cooled to −30 ◦C. To the suspension was added NIS (36 mg,
0.16 mmol) and TfOH (0.3 M in Et2O, 83 mm3, 25 lmol),
subsequently. After being stirred for 30 min, the suspension was
diluted with CHCl3 and filtered through a pad of celite. The filtrate
was washed with 10% aqueous Na2S2O3 solution and saturated
aqueous NaHCO3 solution, subsequently. The organic layer was
dried (MgSO4) and concentrated. The residue was purified on a
column of silica gel (hexane–EtOAc 2 : 1 → 1 : 1) to yield a mixture
of 9 and hydroxyethyl glycoside 10. The mixture was acetylated
with Ac2O (0.5 cm3) and pyridine (0.5 cm3) and purified by silica
gel column chromatography (hexane–EtOAc 3 : 2) to yield 9
(65.2 mg, 66%) as a colourless syrup; Rf 0.16 (hexane–EtOAc 2 :
1); [a]3D0 + 4.8 (c 1.27, CHCl3); dH (400 MHz, CDCl3, COSY)
8.07–7.13 (30 H, m, Ar), 5.88–5.87 (2 H, m, H-4L, 4D), 5.75 (1 H,
dd, J2D,3D 10.5, J2D,1D 8.1, H-2D), 5.74 (1 H, dd, J2L,3L 10.4, J2L,1L
7.9, H-2L), 5.52 (1 H, dd, J3D,4D 3.4, H-3D), 5.49 (1 H, dd, J3L,4L
3.4, H-3L), 4.79 (1 H, d, H-1D), 4.76 (1 H, d, H-1L), 4.67 (1 H, d,
J 6.9, OCH2O), 4.57 (1 H, d, J 6.9, OCH2O), 4.18–4.03 (6 H, m,
H-5L, 5D, OCH2CH2Si,OCH2CH2O), 3.83–3.61 (6 H, m, H-6aL,
6bL, 6aD, 6bD, OCH2CH2Si, OCH2CH2O), 1.69 (3 H, s, Ac),
0.91 (2 H, m, OCH2CH2Si), −0.07 (9 H, s, SiMe3); dC (67.8 MHz,
CDCl3) 170.6, 165.4, 165.3, 165.0, 164.9, 133.4, 133.3, 133.07,
133.02, 132.9, 129.9, 129.6, 129.59, 129.46, 129.3, 129.1, 129.0,
128.8, 128.7, 128.48, 128.47, 128.2, 128.16, 128.11, 101.3, 100.9,
96.1, 72.7, 72.4, 72.1, 71.8, 69.9, 69.6, 68.4, 67.8, 67.5, 66.3, 63.0,
20.4, 18.1, −1.4; m/z (ESI) 1205.3908 (M+ + Na. C64H66O20SiNa
requires 1205.3814).
the solution was diluted with CHCl3, and washed with saturated
aqueous NaHCO3, 1 M HCl and water, subsequently. The organic
layer was dried (MgSO4) and concentrated. The residue was
purified on a column of silica gel (hexane–EtOAc 4 : 1 → 3 :
1 → 2 : 1) to yield 13 (1.16 g, 68%) as a colourless syrup; Rf 0.14
(hexane–EtOAc 4 : 1); [a]2D6+ 0.9 (c 1.21, CHCl3); (Found: C,67.77;
H, 5.95; S, 8.73. C42H44O8S2 requires C, 68.08; H, 5.99; S, 8.66%);
dH (270 MHz, CDCl3) 7.76–7.18 (24 H, m), 4.95 (1 H, d, J 11.9),
4.81–4.71 (4 H, m), 4.61 (1 H, d, J 9.9), 4.60 (1 H, d, J 11.5),
4.05 (2 H, m), 3.95–3.88 (2 H, m), 3.59 (1 H, dd, J 2.6 and 9.2),
3.54–3.44 (5 H, m), 2.39 (3 H, s); dC (67.8 MHz, CDCl3) 144.8,
138.7, 138.3, 138.2, 134.0, 133.1, 131.5, 129.8, 128.7, 128.4, 128.3,
128.2, 127.8, 127.7, 127.5, 127.4, 127.1, 87.6, 84.1, 77.3, 77.1, 75.6,
74.3, 73.4, 72.7, 69.7, 68.9, 68.8, 21.6.
2-Trimethylsilylethyl 6-O-triphenylmethyl-b-L-galactopyrano-
side(14). Toasolutionof 5(3.35g, 7.47mmol)inMeOH(80cm3)
was added catalytic amount of NaOMe. After being stirred for 1 h,
the solution was neutralized with Dowex 50W-X8 (H+). The resin
was filtered off, and the filtrate was concentrated. The residue was
dissolved in pyridine (50 cm3), and TrCl (3.12 g, 11.2 mmol) was
added at room temperature. After being stirred overnight at 50 ◦C,
MeOH was added to the solution, and the resulting solution was
concentrated. The residue was purified on a column of silica gel
(hexane–EtOAc 2 : 3) to yield 14 (1.98 g, 50%) as a colourless
syrup; Rf 0.20 (hexane–EtOAc 2 : 3); [a]3D0+ 15.3 (c 1.09, CHCl3);
(Found: C, 68.70; H, 7.24. C30H38O6Si requires C, 68.93; H, 7.33%);
dH (270 MHz, CDCl3) 7.47–7.23 (15 H, m), 4.23 (1 H, d, J 7.6),
4.07–3.97 (2 H, m), 3.65–3.54 (4 H, m), 3.46 (1 H, dd, J 5.6 and
9.4), 3.36 (1 H, dd, J 6.4 and 9.4), 1.02 (2 H, m), 0.01 (9 H, s); dC
(67.8 MHz, CDCl3) 143.5, 128.5, 127.8, 127.1, 102.3, 89.0, 73.6,
73.5, 72.3, 69.1, 67.3, 62.6, 18.4, −1.3;
Phenyl 2,3,4-tri-O-benzyl-6-O-(2-hydroxyethyl)-1-thio-b-D-
galactopyranoside (12). To a solution of phenyl 2,3,4-tri-O-
benzyl-1-thio-b-D-galactopyranoside (11, 2.47 g, 4.55 mmol) in
DMF (30 cm3) was added NaH (55% in oil, 800 mg, 18.3 mmol)
at 0 ◦C. After being stirred for 1 h at 0 ◦C, 2-(2-bromoethoxy)-
tetrahydro-2H-pyrane (2.7 cm3, 18 mmol) was added, and stirred
overnight at room temperature. MeOH was added to the solution
to destroy excess reagents, and diluted with EtOAc. The solution
was washed with brine, and the organic layer was dried (MgSO4)
and concentrated. The residue was purified on a column of silica
gel (hexane–EtOAc 3 : 1 → 1 : 1) to yield THP–ether (2.04 g, 67%)
as a colourless syrup.
The syrup was dissolved in CHCl3–MeOH (2 : 1 v/v, 30 cm3)
and TsOH·H2O (262 mg, 1.52 mmol) was added at 0 ◦C. After
being stirred for 1 h at room temperature, the solution was diluted
with CHCl3, and washed with saturated aqueous NaHCO3. The
organic layer was dried (MgSO4) and concentrated. The residue
was purified on a column of silica gel (hexane–EtOAc 2 : 1 → 3 :
2 → 1 : 1) to yield 12 (1.56 g, 88%) as an amorphous solid.; Rf
0.19 (hexane–EtOAc 2 : 1); [a]2D6 + 1.7 (c 1.1, CHCl3); (Found: C,
71.45; H, 6.37; S, 5.74. C35H38O6S requires C, 71.65; H, 6.53; S,
5.47%); dH (270 MHz, CDCl3) 7.58–7.19 (20 H, m), 4.98 (1 H, d,
J 10.5), 4.81–4.72 (4 H, m), 4.65 (1 H, d, J 9.6), 4.62 (1 H, d, J 11.9),
3.94 (1 H, t, J 9.6 Hz), 3.90 (1 H, d, J 2.6 Hz), 3.65–3.41 (8 H, m);
dC (67.8 MHz, CDCl3) 138.5, 138.12, 138.06, 133.9, 131.5, 128.7,
128.4, 128.2, 128.1, 127.9, 127.7, 127.6, 127.49, 127.48, 127.1, 87.8,
84.2, 77.41, 77.37, 77.2, 75.7, 74.3, 73.5, 72.9, 72.5, 69.9, 61.8.
2-Trimethylsilylethyl 2,3,4-tri-O-benzyl-6-O-triphenylmethyl-b-
L-galactopyranoside (15). To
a solution of 14 (214 mg,
0.410 mmol) in DMF (4◦.0 cm3) was added NaH (55% in oil,
◦
161 mg, 3.69 mmol) at 0 C. After being stirred for 1 h at 0 C,
BnBr (0.3 cm3, 2.5 mmol) was added, and the solution was stirred
for 30 min at room temperature. MeOH was added to the solution,
and the resulting solution was diluted with EtOAc, and washed
with brine. Organic layer was dried (MgSO4) and concentrated.
The residue was purified on a column of silica gel (hexane–EtOAc
20 : 1) to yield 15 (274 mg, 84%) as a colourless syrup.; Rf 0.16
(hexane–EtOAc 20 : 1); [a]2D5 + 2.6 (c 0.9, CHCl3); (Found: C, 76.91;
H, 7.03. C51H56O6Si requires C, 77.24; H, 7.12%); dH (270 MHz,
CDCl3) 7.41–7.11 (30 H, m), 4.92 (1 H, d, J 10.9), 4.83–4.46 (5 H,
m), 4.32 (1 H, d, J 7.9), 4.00 (1 H, dt, J 7.6 and 10.2), 3.85 (1 H, d,
J 2.6) 3.76 (1 H, dd, J 7.9 and 9.6) 3.62–3.44 (3 H, m), 3.36 (1 H, t
J 6.3) 3.20 (1 H, dd, J 6.3 and 8.9) 1.03 (2 H, m), 0.01 (9 H, s); dC
(67.8 MHz, CDCl3) 143.8, 138.6, 128.6, 128.2, 128.1, 128.0, 127.9,
127.8, 127.7, 127.4, 127.1, 126.9, 103.4, 86.8, 82.2, 79.7, 75.1, 74.2,
74.1, 73.6, 73.1, 67.3, 62.8, 18.6, −1.3.
2-Trimethylsilylethyl 2,3,4-tri-O-benzyl-b-L-galactopyranoside
(16). To a solution of 15 (2.47 g, 3.11 mmol) in CHCl3–MeOH
(2:1 v/v, 40 cm3) was added TsOH·H2O (267 mg, 1.55 mmol) at
0 ◦C. After being stirred for 2 h at room temperature, the solution
was diluted with CHCl3, and washed with brine. Aqueous layer
was extracted with CHCl3, and combined organic layer was dried
(MgSO4) and concentrated. The residue was purified on a column
Phenyl 2,3,4-tri-O-benzyl-6-O-{2-(p-toluenesulfonyloxy)ethyl}-
1-thio-b-D-galactopyranoside (13). To a solution of 12 (1.37 g,
2.33 mmol) in pyridine (20 cm3) was added TsCl (1.36 g,
6.98 mmol) at room temperature. After being stirred for 3 h,
686 | Org. Biomol. Chem., 2006, 4, 681–690
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The Royal Society of Chemistry 2006
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