(d, 1H, J 8.9 Hz, OH-3–Gal), 1.54–1.35 (m, 2H, OCHaHbCH2),
1.34–1.21 (m, 2H, CH2CH2N3), 1.20–1.05 (m, 4H, 2 ¥ CH2–
chain); dC (100 MHz, CDCl3) 167.97 (CO), 137.83, 137.30, 134.02,
131.75, 129.22, 128.40, 128.20, 127.98, 127.78, 126.33, 103.93 (C-
1–Gal), 101.31 (PhCH), 98.36 (C-1–GlcN), 83.71 (C-4–GlcN),
74.86 (C-4–Gal), 73.45 (C-5–GlcN), 73.43 (Bn), 72.67 (C-3–Gal),
71.45 (C-2–Gal), 69.80 (C-3–GlcN), 69.51 (OCHaHb), 68.64 (C-
6–GlcN), 66.86 (C-6–Gal), 56.02 (C-2–GlcN), 51.13 (CH2N3),
29.11 (OCHaHbCH2), 28.58 (CH2CH2N3), 26.20 (CH2–chain),
(d, 1H, J 10.4 Hz, H-1–GlcN), 5.29 (dd, 1H, J 3.4, ~1.0 Hz,
H-4–Gal), 5.13 (dd, 1H, J 10.4, 8.1 Hz, H-2–Gal), 4.78 (dd, 1H,
J 10.5, 3.4 Hz, H-3–Gal), 4.62 (high order d, 1H, J 12.1 Hz, Bn),
4.58 (high order d, 1H, J 12.1 Hz, Bn), 4.48 (dd, 1H, J 10.2,
7.7 Hz, H-3–GlcN), 4.38 (d, 1H, J 8.0 Hz, H-1–Gal), 4.33 (dd,
1H, J 10.3, 10.3 Hz, H-2–GlcN), 4.12 (dd, 1H, J 12.0, 7.2 Hz,
H-6a–Gal), 4.08 (dd, 1H, J 12.0, 6.8 Hz, H-6b–Gal), 3.98 (s,
1H, OH-4–GlcN), 3.97–3.89 (m, 2H, H-5–Gal + H-6a–GlcN),
3.75 (dd, 1H, J 10.6, 5.7 Hz, H-6b–GlcN), 3.72–3.60 (m, 2H,
H-5–GlcN + H-4–GlcN), 2.12 (s, 3H, Ac), 2.04 (s, 4H, Ac), 1.87
(s, 3H, Ac), 1.53 (s, 3H, Ac); dC (100 MHz, CDCl3) 170.32 (CO),
170.02 (CO), 169.90 (CO), 168.79 (CO), 168.42 (CO), 166.94
(CO), 138.27, 134.60, 134.11, 133.61, 131.36, 130.52, 128.96,
128.34, 127.58, 127.54, 123.81, 123.75 (Ar), 100.97 (C-1–Gal),
83.34 (C-1–GlcN), 82.88 (C-3–GlcN), 79.78 (C-5–GlcN), 73.47
(Bn), 71.19 (C-5–Gal), 70.76 (C-3–Gal), 69.64 (C-6–GlcN), 69.57
(C-4–GlcN), 68.46 (C-2–Gal), 66.75 (C-4–Gal), 61.43 (C-6–Gal),
53.84 (C-2–GlcN), 20.53 (Ac), 20.49 (Ac), 20.36 (Ac), 19.87 (Ac);
m/z (ESI-HRMS) calcd for [C41H42NO15SCl + Na]+ 878.1856,
found 878.1854.
25.40 (CH2–chain); m/z (ESI-HRMS) calcd for [C40H46N4O12
+
Na]+ 797.3004, found 797.3005.
p-Chlorophenyl
2,3,4,6-tetra-O-acetyl-b-D-galactopyranosyl-
(1→3)-4,6-O-benzylidene-2-deoxy-2-phthalimido-1-thio-b-D-glu-
copyranoside (7). Imidate 10 (2.44 g, 4.95 mmol) and alcohol 14
(1.04 g, 1.98 mmol) were dissolved anhydrous CH2Cl2 (10 mL)
˚
under Ar and 4 A molecular sieves (2.5 g) were added. After
stirring at rt for 1 h, TMSOTf (35 mL) was added dropwise. After
2 h, the reaction was neutralized with Et3N (1.0 mL). The mixture
was diluted with EtOAc (50 mL) and the insoluble molecular
sieves were removed by filtration. After concentration, the residue
was purified by chromatography on silica gel using a gradient of
AcOEt–hexane (30% → 40%) to afford the desired disaccharide
7 (1.2 g, 75% yield) as a white solid (Found: C, 57.20; H, 5.08; N,
1.68%. C41H40NO15SCl requires C, 57.64; H, 4.72; N, 1.64%); [a]D
+33.3 (c 0.2, CHCl3); dH (400 MHz, CDCl3) 7.98–7.73 (m, 4H,
Phth), 7.50–7.43 (m, 2H, Ph), 7.40–7.32 (m, 3H, Ph), 7.29 (d, 2H, J
8.5 Hz, SPhCl), 7.21 (d, 2H, J 8.5 Hz, SPhCl), 5.55 (s, 1H, PhCH),
5.51 (d, 1H, J 10.6 Hz, H-1–GlcN), 5.18 (dd, 1H, J 2.9, ~1.0 Hz,
H-4–Gal), 4.96 (dd, 1H, J 10.3, 8.0 Hz, H-2–Gal), 4.76–4.68
(m, 2H, H-3–Gal + H-3–GlcN), 4.54 (d, 1H, J 8.0, H-1–Gal),
4.41–4.32 (m, 2H, H-2–GlcN + H-6a–GlcN), 4.02 (dd, 1H, J 11.0,
8.3 Hz, H-6a–Gal), 3.87–3.74 (m, 3H, H-6b–Gal + H-6b–GlcN +
H-4–GlcN), 3.70 (ddd, 1H, J 9.6, 9.6, 4.6 Hz, H-5–GlcN), 3.45
(ddd, 1H, J 7.8, 6.2, ~1 Hz, H-5–Gal), 2.05 (s, 3H, Ac), 1.89 (s,
3H, Ac), 1.82 (s, 3H, Ac), 1.51 (s, 3H, Ac); dC (100 MHz, CDCl3)
170.21 (CO), 170.00 (CO), 169.97 (CO), 168.81 (CO), 136.92,
134.73, 134.54, 129.45, 129.34, 129.13, 128.38, 126.04 (Ar), 101.50
(PhCH), 100.38 (C-1–Gal), 83.84 (C-1–GlcN), 80.69 (C-4–GlcN),
76.50 (C-3–Gal), 70.95 (C-3–GlcN), 70.60 (C-5–GlcN), 70.31
(C-5–Gal), 69.19 (C-2–Gal), 68.51 (C-6–GlcN), 66.59 (C-4–Gal),
60.74 (C-6–Gal), 54.28 (C-2–GlcN), 20.59 (Ac), 20.53 (Ac), 20.41
(Ac), 20.03 (Ac); m/z (ESI-HRMS) calcd for [C41H40NO15SCl +
Na]+ 876.1699, found 876.1695.
p-Chlorophenyl
(1→3)-[2,3,4-tri-O-benzyl-a-L-fucopyranosyl–(1→4)]-6-O-benzyl-
2-deoxy-2-phthalimido-1-thio-b-D-glucopyranoside (8). The
2,3,4,6-tetra-O-acetyl-b-D-galactopyranosyl-
disaccharide 9 (155.8 mg, 0.20 mmol) and thiofucoside 15
˚
(331.5 mg, 0.59 mmol) were stirred with 4 A molecular sieves
(400 mg) in anhydrous CH2Cl2 (2 mL) under Ar for 1 h. After
cooling to -30◦ C, NIS (96.3 mg, 0.41 mmol, 2.1 equiv.) was
added, and after 5 mins, TfOH (5.0 mL) was added dropwise.
The reaction was slowly warmed up to -10◦ C within 1 h, and
quenched with Et3N (0.5 mL). The reaction mixture was worked
up similarily as 22 and compound 8 (187.2 mg) was obtained by
column chromatography on silica gel using 30% EtOAc–hexane
as eluent in 84% yield. Some starting material recovered (10 mg)
was recovered. [a]D -16.8 (c 0.6, CHCl3); dH (400 MHz, CDCl3)
7.96–7.87 (m, 2H, Phth), 7.87–7.79 (m, 2H, Phth), 7.52–7.17 (m,
22H), 7.11 (d, 2H, J 8.1 Hz, SPhCl), 5.30 (d, 1H, J 10.4 Hz,
H-1–GlcNAc), 5.21 (dd, 1H, J 2.7, 1.0 Hz, H-4–Gal), 5.16 (d,
1H, J 3.8 Hz, H-1–Fuc), 5.04–4.97 (m, 2H, Bn + H-2–Gal),
4.93 (d, 1H, J 11.6 Hz, Bn), 4.91–4.69 (m, 6H, H-3–Gal +
H-5–Fuc + 4 ¥ Bn), 4.45–4.35 (m, 3H, H-2–Fuc + 2 ¥ Bn), 4.32
(dd, 1H, J 10.3, 10.3 Hz, H-2–GlcN), 4.28–4.16 (m, 3H, H-6a–
Gal + H-3–GlcN + H-1–Gal), 4.04–3.93 (m, 4H, H-6b–Gal +
H-6a–GlcN + H-3–Fuc + H-4–GlcN), 3.78 (br, 1H, H-4–Fuc),
3.74–3.59 (m, 3H, H-6b–GlcN +H-5–Gal + H5–GlcN), 2.03 (s,
3H, Ac), 2.00 (s, 3H, Ac), 1.86 (s, 3H, Ac), 1.75 (s, 3H, Ac), 1.32
(d, 3H, J 6.5 Hz, H-6–Fuc); dC (100 MHz, CDCl3) 170.20 (CO),
170.07 (CO), 169.90 (CO), 169.42 (CO), 138.91, 138.82, 138.47,
138.35, 135.01, 134.48, 134.44, 129.96, 129.12, 128.86, 128.61,
128.58, 128.52, 128.51, 128.44, 128.00, 127.81, 127.72, 127.68,
127.52, 127.14, 123.90 (Ar), 100.76 (C-1–Gal), 98.08 (C-1–Fuc),
83.20 (C-1–GlcN), 80.99 (C-4–GlcN), 80.18 (C-5–GlcN), 76.56
(C-4–Fuc), 75.85 (C-3–Gal), 75.72 (C-3–GlcN), 75.12 (Bn), 74.11
(Bn), 73.24 (Bn), 72.92 (C-3–Fuc), 72.41 (Bn), 71.19 (C-2–Fuc),
70.47 (C-5–Gal), 67.92 (C-2–Gal), 67.67 (C-6–GlcN), 66.58
(C-5–Fuc), 66.44 (C-4–Gal), 59.88 (C-6–Gal), 55.49 (C-2–GlcN),
20.74 (Ac), 20.61 (Ac), 20.59 (2 ¥ Ac), 17.11 (C-6–Fuc); m/z
(ESI-HRMS) calcd for [C68H70NO19SCl + Na]+ 1294.3844, found
1294.3844.
p-Chlorophenyl
2,3,4,6-tetra-O-acetyl-b-D-galactopyranosyl-
(1→3)-6-O-benzyl-2-deoxy-2-phthalimido-1-thio-b-D-glucopyrano-
side (9). The disaccharide 7 (884 mg, 1.04 mmol) was dissolved
in anhydrous CH2Cl2 (17 mL) and the mixture was cooled
to 0 ◦C. After the addition of Et3SiH (1.65 mL, 10.3 mmol),
BF3·Et2O (239 mL, 1.9 mmol) was added dropwise. The reaction
was continues at 0 ◦C for 1 h, and subsequently at rt for another
1 h. Et3N (2.0 mL) was added to quench the reaction. After
concentration, the mixture was purified by chromatography on
silica gel using 35% AcOEt–hexane as eluent to give the desired
disaccharide 9 (802 mg, 97.8% yield) as a white solid (Found: C,
57.24; H, 5.11; N, 1.63%. C41H42NO15SCl requires C, 57.51; H,
4.94; N, 1.64%); [a]D +26.6 (c 1.2, CHCl3); dH (400 MHz, CDCl3)
7.92–7.86 (m, 2H, Phth), 7.84–7.78 (m, 2H, Phth), 7.40–7.29 (m,
7H, 5 ¥ Bn + 2 ¥ SPhCl), 7.10 (d, 2H, J 8.2 Hz, SPhCl), 5.39
134 | Org. Biomol. Chem., 2010, 8, 128–136
This journal is
The Royal Society of Chemistry 2010
©