7 d the reaction was quenched by addition of Et3N (0.5 mL) and
MeOH (0.5 mL), diluted with CH2Cl2, filtered through Celite,
concentrated and purified by flash chromatography (4 : 1→1 : 1,
toluene–EtOAc) to yield the tetrasaccharide 14 (699 mg, 79%)
and the trisaccharide 13 (98 mg, 15%). 14: [a]D −60.9 (c 1.0,
CHCl3); NMR (CDCl3) 13C, d 15.2 (SCH2CH3), 16.1, 16.3 (C-6ꢀꢀ,
6ꢀꢀꢀ), 20.8, 20.9 (COCH3), 24.9 (SCH2CH3), 27.8, 28.3 (C-3ꢀꢀ, 3ꢀꢀꢀ),
61.5, 65.0, 65.6, 65.8, 67.2, 67.7, 69.3, 69.4, 70.1, 70.5, 70.9, 71.3,
71.9, 72.0, 72.5, 73.4, 74.1, 77.9, 80.1, 80.7, 85.4 (C-1-6, 2ꢀ–6ꢀ, 2ꢀꢀ,
4ꢀꢀ–5ꢀꢀ, 2ꢀꢀꢀ, 4ꢀꢀꢀ–5ꢀꢀꢀand 4 CH2Ph), 96.9, 97.7 (C-1ꢀꢀ, 1ꢀꢀꢀ), 100.9 (C-1ꢀ),
126.6–138.1 (aromatic C), 165.8, 165.9 (COPh), 170.2 and 170.5
(COCH3). Anal. calcd for C72H79Cl2N3O19S: C, 62.06; H, 5.71; N,
3.02. Found C, 61.95; H, 5.78; N, 2.83.
concentrated. Pyridine (0.30 mL) and Ac2O (0.10 mL) were added
to a solution of the residue in dry CH2Cl2 (5 mL), stirred for
30 min, concentrated and coevaporated with toluene. Purification
by flash chromatography (1 : 1→1 : 2, pentane–EtOAc) yielded
16 (201 mg, 91%). [a]D −42.4 (c 1.0 CHCl3); NMR (CDCl3) 13C, d
16.2, 16.4 (C-6ꢀꢀ, 6ꢀꢀꢀ), 20.8, 20.8 (COCH3), 23.5 (NHCOCH3), 28.1,
28.5 (C-3ꢀꢀ, 3ꢀꢀꢀ), 35.3 (HOCH2CH2Ar), 58.0, 61.6, 64.9, 65.5, 65.9,
66.9, 67.9, 69.3, 69.7, 70.0, 70.4, 70.7, 71.0, 71.4, 71.5, 72.0, 72.1,
72.9, 73.0, 73.4, 75.1, 76.6, 80.9 (C-2-6, 2ꢀ–6ꢀ, 2ꢀꢀ, 4ꢀꢀ–5ꢀꢀ, 2ꢀꢀꢀ, 4ꢀꢀꢀ–5ꢀꢀꢀ,
HOCH2CH2Ar and 4 CH2Ph), 96.3, 96.6 (C-1ꢀꢀ, 1ꢀꢀꢀ) 99.1, 101.3 (C-
1, 1ꢀ), 118.9–138.1 (aromatic C), 153.5 (NHCOOPh), 165.8, 165.9
(COPh), 170.2, 170.3 and 170.5 (COCH3, NHCOCH3). Anal.
calcd for C88H94Cl2N2O23: C, 65.30; H, 5.85; N, 1.73. Found C,
65.13; H, 5.83; N, 1.78.
2-(4-Benzyloxyamidophenyl)ethanol. 2-(4-Aminophenyl)etha-
nol (3.00 g, 21.9 mmol) and NaOH (892 mg, 22.3 mmol) were
dissolved in H2O (170 mL). Benzyl chloroformate (3.1 mL,
21.7 mmol) was added, with another addition after 30 min (1 mL,
7.0 mmol). The reaction mixture was cooled to 0 ◦C and the
precipitate was collected by filtration. NaOH (487 mg, 12.3 mmol)
and benzyl chloroformate (2 mL, 14.0 mmol) was added to the
mother liquor and after another 40 min the precipitate was col-
lected by filtration. The combined precipitates were recrystallized
from toluene–EtOAc to yield white needles (3.807 g, 64%); mp
124.0 ◦C; NMR (CD3OD) 13C, d 39.5 (HOCH2CH2Ar), 64.1
(HOCH2CH2Ar), 67.3 (CH2Ph), 119.5–138.0 (aromatic C) and
155.6 (CO).
2-(4-Benzyloxyamidophenyl)ethyl (4-O-benzoyl-2-O-p-chloro-
benzyl-3,6-dideoxy-a-L-xylo-hexopyranosyl)-(1→2)-(3-O-benzyl-
b-D-galactopyranosyl)-(1→3)-[4-O-benzoyl-2-O-p-chlorobenzyl-
3,6-dideoxy-a-L-xylo-hexopyranosyl-(1→4)]-2-acetamido-6-O-
benzyl-2-deoxy-b-D-glucopyranoside (17). 16 (141 mg, 87 lmol),
was deacetylated with 1 M NaOMe (4 drops) in MeOH (4 mL)
and CH2Cl2 (1.5 mL). Dowex H+ ion-exchange resin was added
after 1 h, the reaction mixture was filtered, concentrated and
purified by flash chromatography (50 : 1, CHCl3–MeOH) to yield
17 (120 mg, 90%). [a]D −49.4 (c 1.0 CHCl3); NMR (CDCl3) 13C, d
16.2, 16.3 (C-6ꢀꢀ, 6ꢀꢀꢀ), 23.5 (NHCOCH3), 28.1, 28.3 (C-3ꢀꢀ, 3ꢀꢀꢀ), 35.3
(HOCH2CH2Ar), 56.2, 62.3, 65.4, 65.5, 66.2, 66.9, 68.1, 69.4, 69.8,
70.0, 70.5, 71.0, 71.5, 72.2, 72.3, 72.6, 73.3, 73.5, 74.4, 74.7, 74.8 (C-
2-6, 2ꢀ–6ꢀ, 2ꢀꢀ, 4ꢀꢀ–5ꢀꢀ, 2ꢀꢀꢀ, 4ꢀꢀꢀ–5ꢀꢀꢀ, HOCH2CH2Ar and 4 CH2Ph), 95.6,
96.9 (C-1ꢀꢀ, 1ꢀꢀꢀ), 100.1, 101.3 (C-1, 1ꢀ), 118.9–138.1 (aromatic C),
153.5 (NHCOOPh), 165.9, 166.0 (COPh) and 170.2 (NHCOCH3).
2-(4-Benzyloxyamidophenyl)ethyl (4-O-benzoyl-2-O-p-chloro-
benzyl-3,6-dideoxy-a-L-xylo-hexopyranosyl)-(1→2)-(4,6-di-O-
acetyl-3-O-benzyl-b-D-galactopyranosyl)-(1→3)-[4-O-benzoyl-2-
O-p-chlorobenzyl-3,6-dideoxy-a-L-xylo-hexopyranosyl-(1→4)]-2-
azido-6-O-benzyl-2-deoxy-b-D-glucopyranoside (15). 2-(4-Benzyl-
oxyamidophenyl)ethanol (154 mg, 568 lmol), NIS (128 mg,
2-(4-Benzyloxyamidophenyl)ethyl (4-O-benzoyl-2-O-p-chloro-
benzyl-3,6-dideoxy-a-L-xylo-hexopyranosyl)-(1→2)-(4,6-O-cyclic
phosphate-3-O-benzyl-b-D-galactopyranosyl)-(1→3)-[4-O-benzoyl-
2-O-p-chlorobenzyl-3,6-dideoxy-a-L-xylo-hexopyranosyl-(1→4)]-
2-acetamido-6-O-benzyl-2-deoxy-b-D-glucopyranoside, triethyl-
ammonium salt (18). Diol 17 (98 mg, 63.9 lmol) was co-
evaporated three times with pyridine, dissolved in pyridine
(1.2 mL) and added to a 0 ◦C solution of methyl dichlorophosphate
(40 lL, 400 lmol) in pyridine (800 lL). After 10 min the reaction
was allowed to attain room temperature and 70 min later 10%
Et3N in H2O (1 mL) was added. The mixture was diluted with
CHCl3 and washed with 3 × NaCl (aq. satd). The combined water
phases were extracted with CHCl3, and the combined organic
phases were dried (Na2SO4), filtered, concentrated and purified
twice by flash chromatography (6 : 1→3 : 1, EtOAc–MeOH) and
(100 : 1→15 : 1, CHCl3–MeOH) to yield the cyclic phosphate
18 (85 mg, 78%). [a]D −41.9 (c 1.0 CHCl3); NMR (CDCl3)
13C, d 8.6 (Et3N), 16.4, 16.4 (C-6ꢀꢀ, 6ꢀꢀꢀ), 23.1 (NHCOCH3),
28.2, 28.7 (C-3ꢀꢀ, 3ꢀꢀꢀ), 35.4 (HOCH2CH2Ar), 45.7 (Et3N), 57.8,
65.1, 65.7, 66.4, 68.0, 68.2, 69.1, 69.2, 69.4, 69.8, 70.0, 70.4,
70.6, 70.9, 71.1, 71.2, 71.6, 71.8, 72.3, 72.6, 72.7, 73.1, 73.5,
80.7, 80.8 (C-2-6, 2ꢀ–6ꢀ, 2ꢀꢀ, 4ꢀꢀ–5ꢀꢀ, 2ꢀꢀꢀ, 4ꢀꢀꢀ–5ꢀꢀꢀ, HOCH2CH2Ar, 4
CH2Ph), 94.8, 96.0 (C-1ꢀꢀ, 1ꢀꢀꢀ), 99.8, 102.5 (C-1, 1ꢀ), 118.6–138.3
(aromatic C), 153.6 (NHCOOPh), 165.5, 165.6 (COPh) and 169.8
(NHCOCH3); 31P, d −4 (3JPH 22 Hz). MALDI-TOF MS: Calcd
for C84H88Cl2N2Na2O23P ([M + 2Na]+): 1639.47. Found 1639.46.
˚
569 lmol) and 4 A molecular sieves (1.13 g) were added to a
solution of tetrasaccharide 14 (395 mg, 284 lmol) in CH2Cl2
(19 mL). After 50 min stirring under argon the solution was cooled
to 0 ◦C and 12 drops of TMSOTf in CH2Cl2 (2 drops TMSOTf in
1 mL CH2Cl2) were added. After 1 h the reaction mixture was
filtered through Celite, washed with Na2S2O3 (aq. satd), H2O,
dried (Na2SO4), filtered and concentrated. The crude product was
purified by flash chromatography (6 : 1 toluene–acetone) and the a
and b anomers were separated by gravity chromatography (2 : 1 →
1.5 : 1, pentane–EtOAc) to yield 15a (134 mg, 30%) and 15b
(242 mg, 53%). 15b: [a]D −46.3 (c 1.0 CHCl3); NMR (CDCl3) 13C,
d 16.0, 16.3 (C-6ꢀꢀ, 6ꢀꢀꢀ), 20.8, 20.9 (COCH3), 27.9, 28.3 (C-3ꢀꢀ, 3ꢀꢀꢀ),
35.5 (HOCH2CH2Ar), 61.5, 65.0, 65.6, 65.8, 66.9, 67.0, 67.5, 69.3,
69.5, 70.1, 70.5, 70.7, 70.9, 71.4, 72.0, 72.1, 72.6, 73.5, 73.9, 75.7,
76.3, 80.9 (C-2-6, 2ꢀ–6ꢀ, 2ꢀꢀ, 4ꢀꢀ–5ꢀꢀ, 2ꢀꢀꢀ, 4ꢀꢀꢀ–5ꢀꢀꢀ, HOCH2CH2Ar and 4
CH2Ph), 96.8, 97,5 (C-1ꢀꢀ, 1ꢀꢀꢀ), 100.9, 102.1 (C-1, 1ꢀ), 126.6–138.0
(aromatic C), 153.4 (NHCOOPh), 166.8, 166.0 (COPh), 170.2 and
170.5 (COCH3).
2-(4-Benzyloxyamidophenyl)ethyl (4-O-benzoyl-2-O-p-chloro-
benzyl-3,6-dideoxy-a-L-xylo-hexopyranosyl)-(1→2)-(4,6-di-O-
acetyl-3-O-benzyl-b-D-galactopyranosyl)-(1→3)-[4-O-benzoyl-2-
O-p-chlorobenzyl-3,6-dideoxy-a-L-xylo-hexopyranosyl-(1→4)]-2-
acetamido-6-O-benzyl-2-deoxy-b-D-glucopyranoside (16). H2S was
bubbled through a solution of 15b (218 mg, 136 lmol) in pyridine
(3.0 mL) and triethylamine (1.5 mL) for 3 h and the solution was
1240 | Org. Biomol. Chem., 2006, 4, 1236–1241
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