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J. Xia et al. / Carbohydrate Research 328 (2000) 147–163
glucopyranoside (10).—A solution of donor 9
(1.109 g, 1.90 mmol), disaccharide acceptor 8
(500 mg, 0.76 mmol), NIS (1.28 g, 5.7 mmol)
in dry 3:1 CH2Cl2–MeCN (30 mL) containing
3A-MS (5 g) was cooled (−45 to −40 °C)
and stirred in an atmosphere of N2 for 1.5–2
h. TfOH (0.15 mL) was then added dropwise
and the stirring was continued at the same
temperature for 1.5 h. More TfOH (40 mL)
was then added, and stirring was continued
for an additional 1 h. The solution was neu-
tralized with satd aq NaHCO3 soln, the solids
were filtered off, and the organic layer was
washed with satd NaHCO3 soln, 10% Na2S2O3
and water, dried (Na2SO4) and concentrated.
The crude mixture was placed on a short silica
gel column and eluted with 1:5 hexane–
EtOAc to give pure compound 10 (430 mg,
0.380 mmol, 45%) as a glass white solid: TLC
Rf =0.35 (1:5 hexane–EtOAc); 1H NMR
(CDCl3, 400 MHz) l 8.00–7.90 (m, 2 H,
ArH), 7.90–7.80 (m, 2 H, ArH), 7.60–7.40
(m, 2 H, ArH), 7.40–7.20 (m, 3 H, ArH),
5.46–5.43 (m, 1 H, H-8¦), 5.37 (s, 1 H, benzyl-
idene proton), 5.32–5.27 (t, 2 H, H-7¦,
NHAc¦), 5.21–5.19 (d, 1 H, J1,2 8.8 Hz, H-1),
5.00–4.90 (ddd, 1 H, H-4¦), 4.85–4.82 (d, 1 H,
J 2.8 Hz, H-4%), 4.57–4.55 (d, 1 H, J1%,2% 8.0
Hz, H-1%), 4.48–4.44 (dd, 1 H, J 8.8, 10.8 Hz,
H-3), 4.41–4.38 (dd, 1 H, J 2.2, Jgem 12.6 Hz,
H-9b¦), 4.27–4.19 (m, 3 H, H-3%, H-6a, H-2),
4.16–4.04 (m, 4 H, H-6¦, H-6b%, H-9a¦, H-6b),
3.98–3.83 (m, 4 H, H-5¦, H-2%, H-5%, H-5),
3.68 (s, 3 H, COOCH3), 3.58–3.56 (m, 2 H,
H-6a%, H-4), 3.46 (s, 3 H, OCH3), 2.77–2.72
(dd, 1 H, J3e¦,4¦ 4.4, Jgem 12.6 Hz, H-3e¦), 2.13
(s, 3 H, Ac), 2.11 (s, 3 H, Ac), 2.02 (s, 3 H,
Ac), 2.00 (s, 3 H, Ac), 1.98 (s, 3 H, Ac), 1.97
(t, 1 H, J3a¦,3e¦ 12.6 Hz, H-3a¦), 1.25 (s, 9 H,
t-Bu); 13C NMR (CDCl3, 100.6 MHz) l
178.25, 171.07, 170.82, 170.46, 170.42, 170.33,
137.90, 134.12, 132.14, 129.19, 128.33, 126.58,
123.48, 104.49, 101.11, 99.24, 97.45 (C-1, C-1%,
C-2¦, benzylidene carbon), 83.27, 75.05, 73.99,
73.38, 72.86, 70.14, 68.94, 68.65, 68.59, 68.50,
67.30, 66.79, 63.54, 62.85, 56.80, 56.11, 53.20,
50.05, 38.56 (C-3¦), 27.43 (3 CH3) (Ac), 23.40
(Ac), 21.47 (Ac), 21.00 (Ac), 20.93 (Ac); Anal.
Calcd for C53H66N2O25: C, 56.28; H, 5.89; N,
2.48. Found: C, 55.95; H, 5.95; N, 2.40.
7.2 Hz, H-1%), 4.04–3.98 (dd, 1 H), 3.79–3.60
(m, 5 H), 3.60–3.50 (m, 2 H), 3.50–3.40 (dd,
1 H), 3.36 (s, 3 H, OCH3), 1.25 (s, 9 H, t-Bu);
13C NMR (CD2Cl2, 100.6 MHz) l 180.14,
136.07, 133.39, 124.72, 105.71, 100.96 (C-1,
C-1%), 81.86, 77.85, 75.26, 74.93, 72.95, 71.52,
70.79, 64.41, 63.12, 58.08, 57.46, 40.4
[C(CH3)3], 27.95 (CH3); Anal. Calcd for
C26H35NO13: C, 54.83; H, 6.21; N, 2.46.
Found: C, 54.93; H, 6.21; N, 2.32.
Methyl (4,6-O-benzylidene-i-
ranosyl)-(14)-2-deoxy-6-O-trimethylacetyl-
2-phthalimido-i- -glucopyranoside (8).—To a
D
-galactopy-
D
solution of compound 7 (830 mg, 1.46 mmol),
a,a-dimethoxytoluene (0.5 mL, 2.3 mmol) in
dry MeCN (20 mL), was added p-TsOH·H2O
(191 mg). The mixture was stirred overnight at
rt. The acid was then neutralized with Et3N,
and the solution concentrated. The crude
product was applied to a short column of
silica gel eluted with 20:1 CH2Cl2–MeOH to
give pure compound 8 (752 mg, 78%) as an
amorphous solid: TLC Rf=0.44 (20:1
CH2Cl2 –CH3OH) [h]D +31.7° (c 1.0, CHCl3);
1H NMR (CD2Cl2, 400 MHz): l 7.90–7.80
(m, 2 H, ArH), 7.80–7.70 (m, 2 H, ArH),
7.50–7.40 (m, 2 H, ArH), 7.40–7.30 (m, 3 H,
ArH), 5.52 (s, 1 H, benzylidene proton), 5.15–
5.13 (d, 1 H, J1,2 8.4 Hz, H-1), 4.66–4.63 (dd,
1 H, J 1.6, Jgem 11.6 Hz, H-6a), 4.50–4.40 (dd,
1 H, H-3), 4.38–4.36 (d, 1 H, J1%,2% 8.2 Hz,
H-1%), 4.30–4.20 (dd, 1 H, J 5.6, Jgem 12.0 Hz,
H-6b), 4.20–4.10 (m, 2 H, H-4%, H-6a%), 4.10–
4.00 (m, 2 H, H-2, H-6b%), 3.80–3.70 (m, 2 H,
H-5, H-2%), 3.70–3.60 (m, 1 H, H-3%), 3.56 (m,
1 H, H-5%), 3.53–3.49 (t, 1 H, H-4), 3.41 (s, 3
H, OCH3), 3.30 (d, 1 H, J2%,OH% 2.8 Hz, OH-2%),
2.70 (d, 1 H, J3%,OH% 8.0 Hz, OH-3%), 1.24 (s, 9
H, t-Bu); 13C NMR (CD2Cl2, 100.6 MHz): l
138.05, 134.47, 132.17, 129.50, 128.55, 126.61,
123.58, 104.48, 101.50, 99.50 (C-1, C-1%, ben-
zylidene carbon), 83.12, 75.36, 73.67, 72.99,
71.81, 70.11, 69.14, 67.50, 63.55, 57.00, 56.20,
39.80 [C(CH3)3], 27.36 (3 CH3); Anal. Calcd
for C33H39NO13: C, 60.27; H, 5.99; N, 2.13.
Found: C, 60.02; H, 6.15; N, 1.89.
Methyl [methyl (5-acetamido-4,7,8,9-tetra-
O-acetyl-3,5-dideoxy-
D
-glycero-h- -galacto-
D
non - 2 - ulopyranosyl)onate] - (23) - (4,6-O-
benzylidene-i- -galactopyranosyl)-(14)-2-
deoxy-2-phthalimido-6-O-trimethylacetyl-i-
D
Methyl [methyl (5-acetamido-4,7,8,9-tetra-
D
-
O-acetyl-3,5-dideoxy-
D
-glycero-h- -galacto-
D