K. Clinch et al. / Carbohydrate Research 337 (2002) 1095–1111
1105
through a plug of Biogel P-2 resin (water) gave sulfate
salt 4 as a colourless solid (111 mg, 78%); [h]2D1 −37° (c
0.62, water); TLC (11.7:5:1 CH2Cl2–MeOH–water): Rf
0.28; IR (CHBr3 mull): w 3659–3159 (br, s), 1653 (s),
cooled to −30 °C and BF3·OEt2 (0.135 mL, 1.10
mmol) was added dropwise over 10 min. After 1.5 h
Et3N (1.0 mL) was added and the mixture warmed to
ambient temperature and the volatiles were evaporated.
Chromatography (7:3 toluene–acetone) gave a mono-
hydroxy product (556 mg) (Rf 0.22) which was dis-
solved in pyridine (10 mL) and Ac2O (5 mL) and left at
ambient temperature for 48 h. The volatiles were evap-
orated and the residue was dissolved in EtOAc, washed
with aq HCl (10%), aq satd NaHCO3, dried and the
volatiles again evaporated. Chromatography (7:3
EtOAc–hexanes) gave 18 as a colourless foam (560 mg,
53%); [h]2D1 −31° (c 1.32, CHCl3); TLC (4:1 EtOAc–
1
1590 (s), 1515 (s), 1344 (s), 1248 (s), 1072 (s) cm−1; H
NMR (D2O): l 8.25 (d, 2 H, J 9.2 Hz, ArH), 7.21 (d,
2 H, J 9.2 Hz, Ar), 5.36 (d, 1 H, J1,2 8.4 Hz, H-1), 4.57
(d, 1 H, J1%,2% 7.7 Hz, H-1%), 4.49 (d, 1 H, J6a,6b 11.0 Hz,
H-6a), 4.35 (dd, 1 H, J5,6b 4.8 Hz, H-6b), 4.16–4.04 (m,
2 H, H-5, H-2), 3.95 (d, 1 H, J3%,4%, 3.3 Hz, H-4%),
3.92–3.84 (m, 2 H, H-4, H-3), 3.83–3.72 (m, 3 H,
H-6a%, H-6b%, H-5%), 3.70 (dd, 1 H, J2%,3% 10.0 Hz, H-3%),
3.53 (dd, 1 H, H-2%), 2.03 (s, 3 H, Ac); 13C NMR (D2O):
l 176.1 (s), 162.8 (s), 143.8 (s), 127.3 (d), 117.7 (d),
103.9 (d, C-1%), 99.7 (d, C-1), 78.6 (d, C-4), 76.6 (d,
C-5%), 74.2 (d, C-5), 73.7 (d, C-3%), 73.2 (d, C-3), 72.2 (d,
C-2%), 69.9 (d, C-4%), 67.5 (t, C-6), 62.3 (t, C-6%), 56.1
(d, C-2), 23.4 (q, Me). FABMS: m/z Calcd. for
1
hexanes): Rf 0.52; H NMR (CDCl3): l 8.14 (d, 2 H, J
9.1 Hz, ArH), 7.64–7.57 (m, 4 H, ArH), 7.45–7.26 (m,
4 H, ArH), 7.12 (t, 2 H, J 7.6 Hz, ArH), 7.03 (d, 2 H,
J 9.1 Hz, ArH), 5.98 (d, 1 H, JNH,2 9.1 Hz, exchanged
with D2O, NH), 5.37 (d, 1 H, J3%,4% 3.3 Hz, H-4%),
5.22–5.15 (m 2 H, H-3, H-1), 5.11 (dd, 1 H, J2%,3% 10.5,
J1%,2% 7.9 Hz, H-2%), 4.99 (dd, 1 H, H-3%), 4.73 (d, 1 H,
H-1%), 4.39 (q, 1 H, after D2O exchange became a dd,
J2,3 8.7, J1,2 6.9 Hz, H-2), 4.21 (t, 1 H, J4,5=J3,4 7.7 Hz,
H-4), 4.14 (d, 2 H, J 6.6 Hz, H-6a%, H-6b%), 3.99 (dd, 1
H, J6a,6b 11.3, J5,6a 3.6 Hz, H-6a), 3.85–3.73 (m, 2 H,
H-5%, H-6b), 3.65–3.54 (m, 1 H, H-5), 2.11, 2.07, 2.06,
1.84 (4s, 12 H, 4 Ac), 2.02 (s, 6 H, 2 Ac), 1.05 (s, 9 H,
Si-But); 13C NMR (CDCl3): l 171.0 (s), 170.3 (s), 169.9
(s), 169.1 (s), 161.6 (s), 142.7 (s), 135.7 (d), 135.3 (d),
133.0 (s), 131.8 (s), 130.1 (d), 129.9 (d), 127.9 (d), 127.6
(d), 125.6 (d), 116.5 (d), 100.2 (d, C-1%), 98.0 (d, C-1),
75.5 (d, C-5), 73.2 (d, C-4), 71.7 (d, C-3), 70.9 (d, C-5%),
70.8 (d, C-3%), 69.4 (d, C-2%) 66.8 (d, C-4%), 61.3 (t, C-6),
61.1 (t, C-6%), 52.3 (d, C-2), 26.8 (q), 23.2 (q), 20.9 (q),
20.6 (q), 20.5 (q), 20.3 (q), 19.2 (s, Si-But). FABMS:
m/z Calcd. for C46H57N2O18Si [M+H]+: 953.3376.
Found: 953.3362.
C20H28N2NaO16S
607.1040.
[M+H]+:
607.1057.
Found:
4-Nitrophenyl 2-acetamido-6-O-tert-butyldiphenylsi-
lyl-2-deoxy-i- -glucopyranoside (17).—tert-Butyl-
chlorodiphenylsilane (1.96 mL, 7.53 mmol) was added
-glucopyra-
D
to 4-nitrophenyl 2-acetamido-2-deoxy-b-
D
noside34 (2.00 g, 5.8 mmol) in pyridine (30 mL) and the
solution was stirred at ambient temperature for 16 h.
The solvent was evaporated and the residue dissolved in
EtOAc then washed with aq HCl (10%), aq satd
NaHCO3, dried and the solvent evaporated. Chro-
matography (19:1 CH2Cl2–MeOH) gave the silyl ether
17 as a colourless foam (3.21 g, 95%); [h]2D0 −69° (c
1
1.01, CHCl3); TLC (9:1 CH2Cl2–MeOH): Rf 0.43; H
NMR (CDCl3): l 8.07 (d, 2 H, J 9.2 Hz, ArH), 7.62 (d,
4 H, J 6.7 Hz, ArH), 7.42–7.25 (m, 6 H, ArH), 7.07 (d,
2 H, J 9.2 Hz, ArH), 5.86 (br.d, 1 H, JNH,2 6.0 Hz,
exchanged with D2O, NH), 5.30 (d, 1 H, J1,2 8.1 Hz,
H-1), 4.29 (d, 1 H, J 3.1 Hz, exchanged with D2O, OH),
4.03 (dd, 1 H, J6a,6b 11.0, J5,6a 2.8 Hz, H-6a), 3.96–3.82
(m, 2 H, H-6b, H-3), 3.81–3.71 (m, 1 H, after D2O
exchange became a dd, J2,3 10.1 Hz, H-2), 3.70–3.55
(m, 2 H, H-5, H-4), 2.97 (s, 1 H, exchanged with D2O,
OH), 2.07 (s, 3 H, Ac), 1.05 (s, 9 H, Si-But); 13C NMR
(CDCl3): l 172.6 (s), 161.7 (s), 142.6 (s), 135.6 (d), 135.5
(d), 133.0 (s), 132.8 (s), 129.8 (d), 127.7 (d), 125.7 (d),
116.4 (d), 97.9 (d), 76.7 (d), 75.1 (d), 71.5 (d), 63.8 (t),
56.8 (d), 26.8 (q), 23.5 (q), 19.2 (s). FABMS: m/z Calcd.
for C30H37N2O8Si [M+H]+: 581.2319. Found:
581.2320.
4-Nitrophenyl
silyl-2-deoxy-4,6-O-(4-methoxybenzylidene)-i-
2-acetamido-3-O-tert-butyldimethyl-
-gluco-
D
pyranoside (19).—Imidazole (2.19 g, 32.2 mmol) and
TBDMSCl (2.42 g, 16.1 mmol) were added to a solu-
tion of 4-nitrophenyl 2-acetamido-2-deoxy-4,6-O-(4-
methoxybenzylidene)-b-D
-glucopyranoside35 (4.90 g,
10.7 mmol) in dry DMF (10 mL) and the mixture was
left at ambient temperature for 16 h then heated at
40 °C for 3 h. The solvent was evaporated and the
residue dissolved in EtOAc. The solution was washed
with water, dried and the solvent evaporated. Chro-
matography (3:74:6 EtOAc–hexanes) gave silyl ether
19 as a colourless foam (3.1 g, 61%); mp (EtOAc–hex-
anes, needles) 138–140 °C; [h]2D1 −25° (c 0.79, CHCl3);
4-Nitrophenyl (2,3,4,6-tetra-O-acetyl-i-
ranosyl)-(14)-2-acetamido-3-O-acetyl-6-O-tert-butyl-
diphenylsilyl-2-deoxy-i- -glucopyranoside (18).—Pow-
D-galactopy-
1
D
TLC (2:3 EtOAc–hexanes): Rf 0.56; H NMR (CDCl3):
,
dered 4 A molecular sieve (3.0 g) was added to a
l 8.19 (d, 2 H, J 9.2 Hz, ArH), 7.40 (d, 2 H, J 8.7 Hz,
ArH), 7.06 (d, 2 H, J 9.2 Hz, ArH), 6.89 (d, 2 H, J 8.8
Hz, ArH), 5.83 (d, 1 H, J1,2 8.3 Hz, H-1), 5.78 (d, 1 H,
JNH,2 8.6 Hz, exchanged with D2O, NH), 5.47 (s, 1 H,
CHAr), 4.48 (t, 1 H, J3,4=J2,3 9.2 Hz, H-3), 4.42–4.23
solution of diol 17 (636 mg, 1.10 mmol) and tetra-O-
acetyl-a-
D
-galactopyranosyl
(812 mg, 1.65 mmol) in dry CH2Cl2 (30 mL). The
mixture was stirred at ambient temperature for 2 h,
trichloroacetimidate25,26