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J. K. Maity et al. / Carbohydrate Research 342 (2007) 2511–2521
4.1.7. 1-(2-O-Acetyl-3,6-anhydro-5-O-benzyl-b-D-gluco-
furanosyl)uracil (11). Compound 10 (2.5 g, 8.56 mmol)
was treated with 30 mL of 4% H2SO4 in aqueous
CH3CN (75%). The residue obtained after solvent
removal was acetylated with pyridine (20 mL) and
Ac2O (2.5 mL) mixture to give a diacetate mixture
(2.25 g), which was subjected to the protocol described
for preparation of 8 utilizing uracil (2.11 g, 18.83 mmol),
hexamethyldisilazane (20 mL), TMSCl (two drops),
TMSOTf (1.46 mL, 8.04 mmol), and CH3CN (25 mL)
chloride (0.79 mL, 10.25 mmol) and the mixture was
stirred for 30 min. The temperature was raised to
25 ꢁC and the solution was stirred for 1.5 h. The solvent
was evaporated in vacuo and the crude residue was ex-
tracted CH3CO2Et (3 · 30 mL). The combined extract
was washed with water (2 · 30 mL), dried (Na2SO4)
and concentrated in vacuo. The crude product was puri-
fied by silica gel column chromatography using
CH3CO2Et–petroleum ether (80:20) as eluent to afford
25
13 (895 mg, 89%) as a yellow foamy solid: ½aꢂD +111.3
25
to get 11 (1.5 g, 58%) as a foamy solid: ½aꢂD +102.6 (c
(c 0.22, MeOH); IR (KBr): mmax 3235, 1699, 1678,
0.81, CH3OH); IR (KBr): mmax 3198, 1749, 1693, 1456,
1630, 1447, 1406, 1387 1358, 1280, 1176, 1128, 1034,
1379, 1274, 1229, 1114, 1053, 816, 751, 700, 649, 606,
974, 877 cmꢁ1 1H NMR (CDCl3, 300 MHz): d 3.27
;
565 cmꢁ1
;
1H NMR (CDCl3, 300 MHz): d 2.11 (s,
(s, 3H), 3.89 (dd, 1H, J = 4.5, 10.0 Hz), 3.99 (dd,
1H, J = 6.8, 10.0 Hz), 4.35–4.41 (m, 1H), 4.56 (d, 1H,
J = 11.0 Hz), 4.59 (d, 1H, J = 3.6 Hz), 4.74 (d, 1H,
J = 11.0 Hz), 4.99 (t, 1H, J = 4.2 Hz), 5.19 (s, 1H),
5.62 (d, 1H, J = 8.1 Hz), 6.01 (d, 1H, J = 3.6 Hz),
7.36–7.41 (m, 5H), 7.98 (d, 1H, J = 8.1 Hz), 9.73 (br s,
1H); 13C NMR (CDCl3, 75 MHz): d 38.6 (CH3), 72.8
(CH2), 73.0 (CH2), 79.1 (CH), 84.0 (CH), 84.8 (CH),
85.8 (CH), 92.0 (CH), 102.2 (CH), 128.1 (2 · CH),
128.4 (CH), 128.7 (2 · CH), 136.7 (C), 139.6 (CH),
150.9 (C), 163.5 (C); ESIMS, m/z: 447 (M+Na)+. Anal.
Calcd for C18H20N2O8S: C, 50.94, H, 4.75; N, 6.60.
Found C, 50.66; H, 4.58; N, 6.38.
3H), 3.91–4.02 (m, 2H), 4.26 (dd, 1H, J = 5.8,
10.8 Hz), 4.48 (d, 1H, J = 3.0 Hz), 4.56 (d, 1H,
J = 11.5 Hz), 4.70 (d, 1H, J = 11.5 Hz), 4.79 (t, 1H,
J = 4.5 Hz), 5.23 (d, 1H, J = 1.5 Hz), 5.63 (d, 1H,
J = 7.8 Hz), 6.18 (d, 1H, J = 3.3 Hz), 7.35 (br s, 5H),
7.71 (d, 1H, J = 8.1 Hz), 8.99 (br s, 1H); 13C NMR
(CDCl3, 75 MHz): d 20.9 (CH3), 69.6 (CH2), 72.1
(CH2), 78.9 (CH), 80.3 (CH), 82.2 (CH), 85.8 (CH),
91.2 (CH), 103.4 (CH), 128.5 (2 · CH), 128.7 (CH),
129.1 (2 · CH), 137.3 (C), 140.5 (CH), 150.6 (C), 163.3
(C), 169.9 (C); ESIMS, m/z: 411 (M+Na)+. Anal. Calcd
for C19H20N2O7: C, 58.76; H, 5.19; N, 7.21. Found: C,
58.48; H, 5.14; N, 6.95.
4.1.10.
2,20-Anhydro-1-(3,6-anhydro-5-O-benzyl-b-D-
4.1.8.
1-(3,6-Anhydro-5-O-benzyl-b-D-glucofuranosyl)
mannofuranosyl)-2-hydroxy-(1H)-pyrimidin-4-one (14).
To a solution of 13 (600 mg, 1.42 mmol) in CH3CN
(15 mL) was added DBU (0.32 mL, 2.12 mmol), and
the mixture was stirred at room temperature for 10 h
under N2. The solvent was evaporated under reduced
pressure and the crude product was chromatographed
on silica gel using CH3CO2Et–MeOH (92:8) as eluent
uracil (12). To a solution of 11 (1.40 g, 3.60 mmol) in
dry MeOH (20 mL) was added K2CO3 (622 mg,
4.50 mmol), and the mixture was stirred at room tem-
perature for 30 min. Usual workup and purification by
column chromatography on silica gel using with
CH3CO2Et–MeOH (95:5) as eluent furnished 12
25
25
(1.22 g, 98%) as a foamy solid: ½aꢂD +107.5 (c 0.81,
to furnish 14 (415 mg, 89%) as a white solid: ½aꢂD
CH3OH); IR (KBr): mmax 3383, 1688, 1463, 1391, 1274,
+99.8 (c 0.21, MeOH); IR (KBr): mmax 1655, 1620,
1211, 1111, 1063, 1024, 814 cmꢁ1; H NMR (C5D5N,
1530, 1478, 1347, 1261, 1236, 1139, 938, 831 cmꢁ1; H
1
1
300 MHz): d 4.03 (dd, 1H, J = 6.7, 9.4 Hz), 4.09 (dd,
1H, J = 5.4, 9.4 Hz), 4.33 (dd, 1H, J = 5.2, 11.4 Hz),
4.56 (d, 1H, J = 11.4 Hz), 4.74 (1H, unresolved), 4.79
(d, 1H, J = 11.4 Hz), 4.95 (br s, 1H), 5.09 (t, 1H,
J = 4.3 Hz), 5.71 (d, 1H, J = 8.1 Hz), 6.64 (d, 1H,
J = 2.7 Hz), 7.25–7.37 (m, 3H), 7.46 (d, 2H, J =
7.2 Hz), 8.18 (d, 1H, J = 8.1 Hz), 8.27 (br s, 1H), 13.27
(br s, 1H); 13C NMR (C5D5N, 75 MHz): d 73.9 (CH2),
74.1 (CH2), 81.2 (CH), 81.6 (CH), 84.4 (CH), 90.9
(CH), 96.3 (CH), 103.9 (CH), 129.8 (CH), 130.0
(2 · CH), 130.5 (2 · CH) 140.1 (C), 142.5 (CH), 153.7
(C), 166.0 (C); ESIMS, m/z: 369 (M+Na)+. Anal. Calcd
for C17H18N2O6: C, 58.96; H, 5.24; N, 8.09. Found: C,
58.90; H, 5.21; N, 7.94.
NMR (C5D5N, 300 MHz): d 3.69 (t-like, 1H, J = 7.0,
8.5 Hz), 3.95 (t-like, 1H, J = 6.4, 8.8 Hz), 4.09 (apparent
dd, 1H, J = 5.6, 13.3 Hz), 4.49 (d, 1H, J = 12.0 Hz),
4.62 (d, 1H, J = 12.0 Hz), 4.99–5.04 (2H, merged with
solvent), 5.65 (t, 1H, J = 5.8 Hz), 6.10 (d, 1H, J =
7.4 Hz), 6.50 (d, 1H, J = 5.8 Hz), 7.30–7.35 (m, 5H),
7.75 (d, 1H, J = 7.4 Hz); 13C NMR (C5D5N, 75 MHz):
d 72.2 (CH2), 72.7 (CH2), 78.3 (CH), 81.4 (CH), 82.4
(CH), 84.8 (CH), 92.8 (CH), 109.6 (CH), 128.0 (CH),
128.1 (2 · CH), 128.7 (2 · CH), 136.1 (CH), 138.4 (C),
161.3 (C), 172.1 (C); ESIMS, m/z: 351 (M+Na)+. Anal.
Calcd for C17H16N2O5: C, 62.19; H, 4.91; N, 8.53.
Found C, 62.02; H, 4.81; N, 8.38.
4.1.11. 1-(3,6-Anhydro-2-azido-5-O-benzyl-2-deoxy-b-D-
glucofuranosyl)uracil (15). Preparation of 15 from 14:
A mixture of 14 (306 mg, 0.93 mmol), NaN3 (182 mg,
2.79 mmol), 15-crown-5 (0.56 mL, 2.79 mmol), and
4.1.9. 1-(3,6-Anhydro-5-O-benzyl-2-O-mesyl-b-D-gluco-
furanosyl)uracil (13). To a solution of 12 (825 mg,
2.38 mmol) in pyridine (20 mL) at 0 ꢁC was added mesyl