Synthesis of mannose-containing analogues of (1→6)-branched (1→3)-glucohexaose (I)

Article abstract of DOI:10.1016/S0008-6215(03)00263-5

α-D-Manp-(1→3)-[α-D-Manp-(1→6)]-α-D-Glcp- (1→3)-β-D-Glcp-(1→3)-[α-D-Manp-(1→6)]-D-Glcp and α-D-Manp-(1→3)-[β-D-Glcp-(1→6)]-α-D-Glcp- (1→3)-β-D-Glcp-(1→3)[-α-D-Manp-(1→6)]-D-Glcp were synthesized in a regio- and stereoselective way as the mannose-containin

Full text of DOI:10.1016/S0008-6215(03)00263-5

Carbohydrate Research 338 (2003) 1727ꢀ1735
/
www.elsevier.com/locate/carres
Synthesis of mannose-containing analogues of (10
/
6)-branched
(103)-glucohexaose (I)
/
Zicheng Wu, Fanzuo Kong*
Research Center for Eco-Environmental Sciences, Academia Sinica, P.O. Box 2871, Beijing 100085, PR China
Received 14 March 2003; accepted 3 June 2003
Abstract
a-
-Glcp-(10
as the mannose-containing analogues of the immunomodulating b-
(103)-[b- -Glcp-(106)]- -Glcp.
D
-Manp-(10
/
3)-[a-
D
-Manp-(10
/
6)]-a-
D
-Glcp-(10
/
3)-b-
D
-Glcp-(10
6)]- -Glcp were synthesized in a regio- and stereoselective way
-Glcp-(103)-[b- -Glcp-(106)]-a- -Glcp-(103)-b- -Glcp-
/
3)-[a-
D
-Manp-(10
/
6)]-
D
-Glcp and a-
D
-Manp-(10
/
3)-[b-
D
/
6)]-a-
D
-Glcp-(10
/
3)-b- -Glcp-(10
D
/
3)[-a- -Manp-(10
D
/
D
D
/
D
/
D
/
D
/
D
/
D
# 2003 Elsevier Ltd. All rights reserved.
Keywords: Oligosaccharide; Mannose; Glucose
1. Introduction
acid showed antitumor activity.4 However, an interest-
ing result in our research revealed5 that a synthetic
Many biologically active polysaccharides from tradi-
tional herbal medicines that are derived from sources
such as Ganoderma lucidum, Schizophyllum commune
hexasaccharide, b-
-Glcp-(103)-b- -Glcp-(10
Glcp, in combination with the chemotherapeutic agent
cyclophosphamide (CPA), at a dose of 0.5ꢀ1 mg/kg
substantially increased the inhibition of S180 for CPA,
but decreased the toxicity caused by CPA. It was noted
that this hexasaccharide was not fully b-linked like the
repeating unit of letinan6 but contained one a-likage
between the two trisaccharide moieties. This inspired us
to carry out more research regarding the study on
D
-Glcp-(10
/
3)-[b-
D
-Glcp-(10
/
6)]-a-
D
/
D
/
3)-[b-
D
-Glcp-(10
/
6)]-
D-
/
and Lentinus edodes have a b-(10
/
3)-linked glucosyl
6)-branched glucosyl side chains.1
backbone with b-(10
/
Of them, polysaccharides from L. edodes, called lenti-
nan, have the strongest antitumor effect, particularly,
for Sarcoma-180 (S180) in mice and have been used as an
antitumor agent as an immunostimulant in Japan and
China for many years. Clinically, lentinan has proved
effective with chemotherapeutic agents for patients with
recurrent gastric and colorectal cancer. Recent studies
structureꢀfunction relationships of oligosaccharides.
/
We present herein the synthesis of mannose-containing
analogues of the active glucose hexasaccharide.
revealed that a-(10
/
3)-linked glucans also exist in some
medically important fungi such as Cryphonectrini para-
sitica and G. lucidum.2 Some physicochemical and
immunopharmacological investigations show that the
antitumor activity of these glucans may be closely
2. Results and discussion
related to the triplet-helix structures of the b-(10
linked backbone chains.3 It was also reported that only
higher molecular-weight fractions (MWꢀ16,000) ob-
tained from partial hydrolysis of lentinan with formic
/
3)-
To investigate the immunomodulation mechanism in-
duced by the active glucohexaose, b-
-Glcp-(106)]-a- -Glcp-(103)-b- -Glcp-(10
-Glcp-(106)]- -Glcp, a series of structurally different
analogues was needed. We first tried to replace the
nonreducing end b- -Glcp of the (103)-linked back-
bone with an a- -Manp, and also replace the two or one
b- -Glcp branches with a- -Manp, respectively.
D
-Glcp-(10
/
3)-[b
/
-
D
/
D
/
D
/
3)-[-
D
/
D
D
/
* Corresponding author. Tel.: ꢁ
10-62923563.
E-mail address: fzkong@mail.rcees.ac.cn (F. Kong).
/
86-10-62936613; fax: ꢁ86-
/
D
D
D
0008-6215/03/$ - see front matter # 2003 Elsevier Ltd. All rights reserved.
doi:10.1016/S0008-6215(03)00263-5

1728
Z. Wu, F. Kong / Carbohydrate Research 338 (2003) 1727ꢀ1735
/
Scheme 1.
As shown in Scheme 1, a 3,6-mannose branched
trisaccharide donor 9 was obtained in a facile way.
Thus, reaction of 1,2:5,6-di-O-isopropylidene-a- -glu-
cofuranose (2) with 1,2,3,4-tetra-O-benzoyl-a- -manno-
pyranosyl trichloroacetimidate (1)7 smoothly afforded
a-(103)-linked disaccharide 3 (81.3%). Selective re-
moval of the 5,6-O-isopropylidene group of 3 gave the
disaccharide diol acceptor 4 in high yield (96.5%).
Subsequent coupling of 4 with the donor 1 furnished
the trisaccharide 5 (73.1%). Hydrolysis to remove the
1,2-O-isopropylidene group was accompanied by ring
expansion to give the trisaccharide 6, and subsequent
acetylation yielded the trisaccharide 7 (88.1% for two
steps). Selective 1-O-deacetylation of 7 (82.2%), fol-
lowed by trichloroacetimidation7 with trichloroacetoni-
trile in the presence of potassium carbonate, produced
the trisaccharide donor 9.
Acetylation (80.5%), followed by deallylation with
PdCl2, gave the trisaccharide acceptor 19 (77.8%). The
acetylation of the 5-OH of glucofuranose was necessary,
otherwise the subsequent deallylation gave a diol
acceptor whose coupling with 9 did not show regios-
electivity.
D
D
/
With the two donors 9 and 15, and the acceptor 19 in
hand, the hexasaccharides 23 and 27 were readily
assembled (Schemes 3 and 4). Therefore, coupling of
19 with 9 and 15 afforded the hexasaccharides 20
(63.2%) and 24 (76.3%), respectively. It was noted that
both of the couplings showed abnormal8 stereoselectiv-
ity affording a-linked hexasaccharides as indicated from
the C-1III chemical shifts (94.0 ppm) and JC1-H1 values
(172 and 174 Hz, respectively), in spite of the presence of
C-2 neighboring group participation of the donors. This
was the same as we previously reported5 for the coupling
of a 3,6-b-linked glucose trisaccharide acceptor with a
trisaccharide donor with a C-2 ester group, although the
3- or 3,6-glucosyl residues in the donor were replaced
with mannosyl residues in the present case. Hydrolysis
to remove the 1,2-O-isopropylidene group gave 21 and
25, and subsequent acetylation, and deacylation
smoothly furnished the target hexasaccharides 23 and
Scheme 2 outlines the synthesis of the trisaccharide
donor 15 with the only mannose substitution at the
nonreducing end of (10/3)-linked backbone. Thus,
condensation of 4 with perbenzoylated glucopyranosyl
trichloroacetimidate 10 gave the trisaccharide 11 in
satisfactory yield (81.5%). Hydrolysis, acetylation
(87.7% for two steps), selective 1-O-deacetylation, and
trichloroacetimidation (94.7 for two steps) affords the
another trisaccharide donor 15.
27. Compounds 23 and 27 were identified by 1H and 13
C
NMR spectroscopy and mass spectrometry, showing all
of the characteristic signals. Bioassay of the samples is in
progress.
In summary, analogues of the active glucohexaose
bearing two and three mannose units were synthesized
A co-used trisaccharide acceptor for both the donors
9 and 15 was synthesized as shown in Scheme 3. Thus,
selective coupling of the disaccharide acceptor 165 with
the donor 1 furnished the trisaccharide 17 (63.0%).

Z. Wu, F. Kong / Carbohydrate Research 338 (2003) 1727ꢀ
/1735
1729
Scheme 2.
Scheme 3.

1730
Z. Wu, F. Kong / Carbohydrate Research 338 (2003) 1727ꢀ
/1735
Scheme 4.
in an efficient way. Large-scale preparations should be
possible with this method.
HPLC consisting of a pump (model 306), stainless steel
column packed with silica gel (Spherisorb SiO2, 10ꢂ
or 4.6ꢂ250 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. Experimental
/
/
3.1. General methods
Melting points (mp) were determined with a ‘Mel-Temp’
apparatus. Optical rotations were determined with a
3.2. 2,3,4,6-Tetra-O-benzoyl-a-
3)-1,2:5,6-di-O-isopropylidene-a-
D
-mannopyranosyl-(10
/
D
-glucofuranose (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-
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 operating in the
electrospray-ionization (ESI) mode. Thin-layer chroma-
tography (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
2,3,4,6-Tetra-O-benzoyl-a-
oacetimidate (1) (499 mg, 0.674 mmol) and 1,2:5,6-di-
-glucofuranose (2) (174 mg, 0.669
mmol) were dried together under high vacuum for 2 h,
then dissolved in anhyd CH2Cl2 (10.0 mL). TMSOTf
D-mannopyranosyl trichlor-
O-isopropylidene-a-
D
(10.0 mL, 0.087 mmol) was added dropwise at ꢃ20 8C
/
with N2 protection. The reaction mixture was stirred for
3 h, during which time the temperature was gradually
raised to ambient temperature. The mixture was then
neutralized with Et3N. Concentration of the reaction
mixture, followed by purification on a silica gel column
was conducted by elution of a column (8ꢂ
240, 18ꢂ300, 35ꢂ400 mm) of silica gel (100ꢀ
mesh) with petroleum etherꢀEtOAc (bp 60ꢀ90 8C) as
the eluent. Analytical LC was performed with a Gilson
/
100, 16ꢂ
/
/
/
/200
with 3:1 petroleum etherꢀ
/
EtOAc as the eluent gave the
158 (c 1.0,
CHCl3); H NMR (CDCl3, 400 MHz): d 8.12ꢀ7.26 (m,
/
/
product 3 (561 mg, 81.3%) as a syrup: [a]D
ꢁ
/
1
/

Z. Wu, F. Kong / Carbohydrate Research 338 (2003) 1727ꢀ
/1735
1731
20 H, Bzꢀ
4?), 6.02 (d, 1 H, J1,2 3.0 Hz, H-1), 5.88 (dd, J2?,3? 3.3 Hz,
3?,4? 10.0 Hz, H-3?), 5.76 (dd, 1 H, J1?,2? 1.7 Hz, J2?,3? 3.3
Hz, H-2?), 5.41 (d, 1 H, J1?,2? 1.7 Hz, H-1?), 4.73ꢀ4.69
(m, 2 H, H-6?, H-3), 4.56ꢀ4.51 (m, 2 H, H-6?, H-5), 4.44
(d, 1 H, J2,3 2.8 Hz, H-2), 4.35ꢀ4.30 (m, 1 H, H-5), 4.23
(dd, 1 H, J 6.2, J 8.6 Hz), 4.11 (dd, 1 H, J 2.8, J 8.8 Hz),
4.01 (dd, 1 H, J 4.0, J 8.6 Hz, H-6), 1.50, 1.38, 1.31, 1.28
(s, 12 H, 4 CH3). Anal. Calcd for C46H46O15: C, 65.87;
H, 5.49. Found: C, 65.91; H, 5.44.
/
H), 6.06 (dd, 1 H, J3?,4?ꢄ
/
J
4?,5?ꢄ
/
10.0 Hz, H-
3.5. 2,3,4,6-Tetra-O-benzoyl-a-
3)-[2,3,4,6-tetra-O-benzoyl-a- -mannopyranosyl-(10
6)]-1,2,4-tri-O-acetyl- -glucopyranoside (7)
D
-mannopyranosyl-(10
/
D
/
J
D
/
/
A solution of 5 (3.00 g, 2.15 mmol) in 90% CF3COOH
(20 mL) was stirred for 2 h at room temperature (rt),
then concentrated to dryness. The residue was dissolved
in Py (30 mL), and then Ac2O (6 mL) was added. After
stirring the mixture at rt for 12 h, TLC (2:1 petroleum
/
etherꢀEtOAc) indicated that the reaction was complete.
/
The reaction mixture was extracted with CH2Cl2 (50
mL), washed with dil HCl and satd aq NaHCO3. The
organic phase was dried over anhyd Na2SO4, then
concentrated to dryness. Purification by silica gel
3.3. 2,3,4,6-Tetra-O-benzoyl-a-
3)-1,2-O-isopropylidene-a-D-glucofuranose (4)
D
-mannopyranosyl-(10
/
column chromatography (2:1 petroleum etherꢀEtOAc)
/
gave 7 (2.80 g, 88.1% for two steps) as a syrupy
anomeric mixture. The a-anomer was the major product
To a solution of 90% HOAc (20 mL) was added 3 (1.20
g, 1.43 mmol), and the mixture was stirred at 40 8C
overnight, then concentrated to dryness. The residue
was passed through a short silica column (1:1 petroleum
isolated in pure form and characterized: [a]D
ꢃ
/
1.58 (c
1.0, CHCl3); H NMR (CDCl3, 400 MHz): d 8.15ꢀ7.26
(m, 40 H, BzꢀH), 6.39 (d, 1 H, J1,2 3.8 Hz, H-1), 6.30ꢀ
6.25 (m, 2 H, 2 H-4), 6.15ꢀ6.05 (m, 2 H, 2 H-3), 5.94ꢀ
5.86 (m, 2 H, 2 H-2), 5.32 (d, 1 H, J1,2 1.7 Hz, H-1),
5.27ꢀ5.15 (m, 1 H), 5.10 (d, 1 H, J1,2 1.7 Hz, H-1), 4.84ꢀ
4.81 (m, 1 H), 4.53ꢀ4.42 (m, 2 H), 4.39ꢀ4.31 (m, 2 H),
4.16ꢀ4.11 (m, 1 H), 4.06ꢀ4.02 (m, 1 H), 3.97ꢀ3.88 (m, 3
H), 3.77ꢀ3.68 (m, 1 H), 2.34, 2.24, 2.15 (s, 9 H, 3
CH3CꢁO). Anal. Calcd for C80H70O27: C, 65.66; H,
4.79. Found: C, 66.92; H, 4.57.
1
/
/
/
etherꢀ
144ꢀ146 8C; [a]D
(CDCl3, 400 MHz): d 8.09ꢀ
6.06 (dd, 1 H, J3?,4?ꢄ 4?,5?ꢄ9.9 Hz, H-4?), 6.02 (d, 1 H,
J1,2 2.7 Hz, H-1), 5.86 (dd, J2?,3? 3.0 Hz, J3?,4? 9.9 Hz, H-
/
EtOAc) to give 4 (1.10 g, 93%) as crystals: mp
178 (c 1.0, CHCl3); 1H NMR
7.26 (m, 20 H, BzꢀH),
/
/
/
ꢁ
/
/
/
/
/
/J
/
/
/
/
/
/
3?), 5.76 (m, 1 H, H-2?), 5.41 (s, 1 H, H-1?), 4.72ꢀ
(m, 2 H, H-6?, H-3), 4.55ꢀ
4.24 (m, 1 H, H-5), 4.15ꢀ
/
4.67
/
/
4.49 (m, 3 H, H-6?, H-5?, H-2),
/
/
4.11 (m, 1 H, H-6), 4.00ꢀ
/
3.98
(m, 1 H, H-6), 3.80 (dd, 1 H, J 10.0, J 4.8 Hz), 1.49, 1.32
(s, 6 H, 2 CH3). Anal. Calcd for C43H42O15: C, 64.66; H,
5.30. Found: C, 64.92; H, 5.18.
3.6. 2,3,4,6-Tetra-O-benzoyl-a-
3)-[2,3,4,6-tetra-O-benzoyl-a- -mannopyranosyl-(10
6)]-2,4-di-O-acetyl- -glucopyranose (8)
D
-mannopyranosyl-(10
/
D
/
D
3.4. 2,3,4,6-Tetra-O-benzoyl-a-
3)-[2,3,4,6-tetra-O-benzoyl-a- -mannopyranosyl-(10
6)]-1,2-O-isopropylidene-a- -glucofuranose (5)
D
-mannopyranosyl-(10
/
Compound 7 (2.50 g, 1.69 mmol) was dissolved in THF
(30 mL), and then benzyl amine (1 mL) was added. The
mixture was stirred at rt until TLC (2:1 petroleum
D
/
D
etherꢀEtOAc) indicated that the reaction was complete.
/
Compound 5 was prepared by coupling of 1 (800 mg,
1.08 mmol) with 4 (860 mg, 1.08 mmol) under the same
conditions as described for the synthesis of 3 by
coupling of 1 with 2. Concentration of the reaction
mixture, followed by purification on a silica gel column
The mixture was extracted with CH2Cl2 (50 mL),
washed with dil HCl and satd aq NaHCO3. The organic
phase was dried over anhyd Na2SO4, then concentrated
to dryness. Purification by silica gel column chromato-
graphy (2:1 petroleum etherꢀ
82.2%) as a syrupy anomeric mixture, of which the
major a-anomer was characterized: [a]D 12.58 (c 1.0,
CHCl3); H NMR (CDCl3, 400 MHz): d 8.14ꢀ7.26 (m,
40 H, BzꢀH), 6.21 (dd, 1 H, J3,4 J4,5 10.2 Hz, H-4),
6.06 (dd, 1 H, J3,4 J4,5 10.1 Hz, H-4), 5.93 (dd, 1 H,
J2,3 3.3 Hz, J3,4 10.1 Hz, H-3), 5.80 (dd, 1 H, J2,3 3.2 Hz,
J3,4 10.2 Hz, H-3), 5.73ꢀ5.71 (m, 1 H, H-2), 5.56 (d, 1 H,
J1,2 1.6 Hz, H-1), 5.55 (m, 1 H, H-2), 5.34 (d, 1 H, J1,2
1.6 Hz, H-1), 5.16ꢀ5.11 (m, 2 H, H-1, H-4), 4.99 (dd, 1
H, J1,2 3.5 Hz, J2,3 9.9 Hz, H-2), 4.91ꢀ4.80 (m, 2 H),
4.76ꢀ4.73 (m, 1 H), 4.64ꢀ4.60 (m, 1 H), 4.56ꢀ4.55 (m, 1
H), 4.52ꢀ4.34 (m, 3 H), 4.34ꢀ4.32 (m, 1 H), 4.20ꢀ4.09
(m, 1 H), 4.00ꢀ3.90 (m, 1 H), 3.76ꢀ3.70 (m, 1 H), 2.29,
2.20 (s, 6 H, 2 CH3Cꢁ
O); 13C NMR: d 169.64, 169.56 (2
/EtOAc) gave 8 (2.00 g,
with 2:1 petroleum etherꢀ
/
EtOAc as the eluent, gave the
78 (c 1.0,
CHCl3); H NMR (CDCl3, 400 MHz): d 8.09ꢀ7.22 (m,
40 H, BzꢀH), 6.17 (dd, 1 H, J3,4 J4,5 10.1 Hz, H-4),
6.10 (dd, 1 H, J3,4 J4,5 10.0 Hz, H-4), 6.04 (d, 1 H, J
3.7 Hz, H-1), 5.96ꢀ5.90 (m, 2 H, 2 H-3), 5.81 (dd, 1 H, J
1.7 Hz, J2,3 3.2 Hz, H-2), 5.74 (dd, 1 H, J1,2 1.7 Hz,
product 5 (1.10 g, 73.1%) as a syrup: [a]D
ꢃ
/
ꢁ
/
1
1
/
/
/
ꢄ
/
ꢄ
/
/
ꢄ
/
ꢄ
/
ꢄ
/
ꢄ
/
ꢄ
/
ꢄ
/
/
/
1,2
J2,3 3.2 Hz, H-2), 5.53 (d, 1 H, J1,2 1.7 Hz, H-1), 5.21 (d,
1 H, J1,2 1.7 Hz, H-1), 4.77ꢀ4.65 (m, 4 H), 4.58ꢀ4.51 (m,
4 H), 4.40 (dd, 1 H, J5,6 2.6 Hz, J6,6 9.6 Hz, H-6), 4.34ꢀ
4.30 (m, 1 H, H-5), 4.17ꢀ4.11 (m, 1 H, H-6), 3.97 (dd, 1
/
/
/
/
/
/
/
/
/
H, J5,6 2.6 Hz, J6,6 10.1 Hz, H-6), 1.51, 1.25 (s, 6 H, 2
CH3). Anal. Calcd for C77H68O24: C, 67.15; H, 4.98.
Found: C, 66.92; H, 5.13.
/
/
/
/
/
/

1732
Z. Wu, F. Kong / Carbohydrate Research 338 (2003) 1727ꢀ1735
/
CH3C ꢁ
/
O), 166.3, 165.9, 165.6, 165.5, 165.1, 165.0,
5.67 (dd, 1 H, J2,3
ꢄ
/
J3,4
J1,2 8.9 Hz, J2,3 10.2 Hz, H-2), 5.45 (d, 1 H, J1,2 1.2 Hz,
ꢄ9.7 Hz, H-3), 5.57 (dd, 1 H,
/
164.9, 164.7 (8 C, 8 COPh), 98.7, 98.3, 97.4 (C-1IꢀIII),
89.8 (C-3), 72.7, 72.2, 70.7, 70.4, 70.2, 69.9, 69.7, 69.4,
69.2, 68.66, 67.9, 66.8, 62.5, 62.2 (C-2,-3,-4,-5,-6IꢀIII).
Anal. Calcd for C78H68O26: C, 65.45; H, 5.45. Found: C,
65.27; H, 5.64.
H-1), 5.00 (d, 1 H, J1,2 8.9 Hz, H-1), 4.76 (dd, 1 H, J5,6
2.6 Hz, J6,6 12.4 Hz, H-6), 4.70ꢀ
(m, 3 H), 4.40 (dd, 1 H, J5,6 5.0 Hz, J6,6 12.4 Hz, H-6),
4.27ꢀ4.25 (m, 1 H, H-5), 4.18ꢀ4.16 (m, 3 H), 3.99ꢀ3.95
(m, 1 H), 1.43, 1.26 (s, 6 H, 2 CH3CꢁO). Anal. Calcd for
C77H68O24: C, 67.15; H, 4.98. Found: C, 67.39; H, 5.23.
/
4.67 (m, 2 H), 4.55ꢀ4.46
/
/
/
/
/
3.7. 2,3,4,6-Tetra-O-benzoyl-a-
3)-[2,3,4,6-tetra-O-benzoyl-a- -mannopyranosyl-(10
6)]-2,4-di-O-acetyl-a- -glucopyranosyl
trichloroacetimidate (9)
D
-mannopyranosyl-(10
/
D
/
D
3.9. 2,3,4,6-Tetra-O-benzoyl-a-
3)-[2,3,4,6-tetra-O-benzoyl-b- -glucopyranosyl-(10
1,2,4-tri-O-acetyl- -glucopyranose (13)
D
-mannopyranosyl-(10
/
D
/6)]-
D
Compound 8 (2.00 g, 1.39 mmol) was dissolved in
CH2Cl2 (20 mL), then CCl3CN (0.1 mL, 2.0 mmol) and
K2CO3 (1.0 g, 7.0 mmol) was added. The reaction
mixture was stirred for 10 h, at the end of which time
A solution of 11 (3.00 g, 2.15 mmol) in 90% CF3COOH
(20 mL) was stirred for 2 h at rt, then concentrated to
dryness. The residue was dissolved in Py (30 mL), and
then Ac2O (6 mL) was added. After stirring the mixture
TLC (3:1 petroleum etherꢀEtOAc) indicated that the
/
reaction was complete. The mixture was filtered, and the
filtrate was concentrated. The residue was purified by
at rt for 12 h, TLC (2:1 petroleum etherꢀEtOAc)
/
indicated that the reaction was complete. The reaction
mixture was extracted with CH2Cl2 (50 mL), washed
with dil HCl and satd aq NaHCO3. The organic phase
was dried over anhyd Na2SO4, then concentrated to
dryness. Purification by silica gel column chromatogra-
flash chromatography (3:1 petroleum etherꢀ
give 9 (2.00 g, 92.1%) as a syrup: [a]D 2.58 (c 1.0,
CHCl3); H NMR (CDCl3, 400 MHz): d 8.90 (s, 1 H,
CꢁNH), 8.33ꢀ7.29 (m, 40 H, BzꢀH), 6.56 (d, 1 H, J1,2
3.8 Hz, H-1), 6.35 (dd, 1 H, J3,4 J4,5 10.2 Hz, H-4),
6.09 (dd, 1 H, J3,4 J4,5 10.1 Hz, H-4), 5.88 (dd, 1 H,
/EtOAc) to
ꢁ
/
1
/
/
/
ꢄ
/
ꢄ
/
phy (2:1 petroleum etherꢀ
for two steps) as a syrupy anomeric mixture, of which
the major a-anomer was characterized: [a]D ꢁ358 (c 1.0,
CHCl3); H NMR (CDCl3, 400 MHz): d 7.99ꢀ7.27 (m,
40 H, BzꢀH), 6.35 (d, 1 H, J1,2 3.6 Hz, H-1), 6.25 (dd, 1
H, J3,4 J4,5 10.2 Hz, H-4), 5.76 (dd, 1 H, J2,3 3.1, J3,4
10.3 Hz, H-3), 5.70ꢀ5.53 (m, 3 H), 5.38 (dd, 1 H, J3,4
J4,5 10.0 Hz), 5.32ꢀ5.18 (m, 3 H), 4.83ꢀ4.77 (m, 1 H),
4.43ꢀ4.25 (m, 5 H), 4.16ꢀ4.01 (m, 4 H), 2.29, 2.15, 2.14
(s, 9 H, 3 CH3CꢁO). Anal. Calcd for C80H70O27: C,
65.66; H, 4.79. Found: C, 66.85; H, 4.52.
/EtOAc) gave 13 (2.70 g, 84.7%
ꢄ
/
ꢄ
/
J2,3 3.3 Hz, J3,4 10.2 Hz, H-3), 5.78 (dd, 1 H, J2,3 3.1 Hz,
J3,4 10.1 Hz, H-3), 5.68 (dd, 1 H, J1,2 1.6 Hz, J2,3 3.3 Hz,
/
1
/
H-2), 5.60 (dd, 1 H, J
1.6 Hz, J2,3 3.1 Hz, H-2), 5.32
/
1,2
(d, 1 H, J 1.6 Hz, H-1), 5.24ꢀ
J 1.6 Hz, H-1), 4.78ꢀ4.74 (m, 2 H), 4.64ꢀ
4.56ꢀ4.52 (m, 1 H), 4.44ꢀ4.37 (m, 3 H), 4.29ꢀ
H), 3.98ꢀ3.95 (m, 1 H), 3.73ꢀ3.70 (m, 1 H), 2.34, 2.16 (s,
6 H, 2 CH3CꢁO). Anal. Calcd for C80H68Cl3NO26: C,
61.37; H, 4.38. Found: C, 61.53; H, 4.51.
/
5.20 (m, 2 H), 5.10 (d, 1 H,
4.58 (m, 1 H),
4.22 (m, 1
ꢄ
/
ꢄ
/
/
/
/
ꢄ
/
/
/
/
ꢄ
/
/
/
/
/
/
/
/
/
3.8. 2,3,4,6-Tetra-O-benzoyl-a-
3)-[2,3,4,6-tetra-O-benzoyl-b- -glucopyranosyl-(10
1,2-O-isopropylidene-a- -glucofuranose (11)
D
-mannopyranosyl-(10
/
3.10. 2,3,4,6-Tetra-O-benzoyl-a-
(103)-[2,3,4,6-tetra-O-benzoyl-b-
6)]-2,4-di-O-acetyl- -glucopyranose (14)
D
-mannopyranosyl-
-glucopyranosyl-(10
D
/6)]-
/
D
/
D
D
2,3,4,6-Tetra-O-benzoyl-a-
D
-mannopyranosyl trichlor-
Compound 13 (2.5 g, 1.69 mmol) was dissolved in THF
(30 mL), and then benzyl amine (1 mL) was added. The
mixture was stirred at rt until TLC (2:1 petroleum ether
oacetimidate 10 (3.00 g, 4.05 mmol) and 4 (3.23 g,
4.05 mmol) were dried together under high vacuum for 2
h, then dissolved in anhyd CH2Cl2 (50 mL). TMSOTF
etherꢀEtOAc) indicated that the reaction was complete.
/
(15 mL, 0.131 mmol) was added dropwise at ꢃ
/
20 8C
The mixture was extracted with CH2Cl2 (50 mL),
washed with dil HCl and satd aq NaHCO3. The organic
phase was dried over anhyd Na2SO4, then concentrated
to dryness. Purification by silica gel column chromato-
with N2 protection. The reaction mixture was stirred for
3 h, during which time the temperature was gradually
raised to ambient temperature. Then the mixture was
neutralized with Et3N. Concentration of the reaction
mixture, followed by purification on a silica gel column
graphy (2:1 petroleum etherꢀ
82.2%) as a syrupy anomeric mixture, of which the
major a-anomer was characterized: [a]D 30.58 (c 1.0,
CHCl3); H NMR (CDCl3, 400 MHz): d 8.25ꢀ7.26 (m,
40 H, BzꢀH), 6.22 (dd, 1 H, J3,4 J4,5 10.0 Hz, H-4),
6.12 (dd, 1 H, J3,4 J4,5 10.0 Hz, H-4), 5.95 (dd, 1 H,
/EtOAc) gave 14 (2.00 g,
with 2:1 petroleum etherꢀ
/
EtOAc as the eluent, gave the
248 (c 1.0,
CHCl3); H NMR (CDCl3, 400 MHz): d 7.98ꢀ7.25 (m,
40 H, BzꢀH), 6.03 (dd, 1 H, J3,4 J4,5 10.0 Hz, H-4),
5.99 (d, 1 H, J1,2 3.4 Hz, H-1), 5.91 (dd, 1 H, J3,4
J4,5 9.7 Hz, H-4), 5.86 (dd, 1 H, J2,3 3.3 Hz, J3,4 10.2
Hz, H-3), 5.73 (dd, 1 H, J1,2 1.2 Hz, J2,3 4.8 Hz, H-2),
ꢁ
/
1
product 11 (4.60 g, 81.5%) as a syrup: [a]D
ꢁ
/
/
1
/
/
ꢄ
/
ꢄ
/
/
ꢄ
/
ꢄ
/
ꢄ
/
ꢄ
/
ꢄ
/
J2,3 3.2 Hz, J3,4 10.0 Hz, H-3), 5.82 (m, 1 H, H-3), 5.73
(m, 1 H, H-2), 5.57 (m, 2 H, H-1, H-2), 5.41 (d, 1 H,
ꢄ
/
J1,2
ꢄ1.6 Hz, H-1), 5.16 (d, 1 H, J1,2 7.8 Hz, H-1), 4.91
/

Z. Wu, F. Kong / Carbohydrate Research 338 (2003) 1727ꢀ
/1735
1733
ꢀ
/
4.28 (m, 7 H), 4.03ꢀ
2.32, 2.25 (s, 6 H, 2 CH3Cꢁ
(2 CH3C ꢁO), 166.2, 166.1, 166.1, 165.7, 165.6, 165.5,
/
3.93 (m, 1 H), 3.81ꢀ
/
3.70 (m, 1 H),
CHCH2O), 4.21ꢀ
CH2ꢁCHCH2O), 3.72ꢀ
1.56, 1.27 (s, 15 H, 5 CH3Cꢁ
C58H62O23: C, 61.81; H, 5.54. Found: C, 61.51; H, 5.72.
/
4.08 (m, 5 H), 3.92ꢀ
/
3.82 (m, 1 H,
/
O); 13C NMR: d 170.2, 170.0
/
/3.59 (m, 2 H), 2.17, 2.13, 2.11,
/
/
O). Anal. Calcd for
165.4, 165.3 (8 C, 8 COPh), 100.1, 99.4, 97.6 (C-1IꢀIII),
89.3 (C-3), 73.7, 71.4, 70.9, 70.7, 70.3, 69.9, 69.8, 69.5,
69.1, 66.9, 66.7, 66.2, 62.9, 62.1 (C-2,-3,-4,-5,-6IꢀIII).
Anal. Calcd for C80H68Cl3NO26: C, 61.37; H, 4.38.
Found: C, 61.27; H, 4.54.
3.13. 3-O-Allyl-2,4,6-tri-O-acetyl-b-
(103)-[2,3,4,6-tetra-O-benzoyl-a- -mannopyranosyl-
(106)]-5-O-acetyl-1,2-O-isopropylidene-a-
glucofuranose (18)
D-glucopyranosyl-
/
D
/
D-
3.11. 2,3,4,6-Tetra-O-benzoyl-a-
(103)-[2,3,4,6-tetra-O-benzoyl-b-
6)]-2,4-di-O-acetyl-a- -glucopyranosyl
trichloroacetimidate (15)
D
-mannopyranosyl-
-glucopyranosyl-(10
/
D
/
Compound 17 (3.00 g, 2.66 mmol) was dissolved in Py
(50 mL), and then Ac2O (15 mL) was added. After
D
stirring the mixture at 60ꢀ
/
70 8C for 24 h, TLC (2:1
petroleum etherꢀEtOAc) indicated that the reaction was
/
Compound 14 (3.00 g, 2.09 mmol) was dissolved in
CH2Cl2 (30 mL), then CCl3CN (0.5 mL, 5 mmol) and
K2CO3 (1.00 g, 7.00 mmol) was added. The reaction
mixture was stirred for 10 h, at the end of which time
complete. The reaction mixture was extracted with
CH2Cl2 (50 mL) and then washed with dil HCl and
satd aq NaHCO3. The organic phase was dried over
anhyd Na2SO4, then concentrated to dryness. Purifica-
tion by silica gel column chromatography (2:1 petro-
TLC (3:1 petroleum etherꢀEtOAc) indicated that the
/
reaction was complete. The mixture was filtered, and the
filtrate was concentrated. The residue was purified by
leum etherꢀ
[a]D
1.58 (c 1.0, CHCl3); 1H NMR (CDCl3, 400
MHz): d 8.15ꢀ7.26 (m, 20 H, BzꢀH), 6.16 (dd, 1 H,
J3,4 J4,5 10.1 Hz, H-4), 5.93 (d, 1 H, J 3.2 Hz, H-1),
5.85 (dd, 1 H, J2,3 3.2 Hz, J3,4 10.4 Hz, H-3), 5.77ꢀ5.75
(m, 1 H, CH2ꢁCH ꢀCH2O), 5.51 (dd, 1 H, J1,2 1.7 Hz,
J2,3 3.3 Hz, H-2), 5.32 (dd, 1 H, J1,2 7.8 Hz, J2,3 9.6 Hz,
H-2), 5.10 (d, 1 H, J1,2 1.6 Hz, H-1), 4.97ꢀ4.93 (dd, 1 H,
4.82 (dd, 1 H, J4,5
9.5 Hz, H-5), 4.80 (m, 1 H, CH2ꢁCHCH2O),
4.68 (m, 2 H), 4.66ꢀ4.62 (m, 1 H, CH2ꢁ
CHCH2O), 4.58 (d, 1 H, J1,2 7.8 Hz, H-1), 4.57ꢀ4.48
(m, 2 H), 4.39ꢀ4.30 (m, 1 H), 4.28ꢀ4.19 (m, 1 H, CH2ꢁ
CHCH2O), 4.18ꢀ4.06 (m, 2 H), 3.93ꢀ3.85 (m, 1 H),
3.71ꢀ3.68 (m, 1 H), 3.68ꢀ3.56 (m, 1 H, CH2ꢁ
/
EtOAc) gave 18 (2.50 g, 80.5%) as a syrup:
ꢃ
/
flash chromatography (3:1 petroleum ether etherꢀ
EtOAc) to give 15 (3.10 g, 94.7%) as a syrup: [a]D
408 (c 1.0, CHCl3); 1H NMR (CDCl3, 400 MHz): d 8.39
(s, 1 H, CꢁNH), 8.11ꢀ7.27 (m, 40 H, BzꢀH), 6.40 (d, 1
H, J1,2 3.3 Hz, H-1), 6.23 (dd, 1 H, J3,4 J4,5 10.0 Hz,
H-4), 5.88 (dd, 1 H, J3,4 J4,5 9.5 Hz, H-4), 5.72ꢀ5.63
(m, 2 H, 2 H-3), 5.53ꢀ5.50 (m, 2 H, 2 H-2), 5.17 (d, 1 H,
J1,2 1.2 Hz, H-1), 5.10 (dd, 1 H, J3,4 J4,5 10.1 Hz, H-
4), 5.03 (dd, 1 H, J 3.5, J 9.9 Hz), 4.97 (d, 1 H, J1,2 7.8
Hz, H-1), 5.05ꢀ4.95 (m, 2 H), 4.73ꢀ4.65 (m, 2 H), 4.52ꢀ
4.42 (m, 2 H), 4.52ꢀ4.26 (m, 2 H), 4.00 (d, 1 H, J5,6 7.9
Hz, H-6), 3.74 (dd, 1 H, J5,6 5.4 Hz, H-6), 2.25, 2.07 (s, 6
H, 2 CH3CꢁO). Anal. Calcd for C80H68Cl3NO26: C,
61.37; H, 4.38. Found: C, 61.55; H, 4.22.
/
/
/
ꢁ
/
ꢄ
/
ꢄ
/
/
/
/
/
/
/
ꢄ
/
ꢄ
/
ꢄ
/
ꢄ
/
/
/
/
J3,4
J5,6
4.74ꢀ
ꢄ/J4,5
ꢄ
/
9.6 Hz, H-4), 4.87ꢀ
/
ꢄ
/
ꢄ
/
ꢄ
/
ꢄ
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
CHCH2O), 2.15, 2.12, 2.10, 2.03 (s, 12 H, 4 CH3Cꢁ
/
O), 1.62, 1.43 (s, 6 H, 2 CH3). Anal. Calcd for
C60H64O24: C, 61.64; H, 5.48. Found: C, 61.53; H, 5.71.
3.12. 3-O-Allyl-2,4,6-tri-O-acetyl-b-
(103)-[2,3,4,6-tetra-O-benzoyl-a- -mannopyranosyl-
(106)]-1,2-O-isopropylidene-a- -glucofuranose (17)
D-glucopyranosyl-
/
D
/
D
3.14. 2,4,6-Tri-O-acetyl-b-
[2,3,4,6-tetra-O-benzoyl-a-
O-acetyl-1,2-O-isopropylidene-a-
D
-glucopyranosyl-(10
-mannopyranosyl-(10
-glucofuranose (19)
/
3)-
D
/6)]-5-
Compound 17 was prepared by coupling of 1 (4.70 g,
6.35 mmol) with 16 (3.48 g, 6.35 mmol) under the same
conditions as described for the synthesis of 8 by
coupling of 7 with 3. Concentration of the reaction
mixture, followed by purification on a silica gel column
D
To a solution of 18 (2.00 g, 1.71 mmol) in MeOH (20
mL) was added PdCl2 (150 mg, 0.847 mmol). After
stirring the mixture for 3 h at rt, TLC (3:2 petroleum
with 2:1 petroleum etherꢀ
/
EtOAc as the eluent, gave the
178 (c 1.0,
CHCl3); H NMR (CDCl3, 400 MHz): d 8.15ꢀ7.27 (m,
20 H, BzꢀH), 6.17 (dd, 1 H, J3,4 J4,5 10.2 Hz, H-4),
5.91ꢀ5.83 (m, 1 H, CH2ꢁCH ꢀCH2O), 5.79 (dd, 1 H,
J3,4 J4,5 10.2 Hz, H-4), 5.76 (d, 1 H, Jꢄ3.7 Hz, H-
1), 5.68 (dd, 1 H, J1,2 1.7 Hz, J2,3 9.6 Hz, H-2), 5.62ꢀ5.58
(m, 2 H, 2 H-3), 5.36ꢀ5.20 (m, 1 H, CH2ꢁCHCH2O),
5.17 (d, 1 H, J1,2 1.7 Hz, H-1), 5.11ꢀ5.00 (m, 1 H, CH2ꢁ
CHCH2O), 4.73ꢀ4.59 (m, 4 H), 4.58 (d, 1 H, J1,2 7.9 Hz,
H-1), 4.54ꢀ4.42 (m, 3 H), 4.26ꢀ4.23 (m, 1 H, CH2ꢁ
etherꢀEtOAc) indicated that the reaction was complete.
The mixture was filtered, the solution was concentrated
to dryness, and the resultant residue was purified by
/
product 17 (4.50 g, 63.0%) as a syrup: [a]D
ꢃ
/
1
/
/
ꢄ
/
ꢄ
/
flash chromatography (1:1 petroleum etherꢀ
give 19 (1.50 g, 77.8%) as a syrup: [a]D 158 (c 1.0,
CHCl3); H NMR (CDCl3, 400 MHz): d 8.16ꢀ7.25 (m,
20 H, BzꢀH), 6.14 (dd, 1 H, J3,4 J4,5 10.2 Hz, H-4),
/EtOAc) to
/
/
/
ꢃ
/
1
ꢄ
/
ꢄ
/
/
/
/
/
ꢄ
/
ꢄ
/
/
/
5.89 (dd, 1 H, J2,3 3.2 Hz, J3,4 9.6 Hz, H-3), 5.85 (d, 1 H,
J1,2 3.2 Hz, H-1), 5.76 (dd, 1 H, J1,2 1.6 Hz, J2,3 3.1 Hz,
/
/
/
H-2), 5.29 (dd, 1 H, J1,2 7.9 Hz, J2,3 10.2 Hz, H-2), 5.26ꢀ
/
/
/
/
5.23 (m, 1 H, H-5), 5.18 (d, 1 H, J1,2 1.7 Hz, H-1), 4.95

1734
Z. Wu, F. Kong / Carbohydrate Research 338 (2003) 1727ꢀ1735
/
(dd, 1 H, J3,4
ꢄ
/
J4,5
ꢄ
/
9.6 Hz, H-4), 4.85 (dd, 1 H, J4,5
4.71 (m, 2 H), 4.66ꢀ4.62 (m, 1
H), 4.63 (d, 1 H, J1,2 7.9 Hz, H-1), 4.57ꢀ4.48 (m, 2 H),
4.39 (d, 1 H, J5,6 5.2 Hz, H-6), 4.28ꢀ4.19 (m, 1 H), 4.18ꢀ
4.06 (m, 2 H), 3.93ꢀ3.85 (m, 1 H, H-6), 3.73ꢀ3.70 (m, 1
H), 3.68ꢀ3.56 (m, 1 H), 2.12, 2.10, 2.10, 2.09 (s, 12 H, 4
CH3Cꢁ
O), 1.55, 1.33 (s, 6 H, 2 CH3); 13C NMR: d
170.6, 170.3, 169.9, 169.7 (4 CH3C ꢁO), 166.2, 165.4,
ꢄ
/
C135H126O49: C, 64.03; H, 5.01. Found: C, 64.31; H,
4.84.
J5,6
ꢄ
/
9.5 Hz, H-5), 4.80ꢀ
/
/
/
/
/
3.16. a-
syl-(10
syl-(10
D
-Mannopyranosyl-(10
/
3)-[a-
-glucopyranosyl-(103)-b-
-mannopyranosyl-(106)]-b-
D
-mannopyrano-
-glucopyrano-
-gluco-
/
/
/6)]-a-
D
/
D
/
/3)-[a-
D
/
D
/
pyranose (23)
/
165.4, 165.3 (4 C, 4 COPh), 105.1, 98.3, 97.0 (3 C,C-
1IꢀIII), 82.5, 79.2, 73.8, 73.6, 72.2, 70.7, 70.3, 68.8, 68.4,
66.6, 65.9, 62.7, 62.2, 60.3 (C-2,-3,-4,-5,-6IꢀIII). Anal.
Calcd for C57H60O24: C, 60.64; H, 5.36. Found: C,
60.38; H, 5.57.
A solution of 20 (500 mg, 0.198 mmol) in 90%
CF3COOH (5 mL) was stirred for 2 h at rt until TLC
(1:1 petroleum etherꢀEtOAc) indicated that the reaction
/
was complete. The mixture was then concentrated to
dryness. The residue was dissolved in Py (10 mL) and
Ac2O (5 mL) was added. After stirring the mixture at rt
for 12 h, TLC (2:1 petroleum etherꢀEtOAc) indicated
/
3.15. 2,3,4,6-Tetra-O-benzoyl-a-
(103)-[2,3,4,6-tetra-O-benzoyl-a-
(106)]-2,4-di-O-acetyl-a- -glucopyranosyl-(10
2,4,6-tri-O-acetyl-b- -glucopyranosyl-(103)-[2,3,4,6-
tetra-O-benzoyl-a- -mannopyranosyl-(106)]-5-O-
acetyl-1,2-O-isopropylidene-a- -glucofuranose (20)
D
-mannopyranosyl-
-mannopyranosyl-
3)-
that the reaction was complete. The reaction mixture
was extracted with CH2Cl2 (50 mL) and then washed
with dil HCl and satd aq NaHCO3. The organic phase
was dried over anhyd Na2SO4, then concentrated to
dryness. Purification by silica gel column chromatogra-
/
D
/
D
/
D
/
D
/
D
phy (2:1 petroleumꢀEtOAc) gave 22 (420 mg, 77.9% for
/
two steps), which was dissolved in a satd soln of NH3 in
MeOH (20 mL). After a week at rt, the reaction mixture
was concentrated, and the residue was purified by
chromatography on Sephadex LH-20 (MeOH) to afford
Compound 9 (550 mg, 0.351 mmol) and 19 (400 mg,
0.355 mmol) were dried together under high vacuum for
2 h and then dissolved in anhyd CH2Cl2 (10 mL).
TMSOTF (5 mL, 0.044 mmol) was added dropwise at ꢃ
/
23 (140 mg, 86.5%) as foamy solid: [a]D
ꢁ158 (c 1.0,
/
1
20 8C with N2 protection. The reaction mixture was
stirred for 3 h, during which time the temperature was
gradually raised to ambient temperature. Then the
mixture was neutralized with Et3N. Concentration of
the reaction mixture, followed by purification on a silica
H2O); H NMR (D2O, 400 MHz): d 5.31 (d, 1 H, J 3.3
Hz, H-1), 5.28 (s, 1 H, H-1), 5.16 (s, 1 H, H-1), 4.86 (s, 1
H, H-1), 4.56 (d, 1 H, J 7.6 Hz, H-1), 4.43 (d, 1 H, J 7.8
Hz, H-1), 4.10ꢀ
100.7 (2 C-1 for b bonds, JCꢀH
98.9, 98.6 (3 C-1 for mannose a bond, JCꢀH
174.5 Hz), 94.0 (C-1 for glucose a bond, JCꢀH
/
3.45 (m, 36 H); 13C NMR: d 102.3,
163.1ꢀ163.7 Hz), 99.1,
173.0ꢀ
172
ꢄ
/
/
gel column with 1:1 petroleum etherꢀ
eluent gave the product 20 (561 mg, 63.2%) as a syrup:
[a]D ꢁ
478 (c 1.0, CHCl3); 1H NMR (CDCl3, 400 MHz):
d 8.07ꢀ7.26 (m, 60 H, BzꢀH), 6.21 (dd, 1 H, J3,4
J4,5 10.2 Hz, H-4), 6.14 (dd, J2,3 3.2 Hz, J3,4 10.1
Hz, H-3), 6.11 (dd, J2,3 3.2 Hz, J3,4 10.2 Hz, H-3), 6.00
(dd, J2,3 3.2 Hz, J3,4 10.1 Hz, H-3), 5.89ꢀ5.83 (m, 2 H, 2
H-4), 5.79 (d, 1 H, J1,2 3.4 Hz, H-1), 5.78ꢀ5.68 (m, 2 H,
2 H-2), 5.52 (d, 1 H, J1,2 2.2 Hz, H-1), 5.44 (dd, 1 H, J1,2
7.8 Hz, J2,3 9.5 Hz, H-2), 5.30ꢀ5.23 (m, 3 H), 5.13ꢀ5.08
(m, 4 H), 4.93 (d, 1 H, J1,2 7.8 Hz, H-1), 4.85ꢀ4.61 (m, 8
H), 4.53ꢀ4.41 (m, 7 H), 4.32ꢀ4.24 (m, 2 H), 4.20ꢀ3.95
(m, 7 H), 3.85ꢀ3.53 (m, 2 H, H-6), 2.26, 2.23, 2.15, 2.12,
2.11, 1.95 (s, 18 H, 6 CH3CꢁO), 1.30, 1.26 (s, 6 H, 2
CH3); 13C NMR: d 170.8, 170.6, 170.1, 169.7, 169.5,
168.3 (6 CH3CꢁO), 166.2, 166.1, 166.0, 165.8, 165.6,
165.6, 165.4, 165.3, 165.3, 165.3, 165.2, 165.2 (12
COPh), 105.2 (C-1 for glucofuranose a bond, JCꢀH
182.5 Hz), 101.2 (C-1 for b bonds, JCꢀH 163.0 Hz),
98.0, 97.37, 97.2 (3 C-1 for mannose a bond, JCꢀH
172.9ꢀ174.5 Hz), 94.0 (C-1 for glucose a bond, JCꢀH
/EtOAc as the
ꢄ
/
/
ꢄ
/
/
Hz), 82.4, 79.6, 75.4, 74.9, 74.8, 72.7, 72.6, 72.5, 72.4,
72.2, 70.1, 70.0, 69.9, 69.8, 69.6, 69.4, 69.2, 66.3, 66.2,
60.5, 60.3, 60.1 (C-2,-3,-4,-5,-6IꢀVI). Anal. Calcd for
C36H62O31: C, 43.64; H, 6.30. Found: C, 43.24; H, 6.58.
/
/
ꢄ
/
ꢄ
/
/
ESIMS for C36H62O31 (990.87): 989.75 [Mꢃ
1]ꢁ.
/
/
3.17. 2,3,4,6-Tetra-O-benzoyl-a-
(103)-[2,3,4,6-tetra-O-benzoyl-b-
6)]-2,4-di-O-acetyl-a- -glucopyranosyl-(10
O-acetyl-b- -glucopyranosyl-(103)-[2,3,4,6-tetra-O-
benzoyl-a- 6)]-5-O-acetyl-1,2-O-
-mannopyranosyl-(10
isopropylidene-a- -glucofuranose (24)
D
-mannopyranosyl-
-glucopyranosyl-(10
3)-2,4,6-tri-
/
/
/
D
/
/
D
/
/
/
/
D
/
/
D
/
/
D
/
Compound 15 (250 mg, 0.160 mmol) and 19 (180 mg,
0.160 mmol) were dried together under high vacuum for
2 h, then dissolved in anhyd CH2Cl2 (10 mL). TMSOTF
ꢄ
/
ꢄ
/
(5.0 mL, 0.044 mmol) was added dropwise at ꢃ20 8C
/
ꢄ
/
with N2 protection. The reaction mixture was stirred for
3 h, during which time the temperature was gradually
raised to ambient temperature. Then the mixture was
neutralized with Et3N. Concentration of the reaction
mixture, followed by purification on a silica gel column
/
ꢄ
/
172 Hz), 82.3, 78.8, 77.2, 76.2, 75.8, 74.1, 74.0, 74.0,
72.0, 71.8, 71.2, 70.9, 70.4, 70.4, 70.3, 70.2, 69.7, 69.49,
69.2, 68.6, 68.5, 68.1, 66.8, 66.7, 66.3, 63.0, 62.8, 62.8,
62.2, 61.9 (C-2,-3,-4,-5,-6IꢀVI). Anal. Calcd for
with 1:2 petroleum etherꢀEtOAc as the eluent, gave the
/

Z. Wu, F. Kong / Carbohydrate Research 338 (2003) 1727ꢀ
/1735
1735
product 24 (350 mg, 76.3%) as a syrup: [a]D ꢁ
/
188 (c 1.0,
CHCl3); H NMR (CDCl3, 400 MHz): d 8.13ꢀ7.26 (m,
60 H, BzꢀH), 6.27 (dd, 1 H, J3,4 J4,5 10.1 Hz, H-4),
6.11 (dd, 1 H, J3,4 J4,5 10.0 Hz, H-4), 5.87 (dd, 1 H,
by chromatography on Sephadex LH-20 (MeOH) to
1
/
afford 27 (100 mg, 86.3%) as a foamy solid: [a]D
ꢁ308
/
/
ꢄ
/
ꢄ
/
(c 1.0, H2O); 1H NMR (D2O, 400 MHz): d 5.28 (d, 1 H,
J 3.2 Hz, H-1), 5.22 (s, 1 H, H-1), 5.11 (s, 1 H, H-1), 4.86
(d, 1 H, J 7.8 Hz, H-1), 4.56 (d, 1 H, J 7.6 Hz, H-1), 4.50
ꢄ
/
ꢄ
/
J2,3 3.3 Hz, J3,4 10.1 Hz, H-3), 5.81 (d, 1 H, J 3.5 Hz, H-
1), 5.76 (dd, 1 H, J1,2 1.2 Hz, J2,3 2.9 Hz, H-2), 5.66 (dd,
1 H, J2,3 3.3 Hz, J3,4 10.1 Hz, H-3), 5.51 (dd, 1 H, J1,2 1.6
(d, 1 H, J 7.8 Hz, H-1), 4.12ꢀ
d 103.1, 101.2, 100.6 (3 C-1 for b bonds, JCꢀH
164.7 Hz), 98.4, 97.2, 95.2 (3 C-1 for a bond, JCꢀH
172.3ꢀ174.6 Hz), 82.5, 79.1, 78.1, 76.4, 76.3, 75.9, 72.6,
/
3.44 (m, 36 H); 13C NMR:
ꢄ
/
163.0ꢀ
/
Hz, J2,3 3.3 Hz, H-2), 5.27ꢀ
(d, 1 H, J1,2 1.8 Hz, H-1), 5.07 (d, 1 H, J1,2 1.8 Hz, H-1),
4.97 (m, 1 H), 4.97ꢀ4.91 (m, 2 H, 2 H-2), 4.83 (dd, 1 H,
J1,2 3.5 Hz, J2,3 10.7 Hz, H-2), 4.75 (dd, 1 H, J 3.1 Hz, J
9.4 Hz), 4.53ꢀ4.44 (m, 4 H), 4.42ꢀ4.35 (m, 3 H), 4.31ꢀ
4.26 (m, 1 H), 4.25ꢀ4.13 (m, 4 H), 4.03ꢀ3.78 (m, 3 H),
3.76ꢀ3.69 (m, 1 H, H-5), 3.66ꢀ3.58 (m, 1 H, H-5), 2.26,
2.19, 2.14, 2.13, 2.10, 2.09 (s, 18 H, 6 CH3CꢁO) 1.32,
1.26 (s, 6 H, 2 CH3); 13C NMR: d 170.6, 170.6, 169.8,
O, 6 COPh), 166.2,
/5.21 (m, 2 H, H-5, H-2), 5.09
ꢄ
/
/
/
72.3, 72.1, 72.0, 70.5, 70.2, 70.0, 69.9, 68.8, 68.4, 68.38,
66.8, 66.0, 65.7, 62.9 (C-2,-3,-4,-5,-6IꢀVI). Anal. Calcd
for C36H62O31: C, 43.64; H, 6.30. Found: C, 43.36; H,
/
/
/
/
/
6.61. ESIMS for C36H62O31 (990.87): 989.72 [Mꢃ
1]ꢁ.
/
/
/
/
169.7, 169.3, 169.1 (6 C, CH3C ꢁ
/
Acknowledgements
166.1, 166.0, 165.8, 165.6, 165.6, 165.4, 165.4, 165.3,
165.3, 165.3, 165.3 (12 COPh), 105.2 (C-1 for glucofur-
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).
anose a bond, JCꢀH
JCꢀH
163.2 Hz), 99.4 (C-1 for b bonds, JCꢀH
Hz), 98.3, 97.4, 94.0 (3 C-1 for a bond, JCꢀH
ꢄ
/
182.4 Hz), 101.2 (C-1 for b bonds,
163.0
173.0ꢀ
ꢄ
/
ꢄ
/
ꢄ
/
/
174.5 Hz), 83.2, 82.5, 79.1, 78.1, 76.3, 72.5, 72.3, 72.1,
71.9, 70.4, 70.1, 69.9, 68.9, 68.7, 68.4, 68.3, 66.7, 65.9,
65.6, 62.8, 62.2, 61.9, 61.6 (C-2,-3,-4,-5,-6IꢀVI). Anal.
Calcd for C135H126O49: C, 64.03; H, 5.01. Found: C,
64.26; H, 5.35.
References
1. Sasaki, T.; Takasuka, N. Carbohydr. Res. 1976, 47, 99ꢀ
/
105.
2. (a) Molinaro, A.; Lanzetta, R.; Mancino, A.; Evidente, A.;
3.18. a-
D
-Mannopyranosyl-(10
/
3)-[b-
-glucopyranosyl-(103)-b-
-mannopyranosyl-(106)]-b-
D
-glucopyranosyl-
-glucopyranosyl-
-glucopyranose
(10
(10
(27)
/
6)]-a-
3)-[a-
D
/
D
Rosa, M. D.; Ianaro, A. Carbohydr. Res. 2000, 329, 441ꢀ
/
/
D
/
D
448;
(b) Bao, X.; Liu, C.; Fang, J.; Li, X. Carbohydr. Res. 2001,
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3. (a) Norisue, T.; Yanaki, T.; Fujita, H. J. Polym. Sci. 1980,
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(b) Kojima, T.; Tabata, K.; Itoh, W.; Yanaki, T. Agric.
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4. Sasaki, T.; Takasuka, N.; Chihara, G.; Maeda, Y. Y. Gann
1976, 67, 191ꢀ195.
/
134.
A solution of 24 (350 mg, 0.138 mmol) in 90%
CF3COOH (5 mL) was stirred for 2 h at rt until TLC
/
(1:1 petroleum etherꢀEtOAc) indicated that the reaction
/
was complete, then concentrated to dryness. The residue
was dissolved in Py (10 mL) and Ac2O (5 mL) was
added. After stirring the mixture at rt for 12 h, TLC (2:1
/
/
5. Ning, J.; Zhang, W.; Yi, Y.; Yang, G.; Wu, Z.; Yi, J.; Kong,
F. Bioorg. Med. Chem. 2003, in press.
petroleum etherꢀEtOAc) indicated that the reaction was
/
complete. The reaction mixture was extracted with
CH2Cl2 (50 mL) and then washed with dil HCl and
satd aq NaHCO3. The organic phase was dried over
anhyd Na2SO4, then concentrated to dryness. Purifica-
tion by silica gel column chromatography (2:1 petro-
6. Yang, G.; Kong, F. Synlett 2000, 1423ꢀ
7. Schmidt, R. R.; Kinzy, W. Adv. Carbohydr. Chem. Bio-
chem. 1994, 50, 21ꢀ125.
8. (a) Zeng, Y.; Ning, J.; Kong, F. Carbohydr. Res. 2003, 338,
307ꢀ311;
(b) Zeng, Y.; Ning, N.; Kong, F. Tetrahedron Lett. 2002,
43, 3729ꢀ3733;
(c) Zeng, Y.; Ning, J.; Kong, F. Chin. J. Chem. 2002, 20,
1142ꢀ1144.
/1426.
/
/
leum etherꢀEtOAc) gave 26 (300 mg, 84.9% for two
/
steps) as a syrup, which was dissolved in a satd soln of
NH3 in MeOH (15 mL). After a week at rt, the reaction
mixture was concentrated, and the residue was purified
/
/