Synthesis of 3,6-branched arabinogalactan-type tetra- and hexasaccharides for characterization of monoclonal antibodies

Article abstract of DOI:10.1016/j.carres.2009.04.025

Synthesis of tetra- and hexasaccharides built up from a β-(1→6)-linked galactopyranosyl backbone with arabinofuranosyl side chains at position 3 and with a 3-aminopropyl spacer related to arabinogalactans is described. These oligosaccharides were prepared

Full text of DOI:10.1016/j.carres.2009.04.025

Carbohydrate Research 344 (2009) 1434–1441
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Carbohydrate Research
journal homepage: www.elsevier.com/locate/carres
Synthesis of 3,6-branched arabinogalactan-type tetra- and hexasaccharides
for characterization of monoclonal antibodies
Anikó Fekete a, Anikó Borbás a, Sándor Antus a,b, András Lipták a,c,
*
a Research Group for Carbohydrates of the Hungarian Academy of Sciences, H-4010, Debrecen, PO Box 94, Hungary
b Department of Organic Chemistry, University of Debrecen, H-4010, Debrecen, PO Box 20, Hungary
c Institute of Biochemistry, University of Debrecen, H-4010, Debrecen, PO Box 55, Hungary
a r t i c l e i n f o
a b s t r a c t
Article history:
Synthesis of tetra- and hexasaccharides built up from a b-(1?6)-linked galactopyranosyl backbone with
arabinofuranosyl side chains at position 3 and with a 3-aminopropyl spacer related to arabinogalactans is
described. These oligosaccharides were prepared for investigation of monoclonal antibodies raised
against arabinogalactan proteins (AGPs) from pressed juice of Echinacea purpurea.
Ó 2009 Elsevier Ltd. All rights reserved.
Received 16 February 2009
Received in revised form 30 March 2009
Accepted 2 April 2009
Available online 3 May 2009
Dedicated to Professor Johannis P.
Kamerling on the occasion of his 65th
birthday
Keywords:
Arabinogalactan proteins
Monoclonal antibodies
Oligosaccharide synthesis
1. Introduction
et al.8 in a competitive ELISA for cross-reactivities. Only one hexa-
saccharide of the synthesized oligosaccharides showed reproduc-
In the last few decades considerable interest has been focussed
upon the molecular nature and architecture of plant cell walls.
Plant cell-wall polysaccharides play an important role in cell–cell
interactions (cell differentiation, growth and development). They
are involved in the interactions of plants with other organisms
and the environment. The use of monoclonal antibodies is one of
the most important tools for plant cell-wall analysis.1 Arabinoga-
lactan-proteins (AGPs) are a class of plant proteoglycans present
in most plant tissues and exudates. They are antigenic and can pro-
duce monoclonal antibodies that are useful for detecting the occur-
rence of a well-defined saccharide sequence in AGPs.2
ible reactivity. This hexasaccharide consists of a tetrameric b-
(1?6)-linked galactan skeleton, with the second and penultimate
galactopyranose units branched at position 2 to an a-linked arabi-
nofuranosyl residue. Classen and co-workers have explained the
weak reactivity of synthetic oligosaccharides with the different
branching modes of the galactosyl units and with the lack of pro-
tein residue.8
For further characterization of these monoclonal antibodies, we
decided to synthesize 3-aminopropyl spacer-containing tetra- and
hexasaccharides consisting of a b-(1?6)-linked galactopyranose
backbone with
a-linked arabinofuranose side chains at position
The AGPs that are components of the high-molecular-weight
fraction of the pressed juice of Echinacea purpurea (the purple
coneflower) have been shown to possess complement-stimulating
activity in vitro, and the carbohydrate portion of these proteogly-
cans consists of mainly 3-, 6- and 3,6-branched galactans with an
3. This hexasaccharide has the same sequence as the above-men-
tioned 2,6-branched hexasaccharide, which shows weak reactivity.
The 3-aminopropyl spacer can ensure conjugation of the synthetic
oligomers to a suitable protein carrier.
a
-linked arabinofuranosyl moiety.3
2. Results and discussion
Earlier we have reported the chemical synthesis of the b-(1?6)-
linked 2-branched arabinogalactan-type series.4–7 These synthetic
oligosaccharides were tested with monoclonal antibodies raised
against AGPs from the pressed juice of E. purpurea by Classen
Preparation of some 3,6-branched arabinogalactan-type
oligosaccharides by a different synthetic strategy has been re-
ported recently.9–13 Our approach was based on the following con-
siderations. The benzoyl group was used as a permanent protecting
group for the secondary hydroxyl functions and as a participating
group ensuring the stereoselective formation of the required
* Corresponding author. Tel.: +36 52 512900/22227; fax: +36 52 512913/22342.
E-mail address: liptaka@puma.unideb.hu (A. Lipták).
0008-6215/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved.
doi:10.1016/j.carres.2009.04.025

A. Fekete et al. / Carbohydrate Research 344 (2009) 1434–1441
1435
OAc
O
OAc
O
OAc
O
AcO
AcO
AcO
AcO
OTr
AcO
AcO
HO
i
ii
O(CH2)3Br
OAc
iii
O
O(CH2)3N3
O(CH2)3N3
HO
OAc
OAc
OAc
OH
1
2
3
4
OH
O
OTr
BzO
BzO
HO
HO
iv
O
O(CH2)3N3
O(CH2)3N3
OBz
5
OH
4
Scheme 1. Reagents and conditions: (i) 3-bromopropanol, BF3ꢀEt2O, DCM, 0 °C?rt, 24 h, 63%; (ii) NaN3, DMF, rt, 24 h, 75%; (iii) (a) NaOMe, MeOH, rt, 24 h; (b) Ph3CCl, DMAP,
Py, rt, 24 h, 68% for two steps; (iv) (a) benzoyl chloride, Py, 0 °C?rt, 24 h; (b) 80% aq acetic acid, 50 °C, 3 h, 76% for 5 for two steps.
b-interglycosidic linkage. The (2-naphthyl)methyl (NAP)14,15 group
was chosen to protect the hydroxyl group at position 3 on the cor-
responding galactopyranoside unit, since it can be easily removed
by oxidative cleavage16 before formation of the arabinofuranosyl
side chain. The primary hydroxyl position was masked with an
acetyl group as a selectively removable protecting group, and thio-
phenyl was used as the anomeric leaving group. Finally, a 3-azido-
propyl aglycon was selected as a marked 3-aminopropyl moiety.
First, the 3-azidopropyl group was introduced in the following
cleavage in the presence of DDQ.18 It is worth mentioning that
the NAP group, like the benzyl group, can be removed by catalytic
hydrogenation, but we used oxidative cleavage to avoid reduction
of the azido function. The resulting acceptor 17 was glycosylated
with the known 2,3,5-tri-O-benzoyl-a-L-arabinofuranosyl bromide
(15)20 using AgOTf activation to afford trisaccharide 16 in 81%
yield. Deacetylation of compound 16 by acid hydrolysis applying
AcCl in MeOH–DCM, followed by condensation of trisaccharide
acceptor 17 with the perbenzoylated donor 11 afforded tetrasac-
charide 18 (Scheme 3).
way: b-D-galactopyranose peracetate (1) was coupled with com-
mercially available 3-bromopropanol in a BF3ꢀEt2O-catalyzed reac-
tion,17 and then the bromo compound 2 was treated with NaN3 in
DMF. After deacetylation of 3, the primary hydroxyl group was
tritylated to afford the triol 4 in moderate yield. Then benzoylation
of compound 4, followed by removal of trityl group by acid hydro-
lysis, gave the spacer-containing acceptor 5 in 77% yield (Scheme
1).
Preparation of hexasaccharide 23 was planned via a 3+3 block
synthesis. Therefore, the synthesis of trisaccharide donor 22 was
first achieved. Thiophenyl glycoside 10 was converted into glycosyl
bromide with bromine and subsequently coupled with the glycosyl
acceptor 12 using AgOTf activation. After oxidative cleavage of the
NAP group with DDQ, the resulting acceptor 21 was arabinofur-
anosylated to give the intended trisaccharide 22 in 85% yield. Next,
the trisaccharide acceptor 17 was glycosylated with the donor 22
using NIS/AgOTf promotion to furnish the fully protected hexasac-
charide 23 (Scheme 4).
Deblocking of the tetra- and hexasaccharides 18 and 23 was ef-
fected in two steps. First, the acyl groups were removed by
Zemplén transesterification, then the azido group was reduced by
catalytic hydrogenation to give the target 3-aminopropyl spacer
containing the tetra- and hexasaccharides 25 and 27 (Scheme 5.).
All the synthesized compounds were characterized by 1H and 13C
NMR spectroscopy, as well as by MALDI TOF mass spectrometry.
However the resonances in the 1H and 13C NMR spectra of
compounds 18, 23, 26 and 27 were complex and overlapping,
and complete assignments could not be achieved even by 2D
NMR analysis.
The synthesis of the glycosyl donor 10 started with tritylation of
the known phenyl 1-thio-b-D
-galactopyranoside (6).18 Our key
reaction was the regioselective alkylation of the triol 7 via dibu-
tylstannylene acetal formation,19 using NAPBr in the presence of
CsF in DMF to afford the building block 8 in 83% yield. Compound
8 was benzoylated, then directly detritylated by acid hydrolysis,
and acetylation of the resulting alcohol 9 provided the thioglyco-
side donor 10. Another galactopyranoside donor 11 was prepared
by perbenzoylation of compound 6. Benzoylation of 7 and subse-
quent acid hydrolysis yielded the acceptor 12 (Scheme 2).
Synthesis of the tetrasaccharide 18 was achieved using the fol-
lowing approach. First, the donor 10 was coupled with the acceptor
5 using NIS/AgOTf promotion to furnish the disaccharide unit 13.
The NAP group of compound 13 was removed with oxidative
OTr
OR
OTr
OH
HO
HO
HO
BzO
HO
HO
O
O
O
O
SPh
SPh
SPh
SPh
i
ii NAPO
iii
NAPO
OH
OH
OBz
OH
6
8
7
9 R = H
iv
v
iii
10 R = OAc
OBz
OH
BzO
BzO
BzO
BzO
O
O
SPh
SPh
OBz
OBz
12
11
Scheme 2. Reagents and conditions: (i) Ph3CCl, DMAP, Py, rt, 24 h, 89%; (ii) (a) Bu2SnO, toluene, reflux temperature, 3 h; (b) NAPBr, CsF, DMF, 24 h, 81% for 8 for two steps;
(iii) (a) benzoyl chloride, Py, 0 °C?rt, 24 h; (b) 80% aq HOAc, 50 °C, 3 h, 73% for 9 for two steps, 84% for 12 for two steps; (iv) Ac2O, Py, rt, 24 h, 95%; (v) benzoyl chloride, Py,
0 °C?rt, 24 h, 95%.

1436
A. Fekete et al. / Carbohydrate Research 344 (2009) 1434–1441
Br
O
OBz
OR
OAc
O
BzO
O
BzO
RO
O
BzO
10
i
5
O
OBz
O
15
iii
BzO
O
OBz
BzO
OBz
O
OBz
O
O(CH2)3N3
O(CH2)3N3
BzO
BzO
BzO
OBz
OBz
OBz
13 R = NAP
14 R = H
ii
16 R = Ac
17 R = H
iv
OBz
BzO
BzO
O
i
11
O
O
BzO
O
OBz
O
O
OBz
BzO
OBz
O
O(CH2)3N3
BzO
BzO
OBz
18
OBz
Scheme 3. Reagents and conditions: (i) NIS in THF, AgOTf in toluene, DCM, ꢁ20 °C?rt, 24 h, 76% for 13, 71% for 18; (ii) DDQ, DCM–MeOH, rt, 24 h, 62%; (iii) AgOTf in toluene,
collidine, DCM, ꢁ74 °C?rt, 24 h, 80%; (iv) AcCl, DCM–MeOH, 0 °C?rt, 24 h, 78%.
In conclusion, we developed an efficient synthetic method for
the preparation of the b-(1?6) linked 3-branched tetra- and hexa-
saccharides 25 and 27 with a 3-aminopropyl spacer related to ara-
binogalactans. The synthesized oligosaccharides will be tested
with monoclonal antibodies raised against AGPs from pressed juice
of E. purpurea.
Silica Gel 60 (E. Merck 63–200 mesh). The 1H (360 MHz,
400 MHz and 500 MHz) and 13C NMR (90.54 MHz, 128 MHz and
125.76 MHz) spectra were recorded with Bruker AM-360, Bruker
DRX-400 and Bruker DRX-500 spectrometers. Internal references:
TMS (0.000 ppm for 1H), CDCl3 (77.00 ppm for 13C for organic solu-
tions). MALDI-TOF MS analyses of compounds were carried out in
the positive reflecton mode using a BIFLEX III mass spectrometer.
3. Experimental
3.2. 3-Bromopropyl 2,3,4,6-tetra-O-acetyl-b-D-galactopyranoside
(2)
3.1. General procedures
To a solution of 1,2,3,4,6-penta-O-acetyl-b-
(1) (1 g, 2.56 mmol) in dry CH2Cl2 (10 mL) were added 3-bromo-
1-propanol (448 L, 5.12 mmol)
D-galactopyranose
Optical rotations were measured at room temperature with a
Perkin–Elmer 241 automatic polarimeter in CHCl3. TLC was per-
formed on Kieselgel 60 F254 (E. Merck) with detection by charring
with 50% aq H2SO4. Column chromatography was performed on
l
L, 5.12 mmol) and BF3ꢀEt2O (643
l
at 0 °C. Then the reaction mixture was left to attain room
OAc
OAc
BzO
OAc
O
BzO
RO
BzO
O
O
i
12
ii
15
ii
O
O
10
O
BzO
BzO
BzO
NAPO
O
OBz
OBz
OBz
O
O
OBz
SPh
SPh
19
Br
BzO
BzO
OBz
OBz
20 R = NAP
21 R = H
OBz
22
iii
OAc
O
BzO
iv 17
O
O
BzO
O
OBz
OBz
O
O
BzO
BzO
BzO
O
OBz
OBz
O
O
BzO
BzO
O
OBz
OBz
O
O(CH2)3N3
BzO
OBz
23
OBz
Scheme 4. Reagents and conditions: (i) Br2, DCM, rt, 1 h; (ii) AgOTf in toluene; collidine, DCM, ꢁ74 °C?rt, 24 h, 74% for 20 for two steps, 83% for 22; (iii) DDQ, DCM–MeOH, rt,
24 h, 76%; (iv) NIS in THF, AgOTf in toluene, DCM, ꢁ20 °C?rt, 24 h, 75%.

A. Fekete et al. / Carbohydrate Research 344 (2009) 1434–1441
1437
OH
OH
HO
O
O
OH
i
OH
O
18
O
O
O
OH
OH
O
OH
O(CH2)3R
HO
24 R = N3
25 R = NH2
HO
O
OH
OH
ii
OH
OH
O
O
O
OH
O
OH
OH
O
OH
HO
HO
i
O
23
OH
OH
O
O
OH
O
O
OH
OH
O(CH2)3R
HO
HO
OH
OH
26 R = N3
ii
27 R = NH2
Scheme 5. Reagents and conditions: (i) NaOMe, DCM–MeOH, 81% for 24, 96% for 26; (ii) H2, Pd/C, H2O, 82% for 25, 86% for 27.
temperature and was stirred overnight. The mixture was diluted
with CH2Cl2, washed with water and satd aq NaHCO3, dried and
concentrated. The crude product was purified by column chroma-
tography (7:3 hexane–EtOAc) to yield 2 (750 g, 63%) as a colourless
3.4. 3-Azidopropyl 6-O-trityl-b-D-galactopyranoside (4)
To a solution of compound 3 (4 g, 9.3 mmol) in MeOH (100 mL)
was added a catalytic amount of NaOMe (pH ꢂ8). After stirring for
1 d at room temperature, the mixture was neutralized with Amber-
lite IR-120 H+ ion-exchange resin, filtered and concentrated. The
product thus obtained was used in the next step without further
purification. To a solution of the crude product (9.3 mmol) in pyr-
idine (50 mL) were added Ph3CCl (6.5 g, 23.3 mmol) and DMAP
(100 mg, 0.82 mmol). After stirring for 1 d at room temperature,
the mixture was concentrated. The residue was diluted with
CH2Cl2 washed with satd aq NaHCO3 dried and concentrated. The
crude product was purified by column chromatography (4:1
DCM–acetone, 0.5% Et3N) to yield 4 (3.2 g, 68%) as a colourless syr-
syrup. [a]
+6.6 (c 0.17 in CHCl3); 1H NMR (CDCl3): d 5.38 (d, 1H,
D
J3,4 3 Hz, H-4), 5.18 (t, 1H, J1,2 8 Hz, J2,3 8 Hz, H-2), 5.02 (dd, 1H,
J2,3 8 Hz, J3,4 3 Hz, H-3), 4.45 (d, 1H, J1,2 8 Hz, H-1), 4.20–4.09 (m,
2H), 3.99 (dd, 1H, J 10 Hz, J 5 Hz), 3.91 (t, 1H, J 5 Hz), 3.71–3.65
(m, 1H, H-5), 3.47 (t, 2H, J 8 Hz, CH2), 2.21–2.13 (m, 2H, CH2),
2.13, 2.07, 2.04, 1.97 (4s, 12H, 4 COCH3); 13C NMR (CDCl3): d
170.26, 170.11, 169.99 and 169.42 (4 CO), 101.45 (C-1), 70.74,
70.59, 68.75 and 66.93 (C-2, C-3, C-4, C-5), 67.21 (CH2), 61.18 (C-
6), 32.15 (CH2), 30.06 (CH2), 20.71, 20.57, 20.47 (4 COCH3). MAL-
DI-TOFMS: calcd for C17H25BrO10: 468.06 [M]. Found: 491.14
[M+Na]+; Anal. Calcd for C17H25BrO10: C, 43.51; H, 5.37. Found: C,
43.45; H, 5.62.
up. [
a]
D
ꢁ25.8 (c 0.13 in CHCl3); 1H NMR (CDCl3): d 7.50–7.16 (m,
15H, aromatic), 4.18 (d, 1H, J1,2 8 Hz, H-1), 3.99–3.90 (m, 2H), 3.87
(br s, 1H, OH), 3.71 (br s, 1H, OH), 3.67–3.58 (m, 2H), 3.55–3.48 (m,
2H), 3.47–3.28 (m, 4H), 3.01 (br s, 1H, OH), 1.94–1.78 (m, 2H, CH2);
13C NMR (CDCl3): d 143.63 (Cq), 103.08 (C-1), 86.83 (Cq), 73.59,
71.61 and 69.05 (C-2, C-3, C-4, C-5), 66.60 (CH2), 62.49 (C-6),
48.25 (CH2), 28.98 (CH2). MALDI-TOFMS: calcd for C28H31N3O6:
505.22 [M]. Found: 528.31 [M+Na]+; Anal. Calcd for C28H31N3O6:
C, 66.52; H, 6.18. Found: C, 66.35; H, 6.39.
3.3. 3-Azidopropyl 2,3,4,6-tetra-O-acetyl-b-D-galactopyranoside
(3)
To a solution of compound 2 (5.9 g, 12.6 mmol) in dry DMF
(20 mL) was added NaN3 (4.1 g, 63 mmol). After stirring for 1 d
at 60 °C, the reaction mixture was diluted with CH2Cl2, washed
with water and satd aq NaHCO3, dried and concentrated. The crude
product was purified by column chromatography (7:3 hexane–
3.5. 3-Azidopropyl 2,3,4-tri-O-benzoyl-b-D-galactopyranoside (5)
EtOAc) to yield 3 (4.1 g, 75%) as a colourless syrup. [
a
]
ꢁ4.4 (c
D
0.18 in CHCl3); 1H NMR (CDCl3): d 5.40 (dd, 1H, J3,4 3 Hz, J4,5
1 Hz, H-4), 5.20 (dd, 1H, J1,2 8 Hz, J2,3 10 Hz, H-2), 5.02 (dd, 1H,
J2,3 10 Hz, J3,4 3 Hz, H-3), 4.48 (d, 1H, J1,2 8 Hz, H-1), 4.26–4.08
(m, 2H), 4.01–3.89 (m, 2H), 3.65–3.57 (m, 1H), 3.44–3.31 (m,
2H), 2.16, 2.07, 2.06, 1.99 (4s, 12H, 4 COCH3), 1.96–1.75 (m, 2H,
CH2); 13C NMR (CDCl3): d 170.32, 170.17, 170.07 and 169.37 (4
CO), 101.25 (C-1), 70.79, 70.60, 68.74 and 66.93 (C-2, C-3, C-4, C-
5), 66.39 (CH2), 61.20 (C-6), 47.83 (CH2), 28.88 (CH2), 20.62 (4
COCH3). MALDI-TOFMS: calcd for C17H25N3O10: 431.15 [M]. Found:
454.33 [M+Na]+; Anal. Calcd for C17H25N3O10: C, 47.33; H, 5.84.
Found: C, 47.51; H, 5.73.
To a solution of compound 4 (3 g, 5.94 mmol) in pyridine
(30 mL) was added benzoyl bromide (3.11 mL, 26.8 mmol) at
0 °C. The reaction mixture was left to attain room temperature
with stirring overnight; it was then concentrated. Toluene was
added to and evaporated from the residue. The residue was diluted
with CH2Cl2, extracted with aq 1 M HCl and satd aq NaHCO3, dried
and concentrated. A solution of crude product (5.94 mmol) in 80%
aq HOAc (100 mL) was stirred at 50 °C for 3 h and the mixture was
then concentrated. Toluene was added to and evaporated from the
residue. The crude product was purified by column chromatogra-
phy (3:2 hexane–EtOAc) to yield 5 (2.6 g, 76%) as a colourless

1438
A. Fekete et al. / Carbohydrate Research 344 (2009) 1434–1441
syrup. [
a
]
+176.4 (c 0.12 in CHCl3); 1H NMR (CDCl3): d 8.28–7.14
and 165.11 (2 CO), 85.69 (C-1), 77.73, 77.18, 69.48 and 66.96 (C-
2, C-3, C-4, C-5), 70.79 (CH2), 60.81 (C-6). MALDI-TOFMS: calcd
for C37H32O7S: 620.19 [M]. Found: 643.35 [M+Na]+; Anal. Calcd
for C37H32O7S: C, 71.59; H, 5.20. Found: C, 71.38; H, 5.59.
D
(m, 15H, aromatic), 5.87–5.78 (m, 2H, H-4, H-2), 5.61 (dd, 1H, J2,3
10 Hz, J3,4 3 Hz, H-3), 4.81 (d, 1H, J1,2 8 Hz, H-1), 4.10–3.98 (m,
2H), 3.88–3.79 (m, 1H), 3.74–3.57 (m, 2H), 3.35–3.16 (m, 2H),
2.86 (br s, 1H, OH), 1.92–1.68 (m, 2H, CH2); 13C NMR (CDCl3): d
166.65, 165.47 and 165.30 (3 CO), 101.60 (C-1), 74.01, 71.70,
69.88 and 68.86 (C-2, C-3, C-4, C-5), 60.52 (C-6), 66.63, 47.73 and
28.88 (3 CH2). MALDI-TOFMS: calcd for C30H29N3O9: 575.19 [M].
Found: 598.31 [M+Na]+; Anal. Calcd for C30H29N3O9: C, 62.60; H,
5.08. Found: C, 62.85; H, 5.23.
3.9. Phenyl 6-O-acetyl-2,4-di-O-benzoyl-3-O-(2-naphthylmethyl)-
1-thio-b-D-galactopyranoside (10)
To a solution of compound 9 (160 mg, 0.26 mmol) in pyridine
(10 mL) was added Ac2O (5 mL). After stirring for 2 h at room tem-
perature, the mixture was concentrated. Toluene was added to and
evaporated from the residue. The residue was diluted with CH2Cl2,
extracted with aq 1 M HCl and satd aq NaHCO3, dried and concen-
trated. The crude product was purified by column chromatography
(7:3 hexane–EtOAc) to yield 10 (164 g, 95%) as a colourless syrup.
3.6. Phenyl 6-O-trityl-1-thio-b-
D-galactopyranoside (7)
To a solution of phenyl 1-thio-b-
D
-galactopyranoside (6)18
(4.2 g, 15.44 mmol) in pyridine (50 mL) were added Ph3CCl
(10.8 g, 38.72 mmol) and DMAP (100 mg, 0.82 mmol). After stirring
for 1 d at room temperature, the mixture was concentrated. The
residue was dissolved in toluene and evaporated. The residue
was diluted with CH2Cl2, extracted with satd aq NaHCO3, dried
and concentrated. The crude product was purified by column chro-
matography (4:1 CH2Cl2–acetone, 0.5% Et3N) to yield 7 (7.1 g, 90%)
[a]
D +68.6 (c 0.14 in CHCl3); 1H NMR (CDCl3): d 7.97–7.14 (m, 22H,
aromatic), 5.87 (d, 1H, J3,4 3 Hz, H-4), 5.49 (t, 1H, J1,2 10 Hz, J2,3
10 Hz, H-2), 4.82 (d, 1H, J 13 Hz, CHa), 4.77 (d, 1H, J1,2 10 Hz, H-
1), 4.62 (d, 1H, J 13 Hz, CHb), 4.29–4.21 (m, 2H), 4.00 (t, 1H,
J = 6 Hz), 3.84 (dd, 1H, J2,3 10 Hz, J3,4 3 Hz, H-3), 2.06 (s, 3H, COCH3);
13C NMR (CDCl3): d 170.52, 165.72 and 165.06 (3 CO), 85.51 (C-1),
77.15, 75.06, 69.30 and 66.58 (C-2, C-3, C-4, C-5), 70.92 (CH2),
62.62 (C-6) 20.72 (COCH3). MALDI-TOFMS: calcd for C39H34O8S:
662.20 [M]. Found: 685.37 [M+Na]+; Anal. Calcd for C39H34O8S: C,
70.68; H, 5.17. Found: C, 70.83; H, 5.41.
as a colourless syrup. [
a
]
D ꢁ13.9 (c 0.15 in CHCl3); 1H NMR (CDCl3):
d 7.61–7.11 (m, 20H, aromatic), 4.55 (d, 1H, J1,2 8 Hz, H-1), 4.17 (br
s, 1H, OH), 3.93 (br s, 1H, OH), 3.81 (d, 1H, J3,4 3 Hz, H-4), 3.71 (t,
1H, J1,2 10 Hz, J2,3 10 Hz, H-2), 3.56–3.44 (m, 3H, H-5, H-6a, H-6b),
3.29 (br s, 1H, OH), 3.25 (dd, 1H, J2,3 10 Hz, J3,4 3 Hz, H-3); 13C
NMR (CDCl3): d 13C NMR (CDCl3): d 143.65 (Cq), 88.52 (C-1),
86.85 (Cq), 77.71, 74.83, 69.79 and 69.66 (C-2, C-3, C-4, C-5),
63.61 (C-6). MALDI-TOFMS: calcd for C31H30O5S: 514.18 [M].
Found: 537.34 [M+Na]+; Anal. Calcd for C31H30O5S: C, 72.35; H,
5.88. Found: C, 72.14; H, 5.69.
3.10. Phenyl 2,3,4,6-tetra-O-benzoyl-1-thio-b-D-
galactopyranoside (11)
To a solution of compound 6 (1 g, 3.68 mmol) in pyridine
(30 mL) was added benzoyl bromide (2.55 mL, 22 mmol) at 0 °C.
The reaction mixture was left to attain room temperature with stir-
ring overnight; it was then concentrated. Toluene was added to
and evaporated from the residue. The residue was diluted with
CH2Cl2, extracted with aq 1 M HCl and satd aq NaHCO3, dried
and concentrated. The crude product was purified by column chro-
matography (4:1 hexane–acetone) to yield 11 (2.4 g, 95%) as a col-
3.7. Phenyl 3-O-(2-naphthylmethyl)-6-O-trityl-1-thio-b-D-
galactopyranoside (8)
To a solution of compound 7 (1 g, 1.9 mmol) in toluene (20 mL)
was added dibutyltin oxide (612 mg, 2.46 mmol). After stirring for
3 h at reflux, the mixture was concentrated. The residue was dis-
solved in dry DMF and CsF (580 mg, 3.8 mmol) and 2-naphthyl-
methyl bromide (840 mg, 3.8 mmol) were added. After stirring
for 1 d the mixture was concentrated. The residue was diluted with
CH2Cl2, extracted with satd aq NaHCO3, dried and concentrated.
The crude product was purified by column chromatography (7:3
hexane–EtOAc, 0.5% Et3N) to yield 8 (1.03 g, 81%) as a colourless
ourless syrup. [a]
D +81.5 (c 0.12 in CHCl3); 1H NMR (CDCl3): d ppm
8.12–7.18 (m, 25H, aromatic), 6.04 (d, 1H, J3,4 3 Hz, H-4), 5.81 (t,
1H, J1,2 10 Hz, J2,3 10 Hz, H-2), 5.65 (dd, 1H, J2,3 10 Hz, J3,4 3 Hz,
H-3), 5.09 (d, 1H, J1,2 10 Hz, H-1), 4.67 (dd, 1H, J 9 Hz, J 5 Hz),
4.54–4.38 (m, 2H); 13C NMR (CDCl3): d 166.02, 165.48, 165.36
and 165.17 (4 CO), 85.81 (C-1), 75.10, 72.94, 68.30 and 67.84 (C-
2, C-3, C-4, C-5), 62.48 (C-6). MALDI-TOFMS: calcd for C40H32O9S:
688.18 [M]. Found: 711.30 [M+Na]+; Anal. Calcd for C40H32O9S: C,
69.75; H, 4.68. Found: C, 69.41; H, 4.32.
syrup. [a]
+1.3 (c 0.15 in CHCl3); 1H NMR (CDCl3): d 7.91–7.11
D
(m, 27H, aromatic), 4.88–4.82 (m, 2H, CH2), 4.49 (d, 1H, J1,2
10 Hz, H-1), 3.95 (br s, 1H, H-4), 3.84 (t, 1H, J1,2 10 Hz, J2,3 10 Hz,
H-2), 3.60–3.26 (m, 3H, H-5, H-6a, H-6b), 2.6 (br s, 2H, OH), 2.52
(dd, 1H, J2,3 8 Hz, J3,4 2 Hz, H-3); 13C NMR (CDCl3): d 143.78 (Cq),
88.54 (C-1), 86.93 (Cq), 81.30, 77.71, 68.93 and 67.33 (C-2, C-3,
C-4, C-5), 72.05 (CH2), 63.65 (C-6). MALDI-TOFMS: calcd for
C42H38O5S: 654.24 [M]. Found: 677.39 [M+Na]+; Anal. Calcd for
C42H38O5S: C, 77.04; H, 5.85. Found: C, 77.32; H, 5.61.
3.11. Phenyl 2,3,4-tri-O-benzoyl-1-thio-b-D-galactopyranoside
(12)
To a solution of compound 7 (2.3 g, 4.47 mmol) in pyridine
(30 mL) was added benzoyl bromide (2.33 mL, 20.1 mmol) at 0 °C
and the mixture was then treated as described for the preparation
of 5. The crude product was purified by column chromatography
(7:3 hexane–EtOAc) to yield 12 (2.2 g, 84%) as a colourless syrup.
3.8. Phenyl 2,4-di-O-benzoyl-3-O-(2-naphthylmethyl)-1-thio-b-
D-galactopyranoside (9)
[a]
+136.3 (c 0.18 in CHCl3); 1H NMR (CDCl3): 8.2–7.2 (m, 20H,
D
To a solution of compound 8 (1 g, 1.53 mmol) in pyridine
aromatic) 5.86 (d, 1H, J3,4 3 Hz, H-4), 5.8 (t, 1H, J1,2 10 Hz, J2,3
10 Hz, H-2), 5.59 (dd, 1H, J2,3 10 Hz, J3,4 3 Hz, H-3), 5.03 (d, 1H,
J1,2 10 Hz, H-1), 4.19–4.03 (m, 1H), 3.94–3.78 (m, 1H), 3.73–3.54
(m, 1H), 2.77–2.63 (br s, 1H, OH); 13C NMR (CDCl3): d 166.46,
165.49 and 165.17 (3 CO), 85.53 (C-1), 77.87, 73.11, 68.89 and
67.95 (C-2, C-3, C-4, C-5), 60.72 (C-6). MALDI-TOFMS: calcd for
C33H28O8S: 584.15 [M]. Found: 607.30 [M+Na]+; Anal. Calcd for
C33H38O8S: C, 67.79; H, 4.83. Found: C, 67.52; H, 4.67.
(20 mL) was added benzoyl bromide (530 lL, 4.57 mmol) at 0 °C
and the mixture was then treated as described for the preparation
of 5. The crude product was purified by column chromatography
(7:3 hexane–EtOAc) to yield 7 (693 g, 73%) as a colourless syrup.
[a
]
D
+62.4 (c 0.16 in CHCl3); 1H NMR (CDCl3): d 8.18–7.05 (m,
22H, aromatic), 5.81 (d, 1H, J3,4 3 Hz, H-4), 5.58 (t, 1H, J1,2 10 Hz,
J2,3 10 Hz, H-2), 4.84–4.73 (m, 2H, CH2), 4.60 (d, 1H, J1,2 10 Hz, H-
1), 3.92–3.75 (m, 3H), 3.60 (m, 1H); 13C NMR (CDCl3): d 166.91

A. Fekete et al. / Carbohydrate Research 344 (2009) 1434–1441
1439
3.12. 3-Azidopropyl 6-O-acetyl-2,4-di-O-benzoyl-3-O-(2-naph-
thylmethyl)-b- -galactopyranosyl-(1?6)-2,3,4-tri-O-benzoyl-b-
-galactopyranoside (13)
was added. The reaction mixture was then left to attain room tem-
perature and was stirred overnight. The mixture was diluted with
CH2Cl2 and filtered through Celite. The filtrate was washed with
10% aq Na2S2O3 and water, dried and concentrated. The crude
product was purified by column chromatography (99:1 CH2Cl2–
D
D
A
solution of donor 10 (960 mg, 1.45 mmol), acceptor 5
(695 mg, 1.21 mmol) and 4 Å molecular sieves in dry CH2Cl2
(10 mL) was cooled to ꢁ20 °C. After stirring for 30 min at ꢁ20 °C,
a mixture of NIS (360 mg, 1.6 mmol) in dry THF (1 mL) and AgOTf
(54 mg, 0.21 mmol) in dry toluene (0.5 mL) was added dropwise.
Then the reaction mixture was left to attain room temperature
overnight. The reaction was quenched with pyridine (0.5 mL), di-
luted with CH2Cl2 and filtered through Celite. The filtrate was
washed with 10% aq Na2S2O3 and water, dried and concentrated.
The crude product was purified by column chromatography (98:2
CH2Cl2–acetone) to yield 13 (1.01 g, 76%) as a colourless syrup.
acetone) to yield 16 (230 mg, 80%) as a colourless syrup. [a] +94
D
(c 0.20 in CHCl3); 1H NMR (CDCl3): d 8.09–7.17 (m, 40H, aromatic),
5.87 (d, 1H, J 3 Hz, H-4), 5.80 (d, 1H, J 3 Hz, H-4I), 5.71 (t, 1H, J
10 Hz, H-2I), 5.69 (t, 1H, J 8 Hz, H-2), 5.53 (dd, 1H, J 10 Hz, J 3 Hz,
H-3), 5.49 (d, 1H, J 6 Hz, H-3II), 5.36 (s, 1H, H-1II), 5.27 (s, 1H, H-
2II), 4.93 (dd, 1H, J 12 Hz, J 3 Hz, 1H, H-5IaI), 4.83–4.79 (m, 1H, H-
4II), 4.72 (d, 1H, J 8 Hz, H-1), 4.67 (dd, 1H, J 12 Hz, J 4 Hz, H-5IbI),
4.64 (d, 1H, J 8 Hz, H-1I), 4.24 (dd, 1H, J 10 Hz, J 3 Hz, H-3I), 4.18
(dd, 1H, J 4, J 8 Hz, H-5I), 4.16–4.08 (m, 3H, H-6a, H-6aI , H-6Ib),
4.03 (t, 1H, J 6 Hz, H-5I), 3.81 (dd, 1H, J 10 Hz, J 8 Hz, H-6b), 3.68–
3.62 (m, 1H, OCHa), 3.34–3.28 (m, 1H, OCHb), 3.08 (t, 2H, J 6 Hz,
CH2), 1.92 (s, 3H, COCH3), 1.62–1.43 (m, 2H, CH2); 13C NMR (CDCl3):
d 170.29, 165.67, 165.56, 165.16 and 164.88 (9 CO), 107.77 (C-1II),
101.25 (C-1 and C-1I), 82.38 (C-2II), 81.53 (C-4II), 77.37 (C-3II),
76.31(C-3I), 73.26 (C-5), 71.53 (C-3), 71.43 (C-2I), 71.38 (C-5I),
69.75 (C-2), 69.58 (C-4I), 68.75 (C-4), 68.16 (C-6), 66.14 (CH2),
63.14 (C-5II), 61.78 (C-6I), 47.66 (CH2), 28.63 (CH2), 20.46 (COCH3).
[
a]
+118 (c 0.12 in CHCl3); 1H NMR (CDCl3): d 8.27–7.18 (m,
D
32H, aromatic), 5.88 (br s, 2H, H-4, H-40), 5.70 (dd, 1H, J 10 Hz, J
8 Hz, H-2), 5.59 (dd, 1H, J 10 Hz, J 8 Hz, 1H, H-2I), 5.54 (dd, 1H,
J2,3 10 Hz, J3,4 3 Hz, H-3), 4.88 (d, 1H, J 13 Hz, ArCHa), 4.68 (d, 1H,
J 13 Hz, ArCHb), 4.65 (d, 1H, J 8 Hz, H-1I), 4.63 (d, 1H, J 8 Hz, H-1),
4.25–4.08 (m, 4H, H-5, H-6I , H-6I , H-6a), 3.95 (t, 1H, J 6 Hz, 1H,
a
b
H-5I), 3.88–3.74 (m, 2H, H-30, H-6b), 3.65–3.57 (m, 1H, CHa),
3.35–3.25 (m, 1H, CHb), 3.06 (t, 2H, J 6 Hz, CH2), 2.01 (s, 3H, COCH3),
1.61–1.37 (m, 2H, CH2); 13C NMR (CDCl3): d 170.42, 165.77, 165.31,
165.18 and 165.00 (6 CO), 101.16 (C-1 and C-1I), 75.77 (C-3I), 73.22
(C-5), 71.50 (C-5I), 71.18 (C-3), 70.93 (C-2I), 69.70 (C-2), 68.71 (C-
4), 66.29 (C-4I), 70.89 (ArCH2), 68.07 (CH2), 66.04 (C-6), 62.08 (C-
6I), 47.62 (CH2), 28.55 (CH2), 20.56 (COCH3). MALDI-TOFMS: calcd
for C63H57N3O17: 1127.37 [M]. Found: 1150.48 [M+Na]+; Anal.
Calcd for C63H57N3O17: C, 67.07; H, 5.09. Found: C, 67.34; H, 5.28.
MALDI-TOFMS: calcd for C78H69N3O24
: 1431.43 [M]. Found:
1454.58 [M+Na]+; Anal. Calcd for C78H69N3O24: C, 65.40; H, 4.86.
Found: C, 65.71; H, 4.57.
3.15. 3-Azidopropyl 2,3,5-tri-O-benzoyl-
(1?3)-2,4-di-O-benzoyl-b- -galactopyranosyl-(1?6)-2,3,4-tri-
O-benzoyl-b- -galactopyranoside (17)
a-L-arabinofuranosyl-
D
D
To a solution of compound 16 (170 mg, 0.12 mmol) in 1:1 DCM–
MeOH (10 mL) was added AcCl (42 L, 0.59 mmol) at 0 °C. The
3.13. 3-Azidopropyl 6-O-acetyl-2,4-di-O-benzoyl-b-
D
-galacto-
l
pyranosyl-(1?6)-2,3,4-tri-O-benzoyl-b- -galactopyranoside (14)
D
reaction mixture was left to attain room temperature with stirring
overnight; it was then concentrated. The residue was purified by
silica column chromatography (98:2 CH2Cl2–acetone) to yield 17
To a solution of compound 13 (420 mg, 0.37 mmol) in 4:1 DCM–
MeOH (25 mL) were added DDQ (134 mg, 0.59 mmol) and a trace
of H2O. After stirring for 1 d, the mixture was evaporated. The res-
idue was diluted with CH2Cl2, extracted with satd aq NaHCO3 and
water, dried and concentrated. The crude product was purified by
silica column chromatography (95:5 CH2Cl2–EtOAc) to yield 14
(120 mg, 72%) as a colourless syrup. [a] +100 (c 0.12 in CHCl3);
D
1H NMR (CDCl3): d 8.10–7.19 (m, 40H, aromatic), 5.89 (d, 1H, J
3 Hz, H-4), 5.76 (d, 1H, J 3 Hz, H-4I), 5.75 (t, 1H, J 8 Hz, H-2I),
5.67 (dd, 1H, J 8, J 10 Hz, H-2), 5.51 (dd, 1H, J 10, J 3 Hz, H-3),
5.42 (d, 1H, J 5 Hz, H-3II), 5.38 (s, 1H, H-1II), 5.26 (s, 1H, H-2II),
4.77 (dd, 1H, J 12 Hz, J 3 Hz, H-5IaI), 4.71 (d, 1H, J 8 Hz, H-1), 4.63
(d, 1H, J 8 Hz, H-1I), 4.56 (dd, 1H, J 13, J 5 Hz, H-5IbI), 4.52–4.48
(m, 1H, H-4II), 4.21 (dd, 1H, J 10 Hz, J 4 Hz, H-3I), 4.15–4.07 (m,
2H, H-5, H-6a), 3.87–3.78 (m, 2H, H-5I, H-6b), 3.73–3.61 (m, 2H,
CHa, H-6I ), 3.50–3.40 (m, 1H, H-6I ), 3.38–3.30 (m, 1H, CHb), 3.09
(228 mg, 62%) as a colourless syrup. [a] +108 (c 0.13 in CHCl3);
D
1H NMR (CDCl3): d 8.22–7.16 (m, 25H, aromatic), 5.86 (d, 1H, J
3 Hz, 1H, H-4), 5.69 (dd, 1H, J 10, J 8 Hz, H-2), 5.61 (d, 1H, J 3 Hz,
1H, H-4I), 5.52 (dd, 1H, J2,3 10, J3,4 3 Hz, H-3), 5.35 (dd, 1H, J
10 Hz, J 8 Hz, H-2I), 4.71 (d, 1H, J 8 Hz, H-1I), 4.65 (d, 1H, J 8 Hz,
H-1), 4.19–4.01 (m, 5H, H-3, H-5, H-6I , H-6I , H-6a), 3.95 (t, 1H, J
a
b
(t, 2H, J 6 Hz, CH2), 2.76 (br s, 1H, OH), 1.64–1.45 (m, 2H, CH2);
13C NMR (CDCl3):
167.11, 166.05, 165.54, 165.48, 165.39,
a
b
6 Hz, H-5I), 3.81 (dd,1H, J 10 Hz, J 8 Hz, H-6b), 3.72–3.65 (m, 1H,
CHa), 3.40–3.31 (m, 1H, CHb), 3.10 (t, 2H, J 6 Hz, CH2), 2.80 (br s,
1H, OH), 1.94 (s, 3H, COCH3), 1.67–1.43 (m, 2H, CH2); 13C NMR
(CDCl3): d 170.44, 166.46, 166.23, 165.40 and 165.24 (6 CO),
101.35 (C-1), 100.82 (C-1I), 73.34 (C-2I), 73.16 (C-3I), 71.59 (C-3,
C-5), 71.26 (C-5I), 70.27 (C-4), 69.75 (C-2), 68.68 (C-4I), 68.08 (C-
6), 66.24 (CH2), 61.97 (C-6I), 47.71 (CH2), 28.71 (CH2), 20.56
d
165.19, 165.09 and 164.70 (8 CO), 107.71 (C-1II), 101.42 (C-1),
101.33 (C-1I), 82.17 (C-2II), 81.82 (C-4II), 77.15 (C-3I), 77.08 (C-
3II), 73.96 (C-5I), 73.16 (C-5), 71.59 (C-4I), 71.34 (C-2I), 70.37 (C-
3), 69.77 (C-2), 68.69 (C-4), 68.23 (C-6), 66.20 (CH2), 63.33 (C-5II),
60.26 (C-6I), 47.71 (CH2), 28.69 (CH2). MALDI-TOFMS: calcd for
C76H67N3O23: 1389.42 [M]. Found: 1412.45 [M+Na]+; Anal. Calcd
for C76H67N3O23: C, 65.65; H, 4.86. Found: C, 65.42; H, 4.47.
(COCH3). MALDI-TOFMS: calcd for C52H49N3O17
: 987.31 [M].
Found: 1010.26 [M+Na]+; Anal. Calcd for C52H49N3O17: C, 63.22;
H, 5.00. Found: C, 63.56; H, 5.33.
3.16. 3-Azidopropyl 2,3,4,6-tetra-O-benzoyl-b-
anosyl-(1?6)-[2,3,5-tri-O-benzoyl- -arabinofuranosyl-(1?3)]-
2,4-di-O-benzoyl-b- -galactopyranosyl-(1?6)-2,3,4-tri-O-
benzoyl-b- -galactopyranoside (18)
D-galactopyr-
a-L
3.14. 3-Azidopropyl 2,3,5-tri-O-benzoyl-
(1?3)-6-O-acetyl-2,4-di-O-benzoyl-b- -galactopyranosyl-
(1?6)-2,3,4-tri-O-benzoyl-b- -galactopyranoside (16)
a
-L
-arabinofuranosyl-
D
D
D
D
A solution of donor 11 (150 mg, 0.22 mmol), acceptor 17
(150 mg, 0.11 mmol) and 4 Å molecular sieves in dry CH2Cl2
(5 mL) was cooled to ꢁ20 °C. After stirring for 30 min at ꢁ20 °C,
To a solution of glycosyl bromide 1520 (154 mg, 0.3 mmol) and
acceptor 14 (200 mg, 0.2 mmol) in dry CH2Cl2 (5 mL) were added
collidine (45
lL, 0.34 mmol) and 4 Å molecular sieves, and the
a mixture of NIS (54 mg, 0.24 mmol) in dry THF (200
l
L) and AgOTf
L) was added dropwise.
Then the mixture was treated as described for the preparation of
mixture was cooled to ꢁ74 °C. After stirring for 30 min at ꢁ74 °C,
(8 mg, 0.03 mmol) in dry toluene (500 l
silver triflate (113 mg, 0.44 mmol) dissolved in toluene (1 mL)

1440
A. Fekete et al. / Carbohydrate Research 344 (2009) 1434–1441
13. The crude product was purified by column chromatography
(97:3 CH2Cl2–EtOAc) to yield 18 (150 mg, 71%) as a colourless syr-
10 Hz, J 3 Hz, H-3), 5.33 (dd, 1H, J 10 Hz, J 8 Hz, H-2I), 4.93 (d,
1H, J 10 Hz, H-1), 4.78 (d, 1H, J 8 Hz, H-1I), 4.29–4.21 (m, 1H, H-
5), 4.17–3.88 (m, 6H, H-3I, H-6a, H-6b, H-6aI , H-6Ib, H-5I), 2.82 (br
s, 1H, OH), 1.97 (s, 3H, COCH3); 13C NMR (CDCl3): d 170.46,
166.98, 166.20, 165.39 and 165.10 (5 CO), 100.89 (C-1I), 85.37
(C-1), 73.60 (C-5), 73.00 (C-3 and C-2I), 71.91 (C-3I), 71.34 (C-5I),
70.22 (C-4I), 68.57 (C-4)and 67.76 (C-2), 67.99 and 61.98 (C-6, C-
6I), 20.63 (COCH3). MALDI-TOFMS: calcd for C55H48O16S: 996.27
[M]. Found: 1019.27 [M+Na]+; Anal. Calcd for C55H48O16S: C,
66.26; H, 4.85. Found: C, 66.45; H, 4.57.
up. [a]
+74.5 (c 0.10 in CHCl3); 1H NMR (CDCl3): d 8.15–7.11 (m,
D
60H, aromatic), 5.89–5.80 (m, 3H, H-4I, H-4III, H-4), 5.74–5.60 (m,
3H, H-2, H-2I, H-2III), 5.56–5.47 (m, 3H, H-3, H-3II, H-3III), 5.30 (s,
1H, H-1II), 5.25 (d, 1H, J 1 Hz, H-2II), 5.07–4.93 (m, 2H, H-5IaI, H-
4II), 4.83–4.68 (m, 1H, H-5IbI), 4.73 (d,1H, J 8 Hz, H-1), 4.62 (d, 1H,
J 8 Hz, H-1I), 4.59 (d, 1H, J 8 Hz, H-1III), 4.19–3.93 (m, 8H, H-3I,
H-5, H-5I, H-5III, H-6a, H-6aI , H-6IaII, H-6bIII), 3.77–3.52 (m, 3H, H-6b,
H-6I , CHa), 3.32–3.24 (m, 1H, CHb), 3.05 (t, 2H, J 7 Hz, CH2), 1.59–
b
1.36 (m, 2H, CH2); 13C NMR (CDCl3): d 166.12, 165.86, 165.73,
165.35, 165.24, 164.97, 164.88 and 164.58 (12 CO), 107.65 (C-1II),
101.30 and 101.22 (C-1I and C-1III), 101.60 (C-1), 82.59 (C-2II),
81.56 (C-4II), 77.58 (C-3II), 76.09 (C-3I), 73.05 and 72.80 (C-5, C-
5I), 71.68, 71.58, 71.40, 69.87, 69.60, 68.79 and 67.79 (C-2, C-2I,
C-2III, C-3, C-3III, C-4, C-4I, C-4III, C-5III), 68.13 (C-6III), 66.38 (C-
5II), 66.17 (CH2), 63.26 and 61.44 (C-6, C-6I), 47.74 (CH2), 28.67
(CH2). MALDI-TOFMS: calcd for C110H93N3O32: 1967.57 [M]. Found:
1990.68 [M+Na]+; Anal. Calcd for C110H93N3O32: C, 67.10; H, 4.76.
Found: C, 67.39; H, 4.47.
3.19. Phenyl 2,3,5-tri-O-benzoyl-
6-O-acetyl-2,4-di-O-benzoyl-b- -galactopyranosyl-(1?6)-2,3,4-
tri-O-benzoyl-1-thio-b- -galactopyranoside (22)
a-L-arabinofuranosyl-(1?3)-
D
D
To a solution of glycosyl bromide 159 (457 mg, 0.89 mmol) and
acceptor 21 (593 mg, 0.6 mmol) in dry CH2Cl2 (10 mL) were added
collidine (134 lL, 1.01 mmol) and 4 Å molecular sieves, and the
mixture was cooled to ꢁ74 °C. After stirring for 30 min at ꢁ74 °C,
silver triflate (365 mg, 1.42 mmol) dissolved in toluene (2 mL)
was added. Then the mixture was treated as described for the
preparation of 16. The crude product was purified by silica column
chromatography (99:1 CH2Cl2–acetone) to yield 22 (720 mg, 83%)
3.17. Phenyl 6-O-acetyl-2,4-di-O-benzoyl-3-O-(2-naphthyl-
methyl)-b-D-galactopyranosyl-(1?6)-2,3,4-tri-O-benzoyl-1-thio-
b-D
-galactopyranoside (20)
as a colourless syrup. [a]
D +82.9 (c 0.12 in CHCl3); 1H NMR (CDCl3):
d 8.09–7.15 (m, 45H, aromatic), 5.88 (d, 1H, J 3 Hz, H-4), 5.79 (d,
1H, J 3 Hz, H-4I), 5.75–5.62 (m, 2H, H-2, H-2I), 5.50–5.45 (m, 2H,
H-3II, H-3), 5.35 (s, 1H, H-1II), 5.28 (s, 1H, H-2II), 4.94 (dd, 1H, J
12 Hz, J 2 Hz, H-5IaI), 4.85 (d, 1H, J 10 Hz, H-1), 4.83–4.78 (m, 1H,
H-4II), 4.77 (d, 1H, J 8 Hz, H-1I), 4.67 (dd, 1H, J 12 Hz, J 4 Hz,
H-5IbI), 4.25–4.17 (m, 2H, H-3I, H-5I), 4.14–3.96 (m, 4H, H-5, H6a,
H-6b, H-6I ), 3.91 (dd, 1H, J 11 Hz, J 7 Hz, H-6I ), 1.94 (s, 3H, COCH3);
To a solution of compound 10 (1.43 g, 2.16 mmol) in dry CH2Cl2
(20 mL) was added bromine (130 lL, 2.53 mmol) at room temper-
ature. After stirring for 1 h, the reaction mixture was concentrated.
Dry toluene was added to and evaporated from the residue to yield
glycosyl bromide 19. To a solution of compound 19 (2.16 mmol)
and acceptor 12 (835 mg, 1.43 mmol) in dry CH2Cl2 (20 mL) were
a
b
added collidine (321
l
L, 2.42 mmol) and 4 Å molecular sieves,
13C NMR (CDCl3): d 170.71, 166.46, 166.08, 165.97, 165.63, 165.39
and 164.95 (9 CO), 108.09 (C-1II), 101.71 (C-1I), 85.59 (C-1), 82.74
(C-2II), 81.96 (C-4II), 77.76 (C-3II), 77.54 (C-3I), 76.77 (C-5I), 73.30
(C-3), 71.92 (C-5), 71.53 (C-2I), 69.95 (C-4I), 68.96 (C-4), 68.10
(C-2), 68.22 (C-6I), 63.53 (C-5II), 62.21 (C-6), 20.91 (COCH3). MAL-
DI-TOFMS: calcd for C81H68O23S: 1440.39 [M]. Found: 1464.44
[M+Na]+; Anal. Calcd for C81H68O23S: C, 67.49; H, 4.75. Found: C,
67.73; H, 4.92.
and the mixture was cooled to ꢁ74 °C. After stirring for 30 min
at ꢁ74 °C, silver triflate (820 mg, 3.19 mmol) dissolved in toluene
(10 mL) was added. The reaction mixture was then left to attain
room temperature overnight. The mixture was diluted with CH2Cl2
and filtered through Celite. The filtrate was washed with 10% aq
Na2S2O3 and water, dried and concentrated. The crude product
was purified by column chromatography (99:1 CH2Cl2–acetone)
to yield 20 (1.2 g, 74%) as a colourless syrup. [a] +113 (c 0.16 in
D
CHCl3); 1H NMR (CDCl3): d 8.19–7.17 (m, 37H, aromatic), 5.87 (d,
1H, J 3 Hz, H-4), 5.83 (d, 1H, J 3 Hz, H-4I), 5.65 (t, 1H, J 10 Hz, H-
2), 5.55 (t, 1H, J 8 Hz, H-2I), 5.48 (dd, 1H, J 10 Hz, J 3 Hz, H-3),
4.86 (d, 1H, J 10 Hz, H-1), 4.85 (d, 1H, J 13 Hz, ArCHa), 4.65 (d,
1H, J 8 Hz, H-1I), 4.64 (d, 1H, J 13 Hz, ArCHb), 4.21–4.07 (m, 3H,
H-5, H-6I , H-6I ), 3.96 (dd, 1H, J 4 Hz, J 11 Hz, 1H, H-6a), 3.90–
3.20. 3-Azidopropyl 2,3,5-tri-O-benzoyl-
(1?3)-6-O-acetyl-2,4-di-O-benzoyl-b- -galactopyranosyl-
(1?6)-2,3,4-tri-O-benzoyl-b- -galactopyranosyl-(1?6)-[2,3,5-
tri-O-benzoyl- -arabinofuranosyl-(1?3)]-2,4-di-O-benzoyl-b-
-galactopyranosyl-(1?6)-2,3,4-tri-O-benzoyl-b-
galactopyranoside (23)
a-L-arabinofuranosyl-
D
D
a-L
D
D-
a
b
3.85 (m, 2H, H-5, H-6b), 3.81 (dd, 1H, J 3 Hz, J 10 Hz, H-3I), 1.98
(s, 3H, COCH3); 13C NMR (CDCl3): d 170.43, 165.86, 165.29,
165.13 and 165.06 (6 CO), 101.21 (C-1I), 85.31 (C-1), 77.06 (C-5),
76.06 (C-3I), 72.97 (C-5I), 71.36 (C-3), 70.92 (C-2I), 68.61 (C-4),
67.84 (C-2), 66.41 (C-4I), 70.97 (CH2), 67.70 (C-6I), 62.16 (C-6),
20.60 (COCH3). MALDI-TOFMS: calcd for C66H56O16S: 1136.33
[M]. Found: 1159.42 [M+Na]+; Anal. Calcd for C66H56O16S: C,
69.71; H, 4.96. Found: C, 69.98; H, 4.63.
A solution of donor 17 (500 mg, 0.35 mmol), acceptor 22
(400 mg, 0.29 mmol) and 4 Å molecular sieves in dry CH2Cl2
(5 mL) was cooled to ꢁ20 °C. After stirring for 30 min at ꢁ20 °C a
mixture of NIS (89 mg, 0.4 mmol) in dry THF (500
lL) and AgOTf
(13 mg, 0.05 mmol) in dry toluene (500
lL) was added dropwise.
Then the mixture was treated as described for the preparation of
13. The crude product was purified by silica column chromatogra-
phy (98:2 CH2Cl2–EtOAc) to yield 23 (570 mg, 75%) as a colourless
3.18. Phenyl 6-O-acetyl-2,4-di-O-benzoyl-b-
D
-galactopyranosyl-
syrup. [a]
+65.8 (c 0.11 in CHCl3); 1H NMR (CDCl3): d 8.16–7.09
D
(1?6)-2,3,4-tri-O-benzoyl-1-thio-b- -galactopyranoside (21)
D
(m, 80H, aromatic), 5.86–5.78 (m, 3H, H-4, H-4I, H-4III), 5.70 (d,
1H, J 3 Hz, H-4IV), 5.67–5.39 (m, 8H, H-2, H-2I, H-2III, H-2IV, H-3,
H-3II, H-3III, H-3V), 5.31 (s, 1H, H-2V), 5.28 (s, 1H, H-2II), 5.25 (d,
2H, J 1 Hz, H-1II, H-1V), 5.06–5.00 (m, 2H, H-4II, H-5IaI), 4.92 (dd,
1H, J 12 Hz, J 3 Hz, H-5aV), 4.83–4.71 (m, 2H, H-4V, H-5IbI), 4.66
(dd, 1H, J 12 Hz, J 4 Hz, H-5Vb ), 4.60 (d, 1H, J 8 Hz, H-1), 4.55 (d,
1H, J 8 Hz, H-1I), 4.54 (d, 1H, J 8 Hz, H-1III), 4.29 (d, 1H, J 8 Hz, H-
1IV), 4.17–3.98 (m, 3H, H-3, H-5, H-6a), 4.02 (dd, 1H, J 10 Hz, J
3 Hz, H-3IV), 3.94–3.77 (m, 6H, H-5III, H-5I, H-5IV, H-6aIV, H-6IbV,
To a solution of compound 20 (1 g, 0.88 mmol) in 4:1 CH2Cl2–
MeOH (50 mL) were added DDQ (318 mg, 1.4 mmol) and a trace
of H2O. Then the mixture was treated as described for the prepara-
tion of 13. The crude product was purified by silica column chro-
matography (3:2 hexane–EtOAc) to yield 21 (670 mg, 76%) as a
colourless syrup. [a]
+81.4 (c 0.14 in CHCl3); 1H NMR (CDCl3): d
D
8.25–7.13 (m, 30H, aromatic), 5.90 (d, 1H, J 3 Hz, 1H, H-4), 5.70
(t, 1H, J 10 Hz, H-2), 5.63 (d, 1H, J 3 Hz, H-4I), 5.51 (dd, 1H, J
H-6I ), 3.70 (dd, 1H, J 10 Hz, J 8 Hz, H-6b), 3.63–3.52 (m, 2H,
a

A. Fekete et al. / Carbohydrate Research 344 (2009) 1434–1441
1441
H-6III, CHa), 3.49–3.41 (m, 1H, H-6I ), 3.36–3.17 (m, 1H, CHb), 3.11–
ourless syrup. [
a
]
D ꢁ34.3 (c 0.10 in H2O); 1H NMR (D2O): d 5.24 (s,
a
b
3.03 (m, 1H, H-6III), 3.05 (t, 2H, J 7 Hz, CH2), 1.61–1.36 (m, 2H, CH2),
2H, H-2II, H-2V), 4.56, 4.52, 4.48 and 4.43 (4d, 4H, J 8 Hz, H-1, H-1I,
H-1III, H-1IV), 4.22 (s, 2H), 4.19–3.62 (m, 32H), 3.59–3.51 (m, 2H),
3.48 (t, 2H, J 7 Hz, CH2), 2.00–1.88 (m, 2H, CH2); 13C NMR (D2O):
d 109.23 (C-1II, C-1V), 103.38, 103.10, 103.02, 102.79 (C-1, C-1I, C-
1III, C-1IV), 83.82, 81.28, 80.26, 80.12, 76.52, 75.12, 74.95, 73.74,
73.39, 72.71, 72.56, 70.66, 69.88, 69.81, 68.62 and 68.46 (C-2, C-
2I, C-2II,C-2III, C-2IV, C-2V, C-3, C-3I, C-3II, C-3III, C-3IV, C-3V, C-4, C-
4I, C-4II, C-4III, C-4IV, C-4V, C-5, C-5I, C-5III, C-5IIII), 69.27, 69.14,
67.38, 61.21 and 60.96 (CH2, C-5II, C-5V, C-6, C-6I, C-6III, C-6IV),
b
1.88 (s, 3H, COCH3); 13C NMR (CDCl3): d 170.26, 166.15, 165.79,
165.63, 165.34, 164.95, 164.88 and 164.62 (17 CO), 107.73 (C-1II,
C-1V), 101.30 (C-1, C-1I), 100.95 (C-1III), 100.39 (C-1IV), 82.65 (C-
2V), 82.45 (C-2II), 81.61 (C-4II), 81.49 (C-4V), 77.50 (C-3II, C-3V),
76.02 (C-3I, C-3IV), 73.10, 72.36, 71.80, 71.60, 71.30, 69.99, 69.85,
69.46 and 68.72 (C-2, C-2I, C-2III, C-2IV, C-3, C-3III, C-4, C-4I, C-4IV,
C-5, C-5I, C-5III, C-5IV), 67.86 (C-4III), (C-6), 66.45 (C-6I), 66.17
(CH2), 65.68 (C-6III), 63.28 (C-5II, C-5V) 61.61 (C-6IV), 47.75 (CH2),
28.70 (CH2), 20.51 (COCH3). MALDI-TOFMS: calcd for
C151H129N3O46: 2719.78 [M]. Found: 2744.67 [M+Na]+; Anal. Calcd
for C151H129N3O46: C, 66.64; H, 4.78. Found: C, 66.27; H, 4.46.
47.89 (CH2), 28.25 (CH2). MALDI-TOFMS: calcd for C37H63N3O29
:
1013.35 [M]. Found: 1036.49 [M+Na]+.
3.24. 3-Aminopropyl
pyranosyl-(1?6)-b- -galactopyranosyl-(1?6)-[
-galactopyranosyl-(1?6)-b-D
a
-
L
-arabinofuranosyl-(1?3)-b-
-arabino-
-galacto-
D-galacto-
3.21. 3-Azidopropyl b-
D
-galactopyranosyl-(1?6)-[
a-L-arabino-
D
a-L
furanosyl-(1?3)]-b-
D-galactopyranosyl-(1?6)-b- -galacto-
D
furanosyl-(1?3)]-b-
D
pyranoside (24)
pyranoside (27)
To a solution of compound 18 (64 mg, 0.03 mmol) in CH2Cl2
(2 mL) were added MeOH (10 mL) and a catalytic amount of
NaOMe (pH ꢂ8). After stirring for 1 d at room temperature, the
mixture was neutralized with Amberlite IR-120 H+ ion-exchange
resin, filtered and concentrated. The residue was purified by
Sephadex LH20 chromatography to give 24 (19 mg, 81%) as a col-
A solution of compound 26 (30 mg, 0.029 mmol) in water
(15 mL) was treated as described for the preparation of 25 to give
27 (25 mg, 86%) as a white solid. [
a]
ꢁ28.3 (c 0.11 in H2O); 1H
D
NMR (D2O): d 5.22 (s, 2H, H-1II, H1V), 4.53, 4.50, 4.46 and 4.44
(4d, 4H, J 8 Hz, H-1, H-1I, H-1III, H-1IV), 4.20 (s, 2H, H-2II, H-2V),
4.16–3.59 (m, 32H), 3.57–3.47 (m, 2H), 3.09 (t, 2H, J 6.5 Hz, CH2),
2.02–1.91 (m, 2H, CH2); 13C NMR (D2O): d 109.19 (C-1II, C-1V),
103.37 103.08, 102.98 and 102.74 (C-1, C-1I, C-1III, C-1IV), 83.77,
81.25, 80.24, 80.09, 76.47, 74.92, 73.59, 73.39, 72.51, 70.61,
69.84, 69.77, 68.55 and 68.42 (C-2, C-2I, C-2II, C-2III, C-2IV, C-2V,
C-3, C-3I, C-3II, C-3III, C-3IV, C-3V, C-4, C-4I, C-4II, C-4III, C-4IV, C-4V,
C-5, C-5I, C-5III, C-5IV), 69.30, 67.97, 61.15 and 60.93 (CH2, C-5II,
C-5V, C-6, C-6I, C-6III, C-6IV), 37.50 (CH2), 27.45 (CH2). MALDI-
ourless syrup. [
a]
D
ꢁ21 (c 0.13 in H2O); 1H NMR (D2O): d 5.24 (s,
1H, H-1II), 4.55, 4.46 and 4.43 (3d, 3H, J 8 Hz, H-1, H-1I, H-1III),
4.22 (s, 1H), 4.19–4.11 (m, 2H), 4.10–3.61 (m, 20H), 3.59–3.51
(m, 2H), 3.48 (t, 2H, J 7 Hz, CH2), 1.99–1.87 (m, 2H, CH2); 13C
NMR (D2O): d 109.24 (C-1II), 103.34, 103.07, 102.78 (C-1, C-1I, C-
1III), 83.79, 81.27, 80.13, 76.50, 75.12, 73.80, 73.53, 72.67, 72.56,
70.67, 69.78, 68.63 and 68.42 (C-2, C-2I, C-2II,C-2III, C-3, C-3I, C-
3II, C-3III, C-4, C-4I, C-4II, C-4III, C-5, C-5I, C-5III), 69.16, 68.96,
67.36, 61.19 and 60.97 (CH2, C-5II, C-6, C-6I, C-6III), 47.87 (CH2),
28.24 (CH2). MALDI-TOFMS: calcd for C26H45N3O20: 719.26 [M].
Found: 742.30 [M+Na]+.
TOFMS: calcd for C37H65NO29
: 987.36 [M]. Found: 1010.68
[M+Na]+.
Acknowledgement
3.22. 3-Aminopropyl b-
D
-galactopyranosyl-(1?6)-[a-L-arabino-
furanosyl-(1?3)]-b-
ranoside (25)
D
-galactopyranosyl-(1?6)-b- -galactopy-
D
This work was supported by the Hungarian Scientific Research
Fund (PD73064 and NK48798).
To a solution of compound 18 (15 mg, 0.02 mmol) in H2O (5 mL)
was added 10% Pd/C. After stirring for 2 h under H2 at room tem-
perature, the mixture was filtered through Celite. The filtrate was
concentrated. The residue was lyophilized to give 25 (12 mg,
References
1. Knox, J. P. Int. J. Cytol. 1997, 171, 79–120.
82%) as a white solid. [
a]
ꢁ21.3 (c 0.09 in H2O); 1H NMR (D2O):
2. Anderson, M. A.; Sandrin, M. S.; Clarke, A. E. Plant Physiol. 1984, 75, 1013–1016.
3. Alban, S.; Classen, B.; Brunner, G.; Blaschek, W. Planta Med. 2002, 68, 1118–
1124.
4. Borbás, A.; Jánossy, L.; Lipták, A. Carbohydr. Res. 1999, 318, 98–109.
5. Csávás, M.; Borbás, A.; Jánossy, L.; Batta, Gy.; Lipták, A. Carbohydr. Res. 2001,
336, 107–115.
6. Csávás, M.; Borbás, A.; Szilágyi, L.; Lipták, A. Synlett 2002, 887–890.
7. Csávás, M.; Borbás, A.; Jánossy, L.; Lipták, A. Tetrahedron Lett. 2003, 44, 631–
635.
8. Classen, B.; Csávás, M.; Borbás, A.; Dingermann, T.; Zündorf, I. Planta Med. 2004,
70, 861–865.
9. Gu, G.; Yang, F.; Du, Y.; Kong, F. Carbohydr. Res. 2001, 336, 99–106.
10. Ning, J.; Wang, H.; Yi, Y. Tetrahedron Lett. 2002, 43, 7349–7352.
11. Li, A.; Kong, F. Carbohydr. Res. 2004, 339, 1847–1856.
12. Li, A.; Kong, F. Carbohydr. Res. 2005, 340, 1949–1962.
13. Li, A.; Kong, F. Bioorg. Med. Chem. 2005, 13, 839–853.
14. Sarkar, A. K.; Rostand, K. S.; Jain, R. K.; Matta, K. L.; Esko, J. D. J. Biol. Chem. 1997,
272, 25608–25616.
15. Gaunt, M. J.; Yu, J.; Spencer, J. B. J. Org. Chem. 1998, 63, 4172–4173.
16. Xia, J.; Abbas, S. A.; Piskorz, R. D.; Alderfel, J. L.; Matta, K. L. Tetrahedron Lett.
2000, 41, 169–173.
D
d 5.22 (s, 1H, H-1II), 4.54, 4.44 and 4.43 (3d, 3H, J 8 Hz, H-1, H-1I,
H-1III), 4.19 (s, 1H, H-2II), 4.16–3.59 (m, 24H), 3.57–3.47 (m, 2H,
H-2I, H-2III), 3.09 (t, 2H, J 7 Hz, CH2), 2.02–1.91 (m, 2H, CH2); 13C
NMR (D2O): d 109.30 (C-1II), 103.35 (C-1), 103.04, 102.73 (C-1I,
C-1III), 83.77 (C-2II), 81.25, 80.10, 76.46, 75.10, 73.63, 73.53,
72.65, 72.50, 70.66, 70.60, 69.74, 68.55 and 68.39 (C-2, C-2I, C-
2III, C-3, C-3I, C-3II, C-3III, C-4, C-4I, C-4II, C-4III, C-5, C-5I, C-5III),
69.32, 69.06, 67.96, 61.13 and 60.96 (CH2, C-5II, C-6, C-6I, C-6III),
37.50 (CH2), 27.43 (CH2). MALDI-TOFMS: calcd for C26H47NO20
:
693.27 [M]. Found: 716.31 [M+Na]+.
3.23. 3-Azidopropyl
a
-
L
-arabinofuranosyl-(1?3)-b-
-galactopyranosyl-(1?6)-[ -arabinofur-
-galactopyranosyl-(1?6)-b- -galactopy-
D-galacto-
pyranosyl-(1?6)-b-
D
a-L
anosyl-(1?3)]-b-
D
D
ranoside (26)
17. Choudhury (Mukherjee), J.; Minoura, N.; Uzawa, H. Carbohydr. Res. 2003, 338,
1265–1270.
To a solution of compound 23 (108 mg, 0.04 mmol) in CH2Cl2
(2 mL) was added MeOH (10 mL) and the mixture was treated as
described for the preparation of 24 to give 26 (35 mg, 86%) as a col-
18. Jain, R. K.; Matta, K. L. Carbohydr. Res. 1992, 226, 91–100.
19. Grindley, T. B. Adv. Carbohydr. Chem. Biochem. 1998, 53, 17–142.
20. Fletcher, H. G. Methods Carbohydr. Chem. 1963, 2, 228–230.