K. K. Yeoh et al. / Carbohydrate Research 344 (2009) 586–591
589
sieves. ‘Petrol’ refers to the fraction of light petroleum ether boiling
in the range of 40–60 °C. Bovine milk b-1,4-galactosyltransferase
was purchased from Fluka at 1.05 U/mg (48279). Uridine diphos-
(s, CH2C„C), 96.3 (d, C-1), 175.0 (s, COCH3); HRMS (ESI+) Calcd
for C11H17N1Na1O6 (M+Na)+ 282.0948. Found 282.0947.
C11H17NO6 requires: C, 50.96; H, 6.61; N, 5.40. Found: C, 50.76,
H; 6.61; N, 5.32. Selected data for the undesired b anomer 7db
(Rf 0.3, DCM/MeOH, 4:1); dH (400 MHz, D2O) 1.98 (3H, s, CH3CO),
2.82 (1H, app. t, J 2.4, C„CH), 3.59–3.93 (5H, m, H-3, H-4, H-5,
H-6, H-60), 4.14 (1H, dd, J1,2 8.3, J2,3 10.6 Hz, H-2) 4.15–4.18 (2H,
m, CH2C„C), 4.80 (1H, d, J1,2 8.3 Hz, H-1); m/z (ESIꢁ) 258.1
(MꢁH)ꢁ 100%.
pho-D
-[U-14C]galactose was purchased from Amersham at
267 mCi/mmol. 14C-Radioactivity was measured with a Perkin–El-
mer Liquid Scintillation Counter.
Compounds 2a,11,15 2b,10,11 3,11,16 4,11,16 6a,12 6b,12 7a,17 and
7b18 were prepared as shown in Schemes 1 and 2, and exhibited
spectral data in agreement with those reported previously.
4.2. Prop-2-ynl 2-acetamido-2-deoxy-
a-
D-glucopyranoside (7c)
4.4. [10-(500-Deoxyuridin)-10H-10,20,30-triazol-40-yl] methyl-
a-D-
galactopyranoside (8a)
H2SO4-silica13 (600 mg) was added to a stirred suspension of
N-acetyl- -glucosamine 5c (2.21 g, 10.0 mmol) in propargyl alco-
D
Sodium ascorbate (50
lL of freshly prepared 1.0 M solution in
hol (8 mL, 69 mmol) at 65 °C. After 20 h, TLC (CH2Cl2/MeOH, 4:1)
indicated formation of two major products (Rf 0.2, 0.3), a minor
product (Rf 0.1) and complete consumption of starting material
(Rf 0.0). The reaction mixture was transferred to a short silica gel
column, and the excess propargyl alcohol was first removed by elu-
tion with DCM. Further elution (DCM/MeOH, 4:1) yielded the prod-
ucts, which were combined, concentrated in vacuo, and the
resulting residue was purified by flash chromatography (DCM/
MeOH, 4:1) to afford propargyl glycoside 7c (1.11 g, 43%) as an
water, 0.05 mmol) and copper(II) sulfate pentahydrate (50
l
L of
0.1 M solution in water, 0.005 mmol) were added to a stirred sus-
pension of propargyl glycoside 7a (109 mg, 0.5 mmol) and 50-azi-
do-50-deoxyuridine 4 (135 mg, 0.5 mmol) in a 1:1 mixture of
water and tert-butyl alcohol (3 mL). After 8 h, TLC (water/iPrOH/
ethyl acetate, 1:6:3) indicated formation of a major product (Rf
0.3) and complete consumption of starting materials (Rf 0.7, Rf
0.8). The reaction mixture was concentrated in vacuo, and the res-
idue was purified by flash chromatography (water/iPrOH/ethyl
acetate, 1:6:3) to afford triazole 8a (210 mg, 86%) as a pale yellow
anomeric mixture (
nol yielded the desired pure
a
:b ratio ꢀ1:1). Recrystallisation from metha-
a
-glycoside 7c (Rf 0.3, DCM/MeOH,
a
oil, ½a 2D5
ꢃ
+110 (c, 1.0 in MeOH); mmax (KBr disc) 3415 (br s, OH),
4:1, 0.49 g, 19% isolated yield) as a white crystalline solid; mp
16809 (s, C@O) cmꢁ1; dH (500 MHz, D2O) 3.59–3.64 (2H, m, H-6Gal
,
172–173 °C (MeOH); ½a D25
ꢃ
+155 (c, 1.0 in MeOH); mmax (KBr disc)
H-6Gal), 3.73–3.77 (2H, m, H-2Gal, H-4Gal), 3.81–3.85 (1H, m, H-
5Gal), 3.89 (1H, br s, H-3Gal), 4.10 (1H, app. t, J 6 Hz, H-3uridine),
4.25 (1H, dd, J1,2 3.5 Hz, J2,3 6 Hz, H-2uridine), 4.30–4.33 (1H, m, H-
4uridine), 4.65 (1H, d, J 12.6 Hz, OCHH), 4.71–4.76 (2H0, m, OCHH,
3445 (s, N–H), 3285 (s, OH), 1634 (s, C@O) cmꢁ1; dH (500 MHz,
D2O) 2.01 (3H, s, COCH3), 2.86 (1H, app. t, J 2.3 Hz, C„CH), 3.47
(1H, app. t, J 9.5 Hz, H-4), 3.69–3.72 (2H, m, H-3, H-5), 3.76 (1H,
0
0
0
0
0
0
dd, J5,6 5.0 Hz, J6,6 12.3, H-6), 3.83 (1H, dd, J5,6 2.2 Hz, J6,6
H-5uridine), 4.82 (1H, dd, J4,5 3.5 Hz, J5,5 14.8 Hz, H-5uridine), 4.98
(1H, br s, H-1Gal), 5.70 (1H, d, J1,2 3.5 Hz, H-1uridine), 5.78 (1H, d, J
8.1 Hz, CH@CHN), 7.31 (1H, d, J 8.1 Hz, CH@CHN), 8.01 (1H, s, tria-
zole); dC (125 MHz, D2O) 50.7 (d, C-5uridine), 60.1 (t, OCH2), 61.0
(t, C-6Gal), 68.1, 69.1, 69.4 (3 ꢄ d, C-2Gal, C-3Gal, C-4Gal), 69.9 (d,
C-3uridine), 71.1 (d, C-5Gal), 72.5 (d, C-2uridine), 80.7 (d, C-4uridine),
91.4 (d, C-1uridine), 98.1 (d, C-1Gal), 102.2 (d, CH@CHN), 126.3 (d, tri-
azole C-5), 142.5 (d, CH@CHN), 144.0 (s, triazole C-4), 151.2, 166.1
(2 ꢄ s, C@O); HRMS (ESI+) Calcd for C18H25N5Na1O11 (M+Na)+
510.1443. Found 510.1445. C18H25N5O11 requires: C, 44.35; H,
5.17; N, 14.37. Found: C, 44.22; H, 5.32; N, 14.32. m/z (ESIꢁ)
486.1 (MꢁH)ꢁ 100%.
12.3 Hz, H-60), 3.92 (1H, dd, J1,2 3.8 Hz, J2,3 10.7 Hz, H-2), 4.24
(1H, dd, J 2.3 Hz, Jgem 16.1 Hz, CHHC„C), 4.31 (1H, dd, J 2.3 Hz, Jgem
16.1 Hz, CHHC„CH), 5.02 (1H, d, J1,2 3.8 Hz, H-1); dC (125 MHz,
D2O) 21.8 (s, CH3CO), 53.4 (d, C-2), 55.1 (t, OCH2), 60.3 (t, C-6),
69.8 (d, C-4), 70.9, 72.3 (2 ꢄ d, C-3, C-5), 75.8 (d, CH2C„C) 79.0
(s, CH2C„C), 95.9 (d, C-1), 174.5 (s, COCH3); m/z (ESIꢁ) 258.1
(MꢁH)ꢁ 100%). (Found: C, 50.88, H; 6.63; N, 5.41. C11H17NO6
requires: C, 50.96; H, 6.61; N, 5.40%).
4.3. Prop-2-ynl 2-acetamido-2-deoxy-a-D-galactopyranoside
(7d)
H2SO4-silica13 (600 mg) was added to a stirred suspension of N-
acetyl- -galactosamine 5d (2.21 g, 10.0 mmol) in propargyl alcohol
4.5. [10-(500-Deoxyuridin)-10H-10,20,30-triazol-40-yl] methyl-
a-D-
glucopyranoside (8b)
D
(2.9 mL, 50.0 mmol) at 65 °C. After 3.5 h, TLC (DCM/MeOH, 4:1)
indicated the formation of a major product (Rf 0.4), two minor
products (Rf 0.3, 0.2), and the complete consumption of starting
material (Rf 0.0). The reaction mixture was transferred to a short
silica gel column, and the excess propargyl alcohol was first re-
moved by elution with DCM. Further elution (DCM/MeOH, 4:1)
yielded the products, which were combined, concentrated in va-
cuo, and the resulting residue was then purified by flash chroma-
tography (DCM/MeOH, 4:1) to afford propargyl glycoside 7d
Sodium ascorbate (100
water, 0.10 mmol) and copper(II) sulfate pentahydrate (100
l
L of freshly prepared 1.0 M solution in
lL of
0.1 M solution in water, 0.01 mmol) were added to a stirred sus-
pension of propargyl glycoside 7b (109 mg, 0.5 mmol) and 50-azi-
do-50-deoxyuridine 4 (135 mg, 0.5 mmol) in a 1:1 mixture of
water and tert-butyl alcohol (3 mL) at rt. After 24 h, TLC (water/
iPrOH/ethyl acetate, 1:6:3) indicated formation of a major product
(Rf 0.3) and complete consumption of starting materials (Rf 0.8, Rf
0.9). The reaction mixture was concentrated in vacuo, and the res-
idue was purified by flash chromatography (water/iPrOH/ethyl
acetate, 1:6:3) to afford triazole 8b (160 mg, 66%) as a colourless
(1.41 g, 54%), as an anomeric mixture (
sation from methanol furnished the desired pure
a
:b ratio ꢀ3:2). Recrystalli-
a
-glycoside 7d
a
(Rf 0.4, DCM/MeOH, 4:1, 0.81 g, 31% isolated yield) as a colourless
crystalline solid; mp 224–226 °C (MeOH); ½a D25
ꢃ
+233 (c, 1.0 in
oil, ½a 2D5
ꢃ
+108 (c, 1.0 in MeOH); mmax (KBr disc) 3419 (br s, OH),
MeOH); mmax (KBr disc) 3509 (s, NH), 3289 (s, OH), 1651 (s, C@O)
cmꢁ1; dH (400 MHz, D2O) 1.96 (3H, s, COCH3), 2.85 (1H, t, J
2.2 Hz, C„CH), 3.69–3.74 (2H, m, H-6, H-60), 3.87 (1H, dd, J2,3
11.1 Hz, J3,4 3.0 Hz, H-3), 3.93–3.97 (2H, m, H-4, H-5), 4.15 (1H,
dd, J1,2 3.8 Hz, J2,3 10.9 Hz, H-2), 4.24, 4.29 (2H, ABq, J 16.1 Hz,
OCH2), 5.04 (1H, d, J1,2 3.8 Hz, H-1); dC (100 MHz, D2O) 21.9 (s,
COCH3), 48.9 (d, C-2), 55.0 (t, OCH2), 61.4 (t, C-6), 67.9 (d, C-3),
68.7 (d, C-4 or C-5), 71.7 (d, C-4 or C-5), 75.8 (d, CH2C„C) 79.0
1691 (s, C@O) cm-1; dH (500 MHz, D2O) 3.37 (1H, app. t, J 9.5 Hz,
H-4Glc), 3.52 (1H, dd, J1,2 3.8 Hz, J2,3 9.8 Hz, H-2Glc), 3.55–3.58
(1H, m, H-5Glc), 3.62–3.70 (3H, m, H-3Glc, H-6Glc, H-60Glc), 4.13
(1H, app. t, J 6 Hz, H-3uridine), 4.29 (1H, dd, J1,2 3.6 Hz, J2,3 6 Hz,
H-2uridine) 4.33–4.37 (1H, m, H-4uridine), 4.65–4.73 (3H, m, OCH2,
0
0
0
H-5uridine), 4.86 (1H, dd, J4,5 3.3 Hz, J5,5 15.0 Hz, H-5uridine), 4.98
(1H, d, J1,2 3.8 Hz, H-1Glc), 5.72 (1H, d, J1,2 3.6 Hz, H-10uridine), 5.80
(1H, d, J 8.2 Hz, CH@CHN), 7.32 (1H, d, J 8.2 Hz, CH@CHN), 8.08