W. Zhao, F. Kong / Carbohydrate Research 340 (2005) 1673–1681
1679
(dd, 1H, J2,3 3.2 Hz, J3,4 10.1 Hz, H-3 of Manp), 5.80–
3.12. Methyl 2,3,4-tri-O-benzoyl-b-D-xylopyranosyl-
5.72 (m, 3H, 3H-3 of Xylp), 5.61–5.44 (m, 3H, 3H-2 of
Xylp), 5.54 (m, 1H, H-4 of Xylp), 5.40 (s, 1H, H-1 of
Manp), 5.36 (m, 1H, H-4 of Xylp), 5.30 (d, 1H, J1,2
4.2 Hz, H-1 of Xylp), 5.18 (m, 1H, H-4 of Xylp), 4.90
(d, 1H, J1,2 6.5 Hz, H-1 of Xylp), 4.77 (d, 1H, J1,2
7.0 Hz, H-1 of Xylp), 4.85–3.50 (m, 18H); 13C NMR
(100 MHz, CDCl3): 166.1, 165.8, 165.7, 165.7, 165.6,
165.6, 165.5, 165.4, 165.2, 165.1, 165.0, 164.8, 164.8
(13C, 13COPh), 102.4, 100.8, 100.1, 97.9, 95.0 (5C,
5C-1), 90.7 (–CCl3), 76.0, 75.0, 74.2, 72.3, 72.0, 71.7,
71.7, 71.0, 71.0, 70.7, 69.9, 69.5, 69.0, 68.8, 68.6, 68.1,
64.3, 63.0, 62.8, 62.7, 60.3, 59.5 (C-2 to C-6). Anal.
Calcd for C120H98Cl3NO36: C, 64.43; H, 4.38. Found:
C, 64.21; H, 4.48.
(1!2)-3,4,6-tri-O-benzoyl-a-D-mannopyranosyl-(1!3)-
[2,3,4-tri-O-benzoyl-b-D-xylopyranosyl-(1!2)][2,3,4-tri-
O-benzoyl-b-D-xylopyranosyl-(1!4)]-6-O-benzoyl-a-D-
mannopyranosyl-(1!3)-[2,3,4-tri-O-benzoyl-b-D-xylo-
pyranosyl-(1!4)]-6-O-benzoyl-a-D-mannopyranoside
(15)
To a solution of 14 (1.6 g, 0.6 mmol) in anhyd CH2Cl2
(10 mL) was added anhyd MeOH (40 mL), then AcCl
(3.5 mL) was added to the reaction mixture at 0 ꢁC.
The mixture was stirred at rt for 3 days, TLC (1:1 petro-
leum ether–EtOAc) showed that the starting material
disappeared. The solution was neutralized with Et3N,
then concentrated to dryness. Purification of the residue
by silica gel column chromatography (1:1.4 petroleum
ether–EtOAc) gave 15 (800 mg, 50%) as a foamy solid:
[a]D ꢀ48.9 (c 1.0, CHCl3); 1H NMR (400 MHz, CDCl3):
3.11. Methyl 2,3,4-tri-O-benzoyl-b-D-xylopyranosyl-
(1!2)-3,4,6-tri-O-benzoyl-a-D-mannopyranosyl-(1!3)-
[2,3,4-tri-O-benzoyl-b-D-xylopyranosyl-(1!2)][2,3,4-tri-
O-benzoyl-b-D-xylopyranosyl-(1!4)]-6-O-benzoyl-a-D-
mannopyranosyl-(1!3)-[2,3,4-tri-O-benzoyl-b-D-xylo-
pyranosyl-(1!4)]-2-O-acetyl-6-O-benzoyl-a-D-manno-
pyranoside (14)
d
8.20–6.97 (m, 85H, 17PhH), 6.17 (dd, 1H,
J3,4 = J4,5 = 10.2 Hz, H-4 of Manp), 6.03 (dd, 1H, J2,3
3.2 Hz, J3,4 10.2 Hz, H-3 of Manp), 6.00 (dd, 1H,
J3,4 = J4,5 = 7.0 Hz, H-3 of Xylp), 5.83–5.58 (m, 6H,
3H-3 of Xylp, 2H-2 of Xylp, H-4 of Xylp), 5.53-5.39
(m, 4H, 2H-2 of Xylp, 2H-4 of Xylp), 5.43 (s, 1H, H-1
of Manp), 5.40 (d, 1H, J1,2 4.1 Hz, H-1 of Xylp), 5.22
(d, 1H, J1,2 6.4 Hz, H-1 of Xylp), 5.16 (s, 1H, H-1 of
Manp), 5.15 (m, 1H, H-4 of Xylp), 5.04 (s, 1H, H-1 of
Manp), 4.78 (d, 1H, J1,2 6.4 Hz, H-1 of Xylp), 4.65 (d,
1H, J1,2 7.1 Hz, H-1 of Xylp), 4.85–3.37 (m, 26H), 3.19
(s, 3H, OCH3); 13C NMR (100 MHz, CDCl3): 166.2,
166.0, 165.9, 165.8, 165.7, 165.7, 165.7, 165.5, 165.4,
165.3, 165.3, 165.2, 165.2, 165.1, 164.8, 164.8, 164.6
(17C, 17COPh), 102.4, 102.4, 100.1, 100.1, 100.1, 98.4,
97.0 (7C, 7C-1), 76.3, 76.0, 75.7, 75.5, 73.4, 72.5, 72.2,
71.9, 71.9, 71.8, 71.8, 71.1, 70.8, 70.8, 70.4, 70.1, 70.0,
69.9, 69.3, 69.3, 69.0, 68.6, 68.0, 68.0, 67.9, 63.7, 63.5,
63.2, 63.0, 62.9, 62.8, 60.4, 59.2 (C-2 to C-6), 54.9
(OCH3); Anal. Calcd for C158H134O49: C, 67.38; H,
4.76. Found: C, 67.20; H, 4.85.
To a cooled solution (0 ꢁC) of 12 (2.2 g, 1.0 mmol) and
13 (0.7 g, 1.1 mmol) in anhyd CH2Cl2 (20 mL) was
added TMSOTf (10 lL, 0.07 mmol). The mixture was
stirred at this temperature for 2 h and then quenched
with Et3N (1 drop). The solution was concentrated to
give a residue. Purification of the residue by silica gel
column chromatography (1:1 petroleum ether–EtOAc)
gave 14 (2.2g, 80%) as a foamy solid: [a]D ꢀ17.0 (c
1
1.0, CHCl3); H NMR (400 MHz, CDCl3): d 8.22–6.87
(m, 85H, 17PhH), 6.20 (dd, 1H, J3,4 = J4,5 = 10.0 Hz,
H-4 of Manp), 6.01 (dd, 1H, J2,3 3.3 Hz, J3,4 10.0 Hz,
H-3 of Manp), 6.00 (dd, 1H, J3,4 = J4,5 = 7.2 Hz, H-3
of Xylp), 5.84–5.62 (m, 6H, 3H-3 of Xylp, 2H-2 of Xylp,
H-4 of Xylp), 5.50–5.34 (m, 5H, 2H-2 of Xylp, 3H-4 of
Xylp), 5.43 (s, 1H, H-1 of Manp), 5.38 (d, 1H, J1,2
4.1 Hz, H-1 of Xylp), 5.25 (d, 1H, J1,2 6.5 Hz, H-1 of
Xylp), 5.17 (s, 1H, H-1 of Manp), 5.12 (m, 1H, H-4 of
Xylp), 5.06 (d, 1H, H-2 of Manp), 4.94 (s, 1H, H-1 of
Manp), 4.86 (d, 1H, J1,2 6.2 Hz, H-1 of Xylp), 4.73 (d,
1H, J1,2 7.0 Hz, H-1 of Xylp), 4.85–3.37 (m, 25H), 3.17
(s, 3H, COCH3), 2.03 (s, 3H, OOCCH3); 13C NMR
(100 MHz, CDCl3): 169.8 (COCH3), 166.1, 166.0,
165.9, 165.7, 165.6, 165.6, 165.5, 165.5, 165.4, 165.3,
165.3, 165.2, 165.2, 165.0, 164.8, 164.8, 164.6 (17C,
17COPh), 102.5, 101.6, 100.3, 100.0, 98.8, 98.1, 97.0
(7C, 7C-1), 77.3, 76.6, 76.3, 76.0, 73.3, 72.8, 72.2, 71.9,
71.8, 71.4, 71.3, 71.2, 70.9, 70.6, 70.3, 69.8, 69.6, 69.5,
69.4, 69.0, 68.4, 68.0, 67.9, 63.7, 63.4, 63.1, 63.0, 62.8,
62.6, 62.5, 60.4, 59.0 (C-2 to C-6), 54.9 (OCH3), 20.7
(COCH3); Anal. Calcd for C160H136O50: C, 67.23; H,
4.76. Found: C, 67.11; H, 4.87.
3.13. Methyl b-D-xylopyranosyl-(1!2)-a-D-manno-
pyranosyl-(1!3)-[b-D-xylopyranosyl-(1!2)][b-D-xylo-
pyranosyl-(1!4)]-a-D-mannopyranosyl-(1!3)-[b-D-xylo-
pyranosyl-(1!4)]-a-D-mannopyranoside (16)
Heptasaccharide 14 (200 mg, 0.07 mmol) was dissolved
in a satd methanolic ammonia (10 mL). After stirring
at rt for 72 h, the reaction mixture was concentrated
and purified on a Bio-Gel P2 column (eluent: water),
affording the heptasaccharide 16 (62 mg, 85%) as a foa-
1
my solid: [a]D +31.4 (c 1.0, D2O); H NMR (400 MHz,
CDCl3): d 5.17 (s, 1H, H-1 of Manp), 5.17 (s, 1H, H-1 of
Manp), 4.67 (s, 1H, H-1 of Manp), 4.35 (d, 1H, J1,2
7.8 Hz, H-1 of Xylp), 4.34 (d, 1H, J1,2 7.9 Hz, H-1 of
Xylp), 4.21 (d, 1H, J1,2 7.8 Hz, H-1 of Xylp), 4.18 (d,
1H, J1,2 7.8 Hz, H-1 of Xylp), 4.16–3.07 (m, 30H), 3.30