372
S.-C. Hung et al. / Carbohydrate Research 331 (2001) 369–374
1
3
centrated in vacuo, and the residue was
purified by flash chromatography (1:20
EtOAc–hexane) to afford 7 as a colourless oil
Me-6); C NMR (100 MHz, CDCl ): l 169.80
3
(C), 168.99 (C), 168.83 (C), 168.58 (C), 90.78
(CH), 68.88 (CH), 67.42 (CH), 66.44 (CH),
64.80 (CH), 20.73 (CH ), 20.53 (CH ), 15.29
(CH ). Anal. Calc. for C H O : C, 50.60; H,
6.07. Found: C, 50.37; H, 5.90%. 8b: [h]D
+16.9° (c 1.0, CHCl ); IR (CHCl ): 2989,
2
5
(
1.46 g, 87%): [h] +15.4° (c 1.0, CHCl ); IR
D
3
3
3
(
1
5
CHCl ): 2990, 2938, 1374, 1204, 1164, 1090,
3
3
14 20
9
−
1
1
25
016 cm ; H NMR (400 MHz, CDCl ): l
3
.89 (d, J1,2 3.6 Hz, 1 H, H-1), 4.43 (d, 1 H,
3
3
−
1
1
H-2), 4.12 (d, J3,4 1.5 Hz, 1 H, H-3), 4.07 (dq,
J5,6 6.5 Hz, 1 H, H-5), 3.78 (t, J4,5 1.5 Hz, 1 H,
H-4), 1.42 (s, 3 H, Me), 1.37 (s, 3 H, Me), 1.32
1751, 1432, 1371, 1221, 1052, 645 cm ; H
NMR (400 MHz, CDCl ): l 6.03 (d, J 2.1
3
1,2
Hz, 1 H, H-1), 5.18 (t, J3,4 4.3 Hz, 1 H, H-3),
4.96 (dd, J2,3 4.3 Hz, 1 H, H-2), 4.76 (dd, J4,5
2.6 Hz, 1 H, H-4), 4.22 (dq, J5,6 6.6 Hz, 1 H,
H-5), 2.11 (s, 3 H, Ac), 2.10 (s, 3 H, Ac), 2.10
(s, 3 H, Ac), 2.08 (s, 3 H, Ac), 1.26 (d, 3 H,
(
s, 3 H, Me), 1.27 (d, 3 H, Me-6), 1.25 (s, 3 H,
13
Me); C NMR (75 MHz, CDCl ): l 111.44
3
(
(
C), 104.86 (CH), 97.90 (C), 84.19 (CH), 73.85
CH), 73.69 (CH), 64.48 (CH), 29.30 (CH3),
1
3
2
6.62 (CH ), 26.07 (CH ), 19.09 (CH ), 17.56
Me-6); C NMR (100 MHz, CDCl ): l 169.56
3
3
3
3
+
(
2
CH ); HRFABMS: Calc. for C H O (MH )
45.1388; Found: m/z 245.1381. Anal. Calc.
(C), 169.35 (C), 168.61 (C), 168.41 (C), 89.91
(CH), 70.37 (CH), 67.95 (CH), 67.53 (CH),
65.99 (CH), 20.66 (CH ), 20.52 (CH ), 20.49
3
12 21
5
for C H O : C, 59.00; H, 8.25. Found: C,
5
1
2
20
5
3
3
9.07; H, 8.20%.
,2,3,4-Tetra-O-acetyl-6-deoxy-
(CH ), 20.42 (CH ), 15.98 (CH ). Anal. Calc.
3
3
3
1
L
-idopyran-
for C H O : C, 50.60; H, 6.07. Found: C,
1
4
20
9
ose (8a and 8b).—A mixture of 7 (1.40 g,
50.30; H, 5.89%.
+
5
0
.73 mmol), Amberlite-120 resin (H form,
6-Deoxy-1,2-O-isopropylidene-i- -idofuran-
L
.5 g) and water (10 mL) was refluxed for 24
ose (9).—Compound 7 (0.60 g, 2.4 mmol)
was dissolved in 65% aq HOAc (5 mL), and
the mixture was stirred at 40 °C for 10 h.
After cooling to rt, the solution was co-evapo-
rated with EtOH and toluene at reduced pres-
sure, and the residue was purified by flash
chromatography (1:1 EtOAc–hexane) to af-
h. After cooling to rt, the resin was filtered
and washed with water. The filtrate was co-
evaporated with EtOH and toluene under re-
duced pressure to obtain a faint yellow oily
residue. This crude 6-deoxy- -idose was dis-
L
solved in pyridine (8 mL) and cooled to 0 C.
Acetic anhydride (4 mL) was slowly added to
the mixture, and the ice bath was removed.
After stirring at rt for 8 h, the solution was
cooled in an ice bath, MeOH (4 mL) was
slowly added, and the mixture was kept stir-
ring for 0.5 h. The resulting solution was
concentrated at reduced pressure, then diluted
with EtOAc (20 mL), and the whole mixture
was sequentially washed with 1 N HCl, satd
2
5
ford 9 (0.41 g, 81%): [h] −15.5° (c 1.0,
D
CHCl ): mp 89–90 °C; IR (CHCl ): 3441,
3
3
−
1
1
2985, 1458, 1376, 1217, 1070, 792 cm ; H
NMR (400 MHz, CDCl ): l 5.98 (d, J 3.6
3
1,2
Hz, 1 H, H-1), 4.52 (d, 1 H, H-2), 4.25 (dd,
J3,4 2.9, J3,OH 3.3 Hz, 1 H, H-3), 4.24–4.17
(ddq, J5,6 6.5, J5,OH 7.9 Hz, 1 H, H-5), 3.99 (t,
J4,5 2.9 Hz, 1 H, H-4), 3.98 (d, 1 H, OH-3),
2.35 (d, 1 H, OH-5), 1.49 (s, 3 H, Me), 1.37 (d,
1
3
NaHCO , and brine. The organic layer was
3 H, Me-6), 1.32 (s, 3 H, Me); C NMR (75
MHz, CDCl ): l 111.75 (C), 104.70 (CH),
3
dried over MgSO , filtered and concentrated
4
3
in vacuo. The residue was purified by flash
chromatography (1:2 EtOAc–hexane) to af-
ford 8a (0.63 g, 33%) and 8b (0.94g, 50%). 8a:
85.62 (CH), 82.07 (CH), 76.48 (CH), 67.07
(CH), 26.74 (CH ), 26.14 (CH ), 20.66 (CH );
3
3
3
+
HRFABMS: Calc. for C H O (MH )
9
17
5
2
5
[
h] −61.3° (c 1.0, CHCl ); IR (CHCl ):
205.1075; Found: m/z 205.1070.
D
3
3
−
1
1
2
989, 1751, 1438, 1372, 1223, 1053 cm ; H
5-O-tert-Butyldimethylsilyl-6-deoxy-1,2-O-
-idofuranose (10).—To a
NMR (400 MHz, CDCl ): l 6.00 (d, J 2.8
isopropylidene-i-
L
3
1,2
Hz, 1 H, H-1), 5.03 (t, J3,4 4.8 Hz, 1 H, H-3),
solution of 9 (0.19 g, 0.93 mmol) in DMF (1
mL) was consecutively added imidazole (0.18
g, 2.7 mmol) and tert-butylchlorodimethylsi-
lane (0.15 g, 1.0 mmol) at rt under nitrogen.
After 2 days, the mixture was diluted with
4
.88 (dd, J2,3 4.8 Hz, 1 H, H-2), 4.83 (dd, J4,5
.5 Hz, 1 H, H-4), 4.35 (dq, J5,6 6.6 Hz, 1 H,
2
H-5), 2.10 (s, 3 H, Ac), 2.07 (s, 3 H, Ac), 2.06
s, 3 H, Ac), 2.06 (s, 3 H, Ac), 1.19 (d, 3 H,
(