Synthesis of a mannose nonasaccharide existing in the exopolysaccharide of Cryphonectria parasitica

Article abstract of DOI:10.1016/S0008-6215(03)00267-2

α-D-Manp-(1→2)-α-D-Manp-(1→2)-α-D-Manp- (1→6)[α-D-Manp-(1→3)-α-D-Manp-(1→2)-α-D- Manp-(1→2)]-α-D-Manp-(1→6)-[α-D-Manp-(1→2)]- α-D-Manp, existing in the exopolysaccharide of Cryphonectria parasitica was synthesized as its allyl glycoside in a regio- and stereoselective manner.

Full text of DOI:10.1016/S0008-6215(03)00267-2

Carbohydrate Research 338 (2003) 1711ꢀ1718
/
www.elsevier.com/locate/carres
Synthesis of a mannose nonasaccharide existing in the
exopolysaccharide of Cryphonectria parasitica
Jianjun Zhang, Zuchao Ma, Fanzuo Kong*
Research Center for Eco-Environmental Sciences, Academia Sinica, P.O. Box 2871, Beijing 100085, PR China
Received 31 March 2003; accepted 4 June 2003
Abstract
a-
D
-Manp-(10
/
2)-a-D-Manp-(10
/
2)-a-
D
-Manp-(10
/
6)[a-
D
-Manp-(10
/
3)-a-
D
-Manp-(10
/
2)-a-
D
-Manp-(10
/
2)]-a-
D-Manp-
(10
/
6)-[a- -Manp-(10
D
/
2)]-a- -Manp, existing in the exopolysaccharide of Cryphonectria parasitica was synthesized as its allyl
D
glycoside in a regio- and stereoselective manner.
# 2003 Elsevier Ltd. All rights reserved.
Keywords: Oligosaccharide; Mannose; Synthesis
1. Introduction
Exopolysaccharides (EPSs) of fungi are thought to be
agents of phototoxicity and can play a role in plantꢀ
/
fungal interactions.1 Cryphonectria parasitica (Murr.)
Barr is the causal agent of chestnut blight,2 which is
characterized by the formation of a ‘gelatinous zone’
beyond the advancing edge of the mycelium. The
structure of a new EPS from the virulent strain of C.
parasitica was elucidated3 by means of 2D NMR
spectroscopy and mild hydrolysis and acetolysis. The
polysaccharide has a rather complex structure that can
be idealized as follows:
As an ongoing project for investigation of the
structureꢀ
we have reported the synthesis of a variety of biologi-
cally important oligosaccharides, such as (103)-
branched (10 6)-branched
6)-linked glucans,4 (10
(10 6)-linked
/
function relationships of oligosaccharides,
/
2. Results and discussion
/
/
/
3)-linked glucans,5 (10
/
2)-branched (10
/
mannans,6 3,6-branched mannans7 etc. Now we present
the synthesis of the mannose nonasaccharide existing in
the idealized structure of the EPSs of C. parasitica.
As outlined in Scheme 1, selective acetylation of allyl
4,6-O-benzylidene-a-
chloride in pyridine gave allyl 3-O-acetyl-4,6-O-benzyl-
idene-a- -mannopyranoside (2) in satisfactory yield
D-mannopyranoside (1) with acetyl
D
(91%), and no acetyl migration was observed. Mean-
while, selective glycosylation of 1 with perbenzoylated
mannosyl trichloroacetimidate afforded the (10
linked disaccharide 7 (76%). The regioselectivity was
1
confirmed by benzoylation of 7 to give 8, and the H
/
3)-
* Corresponding author. Tel.: ꢁ
10-62923563.
E-mail address: fzkong@mail.rcees.ac.cn (F. Kong).
/
86-10-62936613; fax: ꢁ86-
/
0008-6215/03/$ - see front matter # 2003 Elsevier Ltd. All rights reserved.
doi:10.1016/S0008-6215(03)00267-2

1712
J. Zhang et al. / Carbohydrate Research 338 (2003) 1711ꢀ1718
/
Scheme 1. (a) CH3COCl, CH2Cl2, pyridine; (b) ClCH2COCl, CH2Cl2, pyridine; (c) 90% TFA, 2 h, rt; (d) TMSOTf, CH2Cl2; (e)
BzClꢀpyridine (dry); (f) Ac2Oꢀpyridine (dry); (g) PdCl2, 90% HOAcꢀNaOAc, rt, 12 h; then Cl3CN, DBU, CH2Cl2 2ꢀ4 h; (h)
thiourea in EtOHꢀCH2Cl2; (i) satd NH3ꢀMeOH, rt, 72 h.
/
/
/
/
/
/
NMR spectrum of 8 showed two characteristic signals
for H-2 and H-2? at d 5.63 (J1,2 1.4, J2,3 3.2 Hz) and 5.76
(J1,2 0.9, J2,3 2.8 Hz) ppm, respectively. Debenzylidena-
tion of 8, followed by acetylation, furnished 10 (82% for
two steps). Subsequent deallylation and trichloroaceti-
midation yielded the disaccharide donor 11 (83% for
two steps). Condensation of 11 with allyl 3,4,6-tri-O-
benzoyl-a-D-mannopyranoside (12) gave a trisaccharide

J. Zhang et al. / Carbohydrate Research 338 (2003) 1711ꢀ
/1718
1713
13. Reiteration of the deallylation and trichloroacetimi-
dation transformed 13 to the trisaccharide donor 14,
which was used to build one side chain. For construc-
tion of the other side chain, 2 was chloroacetylated to
afford 3, and subsequent debenzylidenation furnished
the monosaccharide acceptor 4. Selective 6-O-glycosyla-
meters for solutions in CDCl3 or in D2O as indicated.
Chemical shifts are expressed in ppm downfield from the
Me4Si absorption. Mass spectra were recorded with a
VG PLATFORM mass spectrometer using the electro-
spray-ionization (ESI) mode. Thin-layer chromatogra-
phy (TLC) was performed on silica gel HF with
detection by charring with 30% (v/v) sulfuric acid in
MeOH or by UV detection. Column chromatography
tion8 of 4 with perbenzoylated (10
ide donor 157b gave (10
6)-linked tetrasaccharide 16
/
2)-linked trisacchar-
/
(88%). The selective 6-O-glycosylation was verified by
acetylation of 16 to furnish 17, and the 1H NMR
spectrum of 17 showed a newly emerged signal at d 5.45
was conducted by elution of a column (8ꢃ
240, 18ꢃ300, 35ꢃ400 mm) of silica gel (100ꢀ
mesh) with EtOAcꢀpetroleum ether (bp 60ꢀ90 8C) as
/
100, 16ꢃ
/
/
/
/
200
/
/
with J3,4
ꢂ
/
J4,5
ꢂ
/
9.9 Hz for H-4 compared to 16.
the eluent. Analytical LC was performed with a Gilson
HPLC consisting of a pump (model 306), stainless steel
Subsequent dechloroacetylation of 17 with thiourea
gave the tetrasaccharide acceptor 18 (84%). Condensa-
tion of 18 with 14 was carried out smoothly giving the
heptasaccharide 19 (68%). Deallylation of 19, followed
by trichloroacetimidation, afforded the heptasaccharide
donor 20 (78%). For completion of the assembly of the
nonasaccharide, another disaccharide unit was pre-
pared. Thus, coupling of 2 with perbenzoylated manno-
syl trichloroacetimidate furnished the disaccharide 5,
and subsequent debenzylidenation afforded the disac-
charide acceptor 6 (86%). The nonasaccharide 21 was
readily obtained by 6-O-selective glycosylation of the
disaccharide acceptor 6 with the heptasaccharide donor
20 (75%). Acetylation of 21 gave 22, whose 1H spectrum
showed one more signal, compared to 21, at d 5.32 ppm
column packed with silica gel (Spherisorb SiO2, 10ꢃ
or 4.6ꢃ250 mm), differential refractometer (132-RI
Detector), UV/vis detector (model 118). EtOAcꢀpetro-
leum ether (bp 60ꢀ90 8C) was used as the eluent at a
flow rate of 1ꢀ4 mL/min. Solutions were concentrated
at a temperature B60 8C under diminished pressure.
/
300
/
/
/
/
/
3.2. Allyl 3-O-acetyl-4,6-O-benzylidene-a-D-
mannopyranoside (2)
Compound 1 (3.08 g, 10 mmol) was dissolved in dry
CH2Cl2 (40 mL) containing Py (8.1 mL, 100 mmol),
then under N2 protection, acetyl chloride (0.8 mL, 11
mmol) in anhyd CH2Cl2 (10 mL) was added dropwise to
the solution within 30 min at 0 8C. The reaction mixture
was slowly raised to room temperature (rt) and stirred
for 2 h, at the end of which time TLC (3:1 petroleum
with J3,4
ꢂ
/
J4,5
tive 6-O-glycosylation. Deacylation of 22 was carried
ꢂ9.9 Hz for H-4, confirming the selec-
/
out in a saturated solution of ammonia in methanol
giving the target nonasaccharide 23, and the 1H and 13
C
etherꢀEtOAc) indicated that the reaction was complete.
/
NMR spectra of 23 showed characteristic signals such as
at d 5.16, 5.16, 5.14, 5.01, 4.99, 4.98, 4.96, 4.91, and 4.88
for 9 H-1s, and d 104.9, 104.8, 104.8, 104.7, 103.2, 103.2,
100.7, 100.6, 100.2 for 9 C-1s, and d 81.39, 81.38, 81.37,
81.02, 81.01, and 80.51 for glycosylated 5 C-2s and 1 C-
3. Since only six signals were found at d 80ꢀ
rest of the C-2 to C-6 signals were all at Bd 76, the 6-O-
glycosylation of 6 was again confirmed by this; other-
wise, if C-4 were glycosylated, a signal at d ꢀ80 would
have appeared.
The reaction mixture was diluted with CH2Cl2 (100 mL),
washed with water, 1 N HCl, and dried over Na2SO4.
The solution was concentrated, and purification of the
residue by column chromatography on a silica gel
column (3:1 petroleum etherꢀ
2 (3.17 g, 90.6%) as a syrup: [a]D
1H NMR (400 MHz, CDCl3): d 7.46ꢀ
PhH), 5.88 (m, 1 H, CH2ꢀCHCH2O), 5.55 (s, 1 H,
PhCHO2), 5.36 (dd, 1 H, J2,3 3.2 Hz, J3,4 10.0 Hz, H-3),
5.20 (m, 1 H, CH2ꢀCHCH2O), 5.23 (m, 1 H, CH2ꢀ
CHCH2O), 4.89 (d, 1 H, J1,2 1.5 Hz, H-1), 4.28 (dd, 1
H, J 4.8, 10.6 Hz, H-6a), 4.19 (m, 1 H, CH2ꢀCHCH2O),
4.15 (dd, 1 H, J1,2 1.5 Hz, J2,3 3.2 Hz, H-2), 4.09 (dd, 1
H, J 10.0, 10.6 Hz, H-6b), 4.02 (m, 1 H, CH2ꢀ
CHCH2O), 3.99 (ddd, 1 H, J 4.8, 10.0, 10.6 Hz, H-5),
3.84 (dd, 1 H, J3,4 J4,5 10.0 Hz, H-4), 2.12 (s, 3 H,
/
EtOAc) gave compound
58.78 (c 1.0, CHCl3);
7.34 (m, 5 H,
/82, and the
ꢄ
/
/
/
/
/
/
/
In summary, a complex branched mannose nonasac-
charide was synthesized in a regio- and stereoselective
way by a simple procedure. Large-scale preparations
should be possible with this method.
/
/
ꢂ
/
ꢂ
/
3. Experimental
CH3CO). Anal. Calcd for C18H22O7: C, 61.70; H, 6.33.
Found: C, 61.54; H, 6.24.
3.1. General methods
Melting points were determined with a ‘Mel-Temp’
apparatus. Optical rotations were determined with a
3.3. Allyl 3-O-acetyl-4,6-O-benzylidene-2-O-
chloroacetyl-a-D-mannopyranoside (3)
PerkinꢀElmer model 241-MC automatic polarimeter for
/
solutions in a 1-dm, jacketed cell. 1H, 13C, and 2D NMR
spectra were recorded with Varian XL-400 spectro-
Compound 2 (3.50 g, 10 mmol) was dissolved in dry
CH2Cl2 (40 mL) containing Py (8.1 mL, 100 mmol),

1714
J. Zhang et al. / Carbohydrate Research 338 (2003) 1711ꢀ1718
/
then under N2 protection, chloroacetyl chloride (0.9 mL,
11 mmol) in anhyd CH2Cl2 (10 mL) was added dropwise
to the solution within 30 min at 0 8C. The reaction
mixture was slowly raised to rt and stirred for 2 h, at the
quenched with Et3N (2 drops). The solvents were
evaporated in vacuo to give a residue that was purified
by silica gel column chromatography (2:1 petroleum
etherꢀ
syrup: [a]D
CDCl3): d 8.08ꢀ
J3,4 J4,5 10.0 Hz, H-4?), 5.97 (dd, 1 H, J2,3 3.3 Hz,
J3,4 10.0 Hz, H-3?), 5.84 (m, 1 H, CH2ꢀCHCH2O), 5.29
/
EtOAc) to give disaccharide 5 (7.53 g, 81.1%) as a
39.58 (c 1.0, CHCl3); 1H NMR (400 MHz,
7.29 (m, 25 H, PhH), 6.14 (dd, 1 H,
end of which time TLC (3:1 petroleum etherꢀ
/EtOAc)
ꢄ
/
indicated that the reaction was complete. The reaction
mixture was diluted with CH2Cl2 (100 mL), washed with
water, 1 N HCl, and dried over Na2SO4. The solution
was concentrated, and purification of the residue by
column chromatography on a silica gel column (3:1
/
ꢂ
/
ꢂ
/
/
(dd, 1 H, J1,2 1.5 Hz, J2,3 3.3 Hz, H-2?), 5.71 (s, 1 H,
PhCHO2), 5.42 (dd, 1 H, J2,3 3.0 Hz, J3,4 9.8 Hz, H-3),
petroleum etherꢀ
91.1%) as a syrup: [a]D ꢁ
(400 MHz, CDCl3): d 7.47ꢀ
1 H, CH2ꢀCHCH2O), 5.58 (s, 1 H, PhCHO2), 5.36 (dd,
1 H, J2,3 3.5 Hz, J3,4 9.8 Hz, H-3), 5.42 (dd, 1 H, J1,2 1.5
Hz, J2,3 3.5 Hz, H-2), 5.34 (m, 1 H, CH2ꢀCHCH2O),
5.27 (m, 1 H, CH2ꢀCHCH2O), 4.85 (d, 1 H, J1,2 1.5 Hz,
H-1), 4.30 (dd, 1 H, J 4.2, 10.5 Hz, H-6a), 4.23 (m, 1 H,
CH2ꢀCHCH2O), 4.18, 4.16 (ABq, 2 H, J 15.2 Hz,
ClCH2COO), 4.06ꢀ3.98 (m, 3 H), 3.84 (dd, 1 H, J3,4
J4,5 9.8 Hz, H-4), 2.03 (s, 3 H, CH3CO). Anal. Calcd
/
EtOAc) gave compound 3 (3.88 g,
29.88 (c 1.0, CHCl3); 1H NMR
7.35 (m, 5 H, PhH), 5.91 (m,
5.29 (m, 1 H, CH2ꢀ
/
CHCH2O), 5.21 (d, 1 H, J1,2 1.5 Hz,
/
H-1?), 5.19 (m, 1 H, CH2ꢀ
/CHCH2O), 5.01 (d, 1 H, J1,2
/
1.4 Hz, H-1), 2.17 (s, 3 H, CH3CO). Anal. Calcd for
C52H48O16: C, 67.23; H, 5.21. Found: C, 67.08; H, 5.50.
/
/
/
3.6. Allyl 2,3,4,6-tetra-O-benzoyl-a-
D-mannopyranosyl-
(102)-3-O-acetyl-a- -mannopyranoside (6)
/
D
/
/
ꢂ
/
Compound 5 (4.64 g, 5 mmol) was dissolved in 90%
TFA (50 mL), and the mixture was stirred for 2 h at rt,
ꢂ
/
for C20H23ClO8: C, 56.27; H, 5.43. Found: C, 56.50; H,
5.31.
at the end of which time TLC (2:1 petroleum etherꢀ
/
EtOAc) indicated that the reaction was complete. The
mixture was diluted with toluene (200 mL) and con-
centrated in vacuo directly. The residue was passed
through a short silica gel column with 2:1 petroleum
3.4. Allyl 3-O-acetyl-2-O-chloroacetyl-a-D-
mannopyranoside (4)
etherꢀ
foamy solid: [a]D
MHz, CDCl3): d 8.08ꢀ
H, J3,4 J4,5 9.8 Hz, H-4?), 5.91 (dd, 1 H, J2,3 3.2 Hz,
J3,4 9.8 Hz, H-3?), 5.85 (m, 1 H, CH2ꢀCHCH2O), 5.70
/
EtOAc as the eluent to give 6 (3.59 g, 85.5%) as a
55.08 (c 1.0, CHCl3); 1H NMR (400
7.28 (m, 20 H, PhH), 5.97 (dd, 1
ꢄ
/
Compound 3 (4.26 g, 10 mmol) was dissolved in 90%
TFA (50 mL), and the mixture was stirred for 2 h at rt,
/
ꢂ
/
ꢂ
/
at the end of which time TLC (2:1 petroleum etherꢀ
/
/
EtOAc) indicated that the reaction was complete. The
mixture was diluted with toluene (200 mL) and con-
centrated in vacuo directly. The residue was passed
through a short silica gel column with 1:1 petroleum
(dd, 1 H, J1,2 1.5 Hz, J2,3 3.2 Hz, H-2?), 5.22 (d, 1 H, J1,2
1.5 Hz, H-1?), 5.21 (dd, 1 H, J2,3 3.1 Hz, J3,4 9.8 Hz, H-
3), 5.17ꢀ
/
5.10 (m, 2 H, CH2ꢀ
/
CHCH2O), 5.03 (d, 1 H,
J1,2 1.6 Hz, H-1), 2.22 (s, 3 H, CH3CO). Anal. Calcd for
C45H44O16: C, 64.28; H, 5.27. Found: C, 64.44; H, 5.20.
etherꢀ
foamy solid: [a]D
MHz, CDCl3): d 5.87 (m, 1 H, CH2ꢀ
(m, 1 H, CH2ꢀCHCH2O), 5.29 (dd, 1 H, J1,2 1.2 Hz, J2,3
3.1 Hz, H-2), 5.24 (m, 1 H, CH2ꢀCHCH2O), 5.22 (dd, 1
H, J2,3 3.1 Hz, J3,4 9.8 Hz, H-3), 4.85 (d, 1 H, J1,2 1.2 Hz,
H-1), 4.20 (m, 1 H, CH2ꢀCHCH2O), 4.13, 4.12 (ABq, 2
H, J 15.2 Hz, ClCH2COO), 4.03ꢀ3.97 (m, 2 H), 3.89ꢀ
/
EtOAc as the eluent to give 4 (3.02 g, 89.1%) as a
93.58 (c 1.0, CHCl3); 1H NMR (400
CHCH2O), 5.30
ꢄ
/
/
/
3.7. Allyl 2,3,4,6-tetra-O-benzoyl-a-D-mannopyranosyl-
/
(103)-4,6-O-benzylidene-a- -mannopyranoside (7)
/
D
/
To a cooled solution (ꢄ
/
20 8C) of 1 (3.08 g, 10 mmol)
-mannopyranosyl
/
/
and
2,3,4,6-tetra-O-benzoyl-a-
D
3.87 (m, 2 H), 3.76 (m, 1 H), 2.07 (s, 3 H, CH3CO).
Anal. Calcd for C13H19ClO8: C, 46.09; H, 5.65. Found:
C, 46.30; H, 5.38.
trichlroacetimidate (8.14 g, 11 mmol) in anhyd CH2Cl2
(50 mL) was added TMSOTf (18 mL, 0.05 mmol). The
mixture was stirred at this temperature for 2 h and then
quenched with Et3N (2 drops). The solvents were
evaporated in vacuo to give a residue that was purified
by silica gel column chromatography (2:1 petroleum
3.5. Allyl 2,3,4,6-tetra-O-benzoyl-a-
(102)-3-O-acetyl-4,6-O-benzylidene-a-
oside (5)
D
-mannopyranosyl-
/
D-mannopyran-
etherꢀ
76.3%): [a]D
MHz, CDCl3): d 8.08ꢀ
H, J3,4 J4,5 10.0 Hz, H-4?), 5.98 (dd, 1 H, J2,3 3.3 Hz,
J3,4 10.0 Hz, H-3?), 5.88 (dd, 1 H, J1,2 0.6 Hz, J2,3 3.3 Hz,
H-2?), 5.82 (m, 1 H, CH2ꢀCHCH2O), 5.67 (s, 1 H,
PhCHO2), 5.62 (d, 1 H, J1,2 0.6 Hz, H-1?), 5.29 (m, 1 H,
/
EtOAc) to give disaccharide 7 as a syrup (6.76 g,
33.78 (c 1.0, CHCl3); 1H NMR (400
7.19 (m, 25 H, PhH), 6.08 (dd, 1
ꢄ
/
To a cooled solution (ꢄ
/
20 8C) of 2 (3.50 g, 10 mmol)
/
and 2,3,4,6-tetra-O-benzoyl-a-
D-mannopyranosyl tri-
ꢂ
/
ꢂ
/
chloroacetimidate (8.14 g, 11 mmol) in anhyd CH2Cl2
(50 mL) was added TMSOTf (18 mL, 0.1 mmol). The
mixture was stirred at this temperature for 2 h and then
/

J. Zhang et al. / Carbohydrate Research 338 (2003) 1711ꢀ
/1718
1715
CH2ꢀ
/
CHCH2O), 5.18 (m, 1 H, CH2ꢀ
/
CHCH2O), 4.92
(d, 1 H, J1,2 0.8 Hz, H-1). Anal. Calcd for C50H46O15: C,
CHCH2O), 5.06 (d, 1 H, J1,2 1.0 Hz, H-1), 2.25 (s, 3 H,
CH3CO), 2.17 (s, 3 H, CH3CO). Anal. Calcd for
C54H50O18: C, 65.71; H, 5.11. Found: C, 65.90; H, 5.00.
67.71; H, 5.23. Found: C, 67.49; H, 5.40.
3.10. 2,3,4,6-Tetra-O-benzoyl-a-
(103)-4,6-di-O-acetyl-2-O-benzoyl-a-
osyl trichloroacetimidate (11)
D
-mannopyranosyl-
3.8. Allyl 2,3,4,6-tetra-O-benzoyl-a-
(103)-2-O-benzoyl-4,6-O-benzylidene-a-
oside (8)
D
-mannopyranosyl-
/
D-mannopyran-
/
D-mannopyran-
To a solution of 10 (4.93 g, 5 mmol) in 90% HOAc (50
mL) containing AcONa (1.47 g, 15 mmol) was added
To a solution of 7 (4.43 g, 5.0 mmol) in Py (20 mL) was
added benzoyl chloride (1.2 mL, 10 mmol). The reaction
mixture was stirred at rt for 12 h and then quenched
with MeOH (2.0 mL). The solvents were evaporated and
coevaporated with toluene in vacuo to give a residue
that was purified by silica gel column chromatography
9
PdCl2 (270 mg, 2.5 mmol), and the mixture was stirred
for 12 h, at the end of which time TLC (3:1 petroleum
etherꢀEtOAc) indicated that the reaction was complete.
/
The mixture was diluted with CH2Cl2 (150 mL), washed
with water and satd aq NaHCO3. The organic layer was
concentrated, and the residue was passed through a
(2:1 petroleum etherꢀ
syrup (4.36 g, 88.1%): [a]D
NMR (400 MHz, CDCl3): d 8.10ꢀ
6.06 (dd, 1 H, J3,4 J4,5 9.9 Hz, H-4?), 5.85 (m, 1 H,
CH2ꢀCHCH2O), 5.76 (dd, 1 H, J1,2 0.9 Hz, J2,3 2.8 Hz,
/
EtOAc) to give disaccharide 8 as a
1
ꢄ63.38 (c 1.0, CHCl3); H
/
short silica gel column with 2:1 petroleum etherꢀ
as the eluent to give crude 2,3,4,6-tetra-O-benzoyl-a-
mannopyranosyl-(103)-4,6-di-O-acetyl-2-O-benzoyl-
a,b- -mannopyranose as a syrup. Dried under high
/EtOAc
/7.21 (m, 30 H, PhH),
D-
ꢂ
/
ꢂ
/
/
/
D
H-2), 5.73 (dd, 1 H, J2,3 3.2 Hz, J3,4 9.9 Hz, H-3?), 5.71
(s, 1 H, PhCHO2), 5.63 (d, 1 H, J1,2 1.4 Hz, J2,3 3.2 Hz,
H-2?), 5.48 (d, 1 H, J1,2 1.4 Hz, H-1?), 5.30 (m, 1 H,
vacuum for 2 h, the syrup was dissolved in CH2Cl2 (50
mL), and CCl3CN (2.5 mL, 25 mmol) and DBU (80 mL,
0.6 mmol) were added.10 The reaction mixture was
stirred for 12 h, at the end of which time TLC (3:1
CH2ꢀ
/
CHCH2O), 5.22 (m, 1 H, CH2ꢀ
/
CHCH2O), 5.04
(d, 1 H, J1,2 1.0 Hz, H-1). Anal. Calcd for C57H50O16: C,
petroleum etherꢀEtOAc) indicated that the reaction was
/
69.08; H, 5.09. Found: C, 68.94; H, 5.22.
complete. Concentration of the reaction mixture, fol-
lowed by purification of the crude product on a silica gel
column with 3:1 petroleum etherꢀ
furnished the disaccharide donor 11 (4.53 g, 83.1%) as a
foamy solid: [a]D
38.68 (c 1.0, CHCl3); 1H NMR (400
MHz, CDCl3): d 8.68 (s, 1 H, CNHCCl3), 8.26ꢀ7.25 (m,
25 H, PhH), 6.52 (d, 1 H, J1,2 1.0 Hz, H-1), 6.14 (dd, 1
H, J3,4 J4,5 10.1 Hz, H-4?), 5.77 (dd, 1 H, J1,2 1.8 Hz,
J2,3 3.2 Hz, H-2?), 5.74 (dd, 1 H, J3,4 J4,5 10.0 Hz, H-
4), 5.69 (dd, 1 H, J2,3 3.2 Hz, J3,4 10.1 Hz, H-3?), 5.53 (d,
1 H, J1,2 1.0 Hz, J2,3 3.1 Hz, H-2), 5.37 (d, 1 H, J1,2 1.8
Hz, H-1?), 2.29 (s, 3 H, CH3CO), 2.14 (s, 3 H, CH3CO).
Anal. Calcd for C53H46Cl3NO18: C, 58.33; H, 4.25.
Found: C, 58.54; H, 4.22.
/
EtOAc as the eluent,
3.9. Allyl 2,3,4,6-tetra-O-benzoyl-a-
(103)-4,6-di-O-acetyl-2-O-benzoyl-a-
oside (10)
D
-mannopyranosyl-
/
D-mannopyran-
ꢄ
/
/
Compound 8 (4.45 g, 5 mmol) was dissolved in 90%
TFA (50 mL), and the mixture was stirred for 2 h at rt,
at the end of which time TLC (2:1 petroleum etherꢀ
EtOAc) indicated that the reaction was complete. The
mixture was diluted with toluene (200 mL) and con-
centrated in vacuo directly. The residue was passed
through a short silica gel column with 2:1 petroleum
ꢂ
/
ꢂ
/
ꢂ
/
ꢂ
/
/
etherꢀEtOAc as the eluent to give 9 as a foamy solid.
/
Compound 9 was dissolved in Py (50 mL), then Ac2O
(20 mL, 20 mmol) was added. The reaction mixture was
stirred at rt for 12 h, at the end of which time TLC (4:1
3.11. Allyl 2,3,4,6-tetra-O-benzoyl-a-
(103)-4,6-di-O-acetyl-2-O-benzoyl-a-
osyl-(102)-3,4,6-tri-O-benzoyl-a- -mannopyranoside
(13)
D
-mannopyranosyl-
/
D-mannopyran-
petroleum etherꢀ
/
EtOAc) indicated that the reaction was
complete. The reaction mixture was concentrated, and
/
D
then the residue was purified by flash column chroma-
tography on a silica gel column (2:1 petroleum etherꢀ
/
To a cooled solution (ꢄ20 8C) of 12 (1.60 g, 3 mmol)
/
EtOAc) to give compound 10 (4.06 g, 82.4% for two
and 11 (3.60 g, 3.3 mmol) in anhyd CH2Cl2 (50 mL) was
added TMSOTf (18 mL, 0.05 mmol). The mixture was
stirred at this temperature for 2 h, and then quenched
with Et3N (2 drops). The solvents were evaporated in
vacuo to give a residue, which was purified by silica gel
1
steps) as a foamy solid: [a]D
NMR (400 MHz, CDCl3): d 8.06ꢀ
6.07 (dd, 1 H, J3,4 J4,5 9.8 Hz, H-4?), 5.84 (m, 1 H,
CH2ꢀCHCH2O), 5.68 (dd, 1 H, J2,3 3.0 Hz, J3,4 9.8 Hz,
H-3?), 5.61 (dd, 1 H, J3,4 J4,5 9.9 Hz, H-4), 5.58 (d, 1
ꢄ
/
51.68 (c 1.0, CHCl3); H
/7.22 (m, 25 H, PhH),
ꢂ
/
ꢂ
/
/
ꢂ
/
ꢂ
/
column chromatography (2:1 petroleum etherꢀ
to give trisaccharide 13 as a syrup (3.25 g, 74.2%): [a]D
40.58 (c 1.0, CHCl3); 1H NMR (400 MHz, CDCl3): d
8.14ꢀ7.24 (m, 40 H, PhH), 6.17 (dd, 1 H, J3,4 J4,5
/
EtOAc)
H, J1,2 0.6 Hz, J2,3 3.0 Hz, H-2?), 5.48 (d, 1 H, J1,2 1.0
Hz, J2,3 3.1 Hz, H-2), 5.31 (d, 1 H, J1,2 0.6 Hz, H-1?),
ꢄ
/
5.27 (m, 1 H, CH2ꢀ
/
CHCH2O), 5.18 (m, 1 H, CH2ꢀ
/
/
ꢂ
/
ꢂ
/

1716
J. Zhang et al. / Carbohydrate Research 338 (2003) 1711ꢀ1718
/
10.4 Hz, H-4), 5.96 (m, 1 H, CH2ꢀ
/
CHCH2O), 5.95 (dd,
H-2), 5.32ꢀ
/
5.22 (m, 2 H, CH2ꢀ
/
CHCH2O), 5.28 (d, 1 H,
1 H, J3,4 J4,5 9.9 Hz, H-4), 5.83 (dd, 1 H, J2,3 3.2 Hz,
ꢂ
/
ꢂ
/
J1,2 1.0 Hz, H-1), 4.99 (d, 1 H, J1,2 0.8 Hz, H-1), 4.93 (d,
1 H, J1,2 0.5 Hz, H-1), 4.11, 4.09 (ABq, 2 H, J 15.3 Hz,
ClCH2COO), 2.03 (s, 3 H, CH3CO); 13C NMR (100
MHz, CDCl3): d 171.0 (CH3CO), 166.9, 166.6, 166.5,
165.9, 165.8, 165.6, 165.5, 165.4, 165.4, 165.1, 164.9 (11
C, 10 PhCO, ClCH2CO), 118.4 (CH2ꢀ
100.6, 99.7, 98.4, 96.5 (4 C, 4 C-1), 72.3, 72.1, 71.4,
71.1, 70.6, 70.2, 69.8, 69.7, 69.6, 68.7, 68.7, 68.0, 67.5,
J3,4 10.0 Hz, H-3), 5.73 (d, 1 H, J1,2 1.6 Hz, J2,3 3.2 Hz,
H-2), 5.68 (dd, 1 H, J2,3 3.2 Hz, J3,4 9.9 Hz, H-3), 5.61
(dd, 1 H, J3,4
Hz, J2,3 2.9 Hz, H-2), 5.37 (d, 1 H, J1,2 1.6 Hz, H-1), 5.33
(m, 1 H, CH2ꢀCHCH2O), 5.26 (m, 1 H, CH2ꢀ
ꢂ
/
J4,5
ꢂ9.9 Hz, H-4), 5.58 (d, 1 H, J1,2 1.7
/
/
/
/CHCH2O),
CHCH2O), 5.22 (d, 1 H, J1,2 1.6 Hz, H-1), 5.17 (d, 1
H, J1,2 1.4 Hz, H-1), 2.21 (s, 3 H, CH3CO), 2.13 (s, 3 H,
CH3CO); 13C NMR (100 MHz, CDCl3): d 170.6, 170.2
(2 C, 2 CH3CO), 166.2, 166.0, 165.8, 165.5, 165.5, 165.4,
165.2, 165.1 (8 C, 8 PhCO), 118.4 (CH2ꢀ
99.6, 99.3, 97.8 (3 C, 3 C-1), 77.6, 76.3, 71.4, 71.0, 70.4,
69.9, 69.8, 69.7, 69.1, 68.9, 67.5, 67.2, 66.1, 63.6, 62.7,
66.7, 65.6, 65.6, 65.5, 64.0, 63.7, 62.8, 60.5 (21 C, C-2ꢀ
/6,
CH2ꢀCHCH2O), 29.6 (ClCH2CO), 20.9 (CH3CO).
/
/
CHCH2O),
Anal. Calcd for C101H89ClO33: C, 65.00; H, 4.81.
Found: C, 65.14; H, 5.03.
62.1 (16 C, C-2ꢀ
CH3CO). Anal. Calcd for C81H72O26: C, 66.57; H, 4.97.
Found: C, 66.74; H, 5.20.
/
6, CH2ꢀ
/
CHCH2O), 20.8, 20.8 (2 C, 2
3.14. Allyl 2,3,4,6-tetra-O-benzoyl-a-
(102)-3,4,6-tri-O-benzoyl-a- -mannopyranosyl-(10
3,4,6-tri-O-benzoyl-a- -mannopyranosyl-(106)-3,4-di-
O-acetyl-2-O-chloroacetyl-a- -mannopyranoside (17)
D
-mannopyranosyl-
/
D
/2)-
D
/
D
3.12. 2,3,4,6-Tetra-O-benzoyl-a-
(103)-4,6-di-O-acetyl-2-O-benzoyl-a-
osyl-(102)-3,4,6-tri-O-benzoyl-a- -mannopyranosyl
trichloroacetimidate (14)
D
-mannopyranosyl-
/
D-mannopyran-
To a solution of 16 (1.85 g, 1 mmol) in Py (20 mL) was
added Ac2O (10 mL, 10 mmol). The reaction mixture
was stirred at rt for 12 h, at the end of which time TLC
/
D
(2:1 petroleum etherꢀEtOAc) indicated that the reaction
/
Compound 13 (1.16 g, 0.8 mmol) was deallylated and
subsequently trichloroacetimidated under the same
conditions as those that were used for the preparation
of 11 from 9, giving 14 (1.07 g, 85.6%) as a foamy solid:
was complete. The reaction mixture was concentrated,
and then the residue was purified by flash column
chromatography on a silica gel column (2:1 petroleum
etherꢀ
foamy solid: [a]D
MHz, CDCl3): d 8.02ꢀ
H, J3,4 J4,5 9.9 Hz, H-4), 6.02 (dd, 1 H, J3,4
9.8 Hz, H-4), 6.01 (dd, 1 H, J3,4 J4,5 9.8 Hz, H-4),
5.95ꢀ5.88 (m, 3 H), 5.76ꢀ5.73 (m, 2 H), 5.45 (dd, 1 H,
J3,4 J4,5 9.9 Hz, H-4), 5.44ꢀ5.35 (m, 2 H), 5.44 (d, 1
H, J1,2 0.5 Hz, H-1), 5.40 (d, 1 H, J1,2 1.2 Hz, H-1), 5.26
(m, 1 H, CH2ꢀCHCH2O), 5.19 (d, 1 H, J1,2 1.4 Hz, H-
/
EtOAc) to give compound 17 (1.81 g, 94.8%) as a
1
[a]D
CDCl3): d 8.66 (s, 1 H, CNHCCl3), 8.14ꢀ
H, PhH), 6.60 (d, 1 H, J1,2 1.0 Hz, H-1), 6.17 (dd, 1 H,
J3,4 J4,5 10.0 Hz, H-4), 6.08 (dd, 1 H, J3,4 J4,5
ꢄ
/
30.58 (c 1.0, CHCl3); 1H NMR (400 MHz,
7.25 (m, 40
ꢄ
/
8.18 (c 1.0, CHCl3); H NMR (400
7.11 (m, 50 H, PhH), 6.08 (dd, 1
J4,5
/
/
ꢂ
/
ꢂ
/
ꢂ
/
ꢂ
/
ꢂ
/
ꢂ
/
ꢂ
/
ꢂ
/
ꢂ
/
ꢂ
/
9.9 Hz, H-4), 5.85 (dd, 1 H, J2,3 3.2 Hz, J3,4 10.0 Hz, H-
/
/
3), 5.72 (d, 1 H, J1,2 1.5 Hz, J2,3 3.3 Hz, H-2), 5.68 (dd, 1
H, J2,3 3.3 Hz, J3,4 9.9 Hz, H-3), 5.62 (dd, 1 H, J3,4
ꢂ
/
ꢂ
/
/
ꢂ
/
J4,5 9.8 Hz, H-4), 5.59 (d, 1 H, J1,2 1.6 Hz, J2,3 3.0 Hz,
ꢂ
/
/
H-2), 5.35 (d, 1 H, J1,2 1.6 Hz, H-1), 5.30 (d, 1 H, J1,2 1.5
Hz, H-1), 2.20 (s, 3 H, CH3CO), 2.11 (s, 3 H, CH3CO).
Anal. Calcd for C80H68Cl3NO26: C, 61.37; H, 4.38.
Found: C, 61.50; H, 4.22.
1), 4.95 (d, 1 H, J1,2 1.0 Hz, H-1), 4.16, 4.07 (ABq, 2 H,
J 15.1 Hz, ClCH2COO), 2.04 (s, 3 H, CH3CO), 2.02 (s, 3
H, CH3CO); 13C NMR (100 MHz, CDCl3): d 170.0,
169.7 (2 C, 2 CH3CO), 167.0, 166.4, 166.4, 165.9, 165.7,
165.7, 165.5, 165.4, 165.4, 165.1, 164.9 (11 C, 10 PhCO,
ClCH2CO), 118.7 (CH2ꢀ
/
CHCH2O), 100.7, 99.7, 98.6,
3.13. Allyl 2,3,4,6-tetra-O-benzoyl-a-
(102)-3,4,6-tri-O-benzoyl-a- -mannopyranosyl-(10
3,4,6-tri-O-benzoyl-a- -mannopyranosyl-(106)-3-O-
acetyl-2-O-chloroacetyl-a- -mannopyranoside (16)
D
-mannopyranosyl-
96.2 (4 C, 4 C-1), 71.5, 71.4, 70.5, 70.2, 69.9, 69.7, 69.6,
69.6, 69.4, 69.0, 68.8, 68.8, 67.6, 67.2, 66.6, 66.2, 66.0,
/
D
/
2)-
D
/
63.8, 63.8, 63.7, 62.8 (21 C, C-2ꢀ
29.7 (ClCH2CO), 20.9, 20.8 (CH3CO). Anal. Calcd for
103H91ClO34: C, 64.83; H, 4.81. Found: C, 64.90; H,
/
6, CH2ꢀ/CHCH2O),
D
C
5.02.
Compound 4 (676 mg, 2.0 mmol) and 15 (3.38 g, 2.0
mmol) were coupled under the same conditions as those
that were used for the preparation of 13 from 11 and 12,
giving 16 as a foamy solid (3.30 g, 88.5%): [a]D
ꢄ
/
26.58
(c 1.0, CHCl3); H NMR (400 MHz, CDCl3): d 8.06ꢀ
7.15 (m, 50 H, PhH), 6.05 (dd, 1 H, J3,4 J4,5 9.7 Hz,
H-4), 5.97 (dd, 1 H, J3,4 J4,5 9.8 Hz, H-4), 5.97ꢀ5.90
3.15. Allyl 2,3,4,6-tetra-O-benzoyl-a-
D
-mannopyranosyl-
2)-
6)-3,4-di-
1
/
(10
3,4,6-tri-O-benzoyl-a-
O-acetyl-a- -mannopyranoside (18)
/
2)-3,4,6-tri-O-benzoyl-a-
D
-mannopyranosyl-(10
/
ꢂ
/
ꢂ
/
D-mannopyranosyl-(10
/
ꢂ
/
ꢂ
/
/
D
(m, 4 H), 5.78 (dd, 1 H, J2,3 2.8 Hz, J3,4 9.7 Hz, H-3),
5.77 (d, 1 H, J1,2 0.8 Hz, J2,3 3.1 Hz, H-2), 5.41 (d, 1 H,
J1,2 0.8 Hz, H-1), 5.77 (d, 1 H, J2,3 1.0 Hz, J2,3 2.9 Hz,
To a solution of 17 (1.80 g, 0.94 mmol) in EtOH (25
mL)ꢀCH2Cl2 (100 mL) was added thiourea (0.36 g), and
/

J. Zhang et al. / Carbohydrate Research 338 (2003) 1711ꢀ
/1718
1717
the mixture was refluxed for 16 h, at the end of which
time TLC (3:1 petroleum etherꢀEtOAc) indicated that
the reaction was complete. The mixture was concen-
C179H156O58: C, 66.45; H, 4.86. Found: C, 66.64; H,
5.05.
/
trated. The residue was passed through a silica gel
3.17. 2,3,4,6-Tetra-O-benzoyl-a-
(102)-3,4,6-tri-O-benzoyl-a- -mannopyranosyl-(10
3,4,6-tri-O-benzoyl-a- -mannopyranosyl-(106)-[2,3,4,6-
tetra-O-benzoyl-a- -mannopyranosyl-(103)-4,6-di-O-
acetyl-2-O-benzoyl-a- -mannopyranosyl-(102)-3,4,6-
tri-O-benzoyl-a- -mannopyranosyl-(102)]-3,4-di-O-
acetyl-a- -mannopyranosyl trichloroacetimidate (20)
D-mannopyranosyl-
column with 3:1 petroleum etherꢀ
/
EtOAc as the eluent
16.58
(c 1.0, CHCl3); H NMR (400 MHz, CDCl3): d 8.09ꢀ
7.11 (m, 50 H, PhH), 6.06 (dd, 1 H, J3,4 J4,5 9.8 Hz,
H-4), 6.02 (dd, 1 H, J3,4 J4,5 9.9 Hz, H-4), 5.97ꢀ5.85
(m, 4 H), 5.76ꢀ5.73 (m, 2 H), 5.49 (dd, 1 H, J3,4 J4,5
9.9 Hz, H-4), 5.42 (d, 1 H, J1,2 0.6 Hz, H-1), 5.35ꢀ5.30
(m, 2 H), 5.28 (d, 1 H, J1,2 1.5 Hz, H-1), 5.19 (m, 1 H,
CH2ꢀCHCH2O), 4.93 (d, 1 H, J1,2 1.4 Hz, H-1), 4.91 (d,
/
D
/2)-
to give 18 (1.44 g, 83.7%) as a foamy solid: [a]D
ꢄ
/
D
/
1
/
D
/
ꢂ
/
ꢂ
/
D
/
ꢂ
/
ꢂ
/
/
D
/
/
ꢂ
/
ꢂ
/
D
/
Compound 19 (1.50 g, 0.46 mmol) was deallylated and
subsequently trichloroacetimidated under the same
conditions as those used for the preparation of 11
from 10, giving 20 (1.21 g, 78.1%) as a foamy solid:
/
1 H, H-1), 2.09 (s, 3 H, CH3CO), 2.04 (s, 3 H, CH3CO);
13C NMR (100 MHz, CDCl3): d 170.2, 169.8 (2 C, 2
CH3CO), 166.6, 166.5, 166.1, 165.7, 165.6, 165.5, 165.4,
[a]D
ꢄ
36.38 (c 1.0, CHCl3); 1H NMR (400 MHz,
CDCl3), (some characteristic signals are given): d 8.68
/
165.4, 165.1, 164.8 (10 C, 10 PhCO), 118.1 (CH2ꢀ
/
CHCH2O), 100.2, 99.7, 98.9, 98.7 (4 C, 4 C-1), 72.0,
71.2, 70.6, 70.2, 70.0, 69.9, 69.7, 69.5, 69.4, 68.9, 68.5,
68.5, 67.6, 67.5, 66.6, 66.5, 66.2, 63.9, 63.8, 62.8, 60.5 (21
(s, 1 H, CNHCCL3), 6.47 (d, 1 H, J1,2 1.8 Hz, H-1), 6.18
(dd, 1 H, J3,4
ꢂ/J4,5
ꢂ9.9 Hz, H-4), 5.73 (d, 1 H, J1,2 0.7
/
Hz, H-1), 5.47 (d, 1 H, J1,2 1.0 Hz, H-1), 5.36 (d, 2 H,
J1,2 1.0 Hz, 2 H-1), 5.14 (d, 1 H, J1,2 0.7 Hz, H-1), 4.91
(d, 1 H, J1,2 0.8 Hz, H-1), 2.17 (s, 3 H, CH3CO), 2.16 (s,
3 H, CH3CO), 2.10 (s, 3 H, CH3CO), 2.01 (s, 3 H,
CH3CO). Anal. Calcd for C178H152Cl3NO58: C, 64.02;
H, 4.59. Found: C, 64.30; H, 4.40.
C, C-2ꢀ
/
6, CH2ꢀ
/
CHCH2O), 21.1, 20.9 (CH3CO). Anal.
Calcd for C101H90O33: C, 66.22; H, 4.95. Found: C,
65.94; H, 4.83.
3.16. Allyl 2,3,4,6-tetra-O-benzoyl-a-
(102)-3,4,6-tri-O-benzoyl-a- -mannopyranosyl-(10
3,4,6-tri-O-benzoyl-a- -mannopyranosyl-(106)-[2,3,4,6-
tetra-O-benzoyl-a- -mannopyranosyl-(103)-4,6-di-O-
acetyl-2-O-benzoyl-a- -mannopyranosyl-(102)-3,4,6-
tri-O-benzoyl-a- -mannopyranosyl-(102)]-3,4-di-O-
acetyl-a- -mannopyranoside (19)
D
-mannopyranosyl-
/
D
/
2)-
3.18. Allyl 2,3,4,6-tetra-O-benzoyl-a-
(102)-3,4,6-tri-O-benzoyl-a- -mannopyranosyl-(10
3,4,6-tri-O-benzoyl-a- -mannopyranosyl-(106)-[2,3,4,6-
tetra-O-benzoyl-a- -mannopyranosyl-(103)-4,6-di-O-
acetyl-2-O-benzoyl-a- -mannopyranosyl-(102)-3,4,6-
tri-O-benzoyl-a- -mannopyranosyl-(102)]-3,4-di-O-
acetyl-a- 6)-[2,3,4,6-tetra-O-
-mannopyranosyl-(10
benzoyl-a- 2)]-3-O-acetyl-a-
-mannopyranosyl-(10
mannopyranoside (21)
D
-mannopyranosyl-
D
/
/
D
/2)-
D
/
D
/
D
/
D
/
D
/
D
/
D
D
/
D
/
Compound 14 (1.31 g, 0.84 mmol) and 18 (1.40 g, 0.76
mmol) were coupled under the same conditions as that
used for the preparation of 13 from 11 and 12, giving 19
D
/
D-
(1.66 g, 67.5%) as a foamy solid: [a]D
CHCl3); 1H NMR (400 MHz, CDCl3), (some character-
istic signals are given): d 6.14 (dd, 1 H, J3,4 J4,5 9.8
Hz, H-4), 6.03 (dd, 1 H, J3,4 J4,5 9.8 Hz, H-4), 5.96
(m, 1 H, OCH2CH ꢀCH2), 5.72 (dd, 1 H, J1,2 1.0 Hz,
J2,3 3.1 Hz, H-2), 5.68 (dd, 1 H, J2,3 3.1 Hz, J3,4
9.7 Hz, H-3), 5.59 (dd, 1 H, J3,4 J4,5 9.9 Hz, H-4),
5.55 (dd, 1 H, J1,2 1.4 Hz, J2,3 3.2 Hz, H-2), 5.48 (d,
ꢄ
/
31.58 (c 1.0,
To a cooled solution (ꢄ20 8C) of 20 (1.00 g, 0.3 mmol)
/
and 6 (0.50 g, 0.6 mmol) in anhyd CH2Cl2 (50 mL)
was added TMSOTf (9 mL, 0.05 mmol). The mixture
was stirred at this temperature for 2 h and then
quenched with Et3N (2 drops). The solvents were
evaporated in vacuo to give a residue that was purified
by silica gel column chromatography (2:1 petroleum
ꢂ
/
ꢂ
/
ꢂ
/
ꢂ
/
/
ꢂ
/
ꢂ
/
ꢂ
/
ꢂ
/
ꢂ
/
ꢂ
/
ꢂ
/
ꢂ
/
etherꢀ
74.8%) as a syrup: [a]D
NMR (400 MHz, CDCl3, some characteristic signals
are given): d 6.17 (dd, 1 H, J3,4 J4,5 9.9 Hz, H-4),
6.13 (dd, 1 H, J3,4 J4,5 9.8 Hz, H-4), 6.08 (dd, 1 H,
J3,4 J4,5 9.7 Hz, H-4), 5.57 (d, 1 H, J1,2 1.0 Hz,
/
EtOAc) to give nonasaccharide 21 (898 mg,
1 H, J1,2 0.7 Hz, H-1), 5.46 (d, 1 H, J1,2 0.6 Hz, H-1),
5.37 (d, 1 H, J1,2 1.9 Hz, H-1), 5.33 (d, 1 H, J1,2 1.9 Hz,
ꢄ
/
33.08 (c 1.0, CHCl3); 1H
H-1), 5.23 (m, 1 H, CH2ꢀ/CHCH2O), 5.15 (d, 1 H, J1,2
ꢂ
/
ꢂ
/
0.7 Hz, H-1), 5.06 (s, 1 H, J1,2 1.7 Hz, H-1), 4.92 (d, 1 H,
J1,2 1.5 Hz, H-1), 2.19 (s, 3 H, CH3CO), 2.12 (s, 3 H,
CH3CO), 2.09 (s, 3 H, CH3CO), 2.01 (s, 3 H, CH3CO);
13C NMR (100 MHz, CDCl3): d 170.6, 170.3, 170.2,
169.7 (4 C, 4 CH3CO), 166.4, 166.3, 166.2, 165.9, 165.8,
165.7, 165.6, 165.5, 165.4, 164.8 (18 C, 18 PhCO, some
ꢂ
/
ꢂ
/
ꢂ
/
ꢂ
/
H-1), 5.48 (d, 1 H, J1,2 1.5 Hz, H-1), 5.36 (d, 1 H, J1,2 1.1
Hz, H-1), 5.32 (d, 1 H, J1,2 0.9 Hz, H-1), 5.29 (d, 1 H,
J1,2 0.7 Hz, H-1), 5.24 (d, 1 H, J1,2 0.6 Hz, H-1), 5.18 (d,
1 H, J1,2 1.0 Hz, H-1), 5.03 (d, 1 H, J1,2 0.8
Hz, H-1), 4.99 (d, 1 H, J1,2 1.2 Hz, H-1), 2.16 (s, 3 H,
CH3CO), 2.09 (s, 3 H, CH3CO), 2.07 (s, 3 H, CH3CO),
1.99 (s, 3 H, CH3CO), 1.81 (s, 3 H, CH3CO); 13C NMR
signals overlapped), 118.2 (CH2ꢀ
/
CHCH2O), 100.3,
100.0, 99.7, 99.4, 99.2, 98.7, 97.9 (7 C, 7 C-1), 21.1,
20.9, 20.9, 20.8 (4 C, 4 CH3CO). Anal. Calcd for

1718
J. Zhang et al. / Carbohydrate Research 338 (2003) 1711ꢀ1718
/
(100 MHz, CDCl3): d 171.6, 170.6, 170.1, 169.9, 169.8 (5
C, 5 CH3CO), 166.9ꢀ164.9 (PhCO, some signals
CHCH2O), 100.2, 100.0, 99.8,
99.6, 99.3, 99.1, 98.6, 98.1, 97.7 (9 C, 9 C-1), 22.8, 21.1,
21.0, 20.8, 20.6 (5 C, CH3CO). Anal. Calcd for
some characteristic signals are given): d 5.83 (m, 1 H,
OCH2CH ꢀCH2), 5.22 (m, 1 H, OCH2CHꢀCH2), 5.16
/
/
/
overlapped), 118.0 (CH2ꢀ
/
(s, 1 H, H-1), 5.16 (s, 1 H, H-1), 5.14 (s, 1 H, H-1), 5.01
(d, 1 H, J1,2 1.2 Hz, H-1), 4.99 (d, 1 H, J1,2 1.2 Hz, H-1),
4.98 (s, 1 H, H-1), 4.96 (s, 1 H, H-1), 4.91 (s, 1 H, H-1),
C221H194O73: C, 66.06; H, 4.86. Found: C, 65.94; H,
5.01.
4.89 (m, 1 H, OCH2CHꢀ
/
CH2), 4.88 (s, 1 H, H-1); 13C
CHCH2O),
NMR (100 MHz, D2O): d 121.2 (CH2ꢀ
/
104.9, 104.8, 104.8, 104.7, 103.2, 103.2, 100.7, 100.6,
100.2 (9 C, 9 C-1), 81.39, 81.38, 81.37, 81.02, 81.01,
80.51. MALDI-TOF MS Calcd for C57H96O46: 1517.34
3.19. Allyl 2,3,4,6-tetra-O-benzoyl-a-
D
-mannopyranosyl-
2)-
6)-[2,3,4,6-
3)-4,6-di-O-
-mannopyranosyl-(102)-3,4,6-
-mannopyranosyl-(102)]-3,4-di-O-
-mannopyranosyl-(106)-[2,3,4,6-tetra-O-
benzoyl-a- 2)]-3,4-di-O-acetyl-a-
-mannopyranosyl-(10
-mannopyranoside (22)
(10
3,4,6-tri-O-benzoyl-a-
tetra-O-benzoyl-a- -mannopyranosyl-(10
acetyl-2-O-benzoyl-a-
tri-O-benzoyl-a-
acetyl-a-
/
2)-3,4,6-tri-O-benzoyl-a-
D
-mannopyranosyl-(10
/
D-mannopyranosyl-(10
/
[M]. Found: 1540.41 [MꢁNa].
/
D
/
D
/
D
/
Acknowledgements
D
/
D
/
This work was supported by The Chinese Academy of
Sciences (KZCX3-J-08) and by The National Natural
Science Foundation of China (Projects 30070185 and
39970864).
D
Compound 21 (161 mg, 0.04 mmol) was acetylated
under the same conditions as that used for the prepara-
tion of 10 from 9, giving 22 (145 mg, 89.5%) as a foamy
1
solid: [a]D
ꢄ
/
36.58 (c 1.0, CHCl3); H NMR (400 MHz,
References
CDCl3, some characteristic signals are given): d 6.19
(dd, 1 H, J3,4 J4,5 9.8 Hz, H-4), 6.12 (dd, 1 H, J3,4
J4,5 9.7 Hz, H-4), 6.10 (dd, 1 H, J3,4 J4,5 9.7 Hz,
H-4), 6.07 (dd, 1 H, J3,4 J4,5 9.7 Hz, H-4), 5.78 (dd,
J1,2 0.6 Hz, J2,3 3.2 Hz, H-2), 5.55 (d, 1 H, J1,2 0.5
ꢂ
/
ꢂ
/
ꢂ
/
1. Hodgson, R.; Peterson, W. H.; Riker, A. J. Phytopathol-
ꢂ
/
ꢂ
/
ꢂ
/
ogy 1949, 39, 47ꢀ
2. Anagnostakis, S. L. Mycologia 1987, 79, 23ꢀ
3. Molinaro, A.; Piscopo, V.; Lanzetta, R.; Parrilli, M.
Carbohydr. Res. 2002, 337, 1707ꢀ1714.
4. (a) Yi, Y.; Zhou, Z.; Ning, J.; Kong, F.; Li, J. Synthesis
2003, 4, 491ꢀ496;
(b) Wang, W.; Kong, F. Tetrahedron Lett. 1998, 1937ꢀ
1940;
/62.
ꢂ
/
ꢂ
/
/
37.
ꢂ
/
ꢂ
/
Hz, H-1), 5.52 (d, 1 H, J1,2 0.8 Hz, H-1), 5.42 (d, 1 H,
J1,2 0.8 Hz, H-1), 5.37 (d, 1 H, J1,2 1.5 Hz, H-1), 5.32
/
(dd, 1 H, J3,4
ꢂ
/
J4,5
ꢂ9.9 Hz, H-4), 5.31 (d, 1 H, J1,2 0.8
/
/
Hz, H-1), 5.16 (d, 1 H, J1,2 1.1 Hz, H-1), 5.13 (d, 1 H,
J1,2 0.9 Hz, H-1), 5.05 (d, 1 H, J1,2 0.9 Hz, H-1), 4.95 (d,
1 H, J1,2 1.2 Hz, H-1), 2.17 (s, 3 H, CH3CO), 2.16 (s, 3
H, CH3CO), 2.08 (s, 3 H, CH3CO), 2.07 (s, 3 H,
CH3CO), 2.03 (s, 3 H, CH3CO), 1.99 (s, 3 H,
CH3CO); 13C NMR (100 MHz, CDCl3): d 171.6,
170.5, 170.3, 170.2, 169.9, 169.6 (6 C, 6 CH3CO),
/
(c) Wang, W.; Kong, F. Carbohydr. Res. 1999, 315, 117ꢀ
127;
(d) Ning, J.; Yi, Y.; Kong, F. Tetrahedron Lett. 2002,
/
5545ꢀ
/
5549.
5. (a) Yang, G.; Kong, F. Synlett 2000, 1423ꢀ1426;
(b) Ning, J.; Zhang, W.; Yi, Y.; Yang, G.; Wu, Z.; Yi, J.;
/
167.2ꢀ/164.9 (PhCO, some signals overlapped), 118.3
Kong, F. Bioorg. Med. Chem. 2003, in press.
(CH2ꢀ/CHCH2O), 100.3, 100.1, 99.8, 99.7, 99.3, 99.0,
6. (a) Ning, J.; Kong, F. Tetrahedron Lett. 1999, 1357ꢀ
(b) Heng, L.; Ning, J.; Kong, F. Carbohydr. Res. 2001,
331, 431ꢀ438;
(c) Ning, J.; Heng, L.; Kong, F. Tetrahedron Lett. 2002,
673ꢀ675.
7. (a) Zhang, J.; Kong, F. Tetrahedron: Asymmetry 2002, 13,
243ꢀ252;
(b) Zhu, Y.; Kong, F. Synlett 2001, 1217ꢀ
(c) Zhu, Y.; Kong, F. Synlett 2000, 1783ꢀ1787;
(d) Du, Y.; Zhang, M.; Kong, F. Tetrahedron 2001, 57,
1757ꢀ1763;
(e) Zhu, Y.; Chen, L.; Kong, F. Chin. J. Chem. 2001, 19,
1289ꢀ1295.
8. (a) Zhu, Y.; Kong, F. Synlett 2000, 663ꢀ
(b) Zhu, Y.; Kong, F. Carbohydr. Res. 2001, 332, 1ꢀ
9. Ogawa, T.; Yamamoto, H. Carbohydr. Res. 1985, 137,
79ꢀ88.
10. Schmidt, R. R.; Kinzy, W. Adv. Carbohydr. Chem.
Biochem. 1994, 50, 21ꢀ125.
/
1360;
98.8, 98.8, 97.7 (9 C, 9 C-1), 22.8, 20.9, 20.9, 20.8, 20.8,
20.4 (6 C, CH3CO). Anal. Calcd for C223H196O74: C,
65.97; H, 4.87. Found: C, 66.14; H, 5.10.
/
/
3.20. Allyl a-
D
-mannopyranosyl-(10
2)-a-
-mannopyranosyl-(103)-a-
/
2)-a-D-
mannopyranosyl-(10
D
/
D
-mannopyranosyl-(10
/
6)-[a-
-mannopyranosyl-(102)-
-mannopyranosyl-(10
-mannopyranoside
/
/
1220;
/
D
/
/
a-
6)-[a-
(23)
D
-mannopyranosyl-(10
/
2)]-a-
D
/
D
-mannopyranosyl-(10
/
2)]-a-
D
/
/
Compound 21 (700 mg, 0.17 mmol) was dissolved in a
satd ammoniaꢀMeOH solution (50 mL). After a week
at rt, the reaction mixture was concentrated, and the
/
667;
/
/21.
residue was purified by chromatography on Sephadex
LH-20 (MeOH) to afford 23 (181 mg, 68.6%) as a syrup:
/
1
[a]D
ꢁ
/
10.58 (c 1.0, H2O); H NMR (400 MHz, D2O,
/