Synthesis of GD3-lactam: A potential ligand for the development of an anti-melanoma vaccine

Article abstract of DOI:10.1016/S0008-6215(02)00036-8

The novel sialyl donor methyl (ethyl 4,7,8,9-tetra-O-acetyl-5-N,N-diacetylamino-3,5-dideoxy-2-thio-3-thiophenyl- D-erythro-β-L-gluco-non-2-ulopyranosid)onate was used for glycosylation of a lactosyl acceptor to give the GM3-trisaccharide derivative in 83%

Full text of DOI:10.1016/S0008-6215(02)00036-8

Carbohydrate Research 337 (2002) 569–580
www.elsevier.com/locate/carres
Synthesis of GD3-lactam: a potential ligand for the development
of an anti-melanoma vaccine
Nafizal Hossain,† Amparo Zapata,‡ Mikael Wilstermann,§ Ulf J. Nilsson,*
Go¨ran Magnusson¶
Center for Chemistry and Chemical Engineering, Organic and Bioorganic Chemistry, Lund Uni6ersity, PO Box 124, SE-221 00 Lund, Sweden
Received 14 August 2001; accepted 6 February 2002
Abstract
The novel sialyl donor methyl (ethyl 4,7,8,9-tetra-O-acetyl-5-N,N-diacetylamino-3,5-dideoxy-2-thio-3-thiophenyl-
D
-erythro-b-L-
gluco-non-2-ulopyranosid)onate was used for glycosylation of a lactosyl acceptor to give the GM3-trisaccharide derivative in 83%
yield. Introduction of an azido group at C-9%% of the GM3-trisaccharide derivative, transformation into a glycosyl acceptor, and
sialylation with the above mentioned novel sialyl donor gave a GD3-trisaccharide in 50% yield. Reduction of the azido group gave
the corresponding amine, which underwent spontaneous lactamization to the GD3-[1%%%–9%%]-lactam in an overall yield of 86%.
Removal of protecting groups of over five steps, followed by per-O-acetylation gave an acetylated GD3-[1%%%–9%%]-lactam TMSEt
glycoside in 27% overall yield. The acetylated GD3-[1%%%–9%%]-lactam TMSEt glycoside is suitable for glycosylation of linker-arms
and the resulting linker-glycosides are planned to be coupled to carrier proteins, thus providing immunogens for trial vaccinations
against malignant melanoma. © 2002 Elsevier Science Ltd. All rights reserved.
Keywords: Melanoma; Antigen; GD3; GD3-lactam; Glycosylation
self.6 It was recently reported that immunization of
melanoma patients with a GD3-lactone:KLH neoglyco-
1. Introduction
conjugate induced a strong immune response towards
Gangliosides (sialic acid-containing glycosphin-
GD3 and GD3-lactone, while immunization with the
golipids) are well-known tumor-associated antigens.1–5
corresponding GD3:KLH conjugate did not.7 These
However, gangliosides having an intact sialic acid ter-
results further emphasize the relevance of ganglioside
minal unit are only weakly immunogenic, thus reducing
lactones as tumor immunogens. Lactones are unstable
their potential as vaccine candidates against cancer.4,5
and undergo easy hydrolysis back to the hydroxy acid
Since gangliosides are hydroxy-carboxylic acids, they
form lactones on treatment with acids (such as acetic
form, which reduces the usefulness of ganglioside lac-
tones as immunogens. We introduced lactam analogs of
acid) and the lactones have been reported to be much
ganglioside lactones8 (Fig. 1) as hydrolytically stable
more immunogenic than the ganglioside saccharide it-
alternatives and found that these ganglioside lactams
are highly immunogenic; some of the anti-GM3-lactam
antibodies formed were shown to cross-react with the
corresponding ganglioside lactone,9 indicating a close
* Corresponding author. Tel.: +46-46-2228218; fax: +46-
46-2228209.
structural similarity between the lactone and the lac-
E-mail
address:
ulf.nilsson@bioorganic.lth.se
(U.J.
tam; the antibodies were capable of staining melanoma
cells, demonstrating the presence of lactones on the cell
surface.10 An ether analog of GM3-lactone has also
been reported11 as a hydrolytically stable lactone
analog (Fig. 1). We now wish to report our synthesis of
a lactam analog of one of the possible lactones of GD3
ganglioside, which is a tumor-associated antigen on
Nilsson).
† Present address: AstraZeneca R&D, Lund, SE-221 87
Lund, Sweden.
‡ Present address: Schenectady Pratteln GmbH, Switzer-
land.
§ Present address: AstraZeneca, Box 34, SE-221 00 Mo¨ln-
dal, Sweden.
¶ Deceased.
0008-6215/02/$ - see front matter © 2002 Elsevier Science Ltd. All rights reserved.
PII: S0008-6215(02)00036-8

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N. Hossain et al. / Carbohydrate Research 337 (2002) 569–580
Fig. 1. Synthetic analogs of ganglioside lactones. Examples of the aglycon residue R include alkyl, aryl, ceramide, linkers, and
linked protein.
human malignant melanoma cells.6 In order to create
the quite demanding a-(2“8)-bond between the two
terminal sialic acid units in GD3, novel sialic acid
donors were developed.12,13 The GD3-tetrasaccharide
has been synthesized by others.14
the yield of the desired a-(2“8)-linked bis-sialic acid
was rather low (28%).12 Another attempt towards im-
proved sialyl donors includes the use of a phenoxy-thio-
carbonyl group at C-3.16
It was recently reported17 that the nitrogen atom of
the acetamido residue of sialic acid donors can undergo
alkylation by the strongly electrophilic reagents nor-
mally used for activation of the anomeric thioalkyl
group. To avoid N-alkylation, an extra N-acetyl group
was introduced, which reduced the nucleophilicity of
the amide nitrogen, and sialylations could be performed
in high yield. In a comparative study with different
sialic acid acceptors, the a-Neu5Ac-(2“8)-Neu5Ac
moiety was obtained in ꢀ60% yield, but the a,b-ratio
was low.18 Following the glycosylation step, the extra
N-acetyl group was easily removed by methanolic
sodium methoxide to furnish the intact sialic acid moi-
ety.17,18 We have reported a further elaboration on this
2. Results and discussion
Synthesis of a no6el sialyl donor.—Glycosylation with
N-acetyl-neuraminic acid donors (sialylation) is more
difficult than other glycosylations, especially when an-
other sialic acid moiety is used as acceptor. In order to
avoid losses of donor (via side reactions) and also to
improve the a,b-ratio in sialylations, donors were intro-
duced that carry a thiophenyl substituent at C-3.14b,15 It
is believed that the thiophenyl substituent decreases the
acidity of H-3 and also leads to the formation of a
reactive episulfonium intermediate that can only be
attacked by the acceptor molecule from the a-side of
the donor. The original donors were O-benzylated,14b,15
whereas two recent donors (1 and its derivative 2;
Scheme 1) carry O-acetyl protecting groups.12,13 In a
comparative study of 1 and traditional sialyl donors
that lack the thiophenyl group, we found that only 1
gave sialylated products in the form of pure a-gly-
cosides; the other donors gave a-glycosides contami-
nated by a small amount (4–6%) of the corresponding
b-glycosides.12 Although donor 1 had the power to
sialylate the sterically hindered acceptor 18 (Scheme 2),
Scheme 1. (a) MePhSO3H, 55 °C, 30 h.

N. Hossain et al. / Carbohydrate Research 337 (2002) 569–580
571
,
Scheme 2. (a) AgOTf, MeSBr, MS 3 A, MeCN, CH2Cl2, −45 °C, 3 h. (b) Ac2O, pyridine.
Synthesis of the GD3-lactam.—The GM3-trisaccha-
ride 12 (Scheme 2) was treated with Ph3SnH–AIBN to
remove the auxiliary thiophenyl group, which gave 20
(75%; Scheme 3). Compound 20 was de-N- and O-
acetylated by treatment with MeONa–MeOH to give
the tetraol 21 (93%). Regioselective 9-O-tosylation of
21 provided the tosylate 22 (91%) and treatment of 22
theme and introduced the donor 2, carrying both a
thiophenyl group and an extra acetyl group on the
nitrogen atom13 (Scheme 1).
The preparation of 2 was performed according to the
procedure used for N-acetylation of traditional sialyl
donors.17–19 The known12 sialyl donor 1 was dissolved
in isopropenyl acetate, a catalytic amount of p-toluene-
sulfonic acid was added, and the mixture was stirred at
55 °C for 30 h. Residual isopropenyl acetate was then
removed, which gave pure 2 in 97% yield.
Sialylations with the no6el donor 2.—The efficiency of
2 as a sialyl donor was investigated by reaction with a
series of glycosyl acceptors (3,12 5,12 7,12 9,8b 11,12 14,12
16,8c 18,12b; Scheme 2), having different protecting-
group patterns. After some experimentation, it was
found that activation of 2 with AgOTf–methylsulfenyl
bromide, in the presence of the acceptor and with
MeCN–CH2Cl2 as the solvent, furnished the desired
a-sialylated compounds 4, 6, 8, 10, 12, 15, 17, and 19 in
39–96% yield after chromatographic purification. In no
case was the corresponding b-glycoside observed (TLC
Scheme 3. (a) Ph3SnH, AIBN, toluene, 120 °C, 4 h. (b)
MeONa, MeOH, 22 °C, 3 h. (c) MePhSO2Cl, pyridine,
CH2Cl2, −78 °C, 48 h. (d) NaN3, 18-crown-6, DMF, 60 °C,
24 h. (e) BzCl, Et3N, CH2Cl2, −45 °C, 24 h.
1
and H NMR).

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N. Hossain et al. / Carbohydrate Research 337 (2002) 569–580
saccharide 32 (53%), suitable for transformation into
linker-arm saccharides for further coupling to protein.
The protein conjugates should be potentially useful
immunogens for trial vaccinations against malignant
melanoma.4,5
3. Experimental
General methods.—The structures of all new com-
pounds were determined by careful NMR analyses,
including 2D-methods such as COSY, TOCSY, HET-
COR, long-range HETCOR, and NOESY. NMR spec-
tra were recorded with a Bruker ARX 400 MHz
spectrometer. Melting points are uncorrected. Molecu-
lar sieves were activated by drying under vacuum.
Dichloromethane was dried and distilled from CaH2
,
Scheme 4. (a) AgOTf, MeSBr, MS 3 A, MeCN, CH2Cl2,
−45 °C, 3 h. (b) MeONa, MeOH, 22 °C, 3 h. (c) Ph3P, THF,
H2O, 40 °C, 24 h. (d) Ac2O, pyridine, DMAP, 22 °C, 10 h.
,
prior to use. MeCN was kept over 3 A molecular sieved
for a few days and distilled from CaH2 prior to use.
,
DMF was dried over 4 A molecular sieved and distilled
from P2O5. Dichloroethane was distilled from P2O5. Br2
was distilled from P2O5. MeSBr was prepared in 1,2-
dichloroethane to give a 2 M solution. Et3N was dis-
tilled prior to use. Optical rotations were measured with
a Perkin–Elmer 141 polarimeter. High-resolution FAB
mass spectra were obtained on a JEOL JMS SX 102
spectrometer. Concentrations were made using rotary
evaporation with bath temperature at or below 40 °C.
TLC was performed on Kieselgel 60 F254 plates (E.
Merck). Column chromatography was performed using
SiO2 (Matrex LC-gel, 60A, 35-70 MY, Grace).
Scheme 5. (a) Ph3SnH, AIBN, toluene, 120 °C, 5 h. (b)
MeONa, MeOH, 22 °C, 12 h. (c) H2, Pd–C, EtOH, 22 °C, 10
h. (d) Ac2O, pyridine, DMAP, 22 °C, 10 h.
with NaN3 furnished the 9-azido-9-deoxy derivative 23
(84%). Since the reactivity order of the hydroxyl groups
of sialic acids is HO-9ꢁHO-4\HO-8ꢁHO-7,12,14d
compound 23 could be regioselectively 4-O-benzoy-
lated, which gave 24 (84%). The diol 24 was regioselec-
Methyl (ethyl 4,7,8,9-tetra-O-acetyl-5-N,N-diacety-
lamino-3,5-dideoxy-3-phenylthio-2-thio-D-erythro-i-L-
gluco-non-2-ulopyranosid)onate (2).—To a mixture of
compound 112 (1.287 g, 2.0 mmol) and isopropenyl
acetate (10 mL) was added p-toluenesulfonic acid (19
mg). The mixture was stirred at 60 °C for 20 h, then
cooled to rt. Et3N (1 drop) was added and the mixture
was concentrated. The residue was chromatographed
(19:1“4:1 toluene–MeCN) to give 2 (1.33 g, 97%).
tively sialylated with donor
2
to furnish the
GD3-tetrasaccharide 25 in 50% yield (Scheme 4). (In
comparison, sialylation of the diol 24 with the donor 1
gave only 28% of the corresponding tetrasaccharide.)
De-O-acylation of 25 then gave the azidohexaol 26
(82%), which was treated with Ph3P to reduce the azido
group; the resulting amino compound underwent spon-
taneous ring closure to yield the lactam 27 (86%). In
order to simplify the purification, 27 was O-acetylated
to give 28 (99%), which to our surprise had also under-
gone N-acetylation; this is to the best of our knowledge
the first example of N-acetylation of an amide nitrogen
under O-acetylation conditions (Ac2O, pyridine). The
thiophenyl auxiliary group of 28 was removed by treat-
ment with Ph3SnH–AIBN (as in the preparation of 20)
to give 29 in 65% yield (Scheme 5). De-O-acetylation of
29 gave the hexaol lactam 30 (83%) and hydrogenolytic
removal of the O-benzyl groups furnished the GD3-tet-
rasaccharide lactam 31 (96%). Treatment of 31 with
Ac2O–pyridine yielded the O- (and N-) acetylated GD3
1
[h]2D3 +72° (c 1.0, CHCl3); H NMR (CDCl3): l 7.61–
7.17 (m, 10 H, Ar), 5.79 (dd, 1 H, J 9.8, 10.8 Hz, H-4),
5.30 (m, 1 H, H-8), 5.12 (dd, 1 H, J 1.8, 8.4 Hz, H-7),
4.83 (dd, 1 H, J 1.8, 10.6 Hz, H-6), 4.33 (dd, 1 H, J
10.6, 9.8 Hz, H-5), 4.27 (dd, 1 H, J 2.8, 12.6 Hz, H-9),
4.14 (dd, 1 H, J 4.9, 12.6 Hz, H-9%), 3.94 (s, 3 H,
COOCH3), 3.42 (d, 1 H, J 10.8 Hz, H-3), 2.98–2.76 (m,
2 H, SCH2CH3), 2.36, 2.28, 2.17, 2.11, 2.03, 1.86, (6s, 3
H each, Ac), 1.27 (t, 3 H, J 7.5 Hz, SCH2CH3); 13C
NMR (CDCl3): l 174.6, 174.3, 171.1, 170.6, 170.5,
170.4, 167.9, 137.9, 132.0, 129.5, 129.4, 128.7, 127.8,
125.7, 87.5, 72.3, 71.8, 68.9, 67.4, 62.1, 60.5, 57.5, 53.5,
28.5, 27.0, 23.8, 21.5, 21.4, 21.2, 21.0, 14.3; HRMS m/z
Calcd for C30H39O13NS2Na [M+Na] 708.1760. Found
708.1744.

N. Hossain et al. / Carbohydrate Research 337 (2002) 569–580
573
(Methyl 4,7,8,9-tetra-O-acetyl-5-N,N-diacetylamino-
3,5-dideoxy-3-phenylthio- -erythro-i- -gluco-non-2-
ulopyranosylonate)-(2“6)-1,2;3,4-di-O-isopropylidene-
(dd, 1 H, J 10.0, 3.7 Hz, H-3), 4.63 (d, 1 H, J 8.0 Hz,
H-1), 4.62 (dd, 1 H, J 2.4, 10.5 Hz, H-6%), 4.42 (dd, 1 H,
J 10.5, 9.6 Hz, H-5%), 4.03 (dd, 1 H, J 4.8, 12.6 Hz,
H-9%%), 3.95 (s, 3 H, COOCH3), 3.59 (s, 3 H, OMe), 3.06
(d, 1 H, J 11.0 Hz, H-3%), 2.37, 2.27, 2.23, 2.15, 2.06,
2.01, 1.88, 1.83 (8s, 3 H each, Ac); 13C NMR (CDCl3):
l 174.3, 174.0, 171.03, 170.99, 170.92, 170.88, 170.2,
170.1, 167.6, 166.2, 138.3, 133.6, 131.6, 130.23, 130.18,
129.5, 129.4, 128.8, 128.7, 127.4, 125.7, 102.2, 98.8,
72.9, 71.8, 70.9, 69.8, 68.1, 67.7, 67.0, 62.6, 62.4, 60.3,
57.4, 56.5, 53.3, 28.5, 27.5, 21.8, 21.6, 21.3, 21.2, 21.0,
20.9. (C-1%, 3JC-1%ꢀH-3%ax 6.0 Hz; cf. Refs. 12a, 21); HRMS
m/z Calcd for C46H55NNaO22S [M+Na] 1028.2834.
Found 1028.2849.
D
L
h- -galactopyranose (4).—Donor 2 (132 mg, 0.193
D
mmol), and acceptor 312 (42 mg, 0.161 mmol) were
dissolved in a mixture of MeCN (3 mL) and CH2Cl2
,
(1.5 mL) and powdered 3 A molecular sieves (250 mg)
were added. The reaction mixture was stirred at rt for 5
min under N2 and cooled to −45 °C. AgOTf (110 mg,
0.426 mmol) was dissolved in MeCN (1 mL) and the
solution was added to the reaction mixture. After 5
min, a 2 M solution of MeSBr in 1,2-dichloroethane20
(0.194 mL) was added over a period of 5 min. The
reaction mixture was stirred at −45 °C for 3 h. Diiso-
propyl amine (0.1 mL) was added and the reaction
mixture was stirred for 45 min at −45 °C. The temper-
ature was raised to 22 °C, the mixture was filtered, the
solid material was washed with MeCN, and the filtrate
was concentrated. The residue was chromatographed
(19:1“9:1 toluene–MeCN) to give pure 4 (100 mg,
Methyl (methyl 4,7,8,9-tetra-O-acetyl-5-N,N-diacetyl-
amino-3,5-dideoxy-3-phenylthio-
D-erythro-i-L-gluco-
non-2-ulopyranosylonate)-(2“3)-2,4,6-tri-O-acetyl-i-
D
-galactopyranoside (8).—Donor 2 (121 mg, 0.177
mmol), and acceptor 712 (41 mg, 0.147 mmol) were
dissolved in a mixture of MeCN (3 mL) and CH2Cl2
1
70%). [h]2D3 +8° (c 1.0, CHCl3); H NMR (CDCl3): l
(1.5 mL) and activated powdered 3 A molecular sieves
,
7.60–7.15 (m, 5 H, Ar), 5.88 (dd, 1 H, J 8.7, 9.7 Hz,
H-4%), 5.53 (d, 1 H, J 5.0 Hz, H-1), 5.33 (ddd, 1 H, J
3.0, 5.3, 7.6 Hz, H-8%), 5.17 (dd, 1 H, J 1.6, 10.2 Hz,
H-6%), 5.10 (dd, 1 H, J 1.6, 7.6 Hz, H-7%), 4.58 (dd, 1 H,
J 2.3, 7.9 Hz, H-3), 4.38 (t, 1 H, J 10.2 Hz, H-5%), 4.31
(dd, 1 H, J 5.0, 2.3 Hz, H-2), 4.25 (dd, 1 H, J 3.0, 12.4
Hz, H-9%), 4.20 (dd, 1 H, J 1.0, 7.9 Hz, H-4), 4.13 (dd,
1 H, J 5.3, 12.4 Hz, H-9%), 4.07–3.94 (m, 3 H, H-5,6),
3.86 (s, 3 H, COOCH3), 3.32 (d, 1 H, J 8.7 Hz, H-3%),
2.39, 2.27, 2.11, 2.08, 2.02, 1.96 (6s, 3 H each, Ac), 1.46,
1.44, 1.34, 1.32 (4s, 3 H each, Me); 13C NMR (CDCl3):
l 174.9, 174.1, 171.0, 170.4, 170.3, 170.1, 167.7, 133.5,
129.4, 128.2, 109.7, 109.0, 101.1, 96.7, 72.1, 71.6, 71.1,
71.0, 70.1, 69.3, 67.8, 67.5, 64.6, 62.2, 59.5, 57.3, 52.9,
28.4, 26.6, 26.44, 26.41, 25.5, 24.9, 21.4, 21.3, 21.2, 21.0;
(250 mg) were added. The mixture was treated essen-
tially as in the preparation of 4, using 0.177 mL of the
2 M MeSBr solution, AgOTf (100 mg, 0.388 mmol).
Workup and chromatographic purification (19:1“3:1
toluene–MeCN), followed by O-acetylation (Ac2O–
pyridine) and chromatography furnished 8 (90 mg,
1
65%). [h]2D3 +72° (c 1.0, CHCl3); H NMR (CDCl3): l
7.54–7.15 (m, 5 H, Ar), 5.75 (dd, 1 H, J 9.6, 10.9 Hz,
H-4%), 5.48 (ddd, 1 H, J 9.2, 2.6, 4.8 Hz, H-8%), 5.34 (dd,
1 H, J 3.8, 1.0 Hz, H-4), 5.23 (dd, 1 H, J 8.0, 10.0 Hz,
H-2), 5.19 (dd, 1 H, J 2.4, 9.2 Hz, H-7%), 4.87 (dd, 1 H,
J 10.0, 3.8 Hz, H-3), 4.61 (dd, 1 H, J 10.5, 2.4 Hz,
H-6%), 4.56 (d, 1 H, J 8.0 Hz, H-1), 4.41 (dd, 1 H, J 9.6,
10.5 Hz, H-5%), 4.32 (dd, 1 H, J 2.6, 12.6 Hz, H-9%), 4.15
(brd, 2 H, J 6.8 Hz, H-6.6%), 4.02 (dd, 1 H, J 4.8, 12.6
Hz, H-9%%), 3.99 (s, 3 H, COOCH3), 3.95 (m, 1 H, H-5),
3.57 (s, 3 H, OMe), 3.05 (d, 1 H, J 10.9 Hz, H-3%), 2.36,
2.26, 2.22, 2.19, 2.07, 2.05, 2.00, 1.86, 1.79 (9s, 3 H
each, Ac); 13C NMR (CDCl3): l 174.3, 174.0, 171.04,
171.00, 170.97, 170.91, 170.88, 170.20, 170.15, 167.6,
138.2, 131.5, 129.4, 128.7, 127.4, 125.7, 102.0, 98.8,
72.8, 71.8, 71.1, 70.8, 69.9, 68.1, 67.9, 67.0, 62.9, 62.4,
60.2, 57.3, 56.5, 53.4, 28.6, 27.5, 21.9, 21.6, 21.3, 21.21,
21.16, 21.0, 20.9; HRMS m/z Calcd for C41H53-
NNaO22S [M+Na] 966.2677. Found 966.2688.
3
(C-1%, JC-1%ꢀH-3%ax 4.9 Hz; cf. Refs. 12a, 21); HRMS m/z
Calcd for C40H53NNaO19S [M+Na] 906.2830. Found
906.2823.
Methyl (methyl 4,7,8,9-tetra-O-acetyl-5-N,N-diacetyl-
amino-3,5-dideoxy-3-phenylthio-
D-erythro-i-L-gluco-
non-2-ulopyranosylonate)-(2“3)-2,4-di-O-acetyl-6-O-
benzoyl-i- -galactopyranoside (6).—Donor 2 (110 mg,
D
0.161 mmol), and acceptor 512 (40 mg, 0.134 mmol)
were dissolved in a mixture of MeCN (3 mL) and
,
CH2Cl2 (1.5 mL) and powdered 3 A molecular sieves
(250 mg) were added. The mixture was treated essen-
tially as in the preparation of 4, using 0.161 mL of the
2 M MeSBr solution, AgOTf (91 mg, 0.354 mmol).
Workup and chromatographic purification (19:1“4:1
toluene–MeCN), followed by O-acetylation (Ac2O–
pyridine) and chromatography furnished 6 (52 mg,
2-(Trimethylsilyl)ethyl (methyl 4,7,8,9-tetra-O-acetyl-
5-N,N-diacetylamino-3,5-dideoxy-3-phenylthio-
thro-i- -gluco-non-2-ulopyranosylonate)-(2“3)-2-
azido-6-O-benzoyl-2-deoxy-i-
D-ery-
L
D
-galactopyranoside (10).
—Donor 2 (100 mg, 0.146 mmol) and acceptor 98b (30
mg, 0.073 mmol) were dissolved in a mixture of MeCN
(1 mL) and CH2Cl2 (0.7 mL) and activated powdered 3
1
39%). [h]2D3 +51° (c 1.0, CHCl3); H NMR (CDCl3): l
,
8.16–7.15 (m, 10 H, Ar), 5.75 (dd, 1 H, J 11.0, 9.6 Hz,
H-4%), 5.53–5.47 (m, 2 H, H-8%,4), 5.28 (dd, 1 H, J 8.0,
10.0 Hz, H-2), 5.18 (dd, 1 H, J 2.4, 9.2 Hz, H-7%), 4.92
A molecular sieves (200 mg) were added. The mixture
was treated essentially as in the preparation of 4, using
0.147 mL of the 2 M MeSBr solution, AgOTf (83 mg,

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N. Hossain et al. / Carbohydrate Research 337 (2002) 569–580
0.322 mmol). Workup and chromatographic purifica-
tion (19:1“4:1 toluene–MeCN) furnished 10 (50 mg,
66%). [h]2D3 +27° (c 0.46, CHCl3); 1H NMR (CDCl3): l
8.08–7.15 (m, 10 H, Ar), 5.92 (dd, 1 H, J 10.7, 10.0 Hz,
H-4%), 5.43 (ddd, 1 H, J 8.7, 2.8, 5.0 Hz, H-8%), 5.18 (dd,
1 H, J 1.9, 8.7 Hz, H-7%), 5.11 (dd, 1 H, J 1.9, 10.2 Hz,
H-6%), 4.48 (t, 1 H, J 10.0 Hz, H-5%), 3.95 (s, 3 H,
COOCH3), 3.45 (d, 1 H, J 10.8 Hz, H-3%), 2.39, 2.36,
2.29, 2.09, 2.07, 2.03 (6s, 3 H each, Ac), 1.12–0.96 (m,
2 H, CH2Si), −0.01 (s, 9 H, SiMe3); 13C NMR
(CDCl3): l 174.8, 174.0, 171.0, 170.5, 170.3, 167.9,
166.6, 136.0, 133.5, 131.9, 130.5, 130.1, 129.8, 129.5,
128.8, 128.7, 128.4, 101.0, 100.6, 75.8, 72.1, 70.4, 70.3,
68.7, 67.6, 67.5, 67.1, 64.1, 63.1, 62.4, 59.3, 57.0, 53.2,
28.5, 26.7, 21.4, 21.3, 21.2, 21.0, 18.5, −0.2. (C-1%,
3JC-1%ꢀH-3%ax 6.9 Hz; cf. Refs. 12a, 21); HRMS m/z Calcd
for C46H60N4NaO19SSi [M+Na] 1055.3239. Found
1055.3239. A sample of 10 (40 mg, 0.0387 mmol) was
treated with Ac2O–pyridine and the crude product was
purified by chromatography (19:1“4:1 toluene–Me-
CN) to give 2-(trimethylsilyl)ethyl (methyl 4,7,8,9-tetra-
O-acetyl-5-N,N-diacetylamino-3,5-dideoxy-3-phenyl-
mg). When 2 equiv of 2 and 1 equiv of 11 were used, 12
was obtained in 83% yield. H NMR (CDCl3): l 7.40–
1
7.10 (m, 35 H, Ar), 5.87 (dd, 1 H, J 9.7, 11.0 Hz, H-4%%),
5.52 (m, 1 H, H-8%%), 5.17 (dd, 1 H, J 2.2, 8.4 Hz, H-7%%),
5.12 (d, 1 H, J 11.2 Hz, CH2Ph), 5.04 (d, 1 H, J 11.1
Hz, CH2Ph), 4.91 (d, 1 H, J 11.0 Hz, CH2Ph), 4.79 (dd,
1 H, J 2.2, 10.4 Hz, H-6%%), 4.74 (d, 1 H, J 7.4 Hz, H-1%),
4.38 (d, 1 H, J 8.7 Hz, H-1), 4.24 (dd, 1 H, J 2.4, 12.9
Hz, H-9%%), 3.93 (s, 3 H, COOCH3), 3.30 (d, 1 H, J 11.0
Hz, H-3%%), 2.39, 2.28, 2.09, 1.96, 1.92, 1.77 (6s, 3 H
each, Ac), 1.03 (m, 2 H, CH2Si), 0.03 (s, 9 H, SiMe3);
13C NMR (CDCl3): l 174.4, 174.2, 170.9, 170.7, 170.6,
170.2, 168.0, 140.0, 139.7, 139.6, 139.2, 139.1, 139.0,
137.8, 131.8, 129.3, 128.7, 128.63, 128.6, 128.53, 128.48,
128.41, 128.36, 128.3, 127.93, 127.85, 127.83, 127.81,
127.73, 127.66, 127.6, 127.5, 127.4, 103.4, 103.1, 99.9,
83.3, 82.5, 80.0, 75.7, 75.6, 75.4, 75.3, 75.2, 75.0, 73.4,
73.3, 72.7, 71.9, 70.0, 69.6, 68.8, 68.5, 67.8, 67.2, 62.1,
60.3, 56.9, 53.2, 28.6, 27.3, 21.6, 21.2, 21.1, 21.0, 18.9,
3
-0.10. (C-1%%, JC-1%%ꢀH-3%%ax 6.1 Hz; cf. Refs. 12a, 21);
HRMS m/z Calcd for C87H103NNaO24SSi [M+Na]
1628.6257. Found 1628.6261.
thio-
D
-erythro-b-
L
-gluco-non-2-ulopyranosylonate)-
2-(Trimethylsilyl)ethyl (methyl 5-acetamido-4,7,8,9-
(2“3)-4-O-acetyl-2-azido-6-O-benzoyl-2-deoxy-b-
D
-
tetra-O-acetyl-3,5-dideoxy-3-phenylthio-
gluco - non - 2 - ulopyranosylonate) - (2“3) - (2,4,6 - tri - O-
benzyl - i - - galactopyranosyl) - (1“4) - 2,3,6 - tri - O-
benzyl-i- -glucopyranoside (13).—Compound 12 (20
D-erythro-i-L-
galactopyranoside (38 mg, 91%). [h]2D3 +28° (c 0.55,
1
CHCl3); H NMR (CDCl3): l 8.08–7.15 (m, 10 H, Ar),
D
5.85 (dd, 1 H, J 9.7, 10.9 Hz, H-4%), 5.51 (d, 1 H, J 3.4
Hz, H-4), 5.48 (m, 1 H, H-8%), 5.19 (dd, 1 H, J 2.0, 8.8
Hz, H-7%), 4.93 (dd, 1 H, J 10.1, 3.6 Hz, H-3), 4.74 (dd,
1 H, J 2.0, 10.3 Hz, H-6%), 4.44 (d, 1 H, J 8.2 Hz, H-1),
4.37 (t, 1 H, J 10.0 Hz, H-5%), 3.96 (s, 3 H, COOCH3),
3.33 (d, 1 H, J 11.0 Hz, H-3%), 2.36, 2.25, 2.11, 2.06,
2.04, 1.91, 1.89 (7s, 3 H each, Ac), 1.10 (m, 2 H,
CH2Si), 0.02 (s, 9 H, SiMe3); 13C NMR (CDCl3): l
174.5, 174.0, 171.1, 170.9, 170.64, 170.60, 170.5, 167.4,
166.3, 138.3, 138.2, 133.6, 132.9, 132.1, 132.0, 131.3,
130.19, 130.15, 129.5, 129.4, 128.8, 128.7, 127.8, 127.5,
125.7, 100.7, 98.9, 77.7, 73.6, 71.5, 71.0, 69.8, 68.6, 68.1,
67.4, 66.9, 63.5, 62.6, 62.4, 59.3, 57.0, 53.4, 28.5, 26.9,
21.7, 21.2, 21.1, 20.9, 18.6, −0.2; HRMS m/z Calcd for
C48H62N4NaO20SiS [M+Na] 1097.3345. Found
1097.3326.
D
mg, 0.012 mmol) was dissolved in MeOH (0.5 mL) and
1 M NaOMe in MeOH (0.009 mL) was added. The
mixture was left at 22 °C for 4 h and neutralized with
Duolite C26 (H+) resin. The resin was filtered off and
washed with MeOH. The filtrate was concentrated and
the residue was treated with Ac2O in pyridine to give 13
(17 mg, 87%) after chromatographic purification. The
physical properties of 13 were identical with those
reported.12b
2-(Trimethylsilyl)ethyl (methyl 4,7,8,9-tetra-O-acetyl-
5-N,N-diacetylamino-3,5-dideoxy-3-phenylthio-
thro-i- -gluco-non-2-ulopyranosylonate)-(2“3)-(2-
azido - 6 - O - benzyl - 2 - deoxy - i - - galactopyranosyl)-
D-ery-
L
D
(1“4)-2,3,6-tri-O-benzyl-i- -glucopyranoside (15).—
D
Donor 2 (80 mg, 0.116 mmol) and acceptor 1412 (80
2-(Trimethylsilyl)ethyl (methyl 4,7,8,9-tetra-O-acetyl-
mg, 0.097 mmol) were dissolved in a mixture of MeCN
,
5-N,N-diacetylamino-3,5-dideoxy-3-phenylthio-
thro-i- -gluco-non-2-ulopyranosylonate)-(2“3)-(2,4,6-
tri-O-benzyl-i- -galactopyranosyl)-(1“4)-2,3,6-tri-O-
D
-ery-
(2 mL) and CH2Cl2 (1 mL) and activated powdered 3 A
L
molecular sieves (200 mg) were added. The mixture was
treated essentially as in the preparation of 4, using
AgOTf (66 mg, 0.255 mmol) in MeCN (1 mL), 0.116
D
benzyl-i- -glucopyranoside (12).—Donor 2 (685.7 mg,
D
1.0 mmol) and acceptor 1112 (1.51 g, 1.536 mmol) were
mL of the 2 M MeSBr solution, and Pr2NH (0.1 mL).
i
dissolved in a mixture of MeCN (3 mL) and CH2Cl2
Workup and chromatographic purification (19:1“9:1
(1.5 mL) and activated powdered 3 A molecular sieves
toluene–acetone) furnished 15 (135 mg, 96%). [h]2D3+
,
1
(400 mg) were added. The mixture was treated essen-
tially as in the preparation of 4, using AgOTf (565 mg,
2.2 mmol) in MeCN (1 mL) and 1 mL of the 2 M
MeSBr solution. Workup and chromatographic purifi-
cation (19:1“9:1 toluene–MeCN) furnished 12 (1.1 g,
69%; yield based on donor 2) and recovered 11 (600
13° (c 1.0, CHCl3); H NMR (CDCl3): l 7.56–7.15 (m,
25 H, Ar), 5.95 (dd, 1 H, J 10.7, 9.9 Hz, H-4%%), 5.45
(ddd, 1 H, J 2.5, 5.5, 8.3 Hz, H-8%%), 5.18 (dd, 1 H, J 1.7,
8.3 Hz, H-7%%), 5.08 (dd, 1 H, J 1.7, 10.2 Hz, H-6%%), 5.01
(d, 1 H, J 11.0 Hz, CH2Ph), 4.93 (d, 1 H, J 10.9 Hz,
CH2Ph), 4.84 (d, 1 H, J 11.0 Hz, CH2Ph), 4.54 (d, 1 H,

N. Hossain et al. / Carbohydrate Research 337 (2002) 569–580
575
1
J 8.1 Hz, H-1%), 4.41 (d, 1 H, J 8.0 Hz, H-1), 4.28 (dd,
1 H, J 2.5, 12.6 Hz, H-9%%), 3.96 (s, 3 H, COOCH3), 3.44
(d, 1 H, J 10.7 Hz, H-3%%), 2.41, 2.31, 2.22, 2.20, 1.95,
1.77 (6s, 3 H each, Ac), 1.07 (m, 2 H, CH2Si), 0.05 (s,
9 H, SiMe3); 13C NMR (CDCl3): l 174.7, 174.0, 170.9,
170.49, 170.45, 170.0, 167.7, 139.7, 139.1, 139.0, 138.7,
136.4, 132.0, 129.7, 127.5, 128.72, 128.68, 128.54,
128.52, 128.48, 128.2, 128.13, 128.10, 128.04, 127.99,
127.95, 127.86, 127.8, 127.5, 125.8, 103.5, 100.91,
100.87, 83.4, 82.7, 76.2, 75.5, 75.4, 75.3, 73.74, 73.67,
73.0, 70.8, 70.4, 69.6, 69.04, 68.99, 67.8, 67.5, 67.2, 64.2,
62.4, 59.3, 57.1, 53.3, 28.5, 26.7, 21.9, 21.4, 21.1, 21.0,
19.0, −0.1. A sample of 15 was acetylated and the
crude product was purified by chromatography (19:1“
4:1 toluene–MeCN) to give 2-(trimethylsilyl)ethyl
(methyl 4,7,8,9-tetra-O-acetyl-5-N,N-diacetylamino-3,5-
CHCl3); H NMR (CDCl3): l 7.53–7.20 (m, 5 H, Ar),
5.78 (dd, 1 H, J 9.6, 10.9 Hz, H-4%%), 5.46 (m, 1 H, H-8%%),
5.07 (dd, 1 H, J 8.0, 9.9 Hz, H-2%), 4.84 (dd, 1 H, J 7.3,
9.0 Hz, H-2), 4.56 (d, 1 H, J 8.0 Hz, H-1%), 4.42 (d, 1 H,
J 7.3 Hz, H-1), 4.35 (dd, 1 H, J 2.5, 12.4 Hz, H-9%%), 4.09
(dd, 1 H, J 5.3, 11.9 Hz, H-5), 3.95 (s, 3 H, COOCH3),
3.31 (dd, 1 H, J 9.9, 11.9, Hz, H-5), 3.18 (d, 1 H, J 10.9
Hz, H-3%%), 2.35, 2.26, 2.19, 2.12, 2.09, 2.05, 2.04, 2.03,
2.01, 1.87 (10s, 3 H each, Ac), 0.09–0.83 (m, 2 H,
CH2Si), −0.01 (s, 9 H, SiMe3); 13C NMR (CDCl3): l
174.4, 173.9, 171.2, 171.0, 170.8, 170.6, 170.5, 170.3,
170.2, 169.9, 167.8, 136.8, 131.6, 129.6, 127.9, 101.4,
100.9, 99.5, 76.5, 74.9, 73.1, 72.4, 71.8, 71.4, 70.4, 70.1,
68.3, 68.26, 67.6, 67.2, 63.8, 63.7, 62.8, 59.9, 56.4, 53.4,
28.6, 27.4, 21.7, 21.5, 21.3, 21.24, 21.18, 21.1, 20.9, 18.4,
3
−0.1 (C-1%%, JC-1%%ꢀH-3%%ax 6.1 Hz; cf. Refs. 12a, 21);
dideoxy-3-phenylthio-
ranosylonate)-(2“3)-(2-azido-4-O-acetyl-6-O-benzyl-2-
D
-erythro-b-
L
-gluco-non-2-ulopy-
HRMS m/z Calcd for C52H73NNaO27SSi [M+Na]
1226.3757. Found 1226.3781. A sample of 17 was per-
O-acetylated with Ac2O–pyridine and the crude
product was chromatographed (9:1“3:1 toluene–
MeCN) to give 2-(trimethylsilyl)ethyl (methyl 4,7,
8,9-tetra-O-acetyl-5-N,N-diacetylamino-3,5-dideoxy-3-
deoxy-b- -galactopyranosyl)-(1“4)-2,3,6-tri-O-benzyl-
D
b-D
-glucopyranoside (110 mg 79%). [h]2D3 +20° (c 1.0,
1
CHCl3); H NMR (CDCl3): l 7.48–7.15 (m, 25 H, Ar),
5.89 (dd, 1 H, J 9.7, 10.9 Hz, H-4%%), 5.52 (ddd, 1 H, J
2.6, 5.4, 8.5 Hz, H-8%%), 5.45 (d, 1 H, J 3.6 Hz, H-4%) 5.19
(dd, 1 H, J 1.8, 8.5 Hz, H-7%%), 5.02 (d, 1 H, J 11.0 Hz,
CH2Ph), 4.88 (d, 1 H, J 11.4 Hz, CH2Ph), 4.78 (dd, 1 H,
J 1.9, 10.4 Hz, H-6%%), 4.62 (d, 1 H, J 12.0 Hz, CH2Ph),
4.44 (d, 1 H, J 7.8 Hz, H-1), 4.30 (dd,1 H, J 2.6, 12.6
Hz, H-9%%), 4.02 (s, 3 H, COOCH3), 3.44 (dd,1 H, J 7.9,
9.1 Hz, H-2), 3.37 (d,1 H, J 10.9 Hz, H-3%%), 2.37, 2.27,
2.18, 2.11, 2.05, 1.98, 1.87 (7s, 3 H each, Ac), 1.13–1.01
(m, 2 H, CH2Si), 0.06 (s, 9 H, SiMe3); 13C NMR
(CDCl3): l 174.4, 174.1, 171.0, 170.6, 170.5, 170.4,
170.3, 167.1, 139.7, 139.1, 139.0, 138.52, 138.46, 131.0,
129.5, 129.4, 128.74, 128.71, 128.67, 128.6, 128.5, 128.1,
128.0, 127.93, 127.91, 127.8, 127.6, 127.3, 125.8, 103.5,
100.7, 99.1, 83.3, 82.7, 75.4, 75.34, 75.29,
73.9, 73.60, 73.55, 72.1, 71.7, 69.8, 69.6, 68.6, 67.9,
67.8, 67.5, 67.0, 64.8, 62.5, 59.0, 57.0, 28.5, 27.0, 21.9,
phenylthio-
nate)-(2“3)-(2,4,6-tri-O-acetyl-b-
(1“4)-2,4-di-O-acetyl-b- -xylopyranoside (26 mg,
D
-erythro-b-
L
-gluco-non-2-ulopyranosylo-
D
-galactopyranosyl)-
D
97%). [h]2D3 +38° (c 0.55, CHCl3); 1H NMR (CDCl3): l
7.52–7.15 (m, 5 H, Ar), 5.73 (dd, J 5.8, 10.9 Hz, 1 H,
H-4%%), 5.54 (m, 1 H, H-8%%), 5.26 (dd, J 1.0, 3.7 Hz, 1 H,
H-4%), 4.84 (dd, 1 H, J 10.1, 3.7 Hz, H-3%), 4.67 (d, J 8.0
Hz, 1 H, H-1%), 4.60 (dd, J 10.6, 2.5 Hz, 1 H, H-6%%), 4.14
(dd, 1 H, J 5.1, 11.9 Hz, H-5), 3.98 (s, 3 H, COOCH3),
3.56 (m, 1 H, OCH2CH2Si); 3.35 (dd, 1 H, J 9.9, 11.9
Hz, H-5), 3.04 (d, 1 H, J 10.9 Hz, H-3%%), 2.35, 2.26,
2.22, 2.18, 2.08, 2.06, 2.05, 2.02, 1.87, 1.80 (10s, 3 H
each, Ac), 1.00–0.85 (m, 2 H, CH2Si), 0.01 (s, 9 H,
SiMe3); 13C NMR (CDCl3): l 174.3, 174.0, 171.12,
171.05, 170.99, 170.90, 170.86, 170.6, 170.4, 170.2,
169.8, 167.5, 138.3, 131.6, 129.5, 129.4, 128.7, 127.5,
101.8, 101.0, 98.7, 73.3, 72.6, 71.8, 71.3, 70.7, 69.8,
68.0, 67.72, 67.66, 67.3, 63.7, 63.0, 62.8, 60.1, 56.3, 53.5,
28.6, 27.5, 21.9, 21.4, 21.32, 21.26, 21.21, 21.19,
21.15, 21.0, 20.9, 18.4, -1.0; HRMS m/z Calcd for
3
21.6, 21.2, 21.1, 20.9, 19.0, −0.1, (C-1%%, JC-1%%ꢀH-3%%ax
6.1 Hz, cf. Refs. 12a, 21); HRMS m/z Calcd for
C75H92O24N4SSiNa [M+Na] 1515.5489. Found
1515.5514.
2-(Trimethylsilyl)ethyl (methyl 4,7,8,9-tetra-O-acetyl-
C54H75O28NSSiNa
1268.3876.
Methyl [2-(trimethylsilyl)ethyl (methyl 4,7,8,9-tetra-
O-acetyl-5-N,N-diacetylamino-3,5 -dideoxy-3-phenyl-
[M+Na]
1268.3863.
Found
5-N,N-diacetylamino-3,5-dideoxy-3-phenylthio-
thro-i- -gluco-non-2-ulopyranosylonate)-(2“3)-(2,6-
di-O-acetyl-i- -galactopyranosyl)-(1“4)-2,3-di-O-
D-ery-
L
D
acetyl-i-
D
-xylopyranoside (17).—Donor 2 (170 mg,
thio-
(2“8)-5-acetamido-4-O-benzoyl-3,5-dideoxy-9-O-p-
methoxybenzyl- -glycero-h- -galacto-non-2-ulopyran-
D -erythro-i-L -gluco-non-2-ulopyranosylonate)-
0.248 mmol) and acceptor 168c (72 mg, 0.124 mmol)
were dissolved in a mixture of MeCN (1.5 mL) and
D
D
,
CH2Cl2 (1 mL) and activated powdered 3 A molecular
osid]onate (19).—Donor 2 (138 mg, 0.201 mmol) and
acceptor 1812b (65 mg, 0.100 mmol) were dissolved in a
mixture of MeCN (1.5 mL) and CH2Cl2 (1 mL) and
sieves (250 mg) were added. The mixture was treated
essentially as in the preparation of 4, using AgOTf (140
mg, 0.546 mmol) in MeCN (1 mL), 0.248 mL of the 2
,
activated powdered 3 A molecular sieves (250 mg) were
i
M MeSBr solution, and Pr2NH (0.1 mL). Workup and
added. The mixture was treated essentially as in the
preparation of 4, using AgOTf (114 mg, 0.441 mmol) in
MeCN (1.2 mL), 0.20 mL of the 2 M MeSBr solution,
chromatographic purification (19:1“4:1 toluene–
MeCN) furnished 17 (90 mg, 60%). [h]2D3 +30° (c 0.60,

576
N. Hossain et al. / Carbohydrate Research 337 (2002) 569–580
i
and Pr2NH (0. 1 mL). Workup and chromatographic
J 7.6 Hz, H-1%), 4.41 (d, 1 H, J 7.7 Hz, H-1), 4.20 (t, 1
H, J 9.8 Hz, H-5%%), 2.68 (dd, 1 H, J 5.2, 13.1 Hz,
H-3eq), 2.39, 2.33, 2.13, 1.99, 1.97, 1.82 (6s, 3 H each,
Ac), 1.05 (m, 2 H, CH2Si), 0.05 (s, 9 H, SiMe3); 13C
NMR (CDCl3): l 174.6, 174.4, 170.9, 170.6, 170.2,
170.0, 168.2, 140.0, 139.6, 139.5, 139.2, 139.1, 138.7,
128.73, 128.71, 128.7, 128.51, 128.49, 128.44, 128.39,
128.2, 128.04, 128.00, 127.96, 127.9, 127.8, 127.6,
127.5, 103.5, 103.1, 99.6, 83.5, 82.4, 79.2, 77.3, 77.1,
76.6, 75.74, 75.67, 75.39, 75.37, 75.3, 73.7, 73.6, 73.1,
70.0, 69.4, 68.4, 67.79, 67.4, 67.2, 62.1, 57.2, 53.4, 37.5,
28.5, 26.8, 21.5, 21.21, 21.16, 21.0, 18.9, −0.1 (C-1%%,
3JC-1%%ꢀH-3%%ax=6.1 Hz; cf. Refs. 12a, 21); HRMS m/z
Calcd for C62H80N2NaO25SSi [M+Na] 1335.4437.
Found 1335.4434.
purification (19:1“3:1 toluene–MeCN) furnished 19
(58 mg, 46%). [h]D23 +20° (c 0.60, CHCl3); H NMR
1
(CDCl3): l 8.08–6.82 (m, 14 H, Ar), 6.07 (d, 1 H, J 9.3
Hz, NH), 5.88 (t, 1 H, J 9.8 Hz, H-4%), 5.32 (m, 1 H,
H-8%), 5.19 (m, 1 H, H-4), 5.14 (dd, 1 H, J 1.5, 8.6 Hz,
H-7%), 4.97 (dd, 1 H, J 1.5, 10.3 Hz, H-6%), 4.94 (m, 1 H,
H-8), 4.32 (m, 2 H, H-5,5%), 3.88, 3.84, 3.79 (3s, 3 H
each, COOCH3, OCH3), 3.53 (d, 1 H, J 9.9 Hz, H-3%),
3.40 (m, 1 H, OCH2CH2Si), 2.78 (dd, 1 H, J 12.8, 4.8
Hz, H-3eq), 2.38, 2.36, 2.21, 2.12, 2.06, 2.05, 1.90 (7s, 3
H each, Ac), 0.82 (t, 2 H, J 7.8 Hz, CH2Si), −0.03 (s,
9 H, SiMe3); 13C NMR (CDCl3): l 174.8, 174.0, 172.2,
171.4, 170.6, 170.4, 168.9, 168.6, 167.0, 159.3, 137.0,
133.8, 132.3, 131.5, 130.2, 129.5, 129.3, 129.2, 128.9,
128.7, 127.6, 125.7, 114.0, 100.9, 99.1, 77.7, 75.8, 75.7,
72.7, 72.0, 71.2, 70.3, 70.2, 69.2, 67.3, 62.4, 62.3, 59.6,
57.3, 55.6, 52.93, 52.91, 51.0, 38.3, 28.5, 26.6, 23.5, 21.5,
21.20, 21.16, 21.0, 18.3, −0.1; HRMS m/z Calcd for
C60H78N2NaO24SSi [M+Na] 1293.4322. Found
1293.4326. A sample of 19 was acetylated with Ac2O in
pyridine and the crude product was chromatographed
(19:1“3:1 toluene–MeCN) to give the corresponding
O-acetylated compound in 90% yield. [h]2D3 +44° (c
0.37, CHCl3); 1H NMR (CDCl3): l 8.05–6.84 (m, 14 H,
Ar), 6.30 (d, 1 H, J 9.4 Hz, NH), 5.80 (dd, 1 H, J 9.8,
10.8 Hz, H-4%), 5.69 (t, 1 H, J 1.7 Hz, H-7), 5.46 (m, 1
H, H-8%), 5.23 (m, 1 H, H-8), 5.17 (dd, 1 H, J 1.5, 9.2
Hz, H-7%), 5.05 (m, 1 H, H-4), 4.93 (dd, 1 H, J 1.5, 10.4
Hz, H-6%), 4.52 (d, 1 H, J 11.5 Hz, CH2Ph), 4.37 (t, 1 H,
J 10.1 Hz, H-5%), 4.18 (t, 1 H, J 9.8 Hz, H-5), 3.96 (s, 3
H, COOCH3), 3.87 (s, 3 H, COOCH3), 3.79 (s, 3 H,
OMe), 3.47 (d, 1 H, J 4.7, 12.7 Hz, H-3%), 3.39 (m, 1 H,
OCH2CH2Si), 2.87 (dd, 1 H, J 4.7, 12.7 Hz, H-3%), 2.38,
2.25, 2.17, 2.04, 2.03, 1.98, 1.86, 1.84 (8s, 3 H each, Ac),
0.90–0.75 (m, 2 H, CH2Si), −0.3 (s, 9 H, SiMe3); 13C
NMR (CDCl3): l 174.7, 174.0, 171.4, 171.3, 170.52,
170.50, 170.48, 170.0, 168.9, 168.7, 166.6, 138.0, 133.6,
131.9, 131.6, 130.3, 130.2, 129.5, 129.1, 129.0, 128.9,
128.7, 127.1, 114.1, 99.8, 99.2, 77.7, 74.7, 74.4, 72.0,
71.6, 71.2, 70.64, 70.61, 70.2, 69.2, 66.9, 62.4, 62.3, 60.2,
57.4, 55.7, 53.2, 53.0, 49.6, 38.3, 28.5, 26.8, 23.6, 21.8,
21.2, 21.14, 21.08, 20.9, 18.3, −0.1.
2-(Trimethylsilyl)ethyl
dideoxy- -glycero-h-
nate)-(2“3)-(2,4,6-tri-O-benzyl-i-
(1“4)-2,3,6-tri-O-benzyl-i- -glucopyranoside (21).—
(methyl
-galacto-non-2-ulopyranosylo-
-galactopyranosyl)-
5-acetamido-3,5-
D
D
D
D
Compound 20 (500 mg, 0.334 mmol) was dissolved in
MeOH (3 mL) and 1 M NaOMe in MeOH (0.05 mL)
was added. The mixture was left at 22 °C for 3 h and
neutralized with Duolite C26 (H+) resin. The resin was
filtered off and washed with MeOH. The filtrate was
concentrated and the residue was chromatographed
(19:1“1:2 toluene–acetone) to give 21 (401 mg, 93%).
[h]2D3 −4° (c 0.89, CHCl3); 1H NMR (CDCl3+
CD3OD): l 7.34–7.06 (m, 30 H, Ar), 4.96 (d, 1 H, J
10.6 Hz, CH2Ph), 4.87 (d, 1 H, J 11.4 Hz, CH2Ph), 4.86
(d, 1 H, J 11.0 Hz, CH2Ph), 4.72–4.66 (m, 3 H,
CH2Ph), 4.63 (d, 1 H, J 10.7 Hz, CH2Ph), 4.54 (d, 1 H,
J 11.9 Hz, CH2Ph), 4.44 (d, 1 H, J 11.4 Hz, CH2Ph),
4.42 (d, 1 H, J 8.0 Hz, H-1%), 4.41 (d, 1 H, J 11.8 Hz,
CH2Ph), 4.33 (d, 1 H, J 11.8 Hz, CH2Ph), 4.32 (d, 1 H,
J 7.8 Hz, H-1), 4.17 (d, 1 H, J 11.8 Hz, CH2Ph), 3.98
(dd, 1 H, J 3.1, 9.9 Hz, H-3%), 3.99–3.94 (m, 1 H,
OCH2CH2Si), 3.88 (brt, 1 H, J 9.3 Hz, H-4), 3.81 (m, 1
H, H-8%%), 3.77–3.69 (m, 5 H, H-4,6), 3.72 (s, 3 H,
COOCH3), 3.65 (dd, 1 H, J 4.5, 12.0 Hz, H-9), 3.59
(dd, 1 H, J 7.7, 9.8 Hz, H-2%), 3.58–3.49 (m, 4 H,
H-4,4%%,9%%, OCH2CH2Si), 3.48 (t, 1 H, J 9.1 Hz, H-3),
3.42–3.32 (m, 4 H, H-2), 3.29 (m, 1 H, H-5), 2.59 (dd,
1 H, J 4.7, 13.3 Hz, H-3%%eq), 1.99 (s, 3 H, Ac), 1.98
(brt, 1 H, J 13.3 Hz, H-3%%ax), 0.99 (m, 2 H, CH2Si),
−0.01 (s, 9 H, SiMe3); 13C NMR (CDCl3+CD3OD): l
174.3, 170.2, 139.6, 139.5, 139.2, 139.0, 138.7, 138.6,
128.8, 128.72, 128.70, 128.63, 128.57, 128.54, 128.47,
128.4, 128.13, 128.06, 128.02, 127.97, 127.91, 127.85,
127.7, 127.5, 103.5, 103.0, 100.2, 83.3, 82.2, 78.7, 77.7,
77.3, 77.0, 76.6, 75.8, 75.5, 75.43, 75.36, 74.7, 73.6, 73.0,
68.6, 68.5, 67.8, 64.0, 53.7, 53.0, 38.6, 23.2, 18.9, -0.1;
HRMS m/z Calcd for C71H89NNaO19Si [M+Na]
1310.5696. Found 1310.5743.
2-(Trimethylsilyl)ethyl (methyl 4,7,8,9-tetra-O-acetyl-
5 - N,N - diacetylamino - 3,5 - dideoxy -
galacto - non - 2 - ulopyranosylonate) - (2“3) - (2,4,6 - tri-
O-benzyl-i- -galactopyranosyl)-(1“4)-2,3,6-tri-O-
benzyl-i- -glucopyranoside (20).—Compound 12 (500
D - glycero - h - D-
D
D
mg, 0.311 mmol) was treated with triphenyltin hydride
(0.318 mL) in the presence of AIBN (51 mg, 0.311
mmol) in toluene (5 mL) at 120 °C for 4 h. The solvent
was removed and the residue was chromatographed
(19:1“4:1 toluene–MeCN) to give 20 (350 mg, 75%).
[h]2D3 −4° (c 1.0, CHCl3); H NMR (CDCl3): l 7.40–
2-(Trimethylsilyl)ethyl
dideoxy-9-p-toluenesulfonyl-
(methyl
5-acetamido-3,5-
-galacto-non-
1
7.12 (m, 30 H, Ar), 5.56 (m, 1 H, H-4%%), 5.43 (m, 1 H,
H-8%%), 5.15 (dd, 1 H, J 1.5, 8.2 Hz, H-7%%), 4.63 (d, 1 H,
D
-glycero-h-D
2-ulopyranosylonate)-(2“3)-(2,4,6-tri-O-benzyl-i-D-

N. Hossain et al. / Carbohydrate Research 337 (2002) 569–580
577
galactopyranosyl)-(1“4)-2,3,6-tri-O-benzyl-i-
D
-gluco-
138.3, 138.2, 128.41, 128.35, 128.30, 128.25, 128.16,
128.1, 128.0, 127.8, 127.73, 127.67, 127.61, 127.55,
127.4, 127.3, 127.2, 103.2, 102.6, 99.7, 82.9, 81.8,
78.4, 76.8, 76.7, 76.6, 75.3, 75.2, 75.1, 75.0, 74.2, 73.2,
72.6, 71.0, 69.1, 68.2, 68.1, 67.9, 67.5, 53.5, 53.4,
52.8, 38.4, 23.1, 18.5, -1.4; HRMS m/z Calcd for
pyranoside (22).—Compound 21 (505 mg, 0.392 mmol)
was dissolved in CH2Cl2 (3 mL) and pyridine (1.5 mL),
the mixture was cooled to −78 °C, and p-toluenesul-
fonyl chloride (149.5 mg, 0.784 mmol) was added. The
mixture was stirred for 50 min and kept at −78 °C for
2 days. Water (0.095 mL) was added and the mixture
was stirred at −78 °C for 20 min and at 22 °C for 30
min. The reaction mixture was concentrated and the
residue was chromatographed (19:1“2:1 toluene–
MeCN) to give 22 (512 mg, 91%). [h]2D3 −4° (c 0.62,
C71H88N4O18SiNa
1335.5763.
[M+Na]
1335.5737.
Found
2-(Trimethylsilyl)ethyl (methyl 5-acetamido-9-azido-
4-O-benzoyl-3,5,9-trideoxy- -glycero-h- -galacto-non-
2-ulopyranosylonate)-(2“3)-(2,4,6-tri-O-benzyl-i-
galactopyranosyl)-(1“4)-2,3,6-tri-O-benzyl-i- -gluco-
D
D
D
-
1
CHCl3); H NMR (CDCl3+CD3OD): l 7.72–7.05 (m,
D
34 H, Ar), 4.94 (d, 1 H, J 10.7 Hz, CH2Ph), 4.85 (d, 1
H, J 11.1 Hz, CH2Ph), 4.84 (d, 1 H, J 11.4 Hz, CH2Ph),
4.70–4.61 (m, 4 H, CH2Ph), 4.51 (d, 1 H, J 12.3 Hz,
CH2Ph), 4.40 (d, 1 H, J 11.9 Hz, CH2Ph), 4.39 (d, 1 H,
J 7.7 Hz, H-1%), 4.38 (d, 1 H, J 12.0 Hz, CH2Ph), 4.31
(d, 1 H, J 7.7 Hz, H-1), 4.29 (d, 1 H, J 11.6 Hz,
CH2Ph), 4.15 (dd, 1 H, J 2.6, 10.2 Hz, H-9%%), 4.14 (d, 1
H, J 11.9 Hz, CH2Ph), 4.06 (dd, 1 H, J 5.1, 10.2 Hz,
H-9%%), 3.70 (s, 3 H, COOCH3), 2.58 (dd, 1 H, J 4.6,
13.3 Hz, H-3%%eq), 2.38 (s, 3 H, SO2PhMe), 2.00 (s, 3 H,
Ac), 1.95 (brt, 1 H, J 12.0 Hz, H-3%%ax), 0.99 (m, 2 H,
CH2Si), −0.01 (s, 9 H, SiMe3); 13C NMR (CDCl3):
l 173.6, 169.6, 145.0, 139.1, 139.0, 138.7, 138.5,
138.2, 132.1, 129.9, 128.9, 128.24, 128.16, 128.1, 128.0,
127.9, 127.84, 127.80, 127.7, 127.5, 127.4, 127.3, 127.2,
127.0, 125.2, 103.0, 102.4, 99.5, 82.8, 81.7, 78.1, 76.6,
76.5, 76.3, 75.2, 75.1, 75.0, 74.9, 74.8, 73.8, 73.0, 72.4,
71.4, 69.3, 68.1, 67.84, 67.77, 67.6, 67.4, 53.3, 52.8,
38.1, 22.9, 21.6, 18.4, -1.5; HRMS m/z Calcd for
pyranoside (24).—Compound 23 (330 mg, 0.251 mmol)
was dissolved in CH2Cl2 (1.0 mL) and the mixture was
cooled to −45 °C. Et3N (88 mL) and benzoyl chloride
(0.044 mL, 0.379 mmol) were added and the mixture
was kept at −45 °C for 24 h. MeOH (200 mL) was
added and the temperature was raised to 22 °C. The
mixture was concentrated and the residue was dissolved
in EtOAc (20 mL), washed successively with satd aq
NaHCO3 solution (3×3 mL) and water (3 mL), dried
(Na2SO4), filtered, and concentrated. The residue was
chromatographed (19:1“4:1 toluene–MeCN) to give
24 (300 mg, 84%). Mp 76–79 °C; [h]2D3 −32° (c 1.0,
1
CHCl3); H NMR (CDCl3+CD3OD): l 7.98–7.46 (m,
5 H, Ar), 7.34–7.03 (m, 30 H, Ar), 5.12 (ddd, 1 H, J
4.9, 10.5, 11.7 Hz, H-4%%), 4.99 (d, 1 H, J 10.7 Hz,
CH2Ph), 4.90–4.87 (m, 2 H, CH2Ph), 4.73 (d, 1 H, J
11.4 Hz, CH2Ph), 4.72 (d, 1 H, J 11.0 Hz, CH2Ph), 4.66
(d, 1 H, J 11.4 Hz, CH2Ph), 4.62 (d, 1 H, J 11.9 Hz,
CH2Ph), 4.58 (d, 1 H, J 11.1 Hz, CH2Ph), 4.48 (d, 1 H,
J 11.4 Hz, CH2Ph), 4.46 (d, 1 H, J 7.7 Hz, H-1%), 4.43
(d, 1 H, J 12.0 Hz, CH2Ph), 4.35 (d, 1 H, J 7.9 Hz,
H-1), 4.21 (d, 1 H, J 11.8 Hz, CH2Ph), 4.18 (brt, 1 H,
J 10.3 Hz, H-5%%), 4.07 (dd, 1 H, J 3.3, 10.0 Hz, H-3%),
4.00 (m, 1 H, H-8%%), 3.99 (m, 1 H, OCH2CH2Si), 3.92
(brt, 1 H, J 9.4 Hz, H-4), 3.89 (s, 3 H, COOCH3),
3.77–3.74 (m, 1 H, H-9%%), 3.69 (dd, 1 H, J 7.4, 10.1 Hz,
H-2%), 3.60–3.46 (m, 8 H, H-2,5, OCH2CH2Si), 2.50
(dd, 1 H, J 4.9, 13.2 Hz, H-3%%eq), 2.25 (brt, 1 H, J 13.0
Hz, H-3%%ax), 1.93 (s, 3 H, Ac), 1.01 (m, 2 H, CH2Si),
0.00 (s, 9 H, SiMe3); 13C NMR (CDCl3): l 173.1, 169.1,
167.0, 139.0, 138.7, 138.4, 138.3, 138.2, 133.9, 129.8,
128.7, 128.5, 128.2, 128.1, 128.0, 127.94, 127.85, 127.7,
127.5, 127.41, 127.37, 127.3, 127.2, 127.0, 103.0, 102.4,
99.6, 82.8, 81.7, 78.3, 77.0, 76.4, 76.3, 75.2, 75.0, 74.9,
74.8, 74.3, 73.2, 73.1, 72.5, 70.7, 69.7, 68.9, 68.2, 67.8,
67.2, 53.5, 53.3, 50.8, 34.9, 22.9, 18.4, −1.5.
C78H95NO21SSiNa
1464.5747.
[M+Na]
1464.5785.
Found
2-(Trimethylsilyl)ethyl (methyl 5-acetamido-9-azido-
3,5,9-trideoxy- -glycero-h- -galacto-non-2-ulopyrano-
sylonate)-(2“3)-(2,4,6-tri-O-benzyl-i- -galactopyran-
osyl)-(1“4)-2,3,6-tri-O-benzyl-i- -glucopyranoside
D
D
D
D
(23).—To a solution of 22 (430 mg, 0.298 mmol) in
DMF (3 mL) was added 18-crown-6 (32 mg) followed
by NaN3 (97 mg, 1.490 mmol) and the reaction mixture
was stirred at 60 °C for 24 h. The mixture was cooled to
22 °C, filtered, and the filtrate was concentrated. The
residue was chromatographed (19:1“2:1 toluene–
MeCN) to give 23 (330 mg, 84%). [h]2D3 −1° (c 0.73,
1
CHCl3); IR (neat); w 2090 cm−1; H NMR (CDCl3+
CD3OD): l 7.35–7.08 (m, 30 H, Ar), 4.98 (d, 1 H, J
10.7 Hz, CH2Ph), 4.88 (d, 2 H, J 11.2 Hz, CH2Ph),
4.73–4.63 (m, 4 H, CH2Ph), 4.56 (d, 1 H, J 11.9 Hz,
CH2Ph), 4.46 (d, 1 H, J 11.5 Hz, CH2Ph), 4.44 (d, 1 H,
J 11.9 Hz, CH2Ph), 4.43 (d, 1 H, J 7.7 Hz, H-1%), 4.35
(d, 1 H, J 11.8 Hz, CH2Ph), 4.34 (d, 1 H, J 7.8 Hz,
H-1), 4.20 (d, 1 H, J 11.8 Hz, CH2Ph), 3.73 (s, 3 H,
COOCH3), 2.60 (dd, 1 H, J 4.7, 13.3 Hz, H-3%%eq), 2.03
(s, 3 H, Ac), 1.99 (brdd, 1 H, J 12.1, 13.0 Hz, H-3%%ax),
1.01 (m, 2 H, CH2Si), 0.01 (s, 9 H, SiMe3); 13C NMR
(CDCl3): l 173.5, 169.6, 139.2, 139.1, 138.8, 138.6,
2-(Trimethylsilyl)ethyl (methyl 4,7,8,9-tetra-O-acetyl-
5-N,N-diacetylamino-3,5-dideoxy-3-phenylthio-
thro - i - - gluco - non - 2 - ulopyranosylonate) - (2“8)-
(methyl 5 - acetamido - 9 - azido - 4 - O - benzoyl - 3,5,9 - tri-
deoxy- -glycero-h- -galacto-non-2-ulopyranosylonate)-
(2“3)-(2,4,6-tri-O-benzyl-i- -galactopyranosyl)-(1“
4)-2,3,6-tri-O-benzyl-i- -glucopyranoside (25).—The
reaction was performed as described for 4 using donor
D-ery-
L
D
D
D
D

578
N. Hossain et al. / Carbohydrate Research 337 (2002) 569–580
2 (319 mg, 0.46 mmol), acceptor 24 (220 mg, 0.155
mmol), MS (250 mg), CH3CN (1.5 mL), CH2Cl2 (1.0
mL), AgOTf (299 mg, 1.16 mmol) in CH3CN (1.0 mL),
MeSBr (0.465 mL). After addition of MeSBr the reac-
tion mixture was stirred at −45 °C for 3.5 h, then
iPr2NH (0.2 mL) was added the stirring was continued
for 15 min and the reaction mixture was allowed to
reach 22 °C. The mixture was filtered and the filtrate
was concentrated. The residue was chromatographed
(19:1“3:1 toluene–MeCN) to give 25 (157 mg, 50%).
174.4, 174.3, 169.8, 169.2, 139.6, 139.5, 139.2, 138.89,
138.85, 138.4, 135.4, 131.1, 129.3, 128.71, 128.65,
128.61, 128.58, 128.50, 128.45, 128.4, 128.3, 128.20,
128.17, 128.0, 127.93, 127.90, 127.8, 127.7, 127.6, 127.4,
103.4, 103.3, 101.5, 99.4, 83.3, 82.2, 78.8, 78.0, 77.8,
76.4, 76.2, 76.0, 75.80, 75.77, 75.6, 75.40, 75.35, 73.7,
73.5, 73.4, 72.7, 72.1, 71.3, 69.0, 68.9, 68.0, 67.9, 67.8,
66.7, 57.1, 53.5, 53.4, 52.8, 52.4, 40.2, 23.1, 22.9, 18.89,
-0.10; HRMS m/z Calcd for C89H111N5NaO26SSi [M+
Na] 1748.6875. Found 1748.6895.
1
[h]2D3 90° (c 1.0, CHCl3); H NMR (CDCl3) l 8.10–
2-(Trimethylsilyl)ethyl (5-acetamido-3,5-dideoxy-3-
7.11 (m, 40 H, Ar), 5.93 (t, 1 H, J 10.2 Hz, H-4%%%), 5.76
(d, 1 H, J 8.9 Hz, NH), 5.36–5.24 (m, 2 H, H-4%%,
H-8%%%), 5.12 (dd, 1 H, J 1.2, 7.8 Hz, H-7%%%), 5.00 (m, 3
H, H-6%%%), 4.91 (d, 1 H, J 11.1 Hz, CH2Ph), 4.69 (d, 1
H, J 10.6 Hz, CH2Ph), 4.28 (t, 1 H, J 9.9 Hz, H-5%%%),
4.24 (m, 3 H, H-5%%), 4.12 (dd, 1 H, J 2.7, 12.6 Hz,
H-9%%%), 3.87 (s, 3 H, COOCH3), 3.82 (s, 3 H, COOCH3),
3.40 (d, 1 H, J 10.7 Hz, H-3%%%), 2.61 (dd, 1 H, J 5.0,
13.1 Hz, H-3%%), 2.39, 2.26, 2.06, 2.05, 1.99, 1.98, 1.86
(7s, 3 H each), 1.02 (m, 2 H, CH2Si), 0.01 (s, 9 H,
SiMe3): 13C NMR (CDCl3) l 174.9, 174.1, 172.4, 171.1,
170.6, 170.4, 170.01, 169.0, 167.7, 167.2, 139.9, 139.6,
139.0, 138.9, 138.8, 131.8, 130.3, 129.7, 129.5, 129.0,
128.73, 128.69, 128.6, 128.50, 128.45, 128.4, 128.1,
128.04, 127.97, 127.9, 127.80, 127.75, 127.6, 127.5,
103.4, 101.8, 99.2, 83.4, 82.3, 78.9, 77.7, 76.8, 76.3, 76.2,
75.9, 75.7, 75.4, 73.64, 73.55, 73.2, 71.1, 70.2, 70.1,,
69.8, 68.9, 68.2, 67.8, 66.9, 62.3, 59.9, 57.8, 53.4, 52.9,
52.3, 51.2, 36.7, 28.4, 26.3, 23.5, 21.3, 21.10, 21.05, 18.9,
−0.1; HRMS m/z Calcd for C106H125N5O32NaSSi
[M+Na] 2062.7695. Found 2062.7729.
phenylthio-
acid)-(2“8)-(methyl
trideoxy- -glycero-h-
nate)-(2“3)-(2,4,6-tri-O-benzyl-i-
(1“4)-2,3,6-tri-O-benzyl-i- -glucopyranoside 1%%%-9%%-
D
-erythro-i-
L
-gluco-non-2-ulopyranosylonic
5-acetamido-9-amino-3,5,9-
D
D
-galacto-non-2-ulopyranosylo-
-galactopyranosyl)-
D
D
lactam (27).—To a stirred solution of 26 (125 mg,
0.072 mmol) in 8:1 THF–water (0.9 mL) was added
Ph3P (76 mg, 0.2892 mmol), and the mixture was stirred
at 40 °C for 24 h. The reaction mixture was co-concen-
trated with toluene–acetone. The residue was chro-
matographed (1–10% MeOH in CH2Cl2) to give 27
(104 mg, 86%). Mp 124–126 °C (hexane–Et2O,
MeOH); [h]2D3 −28° (c 0.52, CHCl3); IR (film); w 1735
cm−1 (COOCH3), 1730–1620 (CONH); 1H NMR
(CD3OD): l 7.56–7.03 (m, 35 H, Ar), 5.00 (d, 1 H, J
10.6 Hz, CH2Ph), 4.95 (d, 1 H, J 11.4 Hz, CH2Ph), 4.85
(d, 1 H, J 11.0 Hz, CH2Ph), 4.78 (d, 1 H, J 10.6 Hz,
CH2Ph), 4.70 (d, 1 H, J 10.8 Hz, CH2Ph), 4.67 (d, 1 H,
J 10.8 Hz, CH2Ph), 4.57 (d, 1 H, J 11.0 Hz, CH2Ph),
4.54 (d, 1 H, J 11.8 Hz, CH2Ph), 4.50 (d, 1 H, J 11.4
Hz, CH2Ph), 4.44–4.37 (m, 6 H, H-1,1%,4%%%,8%%, CH2Ph),
4.18 (d, 1 H, J 12.0 Hz, CH2Ph), 4.11 (dd, 1 H, J 3.0,
10.0 Hz, H-3%), 3.55 (dd, 1 H, J 5.9, 13.2 Hz, H-9%%),
3.48 (t, 1 H, J 9.1 Hz, H-3), 3.46 (s, 3 H, COOCH3),
3.23 (dd, 1 H, J 7.9, 9.1 Hz, H-2), 3.01 (d, 1 H, J 10.3
Hz, H-3%%%), 2.61 (dd, 1 H, J 4.6, 13.2 Hz, H-3%%eq), 2.08,
2.02 (2s, 3 H each, NAc), 2.00 (brt, 1 H, J 13.0 Hz,
H-3%%ax), 0.99 (brt, 2 H, J 8.0 Hz, CH2Si), 0.04 (s, 9 H,
SiMe3); 13C NMR (CD3OD): l 175.7, 175.4, 170.3,
169.3, 140.7, 140.4, 140.2, 140.1, 139.9, 139.7, 139.6,
132.0, 130.0, 129.7, 129.6, 129.5, 129.39, 129.36, 129.2,
129.10, 129.06, 129.0, 128.70, 128.66, 128.5, 128.4,
127.4, 104.3, 103.9, 101.4, 101.2, 84.1, 83.1, 79.7, 78.2,
77.4, 77.3, 76.5, 76.1, 75.9, 74.9, 74.4, 74.3, 74.2, 72.5,
72.4, 71.8, 70.3, 69.7, 69.3, 68.7, 68.4, 65.6, 62.2, 54.1,
54.0, 53.2, 42.2, 40.1, 23.1, 22.7, 19.4, −1.1; HRMS
m/z Calcd for C88H109N3NaO25Si [M+Na] 1690.6708.
Found 1690.6698.
2-(Trimethylsilyl)ethyl
dideoxy-3-phenylthio- -erythro-i-
ranosylonate)-(2“8)-(methyl
3,5,9-trideoxy- -glycero-h-
(methyl
5-acetamido-3,5-
-gluco-non-2-ulopy-
D
L
5-acetamido-9-azido-
D
D
-galacto-non-2-ulopyrano-
sylonate)-(2“3)-(2,4,6-tri-O-benzyl-i-D-galactopyran-
osyl)-(1“4)-2,3,6-tri-O-benzyl-i- -glucopyranoside
D
(26).—Compound 25 (118 mg, 0.058 mmol) was dis-
solved in MeOH (2 mL) and 1 M NaOMe in MeOH
(0.04 mL) was added. The mixture was left at 22 °C for
3.5 h and neutralized with Duolite C26 (H+) resin. The
resin was filtered off and washed with MeOH. The
filtrate was concentrated and the residue was chro-
matographed (1–10% MeOH in CH2Cl2) to give 26 (82
1
mg, 82%). H NMR (CD3OD): l 7.64–7.04 (m, 35 H,
Ar), 4.98 (d, 1 H, J 10.6 Hz, CH2Ph), 4.91–4.79 (m, 3
H, CH2Ph), 4.71–4.66 (m 3 H, CH2Ph), 4.56 (d, 1 H, J
10.5 Hz, CH2Ph), 4.42–4.37 (m, 4 H, H-1,1%, CH2Ph),
4.30 (s, 2 H, CH2Ph), 4.21 (d, 1 H, J 11.9 Hz, CH2Ph),
4.20 (dd, 1 H, J 2.8, 9.8 Hz, H-3%), 3.87, 3.79 (2s, 3 H
each, COOCH3), 3.49 (brt, 1 H, J 9.1 Hz, H-3), 3.25
(dd, 1 H, J 7.8, 9.2 Hz, H-2), 2.77 (brdd, 1 H, J 4.7,
12.7 Hz, H-3%%eq), 2.08, 2.03 (2s, 3 H each, Ac), 1.90
(brt, 1 H, J 12.6 Hz, H-3%%ax), 1.00 (brt, 1 H, J 8.0 Hz,
CH2Si), 0.03 (s, 9 H, SiMe3); 13C NMR (CD3OD): l
2-(Trimethylsilyl)ethyl (5-acetamido-3,5-dideoxy-3-
phenylthio-
acid)-(2“8)-(methyl 5,9-diacetamido-3,5,9-trideoxy-
glycero-h- -galacto-non-2-ulopyranosylonate)-(2“3)-
(2,4,6-tri-O-benzyl-i- -galactopyranosyl)-(1“4)-2,3,6-
tri-O-benzyl-i- -glucopyranoside 1%%%-9%%-lactam (28).—
To a solution of 27 (88 mg, 0.053 mmol) in pyridine
D-erythro-i-L-gluco-non-2-ulopyranosylonic
D
-
D
D
D

N. Hossain et al. / Carbohydrate Research 337 (2002) 569–580
579
(0.5 mL), Ac2O (0.5 mL) and DMAP (3 mg) were
added. The reaction mixture was kept at rt overnight.
Methanol (1 mL) was added and the reaction was
co-concentrated with toluene and methanol. The
residue was chromatographed (9:1“1:1 toluene–ace-
tone) to give 28 (100 mg, 99%). [h]2D3 −2° (c 1.0,
the mixture was kept at 22 °C for 12 h. The mixture
was neutralized with Duolite C26 (H+) resin. The resin
was filtered off and washed with MeOH. The filtrate
was concentrated and the residue was chromatographed
(1–12% MeOH in CH2Cl2) to give 30 (23 mg, 83%).
[h]2D3 −22° (c 0.90, CHCl3); 1H NMR (CD3OD): l
7.39–7.06 (m, 30 H, Ar), 5.02 (d, 1 H, J 11.5 Hz,
CH2Ph), 5.00 (d, 1 H, J 10.0 Hz, CH2Ph), 4.84 (d, 1 H,
J 11.0 Hz, CH2Ph), 4.78 (d, 1 H, J 11.4 Hz, CH2Ph),
4.68 (d, 2 H, J 11.1 Hz, CH2Ph), 4.58–4.54 (m, 3 H,
CH2Ph), 4.43 (d, 1 H, J 7.9 Hz, H-1%), 4.43 (m, 1 H,
H-4%%%), 4.40 (d, 1 H, J 7.7 Hz, H-1), 4.38 (d, 1 H, J 11.1
Hz, CH2Ph), 4.37 (d, 1 H, J 11.8 Hz, CH2Ph), 4.25
(ddd, 1 H, J 6.1, 10.0, 10.0 Hz, H-8%%), 4.14 (d, 1 H, J
11.9 Hz, CH2Ph), 4.37 (d, 1 H, J 11.8 Hz, CH2Ph), 4.10
(dd, 1 H, J 2.9, 9.9 Hz, H-3%), 3.99 (m, 1 H, OCH2),
3.70 (s, 3 H, COOCH3), 3.21 (brdd, 1 H, J 7.9, 9.1 Hz,
H-2), 2.66 (dd, 1 H, J 4.7, 12.9 Hz, H-3%%eq), 2.44 (dd,
1 H, J 5.3, 12.8 Hz, H-3%%%eq), 2.04 (s, 3 H, Ac), 2.02 (m,
1 H, H-3%%ax), 2.01 (s, 3 H, Ac), 1.83 (brt, 1 H, J 12.5
Hz, H-3%%%ax), 0.99 (brt, 2 H, J 8.0 Hz, CH2Si), 0.03 (s,
9 H, SiMe3); 13C NMR (CD3OD): l 175.8, 175.6, 171.1,
170.5, 141.0, 140.4, 140.3, 140.2, 140.0, 139.7, 129.84,
129.77, 129.74, 129.68, 129.5, 129.41, 129.38, 129.32,
129.30, 129.23, 129.15, 129.12, 129.11, 129.04, 128.98,
128.7, 128.5, 128.4, 104.4, 103.8, 102.1, 98.9, 84.1, 83.2,
79.8, 78.4, 77.5, 77.3, 76.5, 76.2, 76.1, 75.9, 74.5, 74.4,
74.3, 73.8, 72.0, 71.5, 69.9, 69.4, 69.3, 68.9, 68.5, 65.4,
54.4, 53.5, 53.3, 43.2, 42.1, 39.7, 23.0, 22.7, 19.5, −1.1;
HRMS m/z Calcd for C82H105N3NaO25Si [M+Na]
1582.6704. Found 1582.6733.
1
CHCl3); H NMR (CDCl3): l 7.41–7.06 (m, 35 H, Ar),
5.63 (d, 1 H, J 9.5 Hz, NH), 5.57 (t, 1 H, J 10.7 Hz,
H-4%%%), 5.02 (dd, 1 H, J 7.1, 11.1 Hz, H-4%%), 4.91 (d, 1
H, J 11.0 Hz, CH2Ph), 4.73 (d, 1 H, J 11.2 Hz, CH2Ph),
4.57 (d, 1 H, J 12.0 Hz, CH2Ph), 4.20 (t, 1 H, J 9.9 Hz,
H-5%%%), 3.76 (s, 3 H, COOCH3), 3.30 (d, 1 H, J 11.0 Hz,
H-3%%%), 2.53 (s, 3 H, CONAc), 2.44 (dd, 1 H, J 5.2, 13.8
Hz, H-3%%eq), 2.17, 2.03, 2.00, 1.98, 1.93, 1.90, 1.89,
1.88, (8s, 3 H each, Ac), 1.04 (m, 2 H, CH2Si), 0.02 (s,
9 H, SiMe3); 13C NMR (CDCl3): l 171.6, 171.3, 171.0,
170.94, 170.88, 170.7, 170.4, 170.3, 170.1, 168.6, 166.9,
139.7, 139.6, 139.2, 139.0, 139.0, 138.8, 135.9, 131.3,
129.6, 129.5, 128.8, 128.7, 128.6, 128.51, 128.46, 128.39,
128.37, 128.3, 128.13, 128.07, 127.99, 127.98, 127.94,
127.92, 127.89, 127.8, 127.7, 127.4, 103.5, 103.1, 100.6,
100.2, 83.5, 82.3, 78.8, 77.7, 77.5, 77.3, 77.0, 75.7, 75.6,
75.4, 75.3, 75.2, 74.3, 73.8, 73.6, 73.4, 73.2, 72.9, 71.9,
69.8, 69.1, 69.0, 68.5, 67.8, 67.3, 62.7, 58.9, 53.3, 50.4,
50.1, 40.46, 35.9, 27.7, 23.6, 23.5, 21.3, 21.18, 21.16,
21.1, 21.0, 20.9, 18.9, −1.0.
2-(Trimethylsilyl)ethyl (5-acetamido-4,7,8,9-tetra-O-
acetyl-3,5-dideoxy-
ranosylonic acid)-(2“8)-(methyl 5,9-diacetamido-4,7-
di-O-acetyl-3,5,9-trideoxy- -glycero-h- -galacto-non-2-
ulopyranosylonate) - (2“3) - (2,4,6 - tri - O - benzyl - i -
galactopyranosyl)-(1“4)-2,3,6-tri-O-benzyl-i- -gluco-
D-glycero-h-D-galacto-non-2-ulopy-
D
D
D
-
2-(Trimethylsilyl)ethyl (5-acetamido-3,5-dideoxy-
glycero - h -
(2“8)-(methyl 5-acetamido-9-amino-3,5,9-trideoxy-
glycero-h-
(i - - galactopyranosyl) - (1“4) - i -
D
-
D
D
- galacto - non - 2 - ulopyranosylonic acid)-
pyranoside 1%%%-9%%-Lactam (29).—Compound 28 (65 mg,
0.033 mmol) was treated with Ph3SnH (0.085 mL, 0.331
mmol) and AIBN (6 mg) in toluene (1.5 mL) at 120 °C
for 5 h. The solvent was removed and the residue was
chromatographed (9:1“1:1 toluene–MeCN) to give 29
(40 mg, 65%). 13C NMR (CDCl3): l 171.44, 171.36,
171.2, 171.0, 170.9, 170.81, 170.77, 170.5, 170.3, 168.8,
168.5, 139.8, 139.6, 139.2, 139.0, 138.9, 138.7, 131.3,
129.6, 128.8, 128.7, 128.6, 128.52, 128.47, 128.45, 128.4,
128.3, 128.1, 128.0, 127.9, 127.8, 127.7, 127.5, 103.5,
103.1, 100.8, 97.6, 83.5, 82.3, 78.9, 77.7, 77.3, 77.1, 76.8,
75.8, 75.5, 75.4, 75.3, 75.0, 74.3, 73.6, 73.2, 72.2, 70.4,
70.2, 69.3, 69.0, 68.3, 68.1, 67.8, 62.7, 53.2, 49.7, 49.6,
40.7, 39.8, 35.9, 27.6, 23.6, 23.4, 21.4, 21.31, 21.29, 21.2,
D
-
D
-galacto-non-2-ulopyranosylonate)-(2“3)-
- glucopyranoside
D
D
1%%%-9%%-Lactam (31).—Compound 30 (40 mg, 0.026
mmol) was dissolved in EtOH (7 mL) and hydro-
genated (H2, Pd(OH)2–C, 20%, 100 mg, 1 atm) at 22 °C
overnight. The catalyst was filtered off, washed with
MeOH and the filtrate was concentrated to give 31 (25
mg, 96%). [h]2D3 −34° (c 0.5, MeOH); 1H NMR
(CD3OD): l 4.44 (d, 1 H, J 7.8 Hz, H-1%), 4.43 (m, 1 H,
H-4%%%), 4.30 (d, 1 H, J 7.9 Hz, H-1), 4.14 (ddd, 1 H, J
6.2, 8.5, 10.7 Hz, H-8%%), 3.81 (s, 3 H, COOCH3), 3.21 (t,
1 H, J 7.9 Hz, H-2), 2.73 (dd, 1 H, J 4.5, 12.9 Hz,
H-3%%eq), 2.45 (dd, 1 H, J 5.6, 12.8 Hz, H-3%%%eq), 2.33,
2.05 (2s, 3 H each, Ac), 1.55 (dd, 1 H, J 11.1, 12.6 Hz,
H-3%%%ax), 1.00 (m, 2 H, CH2Si), 0.03 (s, 9 H, SiMe3);
13C NMR (CD3OD): l 174.6, 174.1, 169.9, 169.5, 103.9,
102.7, 99.3, 97.8, 80.0, 76.9, 75.6, 75.4, 73.8, 73.7, 73.4,
72.1, 71.2, 70.8, 69.8, 68.7, 68.4, 67.81, 67.77, 67.2, 64.3,
61.3, 61.1, 57.2, 53.2, 52.3, 41.7, 40.8, 40.1, 21.9, 21.6,
18.1, −2.4; HRMS m/z Calcd for C40H69NaN3O25Si
[M+Na] 1042.3887. Found 1042.3896.
21.1, 20.9, 18.9, −1.0; HRMS m/z Calcd for C96H119
-
N3NaO32Si [M+Na] 1876.7444. Found 1876.7435.
2-(Trimethylsilyl)ethyl (5-acetamido-3,5-dideoxy-
D
-
glycero-h-
D
-galacto-non-2-ulopyranosylonic acid)-(2“
8)-(methyl
5-acetamido-9-amino-3,5,9-trideoxy-
D
-
glycero-h-
(2,4,6-tri-O-benzyl-i-
tri-O-benzyl-i- -glucopyranoside 1%%%-9%%-lactam (30).—
D
-galacto-non-2-ulopyranosylonate)-(2“3)-
D
-galactopyranosyl)-(1“4)-2,3,6-
D
To a solution of 29 (33 mg, 0.018 mmol) in MeOH (0.7
2-(Trimethylsilyl)ethyl (5-acetamido-4,7,8,9-tetra-O-
mL) was added 1 M methanolic NaOMe (0.12 mL) and
acetyl-3,5-dideoxy-D-glycero-h-D-galacto-non-2-ulopy-

580
N. Hossain et al. / Carbohydrate Research 337 (2002) 569–580
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8. (a) Ray, A. K.; Nilsson, U.; Magnusson, G. J. Am.
Chem. Soc. 1992, 114, 2256–2257;
ranosylonic acid)-(2“8)-(methyl 5,9-diacetamido-4,7-
di-O-acetyl-3,5,9-trideoxy- -glycero-h- -galacto-non-2-
ulopyranosylonate) - (2“3) - (2,4,6 - tri - O - acetyl - i -
galactopyranosyl)-(1“4)-2,3,6-tri-O-acetyl-i- -gluco-
D
D
D
-
D
(b) Wilstermann, M.; Kononov, L. O.; Nilsson, U.; Ray,
A. K.; Magnusson, G. J. Am. Chem. Soc. 1995, 117,
4742–4754;
(c) Wilstermann, M.; Magnusson, G. J. Org. Chem. 1997,
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(d) Ellervik, U.; Grundberg, H.; Magnusson, G. J. Org.
Chem. 1998, 63, 9323–9338.
pyranoside 1%%%-9%%-lactam (32).—To a solution of 31 (28
mg, 0.027) in pyridine (0.5 mL) was added Ac2O (0.5
mL) followed by DMAP (1 mg) and the mixture was
kept at 22 °C overnight. Methanol (1 mL) was added
and the mixture was stirred at 22 °C for 5 min, and
co-concentrated with toluene. The residue was chro-
matographed (9:1“1:1 toluene–acetone) to give 32 (23
9. Ding, K.; Rose´n, A.; Ray, A. K.; Magnusson, G. Glyco-
conjugate J. 1993, 9, 303–306.
10. Magnusson, G.; Ding, K.; Nilsson, U.; Ray, A. K.;
Rose´n, A.; Sjo¨gren, H.-O. In Complex Carbohydrates in
Drug Research, Alfred Benzon Symposium 36; Bock, K.;
Clausen, H., Eds.; Munksgaard: Copenhagen, 1994; pp.
89–100.
1
mg, 53%). H NMR (CDCl3): l 5.50 (m, 1 H, H-4%%%),
5.30 (t, 1 H, J 9.3 Hz, H-3), 5.10 (m, 1 H, H-4%%), 4.74
(dd, 1 H, J 8.1, 9.5 Hz, H-2), 4.46 (d, 1 H, J 8.1 Hz,
H-1), 3.90 (s, 3 H, COOCH3), 2.62 (dd, 1 H, J 5.0, 12.5
Hz, H-3%%%eq), 2.59 (s, 3 H, Ac), 2.45 (dd, 1 H, J 5.5,
13.3 Hz, H-3%%eq), 2.33, 2.14, 2.13, 2.11, 2.10, 2.05, 2.04,
2.03, 2.02, 2.01, 1.92, 1.90 (12s, 42 H, Ac), 1.74 (t, 1 H,
J 12.5 Hz, H-3%%%ax), 0.90 (m, 2 H, CH2Si), 0.01 (s, 9 H,
SiMe3); 13C NMR (CDCl3): l 171.6, 171.5, 171.12,
171.05, 170.84, 170.78, 170.77, 170.71, 170.65, 170.5,
170.4, 169.94, 169.88, 169.80, 169.77, 168.80, 167.1,
101.3, 100.0, 98.4, 98.0, 77.6, 77.3, 77.0, 76.1, 75.2, 73.9,
72.7, 72.5, 72.3, 71.0, 70.5, 70.2, 69.3, 68.9, 68.6,
68.0, 67.5, 66.9, 63.9, 61.71, 61.66, 53.7, 50.8, 48.9,
40.0, 38.5, 38.1, 28.0, 23.74, 23.70, 21.33, 21.25, 21.21,
21.16, 21.12, 21.08, 18.3, −1.0; HRMS m/z Calcd for
11. (a) Tietze, L. F.; Keim, H. Angew. Chem., Int. Ed. Engl.
1997, 36, 1615–1617;
(b) Tietze, L. F.; Keim, H.; Janßen, C. O.; Tap-
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2801–2808.
12. (a) Erce´govic, T.; Magnusson, G. J. Chem. Soc., Chem.
Commun. 1994, 831–832;
(b) Erce´govic, T.; Magnusson, G. J. Org. Chem. 1995, 60,
3378–3384;
(c) Martichonok, V.; Whitesides, G. M. J. Am. Chem.
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14. (a) Ito, Y.; Ogawa, T. Tetrahedron Lett. 1988, 29, 3987–
3990;
C66H95N3NaO38Si
1588.5240.
[M+Na]
1588.5260.
Found
(b) Ito, Y.; Ogawa, T. Tetrahedron 1990, 46, 89–102;
(c) Ito, Y.; Numata, M.; Sugimoto, M.; Ogawa, T. J. Am.
Chem. Soc. 1989, 111, 8508–8510;
Acknowledgements
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This work was supported by the Swedish Natural
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