I. Damager et al. / Carbohydrate Research 339 (2004) 1727–1737
1735
4.00–4.21 (m, 3H, H-6b, H-5, H-60b), 3.95 (m, 1H, J3;4
9.1 Hz, H-4), 3.76 (m, 1H, H-50), 3.36 (s, 3H, OCH3),
C31H38O21N2+K: 813.7. Found: 813.1. Anal. Calcd for
C31H38O21N2 (774.64): C, 48.07; H, 4.94; N, 3.62.
Found: C, 47.97; H, 4.62; N, 4.02.
3.26 (t, 1H, J3 ;4 9.7 Hz, H-40), 2.07, 2.07, 2.02, 2.02,
1.98, 1.95, 1.95 (7s, 21H, 7COCH3). 13C NMR: (CDCl3,
75 MHz): For a-isomer: d 170.7, 170.4, 170.3, 169.9,
169.9, 169.5, 168.8 (7C@O), 95.8 (C-10), 88.7 (C-1a),
77.2, 72.3, 72.2, 71.1, 70.3, 70.1, 69.7, 69.7 (C-2, C-3, C-
4, C-5, C-20, C-30, C-40, C-50), 62.4, 62.1 (C-6, C-60), 60.1
(OCH3), 20.8, 20.7, 20.7, 20.6, 20.6, 20.5, 20.2
(7COCH3). For b-isomer: 91.2 (C-1b). MALDI-TOF;
Calcd for C27H38O18+Na: 673.6. Found: 673.5.
C27H38O18+K: 689.7. Found: 689.4. Anal. Calcd for
C27H38O18 (650.59): C, 49.85; H, 5.89. Found: C, 49.88;
H, 5.91.
0
0
3.1.12. 2,4-Dinitrophenyl 2,20,3,30,6,60-hexa-O-acetyl-40-
O-methyl-a-maltoside (16). To a soln of compound 15
(600 mg, 0.78 mmol) in DMF (15 mL), anhyd K2CO3
(552 mg, 4.00 mmol) was added and the reaction mixture
was stirred overnight in the dark. The DMF was evap-
orated under diminished pressure and the residue was
dissolved in CHCl3 (15 mL), washed with satd aq
NaHCO3 (2 · 10 mL), water (10 mL) and brine (10 mL),
and then dried. The solvent was evaporated under re-
duced pressure and 16 was crystallised from EtOAc–
petroleum ether in 63% (375 mg) as the pure a-anomer.
1H NMR data (CDCl3, 300 MHz): d 8.71 (d, 1H, H–Ar),
8.42 (dd, 1H, H–Ar), 7.50 (d, 1H, H–Ar), 5.84 (d, 1H,
J1;2 3.6 Hz, H-1), 5.67 (dd, 1H, J2;3 9.7 Hz, J3;4 8.3 Hz, H-
3.1.11. 2,4-Dinitrophenyl-2,20,3,30,6,60-hexa-O-acetyl-40-
O-methyl-b-maltoside (15). A soln of compound 14
(0.58 g, 0.89 mmol) in DMF (6 mL) was heated to 50 °C
and hydrazineÁacetate (92 mg, 0.98 mmol) was added.
The reaction mixture was cooled to room temperature
and stirred for 2 h. The DMF was evaporated under
diminished pressure and the residue was dissolved in
CHCl3 (5 mL), then washed with satd aq NaHCO3
(2 · 3 mL), H2O (3 mL) and brine (3 mL), and then
dried. The solvent was evaporated under diminished
pressure to afford 2,20,3,30,6,60-hexa-O-acetyl-40-O-me-
thyl-maltose as a white foam, which was dissolved in dry
DMF (5 mL). DNFB (0.18 g, 0.97 mmol) and DABCO
(100 mg, 0.89 mmol) were added and the reaction mix-
ture was stirred overnight in the dark. The DMF was
then evaporated under diminished pressure and the
residue was dissolved in CHCl3 (5 mL), washed with
satd aq NaHCO3 (2 · 3 mL), water (3 mL) and brine
(3 mL), and then dried. The solvent was evaporated
under reduced pressure and the residue was chromato-
graphed on Silica Gel with petroleum ether–EtOAc as
eluent (1:1) to give 15 as a white solid in 87% yield
3), 5.36 (d, 1H, J1 ;2 4.0 Hz, H-10), 5.32 (dd, 1H, J2 ;3
0
0
0
0
10.4 Hz, J3 ;4 9.5 Hz, H-30), 4.90 (dd, 1H, H-2), 4.76 (dd,
0
0
1H, H-20), 4.45 (dd, 1H, J5;6a 2.0 Hz, J6a;6b 12.2 Hz, H-
6a), 4.32 (dd, 1H, J5 ;6a 2.2 Hz, J6a0;6b 12.2 Hz, H-6a0),
0
0
0
4.22 (dd, 1H, J50;6b 3.9 Hz, H-6b0), 4.20 (dd, 1H, J5;6b
4.0 Hz, H-6b), 4.10 (m, 1H, H-5), 4.06 (t, 1H, H-4), 3.77
0
(m, 1H, H-50), 3.40 (s, 3H, OCH3), 3.30 (t, 1H, H-40),
2.12, 2.10, 2.08, 2.06, 2.05, 2.03 (6s, 18H, 6COCH3). 13
C
NMR: (CDCl3, 75 MHz): d 170.7, 170.4, 170.4, 170.4,
169.8, 169.8 (6C@O), 153.6, 142.0, 140.3, 128.6, 121.7,
118.1 (6Ar–C), 96.2 (C-1), 95.6 (C-10), 71.7, 71.5, 71.0,
70.3, 70.2, 70.2, 70.2, 69.8 (C-2, C-3, C-4, C-5, C-20, C-
30, C-40, C-50), 62.2, 62.0 (C-6, C-60), 60.1 (OCH3), 20.8,
20.8, 20.8, 20.8, 20.6, 20.4 (6COCH3). EISMS: Calcd for
C31H38O21N2+NH3: 791.7. Found: 792.1. Calcd for
C31H38O21N2+Na: 797.6. Found: 797.1. Calcd for
C31H38O21N2+K: 813.7. Found: 813.1. Anal. Calcd for
C31H38O21N2 (774.64): C, 48.07; H, 4.94; N, 3.62.
Found: C, 47.97; H, 4.62; N, 4.02.
1
(604 mg). H NMR data (CDCl3, 300 MHz): d 8.68 (d,
1H, H–Ar), 8.42 (dd, 1H, H–Ar), 7.45 (d, 1H, H–Ar),
3.1.13. 2,4-Dinitrophenyl 40-O-methyl-a-maltoside (17).
A soln of compound 16 (199 mg, 0.26 mmol) in MeOH
(10 mL) was cooled to 0 °C and acetyl chloride (0.5 mL)
was added slowly while stirring. The reaction mixture
was left stirring at 4 °C for 48 h, then the solvent was
evaporated under reduced pressure and the residue was
chromatographed on Silica Gel using EtOAc–MeOH–
AcOH (17:2:1) as eluent. The remaining solid was pre-
cipitated from MeOH–diethyl ether to give 17 in 60%
yield (80 mg). 1H NMR data (CD3OD, 300 MHz): d 8.72
(d, 1H, J 2.8 Hz, H–Ar), 8.43 (dd, 1H, J 2.8 Hz, J
9.4 Hz, H–Ar), 7.65 (d, 1H, J 9.4 Hz, H–Ar), 5.88 (d,
5.34 (dd, 1H, J2 ;3 10.7 Hz, J3 ;4 9.7 Hz, H-30), 5.33 (d,
0
0
0
0
1H, J1;2 6.8 Hz, H-1), 5.33 (d, 1H, J1 ;2 4.0 Hz, H-10), 5.27
(t, 1H, J2;3 8.1 Hz, H-3), 5.12 (dd, 1H, H-2), 4.76 (dd,
1H, H-20), 4.53 (dd, 1H, J5;6a 2.7 Hz, J6a;6b 12.3 Hz, H-
0
0
6a), 4.32 (dd, 1H, J5 ;6a 2.2 Hz, J6a0;6b 12.3 Hz, H-6a0),
0
0
0
4.24 (dd, 1H, J50;6b 4.2 Hz, H-6b0), 4.20 (dd, 1H, J5;6b
4.9 Hz, H-6b), 4.10 (t, 1H, H-4), 4.06 (m, 1H, H-5), 3.81
0
(m, 1H, H-50), 3.41 (s, 3H, OCH3), 3.30 (t, 1H, H-40),
2.11, 2.09, 2.07, 2.05, 2.04, 2.03 (6s, 18H, 6COCH3). 13
C
NMR: (CDCl3, 75 MHz): d 170.5, 170.4, 170.1, 170.0,
169.8, 169.3 (6C@O), 153.5, 142.3, 140.3, 128.6, 121.4,
118.6 (6Ar–C), 98.7 (C-1), 95.9 (C-10), 74.3, 73.0, 72.3,
71.0, 70.1, 69.2, 68.7, 68.0 (C-2, C-3, C-4, C-5, C-20, C-
30, C-40, C-50), 62.3, 61.5 (C-6, C-60), 60.1 (OCH3), 20.8,
20.6, 20.6, 20.6, 20.6, 20.5 (6COCH3). EISMS: Calcd
for C31H38O21N2+NH3: 791.7. Found: 792.1. Calcd for
C31H38O21N2+Na: 797.6. Found: 797.2. Calcd for
1H, J1;2 3.5 Hz, H-1), 5.12 (d, 1H, J1 ;2 3.8 Hz, H-10),
4.09–3.40 (m, 11H, H-2, H-3, H-4, H-5, H-6a, H-6b, H-
20, H-30, H-50, H-6a0, H-6b0), 3.25 (s, 3H, OCH3), 3.01 (t,
1H, J3;4 9.2 Hz, H-40). 13C NMR (CD3OD, 75 MHz): d
155.4, 142.5, 140.3, 131.3, 123.3, 118.8 (6Ar–C), 101.0
(C-10), 98.8 (C-1), 80.5, 77.8, 74.5, 74.0, 73.7, 73.2, 73.1,
0
0