178
H.C. Hansen, G. Magnusson / Carbohydrate Research 322 (1999) 166–180
H, J=3.4, 10.1 Hz, H-3%), 3.86–3.96 (m, 2 H,
H-5, OCH2CH2Si), 3.68–3.75 (m, 2 H, H-
2%,5%), 3.49–3.61 (m, 1 H, OCH2CH2Si), 3.29
(t, 1 H, J=9.1 Hz, H-6%), 3.18 (dd, 1 H,
J=5.1, 8.7 Hz, H-6%), 0.78–0.95 (m, 2 H,
CH2Si), −0.10 (s, 9 H, SiCH3); 13C NMR
(CDCl3): l 166.8, 166.3, 166.1, 165.8, 165.7,
165.5, 128.1–138.6 (Ar), 101.5, 101.3, 100.7,
78.4, 76.9, 76.6, 75.9, 74.7, 74.2, 73.6, 73.4,
73.1, 72.8, 70.2, 68.2, 68.0, 67.9, 63.1, 62.6,
61.4, 18.3, −1.1; HRMS Anal. Calcd for
10.7 Hz, H-2%), 5.40 (dd, 1 H, J=7.9, 9.5 Hz,
H-2), 5.07 (dd, 1 H, J=2.6, 10.7 Hz, H-3%),
4.94 (d, 1 H, J=11.1 Hz, CH2Ph), 4.91 (d, 1
H, J=7.8 Hz, H-1%), 4.65–4.85 (m, 3 H), 4.71
(2 d, 1 H each, J=3.4 Hz and J=7.8 Hz,
H-1% and H-1), 4.49–4.60 (m, 5 H, incl. H-6%),
4.31 (d, 1 H, J=2.3 Hz, H-4%), 4.27 (t, 1 H,
J=9.5 Hz, H-4), 4.20 (br dd, 1 H, J=6.2,
11.2 Hz, H-6%), 4.05 (br dd, 1 H, J=6.2, 8.9
Hz, H-5%), 3.86–3.98 (m, 5 H, incl. H-2%,5, and
OCH2CH2Si), 3.73 (br t, 1 H, J=6.5 Hz,
H-5%), 3.53 (dt, 1 H, J=6.5, 10.1 Hz,
OCH2CH2Si), 3.08 (dd, 1 H, J=9.3, 11.6 Hz,
H-6%), 2.88 (dd, 1 H, J=5.5, 11.5 Hz, H-6%),
0.78–0.95 (m, 2 H, CH2Si), −0.11 (s, 9 H,
SiCH3); 13C NMR (CDCl3): l 166.8, 166.3,
166.1, 165.73, 165.66, 165.6, 127.8–139.2 (Ar),
101.5, 101.2, 100.7, 79.4, 76.9, 76.0, 75.8, 75.2,
74.84, 74.75, 73.8, 73.6, 73.5, 72.8, 70.2, 67.9,
63.1, 62.5, 49.9, 18.3, −1.1; HRMS Anal.
Calcd for C86H85O21N3SiNa [M+Na]:
1546.5343. Found: 1546.5347.
C86H85O21N3SiNa
Found: 1546.5348.
[M+Na]:
1546.5343.
2-(Trimethylsilyl)ethyl (2-azido-3,4,6-tri-O-
benzyl-2-deoxy-h- -galactopyranosyl)-(14)-
(2,3,6-tri-O-benzoyl-i- -galactopyranosyl)-
(14)-2,3,6-tri-O-benzoyl-i- -glucopyran-
oside (29).—A mixture of 4-methylphenyl 2-
azido-3,4,6-tri-O-benzyl-2-deoxy-1-thio-b-
D
D
D
D
-
galactopyranoside [2n] (28, 100 mg, 0.17
mmol), 19 (115 mg, 0.107 mmol), molecular
sieves (AW-300), and dry toluene (6 mL) was
cooled to −45 °C under N2. N-Iodosuccin-
imide (70 mg, 0.31 mmol) and tri-
fluoromethanesulfonic acid (0.007 mL, 0.08
mmol) were added, and the reaction mixture
was stirred for 2 h. Et3N (1 mL) and CH2Cl2
(10 mL) were added, and the mixture was
heated to rt, then filtered through Celite, and
washed with satd aq Na2S2O3 and water. The
organic phase was dried and concentrated,
and the residue was chromatographed (SiO2,
1:3 EtOAc–heptane) to give 29 (154 mg,
2-(Trimethylsilyl)ethyl (4-azido-2,3,6-tri-O-
benzyl-4-deoxy-h-
(2,3,6-tri-O-benzoyl-i-
(14)-2,3,6-tri-O-benzoyl-i-
D
-galactopyranosyl)-(14)-
-galactopyranosyl)-
-glucopyrano-
D
D
side (27).—To a solution of 8 (163 mg, 0.28
mmol) and 19 (150 mg, 0.14 mmol) in dry
toluene (8 mL) was added molecular sieves
(AW-300), and the mixture was cooled to
−45 °C under N2. N-Iodosuccinimide (95 mg,
0.42 mmol) and trifluoromethanesulfonic acid
(0.01 mL, 0.11 mmol) were added and the
reaction mixture was stirred for 3.5 h. Et3N (2
mL) and CH2Cl2 (20 mL) were added, the
mixture was filtered through Celite, and then
washed with satd aq Na2S2O3 and water. The
organic phase was dried and concentrated and
the residue was chromatographed (SiO2, 3:1
heptane–EtOAc) to give 27 (174 mg, 81%);
1
94%); [h]2D1 +68° (c 1.0, CHCl3); H NMR
(CDCl3): l 7.83–8.11 and 7.12–7.63 (45 H,
Ar–H), 5.83 (t, 1 H, J=9.4 Hz, H-3), 5.78
(dd, 1 H, J=7.9, 10.6 Hz, H-2%), 5.41 (dd, 1
H, J=7.8, 9.6 Hz, H-2), 5.09 (dd, 1 H, J=
2.5, 10.8 Hz, H-3%), 4.93 (d, 1 H, J=7.8 Hz,
H-1%), 4.81 (d, 1 H, J=3.4 Hz, H-1%), 4.73–
4.80 (m, 3 H, CH2Ph), 4.73 (d, 1 H, J=7.8
Hz, H-1), 4.67 (br d, 1 H, J=11.8 Hz, H-6),
4.56 (dd, 1 H, J=4.7, 11.9 Hz, H-6), 4.41 (d,
1 H, J=11.0 Hz, CH2Ph), 4.35 (d, 1 H,
J=2.6 Hz, H-4%), 4.13–4.33 (m, 4 H, H-
4,5%,6%), 3.85–4.08 (m, 7 H, incl. H-2%,5,
OCH2CH2Si), 3.77 (br t, 1 H, J=7.0 Hz,
H-5%), 3.54 (dt, 1 H, J=6.8, 10.2 Hz,
OCH2CH2Si), 3.30 (t, 1 H, J= 8.8 Hz, H-6%),
2.84 (dd, 1 H, J=5.1, 8.1 Hz, H-6%), 0.78–
0.95 (m, 2 H, CH2Si), −0.11 (s, 9 H, SiCH3);
1
[h]2D2 +48° (c 1.0, CHCl3); H NMR (CDCl3):
l 7.93–8.08, 7.80–7.84, 7.07–7.65 (45 H, Ar–
H), 5.82 (t, 1 H, J=9.3 Hz, H-3), 5.73 (dd, 1
H, J=7.9, 10.6 Hz, H-2%), 5.40 (dd, 1 H,
J=7.8, 9.5 Hz, H-2), 5.08 (dd, 1 H, J=2.7,
10.7 Hz, H-3%), 4.91 (d, 1 H, J=7.8 Hz, H-1%),
4.72 (d, J=7.9 Hz, H-1), 4.54 (d, J=3.5 Hz,
H-1%), 4.58–4.77 (m, 7 H) 4.41 (d, 1 H, J=
11.9 Hz, CH2Ph), 4.24–4.36 (m, 4 H, H-4,4%,
5%, and CH2Ph), 4.19–4.22 (m, 1 H, H-4%), 4.17
(dd, 1 H, J=6.2, 11.4 Hz, H-6%), 4.03 (dd, 1