Glycosylation from the non-reducing end using a combination of thioglycoside and glycosyl sulfoxide as the glycosyl donor and the acceptor

Article abstract of DOI:10.1248/cpb.58.758

A glycosylation reaction was performed using a combination of thioglycoside and glycosyl sulfoxide, which were prepared with odorless p- octyloxybenzenethiol, as a glycosyl donor and an acceptor, respectively. Promising results were obtained when p-octyloxylphenyl N-phthaloyl-D-thio- glucosaminide was activated with N-iodosuccinimide (NIS) and triflic acid (TfOH) for glycosylation of the hydroxyl group of the C-6 position of derivatives of D-glucosyl sulfoxide. Successive reduction of the resulting disaccharyl sulfoxides provided the corresponding thioglycosides, which could be used as the glycosyl donors in another glycosylation reaction to afford trisaccharides in good yield. The present method would be useful for the block synthesis of glycosyl donors in the total synthesis of blanched oligosaccharides, especially when N-acetylglucosamines are presented at the non-reducing ends.

Full text of DOI:10.1248/cpb.58.758

758
Note
Chem. Pharm. Bull. 58(5) 758—764 (2010)
Vol. 58, No. 5
Glycosylation from the Non-reducing End Using a Combination of
Thioglycoside and Glycosyl Sulfoxide as the Glycosyl Donor and the
Acceptor
Tetsuya KAJIMOTO,*,a Kenji ARIMITSU,b Minoru OZEKI,b and Manabu NODE*,b
a Osaka University of Pharmaceutical Sciences; 4–1–20 Nasahara, Takatsuki, Osaka 569–1094, Japan: and b Kyoto
Pharmaceutical University; 1 Shichono-cho, Misasagi, Yamashina-ku, Kyoto 607–8412, Japan.
Received February 1, 2010; accepted March 2, 2010; published online March 5, 2010
A glycosylation reaction was performed using a combination of thioglycoside and glycosyl sulfoxide, which
were prepared with odorless p-octyloxybenzenethiol, as a glycosyl donor and an acceptor, respectively. Promising
results were obtained when p-octyloxylphenyl N-phthaloyl-D-thio-glucosaminide was activated with N-iodosuc-
cinimide (NIS) and triflic acid (TfOH) for glycosylation of the hydroxyl group of the C-6 position of derivatives of
D-glucosyl sulfoxide. Successive reduction of the resulting disaccharyl sulfoxides provided the corresponding thio-
glycosides, which could be used as the glycosyl donors in another glycosylation reaction to afford trisaccharides
in good yield. The present method would be useful for the block synthesis of glycosyl donors in the total synthesis
of blanched oligosaccharides, especially when N-acetylglucosamines are presented at the non-reducing ends.
Key words glycosylation; glycosyl sulfoxide; thioglycoside; odorless benzenethiol
In 1989, Kahne and his colleagues reported that phenyl
glycosyl sulfoxides could act as excellent glycosyl donors in
the presence of triflic acid (TfOH) or triflic anhydride.1)
Later, they applied the method to the one-pot synthesis of the
trisaccharide of ciclamycin, with glycosyl phenyl sulfoxides
and glycosyl p-methoxyphenyl sulfoxides employed as glyco-
syl donors and phenyl thioglycoside as an acceptor.2) However,
a glycosylation reaction using glycosyl sulfoxide as the accep-
tor with thioglycoside as the donor has not been reported to
date.
Fig. 1. Structures of Odorless Benzenethiols, Thioglycoside and Glycosyl
Meanwhile, we recently reported the usefulness of aryl
thioglycosides 1, 2 prepared with odorless benzenethiol 3,
43,4) as glycosyl donors in a glycosylation reaction, with N-
iodosuccinimide (NIS) and TfOH as the activator,3,4) as part
of our study on the development of odorless thiols and their
application in organic synthesis (Fig. 1).5—17)
Sulfoxide
Against this background, we were interested that p-octyl-
oxyphenyl glycosyl sulfoxides (5) could be easily prepared
from 2 by selective oxidation of the sulfide group. Since the
resulting oligoglycosyl sulfoxide 6 by the glycosylation reac-
tion, using 2 and 5 as the glycosyl donor and acceptor,
respectively, could be reduced to the corresponding aryl thio-
glycoside 7, which would be available as the oligoglycosyl
donor in the next step, the strategy provides a useful method
for the synthesis of oligosaccharides from the non-reducing
end (Chart 1).
Thus, in the present paper, we report the results of the gly-
cosylation reaction using a combination of 5 and 2 as the
glycosyl acceptor and donor, respectively, and its application
Chart 1. Glycosylation Using Thioglycoside 2 and Glycosyl Sulfoxide 5
for the synthesis of trisaccharides from the non-reducing- tions where thioglycosides 2c and 2e—g were employed as
end.
glycosyl donors were performed in the presence of NIS and
TfOH in dichloromethane at ꢀ50 °C (Table 1). Interestingly,
satisfactory results were obtained only when N-phthaloylglu-
Results and Discussion
First, aryl thioglycosides 2a, 2b, which were prepared cosamine derivative 2e and glucose derivatives 5a, 5b were
from p-octyloxyphenyl 2,3,4,6-tetra-O-acetyl-b-D-glucopy- employed as the donor and acceptor substrates, respectively
ranose (2c) in 4 steps, and 2d3,4) were oxidized with m- (Table 1, entries 2—4). It is noteworthy to emphasize that use
chloroperbenzoic acid (m-CPBA) to afford the corresponding of a mixture of two diastereoisomers of sulfoxide 5b gave an
glycosyl sulfoxides 5a—c (Chart 2).
almost same result comparing with the reaction using the sin-
Using 5a—c as the glycosyl acceptor, glycosylation reac- gle isomer (Table 1, entries 3, 4). Therefore, it is unnecessary
© 2010 Pharmaceutical Society of Japan
∗ To whom correspondence should be addressed. e-mail: kajimoto@gly.oups.ac.jp

May 2010
759
to separate two diastereomers of the acceptors for practical
application of the glycosylation. Other combinations of the
glycosyl donor and acceptor, e.g., 2c and 5b, gave unsatisfied
yields (ꢁ5%). In addition, the glycosylation of 5b with 2f—
g did not yield the desired product at all and donors 2f, g
were recovered in good yield (66% and 99%, respectively)
while complete consumption of the acceptor substrate 5b
was observed on monitoring the reaction.
Herein, we challenged the synthesis of a trisaccharide by
taking advantage of the reaction of 2e and 5a, b (Table 1, en-
tries 2—4). In order to apply the synthesis of disaccharides
6b, c to further glycosylation, the sulfoxide group had to be
reduced to the sulfide group. After several attempts, the com-
bination of triphenylphosphine and carbon tetrachloride
under the refluxed condition of acetonitrile18) could convert
6b and 6c to the appropriate sulfides 11a and 11b, respec-
tively, in good yield (82%, 84%). Glycosylation of methyl
2,3,4-tri-O-benzyl-a-D-glucopyranoside 12 using 11a, b as
the glycosyl donor was also achieved to afford trisaccharides
13a, b in satisfactory yield (50%, 76%), although a mixture
of a and b isomers (1 : 2.5) was produced in the former reac-
tion (Chart 3).
Conclusion
In conclusion, we found that the combination of p-
octyloxylphenyl N-phthaloyl-D-thio-glucosaminide and p-
Chart 2. Structures and Preparation of 2a—f and Glycosyl Sulfoxide 5a—c
Table 1. Glycosylation Reaction of 2 and 5
Product
Entry
Donor
Acceptor
Time (min)
Yield
b : a
Recovery
R1
R2
1
2
3
4
5
2c
2e
2e
2e
2e
5aa)
5aa)
5ba)
5bb)
5ca)
40
15
15
15
15
6a
6b
6c
OAc
NPhth
NPhth
NPhth
—
Bn
Bn
Bz
Bz
—
35%
73%
66%
59%
21%
1 : 0
1 : 0
1 : 0
1 : 0
1 : 0
5a (40%)
—
—
—
5c (46%)
6cꢂ6cꢃc)
6d
a) The less polar diastereomer on the sulfur atom was used. b) A mixture of two diastereomer was used. c) The more polar product than 6c.
Chart 3. Synthesis of Trisaccharides 13a, b

760
Vol. 58, No. 5
(2H, tt, Jꢄ1.5, 7.3 Hz), 7.37 (1H, tt, Jꢄ1.5, 7.3 Hz), 7.42 (1H, tt, Jꢄ1.5, 7.3
Hz), 7.73 (2H, d, Jꢄ8.8 Hz), 7.99 (2H, dt, Jꢄ1.5, 7.3 Hz), 8.06 (2H, dt, Jꢄ
1.5, 7.3 Hz), 8.18 (2H, dt, Jꢄ1.5, 7.3 Hz). 13C-NMR (C5D5N) d: 14.2, 22.9,
26.3, 29.43, 29.45, 29.5, 32.0, 61.6 (C-6), 68.3 (OCH2), 70.2 (C-4), 71.7 (C-
2), 75.8 (C-3), 80.3 (C-5), 86.9 (C-1), 115.6 (2C), 122.6, 128.7 (2C), 128.8
(2C), 128.9 (2C), 129.6, 129.8, 129.95 (2C), 129.99 (3C), 130.1 (2C), 133.5,
133.6, 133.7, 135.9 (2C), 160.2, 165.60, 165.64, 166.3. IR (CHCl3) n: 3526,
octyloxylphenyl D-glucosyl sulfoxide derivatives provided a
compatible set of glycosyl donor and acceptor in the glycosy-
lation reaction, where NIS and TfOH were the activating
agents. When treated with triphenyl phosphine and carbon
tetrachloride, the resulting disaccharyl sulfoxide could be
easily converted to the corresponding thioglycoside, which
was available as the glycosyl donor in other glycosylation.
Since our strategy could be repeated in further steps, it pro-
vides a novel practical method for the block synthesis of gly-
cosyl donors in the total synthesis of blanched oligosaccha-
rides, especially, in which N-acetylglucosamines are pre-
sented at the non-reducing ends.
3071, 2930, 2856, 1732, 1595, 1493, 1452, 1281, 1261 cmꢀ1
735.2608 (Calcd for C41H44O9SNa: 735.2604).
. HR-MS m/z:
p-Octyloxyphenyl 2,3,4,6-Tetra-O-acetyl-1-thio-b-D-glucopyranoside
(2c) p-Octyloxybenzenethiol (4)3,4) (6.61 g, 27.7 mmol) and boron
trifluoride etherate (3.5 ml, 27.6 mmol) were successively added to a
solution of 1,2,3,4,6-penta-O-acetyl-D-glucopyranose (4.95 g, 12.7 mmol) in
dichloromethane (50 ml) at 0 °C and the reaction mixture was stirred for
12.5 h at room temperature. The reaction was quenched by adding distilled
water and the mixture was extracted with ethyl acetate. The organic layer
was washed with a saturated aqueous solution of sodium bicarbonate and
brine, successively, dried over magnesium sulfate, and condensed in vacuo.
The residue was purified by column chromatography on silica gel (n-
hexane : ethyl acetateꢄ3 : 1) to afford 2c (6.44 g, 89%). [a]Dꢄꢀ28.0° (cꢄ
Experimental
General Melting points were taken on a micro hot-stage apparatus
(Yanagimoto) and were uncorrected. Infrared (IR) spectra were recorded on
a Shimadzu FT-IR-8300 diffraction grating infrared spectrophotometer, and
1H-NMR spectra were obtained on a Varian Unity INOVA-400 spectrometer
with tetramethylsilane as the internal standard. 13C-NMR spectra were
obtained on a Varian Unity INOVA-400 spectrometer with C5D5N as the
internal standard. Mass spectra (MS) were determined on a JEOL JMS-SX
102A QQ or a JEOL JMS-GC-mate mass spectrometer. Combustion analy-
sis was performed on a Perkin Elmer Series II CHNS/O Analyzer 2400.
Specific rotations were recorded on a Horiba SEPA-200 automatic digital
polarimeter. Flash column chromatography was performed with Silica Gel
60N (Kanto Chemical Co., Inc.). Kieselgel 60 F-254 plates (Merk) were
used for thin layer chromatography (TLC). Preparative TLC (PTLC) was
performed with a Silica gel 60 F-254 plate (0.5 mm, Merk). When necessary,
compounds were further purified using a recycled HPLC (JAI LC-908) on a
GPC column (JAIGEL 1H and 2H) after purification on silica gel.
1
1.05, CHCl3). H-NMR (C5D5N) d: 0.83 (3H, t, Jꢄ7.1 Hz), 1.22 (8H, m),
1.36 (2H, m), 1.71 (2H, quint., Jꢄ6.6 Hz), 1.978, 1.982, 2.02, 2.13 (each
3H, s), 3.90 (2H, t, Jꢄ6.6 Hz, –OCH2–), 4.13 (1H, ddd, Jꢄ10.1, 4.9, 2.4 Hz,
H-5), 4.41 (1H, dd, Jꢄ12.3, 2.4 Hz, H-6), 4.50 (1H, dd, Jꢄ12.3, 4.9 Hz, H-
6), 5.18 (1H, d, Jꢄ10.0 Hz, H-1), 5.40 (1H, dd, Jꢄ10.0, 9.5 Hz, H-2), 5.43
(1H, t, Jꢄ9.5 Hz, H-4), 5.77 (1H, t, Jꢄ9.5 Hz, H-3), 7.04, 7.75 (each 2H, d,
AB type, Jꢄ8.8 Hz, Ar). 13C-NMR (C5D5N) d: 14.2, 20.38, 20.41, 20.6,
20.7, 22.9, 26.2, 29.42, 29.43, 29.5, 32.0, 62.5 (C-6), 68.3 (OCH2), 68.9 (C-
4), 70.7 (C-2), 74.6 (C-3), 76.1 (C-5), 86.1 (C-1), 115.5 (2C), 121.8, 136.5
(2C), 160.4, 169.6, 169.7, 170.3, 170.4. IR (CHCl3) n: 3038, 2930, 2856,
1753, 1493, 1369, 1283, 1252 cmꢀ1. HR-MS m/z: 591.2234 (Calcd for
C28H40O41SNa: 591.2240).
Materials Most reagents were obtained from Wako Pure Chemical
Industries, Ltd., Nakalai Tesque, Inc., and Aldrich Chemical Inc.
b
p-Octyloxyphenyl 2,3,4,6-Tetra-O-benzyl-1-thio- -D-glucopyranoside
(2f) Sodium hydride (55% in mineral oil, 209 mg, 4.78 mmol) was added
to a solution of compound 8 in N,N-dimethylformamide (9.0 ml) and the
mixture was stirred at 0 °C for 10 min. Keeping the temperature, benzyl bro-
mide (567 ml, 4.78 mmol) was added drop wise to the reaction mixture,
which was stirred for 6 h at room temperature. After the reaction, the reac-
tion mixture was poured into ice water, which was extracted with diethyl
ether. The organic layer was successively washed with small amount of dis-
tilled water, a saturated aqueous solution of sodium thiosulfate, and brine,
dried over magnesium sulfate, and condensed in vacuo. The residue was pu-
rified by column chromatography on silica gel (n-hexane : ethyl acetateꢄ
10 : 1) to afford 2f (388 mg, 53%). [a]Dꢄꢀ4.9° (cꢄ1.10, CHCl3). 1H-NMR
(C5D5N) d: 0.84 (3H, t, Jꢄ7.4 Hz), 1.20 (8H, m), 1.38 (2H, m), 1.70 (2H,
quint., Jꢄ6.5 Hz), 3.72 (1H, dd, Jꢄ8.8, 9.7 Hz, H-2), 3.75 (1H, ddd, Jꢄ2.0,
4.2, 9.5 Hz, H-5), 3.86 (1H, t, Jꢄ8.8 Hz, H-4), 3.88 (2H, t, Jꢄ6.5 Hz,
OCH2), 3.91 (1H, dd, Jꢄ4.2, 8.8 Hz, H-6), 3.94 (1H, dd, Jꢄ2.0, 8.8 Hz, H-
6), 3.95 (1H, t, Jꢄ8.8 Hz, H-3), 4.59, 4.66 (each 1H, d, AB type, Jꢄ11.9 Hz,
OBn), 4.76 (1H, d, Jꢄ11.0 Hz, OBn), 4.96 (1H, d, Jꢄ11.0 Hz, OBn), 4.97
(1H, d, Jꢄ9.7 Hz, H-1), 4.97, 4.98, 5.04, 5.12 (each 1H, d, Jꢄ11.0 Hz,
OBn), 6.99 (2H, d, Jꢄ9.0 Hz), 7.25—7.43 (14H, m), 7.46, 7.50, 7.60 (each
2H, dt, Jꢄ1.5, 8.0 Hz), 7.84 (2H, d, Jꢄ9.0 Hz). 13C-NMR (C5D5N) d: 14.3,
22.9, 26.3, 29.5 (2C), 29.6, 32.0, 68.3 (OCH2), 69.7 (C-6), 73.5, 75.0, 75.2,
75.6 (4ꢅOBn), 78.4 (C-4), 79.4 (C-5), 81.3 (C-2), 87.0 (C-3), 88.2 (C-1),
115.6 (2C), 124.1, 127.9 (2C), 127.97, 128.01, 128.06 (2C), 128.12
(2C), 128.2 (2C), 128.4 (2C), 128.7 (6C), 128.8 (2C), 135.3 (2C), 139.17,
139.22, 139.3, 139.5, 159.8. IR (CHCl3) n: 3067, 3038, 2928, 2858, 1593,
1495, 1470, 1454, 1088, 1069 cmꢀ1. HR-MS m/z: 783.3692 (Calcd for
C48H56O6SNa: 783.3695).
p-Octyloxyphenyl 2,3,4-Tri-O-benzyl-1-thio-b-D-glucopyranoside (2a)
A solution of 4 M hydrochloric acid in 1,4-dioxane (5.0 ml) was added to a
solution of 10a (2.53 g) in 1,4-dioxane (50 ml) and the reaction mixture was
stirred for 22 h at room temperature. After the reaction, the reaction mixture
was neutralized with a saturated aqueous solution of sodium bicarbonate.
The mixture was then extracted with ethyl acetate and the organic layer was
washed with brine, dried over magnesium sulfate, and condensed in vacuo.
The residue was purified by column chromatography on silica gel (n-
hexane : ethyl acetateꢄ10 : 1 to 5 : 1) to afford compound 2a (1.71 g, 92%).
[a]Dꢄꢂ5.6° (cꢄ1.16, CHCl3). 1H-NMR (C5D5N) d: 0.83 (3H, t, Jꢄ6.5 Hz),
1.22 (8H, m), 1.35 (2H, m), 1.68 (2H, quint., Jꢄ7.0 Hz), 3.69 (1H, ddd,
Jꢄ2.5, 4.0, 9.0 Hz, H-5), 3.74 (1H, t, Jꢄ9.0 Hz, H-2), 3.86 (2H, t, Jꢄ7.0
Hz, OCH2), 3.99 (1H, t, Jꢄ9.0 Hz, H-3), 4.06 (1H, t, Jꢄ9.0 Hz, H-4), 4.14
(1H, ddd, Jꢄ4.0, 6.5, 12.0 Hz, H-6), 4.27 (1H, dd, Jꢄ6.5, 12.0 Hz, H-6),
4.96, 4.98, 5.02, 5.03, 5.05, 5.10 (each 1H, d, Jꢄ10.0 Hz, OBn), 5.04 (1H, d,
Jꢄ9.0 Hz, H-1), 6.81 (1H, t, Jꢄ6.5 Hz, OH), 6.98 (2H, d, A part of AB type,
Jꢄ8.8 Hz), 7.24—7.41 (9H, m), 7.43—7.49 (4H, m), 7.60 (2H, d, Jꢄ7.0
Hz), 7.79 (2H, d, B part of AB type, Jꢄ8.8 Hz). 13C-NMR (C5D5N) d: 14.2,
22.9, 26.3, 29.4 (2C), 29.5, 32.0, 61.4 (C-6), 68.3 (OCH2), 75.0 (OBn), 75.2
(OBn), 75.6 (OBn), 78.4 (C-4), 81.2 (C-5), 81.5 (C-2), 87.0 (C-3), 88.7(C-
1), 115.6 (2C), 124.7, 127.8, 127.9, 127.98, 128.1(2C), 128.2 (2C), 128.4
(2C), 128.7 (6C), 134.8 (2C), 139.3, 139.4, 139.6, 159.7. IR (CHCl3) n:
3589, 3007, 2930, 2860, 1593, 1495, 1470, 1454 cmꢀ1. HR-MS m/z:
693.3223 (Calcd for C41H50O6SNa: 693.3226).
p-Octyloxyphenyl 2,3,4-Tri-O-benzoyl-1-thio-b-D-glucopyranoside (2b)
A solution of 4 M hydrochloric acid in 1,4-dioxane (0.3 ml) was added to a
solution of 10b (30.3 mg, 0.032 mmol) in 1,4-dioxane (2 ml) and the re-
action mixture was stirred for 5 h at room temperature. After the reaction,
the reaction mixture was neutralized with a saturated aqueous solution of
sodium bicarbonate. The mixture was then extracted with ethyl acetate and
the organic layer was washed with brine, dried over magnesium sulfate, and
condensed in vacuo. The residue was purified by preparative thin layer chro-
matography on silica gel (n-hexane : ethyl acetateꢄ2 : 1) to afford compound
2b (19.2 mg, 85%). [a]Dꢄꢀ13.2° (cꢄ1.18, CHCl3). 1H-NMR (C5D5N) d:
0.83 (3H, t, Jꢄ7.0 Hz), 1.18 (8H, m), 1.35 (2H, m), 1.67 (2H, quint., Jꢄ
6.6 Hz), 3.84 (2H, t, Jꢄ6.6 Hz, OCH2), 4.17 (1H, dd, Jꢄ5.0, 12.5 Hz, H-6),
4.27 (1H, dd, Jꢄ2.2, 12.5 Hz, H-6), 4.44 (1H, ddd, Jꢄ2.2, 5.0, 9.9 Hz, H-5),
4.95 (1H, br, OH), 5.62 (1H, d, Jꢄ9.9 Hz, H-1), 6.01 (1H, t, Jꢄ9.9 Hz, H-2),
6.19 (1H, t, Jꢄ9.9 Hz, H-4), 6.51 (1H, t, Jꢄ9.9 Hz, H-3), 6.96 (2H, d, Jꢄ
8.8 Hz), 7.12 (2H, br tt, Jꢄ1.5, 7.3 Hz), 7.24 (3H, tt, Jꢄ1.5, 7.3 Hz), 7.31
p-Octyloxyphenyl 2,3,4,6-Tetra-O-benzoyl-1-thio- -D-glucopyranoside
(2g) Benzoic anhydride (1.21 g, 5.35 mmol) and N,N-dimethyl-4-aminopy-
ridine (0.1 mg) were added to a solution of compound 8 (379 mg, 0.894
mmol) in pyridine (10.0 ml) and the mixture was stirred at room temperature
for 17 h. The reaction mixture was poured into ice water, which was ex-
tracted with ethyl acetate. The organic layer was washed with 1 M hydrochlo-
ric acid, a saturated aqueous solution of sodium bicarbonate, brine, succes-
sively, and dried over magnesium sulfate, then evaporated. The residue was
purified by silica gel column chromatography (n-hexane : ethyl acetateꢄ
8 : 1) to afford 2g (655 mg, 90%). [a]Dꢄꢂ20.9° (cꢄ0.80, CHCl3). 1H-NMR
(C5D5N) d: 0.85 (3H, t, Jꢄ7.0 Hz), 1.23 (8H, m), 1.38 (2H, m), 1.70 (2H,
quint., Jꢄ6.6 Hz), 3.80, 3.81 (each 1H, dt, Jꢄ6.4, 9.2 Hz, OCH2), 4.69 (1H,
ddd, Jꢄ2.5, 5.0, 10.0 Hz, H-5), 4.82 (1H, dd, Jꢄ5.0, 12.2 Hz, H-6), 5.03
(1H, dd, Jꢄ2.5, 12.2 Hz, H-6), 5.62 (1H, d, Jꢄ9.9 Hz, H-1), 6.02 (1H, t, Jꢄ
b

May 2010
761
9.6 Hz, H-2), 6.17 (1H, t, Jꢄ9.6 Hz, H-4), 6.55 (1H, t, Jꢄ9.6 Hz, H-3), 6.87
(2H, d, Jꢄ11.0 Hz), 7.10 (2H, tt, Jꢄ1.5, 7.5 Hz), 7.23 (3H, tt, Jꢄ1.5, 7.5
Hz), 7.30 (2H, tt, Jꢄ1.5, 7.5 Hz), 7.37 (1H, tt, Jꢄ1.5, 7.5 Hz), 7.43 (3H, tt,
7.36, 7.42 (each 1H, tt, Jꢄ1.5, 7.0 Hz), 7.96 (2H, d, Jꢄ9.0 Hz), 8.01 (4H, tt,
Jꢄ1.5, 7.0 Hz), 8.10 (2H, dd, Jꢄ1.5, 7.0 Hz). 13C-NMR (C5D5N) d: 14.2,
22.9, 26.2, 29.3, 29.4, 29.5, 32.0, 61.2 (C-6), 68.4 (OCH2), 69.3 (C-2), 69.7
Jꢄ1.5, 7.5 Hz), 7.55 (1H, tt, Jꢄ1.5, 7.5 Hz), 7.75 (2H, d, Jꢄ11.0 Hz), 7.95, (C-4), 75.8 (C-3), 80.7 (C-5), 91.8 (C-1), 115.4 (2C), 128.4 (2C), 128.7
8.05, 8.18, 8.27 (each 2H, dt, Jꢄ1.5, 7.5 Hz). 13C-NMR (C5D5N) d: 14.3, (2C), 128.8 (4C), 129.5, 129.6, 129.8, 129.97 (2C), 130.01 (2C), 130.2 (2C),
22.9, 26.3, 29.45, 29.48, 29.6, 32.0, 63.3 (C-6), 68.3 (OCH2), 70.0 (C-4),
131.3, 133.6 (2C), 133.8, 162.4, 165.3, 165.5, 166.3. IR (CHCl3) n: 3364,
71.3 (C-2), 75.3 (C-3), 76.5 (C-5), 86.1 (C-1), 115.5 (2C), 121.5, 128.8 2930, 2856, 1738, 1593, 1497, 1452, 1279, 1259 cmꢀ1. HR-MS m/z:
(2C), 128.88 (2C), 128.93 (2C), 128.97 (2C), 129.39, 129.43, 129.9 (2C), 751.2550 (Calcd for C41H44O10SNa: 751.2553).
130.06 (2C), 130.15 (2C), 130.20 (3C), 130.4, 133.5, 133.6, 133.8 (2C),
More polar (minor) component, [a]Dꢄꢀ65.1° (cꢄ1.23, CHCl3). 1H-
136.8 (2C), 160.4, 165.6, 165.7, 166.2 (2C). IR (CHCl3) n: 3067, 2930, NMR (C5D5N) d: 0.85 (3H, t, Jꢄ7.0 Hz), 1.23 (8H, m), 1.37 (2H, m), 1.64
2856, 1732, 1595, 1493, 1273, 1109 cmꢀ1. HR-MS m/z: 839.2861 (Calcd for
(2H, quint., Jꢄ7.0 Hz), 3.56, 3.68 (each 1H, dt, AB type, Jꢄ9.1, 7.0 Hz,
OCH2), 4.19 (1H, dt, Jꢄ6.0, 12.6 Hz, H-6), 4.27 (1H, ddd, Jꢄ3.5, 7.0,
C48H48O10SNa: 839.2866).
p-Octyloxyphenyl 2,3,4-Tri-O-benzyl-b-D-glucopyranosyl Sulfoxide 12.6 Hz, H-6), 4.58 (1H, ddd, Jꢄ2.5, 5.0, 9.5 Hz, H-5), 5.57 (1H, d, Jꢄ
(5a) m-Chloroperbenzoic acid (77%, 304.9 mg, 1.36 mmol) was added to a
solution of 2a (0.87 g, 1.30 mmol) in dichloromethane (15 ml) at 0 °C and
the reaction mixture was stirred for 0.5 h with keeping the temperature.
9.5 Hz, H-1), 6.19 (1H, t, Jꢄ9.5 Hz, H-4), 6.52 (1H, t, Jꢄ9.5 Hz, H-3), 6.68
(1H, t, Jꢄ9.5 Hz, H-2), 6.84 (2H, d, Jꢄ9.0 Hz), 7.12 (2H, t, Jꢄ7.5 Hz),
7.17—7.28 (6H, m), 7.37, 7.40 (each 1H, tt, Jꢄ1.5, 7.5 Hz), 7.73 (2H, dd,
After the reaction, the reaction mixture was poured into a saturated aqueous Jꢄ1.5, 7.5 Hz), 7.78 (2H, d, Jꢄ9.5 Hz), 8.00 (4H, td, Jꢄ7.5, 1.5 Hz). 13C-
solution of sodium bicarbonate, which was extracted with ethyl acetate. The NMR (C5D5N) d: 14.2, 22.9, 26.2, 29.3, 29.4, 29.5, 32.0, 61.4 (C-6), 67.0
organic layer was successively washed with a saturated aqueous solution of (C-2), 68.1 (OCH2), 69.5 (C-4), 76.0 (C-3), 80.8 (C-5), 93.9 (C-1), 115.4
sodium thiosulfate, a saturated aqueous solution of sodium bicarbonate, and
brine, dried over magnesium sulfate, and condensed in vacuo. The residue
(2C), 126.3 (2C), 128.4 (2C), 128.7 (2C), 128.8 (2C), 129.5, 129.6, 129.7,
129.89 (2C), 129.96 (2C), 130.00 (2C), 131.1, 133.3, 133.6, 133.7, 161.6,
was purified column chromatography on silica gel (chloroform) to afford 164.8, 165.5, 166.2. IR (CHCl3) n: 3344, 3072, 2930, 2856, 1736, 1593,
compound 5a (797.8 mg, 90%).
1452, 1277, 1259 cmꢀ1. HR-MS m/z: 751.2546 (Calcd for C41H44O10SNa:
Less polar (major) component, [a]Dꢄꢀ130.0° (cꢄ0.74, CHCl3). 1H- 751.2553).
NMR (C5D5N) d: 0.84 (3H, t, Jꢄ7.0 Hz), 1.19 (8H, m), 1.34 (2H, m), 1.67
(2H, quint., Jꢄ6.6 Hz), 3.55 (1H, dt, Jꢄ2.5, 9.0 Hz, H-5), 3.85 (2H, t, Jꢄ Sulfoxide (5c) m-Chloroperbenzoic acid (77%, 40.6 mg, 0.181 mmol) was
6.6 Hz, OCH2), 4.03 (2H, br s, H2-6), 4.12 (1H, t, Jꢄ9.0 Hz, H-3), 4.21 (1H,
t, Jꢄ9.0 Hz, H-4), 4.45 (1H, t, Jꢄ9.0 Hz, H-2), 4.52 (1H, d, Jꢄ9.0 Hz, H-1),
p-Octyloxyphenyl 3-O-benzyl-4,6-O-benzylidene-a-D-mannopyranosyl
added to a solution of 2d3,4) (100.6 mg, 0.174 mmol) in dichloromethane
(4.0 ml) at 0 °C and the reaction mixture was stirred for 1 h with keeping the
5.02, 5.08 (each 2H, s, OBn), 5.19, 5.27 (each 1H, d, AB type, Jꢄ10.8 Hz, temperature. After the reaction, the reaction mixture was poured into a satu-
OBn), 6.65 (1H, br s, OH), 7.08 (2H, d, A part of AB type, Jꢄ8.8 Hz),
7.21—7.45 (11H, m), 7.48, 7.60 (each 2H, d, Jꢄ7.0 Hz), 7.89 (2H, d, B part
rated aqueous solution of sodium bicarbonate, which was extracted with
chloroform. The organic layer was successively washed with a saturated
of AB type, Jꢄ8.8 Hz). 13C-NMR (C5D5N) d: 14.2, 22.9, 26.2, 29.3, 29.4, aqueous solution of sodium thiosulfate, a saturated aqueous solution of
29.5, 31.9, 61.0 (C-6), 68.4 (OCH2), 75.0 (OBn), 75.4 (OBn), 75.6 (OBn),
77.9 (C-2), 78.1 (C-4), 81.9 (C-5), 86.7 (C-3), 93.8 (C-1), 115.2 (2C), 127.9
sodium bicarbonate, and brine, dried over magnesium sulfate, and con-
densed in vacuo. The residue was purified column chromatography on silica
(2C), 128.0 (2C), 128.08, 128.14, 128.2 (2C), 128.5 (2C), 128.7 (2C), gel (CHCl3) to afford compound 5c (90.3 mg, 87%).
128.75 (3C), 128.78 (2C), 131.8, 138.9, 139.3, 139.4, 161.9. IR (CHCl3) n:
Less polar (major) component, [a]Dꢄꢀ12.7° (cꢄ0.72, CHCl3). 1H-NMR
3352, 2928, 2858, 1593, 1497, 1454, 1256, 1101, 1088 cmꢀ1. HR-MS m/z: (C5D5N) d: 0.83 (3H, t, Jꢄ7.0 Hz), 1.20 (8H, m), 1.37 (2H, m), 1.71 (2H,
709.3179 (Calcd for C41H50O7SNa: 709.3175).
quint., Jꢄ6.6 Hz), 3.89 (1H, t, A part of AB type, Jꢄ10.0 Hz, H-6), 3.91
(2H, t, Jꢄ6.6 Hz, OCH2), 4.42 (1H, dd, B part of AB type, Jꢄ5.0, 10.0 Hz,
H-6), 4.56 (1H, dt, Jꢄ5.0, 10.0 Hz, H-5), 4.72 (1H, dd, Jꢄ10.0, 3.5 Hz, H-
More polar (minor) component, [a]Dꢄꢀ35.4° (cꢄ0.67, CHCl3). 1H-
NMR (C5D5N) d: 0.84 (3H, t, Jꢄ7.0 Hz), 1.22 (8H, m), 1.38 (2H, m), 1.70
(2H, quint., Jꢄ7.0 Hz), 3.82, 3.84 (each 1H, dt, AB type, Jꢄ2.5, 9.5 Hz, 3), 4.89 (1H, t, Jꢄ10.0 Hz, H-4), 4.90, 5.03 (each 1H, d, AB type, Jꢄ12.0
OCH2), 3.90 (1H, ddd, Jꢄ2.0, 4.0, 9.0 Hz, H-5), 4.06 (1H, t, Jꢄ9.0 Hz, H- Hz, OBn), 5.16 (1H, d, Jꢄ1.0 Hz, H-1), 5.39 (1H, ddd, Jꢄ1.0, 3.5, 4.5 Hz,
4), 4.14 (1H, t, Jꢄ9.0 Hz, H-3), 4.15 (1H, m, H-6), 4.27 (1H, ddd, Jꢄ4.0, H-2), 5.84 (1H, s, PhCHꢁ), 7.16 (2H, d, Jꢄ9.0 Hz), 7.22—7.31 (3H, m),
6.0, 12.0 Hz, H-6), 4.38 (1H, t, Jꢄ9.0 Hz, H-2), 4.89 (1H, d, Jꢄ11.0 Hz, 7.36 (1H, tt, Jꢄ1.5, 9.0 Hz), 7.42 (2H, tt, Jꢄ1.0, 9.0 Hz), 7.47 (2H, dd, Jꢄ
OBn), 4.95 (1H, d, Jꢄ12.0 Hz, OBn), 4.98 (1H, d, Jꢄ11.0 Hz, OBn), 4.99 9.0, 1.5 Hz), 7.75 (2H, dd, Jꢄ9.0, 1.0 Hz), 7.88 (2H, d, Jꢄ9.0 Hz), 7.95 (1H,
(1H, d, Jꢄ12.0 Hz, OBn), 5.00 (1H, d, Jꢄ9.0 Hz, H-1), 5.01, 5.08 (each 1H,
d, Jꢄ4.5 Hz, OH). 13C-NMR (C5D5N) d: 14.3, 22.9, 26.3, 29.40, 29.45,
d, Jꢄ11.5 Hz, OBn), 6.86 (1H, t, Jꢄ6.0 Hz, OH), 6.98 (2H, d, Jꢄ8.8 Hz), 29.54, 32.0, 66.0 (C-2), 68.5, 68.7 (OCH2 and C-6), 70.5 (C-5), 72.9 (OBn),
7.21—7.35 (11H, m), 7.39, 7.43 (each 2H, br d, Jꢄ7.0 Hz), 7.84 (2H, d, Jꢄ 77.5 (C-3), 78.8 (C-4), 101.1 (C-1), 102.1 (PhCHꢁ), 115.8 (2C), 126.9
8.8 Hz). 13C-NMR (C5D5N) d: 14.3, 22.9, 26.3, 29.4, 29.46, 29.54, 32.0,
61.3 (C-6), 68.4 (OCH2), 73.6 (OBn), 74.8 (OBn), 75.2 (OBn), 76.2 (C-2),
78.0 (C-4), 81.5 (C-5), 86.8 (C-3), 96.5 (C-1), 115.3 (2C), 127.1 (2C),
(2C), 127.0 (2C), 127.9 , 128.3 (2C), 128.56 (2C), 128.62 (2C), 129.3,
133.5, 138.6, 139.3, 162.3. IR (CHCl3) n: 3564, 2930, 2856, 1593, 1497,
1468, 1373, 1258 cmꢀ1. HR-MS m/z: 617.2546 (Calcd for C34H42O7SNa:
127.51, 127.53 (2C), 127.88, 127.93, 128.0 (2C), 128.2 (2C), 128.4 (2C), 617.2549).
128.70 (2C), 128.71 (2C), 132.8, 139.1, 139.17, 139.20, 161.6. IR (CHCl3)
n: 3314, 2930, 2856, 1593, 1497, 1468, 1456, 1258, 1132, 1092 cmꢀ1. HR-
MS m/z: 709.3170 (Calcd for C41H50O7SNa: 709.3175).
More polar (minor) component, [a]Dꢄꢂ113.4° (cꢄ0.72, CHCl3). 1H-
NMR (C5D5N) d: 0.84 (3H, t, Jꢄ7.0 Hz), 1.21 (8H, m), 1.37 (2H, m), 1.72
(2H, quint., Jꢄ6.5 Hz), 3.84 (1H, t, A part of AB type, Jꢄ10.0 Hz, H-6),
p-Octyloxyphenyl 2,3,4-Tri-O-benzoyl-b-D-glucopyranosyl Sulfoxide 3.92 (2H, td, Jꢄ6.5, 1.5 Hz, OCH2), 4.41 (1H, dd, Jꢄ10.0, 5.0 Hz, H-6),
(5b) m-Chloroperbenzoic acid (77%, 549 mg, 2.45 mmol) was added to a
solution of 2b (1.65 g, 2.31 mmol) in dichloromethane (50 ml) at 0 °C and
4.72 (1H, dd, Jꢄ9.5, 3.5 Hz, H-3), 4.86 (1H, t, Jꢄ9.5 Hz, H-4), 4.89 (1H, d,
A part of AB type, Jꢄ12.0 Hz, OBn), 4.89 (1H, dd, Jꢄ3.5, 1.0 Hz, H-2),
the reaction mixture was stirred for 1 h with keeping the temperature. After 4.98 (1H, dt, Jꢄ10.0, 5.0 Hz, H-5), 5.03 (1H, d, B part of AB type, Jꢄ12.0
the reaction, the reaction mixture was poured into a saturated aqueous solu- Hz, OBn), 5.19 (1H, d, Jꢄ1.0 Hz, H-1), 5.81 (1H, s, PhCHꢁ), 7.15 (2H, d,
tion of sodium bicarbonate, which was extracted with chloroform. The Jꢄ9.0 Hz), 7.25—7.37 (4H, m), 7.40 (2H, tt, Jꢄ7.5, 1.5 Hz), 7.46 (2H, dd,
organic layer was successively washed with a saturated aqueous solution of Jꢄ7.5, 2.0 Hz), 7.72 (2H, dt, Jꢄ7.5, 2.0 Hz), 7.81 (2H, d, Jꢄ9.0 Hz). 13C-
sodium thiosulfate, a saturated aqueous solution of sodium bicarbonate, and
brine, dried over magnesium sulfate, and condensed in vacuo. The residue
NMR (C5D5N) d: 14.3, 22.9, 26.2, 29.4, 29.45, 29.54, 32.0, 68.48, 68.51 (C-
2 and OCH2), 68.9 (C-6), 70.5 (C-5), 73.0 (OBn), 77.4 (C-3), 79.2 (C-4),
was purified column chromatography on silica gel (n-hexane : ethyl acetateꢄ 99.6 (C-1), 102.1 (PhCHꢁ), 115.8 (2C), 126.9 (2C), 127.4 (2C), 127.9,
1 : 1) to afford compound 5b (1.44 g, 85%). 128.4 (2C), 128.5 (2C), 128.7 (2C), 129.2, 132.7, 138.7, 139.3, 162.2. IR
Less polar (major) component, [a]Dꢄꢀ48.8° (cꢄ1.16, CHCl3). 1H-NMR (CHCl3) n: 3558, 2855, 1593, 1497, 1468, 1375, 1256 cmꢀ1. HR-MS m/z:
(C5D5N) d: 0.84 (3H, t, Jꢄ7.0 Hz), 1.21 (8H, m), 1.34 (2H, m), 1.66 (2H,
quint., Jꢄ6.5 Hz), 3.77, 3.82 (each 1H, dt, Jꢄ6.5, 9.5 Hz), 4.11 (1H, dd, Jꢄ
5.0, 12.5 Hz, H-6), 4.20 (1H, br d, Jꢄ2.5, 12.5 Hz, H-6), 4.41 (1H, ddd, Jꢄ
617.2545 (Calcd for C34H42O7SNa: 617.2549).
2,3,4,6-Tetra-O-acetyl-D-glucopyranosyl-b(1—6)-2,3,4-tri-O-benzyl-b-
D-glucopyranosyl p-Octyloxyphenyl Sulfoxide (6a) N-Iodosuccinimide
2.5, 5.0, 9.5 Hz, H-5), 5.36 (1H, d, Jꢄ9.5 Hz, H-1), 6.29 (1H, t, Jꢄ9.5 Hz, (20.1 mg, 0.089 mmol) and a quite small amount of triflic acid (1 drop with a
H-4), 6.49 (1H, t, Jꢄ9.5 Hz, H-2), 6.55 (1H, t, Jꢄ9.5 Hz, H-3), 7.00 (1H,
br s, OH), 7.06 (2H, d, Jꢄ9.0 Hz), 7.15 (2H, tt, Jꢄ1.5, 7.0 Hz), 7.22 (2H,
capillary) were added to a suspension of 2c (21.9 mg, 0.039 mmol), 5a (the
less polar isomer) (24.0 mg, 0.035 mmol), and molecular sieves 4A (MS 4A)
br t, Jꢄ7.0 Hz), 7.25 (1H, dd, Jꢄ7.0, 1.5 Hz), 7.29 (2H, tt, Jꢄ1.5, 7.0 Hz), (150 mg) in dichloromethane (3 ml) at ꢀ50 °C. After stirring the mixture for

762
Vol. 58, No. 5
2 h while keeping the temperature, the reaction mixture was filtered through
Hyflo super® which was washed with ethyl acetate. The filtrate was diluted
with an aqueous solution of sodium bicarbonate and sodium thiosulfate, and
extracted with ethyl acetate. The organic layer was washed with brine, dried
over magnesium sulfate, and evaporated. The residue was purified by silica
gel column chromatography (n-hexane/ethyl acetateꢄ2 : 1) to afford 6a
(12.3 mg, 35%). [a]Dꢄꢀ38.2° (cꢄ0.30, CHCl3). 1H-NMR (C5D5N) d: 0.84
(3H, t, Jꢄ6.8 Hz), 1.22 (8H, m), 1.43 (2H, m), 1.78 (2H, quint., Jꢄ6.5 Hz),
2.01 (6H, s, 2ꢅAc), 2.02, 2.04 (each 3H, s, Ac), 3.72 (1H, dt, Jꢄ3.5, 9.5 Hz,
sulfox-Glc-5), 3.92 (1H, t, Jꢄ9.5 Hz, sulfox-Glc-4), 4.00—4.12 (5H, m, sul-
fox-Glc-6, sulfox-Glc-3, OCH2), 4.18 (1H, ddd, Jꢄ2.8, 4.3, 9.5 Hz, Glc-5),
4.40 (1H, t, Jꢄ9.5 Hz, sulfox-Glc-2), 4.49 (1H, d, Jꢄ9.5 Hz, sulfox-Glc-1),
4.53 (1H, dd, Jꢄ2.8, 12.2 Hz, Glc-6), 4.58 (1H, dd, Jꢄ4.3, 12.2 Hz, Glc-6),
4.79 (1H, d, Jꢄ11.0 Hz, OBn), 4.97 (1H, d, Jꢄ8.0 Hz, Glc-1), 4.98 (1H, d,
Jꢄ10.8 Hz, OBn), 5.01, 5.06 (each 1H, d, Jꢄ11.5 Hz, AB type, OBn), 5.17,
5.26 (each 1H, d, Jꢄ10.9 Hz, AB type, OBn), 5.42 (1H, dd, Jꢄ8.0, 9.5 Hz,
Glc-2), 5.48 (1H, t, Jꢄ9.5 Hz, Glc-4), 5.69 (1H, t, Jꢄ9.5 Hz, Glc-3), 7.27—
7.42 (13H, m), 7.47, 7.59 (each 2H, br d, Jꢄ7.5 Hz), 7.97 (2H, d, Jꢄ8.8 Hz).
13C-NMR (C5D5N) d: 14.3, 20.47, 20.50, 20.6, 20.7, 22.9, 26.3, 29.5 (2C),
29.6, 32.0, 62.6 (Glc-6), 68.5, 68.97, 69.01 (sulfox-Glc-6, Glc-4, OCH2),
72.3 (2C) (Glc-2 and 5), 73.7 (Glc-3), 75.0, 75.4, 75.6 (OBn), 77.7 (sulfox-
Glc-2), 78.1 (sulfox-Glc-4), 80.0 (sulfox-Glc-5), 86.5 (sulfox-Glc-3), 93.3
(sulfox-Glc-1), 101.4 (Glc-1), 115.4 (2C), 128.0, 128.06 (3C), 128.15 (2C),
128.24 (3C), 128.5 (3C), 128.8 (5C), 131.6, 138.8, 138.9, 139.1, 162.1,
169.7, 169.8, 170.3, 170.6. IR (CHCl3) n: 1755, 1593, 1497, 1366, 1258,
1097 cmꢀ1. HR-MS m/z: 1039.4132 (Calcd for C55H68O16SNa: 1039.4126).
3,4,6-Tri-O-acetyl-2-N-phthaloyl-b(1—6)-D-glucosaminyl-2,3,4-tri-O-
benzyl-b-D-glucopyranosyl p-Octyloxyphenyl Sulfoxide (6b) N-Iodosuc-
cinimide (22.6 mg, 0.10 mmol) and a quite small amount of triflic acid (1
drop with a capillary) were added to a suspension of 2e (33.0 mg, 0.053
mmol), 5a (the less polar isomer) (26.2 mg, 0.038 mmol), and molecular
sieves 4A (MS 4A) (150 mg) in dichloromethane (3 ml) at ꢀ50 °C. After
stirring the mixture for 15 min. while keeping the temperature, the reaction
mixture was filtered through Hyflo super® which was washed with ethyl ac-
etate. The filtrate was diluted with an aqueous solution of sodium bicarbon-
ate and sodium thiosulfate, and extracted with ethyl acetate. The organic
layer was washed with brine, dried over magnesium sulfate, and evaporated.
The residue was purified by silica gel column chromatography (n-hexane/
ethyl acetateꢄ2 : 1) to afford 6b (30.8 mg, 73%). [a]Dꢄꢀ32.2° (cꢄ0.62,
CHCl3). 1H-NMR (C5D5N) d: 0.83 (3H, t, Jꢄ7.0 Hz), 1.23 (8H, m), 1.44
(2H, m), 1.80 (2H, quint., Jꢄ7.0 Hz), 1.83, 1.98, 2.10 (each 3H, s, OAc),
3.58 (1H, br d, Jꢄ9.0 Hz, Glc-5), 3.96—4.16 (6H, m), 4.38 (1H, br q, Jꢄ
9.5 Hz, GlcN-5), 4.41 (1H, d, Jꢄ9.5 Hz, Glc-1), 4.41 (1H, m), 4.64 (1H, d,
Jꢄ11.0 Hz, OBn), 4.70, 4.74 (each 1H, d, AB type, Jꢄ9.0 Hz, GlcN-6H2),
4.76 (1H, d, Jꢄ11.0 Hz, OBn), 4.85 (1H, dd, Jꢄ8.5, 9.0 Hz, GlcN-2), 4.94,
5.01 (each 1H, d, AB type, Jꢄ11.5 Hz, OBn), 5.15, 5.26 (each 1H, d, AB
type, Jꢄ11.0 Hz, OBn), 5.63 (1H, t, Jꢄ10.0, 9.5 Hz, GlcN-4), 5.97 (1H, d,
Jꢄ8.5 Hz, GlcN-1), 6.35 (1H, dd, Jꢄ10.0, 9.0 Hz, H-3, GlcN), 7.17—7.44
(14H, m), 7.51 (2H, dd, Jꢄ3.0, 5.5 Hz), 7.57 (3H, br t, Jꢄ7.5 Hz), 7.80 (2H,
dd, Jꢄ5.0, 3.0 Hz), 8.02 (2H, d, Jꢄ9.0 Hz). 13C-NMR (C5D5N) d: 14.2,
20.3, 20.5, 20.8, 22.9, 26.3, 29.48, 29.53, 29.6, 32.0, 55.7 (GlcN-2), 62.6
(GlcN-6), 68.6 (OCH2), 69.5 (2C) (GlcN-4 and Glc-6), 71.6 (GlcN-3), 72.6
(GlcN-5), 74.9 (OBn), 75.3 (OBn), 75.6 (OBn), 77.6 (Glc-2), 77.9 (Glc-4),
79.6 (Glc-5), 86.5 (Glc-3), 93.4 (Glc-1), 99.5 (GlcN-1), 115.4 (2C), 127.88,
127.91, 127.98 (3C), 128.10 (3C), 128.14, 128.4, 128.5 (3C), 128.6 (3C),
128.7 (3C), 128.8 (3C), 131.6, 131.7, 134.7 (2C), 138.7, 138.8, 139.2, 162.2,
169.8, 170.5, 170.7. IR (CHCl3) n: 1747, 1719, 1593, 1497, 1387, 1366,
1252 cmꢀ1. HR-MS m/z: 1126.4229 (Calcd for C61H69NO16SNa: 1126.4235).
3,4,6-Tri-O-acetyl-2-N-phthaloyl-b(1—6)-D-glucosaminyl-2,3,4-tri-O-
benzoyl-b-D-glucopyranosyl p-Octyloxyphenyl Sulfoxide (6c) N-Io-
dosuccinimide (23.8 mg, 0.106 mmol) and a quite small amount of triflic
acid (1 drop with a capillary) were added to a suspension of 2e (41.6 mg,
0.063 mmol), 5b (the less polar diastereomer) (30.7 mg, 0.042 mmol), and mo-
lecular sieves 4A (MS 4A) (150 mg) in dichloromethane (3 ml) at ꢀ50 °C.
After stirring the mixture for 15 min while keeping the temperature, the re-
action mixture was filtered through Hyflo super® which was washed with
ethyl acetate. The filtrate was diluted with an aqueous solution of sodium bi-
carbonate and sodium thiosulfate, and extracted with ethyl acetate. The or-
ganic layer was washed with brine, dried over magnesium sulfate, and evap-
orated. The residue was purified by silica gel column chromatography (n-
hexane/ethyl acetateꢄ1 : 1) and preparative thin layer chromatography (n-
hexane/ethyl acetateꢄ1 : 1) to afford 6c (32.1 mg, 66%). [a]Dꢄꢀ57.8° (cꢄ
OAc), 4.00, 4.02 (each 1H, dt, AB type, Jꢄ6.6, 9.3 Hz, OCH2), 4.09 (1H,
dd, Jꢄ5.5, 11.8 Hz, Glc-6), 4.25 (1H, ddd, Jꢄ2.5, 4.5, 9.5 Hz, GlcN-5), 4.30
(1H, dd, Jꢄ2.0, 11.8 Hz, Glc-6), 4.51 (1H, dd, Jꢄ2.5, 12.5 Hz, GlcN-6),
4.53 (1H, ddd, Jꢄ2.0, 5.5, 9.5 Hz, Glc-5), 4.60 (1H, dd, Jꢄ4.5, 12.5 Hz,
GlcN-6), 4.84 (1H, dd, Jꢄ8.4, 10.0 Hz, GlcN-2), 5.31 (1H, d, Jꢄ9.5 Hz,
Glc-1), 5.54 (1H, t, Jꢄ9.5 Hz, GlcN-4), 5.91 (1H, t, Jꢄ9.5 Hz, Glc-4), 6.01
(1H, d, Jꢄ10.0 Hz, GlcN-1), 6.28 (1H, dd, Jꢄ8.4, 9.5 Hz, GlcN-3), 6.30
(1H, t, Jꢄ9.5 Hz, Glc-2), 6.43 (1H, t, Jꢄ9.5 Hz, Glc-3), 7.08 (2H, t, Jꢄ8.0
Hz), 7.15—7.28 (5H, m), 7.32 (2H, d, Jꢄ9.0 Hz), 7.34 (1H, tt, Jꢄ1.3, 7.5
Hz), 7.39 (1H, tt, Jꢄ1.3, 7.5 Hz), 7.56 (2H, dd, Jꢄ3.0, 5.5 Hz), 7.79 (2H, dd,
Jꢄ1.3, 8.2 Hz), 7.87 (2H, dd, Jꢄ1.3, 7.5 Hz), 7.87 (2H, m), 8.04 (2H, d, Jꢄ
9.0 Hz), 8.07 (2H, dt, Jꢄ1.3, 7.5 Hz). 13C-NMR (C5D5N) d: 14.3, 20.2, 20.4,
20.8, 22.9, 26.3, 29.5 (2C), 29.6, 32.0, 55.4 (GlcN-2), 62.5 (GlcN-6), 68.6
(Glc-6), 69.0 (Glc-2 and OCH2), 69.4 (Glc-4), 69.5 (GlcN-4), 71.5 (GlcN-
3), 72.5 (GlcN-5), 75.3 (Glc-3), 78.2 (Glc-5), 90.3 (Glc-1), 98.9 (GlcN-1),
115.5 (2C), 128.7 (6C), 128.77 (4C), 128.80 (3C), 129.2, 129.3, 129.7,
129.9 (2C), 130.0 (2C), 130.2 (2C), 130.8, 132.1, 133.6, 133.7 (2C), 134.6
(2C), 162.6, 165.2, 165.3, 166.2, 169.8, 170.4, 170.6. IR (CHCl3) n: 1740,
1720, 1593, 1495, 1452, 1389, 1367, 1279, 1259 cmꢀ1. HR-MS m/z:
1168.3617 (Calcd for C61H63NO19SNa: 1168.3613).
3,4,6-Tri-O-acetyl-2-N-phthaloyl-b(1—6)-D-glucosaminyl-2,3,4-tri-O-
benzoyl-b-D-glucopyranosyl p-Octyloxyphenyl Sulfoxide (6cꢀ) N-Io-
dosuccinimide (24.4 mg, 0.109 mmol) and a quite small amount of triflic
acid (1 drop with a capillary) were added to a suspension of 2e (42.8 mg,
0.065 mmol), 5b (a mixture of two diastereomers on the sulfur atom)
(31.6 mg, 0.043 mmol), and molecular sieves 4A (MS 4A) (150 mg) in
dichloromethane (3 ml) at ꢀ50 °C. After stirring the mixture for 15 min.
while keeping the temperature, the reaction mixture was filtered through
Hyflo super® which was washed with ethyl acetate. The filtrate was diluted
with an aqueous solution of sodium bicarbonate and sodium thiosulfate, and
extracted with ethyl acetate. The organic layer was washed with brine, dried
over magnesium sulfate, and evaporated. The residue was purified by silica
gel column chromatography (n-hexane/ethyl acetateꢄ2 : 1) to afford 6c
(16.3 mg) and more polar component 6cꢃ (12.9 mg) (Total 59%). [a]Dꢄ
ꢂ20.7° (cꢄ0.78, CHCl3). 1H-NMR (C5D5N) d: 0.85 (3H, t, Jꢄ7.0 Hz), 1.24
(8H, m), 1.39 (2H, m), 1.69 (2H, quint., Jꢄ6.6 Hz), 1.83, 1.99, 2.08 (each
3H, s, OAc), 3.65, 3.78 (each 1H, dt, AB type, Jꢄ6.6, 9.0 Hz, OCH2), 4.09
(1H, dd, Jꢄ6.6, 11.5 Hz, Glc-6), 4.18 (1H, ddd, Jꢄ2.5, 4.5, 10.0 Hz, GlcN-
5), 4.37 (1H, dd, Jꢄ2.0, 11.5 Hz, Glc-6), 4.39 (1H, dd, Jꢄ2.5, 12.3 Hz,
GlcN-6), 4.60 (1H, ddd, Jꢄ2.0, 6.6, 9.2 Hz, Glc-5), 4.62 (1H, dd, Jꢄ4.5,
12.3 Hz, GlcN-6), 4.90 (1H, dd, Jꢄ8.5, 10.8 Hz, GlcN-2), 5.36 (1H, d, Jꢄ
9.2 Hz, Glc-1), 5.57 (1H, t, Jꢄ10.0 Hz, GlcN-4), 5.81 (1H, t, Jꢄ9.2 Hz, Glc-
4), 6.05 (1H, d, Jꢄ8.5 Hz, GlcN-1), 6.34 (1H, dd, Jꢄ9.2, 10.0 Hz, GlcN-3),
6.38 (1H, t, Jꢄ9.2 Hz, Glc-3), 6.50 (1H, t, Jꢄ9.2 Hz, Glc-2), 6.92 (2H, d,
Jꢄ9.0 Hz), 7.10 (2H, br t, Jꢄ7.3 Hz), 7.17—7.25 (5H, m), 7.35, 7.38 (each
1H, tt, Jꢄ1.3, 7.5 Hz), 7.55 (2H, dd, Jꢄ3.5, 5.5 Hz), 7.68 (2H, d, Jꢄ9.0 Hz),
7.71 (2H, dd, Jꢄ1.3, 8.5 Hz), 7.82 (2H, dd, Jꢄ1.3, 8.5 Hz), 7.89 (2H, dd, Jꢄ
1.3, 8.5 Hz), 7.92 (2H, dt, Jꢄ3.1, 8.5 Hz). 13C-NMR (C5D5N) d: 14.3, 20.2,
20.4, 20.7, 22.9, 26.3, 29.4, 29.5, 29.6, 32.0, 55.4 (GlcN-2), 62.4 (GlcN-6),
67.0 (Glc-2), 68.3 (OCH2), 68.6 (Glc-6), 69.3 (Glc-4), 69.5 (GlcN-4), 71.4
(GlcN-3), 72.4 (GlcN-5), 75.4 (Glc-3), 78.3 (Glc-5), 93.7 (Glc-1), 98.9
(GlcN-1), 115.4 (2C), 123.9, 124.0, 126.5 (2C), 128.4 (2C), 128.7 (2C),
128.8 (2C), 129.2, 129.3, 129.6, 129.9 (6C), 130.0 (3C), 131.1, 132.1, 133.4,
133.6, 133.7, 134.7 (2C), 161.7, 164.7, 165.3, 166.1, 169.8, 170.4, 170.5. IR
(CHCl3) n: 1740, 1720, 1595, 1495, 1452, 1389, 1367, 1277, 1259 cmꢀ1
HR-MS m/z: 1168.3618 (Calcd for C61H63NO19SNa: 1168.3613).
.
3,4,6-Tri-O-acetyl-2-N-phthaloyl-b(1—2)-D-glucosaminyl-3-O-benzyl-
(4,6)-benzylidene-b-D-mannopyranosyl p-Octyloxyphenyl Sulfoxide (6d)
N-Iodosuccinimide (19.8 mg, 0.088 mmol) and a quite small amount of tri-
flic acid (1 drop with a capillary) were added to a suspension of 2e (35.0 mg,
0.053 mmol), 5c (the less polar isomer) (21.1 mg, 0.036 mmol), and molecu-
lar sieves 4A (MS 4A) (150 mg) in dichloromethane (3 ml) at ꢀ50 °C. After
stirring the mixture for 2 h while keeping the temperature, the reaction mix-
ture was filtered through Hyflo super® which was washed with ethyl acetate.
The filtrate was diluted with an aqueous solution of sodium bicarbonate and
sodium thiosulfate, and extracted with ethyl acetate. The organic layer was
washed with brine, dried over magnesium sulfate, and evaporated. The
residue was purified by preparative silica gel thin layer chromatography
(n-hexane/ethyl acetateꢄ2 : 1, 5 times development) to afford 6d (7.4 mg,
21%). [a]Dꢄꢂ30.5° (cꢄ0.15, CHCl3). 1H-NMR (C5D5N) d: 0.85 (3H, t, Jꢄ
7.0 Hz), 1.24 (8H, m), 1.45 (2H, m), 1.80 (2H, quint., Jꢄ6.6 Hz), 1.83, 2.01,
2.06 (each 3H, s, OAc), 3.26 (1H, t, Jꢄ9.5 Hz, Man-6), 3.88 (1H, ddd, Jꢄ
2.3, 4.5, 9.6 Hz, GlcN-5), 4.01 (1H, m, Man-6), 4.02 (1H, t, Jꢄ7.0 Hz,
OCH2), 4.06 (1H, dd, Jꢄ6.5, 9.5 Hz, Man-6), 4.29 (1H, dd, Jꢄ2.3, 12.2 Hz,
1
0.87, CHCl3). H-NMR (C5D5N) d: 0.85 (3H, t, Jꢄ7.0 Hz), 1.23 (8H, m),
1.44 (2H, m), 1.78 (2H, quint., Jꢄ6.6 Hz), 1.85, 1.98, 2.14 (each 3H, s,

May 2010
763
GlcN-6), 4.35 (1H, t, Jꢄ10.2 Hz, Man-4), 4.35 (1H, m, Man-5), 4.57 (1H,
dd, Jꢄ4.5, 12.2 Hz, GlcN-6), 4.69 (1H, dd, Jꢄ3.6, 9.7 Hz, Man-3), 4.78
(1H, br s, Man-1), 4.79 (1H, d, Jꢄ11.7 Hz, OBn), 4.92 (1H, dd, Jꢄ8.5, 10.7
Hz, GlcN-2), 5.02 (1H, d, Jꢄ11.7 Hz, OBn), 5.22 (1H, dd, Jꢄ3.6, 0.5 Hz,
Man-2), 5.50 (1H, s, PhCHꢁ), 5.58 (1H, t, Jꢄ9.6 Hz, GlcN-4), 5.82 (1H, d,
Jꢄ8.5 Hz, GlcN-1), 6.32 (1H, dd, Jꢄ9.6, 10.7 Hz, GlcN-3), 7.25 (1H, tt, Jꢄ
2.0, 7.5 Hz), 7.26 (2H, d, Jꢄ8.6 Hz), 7.32 (3H, tt, Jꢄ7.0, 2.0 Hz), 7.35 (3H,
tt, Jꢄ2.3, 7.5 Hz), 7.54 (3H, m), 7.58 (4H, m), 7.79 (2H, d, Jꢄ8.6 Hz). 13C-
NMR (C5D5N) d: 14.3, 20.2, 20.4, 20.6, 22.9, 26.3, 29.4, 29.5, 29.6, 32.0,
55.2 (GlcN-2), 62.1 (GlcN-6), 68.2 (Man-6), 68.8 (OCH2), 69.4 (GlcN-4),
70.2 (Man-5), 71.1 (GlcN-3), 71.4 (OBn), 72.2 (Man-2), 72.9 (GlcN-5),
75.3 (Man-3), 77.9 (Man-4), 96.9, 97.0 (GlcN-1 and Man-1), 102.1
77%). [a]Dꢄꢂ16.1° (cꢄ1.01, CHCl3). 1H-NMR (C5D5N) d: 0.84 (3H, t, Jꢄ
7.0 Hz), 1.22 (8H, m), 1.38 (2H, m), 1.71 (2H, quint., Jꢄ6.6 Hz), 3.45 (1H,
dd, Jꢄ4.2, 10.6 Hz, H-6), 3.70 (1H, dd, Jꢄ1.8, 10.6 Hz, H-6), 3.87 (2H, t,
Jꢄ6.6 Hz, OCH2), 4.41 (1H, ddd, Jꢄ1.8, 4.2, 9.9 Hz, H-5), 5.59 (1H, d, Jꢄ
9.9 Hz, H-1), 6.09 (1H, t, Jꢄ9.9 Hz, H-2), 6.25 (1H, t, Jꢄ9.9 Hz, H-4), 6.43
(1H, t, Jꢄ9.9 Hz, H-3), 7.05—7.26 (16H, m), 7.31 (2H, br t, Jꢄ7.5 Hz),
7.39 (1H, tt, Jꢄ1.5, 7.5 Hz), 7.43 (1H, tt, Jꢄ1.5, 7.5 Hz), 7.69 (6H, dt, Jꢄ
1.5, 7.5 Hz), 7.85 (2H, dt, Jꢄ1.5, 7.5 Hz), 7.95 (4H, dt, Jꢄ1.5, 7.5 Hz), 8.18
(2H, dt, Jꢄ1.5, 7.5 Hz). 13C-NMR (C5D5N) d: 14.3, 22.9, 26.3, 29.5 (2C),
29.6, 32.0, 62.5 (C-6), 68.3 (OCH2), 69.5 (C-4), 71.6 (C-2), 75.8 (C-3), 78.1
(C-5), 86.3 (C-1), 87.0 (CPh3), 115.7 (2C), 121.7, 127.4 (3C), 128.3 (6C),
128.69 (2C), 128.72 (2C), 129.0 (2C), 129.1 (6C), 129.5, 129.7, 129.97
(PhCH<), 116.0 (2C), 126.8 (2C), 126.9 (3C), 127.9, 128.4 (3C), 128.5 (2C), 130.0 (3C), 130.2 (2C), 133.6 (3C), 133.8, 136.9 (2C), 144.4 (2C),
(3C), 128.6 (3C), 129.3, 131.8, 132.8, 134.7 (2C), 138.2, 139.0, 162.5 (2C), 160.5, 165.3, 165.6, 166.2. IR (CHCl3) n: 3065, 2930, 2856, 1732, 1595,
169.7, 170.4, 170.5. IR (CHCl3) n: 1749, 1719, 1593, 1497, 1367, 1258,
1493, 1450, 1281, 1261 cmꢀ1
C60H58O9SNa: 977.3699).
.
HR-MS m/z: 977.3693 (Calcd for
1107 cmꢀ1. HR-MS m/z: 1034.3606 (Calcd for C54H61NO16SNa: 1034.3609).
p-Octyloxyphenyl 3,4,6-Tri-O-acetyl-2-N-phthaloyl-
b(1—6)-D-glucos-
p-Octyloxyphenyl 6-O-Trityl-1-thio-b-D-glucopyranoside (9) Trityl
b-D-glucopyranoside (11a) A solution
chloride (2.49 g, 8.93 mmol) and N,N-dimethylaminopyridine (10.0 mg) aminyl-1-thio-2,3,4-tri-O-benzyl-
were added to a solution of 83,4) (3.53 g) in pyridine (40 ml) and the mixture
of triphenylphosphine (68.8 mg, 0.26 mmol) in carbon tetrachloride (1.0 ml)
was stirred at the reflux temperature for 5.5 h. After the reaction, distilled was added to a solution of 6b (29.0 mg, 0.026 mmol) in acetonitrile (2.0 ml),
water was added to the reaction mixture, which was then extracted with which was stirred for 2 h under refluxing condition. After the reaction, the
chloroform. The organic layer was washed with brine, dried over magnesium reaction mixture was poured into a saturated aqueous solution of sodium bi-
sulfate, and condensed in vacuo. The residue was purified by column chro- carbonate and extracted with ethyl acetate. The organic layer was extracted
matography on silica gel (n-hexane : ethyl acetateꢄ1 : 2) to afford compound
with ethyl acetate, washed with brine, dried over magnesium sulfate, and
9 (3.33 g, 84%). [a]Dꢄꢀ17.3° (cꢄ1.03, CHCl3). 1H-NMR (C5D5NꢂD2O) evaporated. The residue was purified by preparative silica gel thin layer
d: 0.84 (3H, t, Jꢄ7.0 Hz), 1.21 (8H, m), 1.38 (2H, m), 1.71 (2H, quint., Jꢄ chromatography (n-hexane : ethyl acetateꢄ3 : 1) to afford 11a (23.3 mg,
6.5 Hz), 3.73 (1H, dd, Jꢄ4.0, 9.5 Hz, H-6), 3.87 (2H, t, Jꢄ6.5 Hz, OCH2), 82%). [a]Dꢄꢂ6.3° (cꢄ0.73, CHCl3). 1H-NMR (C5D5N) d: 0.83 (3H, t,
3.91 (1H, br d, Jꢄ9.5 Hz, H-6), 4.00 (1H, t, Jꢄ9.5 Hz, H-4), 4.02 (1H, d, Jꢄ Jꢄ7.0 Hz), 1.20 (8H, m), 1.42 (2H, m), 1.76 (2H, quint., Jꢄ6.6 Hz), 1.83,
4.0 Hz, H-5), 4.08 (1H, t, Jꢄ9.5 Hz, H-2), 4.21 (1H, t, Jꢄ9.5 Hz, H-3), 5.24
2.01, 2.05 (each 3H, s, 3ꢅAc), 3.55 (1H, t, Jꢄ9.5 Hz, Glc-2), 3.61 (1H, t,
(1H, dd, Jꢄ0.5, 9.5 Hz, H-1), 7.02 (2H, d, Jꢄ9.0 Hz), 7.24 (3H, tt, Jꢄ1.3, Jꢄ9.5 Hz, Glc-4), 3.74 (1H, ddd, Jꢄ1.8, 4.7, 9.5 Hz, Glc-5), 3.83 (1H, t,
7.3 Hz), 7.33 (6H, br t, Jꢄ7.3 Hz), 7.54 (6H, br d, Jꢄ7.3 Hz), 8.04 (2H, d, Jꢄ9.5 Hz, Glc-3), 3.98—4.09 (3H, m, Glc-6 and A part of AB type, OCH2),
Jꢄ9.0 Hz). 13C-NMR (C5D5N) d: 14.2, 22.9, 26.3, 29.46 (2C), 29.54, 32.0, 4.15 (1H, ddd, Jꢄ2.4, 4.6, 10.0 Hz, GlcN-5), 4.42 (1H, dd, Jꢄ1.8, 10.8 Hz,
65.0 (C-6), 68.2 (OCH2), 71.5 (C-4), 73.8 (C-2), 80.3 (C-3), 80.5 (C-5), 86.8
B part of AB type, OCH2), 4.44 (1H, dd, Jꢄ2.4, 12.2 Hz, GlcN-6), 4.55 (1H,
(Ph3C), 90.0 (C-1), 115.5 (2C), 125.1, 127.3 (2C), 128.2 (6C), 129.3 (6C), d, Jꢄ10.5 Hz, OBn), 4.60 (1H, dd, Jꢄ4.6, 12.2 Hz, GlcN-6), 4.71 (1H, d, Jꢄ
135.1 (3C), 145.1 (3C), 159.5. IR (CHCl3) n: 3584, 3065, 2930, 2856, 1593,
1493, 1285, 1248 cmꢀ1. HR-MS m/z: 665.2918 (Calcd for C39H46O6SNa:
665.2913).
p-Octyloxyphenyl 2,3,4-Tri-O-benzyl-6-O-trityl-1-thio-b-D-glucopyra-
noside (10a) Sodium hydride (55% in mineral oil, 1.57 g, 36.0 mmol) was
10.5 Hz, OBn), 4.81 (1H, d, Jꢄ10.8 Hz, OBn), 4.83 (1H, d, Jꢄ9.5 Hz, Glc-
1), 4.84 (1H, d, Jꢄ11.5 Hz, OBn), 4.92 (1H, d, Jꢄ11.5 Hz, OBn), 4.95 (1H,
dd, Jꢄ8.5, 10.5 Hz, GlcN-2), 5.01 (1H, d, Jꢄ10.8 Hz, OBn), 5.61 (1H, dd,
Jꢄ9.2, 10.0 Hz, GlcN-4), 6.00 (1H, d, Jꢄ8.5 Hz, GlcN-1), 6.36 (1H, dd, Jꢄ
9.2, 10.5 Hz, GlcN-3), 7.18 (2H, d, Jꢄ8.8 Hz), 7.23—7.38 (14H, m), 7.46
added to a solution of compound 9 in N,N-dimethylformamide (30 ml) and (2H, dd, Jꢄ3.1, 5.5 Hz), 7.54 (2H, br d, Jꢄ1.3, 8.4 Hz), 7.75 (2H, dd, Jꢄ3.2,
the mixture was stirred at 0 °C for 30 min. Keeping the temperature, benzyl
bromide (2.0 ml, 16.8 mmol) was added drop wise to the reaction mixture,
5.2 Hz), 7.80 (2H, d, Jꢄ8.8 Hz). 13C-NMR (C5D5N) d: 14.3, 20.2, 20.5,
20.7, 22.9, 26.3, 29.5, 29.56, 29.59, 32.0, 55.4 (GlcN-2), 62.5 (GlcN-6),
which was stirred for 20 h at room temperature. After the reaction, the reac- 68.3 (Glc-6), 68.8 (OCH2), 69.6 (GlcN-4), 71.4 (GlcN-3), 72.5 (GlcN-5),
tion mixture was poured into ice water, which was extracted with diethyl 74.8 (OBn), 75.1 (OBn), 75.4 (OBn), 78.2 (Glc-4), 78.3 (Glc-5), 80.9 (Glc-
ether. The organic layer was successively washed with small amount of 2), 86.7 (Glc-3), 87.7 (Glc-1), 98.7 (GlcN-1), 115.7 (2C), 123.9 (2C), 127.8,
distilled water, a saturated aqueous solution of sodium thiosulfate, and
127.9 (4C), 128.0, 128.1 (3C), 128.3 (3C), 128.7 (7C), 131.7, 134.7 (2C),
135.3 (2C), 138.8, 139.2, 139.3, 159.9, 169.8, 170.4, 170.6. IR (CHCl3)
brine, dried over magnesium sulfate, and condensed in vacuo. The residue
was purified by column chromatography on silica gel (n-hexane : ethyl ac- n: 2930, 2856, 1747, 1720, 1593, 1495, 1387, 1366 cmꢀ1. HR-MS m/z:
etateꢄ30 : 1) to afford compound 10a (2.84 g, 71 %). [a]Dꢄꢀ12.1° (cꢄ 1110.4282 (Calcd for C61H69NO15SNa: 1110.4286).
1
1.25, CHCl3). H-NMR (C5D5N) d: 0.83 (3H, t, Jꢄ7.0 Hz), 1.20 (8H, m),
p-Octyloxyphenyl 3,4,6-Tri-O-acetyl-2-N-phthaloyl-
b(1—6)-D-glucos-
b-D-glucopyranoside (11b) A solution
1.38 (2H, m), 1.71 (2H, quint., Jꢄ6.5 Hz), 3.46 (1H, dd, Jꢄ5.0, 10.5 Hz, H- aminyl-1-thio-2,3,4-tri-O-benzoyl-
6), 3.75 (2H, br d, Jꢄ9.0 Hz, H-5 and H-6), 3.83 (1H, t, Jꢄ9.0 Hz, H-2),
3.88, 3.90 (each 1H, q, AB type, Jꢄ6.5 Hz, OCH2), 3.93 (1H, t, Jꢄ9.0 Hz,
of triphenylphosphine (66.1 mg, 0.256mmol) in carbon tetrachloride (1.0 ml)
was added to a solution of a mixture of 6c and 6cꢃ (29.2 mg, 0.026 mmol)
H-3), 3.98 (1H, t, Jꢄ9.0 Hz, H-4), 4.52 (1H, d, Jꢄ10.5 Hz, OBn), 4.87 (1H, in acetonitrile (2.0 ml), which was stirred for 2 h under refluxing condi-
d, Jꢄ10.5 Hz, OBn), 4.97 (1H, d, Jꢄ11.0 Hz, OBn), 4.99 (1H, d, Jꢄ11.0 Hz,
OBn), 5.02 (1H, d, Jꢄ11.0 Hz, OBn), 5.05 (1H, d, Jꢄ9.0 Hz, H-1), 5.14
tion. After the reaction, the reaction mixture was poured into a saturated
aqueous solution of sodium bicarbonate and extracted with ethyl acetate.
(1H, d, Jꢄ11.0 Hz, OBn), 7.06 (2H, d, Jꢄ8.8 Hz), 7.07 (2H, m), 7.24—7.42 The organic layer was extracted with ethyl acetate, washed with brine,
(18H, m), 7.45 (2H, br d, Jꢄ8.0 Hz), 7.63 (2H, br d, Jꢄ8.0 Hz), 7.75 (6H,
dried over magnesium sulfate, and evaporated. The residue was purified by
br d, Jꢄ8.0 Hz), 7.98 (2H, d, Jꢄ8.0 Hz). 13C-NMR (C5D5N) d: 14.2, 22.9, preparative silica gel thin layer chromatography (n-hexane : ethyl acetateꢄ
26.3, 29.5 (2C), 29.6, 32.0, 63.3 (C-6), 68.3 (OCH2), 75.0 (OBn), 75.2 1 : 1) to afford 11b (24.3 mg, 84%). [a]Dꢄꢀ6.7° (cꢄ0.80, CHCl3).
(OBn), 75.7 (OBn), 78.5 (C-4), 79.2 (C-5), 81.4 (C-2), 86.9 (Ph3C-), 87.1
1H-NMR (C5D5N) d: 0.84 (3H, t, Jꢄ7.0 Hz), 1.22 (8H, m), 1.41 (2H, m),
(C-3), 88.4 (C-1), 115.7 (2C), 124.4, 127.5 (2C), 127.88, 127.91, 128.0, 1.75 (2H, quint., Jꢄ6.6 Hz), 1.83, 1.98, 2.03 (each 3H, s, 3ꢅAc), 3.99 (2H,
128.1 (3C), 128.37 (9C), 128.40 (3C), 128.6 (3C), 128.7 (4C), 129.3 (6C), t, Jꢄ6.6 Hz, OCH2), 4.05 (1H, dd, Jꢄ6.0, 11.3 Hz, Glc-6), 4.13 (1H, ddd,
138.7, 139.3, 139.4, 144.7 (2C), 159.9. IR (CHCl3) n: 3065, 2930, 2858, Jꢄ2.5, 4.8, 10.0 Hz, GlcN-5), 4.35 (1H, dd, Jꢄ2.5, 12.2 Hz, GlcN-6), 4.43
1593, 1493, 1470, 1450 cmꢀ1
C60H64O6SNa: 935.4321).
p-Octyloxyphenyl 2,3,4-Tri-O-benzoyl-6-O-trityl-1-thio-b-D-glucopy-
ranoside (10b) Benzoyl chloride (34 ml, 0.29 mmol) and N,N-dimethyl-4-
aminopyridine (0.1 mg) were added to a solution of compound 9 (46.7 mg,
0.073 mmol) in pyridine (2.0 ml) and the mixture was stirred at 50 °C for 6 h.
.
HR-MS m/z: 935.4317 (Calcd for
(1H, dd, Jꢄ2.0, 11.3 Hz, Glc-6), 4.47 (1H, ddd, Jꢄ2.0, 6.0, 9.5 Hz, Glc-5),
4.56 (1H, dd, Jꢄ4.8, 12.2 Hz, GlcN-6), 4.93 (1H, dd, Jꢄ8.5, 10.8 Hz, GlcN-
2), 5.38 (1H, d, Jꢄ9.5 Hz, Glc-1), 5.56 (1H, dd, Jꢄ9.3, 10.0 Hz, GlcN-4),
5.80, 5.81 (each 1H, t, Jꢄ9.5 Hz, Glc-2 and 4), 6.01 (1H, d, Jꢄ8.5 Hz,
GlcN-1), 6.33 (1H, dd, Jꢄ9.3, 10.8 Hz, GlcN-3), 6.36 (1H, t, Jꢄ9.5 Hz, Glc-
3), 7.06 (2H, br t, Jꢄ7.5 Hz), 7.15 (2H, d, Jꢄ9.0 Hz), 7.17—7.30 (5H, m),
After removing the organic solvent in vacuo, the residue was extracted with 7.36 (1H, tt, Jꢄ1.5, 7.3 Hz), 7.39 (1H, tt, Jꢄ1.5, 7.3 Hz), 7.54 (2H, dd, Jꢄ
ethyl acetate. The organic layer was washed with brine, dried over magne- 3.1, 5.4 Hz), 7.73 (2H, d, Jꢄ8.0 Hz), 7.82—7.90 (6H, m), 8.10 (2H, dt, Jꢄ
sium sulfate, and evaporated. The residue was purified by silica gel column 1.5, 7.3 Hz). 13C-NMR (C5D5N) d: 14.3, 20.2, 20.4, 20.6, 22.9, 26.3, 29.48,
chromatography (n-hexane : ethyl acetateꢄ8 : 1) to afford 10b (53.2 mg,
29.53, 29.59, 32.0, 55.4 (GlcN-2), 62.4 (GlcN-6), 68.3 (OCH2), 68.8 (Glc-

764
Vol. 58, No. 5
6), 69.5 (GlcN-4), 69.9 (Glc-4), 71.2 (Glc-2), 71.4 (GlcN-3), 72.4 (GlcN-5),
75.3 (Glc-3), 77.5 (Glc-5), 85.9 (Glc-1), 98.9 (GlcN-1), 115.6 (2C), 121.7,
128.7 (3C), 128.8 (3C), 128.9 (3C), 129.3, 129.4, 129.87 (3C), 129.95 (3C),
130.1 (3C), 132.1, 133.5, 133.7 (2C), 134.6 (2C), 136.6 (2C), 160.4, 165.37,
165.40, 166.1, 169.8, 170.4, 170.5. IR (CHCl3) n: 1738, 1722, 1595, 1495,
1389, 1367, 1281, 1259, 1109, 1092 cmꢀ1. HR-MS m/z: 1152.3667 (Calcd
for C61H63NO18SNa: 1152.3664).
Methyl [(3,4,6-Tri-O-acetyl-2-N-phthaloyl-D-glucosaminyl)-b(1—6)-
2,3,4-tri-O-benzyl-D-glucopyranosyl]-b(1—6)-2,3,4-tri-O-acetyl-b-D-glu-
copyranoside (13a) N-Iodosuccinimide (15.2 mg, 0.068 mmol) and a quite
small amount of triflic acid (1 drop with a capillary) were added to a suspen-
sion of 11a (29.4 mg, 0.027 mmol), methyl 2,3,4-tri-O-benzyl-a-D-glucopy-
1074 cmꢀ1. HR-MS m/z: 1336.5098 (Calcd for C75H79NO20SNa: 1336.5093).
Methyl [(3,4,6-Tri-O-acetyl-2-N-phthaloyl-D-glucosaminyl)-b(1—6)-
2,3,4-tri-O-benzoyl-D-glucopyranosyl]-b(1—6)-2,3,4-tri-O-acetyl-b-
D-glucopyranoside (13b) N-Iodosuccinimide (12.0 mg, 0.053 mmol) and a
quite small amount of triflic acid (1 drop with a capillary) were added to a
suspension of 11b (24.3 mg, 0.022 mmol), methyl 2,3,4-tri-O-benzyl-a-D-
glucopyranoside (12) (10.0 mg, 0.022 mmol), and molecular sieves 4A (MS
4A) (150 mg) in dichloromethane (3 ml) at ꢀ50 °C. After stirring the mix-
ture for 25 min while keeping the temperature, the reaction mixture was
filtered through Hyflo super® which was washed with ethyl acetate. The
filtrate was diluted with an aqueous solution of sodium bicarbonate and
sodium thiosulfate, and extracted with ethyl acetate. The organic layer was
ranoside (12) (12.7 mg, 0.027 mmol), and molecular sieves 4A (MS 4A) washed with brine, dried over magnesium sulfate, and evaporated. The
(150 mg) in dichloromethane (3 ml) at ꢀ50 °C. After stirring the mixture for residue was purified by preparative silica gel thin layer chromatography (n-
1 h while keeping the temperature, the reaction mixture was filtered through hexane/ethyl acetateꢄ1 : 1) to afford 13b (22.3 mg, 76%). [a]Dꢄꢂ3.1° (cꢄ
Hyflo super® which was washed with ethyl acetate. The filtrate was diluted 0.78, CHCl3). 1H-NMR (C5D5N) d: 1.78, 1.98, 2.06 (each 3H, s, OAc), 3.35
with an aqueous solution of sodium bicarbonate and sodium thiosulfate, and
(3H, s, OMe), 3.66 (1H, dd, Jꢄ3.5, 9.5 Hz, a-Glc-2), 3.77 (1H, t, Jꢄ9.0 or
extracted with ethyl acetate. The organic layer was washed with brine, dried 9.5 Hz, a-Glc-4), 3.93—4.00 (2H, m, a-Glc-5 and 6), 4.11—4.23 (3H, m,
over magnesium sulfate, and evaporated. The residue was purified by prepar- a-Glc-3, GlcN-5, b-Glc-6), 4.36—4.47 (4H, m, b-Glc-5, b-Glc-6, a-Glc-6,
ative silica gel thin layer chromatography (n-hexane/ethyl acetateꢄ3 : 2) to
afford 13a (a mixture of a- and b-isomers, a : bꢄ1 : 2.5) (17.9 mg, 50%).
GlcN-6), 4.59 (1H, dd, Jꢄ4.8, 12.5 Hz, GlcN-6), 4.67 (1H, d, Jꢄ11.3 Hz,
OBn), 4.72 (2H, s, OBn), 4.79 (1H, d, Jꢄ11.3 Hz, OBn), 4.83 (1H, d, Jꢄ
b-Isomer: [a]Dꢄꢂ15.0° (cꢄ0.44, CHCl3). 1H-NMR (C5D5N) d: 1.81, 11.4 Hz, OBn), 4.89 (1H, dd, Jꢄ8.4, 10.5 Hz, GlcN-2), 4.92 (1H, d, Jꢄ3.5
2.00, 2.01 (each 3H, s, OAc), 3.44 (3H, s, OMe), 3.57 (1H, dd, Jꢄ7.8, Hz, a-Glc-1), 5.04 (1H, d, Jꢄ11.4 Hz, OBn), 5.22 (1H, d, Jꢄ7.7 Hz, b-Glc-
9.0 Hz, b-Glc-2), 3.61 (1H, dd, Jꢄ8.5, 9.0 Hz, b-Glc-4), 3.67 (1H, ddd, Jꢄ 1), 5.54 (1H, dd, Jꢄ9.0, 10.0 Hz, GlcN-4), 5.90 (1H, t, Jꢄ9.5 Hz, b-Glc-4),
1.5, 4.7, 9.9 Hz, b-Glc-5), 3.78 (1H, t, Jꢄ9.0 Hz, b-Glc-3), 3.84 (1H, Jꢄ3.5, 5.96 (1H, dd, Jꢄ7.7, 9.5 Hz, b-Glc-2), 6.00 (1H, d, Jꢄ8.4 Hz, GlcN-1), 6.34
9.2 Hz, MeO-Glc-2), 3.87 (1H, Jꢄ9.2, 9.8 Hz, MeO-Glc-4), 3.87 (1H, Jꢄ (1H, t, Jꢄ9.5 Hz, b-Glc-3), 6.34 (1H, dd, Jꢄ9.5, 10.5 Hz, GlcN-3), 7.06
3.5, 10.0 Hz, MeO-Glc-6), 4.02 (1H, ddd, Jꢄ1.5, 3.5, 9.8 Hz, MeO-Glc-5),
(2H, br t, Jꢄ7.5 Hz), 7.16—7.47 (22H, m), 7.55 (2H, dd, Jꢄ3.0, 5.5 Hz),
4.04 (1H, dd, Jꢄ4.7, 11.2 Hz, b-Glc-6), 4.17 (1H, ddd, Jꢄ2.4, 4.5, 10.2 Hz, 7.86—7.93 (6H, m), 8.08 (2H, dt, Jꢄ1.5, 7.5 Hz). 13C-NMR (C5D5N) d:
GlcN-5), 4.30 (1H, t, Jꢄ9.2 Hz, MeO-Glc-3), 4.37 (1H, dd, Jꢄ1.5, 11.2 Hz, 20.2, 20.4, 20.7, 55.1 (OMe), 55.4 (GlcN-2), 62.4 (GlcN-6), 67.9 (b-Glc-6),
b-Glc-6), 4.41 (1H, dd, Jꢄ1.5, 10.0 Hz, MeO-Glc-6), 4.43 (1H, dd, Jꢄ2.4, 68.6 (a-Glc-6), 69.6 (GlcN-4), 70.1 (b-Glc-4), 70.3 (a-Glc-5), 71.2 (GlcN-
12.2 Hz, GlcN-6), 4.53 (1H, d, Jꢄ11.0 Hz, OBn), 4.62 (1H, dd, Jꢄ4.6, 3), 72.4 (GlcN-5), 72.8 (b-Glc-2 and OBn), 74.0 (b-Glc-3, 5), 74.7 (OBn),
12.3 Hz, GlcN-6), 4.64 (1H, d, Jꢄ7.8 Hz, b-Glc-1), 4.73 (1H, d, Jꢄ11.0 Hz, 75.3 (OBn), 78.0 (a-Glc-4), 81.0 (a-Glc-2), 82.2 (a-Glc-3), 98.1 (a-Glc-1),
OBn), 4.83 (5H, br d, Jꢄ11.0 Hz, OBn), 4.91 (1H, dd, Jꢄ8.5, 10.8 Hz, 98.6 (GlcN-1), 101.4 (b-Glc-1), 127.7, 127.84, 127.87 (3C), 127.9, 128.08
GlcN-2), 4.93 (1H, d, Jꢄ11.0 Hz, OBn), 4.99, 5.00 (each 1H, d, Jꢄ11.0 Hz, (3C), 128.13 (3C), 128.6 (3C), 128.7 (8C), 128.8 (2C), 128.9 (2C), 129.36,
OBn), 5.05 (1H, d, Jꢄ3.5 Hz, MeO-Glc-1), 5.14, 5.18 (each 1H, d, Jꢄ11.0 129.41, 129.8 (2C), 129.9, 129.98 (2C), 130.01 (2C), 133.56, 133.61, 133.7,
Hz, OBn), 5.58 (1H, dd, Jꢄ9.2, 10.2 Hz, GlcN-4), 5.97 (1H, d, Jꢄ8.5 Hz, 134.7 (2C), 139.31, 139.35, 139.7, 165.5 (2C), 166.1, 169.8, 170.4, 170.5.
GlcN-1), 6.38 (1H, dd, Jꢄ9.2, 10.8 Hz, GlcN-3), 7.22—7.43 (25H, m),
IR (CHCl3) n: 3065, 1738, 1722, 1603, 1452, 1389, 1367, 1281, 1261 cmꢀ1
.
7.45—7.53 (9H, m). 13C-NMR (C5D5N) d: 20.2, 20.5, 20.7, 55.2 (OMe), HR-MS m/z: 1378.4469 (Calcd for C75H73NO23Na: 1378.4471).
55.4 (GlcN-2), 62.4 (GlcN-6), 68.6 (2C) (MeO-Glc-6 and b-Glc-6), 69.6
(GlcN-4), 70.6 (MeO-Glc-5), 71.2 (GlcN-3), 72.4 (GlcN-5), 72.8 (OBn),
Acknowledgements We are grateful for the support of a Grant-in-Aid
74.7 (2C) and 74.9 (2C) (3ꢅOBn and b-Glc-4), 75.3 and 75.5 (2ꢅOBn), (No. 20590022) from the Ministry of Education, Culture, Sports, Science
78.3 and 78.5 (b-Glc-5 and MeO-Glc-4), 81.1 (MeO-Glc-2), 82.3 (MeO- and Technology, Japan.
Glc-3), 82.6 (b-Glc-2), 84.8 (b-Glc-3), 99.2 (MeO-Glc-1), 98.7 (GlcN-1),
References
104.0 (b-Glc-1), 127.77 (3C), 127.83, 128.0 (9C), 128.1 (8C), 128.2 (2C),
1) Kahne D., Walker S., Chen Y., van Engen D., J. Am. Chem. Soc., 111,
128.62 (2C), 128.66 (2C), 128.68 (2C), 128.70 (2C), 128.73 (2C), 128.74
6881—6882 (1989).
(2C), 131.7, 134.8 (2C), 138.8, 139.3 (2C), 139.45, 139.48, 139.8, 169.8,
2) Raghavan S., Kahne D., J. Am. Chem. Soc., 115, 1580—1581 (1993).
170.4, 170.6. IR (CHCl3) n: 1749, 1720, 1387, 1366, 1159, 1086, 1072
3) Kajimoto T., Ishioka Y., Katoh T., Node M., Bioorg. Med. Chem. Lett.,
cmꢀ1. HR-MS m/z: 1336.5096 (Calcd for C75H79NO20SNa: 1336.5093).
16, 5736—5739 (2006).
a-Isomer: [a]Dꢄꢂ41.8° (cꢄ0.20, CHCl3). 1H-NMR (C5D5N) d: 1.82,
4) Kajimoto T., Ishioka Y., Katoh T., Node M., J. Carbohydr. Chem., 26,
2.00, 2.04 (each 3H, s, Ac), 3.41 (3H, s, OMe), 3.58 (1H, dd, Jꢄ3.3, 9.5 Hz,
a-Glc-2), 3.59 (1H, t, Jꢄ9.5 Hz, a-Glc-4), 3.66 (1H, dd, Jꢄ3.5, 9.5 Hz,
MeO-Glc-2), 3.77 (1H, br d, Jꢄ11.5 Hz, a-Glc-6), 3.92 (1H, br dd, Jꢄ4.0,
10.0 Hz, MeO-Glc-5), 3.95 (1H, dd, Jꢄ4.0, 11.0 Hz, MeO-Glc-6), 3.96 (1H,
t, Jꢄ10.0 Hz, MeO-Glc-4), 4.02 (1H, dd, Jꢄ3.8, 11.5 Hz, a-Glc-6), 4.10
(1H, ddd, Jꢄ1.0, 3.0, 9.5 Hz, a-Glc-5), 4.16 (1H, ddd, Jꢄ2.5, 4.5, 10.5 Hz,
GlcN-5), 4.22 (1H, t, Jꢄ9.5 Hz, a-Glc-3), 4.23 (1H, dd, Jꢄ9.5, 10.0 Hz,
MeO-Glc-3), 4.40 (1H, dd, Jꢄ2.5, 12.3 Hz, GlcN-6), 4.41 (1H, dd, Jꢄ1.5,
11.0 Hz, MeO-Glc-6), 4.48 (1H, Jꢄ11.0 Hz, OBn), 4.62 (1H, d, Jꢄ11.0 Hz,
OBn), 4.63 (1H, dd, Jꢄ4.5, 12.3 Hz, GlcN-6), 4.68, 4.73, 4.74, 4.75, 4.83
(each 1H, d, Jꢄ11.0 Hz, OBn), 4.91 (2H, d, Jꢄ11.0 Hz, OBn), 4.91 (1H, dd,
Jꢄ8.5, 10.5 Hz, GlcN-2), 4.98 (1H, d, Jꢄ3.5 Hz, MeO-Glc-1), 5.03, 5.10,
5.12 (each 1H, d, Jꢄ11.0 Hz, OBn), 5.12 (1H, d, Jꢄ3.3 Hz, a-Glc-1), 5.60
(1H, dd, Jꢄ9.0, 10.5 Hz, GlcN-4), 5.93 (1H, d, Jꢄ8.5 Hz, GlcN-1), 6.41
(1H, dd, Jꢄ9.0, 10.5 Hz, GlcN-3), 7.22—7.40 (22H, m), 7.43—7.52 (10H,
m), 7.78 (2H, dd, Jꢄ3.2, 5.3 Hz). 13C-NMR (C5D5N) d: 20.2, 20.4, 20.6,
55.1 (OMe), 55.4 (GlcN-2), 62.3 (GlcN-6), 66.2 (a-Glc-6), 68.9 (MeO-Glc-
6), 69.5 (GlcN-4), 70.3 (a-Glc-5), 70.9 (MeO-Glc-5), 71.2 (GlcN-3), 72.2
(OBn), 72.4 (GlcN-5), 72.8, 74.8, 75.0, 75.1, 75.5 (5ꢅOBn), 78.1 and 78.2
(MeO-Glc-4, a-Glc-4), 80.8 (MeO-Glc-2), 81.1 (a-Glc-2), 81.7 (a-Glc-3),
82.4 (MeO-Glc-3), 97.1 (a-Glc-1), 98.2 (MeO-Glc-1), 98.9 (GlcN-1),
127.6, 127.7, 127.82, 127.86, 127.89 (3C), 127.95 (3C), 127.98 (3C), 128.05
(3C), 128.08 (3C), 128.2 (2C), 128.56 (3C), 128.62 (4C), 128.68 (3C),
128.71 (3C), 128.74 (3C), 131.7, 138.9, 139.2 (2C), 139.4, 139.6, 139.7,
169.8, 170.5, 170.6. IR (CHCl3) n: 1747, 1720, 1387, 1366, 1163, 1084,
469—495 (2007).
5) Nishide K., Ohsugi S., Shiraki H., Tamakita H., Node M., Org. Lett.,
3, 3121—3124 (2001).
6) Node M., Kumar K., Nishide K., Ohsugi S., Miyamoto T., Tetrahedron
Lett., 42, 9207—9210 (2001).
7) Nishide K., Ohsugi S., Fudesaka M., Kodama S., Node M., Tetrahe-
dron Lett., 43, 5177—5179 (2002).
8) Nishide K., Miyamoto T., Kumar K., Ohsugi S., Node M., Tetrahedron
Lett., 43, 8569—8573 (2002).
9) Ohsugi S., Nishide K., Node M., Tetrahedron, 59, 1859—1871 (2003).
10) Ohsugi S., Nishide K., Oono K., Okuyama K., Fudesaka M., Kodama
S., Node M., Tetrahedron, 59, 8393—8398 (2003).
11) Nishide K., Ohsugi S., Miyamoto T., Kumar K., Node M., Monatsh.
Chem., 135, 189—200 (2004).
12) Nishide K., Pranab K. P., Matoba M., Shanmugasundaram K., Node
M., Green Chem., 6, 142—146 (2004).
13) Pranab K. P., Nishide K., Fuji K., Node M., Synthesis, 2004, 1003—
1006 (2004).
14) Matoba M., Kajimoto T., Nishide K., Node M., Chem. Pharm. Bull.,
54, 141—146 (2006).
15) Node M., Kajimoto T., Heteroatom Chem., 18, 572—583 (2007).
16) Matoba M., Kajimoto T., Node M., Synlett, 2007, 1930—1934 (2007).
17) Matoba M., Kajimoto T., Node M., Syn. Comm., 38, 1194—1200
(2008).
18) Castrillón J. P. A., Szmant H., J. Org. Chem., 30, 1338—1339 (1965).