Synthesis of heptasaccharide and nonasaccharide analogues of the lentinan repeating unit

Article abstract of DOI:10.1016/j.carres.2004.11.005

β-d-Glcp-(1→3)-β-d-Glcp-(1→3)-[β-d-Glcp-(1→6) ]-β-d-Glcp-(1→3)-β-d-Glcp-(1→3)-[β-d-Glcp-(1→6)] -α-d-Glcp-1→OAll β-d-Glcp-(1→3)-{[β-d-Glcp-(1→6)] -β-d-Glcp-(1→3)-β-d-Glcp-(1→3)}₂-[β-d-Glcp- (1→6)]-α-d-Glcp-1→O-acetonyl The allyl glycoside β-d-Gl

Full text of DOI:10.1016/j.carres.2004.11.005

Carbohydrate
RESEARCH
Carbohydrate Research 340 (2005) 39–48
Synthesis of heptasaccharide and nonasaccharide analogues
of the lentinan repeating unit
Guangbin Yang and Fanzuo Kong*
Research Center for Eco-Environmental Sciences, Academia Sinica, PO Box 2871, Beijing 100085, China
Received 25 August 2004; accepted 3 November 2004
Available online 26 November 2004
Abstract—The allyl glycoside b-D-Glcp-(1!3)-b-D-Glcp-(1!3)-[b-D-Glcp-(1!6)]-b-D-Glcp-(1!3)-b-D-Glcp-(1!3)-[b-D-Glcp-
(1!6)]-a-D-Glcp (18) and the acetonyl glycoside of b-D-Glcp-(1!3)-[b-D-Glcp-(1!6)]-b-D-Glcp-(1!3)-b-D-Glcp-(1!3)-[b-D-
Glcp-(1!6)]-b-D-Glcp-(1!3)-b-D-Glcp-(1!3)-[b-D-Glcp-(1!6)]-a-D-Glcp (28) were synthesized as analogues of the lentinan
heptaose repeating unit. 4,6-O-Benzylidenated monosaccharide donor 3 and 4,6-O-benzylidenated tetrasaccharide acceptor 14 were
used to ensure the b-linkage in the synthesis of 18, while 4,6-O-benzylidenated disaccharide acceptor 20, and 4,6-O-benzylidenated
disaccharide donors 21 and 24 were used to ensure the b-linkage in the synthesis of 28.
ꢀ 2004 Elsevier Ltd. All rights reserved.
Keywords: Trichloroacetimidate; b-(1!6)-Branched b-(1!3)-glucan; Synthesis
1. Introduction
antitumor activity.3 However, an interesting result in
our research revealed that a synthetic allyl glycoside
of b-D-Glcp-(1!3)-[b-D-Glcp-(1!6)]-b-D-Glcp-(1!3)-
b-D-Glcp-(1!3)-[b-D-Glcp-(1!6)]-b-D-Glcp-(1!3)-a-D-
Glcp4 at a dose of 5mg/kg effectively inhibited the U14
tumor (58.4%).5 Encouraged by the bioassay results,
we are trying to synthesize more structurally diverse
3,6-branched glucans and investigate structure–activity
relationships. The major structure of lentinan consists
of a glucoheptaose repeating unit as shown in Figure
1, and its synthesis was reported by our group.4
Polysaccharides with antitumor activity separated from
fungi such as Ganoderma lucidum, Schizophyllum com-
mune, and Lentinus edodes have a b-(1!3)-linked gluco-
syl backbone with b-(1!6)-branched glucosyl side
chains.1 Some physicochemical and immunopharmaco-
logical investigations showed that the antitumor activity
of these glucans may be related to the triple-helix struc-
tures of the b-(1!3)-linked backbone chains,2a,b and
some biological aspects of b-glucans have been repor-
ted.2c–e It was also reported that only higher molecu-
lar-weight fractions (MW >16,000) obtained from
partial hydrolysis of lentinan with formic acid showed
Heptaoside analogues with the b-(1!3)-linked penta-
ose backbone and C-6, C-6000 branches, and C-6 disac-
charide branch were also synthesized.6 We present
OH
HO
OH
O
OH
O
HO
HO
O
HO
HO
O
O
HO
OH
HO
HO
O
O
O
HO
O
O
HO
O
HO
HO
O
O
O
HO
HO
HO
HO
HO
n
Figure 1. Structure of lentinan.
*
Corresponding author. Tel.: +86 10 62936613; fax: +86 10 62923563; e-mail: fzkong@mail.rcees.ac.cn
0008-6215/$ - see front matter ꢀ 2004 Elsevier Ltd. All rights reserved.
doi:10.1016/j.carres.2004.11.005

40
G. Yang, F. Kong / Carbohydrate Research 340 (2005) 39–48
herein the syntheses of allyl glucoheptaoside 18 consist-
ing of the b-(1!3)-linked pentaose backbone with b-
(1!6)-linked glucosyl side chains attached at C-6 and
C-600 of the backbone, and acetonyl glucononaoside 28
consisting of a b-(1!3)-linked hexaose backbone with
glucosyl side chains linked at C-6, C-600, and C-60000,
respectively.
ylidene-a-D-glucopyranosyl trichloroacetimidate4 (21),
followed by dechloroacetylation, afforded the tetrasac-
charide acceptor 23. Subsequent coupling of 23 with
the disaccharide donor 246 produced the hexasaccharide
25 with benzylidene groups at the 4,6-, 400,600-, and
40000,60000-positions, respectively. Removal of the benzylid-
ene groups of 25, followed by selective coupling with 9,
and then deacylation, gave the target nonaoside 28.
In summary, with benzylidenated monosaccharide
and disaccharide donors, and benzylidenated oligosac-
charide acceptors, b-(1!3)-linked glucans were readily
obtained, and the formation9 of a-linkages was
restrained.
2. Results and discussion
Scheme 1 shows the synthesis of the glucoheptaoside
18. Allyl 3-O-chloroacetyl-2-O-benzoyl-4,6-O-benzyl-
idene-a-D-glucopyranoside4 (1), allyl 4,6-di-O-acetyl-3-
O-chloroacetyl-2-O-benzoyl-b-D-glucopyranosyl-(1!3)-
2-O-benzoyl-4,6-O-benzylidene-a-D-glucopyranoside4 (4),
and 2,3,4,6-tetra-O-benzoyl-a-D-glucopyranosyltrichlo-
roacetimidate7 (9) were used as the key synthons.
Deallylation of 1 with PdCl2 in acetic acid containing so-
dium acetate gave 2, and the benzylidene group was not
affected under the mild conditions. Subsequent trichlo-
roacetimidate formation with trichloroacetonitrile in
the presence of DBU afforded the glycosyl donor 3.
Meanwhile, removal of the benzylidene group of 4 in
glycol–acetonitrile with toluenesulfonic acid furnished
the diol acceptor 5, while subsequent acetylation of 5,
deallylation, and trichloroacetimidate formation pro-
duced the disaccharide donor 8. Condensation of the
diol 5 with 9 selectively yielded (1!6)-linked trisaccha-
ride 10, then acetylation and dechloroacetylation with
thiourea gave the trisaccharide acceptor 12. Conse-
quently, coupling of 12 with the donor 3, followed by
dechloroacetylation, furnished the tetrasaccharide
acceptor 14, and subsequent coupling of 14 with the
disaccharide donor 8 gave the hexasaccharide 15.
Debenzylidenation of 15 followed by selective coupling
with 9 afforded the heptasaccharide 17. Finally, depro-
tection produced the target heptaoside 18.
Scheme 2 shows the synthesis of glucononaoside 28.
First, acetonyl 4,6-di-O-acetyl-3-O-chloroacetyl-2-O-
benzoyl-b-D-glucopyranosyl-(1!3)-2-O-benzoyl-4,6-O-
benzylidene-a-D-glucopyranoside (19) was obtained by
oxidation of the corresponding allyl glycoside of disac-
charide 4 with PdCl2. Actually, our original goal was
to remove the allyl group of 4 to obtain the correspond-
ing hemiacetal. However, it was found that treatment of
4 in tetrahydrofuran, which was not purged with nitro-
gen to remove the air, with PdCl2 gave 19 and the hemi-
acetal in almost equal amount, and the two products
were easily separated. Similar oxidation of the allyl group
to the acetonyl group was reported many years ago.8
The disaccharide acceptor 20 was readily obtained by
dechloroacetylation of 19 with thiourea. Condensation
of 20 with 4,6-di-O-acetyl-3-O-chloroacetyl-2-O-ben-
zoyl-b-D-glucopyranosyl-(1!3)-2-O-benzoyl-4,6-O-benz-
Preliminary bioassays for 18 and 28 revealed that 18
had activity similar to the lentinan heptaoside,4,5 while
28 showed even better activity.
3. Experimental
3.1. General methods
Melting points were determined with a ꢀMel-Tempꢁ
apparatus. Optical rotations were determined with a
Perkin–Elmer model 241-MC automatic polarimeter
for solutions in a 1dm, jacketed cell. 1H NMR and
13C NMR spectra were recorded with Varian XL-400
spectrometers, for solutions in CDCl3 or in D2O as indi-
cated, and individual resonances could not be identified
with the specific sugar residues using 1D techniques.
Chemical shifts are expressed in ppm downfield from
the Me4Si absorption. Mass spectra were recorded with
a VG PLATFORM mass spectrometer operating in the
ESI mode. Thin-layer chromatography (TLC) was per-
formed on silica gel HF with detection by charring with
30% (v/v) sulfuric acid in methanol or by UV detection.
Column chromatography was conducted by elution of a
column (8 · 100mm, 16 · 240mm, 18 · 300mm,
35 · 400mm) of silica gel (100–200mesh) with EtOAc–
petroleum ether (bp 60–90ꢁC) as the eluent. Analytical
LC was performed with a Gilson HPLC consisting
of a pump (model 306), stainless steel column packed
with silica gel (Spherisorb SiO2, 10 · 300mm or
4.6 · 250mm), differential refractometer (132-RI Detec-
tor), UV/vis detector (model 118). EtOAc–petroleum
ether (bp 60–90ꢁC) was used as the eluent at a flow rate
of 1–4mL/min. Solutions were concentrated at a tem-
perature <60ꢁC under diminished pressure.
3.2. General procedure for trichloroacetimidate formation
To a solution of the hemiacetal (0.4–2.2mmol) in dry
CH2Cl2 (10–25mL) were added CCl3CN (3equiv) and
DBU (10–55lL). The mixture was stirred at rt for 2h,
at the end of which time TLC (3:1 petroleum ether–

G. Yang, F. Kong / Carbohydrate Research 340 (2005) 39–48
Ph
41
Ph
O
O
Ph
O
O
O
O
O
O
O
a
b
OH
CAO
CAO
CAO
BzO
BzO
BzO
OAll
OC(NH)CCl
3
1
2
3
Ph
O
O
AcO
HO
O
O
OAc
O
O
OAc
O
OAc
O
6 R = All
c
HO
d
a
b
AcO
O
O
AcO
AcO
7 R = OH
AcO
O
BzO
OAll
BzO
BzO
OR
CAO
CAO
OAll
CAO
8 R = C(NH)CCl
BzO
BzO
3
BzO
4
5
BzO
BzO
BzO
O
BzO
O
O
BzO
e
BzO
1
10 R = H, R = CA
d
f
BzO
5
+
BzO
1
O
OC(NH)CCl
11 R = Ac, R = CA
3
OAc
O
RO
1
12 R = Ac, R = H
AcO
9
O
BzO
OAll
1
R O
BzO
BzO
BzO
BzO
O
O
e
13 R = CA
14 R = H
12
3
+
BzO
f
O
OAc
O
Ph
O
AcO
O
O
O
AcO
BzO
OAll
O
RO
BzO
BzO
BzO
BzO
BzO
O
O
BzO
AcO
AcO
O
OAc
O
Ph
O
O
O
O
AcO
O
OAc
c
O
BzO
15
e
AcO
AcO
14
8
BzO
OAll
+
O
CA
O
BzO
BzO
BzO
BzO
O
BzO
O
BzO
BzO
O
AcO
AcO
OAc
O
HO
9
e
AcO
O
OAc
O
O
AcO
HO
AcO
BzO
OAll
O
O
CA
O
BzO
BzO
16
BzO
BzO
BzO
BzO
BzO
BzO
O
O
BzO
O
O
BzO
BzO
BzO
O
O
g
AcO
AcO
OAc
O
AcO
O
OAc
O
AcO
O
HO
O
AcO
CA
BzO
OAll
O
BzO
BzO
17
BzO
BzO
OH
O
OH
HO
HO
O
VI
HO
HO
VII
O
I
O
HO
OH
HO
OH
OH
O
HO
HO
O
O
HO
HO
O
HO
HO
O
HO
O
II
III
IV
O
V
O
O
HO
HO
HO
18
HO
OAll
Scheme 1. Reagents and conditions: (a) PdCl2, 75% HOAc (75%)–NaOAc (or MeOH), rt, 80% for 2, 82% for 7; (b) DBU, Cl3CCN, CH2Cl2, rt, 82%
for 3, 87% for 8; (c) C2H4(OH)2, MeCN, TsOH, rt, 91% for 5, 79% for 16; (d) Ac2O, Pyr, (or AcCl, Pyr, CH2Cl2), rt, 98% for 6, 90% for 11; (e)
TMSOTf, CH2Cl2, ꢀ10ꢁC, 4h, 91% for 10, 79% for 13, 75% for 15, 80% for 17; (f) thiourea, 2,4-lutidine, CH2Cl2–MeOH, reflux, overnight, 89% for
12, 71% for 14; (g) satd NH3–MeOH, rt, 48h, 98%.
EtOAc) indicated that the reaction was complete. The
mixture was concentrated, and the residue so obtained
was subjected to column chromatography with 3:1 petro-
leum ether–EtOAc as the eluent to give the product.

42
G. Yang, F. Kong / Carbohydrate Research 340 (2005) 39–48
Ph
Ph
O
O
Ph
OAc
O
O
OAc
O
OAc
O
O
O
O
O
O
O
O
O
a
b
AcO
CAO
AcO
HO
AcO
CAO
O
BzO
BzO
BzO
BzO
BzO
OAll
BzO
OCH2COMe
OCH2COMe
20
4
19
Ph
O
OAc
O
Ph
O
O
Ph
O
O
O
O
O
OAc
O
OAc
O
AcO
O
O
O
O
AcO
RO
c
AcO
O
BzO
BzO
20
+
OCH2COMe
CAO
BzO
BzO
BzO
BzO
OC(NH)CCl3
21
22 R = CA
23 R = H
b
Ph
O
OBz
O
O
O
BzO
BzO
O
BzO
BzO
OC(NH)CCl3
24
Ph
O
O
OAc
Ph
O
O
O
Ph
O
OAc
O
O
O
OBz
AcO
O
O
c
O
O
O
AcO
O
O
O
BzO
BzO
O
BzO
O
OCH2COMe
BzO
BzO
BzO
BzO
BzO
25
HO
HO
OAc
O
HO
OAc
O
HO
9
c
OBz
AcO
O
O
HO
O
HO
O
O
AcO
O
O
d
BzO
BzO
BzO
BzO
OCH2COMe
BzO
BzO
BzO
BzO
26
OBz
O
BzO
OBz
O
BzO
BzO
OBz
O
BzO
BzO
O
O
BzO
BzO
O
BzO
OAc
e
OAc
BzO
O
HO
O
O
OBz
AcO
O
O
HO
O
O
HO
O
AcO
O
O
BzO
O
BzO
BzO
OCH2COMe
BzO
BzO
BzO
BzO
BzO
27
OH
VII
O
OH
VIII
HO
HO
OH
IX
O
O
HO
HO
O
O
HO
HO
HO
O
HO
OH
HO
O
HO
OH
IV
HO
O
O
O
OH
VI
HO
O
I
HO
O
O
O
HO
O
II
HO
O
III
HO
HO
O
V
OCH2COMe
HO
HO
HO
HO
HO
28
Scheme 2. Reagents and conditions: (a) PdCl2, THF, HOAc (75%)–NaOAc, rt, overnight, 36%; (b) thiourea, 2,4-lutidine, CH2Cl2–MeOH, reflux,
overnight, 87% for 20, 81% for 23,; (c) TMSOTf, CH2Cl2, ꢀ10ꢁC, 2–4h; 71% for 22, 50% for 25, 55% for 27; (d) TsOH, CH2(OH)2, MeCN, rt,
overnight, 69%; (e) satd NH3–MeOH, rt, 48h, 98%.
3.3. General procedure for the coupling reaction
3.4. 2-O-Benzoyl-4,6-O-benzylidene-3-O-chloroacetyl-a-
D-glucopyranose (2)
To a solution of almost equivalent amounts of glycosyl
acceptor and donor in CH2Cl2 (15–25mL) was added
˚
4A molecular sieves (0.5–0.8g). The mixture was stirred
To a solution of NaOAc (980mg, 11.95mmol) and
PdCl2 (1.06g, 5.98mmol) in HOAc (75%, 5mL) was
added compound 1 (1.5g, 3.07mmol). The mixture
was stirred at rt overnight under the N2 protection, at
the end of which time TLC (2:1 petroleum ether–
EtOAc) indicated that the reaction was complete. The
mixture was filtered, and the filter cake was washed with
CH2Cl2. The organic phase was washed with satd aq
NaHCO3 and water, then dried and concentrated. Puri-
fication by column chromatography with 2:1 petroleum
ether–EtOAc as the eluent afforded compound 2 (1.1g,
and cooled to ꢀ10ꢁC under N2 protection, and
TMSOTf (5–10%equiv) was added. Stirring was contin-
ued at low temperature (ꢀ10ꢁC) for 4h, at the end of
which time TLC (2:1 petroleum ether–EtOAc) indicated
that the reaction was complete. Et3N was added to stop
the reaction, the mixture was filtered, and the filter cake
was washed with CH2Cl2. The combined filtrate and
washings were washed with satd aq NaHCO3 and water,
then dried and concentrated. Purification by column
chromatography with 3:1 petroleum ether–EtOAc as
the eluent afforded the product.
20
1
80%) as a syrup: ½aꢁ +90.0 (c 0.7, CHCl3); H NMR:
D
d 8.04–7.36 (m, 10H, Bz–H, Ph–H), 5.90 (dd, 1H, J2,3

G. Yang, F. Kong / Carbohydrate Research 340 (2005) 39–48
43
9.8Hz, J3,4 9.8Hz, H-3), 5.65 (d, 1H, J1,2 3.7Hz, H-1),
3.7. Allyl 4,6-di-O-acetyl-2-O-benzoyl-3-O-chloroacetyl-
b-D-glucopyranosyl-(1!3)-4,6-di-O-acetyl-2-O-benzoyl-
5.55 (s, 1H, PhCH), 5.12 (dd, 1H, J1,2 3.7Hz, J2,3
9.8Hz, H-2), 4.33 (dd, 1H, J5,6a 4.9Hz, J6a,6b 10.1Hz,
H-6a), 4.33–4.23 (m, 1H, H-5), 4.02, 3.97 (ABq, 2H, J
14.7Hz, ClCH2CO), 3.81 (dd, 1H, J5,6b 10.1Hz, J6a,6b
10.1Hz, H-6b), 3.80 (dd, 1H, J3,4 9.8Hz, J4,5 9.8Hz,
H-4). Anal. Calcd for C22H21ClO8: C, 58.87; H, 4.72.
Found: C, 58.76; H, 4.64.
a-D-glucopyranoside (6)
To a solution of compound 5 (600mg, 0.80mmol) in
CH2Cl2 (10mL) was added pyridine (4mL) and Ac2O
(3mL). The mixture was stirred at rt for 4h, at which
time TLC (2:1 petroleum ether–EtOAc) indicated that
the reaction was complete. Concentration of the mixture
in vacuo and purification the residue by column chro-
matography with 3:1 petroleum ether–EtOAc as the elu-
ent afforded compound 6 (654mg, 98%) as a syrup:
3.5. 2-O-Benzoyl-4,6-O-benzylidene-3-O-chloroacetyl-a-
D-glucopyranosyl trichloroacetimidate (3)
20
D
1
½aꢁ +55.9 (c 0.9, CHCl3); H NMR: d 7.89–7.07 (m,
Compound 3 was obtained as a syrup (1.09g, 82.5%)
from compound
10H, 2Bz–H), 5.80–5.70 (m, 1H, CH2@CH–CH2–),
5.32 (dd, 1H, J3,4 = J2,3 = 9.5Hz, H-30), 5.23–5.17 (m,
3H, CH2@CH–CH2–, H-20), 5.15 (d, 1H, J1,2 3.7Hz,
H-1), 5.12 (dd, 1H, J3,4 = J4,5 = 9.8Hz, H-40), 5.09 (dd,
1H, J3,4 = J4,5 = 9.5Hz, H-4), 4.91 (d, 1H, J1,2 7.7Hz,
H-10), 4.88 (dd, 1H, J1,2 3.7Hz, J2,3 9.8Hz, H-2), 4.47
(dd, 1H, J5,6a = 4.2Hz, J6a,6b 12.4Hz, H-6a), 4.36 (dd,
1H, J2,3 = J3,4 = 9.8Hz, H-3), 4.21 (dd, 1H, J5,6b
4.5Hz, J6a,6b 12.4Hz, H-6b), 4.15–3.82 (m, 6H,
CH2@CH–CH2–, H-5, 50, 60), 3.84, 3.78 (ABq, 2H, J
14.9Hz, ClCH2CO), 2.11, 2.11, 2.07, 2.04 (4s, 12H,
4CH3CO). Anal. Calcd for C39H43ClO18: C, 56.08; H,
5.19. Found: C, 56.16; H, 5.32.
2
(1.0g, 2.23mmol), CCl3CN
(0.66mL, 6.6mmol), and DBU (55lL) according to
the general procedure for trichloroacetimidate forma-
20
D
1
tion: ½aꢁ +78.0 (c 1.2, CHCl3); H NMR: d 8.60 (s,
1H, NH), 8.01–7.37 (m, 10H, Bz–H, Ph–H), 6.71 (d,
1H, J1,2 3.8Hz, H-1), 5.94 (dd, 1H, J2,3 = J3,4 = 9.8Hz,
H-3), 5.59 (s, 1H, PhCH), 5.40 (dd, 1H, J1,2 3.8Hz,
J2,3 9.8Hz, H-2), 4.41 (dd, 1H, J5,6a 4.9Hz, J6a,6b
10.4Hz, H-6a), 4.25–4.18 (m, 1H, H-5), 4.03, 4.00
(ABq, 2H, J 14.7Hz, ClCH2CO), 3.93 (dd, 1H,
J3,4 = J4,5 = 9.8Hz, H-4), 3.85 (dd, 1H, J5,6 10.4Hz,
J6a,6b 10.4Hz, H-6). Anal. Calcd for C24H21Cl4NO8:
C, 48.59; H, 3.57. Found: C, 48.76; H, 3.62.
3.6. Allyl 4,6-di-O-acetyl-2-O-benzoyl-3-O-chloroacetyl-
b-D-glucopyranosyl-(1!3)-2-O-benzoyl-a-D-glucopyran-
oside (5)
3.8. 4,6-Di-O-acetyl-2-O-benzoyl-3-O-chloroacetyl-b-D-
glucopyranosyl-(1!3)-4,6-di-O-acetyl-2-O-benzoyl-a-D-
glucopyranose (7)
To a solution of compounds 4 (2g, 2.38mmol) and eth-
ylene glycol (1.0mL, 17.97mmol) in MeCN (20mL) was
added p-toluenesulfonic acidÆH2O (50mg). The mixture
was stirred at rt overnight. TLC (2:1 petroleum ether–
EtOAc) indicated that the reaction was complete. The
mixture was neutralized with Et3N, concentrated and
extracted with CH2Cl2, and the organic phase was
washed with water, then dried and concentrated. Purifi-
cation by column chromatography with 1:1 petroleum
To a solution of compound 6 (550mg, 0.66mmol) in
MeOH (10mL) was added PdCl2 (20mg, 0.11mmol),
and the mixture was stirred at rt for 8h, at the end of
which time TLC (2:1 petroleum ether–EtOAc) indicated
that the reaction was complete. The mixture was filtered,
the filter cake was washed with CH2Cl2, and the com-
bined filtrate and washings was concentrated. Purifica-
tion by column chromatography with 2:1 petroleum
ether–EtOAc as the eluent afforded compound 7
20
ether–EtOAc as the eluent afforded compound
(430mg, 82%) as a syrup: ½aꢁ +30.8 (c 0.7, CHCl3);
D
20
D
1H NMR: d 7.90–7.08 (m, 10H, 2Bz–H), 5.54 (br
s, 1H, H-1), 5.33 (dd, 1H, J3,4 = J2,3 = 9.5Hz, H-30),
5.22 (dd, 1H, J1,2 7.8Hz, J2,3 9.5Hz, H-20), 5.17
(dd, 1H, J3,4 = J4,5 = 9.6Hz, H-40), 5.09 (dd, 1H,
J3,4 = J4,5 = 9.5Hz, H-4), 4.93 (d, 1H, J1,2 7.8Hz, H-
10), 4.88 (dd, 1H, J1,2 3.6Hz, J2,3 9.6Hz, H-2), 4.47
(dd, 1H, J5,6a 4.2Hz, J6a,6b 12.5Hz, H-6a), 4.41 (dd,
1H, J2,3 = J3,4 = 9.6Hz, H-3), 4.25–4.20 (m, 1H, H-50),
4.17 (d, 2H, J5,6 3.3Hz, H-60), 4.13 (dd, 1H, J5,6b
2.1Hz, J6a,6b 12.5Hz, H-6b), 3.87–3.84 (m, 1H, H-5),
3.85, 3.78 (ABq, 2H, J 14.9Hz, ClCH2CO), 2.11, 2.11,
2.08, 2.04 (4s, 12H, 4CH3CO). Anal. Calcd for
C36H39ClO18: C, 54.38; H, 4.94. Found: C, 54.22; H,
4.78.
5 (1.63g, 91%) as a syrup: ½aꢁ +87.5 (c 1.0, CHCl3);
1H NMR: d 7.71–7.01 (m, 10H, 2Bz–H), 5.78–5.68
(m, 1H, CH2@CH–CH2–), 5.44 (dd, 1H, J3,4
=
J2,3 = 9.6Hz, H-30), 5.31 (dd, 1H, J1,2 7.9Hz, J2,3
9.6Hz, H-20), 5.20–5.05 (m, 2H, CH2@CH–CH2–),
5.17 (dd, 1H, J3,4 = J4,5 = 9.6Hz, H-40), 5.10 (d, 1H,
J1,2 3.8Hz, H-1), 4.90 (dd, 1H, J1,2 3.8Hz, J2,3 9.8Hz,
H-2), 4.88 (d, 1H, J1,2 7.9Hz, H-10), 4.28 (d, 2H, J5,6
4.0Hz, H-60), 4.16–3.76 (m, 6H, CH2@CH–CH2–, H-5,
50, 6), 3.85, 3.78 (ABq, 2H, J 14.8Hz, ClCH2CO), 3.94
(dd, 1H, J2,3 = J3,4 = 9.8Hz, H-3), 3.71 (dd, 1H,
J3,4 = J4,5 = 9.8Hz, H-4), 2.13, 2.05 (2s, 6H, 2CH3CO).
Anal. Calcd for C35H39ClO16: C, 55.96; H, 5.23. Found:
C, 55.84; H, 5.12.

44
G. Yang, F. Kong / Carbohydrate Research 340 (2005) 39–48
3.9. 4,6-Di-O-acetyl-2-O-benzoyl-3-O-chloroacetyl-b-D-
glucopyranosyl-(1!3)-4,6-di-O-acetyl-2-O-benzoyl-a-D-
glucopyranosyl trichloroacetimidate (8)
ꢀ10ꢁC, was added a solution of AcCl (0.2mL,
2.80mmol) in CH2Cl2 (5mL), and the mixture was stir-
red for 4h at rt. TLC (3:1 petroleum ether–EtOAc) indi-
cated that the reaction was complete. The mixture was
diluted with CH2Cl2 and poured into ice water, then
the organic phase was separated, successively washed
with N HCl, satd aq NaHCO3, and water, dried, and
concentrated. Purification by column chromatography
with 3:1 petroleum ether–EtOAc as the eluent afforded
compound 11 (650mg, 90%) as an amorphous solid:
Compound 8 was obtained as a syrup (340mg, 87%)
from compound
7 (330mg, 0.42mmol), CCl3CN
(0.12mL, 1.22mmol), and DBU (10lL) according to
the general procedure for trichloroacetimidate forma-
20
D
1
tion: ½aꢁ +54.3 (c 1.5, CHCl3); H NMR: d 8.54 (s,
1H, NH), 7.80–7.12 (m, 10H, 2Bz–H), 6.55 (d, 1H, J1,2
3.6Hz, H-1), 5.31 (dd, 1H, J3,4 = J2,3 = 9.4Hz, H-30),
5.24–5.12 (m, 4H, H-2, 20, 4, 40), 4.87 (d, 1H, J1,2
7.8Hz, H-10), 4.44 (dd, 1H, J5,6a 4.5Hz, J6a,6b 12.5Hz,
H-6a), 4.38 (dd, 1H, J2,3 = J3,4 = 9.7Hz, H-3), 4.23–
3.85 (m, 5H, H-5, 50, 6b, 60), 3.82, 3.76 (ABq, 2H, J
14.8Hz, ClCH2CO), 2.11, 2.08, 2.07, 2.02 (4s, 12H,
4CH3CO). Anal. Calcd for C38H39Cl4NO18: C, 48.58;
H, 4.18. Found: C, 48.26; H, 4.25.
20
1
½aꢁ +31.9 (c 0.5, CHCl3); H NMR: d 8.04–7.07 (m,
D
30H, 6Bz–H), 5.90 (dd, 1H, J2,3 = J3,4 = 9.7Hz, H-300),
5.67 (dd, 1H, J3,4 = J4,5 = 9.7Hz, H-400), 5.53 (dd, 1H,
J1,2 8.0Hz, J2,3 9.7Hz, H-200), 5.52–5.42 (m, 1H,
0
0
CH2@CH–CH2–), 5.27 (dd, 1H, J3,4 = J2 ,3 = 9.4Hz,
H-30), 5.19 (dd, 1H, J1,2 7.8Hz, J2,3 9.4Hz, H-20), 5.14
(dd, 1H, J3,4 = J4,5 = 9.4Hz, H-40), 5.03–4.93 (m, 2H,
CH2@CH–CH2–), 4.90 (d, 1H, J1,2 7.8Hz, H-10), 4.84
(d, 1H, J1,2 8.0Hz, H-100), 4.80 (d, 1H, J1,2 3.7Hz, H-
1), 4.79 (dd, 1H, J3,4 = J4,5 = 9.8Hz, H-4), 4.70 (dd,
1H, J1,2 3.7Hz, J2.3 9.5Hz, H-2), 4.63 (dd, 1H, J5,6a
2.8Hz, J6a,6b = 12.2Hz, H-6a00), 4.48 (dd, 1H, J5,6b
4.5Hz, J6a,6b 12.2Hz, H-6b00), 4.46–3.37 (m, 9H,
CH2@CH–CH2–, H-5, 50, 500, 6, 60), 4.27 (dd, 1H,
J2,3 = J3,4 = 9.8Hz, H-3), 3.83, 3.76 (ABq, 2H, J
14.8Hz, ClCH2CO), 2.08, 2.02, 2.00 (3s, 9H, 3CH3CO).
Anal. Calcd for C71H67ClO26: C, 62.16; H, 4.92. Found:
C, 61.86; H, 5.02.
3.10. Allyl 4,6-di-O-acetyl-2-O-benzoyl-3-O-chloroacetyl-
b-D-glucopyranosyl-(1!3)-[2,3,4,6-tetra-O-benzoyl-b-D-
glucopyranosyl-(1!6)]-2-O-benzoyl-a-D-glucopyranoside
(10)
Compound 10 (806mg, 91%) was obtained as an amor-
phous solid from compounds 5 (500mg, 0.67mmol) and
9 (600mg, 0.80mmol) according to the general proce-
20
dure for the coupling reaction: ½aꢁ +49.9 (c 1.2,
D
1
CHCl3); H NMR: d 8.04–6.98 (m, 30H, 6Bz–H), 5.93
(dd, 1H, J2,3 = J3,4 = 9.6Hz, H-300), 5.70 (dd, 1H,
J3,4 = J4,5 = 9.6Hz, H-400), 5.57 (dd, 1H, J1,2 7.9Hz,
J2,3 9.6Hz, H-200), 5.56–5.46 (m, 1H, CH2@CH–CH2–),
5.39 (dd, 1H, J3,4 = J2,3 = 9.6Hz, H-30), 5.25 (dd, 1H,
J1,2 8.0Hz, J2,3 9.6Hz, H-20), 5.13 (dd, 1H,
3.12. Allyl 4,6-di-O-acetyl-2-O-benzoyl-b-D-glucopyrano-
syl-(1!3)-[2,3,4,6-tetra-O-benzoyl-b-D-glucopyranosyl-
(1!6)]-4-O-acetyl-2-O-benzoyl-a-D-glucopyranoside (12)
Compound 10 (550mg, 0.40mmol) was dissolved in
mixed solvents of CH2Cl2 (4mL) and MeOH (6mL).
To the solution were added thiourea (152mg,
2.00mmol) and 2,4-lutidine (45lL, 0.41mmol), and
the reaction mixture was boiled under reflux for 16h,
at the end of which time TLC (2:1 petroleum ether–
EtOAc) indicated that the reaction was complete. The
mixture was concentrated and extracted with CH2Cl2,
the organic phase was successively washed with N
HCl, satd aq NaHCO3, and water, dried, and concen-
trated. Purification by column chromatography with
J3,4 = J4,5 = 9.6Hz,
H-40),
5.06–4.93
(m,
2H,
CH2@CH–CH2–), 4.97 (d, 1H, J1,2 8.0Hz, H-10), 4.84
(d, 1H, J1,2 3.8Hz, H-1), 4.78 (d, 1H, J1,2 7.9Hz, H-
100), 4.64 (dd, 1H, J5,6a 2.8Hz, J6a,6b 12.2Hz, H-6a00),
4.63 (dd, 1H, J1,2 3.8Hz, J2,3 9.5Hz, H-2), 4.51 (dd,
1H, J5,6b 4.6Hz, J6a,6b 12.2Hz, H-6b00), 4.31 (bd, 1H,
J6a,6b 11.6Hz, H-6a), 4.22 (d, 2H, J5,6 4.0Hz, H-60),
4.22–3.72 (m, 5H, CH2@CH–CH2–, H-5, 50, 500), 3.99
(dd, 1H, J2,3 = J3,4 = 9.5Hz, H-3), 3.85, 3.78 (ABq,
2H, J 14.8Hz, ClCH2CO), 3.54 (dd, 1H, J5,6b 4.7Hz,
J6a,6b 11.6Hz, H-6b), 3.44 (dd, 1H, J3,4 = J4,5 = 9.5Hz,
H-4), 2.11, 2.06 (2s, 6H, 2CH3CO). Anal. Calcd for
C69H65ClO25: C, 62.32; H, 4.93. Found: C, 62.16; H,
4.80.
2:1 petroleum ether–EtOAc as the eluent afforded 12
20
D
(460mg, 89%) as an amorphous solid: ½aꢁ +41.9 (c
1
1.5, CHCl3); H NMR: d 8.03–7.16 (m, 30H, 6Bz–H),
5.90 (dd, 1H, J2,3 = J3,4 = 9.7Hz, H-300), 5.67 (dd, 1H,
J3,4 = J4,5 = 9.7Hz, H-400), 5.53 (dd, 1H, J1,2 8.0Hz,
J2,3 9.7Hz, H-200), 5.55–5.45 (m, 1H, CH2@CH–CH2–),
5.06–4.98 (m, 4H, CH2@CH–CH2–, H-20, 40), 4.92 (d,
1H, J1,2 7.8Hz, H-10), 4.87 (d, 1H, J1,2 3.7Hz, H-1),
4.83 (d, 1H, J1,2 8.0Hz, H-100), 4.77 (dd, 1H,
J3,4 = J4,5 = 9.6Hz, H-4), 4.74 (dd, 1H, J1,2 3.7Hz, J2.3
9.6Hz, H-2), 4.64 (dd, 1H, J5,6a 2.9Hz, J6a,6b 12.3Hz,
H-6a00), 4.48 (dd, 1H, J5,6b 4.7Hz, J6a,6b 12.3Hz,
3.11. Allyl 4,6-di-O-acetyl-2-O-benzoyl-3-O-chloroacetyl-
b-D-glucopyranosyl-(1!3)-[2,3,4,6-tetra-O-benzoyl-b-D-
glucopyranosyl-(1!6)]-4-O-acetyl-2-O-benzoyl-a-D-
glucopyranoside (11)
To a solution of compound 10 (700mg, 0.53mmol) in
CH2Cl2 (10mL) containing pyridine (0.4mL) was cooled

G. Yang, F. Kong / Carbohydrate Research 340 (2005) 39–48
45
H-6b00), 4.45–3.42 (m, 9H, CH2@CH–CH2–, H-5, 50, 500,
6, 60), 4.30 (dd, 1H, J2,3 = J3,4 = 9.6Hz, H-3), 3.70 (dd,
1H, J2,3 = J3,4 = 9.4Hz, H-30), 2.09, 2.09, 2.01, 2.00
(3s, 9H, 3CH3CO). Anal. Calcd for C69H66O25: C,
63.98; H, 5.14. Found: C, 63.76; H, 5.12.
(s, 1H, PhCH), 5.51 (dd, 1H, J1,2 8.0Hz, J2,3 9.7Hz,
H-2IV), 5.50–5.40 (m, 1H, CH2@CH–CH2–), 5.10 (dd,
1H, J3,4 = J4,5 = 9.4Hz, H-4II), 5.04–4.87 (m, 4H,
CH2@CH–CH2–, H-1I, 2II), 4.88 (d, 1H, J1,2 8.0Hz,
H-1IV), 4.73–4.55 (m, 6H, H-1II,III, 2I,III, 4, 6IV), 4.50–
3.33 (m, 17H, CH2@CH–CH2–, H-3I–III, 4III, 5I–IV
,
3.13. Allyl 2-O-benzoyl-4,6-O-benzylidene-3-O-chloro-
acetyl-b-D-glucopyranosyl-(1!3)-4,6-di-O-acetyl-2-O-
benzoyl-b-D-glucopyranosyl-(1!3)-[2,3,4,6-tetra-O-benz-
oyl-b-D-glucopyranosyl-(1!6)]-4-O-acetyl-2-O-benzoyl-
a-D-glucopyranoside (13)
60IV, 6I–III), 2.07, 2.01, 1.94 (3s, 12H, 3CH3CO). Anal.
Calcd for C89H84O31: C, 64.80; H, 5.13. Found: C,
64.76; H, 5.02.
3.15. Allyl 4,6-di-O-acetyl-2-O-benzoyl-3-O-chloroacetyl-
b-D-glucopyranosyl-(1!3)-4,6-di-O-acetyl-2-O-benzoyl-
b-D-glucopyranosyl-(1!3)-2-O-benzoyl-4,6-O-benzylid-
ene-b-D-glucopyranosyl-(1!3)-4,6-di-O-acetyl-2-O-benz-
oyl-b-D-glucopyranosyl-(1!3)-[2,3,4,6-tetra-O-benzoyl-
b-D-glucopyranosyl-(1!6)]-4-O-acetyl-2-O-benzoyl-a-D-
glucopyranoside (15)
Compound 13 (380mg, 79%) was obtained as an amor-
phous solid from compounds 12 (360mg, 0.28mmol)
and 3 (200mg, 0.34mmol) according to the general pro-
20
cedure for the coupling reaction: ½aꢁ +13.5 (c 0.5,
D
1
CHCl3); H NMR: d 8.10–7.00 (m, 40H, 7Bz–H, Ph–
H), 5.88 (dd, 1H, J2,3 = J3,4 = 9.6Hz, H-3IV), 5.65 (dd,
1H, J3,4 = J4,5 = 9.6Hz, H-4IV), 5.50 (dd, 1H, J1,2
8.0Hz, J2,3 9.6Hz, H-2IV), 5.47 (s, 1H, PhCH), 5.48–
5.38 (m, 1H, CH2@CH–CH2–), 5.21 (dd, 1H,
J2,3 = J3,4 = 9.2Hz, H-3III), 5.07 (dd, 1H, J1,2 7.8Hz,
J2,3 9.6Hz, H-2II), 5.02 (dd, 1H, J3,4 = J4,5 = 9.6Hz, H-
4II), 5.02 (dd, 1H, J1,2 8.0Hz, J2,3 9.2Hz, H-2III), 4.99–
4.80 (m, 2H, CH2@CH–CH2–), 4.87 (d, 1H, J1,2
8.0Hz, H-1IV), 4.70–4.60 (m, 5H, H-1I–III, 2, 4), 4.56
(dd, 1H, J5,6 3.1Hz, J6,6 12.4Hz, H-6IV), 4.47 (dd, 1H,
Compound 15 (110mg, 75%) was obtained as an amor-
phous solid from compounds 14 (100mg, 0.061mmol)
and 8 (75mg, 0.080mmol) according to the general pro-
cedure for the coupling reaction. However, purification
was carried out with 2:1 petroleum ether–EtOAc as
20
D
the eluent: ½aꢁ +66.0 (c 1.2, CHCl3); 1H NMR: d
8.02–7.05 (m, 50H, 9Bz–H, Ph–H), 5.87 (dd, 1H,
J2,3 = J3,4 = 9.8Hz, H-3VI), 5.65 (dd, 1H, J3,4
=
J4,5 = 9.8Hz, H-4VI), 5.50 (dd, 1H, J1,2 8.0Hz, J2,3
9.8Hz, H-2VI), 5.47–5.37 (m, 3H, CH2@CH–CH2–,
PhCH, H-3V), 5.07–4.78 (m, 13H, CH2@CH–CH2–, H-
J5,6 4.7Hz, J6,6 12.4Hz, H-60IV), 4.38 (dd, 1H, J5,6
0
4.9Hz, J6,6 10.2Hz, H-6III), 4.33 (dd, 1H, J5,6 4.2Hz,
J6,6 12.4Hz, H-6II), 4.20–3.31 (m, 13H, CH2@CH–
1I,VI, 2I–V, 4I,II,IV,V), 4.68–3.18 (m, 29H, H-1II–V, 3I–IV
,
0
CH2–, H-3I,II, 4III, 5I–V, 6I, 60I,II,III), 3.83, 3.76 (ABq,
2H, J 14.8Hz, ClCH2CO), 2.08, 2.02, 1.94 (3s, 12H,
3CH3CO). Anal. Calcd for C91H85ClO32: C, 63.32; H,
4.96. Found: C, 63.26; H, 5.00.
4III, 5I–VI, 6I–VI), 3.77, 3.71 (ABq, 2H, J 14.8Hz,
ClCH2CO), 2.05, 2.01, 1.96, 1.91, 1.91, 1.91, 1.91 (7s,
21H, 7CH3CO). 13C NMR (100MHz, CDCl3): d
170.8, 170.7, 169.2, 169.1, 168.4, 168.2, 168.1 (7C,
7CH3CO–), 166.2, 166.1, 165.9, 165.7, 165.3, 165.2,
165.0, 164.9, 164.7 (9C, 9COPh), 134.3 (1C,
CH2@CH–CH2), 118.1 (1 C, CH2@CH–CH2), 101.2
(–CHPh), 101.0, 100.8, 100.7, 100.6, 99.9 (5C, bC-1),
95.8 (1C, aC-1). Anal. Calcd for C125H121ClO48: C,
61.86; H, 5.03. Found: C, 61.95; H, 5.08.
3.14. Allyl 2-O-benzoyl-4,6-O-benzylidene-b-D-glucopyran-
osyl-(1!3)-4,6-di-O-acetyl-2-O-benzoyl-b-D-glucopyran-
osyl-(1!3)-[2,3,4,6-tetra-O-benzoyl-b-D-glucopyranosyl-
(1!6)]-4-O-acetyl-2-O-benzoyl-a-D-glucopyranoside
(14)
Compound 13 (280mg, 0.16mmol) was dissolved in
mixed solvents of CH2Cl2 (4mL) and MeOH (6mL).
To the solution were added thiourea (62mg, 0.82mmol)
and 2,4-lutidine (18lL, 0.16mmol), and the reaction
mixture was boiled under reflux for 16h, at the end of
which time TLC (2:1 petroleum ether–EtOAc) indicated
that the reaction was complete. The mixture was con-
centrated and extracted with CH2Cl2, the organic phase
was washed with N HCl, satd aq NaHCO3, and water,
dried, and concentrated. Purification by column chro-
matography with 2:1 petroleum ether–EtOAc as the elu-
ent afforded 14 (190mg, 71%) as an amorphous solid:
3.16. Allyl 4,6-di-O-acetyl-2-O-benzoyl-3-O-chloroacetyl-
b-D-glucopyranosyl-(1!3)-4,6-di-O-acetyl-2-O-benzoyl-
b-D-glucopyranosyl-(1!3)-2-O-benzoyl-b-D-glucopyrano-
syl-(1!3)-4,6-di-O-acetyl-2-O-benzoyl-b-D-glucopyrano-
syl-(1!3)-[2,3,4,6-tetra-O-benzoyl-b-D-glucopyranosyl-
(1!6)]-4-O-acetyl-2-O-benzoyl-a-D-glucopyranoside (16)
To a solution of compounds 15 (70mg, 0.029mmol) and
ethylene glycol (0.1mL, 1.80mmol) in MeCN (5mL)
was added p-toluenesulfonic acidÆH2O (10mg). The
mixture was stirred at rt overnight, at the end of which
time TLC (1:1 petroleum ether–EtOAc) indicated that
the reaction was complete. The mixture was made neu-
tral with Et3N, concentrated and extracted with CH2Cl2
and the organic phase was washed with water, then
20
1
½aꢁ +14.7 (c 1.2, CHCl3); H NMR: d 8.02–7.30 (m,
D
40H, 7Bz–H, Ph–H), 5.88 (dd, 1H, J2,3 = J3,4 = 9.7Hz,
H-3IV), 5.66 (dd, 1H, J3,4 = J4,5 = 9.6Hz, H-4IV), 5.51

46
G. Yang, F. Kong / Carbohydrate Research 340 (2005) 39–48
dried and concentrated. Purification by column chroma-
tography with 1:1 petroleum ether–EtOAc as the eluent
afforded compound 16 (53mg, 79%) as an amorphous
CH2@CH–CH2–), 4.96 (d, 1H, J1,2 3.6Hz, H-1I), 4.84,
4.81, 4.75, 4.74 (4d, 4H, J1,2 8.0Hz, H-1), 4.51, 4.48
(2d, 2H, J1,2 8.0Hz, H-1), 4.28–3.28 (m, 44H,
CH2@CH–CH2–, H-2I–VII, 3I–VII, 4I–VII, 5I–VII, 6I–VII).
13C NMR (D2O): d 133.2 (s, 1C, CH2@CH–CH2),
118.1 (s, 1C, CH2@CH–CH2), 102.4, 102.3, 102.3,
102.2, 102.2, 102.1 (6C, b-C-1), 94.1 (1C, a-C-1), 84.2,
84.1, 83.9, 83.7, 75.6, 75.2, 75.2, 73.1, 72.9, 72.8, 72.4,
69.2, 67.7, 60.4, 60.3, 60.2, (C-2 to C-6). Anal. Calcd
for C45H76O36: C, 45.30; H, 6.42. Found: C, 45.16; H,
6.32.
20
1
solid: ½aꢁ +6.4 (c 1.2, CHCl3); H NMR: d 8.01–7.11
D
(m, 45H, 9Bz-H), 5.87 (dd, 1H, J2,3 = J3,4 = 9.7Hz, H-
3VI), 5.65 (dd, 1H, J3,4 = J4,5 = 9.7Hz, H-4VI), 5.49
(dd, 1H, J1,2 8.0Hz, J2,3 9.7Hz, H-2VI), 5.46–5.37 (m,
1H, CH2@CH–CH2–), 5.09–3.14 (m, 43H, CH2@CH–
CH2–, H-1I–VI, 2II–V, 3I–V, 4I–V, 5I–VI, 6I–VI), 3.77, 3.71
(ABq, 2H, J 14.8Hz, ClCH2CO), 2.06, 2.05, 2.03, 1.98,
1.97, 1.90, 1.84 (7s, 21H, 7CH3CO). Anal. Calcd for
C
5.12.
118H117ClO48: C, 60.60; H, 5.04. Found: C, 60.72; H,
3.19. Acetonyl 4,6-di-O-acetyl-2-O-benzoyl-3-O-chloro-
acetyl-b-D-glucopyranosyl-(1!3)-2-O-benzoyl-4,6-O-
benzylidene-a-D-glucopyranoside (19)
3.17. Allyl 4,6-di-O-acetyl-2-O-benzoyl-3-O-chloroacetyl-
b-D-glucopyranosyl-(1!3)-4,6-di-O-acetyl-2-O-benzoyl-
b-D-glucopyranosyl-(1!3)-[2,3,4,6-tetra-O-benzoyl-b-D-
glucopyranosyl-(1!6)]-2-O-benzoyl-b-D-glucopyranosyl-
(1!3)-4,6-di-O-acetyl-2-O-benzoyl-b-D-glucopyranosyl-
(1!3)-[2,3,4,6-tetra-O-benzoyl-b-D-glucopyranosyl-
(1!6)]-4-O-acetyl-2-O-benzoyl-a-D-glucopyranoside (17)
To a solution of compound 4 (1.2g, 1.48mmol) in THF
(5mL) was added HOAc (75%, 5mL) containing
NaOAc (500mg, 6.10mmol), then PdCl2 (525mg,
2.96mmol) was added. The mixture was stirred at rt
overnight, and TLC (2:1 petroleum ether–EtOAc) indi-
cated that the reaction was complete. The mixture was
filtered, the filter cake was washed with CH2Cl2, and
the combined filtrate and washings were concentrated.
Purification by column chromatography with 2:1 petro-
Compound 17 (30mg, 80%) was obtained as an amor-
phous solid from compounds 16 (30mg, 0.013mmol)
and 9 (12mg, 0.16mmol) according to the general proce-
dure for the coupling reaction. However, purification
leum ether–EtOAc as the eluent afforded compound 19
20
was carried out with 1:1 petroleum ether–EtOAc as
(440mg, 36%) as a syrup: ½aꢁ +32.4 (c 0.8, CHCl3);
D
20
D
the eluent: ½aꢁ +19.8 (c 0.1, CHCl3); 1H NMR: d
1H NMR: d 7.82–7.13 (m, 15H, 2Bz–H, Ph–H), 5.61
(s, 1H, PhCH), 5.34 (dd, 1H, J2,3 = J3,4 = 9.6Hz, H-
30), 5.29 (dd, 1H, J1,2 7.8Hz, J2,3 9.6Hz, H-20), 5.17
(dd, 1H, J3,4 = J4,5 = 9.8Hz, H-40), 5.13 (d, 1H, J1,2
3.6Hz, H-1), 5.01 (dd, 1H, J1,2 3.6Hz, J2,3 9.8Hz,
H-2), 4.98 (d, 1H, J1,2 7.8Hz, H-10), 4.67 (dd, 1H,
J2,3 = J3,4 = 9.8Hz, H-3), 4.27–3.67 (m, 7H, H-4, 5, 50,
6, 60), 4.15, 4.00 (ABq, 2H, J 17.3Hz, CH2COCH3),
3.83, 3.77 (ABq, 2H, J 14.8Hz, ClCH2CO), 2.01, 2.01,
2.00 (3s, 9H, 3CH3CO). Anal. Calcd for C42H43ClO17:
C, 58.98; H, 5.07. Found: C, 59.06; H, 5.12.
8.02–7.08 (m, 65H, 13Bz–H), 5.93, 5.87 (dd, 2H,
J2,3 = J3,4 = 9.8Hz, H-3VI,VII), 5.74, 5.64 (dd, 1H,
J3,4 = J4,5 = 9.8Hz, H-4VI,VII), 5.57–5.35 (m, 3H, J1,2
8.0Hz, J2,3 9.8Hz, CH2@CH–CH2–, H-2VI,VII), 5.16–
3.18 (m, 47H, CH2@CH–CH2–, H-1I–VII, 2I–V, 3I–V
,
4I–V, 5I–VII, 6I–VII), 3.72, 3.66 (ABq, 2H, J 14.8Hz,
ClCH2CO), 2.05, 2.04, 2.00, 1.99, 1.96, 1.86, 1.77 (7s,
21H, 7CH3CO). 13C NMR: d 170.6, 170.6, 170.4,
170.2, 169.8, 169.3, 169.2 (7C, 7CH3CO), 166.1, 165.9,
165.7, 165.5, 165.2, 165.2, 165.1, 164.9, 164.8, 164.7,
163.7, 163.6, 163.4 (13C, 13BzCO), 117.30 (s, 1C,
CH2@CH–CH2), 102.0, 101.6, 101.3, 101.2, 100.8,
100.6 (6C, b-C-1), 94.3 (1C, a-C-1), 85.4, 84.5, 83.4,
82.3 (4C, 4C-3). Anal. Calcd for C152H143ClO57: C,
62.58; H, 4.94. Found: C, 62.72; H, 5.02.
3.20. Acetonyl 4,6-di-O-acetyl-2-O-benzoyl-b-D-gluco-
pyranosyl-(1!3)-2-O-benzoyl-4,6-O-benzylidene-a-D-
glucopyranoside (20)
Compound 19 (400mg, 0.485mmol) was dissolved in
mixed solvents of CH2Cl2 (4mL) and MeOH (6mL).
To the solution were added thiourea (185mg,
2.43mmol) and 2,4-lutidine (54lL, 0.49mmol), and
the reaction mixture was boiled under reflux for 16h,
at the end of which time TLC (2:1 petroleum ether–
EtOAc) indicated that the reaction was complete. The
mixture was concentrated, and extracted with CH2Cl2,
and the organic phase was washed with N HCl, satd
aq NaHCO3, and water, dried and concentrated. Purifi-
cation by column chromatography with 2:1 petroleum
ether–EtOAc as the eluent afforded 20 (330mg, 87%)
3.18. Allyl b-D-glucopyranosyl-(1!3)-b-D-glucopyrano-
syl-(1!3)-[b-D-glucopyranosyl-(1!6)]-b-D-glucopyrano-
syl-(1!3)-b-D-glucopyranosyl-(1!3)-[b-D-glucopyrano-
syl-(1!6)]-a-D-glucopyranoside (18)
Satd NH3 in MeOH (5mL) was added to compound 17
(30mg, 10.3lmol) in MeOH (4mL). After 48h at rt, the
reaction mixture was concentrated, and the residue was
purified by Sephadex LH-20 chromatography (MeOH)
to afford 18 (12mg, 98%) as an amorphous solid:
20
1
½aꢁ +2.0 (c 0.4, H2O); H NMR (D2O): d 6.05–5.95
D
20
1
(m, 1H, CH2@CH–CH2–), 5.40–5.24 (m, 2H,
as an amorphous solid: ½aꢁ +50.4 (c 1.0, CHCl3); H
D

G. Yang, F. Kong / Carbohydrate Research 340 (2005) 39–48
47
NMR: d 7.92–7.21 (m, 15H, 2Bz–H, Ph–H), 5.60 (s, 1H,
PhCH), 5.17 (d, 1H, J1,2 3.9Hz, H-1), 5.09 (dd, 1H, J1,2
7.8Hz, J2,3 9.4Hz, H-20), 5.03 (dd, 1H, J1,2 3.9Hz, J2,3
9.6Hz, H-2), 5.01 (dd, 1H, J3,4 = J4,5 = 9.4Hz, H-40),
4.98 (d, 1H, J1,2 7.8Hz, H-10), 4.51 (dd, 1H,
J2,3 = J3,4 = 9.6Hz, H-3), 4.27-3.60 (m, 8H, H-30, 4, 5,
50, 6, 60), 4.16, 4.05 (ABq, 2H, J 17.3Hz, CH2COCH3),
2.07, 2.01, 2.01 (3s, 9H, 3CH3CO). Anal. Calcd for
C40H42O16: C, 61.69; H, 5.44. Found: C, 61.76; H, 5.34.
4.35–3.30 (m, 18H, H-3I–IV, 4I,III, 5I–IV, 6I–IV), 4.09,
4.01 (ABq, 2H, J 17.3Hz, CH2COCH3), 2.01, 1.96,
1.96, 1.94, 1.92 (5s, 15H, 5CH3CO). Anal. Calcd for
C77H78O30: C, 62.34; H, 5.30. Found: C, 62.16; H, 5.14.
3.23. Acetonyl 2,3,4,6-tetra-O-benzoyl-b-D-glucopyrano-
syl-(1!3)-2-O-benzoyl-4,6-O-benzylidene-b-D-glucopyran-
osyl-(1!3)-4,6-di-O-acetyl-2-O-benzoyl-b-D-glucopyran-
osyl-(1!3)-2-O-benzoyl-4,6-O-benzylidene-b-D-gluco-
pyranosyl-(1!3)-4,6-di-O-acetyl-2-O-benzoyl-b-D-gluco-
pyranosyl-(1!3)-2-O-benzoyl-4,6-O-benzylidene-a-D-
glucopyranoside (25)
3.21. Acetonyl 4,6-di-O-acetyl-2-O-benzoyl-3-O-chloro-
acetyl-b-D-glucopyranosyl-(1!3)-2-O-benzoyl-4,6-O-
benzylidene-b-D-glucopyranosyl-(1!3)-4,6-di-O-acetyl-2-
O-benzoyl-b-D-glucopyranosyl-(1!3)-2-O-benzoyl-4,6-
O-benzylidene-a-D-glucopyranoside (22)
Compound 25 (180mg, 50%) was obtained as an amor-
phous solid from compounds 23 (220mg, 0.148mmol)
and 24 (210mg, 0.192mmol) according to the general
procedure for the coupling reaction. However, purifica-
tion was carried out with 2:1 petroleum ether–EtOAc as
Compound 22 (400mg, 71%) was obtained as an amor-
phous solid from compounds 20 (280mg, 0.36mmol)
and 21 (400mg, 0.43mmol) according to the general
procedure for the coupling reaction. However, purifica-
20
D
1
the eluent: ½aꢁ +46.9 (c 1.0, CHCl3); H NMR: d 7.92–
7.07 (m, 60H, 9Bz–H, 3Ph–H), 5.50, 5.50, 5.37 (3s, 3H,
3PhCH), 5.54 (dd, 1H, J2,3 = J3,4 = 9.5Hz, H-3VI), 5.50
(dd, 1H, J3,4 = J4,5 = 9.5Hz, H-4VI), 5.33 (dd, 1H, J1,2
8.0Hz, J2,3 9.5Hz, H-3VI), 5.09–4.62 (m, 7H, H-2I–V
,
tion by column chromatography was carried out with
20
D
2:1 petroleum ether–EtOAc as the eluent: ½aꢁ +11.1 (c
1
1.2, CHCl3); H NMR: d 7.79–7.13 (m, 30H, 4 Bz–H,
2Ph–H), 5.52, 5.48 (2s, 2H, 2PhCH), 5.12–4.92 (m,
6H, H-2II–IV, 3IV, 4II,IV), 5.05 (d, 1H, d, 1H, J1,2
3.6Hz, H-1I), 4.79, 4.64, 4.60 (3d, 3H, J1,2 7.8Hz, H-
1II–IV), 4.71 (dd, 1H, J1,2 3.6Hz, J2,3 9.6Hz, H-2I),
4.36–3.30 (m, 17H, H-3I–III, 4I,III, 5I–IV, 6I–IV), 4.08,
3.98 (ABq, 2H, J = 17.3Hz, CH2COCH3), 3.75, 3.68
(ABq, 2H, J 14.8Hz, ClCH2CO), 1.96, 1.96, 1.95, 1.93,
1.91 (5s, 15H, 5CH3CO). Anal. Calcd for C79H79ClO31:
C, 60.83; H, 5.10. Found: C, 60.76; H, 5.04.
4II,IV), 5.04 (d, 1H, J1,2 3.6Hz, H-1I), 4.79, 4.75, 4.51,
4.50, 4.43 (5d, 5H, J1,2 8.0Hz, H-1II–VI), 4.36–3.24 (m,
26H, H-3I–V, 4I,III,V, 5I–VI, 6I–VI), 4.09, 3.97 (ABq, 2H,
J 17.3Hz, CH2COCH3), 1.96, 1.96, 1.95, 1.89, 1.84 (5s,
15H, 5CH3CO). Anal. Calcd for C131H122O45: C,
65.11; H, 5.09. Found: C, 65.26; H, 5.24.
3.24. Acetonyl 2,3,4,6-tetra-O-benzoyl-b-D-glucopyranos-
yl-(1!3)-2-O-benzoyl-b-D-glucopyranosyl-(1!3)-4,6-
di-O-acetyl-2-O-benzoyl-b-D-glucopyranosyl-(1!3)-2-O-
benzoyl-b-D-glucopyranosyl-(1!3)-4,6-di-O-acetyl-2-O-
benzoyl-b-D-glucopyranosyl-(1!3)-2-O-benzoyl-a-D-
glucopyranoside (26)
3.22. Acetonyl 4,6-di-O-acetyl-2-O-benzoyl-b-D-gluco-
pyranosyl-(1!3)-2-O-benzoyl-4,6-O-benzylidene-b-D-
glucopyranosyl-(1!3)-4,6-di-O-acetyl-2-O-benzoyl-b-D-
glucopyranosyl-(1!3)-2-O-benzoyl-4,6-O-benzylidene-a-
D-glucopyranoside (23)
To a solution of compounds 25 (130mg, 0.054mmol)
and ethylene glycol (0.1mL, 1.80mmol) in MeCN
(5mL) was added p-toluenesulfonic acidÆH2O (10mg).
The mixture was stirred at rt overnight at the end of
which time TLC (1:1 petroleum ether–EtOAc) indicated
that the reaction was complete. The mixture was made
neutralized with Et3N, concentrated, and extracted with
CH2Cl2, the organic phase was washed with water, then
dried and concentrated. Purification by column chroma-
tography with 1:1 petroleum ether–EtOAc as the eluent
afforded compound 26 (80mg, 69%) as an amorphous
Compound 22 (350mg, 0.22mmol) was dissolved in
mixed solvents of CH2Cl2 (4mL) and MeOH (6mL).
To the solution were added thiourea (85mg, 1.04mmol)
and 2,4-lutidine (25lL, 0.23mmol), and the reaction
mixture was boiled under reflux for 16h, at the end of
which time TLC (1.5:1 petroleum ether–EtOAc) indi-
cated that the reaction was complete. The mixture was
concentrated and extracted with CH2Cl2, and the organic
phase was washed with N HCl, satd aq NaHCO3, and
water, dried, and concentrated. Purification by column
chromatography with 2:1 petroleum ether–EtOAc as
the eluent afforded 23 (270mg, 81%) as an amorphous
20
D
1
solid: ½aꢁ +16.3 (c 0.8, CHCl3); H NMR: d 8.08–6.97
(m, 45H, 9Bz–H), 5.68 (dd, 1H, J2,3 = J3,4 = 9.6Hz, H-
3VI), 5.51 (dd, 1H, J3,4 = J4,5 = 9.6Hz, H-4VI), 5.38
(dd, 1H, J1,2 8.0Hz, J2,3 9.6Hz, H-3VI), 5.06 (d, 1H,
J1,2 3.8Hz, H-1I), 5.03–4.62 (m, 7H, H-2I–V, 4II,IV),
4.77, 4.61, 4.59, 4.48, 4.46 (5d, 5H, J1,2 8.0Hz,
H-1II–VI), 4.35–3.14 (m, 28H, CH2COCH3, H-3I–V
4I,III,V, 5I–VI, 6I–VI), 2.08, 2.04, 1.88, 1.88, 1.82 (5s,
20
D
1
solid: ½aꢁ +20.4 (c 0.9, CHCl3); H NMR: d 7.79–7.13
(m, 30H, 4Bz–H, 2Ph–H), 5.52, 5.48 (2s, 2H, 2PhCH),
5.10–4.86 (m, 5H, H-2II–IV, 4II,IV), 5.05 (d, 1H, J1,2
3.6Hz, H-1I), 4.80, 4.64, 4.62 (3d, 3H, J1,2 7.8Hz, H-
1II–IV), 4.73 (dd, 1H, J1,2 3.6Hz, J2,3 9.6Hz, H-2I),
,

48
G. Yang, F. Kong / Carbohydrate Research 340 (2005) 39–48
15H, 5CH3CO). Anal. Calcd for C110H110O45: C, 61.39;
H, 5.15. Found: C, 61.56; H, 5.24.
(MeOH) to afford 28 as an amorphous solid (15.5mg,
1
20
98%): ½aꢁ +2.9 (c 1.0, H2O); H NMR (D2O): d 4.95
D
(d, 1H, J1,2 3.9Hz, H-1I), 4.77, 4.77, 4.76, 4.76, 4.53,
4.53, 4.49, 4.49 (8d, 8H, J1,2 8.0Hz, H-1II–IX), 4.07 (s,
3.25. Acetonyl 2,3,4,6-tetra-O-benzoyl-b-D-glucopyranos-
yl-(1!3)-[2,3,4,6-tetra-O-benzoyl-b-D-glucopyranosyl-
(1!6)]-2-O-benzoyl-b-D-glucopyranosyl-(1!3)-4,6-di-O-
acetyl-2-O-benzoyl-b-D-glucopyranosyl-(1!3)-[2,3,4,6-
tetra-O-benzoyl-b-D-glucopyranosyl-(1!6)]-2-O-benzoyl-
b-D-glucopyranosyl-(1!3)-4,6-di-O-acetyl-2-O-benzoyl-
b-D-glucopyranosyl-(1!3)-[2,3,4,6-tetra-O-benzoyl-b-D-
glucopyranosyl-(1!6)]-2-O-benzoyl-a-D-glucopyranoside
(27)
2H, CH3COCH2), 4.23–3.30 (m, 54H, H-2I–IX, 3I–IX
,
4I–IX, 5I–IX, 6I–IX), 1.99 (s, 3H, CH3CO). 13C NMR
(D2O): d 172.10 (1C, CH3COCH2), 102.6, 102.6, 102.6,
102.5, 102.3, 102.3, 102.2, 102.2 (8C, b-C-1), 97.98
(1C, a-C-1), 84.57, 84.50, 84.00, 83.80, 81.55 (5C, C-
3A–E), 21.03 (s, 1C, CH3COCH2). Anal. Calcd for
C57H96O47: C, 44.65; H, 6.31. Found: C, 44.76; H, 6.44.
Compound 27 (60mg, 55%) was obtained as an amor-
phous solid from compounds 26 (60mg, 0.0279mmol)
and 9 (75mg, 0.1mmol) according to the general proce-
dure for the coupling reaction. However, purification
Acknowledgements
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).
was carried out with 1:1.5 petroleum ether–EtOAc as
20
D
the eluent: ½aꢁ +46.9 (c 1.2, CHCl3); 1H NMR: d
8.05–6.87 (m, 105H, 21Bz–H), 5.95–5.29 (m, 12H, H-
2VI–IX, 3VI–IX, 4VI–IX), 4.97–4.37 (m, 15H, H-1II–IX, 2I–V
,
4II,IV), 4.78 (d, 1H, J1,2 3.6Hz, H-1I), 4.26–3.10 (m,
37H, CH2COCH3, H-3I–V, 4I,III,V, 5I–IX, 6I–IX), 2.03,
2.03, 1.99, 1.86, 1.81 (5s, 15H, 5CH3CO). 13C NMR: d
170.5, 170.4, 170.4, 169.3, 169.2 (5C, 5CH3CO), 166.1,
166.0, 165.9, 165.7, 165.7, 165.7, 165.6, 165.5, 165.2,
165.2, 165.1, 165.1, 165.0, 164.9, 164.9, 164.8, 164.6,
163.8, 163.5, 163.3, 163.1 (21s, 21C, BzCO), 102.1,
102.1, 101.5, 101.4, 101.4, 100.9, 100.7, 100.5 (8C, b-C-
1), 95.3 (1C, a-C-1), 22.65, 21.62, 20.63, 20.45, 20.41
(5C, 5CH3CO). Anal. Calcd for C212H188O72: C, 65.49;
H, 4.87. Found: C, 65.66; H, 4.74.
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Satd NH3 in MeOH (5mL) was added to compounds 27
(40mg, 10.29lmol) in MeOH (4mL). After 48h at rt,
the reaction mixture was concentrated, and the residue
was purified by Sephadex LH-20 chromatography