H2SO4, water, and saturated NaHCO3.
The organic layer was concentrated and the residue purified by sil-
ica gel column chromatography (toluene–acetone, 9:1) to give b-
3.1. General methods
NMR spectra were recorded on Bruker DRX-500 and Bruker
AM-300 instruments. Spectra of protected oligosaccharides were
measured for solutions in CDCl3, and 1H NMR chemical shifts were
referenced to a residual solvent signal. NMR spectra of free oligosac-
charides were measured for solutions in D2O. Optical rotation values
were measured on a JASCO DIP-360 polarimeter at 22 2 °C. TLC
was performed on Silica Gel 60 F254 plates (E. Merck), and visualiza-
tion was accomplished using UV light or by charring with 10% H3PO4
in ethanol. Column chromatography was carried out on Silica Gel 60
(40–63 lm, E. Merck). Gel-permeation chromatography of pro-
isomer 8 (15 g, 43%),
a-isomer 7 (2.4 g, 6%), and a mixture 7+8
tected oligosaccharides was performed on columns with Bio-Beads
SX-3 (15 Â 500 mm) or Bio-Beads SX-1 (20 Â 600 mm) (Bio-Rad
Laboratories) in toluene. Gel-permeation chromatography of free
oligosaccharides was performed on a column with TSK HW-40 (S)
(25 Â 400 mm) in 0.1 M AcOH. HRESIMS spectra were obtained on
Finnigan LTQ FT (Thermo Scientific)and MicrOTOFII (Bruker Dalton-
ics) instruments. All reactions involving air- or moisture-sensitive
reagents were carried out using dry solvents under dry argon.
(7.4 g, 21%).
Compound 7. 1H NMR (CDCl3): d 8.25–7.00 (m, 30H, Ar), 6.70 (d,
1H, J1,2 3.5 Hz, H-1), 6.05 (m, 1H, NH), 5.91 (t, 1H, J3,4 9.6 Hz, H-4),
5.51 (t, 1H, J3,2 10.3 Hz, H-3), 4.80 (dd, 1H, H-2), 4.22 (m, 1H, H-5),
3.39 (dd, 1H, J5,6a 4.2 Hz, J6a,6b 10.7 Hz, H-6a), 3.13 (dd, 1H, J6b,5
4.0 Hz, H-6b), 1.85 (s, 3H, CH3CON); 13C NMR (CDCl3): d 170.27,
167.16 (C@O), 144.09–127.05 (Ar), 91.70 (C-1), 74.90 (C-5), 73.50
(C-3), 70.59 (C-4), 62.13 (C-6), 53.43 (C-2), 23.10 (CH3CON).
Compound 8. 1H NMR (CDCl3): d 6.05 (d, 1H, J1,2 8.7 Hz, H-1),
5.94 (d, 1H, JNH,2 7.4 Hz, NH), 5.80 (t, 1H, J3,4 9.6 Hz, H-4), 5.52 (t,
1H, J3,2 10.1 Hz, H-3), 4.83 (dd, 1H, H-2), 3.90 (m, 1H, H-5), 3.43
(dd, 1H, J6a,5 2.5 Hz, J6a,6b 8.3 Hz, H-6a), 3.20 (dd, 1H, J6b,5 4.2 Hz,
H-6b), 1.79 (s, 3H, CH3CO); 13C NMR (CDCl3): d 170.21, 164.55
(C@O), 143.33–125.14 (Ar), 93.70 (C-1), 74.90 (C-5), 73.42 (C-3),
68.52 (C-4), 61.93 (C-6), 53.32 (C-2), 23.03 (CH3CON).
3.2. General procedure for selective deacetylation in the
presence of benzoyl groups
A solution of a 6-O-acetyl derivative (1 mmol) in CH2Cl2 (6 mL)
was diluted with absolute MeOH (20 mL) and then AcCl (0.2 mL)
was added under cooling in an ice-bath. The mixture was kept
for 16 h at rt and then concentrated. The residue was purified by
flash chromatography on silica gel (EtOAc–toluene) to give the
product with a free terminal 6-OH group.
Compound 8 (5 g, 6.4 mmol) was dissolved in Ac2O (20 mL) and
BF3ÁEt2O (2 mL, 15.6 mmol) was added at 0 °C, and the resultant
mixture was kept at rt for 30 min. Then the reaction mixture was
poured into ice-cold water and extracted with CHCl3. The organic
layer was washed with saturated NaHCO3, concentrated, and co-
evaporated with toluene. The residue was subjected to silica gel
column chromatography (toluene–acetone 50:1?4:1) to give 9
3.3. General procedure for NIS-TfOH-catalyzed glycosylation
A solution of an ethyl thioglycoside (0.1 mmol) and a glycosyl
acceptor (0.09 mmol) in freshly distilled anhydrous CH2Cl2 (1 mL)
containing 4 Å MS (130 mg) was stirred at rt under argon for 1 h
and then cooled to À20 °C. NIS (0.2 mmol) and TfOH (0.04 mmol)
were successively added and the resulting mixture was stirred
for an additional 30 min at À20 °C. The reaction was quenched
with a drop of pyridine, allowed to attain rt, diluted with CH2Cl2,
and filtered through Celite. The filtrate was washed with 1 M
Na2S2O3, then with water, dried with Na2SO4, and concentrated.
The residue was purified by gel chromatography either on the
Bio-Beads SX-1 (hexa- and nonasaccharides) or on the Bio-Beads
SX-3 (lower oligosaccharides) column in toluene.
(2.63 g, 71%). [
a
]
D
À59 (c 1, CHCl3). 1H NMR (CDCl3): d 8.24–7.10
(m, 15H, Ar), 6.03 (d, 1H, J1,2 8.7 Hz, H-1), 5.86 (d, 1H, JNH,2
9.3 Hz, NH), 5.65 (m, 2H, H-3, H-4), 4.76 (m, 1H, H-2), 4.40–4.20
(m, 2H, H-6a, H-6b), 4.18 (m, 1H, H-5), 2.10 (s, 3H, CH3COO),
1.76 (s, 3H, CH3CON); 13C NMR (CDCl3): d 170.61, 170.17, 167.02,
165.22, 162.87, 162.22 (C@O), 133.91–128.26 (Ar), 93.58 (C-1),
73.12 (C-3, C-5), 68.64 (C-4), 62.19 (C-6), 53.33 (C-2), 23.20
(CH3CON), 20.70 (CH3COO).
To a solution of 9 (2.5 g, 4.3 mmol) in anhydrous CH2Cl2
(190 mL) was added FeCl3 (2.5 g, 15.4 mmol), and the reaction mix-
ture was stirred for 2 h at rt under argon, then washed with H2O,
and concentrated. The residue was purified by silica gel column
chromatography (petroleum ether–acetone, gradient of acetone
3.4. General procedure for total deprotection of
oligoglucosamines
0?30%) to provide compound 10 (1.48 g, 75%). [
a]
À49 (c 1,
D
CHCl3). 1H NMR (CDCl3): d 8.10–7.10 (m, 10H, Ar), 6.11 (d, 1H,
J1,2 7.5 Hz, H-1), 5.67 (m, 1H, H-3), 5.35 (d, 1H, J4,5 8.1 Hz, H-4),
4.38–4.31 (m, 2H, H-2, H-6a), 4.28 (dd, 1H, J6b,5 5.6 Hz, J6b,6a
12.1 Hz, H-6b), 3.84 (m, 1H, H-5) 2.12 (CH3), 1.98 (CH3COO); 13C
NMR (CDCl3): d 170.50 (C@O), 166.39 (C@N), 164.67 (C@O),
133.50, 130.27–126.97 (Ar), 99.55 (C-1), 69.92 (C-3), 68.38 (C-4),
68.16 (C-5), 64.57(C-2), 62.05 (C-6), 20.56 (CH3COO). 13.89 (CH3).
Anal. Calcd for C24H23NO8: C, 63.57; H, 5.11; N, 3.09. Found: C,
62.73; H, 5.11; N, 2.92.
A protected oligosaccharide (0.01 mmol) was dissolved in a
mixture of MeOH–THF (1:1.5 mL) and Pd(OH)2/C (50 mg) was
added. The resulting mixture was stirred under an H2 atmosphere
(1 atm) overnight, then filtered through Celite and the filtrate was
concentrated. The product of hydrogenolysis was dissolved in pyr-
idine (0.5 mL) and treated with Ac2O (0.2 mL) and the resulting
mixture was kept for 1 h at rt, and concentrated. The residue was
dissolved in EtOH (10 mL) and N2H4ÁH2O (1 mL) was added. The

910
O. N. Yudina et al. / Carbohydrate Research 346 (2011) 905–913
3.6. Ethyl 2-acetamido-6-O-acetyl-3,4-di-O-benzoyl-2-deoxy-b-
-glucopyranosyl-(1?6)-3,4-di-O-benzoyl-2-deoxy-2-
phthalimido-1-thio-b- -glucopyranoside (12)
CH3CH2S), 2.00 (s, 3H, CH3COO), 1.95 (s, 3H, CH3CON), 1.25 (t, 3H,
SCH2CH3); 13C NMR (CDCl3): d 167.05, 166.47, 165.85, 165.54,
165.49, 165.16 (C@O), 134.1–123.46 (Ar), 101.87 (C-1II), 97.91 (C-
1III), 80.40 (C-1I), 77.14 (C-5I), 74.01 (C-5II), 73.43 (C-3II), 72.22
(C-3I), 71.93 (C-5III), 71.00 (C-3III), 69.85 (C-4II), 69.68 (C-4I, C-
4III), 68.02 (C-6II, C-6I), 62.38 (C-6III), 54.75 (C-2I), 54.12 (C-2II),
53.49 (C-2III), 23.10 (CH3CON), 20.56 (CH3COO), 14.83 (SCH2CH3).
D
D
A solution of oxazoline 10 (0.43 g, 0.64 mmol) and acceptor 6
(0.36 g, 0.64 mmol) in anhydrous dichloroethane (10 mL) contain-
ing MS AW 300 (1 g) was stirred for 30 min at rt under argon, then
TfOH (0.03 mL, 0.32 mmol) was added and the mixture was stirred
and heated under reflux for 40 h. After cooling to rt, the reaction
was quenched with pyridine (0.05 mL), diluted with CHCl3, and fil-
tered through Celite. The filtrate was washed with water and con-
centrated. The residue was purified by silica gel chromatography
(gradient 0?40% of acetone in petroleum ether) to give disaccha-
HRESIMS: found m/z 1514.4237 [M+H]+; calcd for C82H72N3O24
S
1514.4221.
3.8. 3-(Benzyloxycarbonylamino)propyl 3,4-di-O-benzoyl-2-
deoxy-2-phthalimido-b-
benzoyl-2-deoxy-2-phthalimido-b-
di-O-benzoyl-2-deoxy-2-phthalimido-b-
D
-glucopyranosyl-(1?6)-3,4-di-O-
-glucopyranosyl-(1?6)-3,4-
-glucopyranosyl-
À4 (c 1, CHC13). 1H NMR (CDCl3): d
D
ride 12 (0.514 g, 79%). [a]
D
7.95–7.20 (m, 24H, Ar), 6.28 (t, 1H, J3,2 9.7 Hz, H-3I), 6.10 (d, 1H,
JNH,2 8.9 Hz, NH), 5.61–5.54 (m, 3H, H-1I, H-3II, H-4I), 5.48 (t, 1H,
J3,4 9.7 Hz, H-4II), 4.67 (d, 1H, J1,2 8.4 Hz, H-1II), 4.61 (t, 1H, J2,1
10.4 Hz, H-2I), 4.30 (dd, 1H, H-2II), 4.24–4.13 (m, 3H, H-6aI, H-
6aII, H-6bII), 4.10 (m, 1H, H-5I), 3.85 (m, 1H, H-5II), 3.65 (dd, 1H,
J6b,5 5.2 Hz, J6b,6a 11.63 Hz, H-6bI), 2.85–2.65 (m, 2H, CH3CH2S),
1.95 (s, 3H, H1, CH3COO), 1.97 (s, 3H, CH3CON), 1.28 (t, 3H,
CH3CH2S); 13C NMR (CDCl3): d 170.63, 170.31, 167.93, 167.07,
165.71, 165.49 (C@O), 134.13–123.65 (Ar), 101.87 (C-1II), 80.67
(C-1I), 77.38 (C-5I), 73.20 (C-3II), 72.00 (C-5II, C-3I), 69.83 (C-4I),
69.27(C-4II), 68.29 (C-6I), 62.42 (C-6II), 54.30 (C-2II), 53.59 (C-2I),
23.44 (SCH2CH3), 23.18 (CH3CON), 20.60 (CH3COO), 14.94
(SCH2CH3). Anal. Calcd for C54H50N2O16S: C, 63.90; H, 4.96; N,
2.76. Found: C, 63.84; H, 5.03; N, 2.63.
D
(1?6)-3,4-di-O-benzoyl-2-deoxy-2-phthalimido-b-D-
glucopyranoside (22)
Glycosyl acceptor 21 (210 mg, 0.168 mmol), obtained in the
reaction of disaccharide 17 and compound 20 as described be-
fore,12 was glycosylated with donor 17 (204 mg, 0.185 mmol) fol-
lowed by O-deacetylation as described in Sections 3.3 and 3.2 to
give tetrasaccharide 22 (215 mg, 63% over two stages). Selected
1H NMR data (CDCl3): d 8.00–7.05 (m, 61H, Ar), 6.25 (t, 1H, J3,2
9.7 Hz, H-3IV), 6.20–6.05 (m, 3H, 3 H-3), 5.63 (d, 1H, J1,2 8.4 Hz,
H-1IV), 5.04 (s, 2H, CH2Ph), 3.08 (m, 2H, OCH2CH2CH2N), 1.80 (br
s, 1H, OH), 1.61 (m, 2H, OCH2CH2CH2N); Selected 13C NMR data
(CDCl3): d 97.99 (C-1), 97.74 (C-1), 97.44 (2 C-1), 61.26 (C-6IV),
54.75 (2C-2), 54.63 (2 C-2), 38.02 (CH2CH2CH2N), 29.45
(CH2CH2CH2N). HRESIMS: found m/z 1146.8011 [M+2Na]2+; calcd
for C125H101N5Na2O36 1146.8005.
3.7. Ethyl 6-O-acetyl-3,4-di-O-benzoyl-2-deoxy-2-phthalimido-
b-
2-deoxy-b-
1-thio-2-phthalimido-b-
D
-glucopyranosyl-(1?6)-2-acetamido-3,4-di-O-benzoyl-
-glucopyranosyl-(1?6)-3,4-di-O-benzoyl-2-deoxy-
-glucopyranoside (16)
D
3.9. 3-Acetamidopropyl 2-amino-2-deoxy-b-
(1?6)-2-acetamido-2-deoxy-b- -glucopyranosyl-(1?6)-2-
amino-2-deoxy-b- -glucopyranosyl-(1?6)-2-acetamido-2-
deoxy-b- -glucopyranosyl-(1?6)-2-amino-2-deoxy-b-
glucopyranosyl-(1?6)-2-amino-2-deoxy-b- -glucopyranosyl-
(1?6)-2-amino-2-deoxy-b- -glucopyranosyl-(1?6)-2-amino-2-
deoxy-b- -glucopyranosyl-(1?6)-2-amino-2-deoxy-b-
glucopyranoside (1)
D-glucopyranosyl-
D
D
D
Disaccharide 12 (2.04 g, 2.01 mmol) was deacetylated as de-
scribed in Section 3.2. The product was purified by flash-chroma-
tography on silica gel (toluene–ethyl acetate, 2:1) to give
D
D-
D
D
disaccharide 13 (1.86 g, 95%). [
a
]
D
À12 (c 1, CHCl3). 1H NMR
D
D-
(CDCl3): d 8.00–7.05 (m, 24H, Ar), 6.27 (t, 1H, J3,2 9.7 Hz, H-3I),
5.99 (d, 1H, JNH,2 8.9 Hz, NH), 5.66–5.58 (m, 3H, H-3II, H-1I, H-4I),
5.31 (t, 1H, J4,3 9.6 Hz, H-4II), 4.71 (d, 1H, J1,2 8.4 Hz, H-1II), 4.61
(t, 1H, J2,1 10.4 Hz, H-2I), 4.26–4.18 (m, 2H, H-2II, H-6aI), 4.09 (m,
1H, H-5I), 3.73–3.55 (m, 4H, H-6bI, H-6aII, H-5II, H-6bII), 2.72–
2.61 (m, 2H, SCH2CH3), 1.92 (s, 3H, CH3CON), 1.55 (br. s, 1H, OH),
1.25 (t, 3H, SCH2CH3); 13C NMR (CDCl3): d 174.73, 170.23, 167.90,
166.51, 165.89, 165.51 (C@O), 134.22–123.61 (Ar), 101.39 (C-1II),
80.80 (C-1I), 76.70 (C-5I), 74.68 (C-3II), 73.15 (C-3I), 72.08 (C-5II),
70.02 (C-4I), 69.43 (C-4II), 67.63 (C-6II), 61.36 (C-6I), 54.20 (C-2I),
53.65 (C-2II), 23.45 (SCH2CH3), 23.14 (CH3CON), 14.94 (SCH2CH3).
A solution of bromide 158 (200 mg, 0.33 mmol) in anhydrous
CH3CN (2 mL) was added to a solution of glycosyl acceptor 13
(215 mg, 0.22 mmol), Hg(CN)2 (84 mg, 0.33 mmol), HgBr2 (32 mg,
0.4 mmol) in anhydrous CH3CN (5 mL) at rt under argon. The mix-
ture was stirred for 45 min, diluted with CHCl3, washed with a
mixture of saturated NaHCO3 and 1 M KBr, and the organic layer
was concentrated. Product 16 (305 mg, 91%) was isolated by gel
Hexasaccharide 23 was prepared by the reaction of glycosyl do-
nor 12 (66 mg, 0.065 mmol) with glycosyl acceptor 22 (130 mg,
0.06 mmol) as described in Section 3.3. The reaction was per-
formed twice, after the first run, unreacted acceptor 22 was recov-
ered and subjected to the same glycosylation. Deacetylation of the
product as described in Section 3.2 afforded hexasaccharide 23
(67 mg, total yield 36%). Selected 1H NMR data (CDCl3): d 6.72 (d,
1H, JNH,2 8.9 Hz, NH), 5.99 (t, 1H, J 9.9 Hz, H-3VI), 5.62 (d, 1H, J1,2
8.4 Hz, H-1I), 5.24 (t, 1H, J 8.4 Hz, H-4VI), 5.04 (s, 2H, CH2Ph), 3.03
(m, 2H, OCH2CH2CH2N), 1.75 (s, 3H, CH3CON). Selected 13C NMR
data (CDCl3): d 101.68 (C-1VI), 98.27 (C-1), 97.95 (C-1), 97.61 (C-
1), 97.53 (C-1), 97.03 (C-1), 62.7 (C-6 VI), 55.32 (5C-2), 54.67 (C-
2), 38.02 (CH2CH2CH2N), 29.45 (CH2CH2CH2N) 22.42 (CH3CON).
Glycosyl acceptor 23 (65 mg, 0.021 mmol) was glycosylated
with donor 16 (38 mg, 0.025 mmol) as described in Section 3.3 to
give nonasaccharide 24 (42 mg, 44%). [a] +19.5 (c 1, CHCl3). Se-
D
chromatography (BioBeads SX-3) in toluene. [
a
]
D +1.5 (c 1, CHCl3).
lected 1H NMR data (CDCl3): d 6.49 (d, 1H, JNH,2 8.9 Hz, NH), 6.39
(d, 1H, JNH,2 8.9 Hz, NH), 6.27 (t, 1H, J3,4 9.6 Hz, H-3), 6.21–6.05
(m, 8H), 5.68 (d, 1H, J1,2 8.4 Hz, H-1), 5.01 (s, 2H, CH2Ph), 3.01
(m, 2H, OCH2CH2CH2N), 1.92–1.89 (3s, 9H, CH3COO, 2CH3CON). Se-
lected 13C NMR data (CDCl3): d 101.90 (2C-1), 98.13 (C-1), 97.91
(3C-1), 97.73 (2C-1), 97.39 (C-1), 62.39 (C-6 IX), 54.64 (7C-2),
54.08 (2C-2), 38.02 (CH2CH2CH2N), 29.41 (CH2CH2CH2N) 23.04
(2CH3CON), 20.50 (CH3COO).
1H NMR (CDCl3): d 8.00–7.05 (m, 38H, Ar), 6.30–6.13 (m, 3H, H-3I,
NH, H-3III), 5.51–5.42 (m, 2H, H-4III, H-3II), 5.20 (t, 1H, J4,3 9.6 Hz, H-
4II), 5.15–5.07 (m, 3H, H-4I, H-1III, H-1I), 4.51 (t, 1H, J2,1 10.4 Hz, H-
2I), 4.49–4.42 (m, 2H, H-2III, H-1II), 4.29–4.22 (m, 2H, H-2II, H-6aIII),
4.17 (dd, 1H, J6b,5 2.6 Hz, J6b,6a 12.2 Hz, H-6bIII), 4.08–4.02 (m, 2H,
H-5III, H-6aI), 3.97–3.87 (m, 2H, H-5I, H-6aII), 3.38–3.20 (m, 2H,
H-5II, H-6bII), 3.50 (dd, 1H, J6b,5 3.4 Hz, H-6bI), 2.90–2.65 (m, 2H,

O. N. Yudina et al. / Carbohydrate Research 346 (2011) 905–913
911
Compound 24 (42 mg, 0.009 mmol) was deprotected as
described in Section 3.4 to give 1 (10 mg, 65%). 1H NMR (D2O):
d 4.70–4.83 (m, 7H, 7H-1), 4.57 (m, 2H, 2H-1), 4.31–4.18 (m, 8H),
3.98–3.85 (m, 9H), 3.85–3.60 (m, 24H), 3.60–3.49 (m, 10H),
3.49–3.40 (m, 3H), 3.35–3.29 (m, 1H), 3.27–3.19 (m, 1H), 3.10–
2.98 (m, 7H, 7H-2), 2.09 (s, 6H, 2CH3CON), 1.99 (s, 3H, CH3CON),
1.94 (s, 21H, CH3COOH), 1.87–1.81 (m, 2H, OCH2CH2CH2N). 13C
NMR (D2O): 103.02 (2C-1), 101.22 (2C-1), 101.01 (2C-1), 100.88
(C-1), 100.60 (C-1), 100.47 (C-1), 77.46, 77.06, 76.15, 75.98,
75.60, 74.77, 73.59, 73.50, 73.27, 70.93, 70.84, 69.62, 69.18, 61.62
(C-6IX), 56.93 (7C-2), 56.61 (2C-2), 37.35 (CH2CH2CH2N), 29.70
(CH2CH2CH2N), 24.19, 23.55, 23.19 (3CH3CON). HRESIMS: found
m/z 1650.721 [M+H]+; calcd for C63H115N10O40 1650.719.
62.43 (C-6IX), 54.89 (C-2), 54.75 (C-2), 54.65 (C-2), 54.43 (C-2),
54.03 (C-2), 53.85 (C-2), 53.38 (C-2), 53.15 (2C-2), 38.09
(CH2CH2CH2N), 29.45 (CH2CH2CH2N) 23.02 (2 CH3CON), 20.06
(CH3COO). HRESIMS: found m/z 2301.6700 [M+2NH4]2+; calcd for
C253H214N12O74 2301.6670.
3.12. 3-Acetamidopropyl 2-amino-2-deoxy-b-
(1?6)-2-acetamido-2-deoxy-b- -glucopyranosyl-(1?6)-2-
amino-2-deoxy-b- -glucopyranosyl-(1?6)-2-amino-2-deoxy-b-
-glucopyranosyl-(1?6)-2-acetamido-2-deoxy-b-
glucopyranosyl-(1?6)-2-amino-2-deoxy-b- -glucopyranosyl-
(1?6)-2-amino-2-deoxy-b- -glucopyranosyl-(1?6)-2-amino-2-
deoxy-b- -glucopyranosyl-(1?6)-2-amino-2-deoxy-b-
glucopyranoside (2)
D-glucopyranosyl-
D
D
D
D-
D
D
D
D-
3.10. 3-(Benzyloxycarbonylamino)propyl 3,4-di-O-benzoyl-2-
deoxy-2-phthalimido-b-
3,4-di-O-benzoyl-2-deoxy-b-
benzoyl-2-deoxy-2-phthalimido-b-
di-O-benzoyl-2-deoxy-2-phthalimido-b-
(1?6)-3,4-di-O-benzoyl-2-deoxy-2-phthalimido-b-
glucopyranosyl-(1?6)-3,4-di-O-benzoyl-2-deoxy-2-
phthalimido-b- -glucopyranoside (27)
D
-glucopyranosyl-(1?6)-2-acetamido-
-glucopyranosyl-(1?6)-3,4-di-O-
-glucopyranosyl-(1?6)-3,4-
-glucopyranosyl-
Compound 28 (60 mg, 0.013 mmol) was deprotected as de-
scribed in Section 3.4 to give 2 (12 mg, 57%). 1H NMR (D2O): d
4.80–4.68 (m, 7H, 7H-1), 4.59–4.51 (m, 2H, 2H-1), 4.28–4.16 (m,
7H), 3.98–3.81 (m, 8H), 3.80–3.57 (m, 18H), 3.56–3.42 (m, 9H),
3.42–3.37 (m, 2H), 3.33–3.25 (m, 1H), 3.16–3.25 (m, 1H), 2.93–
3.09 (m, 7H, 7H-2), 2.07 (s, 6H, 2CH3CON), 1.97 (s, 3H, CH3CON),
1.90 (s, 21H, CH3COOH), 1.77–1.84 (m, 2H, OCH2CH2CH2N); 13C
NMR (D2O): 102.95 (2C-1), 100.71 (4C-1), 100.40 (2C-1), 100.25
(C-1), 77.33, 76.05, 75.83, 75.46, 74.63, 73.24, 73.06, 70.72, 69.49,
69.04, 61.47 (C-6IX), 56.76 (7C-2), 56.49 (2C-2), 37.22
(CH2CH2CH2N), 29.56 (CH2CH2CH2N), 24.04, 23.43, 23.06
(3CH3CON). HRESIMS: found m/z 1650.720 [M+H]+; calcd for
D
D
D
D
-
D
Glycosyl donor 168 (90 mg, 0.066 mmol) was allowed to react
with acceptor 268 (74 mg, 0.045 mmol) as described in Section
3.3 with further deacetylation as described in Section 3.2 to give
hexasaccharide 27 (81 mg, 60%). [a] +10.5 (c 1, CHCl3). Selected
D
1H NMR data (CDCl3): d 6.42 (d, 1H JNH,2 8.7 Hz, NH), 6.27–6.05
(m, 5H, 5H-3), 5.63 (d, 1H, J1,2 8.2 Hz, H-1), 5.58 (t, 1H, J3,4
10.0 Hz, H-3V), 5.51–5.08 (m, 10H, 4H-1, 6H-4), 5.01 (s, 2H, CH2Ph),
4.53 (d, J1,2 8.3 Hz, H-1V), 4.50–4.39 (m, 3H, 3H-2), 4.34 (dd, 1H, J2,1
8.6 Hz, J2,3 10.5 Hz, H-2), 4.25 (dd, 1H, J2,1 8.5 Hz, J2,3 10.6 Hz, H-2),
4.16 (m, 1H, H-2V), 3.43 (m, 1H, OCH2CH2CH2N), 3.01 (m, 2H,
OCH2CH2CH2N), 1.91 (s, 3H, CH3CON), 1.55 (m, 2H, OCH2CH2CH2N).
Selected 13C NMR data (CDCl3): d 101.66 (C-1V), 98.20 (C-1), 98.04
(C-1), 97.89 (C-1), 97.42 (2 C-1), 61.14 (C-6VI), 54.79 (4C-2), 54.58
(2C-2), 38.09 (CH2CH2CH2N), 29.47 (CH2CH2CH2N) 23.72
(CH3CON). HRESIMS: found m/z 1575.9728 [M+2NH4]2+; calcd for
C63H115N10O40 1650.719.3
3.13. 3-(Benzyloxycarbonylamino)propyl 3,4-di-O-benzoyl-2-
deoxy-2-phthalimido-b- -glucopyranosyl-(1?6)-3,4-di-O-
benzoyl-2-deoxy-2-phthalimido-b- -glucopyranosyl-(1?6)-2-
acetamido-3,4-di-O-benzoyl-2-deoxy-2-b- -glucopyranosyl-
(1?6)-3,4-di-O-benzoyl-2-deoxy-2-phthalimido-b-
glucopyranosyl-(1?6)-3,4-di-O-benzoyl-2-deoxy-2-
phthalimido-b- -glucopyranosyl-(1?6)-3,4-di-O-benzoyl-2-
deoxy-2-phthalimido-b- -glucopyranoside (30)
D
D
D
D-
D
D
C
173H149N9O50 1575.9691.
Tetrasaccharide 29 was prepared by the reaction of glycosyl
acceptor 21 (90 mg, 0.02 mmol) with glycosyl donor 12 (120. mg,
0.118 mmol) as described in Section 3.3 and subsequent deacetyla-
tion as described in Section 3.2 (170 mg, 68% over two stages). Se-
lected 1H NMR data (CDCl3): d 6.51 (d, 1H, JNH,2 9.8 Hz, NH), 6.21–
6.08 (m, 3H, 3 H-3), 5.79 (t, 1H, J 10.0 Hz, H-3IV), 5.70–5.29 (m, 7H,
3H-1, 4H-4), 5.01 (s, 2H, CH2Ph), 4.91 (d, 1H, J1,2 8.3 Hz, H-1IV), 3.02
(m, 2H, OCH2CH2CH2N), 1.80 (s, 3H, CH3CON). Selected 13C NMR
data (CDCl3): d 100.87 (C-1IV), 98.53 (C-1), 98.13 (C-1), 97.72 (C-
1), 61.55 (C-6IV), 54.85 (2C-2), 54.75 (C-2), 54.23 (C-2), 38.00
(CH2CH2CH2N), 29.62 (CH2CH2CH2N), 23.21 (CH3CON).
Hexasaccharide 30 was prepared by the reaction of glycosyl
acceptor 29 (150 mg, 0.071 mmol) with donor 17 (86 mg,
0.078 mmol) as described in Section 3.3 with subsequent deacety-
lation as described in Section 3.2 (160 mg, 71% over two stages).
Selected 1H NMR data (CDCl3): d 6.51 (d, 1H, JNH,2 9.8 Hz, NH),
6.28–6.06 (m, 5H, 5H-3), 5.63–5.56 (m, 4H, 3H-1, H-3IV), 5.48 (d,
J1,2 8.34 Hz, H-1), 5.04 (s, 2H, CH2Ph), 4.56 (d, J1,2 8.3 Hz, H-1IV),
4.24 (m, 1H, H-2IV), 3.50 (m, 1H, OCH2CH2CH2N), 3.09 (m, 2H,
OCH2CH2CH2N), 1.98 (s, 3H, CH3CON), 1.52 (m, 2H, OCH2CH2CH2N);
Selected 13C NMR data (CDCl3): d 101.70 (C-1IV), 97.98 (C-1), 97.87
(2C-1), 97.65 (C-1), 97.61 (C-1), 61.35 (C-6VI), 54.78 (2C-2), 54.69
(2C-2), 54.64 (C-2), 54.28 (C-2), 38.08 (CH2CH2CH2N), 29.51
(CH2CH2CH2N) 23.17 (CH3CON). HRESIMS: found m/z 3138.8556
[M+Na]+; calcd for C173H141N7NaO50 3138.8598.
3.11. 3-(Benzyloxycarbonylamino)propyl-6-O-acetyl-3,4-di-O-
benzoyl-2-deoxy-2-phthalimido-b- -glucopyranosyl-(1?6)-2-
acetamido-3,4-di-O-benzoyl-2-deoxy-b- -glucopyranosyl-
(1?6)-3,4-di-O-benzoyl-2-deoxy-2-phthalimido-b-
glucopyranosyl-(1?6)-2-acetamido-3,4-di-O-benzoyl-2-deoxy-
b- -glucopyranosyl-(1?6)-3,4-di-O-benzoyl-2-deoxy-2-
phthalimido-b- -glucopyranosyl-(1?6)-3,4-di-O-benzoyl-2-
deoxy-2-phthalimido-b- -glucopyranosyl-(1?6)-3,4-di-O-
benzoyl-2-deoxy-2-phthalimido-b- -glucopyranosyl-(1?6)-3,4-
di-O-benzoyl-2-deoxy-2-phthalimido-b- -glucopyranosyl-
D
D
D
-
D
D
D
D
D
(1?6)-3,4-di-O-benzoyl-2-deoxy-2-phthalimido-b-D-
glucopyranoside (28)
Glycosyl acceptor 27 (90 mg, 0.029 mmol) was allowed to react
with donor 16 (52.5 mg, 0.035 mmol) as described in Section 3.3 to
give nonasaccharide 28 (36.5 mg, 28%). [a] +17 (c 1, CHCl3). Se-
D
lected 1H NMR data (CDCl3): d 6.41 (d, 1H, JNH,2 8.9 Hz, NH), 6.38
(d, 1H, JNH,2 8.7 Hz, NH), 6.26 (m, 1H, H-3), 6.20–6.02 (m, 6H, 6H-
3), 5.65 (d, 1H, J1,2 8.2 Hz, H-1), 5.57–5.48 (m, 2H, 2H-3), 4.98 (s,
2H, CH2Ph), 3.00 (m, 2H, OCH2CH2CH2N), 1.95 (s, 3H, CH3CON),
1.90 (s, 3H, CH3COO), 1.88 (s, 3H, CH3CON), 1.52 (m, 2H,
OCH2CH2CH2N); Selected 13C NMR data (CDCl3): d 102.09 (C-1),
101.79 (C-1), 98.19 (C-1), 97.98 (3C-1), 97.95 (2C-1), 97.48 (C-1),

912
O. N. Yudina et al. / Carbohydrate Research 346 (2011) 905–913
3.14. 3-(Benzyloxycarbonylamino)propyl 6-O-acetyl-3,4-di-O-
benzoyl-2-deoxy-2-phthalimido-b- -glucopyranosyl-(1?6)-2-
acetamido-3,4-di-O-benzoyl-2-deoxy-b- -glucopyranosyl-
(1?6)-3,4-di-O-benzoyl-2-deoxy-2-phthalimido-b-
glucopyranosyl-(1?6)-3,4-di-O-benzoyl-2-deoxy-2-
phthalimido-b- -glucopyranosyl-(1?6)-3,4-di-O-benzoyl-2-
deoxy-2-phthalimido-b- -glucopyranosyl-(1?6)-2-acetamido-
3,4-di-O-benzoyl-2-deoxy-b- -glucopyranosyl-(1?6)-3,4-di-O-
benzoyl-2-deoxy-2-phthalimido-b- -glucopyranosyl-(1?6)-3,4-
di-O-benzoyl-2-deoxy-2-phthalimido-b- -glucopyranosyl-
6.23–6.15 (m, 3H, 3 H-3), 5.63–5.22 (m, 8H, 3H-1, 4 H-4, H-3III),
5.16 (m, 1H, OCH2CH2CH2NH), 5.02 (s, 2H, CH2Ph), 4.53–4.41 (m,
3H, 2 H-2, H-1III), 3.02 (m, 2H, OCH2CH2CH2N), 1.95 (s, 3H,
CH3CON); Selected 13C NMR data (CDCl3): d 101.62 (C-1III), 98.14
(2C-1), 97.50 (C-1), 61.15 (C-6IV), 54.85 (C-2), 54.75 (C-2), 54.67
(C-2), 54.47 (C-2), 38.05 (CH2CH2CH2N), 29.52 (CH2CH2CH2N),
23.23 (CH3CON). HRESIMS: found m/z 2118.6233 [M+H]+;
D
D
D-
D
D
D
C117H100N5O34 2118.6244.
D
D
3.17. 3-(Benzyloxycarbonylamino)propyl 6-O-acetyl-3,4-di-O-
benzoyl-2-deoxy-2-phthalimido-b- -glucopyranosyl-(1?6)-2-
acetamido-3,4-di-O-benzoyl-2-deoxy-b- -glucopyranosyl-
(1?6)-3,4-di-O-benzoyl-2-deoxy-2-phthalimido-b-
glucopyranosyl-(1?6)-3,4-di-O-benzoyl-2-deoxy-2-
phthalimido-b- -glucopyranosyl-(1?6)-3,4-di-O-benzoyl-2-
deoxy-2-phthalimido-b- -glucopyranosyl-(1?6)-2-acetamido-
3,4-di-O-benzoyl-2-deoxy-b- -glucopyranosyl-(1?6)-3,4-di-O-
benzoyl-2-deoxy-2-phthalimido-b- -glucopyranosyl-(1?6)-3,4-
di-O-benzoyl-2-deoxy-2-phthalimido-b- -glucopyranosyl-
(1?6)-3,4-di-O-benzoyl-2-deoxy-2-phthalimido-b-D-
glucopyranoside (31)
D
D
D-
Glycosyl acceptor 30 (52 mg, 0.018 mmol) was allowed to react
with donor 16 (40 mg, 0.022 mmol) as described in Section 3.3 to
give nonasaccharide 31 (25 mg, 33%). [a]D +20 (c1, CHCl3). Selected
D
1H NMR data (CDCl3): d 6.43 (d, 1H, JNH,2 8.8 Hz, NH), 6.38 (d, 1H,
JNH,2 8.8 Hz, NH), 6.28–6.02 (m, 7H, 7H-3), 5.65 (d, 1H, J1,2 8.3 Hz,
H-1), 5.62 (d, 1H, J1,2 8.3 Hz, H-1), 5.00 (s, 2H, CH2Ph), 3.04 (m,
2H, OCH2CH2CH2N), 1.98 (s, 3H, CH3CON), 1.90 (s, 3H, CH3CON),
1.88 (s, 3H, CH3COO), 1.52 (m, 2H, OCH2CH2CH2N); Selected 13C
NMR data (CDCl3): d 102.02 (C-1), 101.79 (C-1), 98.16 (2C-1),
98.09 (C-1) 97.92 (2C-1), 97.54 (C-1), 97.27 (C-1), 62.41 (C-6IX),
54.69 (4C-2), 54.61 (2C-2), 54.23 (2C-2), 54.07 (C-2), 38.00
(CH2CH2CH2N), 29.46 (CH2CH2CH2N), 23.11 (2CH3CON), 20.08
D
D
D
D
(1?6)-3,4-di-O-benzoyl-2-deoxy-2-phthalimido-b-D-
glucopyranoside (34)
Hexasaccharide 33 was prepared by the reaction of glycosyl
acceptor 32 (213 mg, 0.09 mmol) with donor 17 (142 mg,
0.122 mmol) as described in Section 3.3 with subsequent deacety-
lation as described in Section 3.2 (138 mg, 55% for two stages). Se-
lected 1H NMR data (CDCl3): d 6.55 (d, 1H, JNH,2 8.9 Hz, NH), 6.28–
6.16 (m, 5H, 5 H-3), 5.04 (s, 2H, CH2Ph), 4.58–4.40 (m, 3H, 2H-2, H-
1III), 4.37–4.21 (m, 3H, 3H-2), 3.10 (m, 2H, OCH2CH2CH2N), 1.90 (s,
3H, NCOCH3), 1.50 (m, 2H, OCH2CH2CH2N); Selected 13C NMR data
(CDCl3):101.91 (C-1III), 98.06 (2C-1), 97.90 (2C-1), 97.28 (C-1),
61.18 (C-6VI), 54.77 (4C-2), 54.42 (C-2), 54.03 (C-2), 38.00
(CH2CH2CH2N), 29.36 (CH2CH2CH2N), 23,18 (CH3CON).
(CH3COO). HRESIMS: found m/z 2301.6615 [M+2NH4]2+
253H214N12O74 2301.6670.
;
C
3.15. 3-Acetamidopropyl 2-amino-2-deoxy-b-
(1?6)-2-acetamido-2-deoxy-b- -glucopyranosyl-(1?6)-2-
amino-2-deoxy-b- -glucopyranosyl-(1?6)-2-amino-2-deoxy-b-
-glucopyranosyl-(1?6)-2-amino-2-deoxy-b- -glucopyranosyl-
(1?6)-2-acetamido-2-deoxy-b- -glucopyranosyl-(1?6)-2-
amino-2-deoxy-b- -glucopyranosyl-(1?6)-2-amino-2-deoxy-b-
-glucopyranosyl-(1?6)-2-amino-2-deoxy-b- -glucopyranoside
(3)
D-glucopyranosyl-
D
D
D
D
D
The reaction of glycosyl acceptor 33 (138 mg, 0.044 mmol) with
glycosyl donor 16 (80.5 mg, 0.053 mmol) as described in Section
D
D
D
3.3 afforded nonasaccharide 34 (25.6 mg, 19%). [
a]
+18.6 (c 1,
D
CHC13). Selected 1H NMR data (CDCl3): d 6.42 (d, 1H, JNH,2 8.8 Hz,
NH), 6.31 (d, 1H, JNH,2 8.8 Hz, NH), 6.28–6.02 (m, 7H, 7H-3), 5.65
(d, 1H, J1,2 8.3 Hz, H-1), 5.62 (d, 1H, J1,2 8.3 Hz, H-1), 5.00 (s, 2H,
CH2Ph), 3.04 (m, 2H, OCH2CH2CH2N), 2.00 (s, 3H, CH3CON), 1.83
(s, 3H, CH3CON), 1.80 (s, 3H, CH3COO), 1.52 (m, 2H,
OCH2CH2CH2N); Selected 13C NMR data (CDCl3): d 101.92 (C-1II,
C-1VII), 98.16 (3C-1), 97.92 (2C-1), 97.54, (2C-1), 62.50 (C-6IX),
54.78 (7C-2), 54.46 (2C-2), 38.02 (CH2CH2CH2N), 29.47
(CH2CH2CH2N) 22.97 (2 CH3CON), 21.32 (CH3COO). HRESIMS:
found m/z 2301.6628 [M+2NH4]2+; C253H214N12O74 2301.6670.
Compound 31 (21 mg, 0.005 mmol) was deprotected as de-
scribed in Section 3.4 to give 3 (5.5 mg, 66%). 1H NMR (D2O): d
4.81–4.66 (m, 7H, 7H-1), 4.61–4.56 (m, 2H, 2H-1), 4.33–4.21 (m,
8H), 4.01–3.86 (m, 9H), 3.84–3.62 (m, 25H), 3.62–3.49 (m, 10H),
3.49–3.41 (m, 2H), 3.38–3.22 (m, 2H), 2.96–3.10 (m, 7H, 7H-2),
2.10 (s, 6H, 2CH3CON), 2.01 (s, 3H, CH3CON), 1.96 (s, 21H,
CH3COOH), 1.85 (m, 2H, OCH2CH2CH2N); 13C NMR (D2O): 103.33
(C-1), 103.21 (C-1), 101.72 (3C-1), 101.57 (C-1), 101.42 (C-1),
101.16 (C-1), 100.93 (C-1), 77.71, 76.43, 76.24, 76.04, 75.88,
75.04, 74.98, 74.19, 74.05, 73.94, 73.75, 71.21, 71.14, 71.03,
70.05, 69.93, 69.72, 69.42, 61.91 (C-6IX), 57.25 (7C-2), 56.88 (2C-
2), 37.63 (CH2CH2CH2N), 29.95 (CH2CH2CH2N), 24.57, 23.82,
23.46 (3CH3CON). HRESIMS: found m/z 1650.720 [M+H]+; calcd
for C63H115N10O40 1650.719.
3.18. 3-Acetamidopropyl 2-amino-2-deoxy-b-
(1?6)-2-acetamido-2-deoxy-b- -glucopyranosyl-(1?6)-2-
amino-2-deoxy-b- -glucopyranosyl-(1?6)-2-amino-2-deoxy-b-
-glucopyranosyl-(1?6)-2-amino-2-deoxy-b- -glucopyranosyl-
(1?6)-2-amino-2-deoxy-b- -glucopyranosyl-(1?6)-2-
acetamido-2-deoxy-b- -glucopyranosyl-(1?6)-2-amino-2-
deoxy-b- -glucopyranosyl-(1?6)-2-amino-2-deoxy-b-
glucopyranoside (4)
D-glucopyranosyl-
D
D
D
D
D
D
D
D-
3.16. 3-(Benzyloxycarbonylamino)propyl 3,4-di-O-benzoyl-2-
deoxy-2-phthalimido-b-
3,4-di-O-benzoyl-2-deoxy-b-
benzoyl-2-deoxy-2-phthalimido-b-
di-O-benzoyl-2-deoxy-2-phthalimido-b-
D
-glucopyranosyl-(1?6)-2-acetamido-
-glucopyranosyl-(1?6)-3,4-di-O-
-glucopyranosyl-(1?6)-3,4-
-glucopyranoside (32)
D
Compound 34 (30 mg, 0.007 mmol) was deprotected as de-
scribed in Section 3.4 to give 4 (8 mg, 75%). 1H NMR (D2O): d
4.78–4.64 (m, 7H, 7H-1), 4.58–4.52 (m, 2H, 2 H-1), 4.30–4.16 (m,
7H), 3.97–3.83 (m, 8H), 3.80–3.34 (m, 36H), 3.33–3.17 (m, 2H),
3.10–2.92 (m, 7H, 7 H-2), 2.07 (s, 6H, 2CH3CON), 1.98 (s, 3H,
CH3CON), 1.92 (s, 21H, CH3COOH), 1.77 (m, 2H, OCH2CH2CH2N).
HRESIMS: found m/z 1650.719 [M+H]+; calcd for C63H115N10O40
1650.719.
D
D
Tetrasaccharide 32 was prepared by the reaction of glycosyl
acceptor 25 (159 mg, 0.225 mmol) with donor 16 (367. mg,
0.242 mmol) as described in Section 3.3 with subsequent deacety-
lation as described in Section 3.2 (300 mg, 67% for two stages).
Selected 1H NMR data (CDCl3): d 6.34 (d, 1H, JNH,2 8.8 Hz, NH),

O. N. Yudina et al. / Carbohydrate Research 346 (2011) 905–913
913
3.19. 3-(Benzyloxycarbonylamino)propyl 3,4-di-O-benzoyl-2-
deoxy-2-phthalimido-b- -glucopyranosyl-(1?6)-3,4-di-O-
benzoyl-2-deoxy-2-phthalimido-b- -glucopyranosyl-(1?6)-3,4-
di-O-benzoyl-2-deoxy-2-phthalimido-b- -glucopyranosyl-
(1?6)-3,4-di-O-benzoyl-2-deoxy-2-phthalimido-b-
glucopyranosyl-(1?6)-2-acetamido-3,4-di-O-benzoyl-2-deoxy-
b- -glucopyranosyl-(1?6)-3,4-di-O-benzoyl-2-deoxy-2-
phthalimido-b- -glucopyranoside (36)
(s, 2H, CH2Ph), 3.10 (m, 2H, OCH2CH2CH2N), 1.98 (s, 3H, CH3CON),
1.92 (s, 3H, CH3CON), 1.89 (s, 3H, CH3COO). Selected 13C NMR data
(CDCl3): 101.84 (C-1II, C-1VIII), 97.91 (2C-1), 97.82 (3C-1), 97.51 (C-
1) 97.37 (C-1), 62.46 (C-6IX), 54.78 (7C-2), 54.22 (2C-2), 38.01
(CH2CH2CH2N), 29.33 (CH2CH2CH2N), 23.09, 21.41 (2 CH3CON),
D
D
D
D
-
20.53 (CH3COO). HRESIMS: found m/z 2301.6736 [M+2NH4]2+
;
D
C253H206N10O74 2301.6670.
D
3.21. 3-Acetamidopropyl 2-amino-2-deoxy-b-
(1?6)-2-acetamido-2-deoxy-b- -glucopyranosyl-(1?6)-2-
amino-2-deoxy-b- -glucopyranosyl-(1?6)-2-amino-2-deoxy-b-
-glucopyranosyl-(1?6)-2-amino-2-deoxy-b- -glucopyranosyl-
(1?6)-2-amino-2-deoxy-b- -glucopyranosyl-(1?6)-2-amino-2-
deoxy-b- -glucopyranosyl-(1?6)-2-acetamido-2-deoxy-b-
D-glucopyranosyl-
Reaction of glycosyl acceptor 20 (250 mg, 0.165 mmol) with
glycosyl donor 16 (31.5 mg, 0.15 mmol) according to general pro-
cedure 3.3 with subsequent deacetylation according to 3.2 afforded
D
D
D
D
trisaccharide 35 (170 mg, 64% for two stages). [
a]
+1.5 (c 1,
D
D
CHC13). 1H NMR (CDCl3): d 8.25–7.00 (m, 43H, Ar), 6.25–6.15 (m,
2H, H-3I, H-3III), 6.11 (d, 1H, JNH,2 8.3 Hz, NH), 5.58–5.54 (m, 4H,
2 H-1, H-3II, H-4), 5.34–5.21 (m, 5H, 2 H-4, NHZ), 5.10–4.97 (m,
2H, CH2Ph), 4.59 (d, 1H, J1,2 8.2 Hz, H-1II), 4.50 (dd, 1H, J2,1 9.0 Hz,
J2,3 10.6 Hz, H-2), 4.30 (dd, 1H, J2,1 8.7 Hz, J2,3 10.5 Hz, H-2I),
4.15–3.87 (m, 5H), 3.82–3.52 (m, 7H), 3.18 (m, 2H, OCH2CH2CH2N),
1.88 (s, 3H, CH3CON). Selected 13C NMR data (CDCl3): d 101.16 (C-
1II), 97.98 (C-1), 97.47 (C-1), 74.18, 72.87 (C-5), 71.37, 70.81, 70.18
(C-3), 69.72, 69.67 (C-4), 68.02, 66.73 (C-6), 61.03 (C-6III), 54.52
(3C-2), 37.75 (CH2CH2CH2N), 29.54 (CH2CH2CH2N), 23.06
(CH3CON).
D
D-
glucopyranosyl-(1?6)-2-amino-2-deoxy-b-D-glucopyranoside
(5)
Compound 37 (31 mg, 0.007 mmol) was deprotected as de-
scribed in Section 3.4 to give 5 (9 mg, 83%). Selected 1H NMR data
(D2O): d 4.82–4.74 (m, 7H, 7H-1), 4.62–4.56 (m, 2H, 2H-1), 4.33–
4.19 (m, 7H), 4.00–3.87 (m, 8H), 3.84–3.50 (m, 31H), 3.47–3.42
(m, 2H), 3.38–3.32 (m, 2H), 3.12–2.97 (m, 7H, 7H-2), 2.08 (s, 6H,
2CH3CON), 2.01 (s, 3H, CH3CON), 1.96 (s, 21H, CH3COOH), 1.85
(m, 2H, OCH2CH2CH2N); 13C NMR (D2O): 103.35 (C-1), 102.99 (C-
1), 101.71 (2C-1), 101.56 (2C-1), 101.04 (2C-2), 100.55 (C-1),
77.71, 76.42, 76.28, 76.02, 75.87, 75.03, 74.92, 74.06, 73.83,
73.69, 71.14, 70.10, 69.92, 69.70, 69.09, 61.89 (C-6IX), 57.22 (7C-
2), 56.87 (2C-2), 37.63 (CH2CH2CH2N), 29.85 (CH2CH2CH2N),
24.50, 23.74, 23.44 (3CH3CON). HRESIMS: found m/z 1650.719
[M+H]+; calcd for C63H115N10O40: 1650.719.
Hexasaccharide 36 was prepared by the reaction of glycosyl
acceptor 35 (117 mg, 0.073 mmol) with donor 19 (138 mg,
0.08 mmol) as described in Section 3.3 with subsequent deacetyla-
tion as described in Section 3.2 (64 mg, 27% for two stages). After
replacement of the solvent for the glycosylation reaction with
CH3CN (molecular sieves 3 Å were also used instead of MS 4 Å)
the yield of the reaction rose to 45%. [a]D +2 (c 1, CHC13). Selected
1H NMR data (CDCl3): d 6.39 (d, 1H, JNH,2 8.7 Hz, NH), 6.28–6.16 (m,
2H, 2 H-3), 6.12–6.05 (m, 3H, 3 H-3), 5.59–5.32 (m, 8H, 5 H-1, H-3,
2H-4), 5.26–5.09 (m, 4H, 4H-4), 5.01 (s, 2H, CH2Ph), 4.51–4.40 (m,
2H, H-2, H-1II), 3.10 (m, 2H, OCH2CH2CH2N), 1.90 (s, 3H, CH3CON),
1.50 (m, 2H, OCH2CH2CH2N). Selected 13C NMR data (CDCl3): d
101.74 (C-1II), 98.00 (C-1), 97.58 (3C-1), 97.27 (C-1), 61.20 (C-
6VI), 54.64 (2C-2), 54.55 (2C-2), 54.45 (C-2), 54.10 (C-2), 37.96
(CH2CH2CH2N), 29.55 (CH2CH2CH2N) 23.10 (CH3CON). HRESIMS:
Acknowledgments
We acknowledge a grant from the President of the Russian Fed-
eration to Young Scientists (MK-5544.2010.3) for the financial sup-
port of this work.
References
found m/z 1575.9724 [M+2NH4]2+
; calcd for C173H149N9O50
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3. Itoh, Y.; Rice, J. D.; Goller, C.; Pannuri, A.; Taylor, J.; Meisner, J.; Beveridge, T. J.;
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5. Sloan, G. P.; Love, C. F.; Sukumar, N.; Mishra, M.; Deora, R. J. Bacteriol. 2007, 189,
8270–8276.
6. Choi, A. H. K.; Slamti, L.; Avci, F. Y.; Pier, G. B.; Maira-Litrán, T. J. Bacteriol. 2009,
191, 5953–5963.
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6752–6762.
3.20. 3-(Benzyloxycarbonylamino)propyl 6-O-acetyl-3,4-di-O-
benzoyl-2-deoxy-2-phthalimido-b- -glucopyranosyl-(1?6)-2-
acetamido-3,4-di-O-benzoyl-2-deoxy-b- -glucopyranosyl-
(1?6)-3,4-di-O-benzoyl-2-deoxy-2-phthalimido-b-
glucopyranosyl-(1?6)-3,4-di-O-benzoyl-2-deoxy-2-
phthalimido-b- -glucopyranosyl-(1?6)-3,4-di-O-benzoyl-2-
deoxy-2-phthalimido-b- -glucopyranosyl-(1?6)-3,4-di-O-
benzoyl-2-deoxy-2-phthalimido-b- -glucopyranosyl-(1?6)-3,4-
di-O-benzoyl-2-deoxy-2-phthalimido-b- -glucopyranosyl-
(1?6)-2-acetamido-3,4-di-O-benzoyl-2-deoxy-2-phthalimido-
b- -glucopyranosyl-(1?6)-3,4-di-O-benzoyl-2-deoxy-2-
phthalimido-b- -glucopyranoside (37)
D
D
D
-
D
D
D
D
9. Gening, M. L.; Tsvetkov, Y. E.; Pier, G. B.; Nifantiev, N. E. Carbohydr. Res. 2007,
342, 567–575.
10. Leung, C.; Chibba, A.; Gómez-Biagi, R. F.; Nitz, M. Carbohydr. Res. 2009, 344,
570–575.
D
D
11. Handbook of Chemical Glycosylation: Advance in Stereoselectivity and Therapeutic
Relevance; Demchenko, A. V., Ed.; Wiley-VCH, 2008; p 13. pp 457–458.
12. Gening, M. L.; Tsvetkov, Y. E.; Pier, G. B.; Nifantiev, N. E. Russ. J. Bioorg. Chem.
2006, 32, 1–12.
13. Crich, D.; Dudkin, V. J. Am. Chem. Soc. 2001, 123, 6819–6825.
14. Crich, D.; Vinod, A. U. J. Org. Chem. 2005, 70, 1291–1296.
15. Lucas, R.; Hamza, D.; Lubineau, A.; Bonnaffe, D. Eur. J. Org. Chem. 2004, 2107–
2117.
Reaction of glycosyl acceptor 36 (85 mg, 0.027 mmol) with gly-
cosyl donor 16 (54 mg, 0.035 mmol) as described in Section 3.3
yielded nonasaccharide 37 (43.7 mg, 35%). [
a
]
D
+18 (c 1, CHC13).
Selected 1H NMR data (CDCl3): d 6.47 (d, 1H, JNH,2 8.7 Hz, NH),
6.35 (d, 1H, JNH,2 8.6 Hz, NH), 6.28–6.02 (m, 7H, 7H-3), 5.66–5.32
(m, 12H, 7H-1, 2H-3, 3H-4), 5.28–5.09 (m, 7H, 6H-4, NHZ), 4.98