188
G. M. Watt, G.-J. Boons / Carbohydrate Research 339 (2004) 181–193
0
0
4.8. Ethyl 2-O-acetyl-3,4,6-tri-O-benzyl-a-
D
-mannopyr-
-manno-
8.3 Hz, H-300), 4.38 (dd, 1H, J2 –3 10.7 Hz, H-20), 4.31 (m,
4H, H-2, H-3, H-4, and H-40), 4.1100(00m, 3H, H-3000, H-5000,
and H-30000 ), 4.00 (m, 7H, H-4000, H-4 , H-6b000, H-6b0000 , H-
6b0, H-6a0, and CH2CH2TMS), 3.85 (m, 4H, H-300, H-
00
anosyl-(1!6)-[2-O-acetyl-3,4,6-tri-O-benzyl-a-
D
pyranosyl-(1!3)-]-4-O-acetyl-2-O-levulonyl-1-thio-b-
D-
glucopyranoside (15)
50000 , H-6a000, and H-6a0000 ), 3.82 (dd, 1H, J500
3.9, J6a00
–6b
–6b00
Compound 14 (172 mg, 0.14 mmol) was treated with
pyridine (1 mL) and Ac2O (0.5 mL) for 18 h, after which
time the reaction was concentrated in vacuo and the
residue was subjected to flash silica gel column chro-
matography (eluent: 4:1 toluene–EtOAc) to afford 15
11.2 Hz, H-6b00), 3.77 (m, 1H, H-5), 3.72 (dd, 1H, J5
00 –6a00
3.4 Hz, H-6a00), 3.67 (m, 1H, H-6b), 3.52 (m, 3H, H-6a,
H-50 and CH2CH2TMS), 3.46 (m, 1H, H-500), 2.96 (m,
1H, CH2CH2COCH3), 2.72 (m, 2H, CH2CH2COCH3),
2.60 (m, 1H, CH2CH2COCH3), 2.38, 2.35, and 2.18(·2)
(4 · s, 4 · 3H, CH2CH2COCH3 and 3 · COCH3), 0.90
(m, 2H, CH2CH2TMS), and 0.00 (s, 9H, TMS); MAL-
DI-TOF MS: m=z 2335.1 (M+Naþ) and 2351.9
(M+Kþ).
1
(173 mg, 98%) as syrup. H NMR (CDCl3, 500 MHz): d
00 –200
00 –300
2.1, J2
7.40–7.04 (m, 30H, Ar), 5.33 (dd, 1H, J1
2.9 Hz, H-200), 5.11 (dd, 1H, J1 –2 1.5, J2 –3 2.9 Hz, H-20),
5.02 (d, 1H, H-10), 5.01 (dd, 1H, J3ꢀ4 9.3, J4ꢀ5 9.8 Hz, H-
4), 4.94 (dd, 1H, J1–2 9.7, J2–3 9.3 Hz, H-2), 4.84 (d, 1H,
JAB 10.7 Hz, CH2Ph), 4.82 (d, 1H, H-100), 4.80 (d, 1H,
JAB 11.2 Hz, CH2Ph), 4.79 (d, 1H, JAB 11.2 Hz, CH2Ph),
4.70–4.60 (m, 4H, 4 · CH2Ph), 4.54 (d, 1H, JAB 11.2 Hz,
CH2Ph), 4.49 (m, 3H, 3 · CH2Ph), 4.41 (d, 1H, JAB
0
0
0
0
4.10. Trimethylsilylethyl 2-O-acetyl-3,4,6-tri-O-benzyl-a-
D
-mannopyranosyl-(1!6)-[2-O-acetyl-3,4,6-tri-O-benzyl-
a-
-mannopyranosyl-(1!3)-]-2,4-di-O-acetyl-b-
mannopyranosyl-(1!4)-3,6-di-O-benzyl-2-deoxy-2-
phthalamido-b-
-glucopyranosyl-(1!4)-3,6-di-O-benzyl-
2-deoxy-2-phthalamido-b- -glucopyranoside (19)
D
D-
00 –400
10.7 Hz, CH2Ph), 4.33 (d, 1H, H-1), 3.93 (dd, 1H, J3
D
9.3 Hz, H-300), 3.88 (m, 4H, H-3, H-30, H-40, and H-400),
D
3.80 (m, 1H, H-500), 3.75 (m, 4H, H-50, H-6b0, H-6b00, and
00
00 –6a00
H-6b), 3.68 (dd, 1H, J5
1.5 and J6a00
10.3 Hz, H-
A solution of compound 16 (121 mg, 52 lmol) in MeOH
(2 mL) containing hydrazine acetate (12 mg, 124 lmol)
was stirred at room temperature for 1 h, then at 55 ꢁC
for 20 h. The reaction was concentrated in vacuo and
partitioned between CH2Cl2 (20 mL) and water (20 mL),
and the organic phase was dried (MgSO4), filtered and
concentrated in vacuo. Flash silica gel column chro-
matography (eluent: 4:1 toluene–EtOAc) of the residue
–6b
6a00), 3.62 (m, 1H, H-6a0), 3.51 (m, 2H, H-5 and H-6a),
2.59 (m, 6H, CH2CH2COCH3 and SCH2CH3), 2.13,
2.12, 2.11, and 1.97 (4 · s, 4 · 3H, CH2CH2COCH3 and
3 · COCH3) and 1.14 (t, 3H, SCH2CH3); MALDI-TOF
MS: m=z 1335.9 (M+Naþ) and 1352.1 (M+Kþ). Anal.
Calcd for C73H84O19S (1312.5): C, 66.75; H, 6.45.
Found: C, 66.48; H, 6.54.
1
afforded 17 (108 mg, 94%) as a white foam. H NMR
(CDCl3, 500 MHz): d 8.00–6.90 (m, 58H, Ar), 5.46 (d,
4.9. Trimethylsilylethyl 2-O-acetyl-3,4,6-tri-O-benzyl-a-
0000
1H, J1 –2 8.8 Hz, H-10), 5.44 (m, 1H, H-2 ), 5.34 (m, 1H,
0
0
D
-mannopyranosyl-(1!6)-[2-O-acetyl-3,4,6-tri-O-benzyl-
H-2000), 5.22 (dd, 1H, J3
9.8 and J4
9.3 Hz, H-400),
00 –400
00 –500
a-
b-
D
-mannopyranosyl-(1!3)-]-4-O-acetyl-2-O-levulonyl-
-glucopyranosyl-(1!4)-3,6-di-O-benzyl-2-deoxy-2-
D
5.15 (d, 1H, J1–2 7.8 Hz, H-1), 5.11 (d, 1H, H-1000), 5.06
(m, 3H, 3 · CH2Ph), 5.06 (m, 1H, CH2Ph), 5.00 (m, 1H,
CH2Ph), 4.97 (m, 1H, CH2Ph), 4.96 (s, 1H, H-10000 ), 4.89–
4.62 (m, 14H, 14 · CH2Ph), 4.77 (m, 1H, H-100), 4.55 (dd,
phthalamido-b-
D
-glucopyranosyl-(1!4)-3,6-di-O-benzyl-
D
2-deoxy-2-phthalamido-b- -glucopyranoside (16)
1H, J2 –3 10.3, J3 –4 8.8 Hz, H-30), 4.48 (d, 1H, JAB
9.7 Hz, CH2Ph), 4.31 (m, 6H, H-2, H-3, H-4, H-20, H-40,
0
0
0
0
A cooled (0 ꢁC) and stirred solution of 15 (160 mg,
0.12 mmol) and acceptor 8 (155 mg, 0.15 mmol) in dry
CH2Cl2 (2 mL) containing 4 A molecular sieves (0.1 g)
and H-500), 4.20 (dd, 1H, J2000 2.9 and J3
ꢀ
000 –4000
9.3 Hz, H-
-3000
was treated with N-iodosuccinamide (31 mg, 0.13 mmol)
and trimethylsilyl triflate (3 lL, 12 lmol). Stirring was
continued at 0 ꢁC for 15 min, after which time, the
reaction was subjected to the same workup as described
for the preparation of compound 7 to afford 16 (171 mg,
3000), 4.15 (s, 1H, 200-OH), 4.11 (m, 1H, H-6b0), 4.07 (m,
2H, H-4000 and H-30000 ), 4.00 (t, 1H, J 9.3 Hz, H-40000 ), 3.87
(m, 7H, H-50000 , H-6b000, H-6b0000 , H-6b00, H-6a0,
CH2CH2TMS, and H-6a0000 ), 3.72 (m, 3H, H-6b, H-6a00,
and H-6a000), 3.64 (m, 2H, H-200 and H-300), 3.52 (m, 5H,
H-5, H-6a, H-50, H-500, and CH2CH2TMS), 2.38 (·2)
and 2.18 (3 · s, 3 · 3H, 3 · COCH3), 0.90 (m, 2H,
CH2CH2TMS), and 0.00 (s, 9H, TMS); MALDI-TOF
MS: m=z 2237.2 (M+Naþ) and 2253.1 (M+Kþ). The
foregoing compound 17 (108 mg, 49 lmol) in CH2Cl2
(2 mL) was treated with pyridine (130 lL) and triflic
anhydride (110 lL) at 0 ꢁC. The reaction was stirred at
this temperature for 2 h, after which time it was diluted
with CH2Cl2 (50 mL), washed with satd aq NaHCO3
(50 mL), dried (MgSO4), filtered and concentrated in
1
65%) as a white foam. H NMR (CDCl3, 500 MHz): d
8.00–6.90 (m, 58H, Ar), 5.49 (d, 1H, J1 –2 7.8 Hz, H-10),
0
0
5.43 (dd, 1H, J1
2.0, J2
4.9 Hz, H-20000 ), 5.33 (dd,
0000 –20000
0000 –30000
1H, J1
9.8 and J4
2.0, J2
00 –500
2.4 Hz, H-2000), 5.30 (dd, 1H, J3
000 –3000 00 –400
000 –2000
9.3 Hz, H-400), 5.18 (d, 1H, H-1000), 5.17 (m,
2H, H-200 and H-1), 5.11 (d, 1H, JAB 13.2 Hz, CH2Ph),
5.04 (d, 1H, JAB 10.7 Hz, CH2Ph), 5.02 (d, 1H, JAB
11.2 Hz, CH2Ph), 4.96 (m, 1H, CH2Ph), 4.94 (s, 1H, H-
10000 ), 4.83 (m, 3H, 3 · CH2Ph), 4.75–4.56 (m, 13H,
13 · CH2Ph), 4.72 (m, 1H, H-100), 4.45 (dd, 1H, J2
00 –300