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WIRSCHING ET AL.
1
CHCl3). IR: n 3187 (NH), 1671 (C¼O) cmÀ 1. H NMR (CDCl3): d 0.06 [s,
9H, Si(CH3)3], 3.32 (s, 3H, OCH3), 3.54 (dd, 1H, H-50a), 3.95 (dd, 1H, H-20),
4.31 (ddd, 1H, H-40), 4.44 (dd, 1H, H-50b), 4.46 (dd, 1H, H-30), 4.75 (s, 2H,
CH2C6H4F), 4.87 (d, 1H, H-10), 7.03 (ddd, 1H, Har-3), 7.11 (ddd, 1H, Har-
5), 7.25–7.29 (m, 1H, Har-4), 7.45 (ddd, 1H, Har-6), 7.56 (s, 1H, H-6), 8.76
0
0
0
0
0
0
0
0
0
0
(bs, 1H, NH). J1 ,2 ¼ 4.1, J2 ,3 ¼ 5.7, J3 ,4 ¼ 6.5, J4 ,5 a ¼ 8.3, J4 ,5 b ¼ 3.5,
0
0
J5 a,5 b ¼ 14.5, J3ar,4ar ¼ 8.5, J3ar,5ar ¼ 1.2, J3ar,F ¼ 9.9, J4ar,5ar ¼ 7.5, J4ar,6ar
¼
1.8, J5ar,6ar ¼ 7.5, J6ar,F ¼ 7.5. 13C NMR (CDCl3): d; À 0.1 [Si(CH3)3], 49.6
(C-50), 55.6 (OCH3), 66.2 (d, CH2C6H4F), 74.6 (C-30), 75.3 (C-40), 84.7 (C-
20), 101.0 (C-10), 108.6 (C-5), 115.2 (d, Car-3), 124.2 (d, Car-5), 124.6 (d,
Car-1), 129.9 (d, Car-4), 130.5 (d, Car-6), 142.6 (C-6), 150.6 (2-CO), 159.5
(4-CO), 160.6 (d, Car-2). J1ar,F ¼ 14.6, J2ar,F ¼ 247.2, J3ar,F ¼ 21.4,
J4ar,F ¼ 8.3, J5ar,F ¼ 3.6, J6ar,F ¼ 4.2, JCH2,F ¼ 3.6.
Methyl 5-N-(5-Bromouracil-1-yl)-5-deoxy-2-O-(2-fluorobenzyl)-3-O-tri-
methylsilyl-a-D-xylofuranoside (7). 211 mg (73%), from
2
(142 mg,
0.56 mmol) and 5-bromo-2,4-bis-O-trimethylsilyluracil13 (792 mg, 2.07 mmol).
20
M.p. 129ꢀC (PE=EA 1:3, Rf ¼ 0.54). ½aꢂD ¼ þ109:0 (c ¼ 1.0 in CHCl3). IR: n;
1
3208 (NH), 1695 (C¼O) cmÀ 1. H NMR (CDCl3): d 0.01 [s, 9H, Si(CH3)3],
3.32 (s, 3H, OCH3), 3.60 (dd, 1H, H-50a), 3.94 (dd, 1H, H-20), 4.22 (ddd, 1H,
H-40), 4.35 (dd, 1H, H-50b), 4.54 (dd, 1H, H-30), 4.77 (s, 2H, CH2C6H4F), 4.89
(d, 1H, H-10), 7.02 (ddd, 1H, Har-3), 7.12 (ddd, 1H, Har-5), 7.26–7.29 (m, 1H,
Har-4), 7.46 (ddd, 1H, Har-6), 7.65 (s, 1H, H-6), 9.66 (bs, 1H, NH).
0
0
0
0
0
0
0
0
0
0
J1 ,2 ¼ 4.2, J2 ,3 ¼ 6.0, J3 ,4 ¼ 6.0, J4 ,5 a ¼ 9.2, J5 a,5 b ¼ 14.3, J3ar,4ar ¼ 8.3,
J3ar,5ar ¼ 1.1, J3ar,F ¼ 9.9, J4ar,5ar ¼ 7.5, J4ar,6ar ¼ 1.8, J5ar,6ar ¼ 7.5, J6ar,F ¼ 7.5.
13C NMR (CDCl3): d À 0.1 [Si(CH3)3], 48.1 (C-50), 55.8 (OCH3), 66.3 (d,
CH2C6H4F), 74.3 (C-30), 74.9 (C-40), 84.8 (C-20), 96.3 (C-5), 101.0 (C-10),
115.3 (d, Car-3), 124.2 (d, Car-5), 124.5 (d, Car-1), 129.9 (d, Car-4), 130.5 (d,
Car-6), 145.2 (C-6), 150.7 (2-CO), 160.8 (d, Car-2), 164.1 (4-CO).
J1ar,F ¼ 14.5, J2ar,F ¼ 247.4, J3ar,F ¼ 21.4, J4ar,F ¼ 8.1, J5ar,F ¼ 3.6, J6ar,F ¼ 4.2,
JCH2,F ¼ 3.7.
Methyl 5-Deoxy-2-O-(2-fluorobenzyl)-5-N-(5-iodouracil-1-yl)-3-O-trimethyl-
silyl-a-D-xylofuranoside (8). 269 mg (76%), from 2 (160 mg, 0.63 mmol)
and 5-iodo-2,4-bis-O-trimethylsilyluracil13 (920 mg, 2.41 mmol). M.p. 156–
20
158ꢀC (PE/EA 1:3, Rf ¼ 0.50, decomp.). ½aꢂD ¼ þ90:0 (c ¼ 1.0 in CHCl3).
1
IR: n 3205 (NH), 1679 (C¼O) cmÀ 1. H NMR (CDCl3): d 0.10 [s, 9H,
Si(CH3)3], 3.37 (s, 3H, OCH3), 3.61 (dd, 1H, H-50a), 3.84 (dd, 1H, H-20),
4.14–4.21 (m, 2H, H-40, H-50b), 4.40 (dd, 1H, H-30), 4.66 (s, 2H,
CH2C6H4F), 4.90 (d, 1H, H-10), 7.03 (ddd, 1H, Har-3), 7.11 (ddd, 1H, Har-
5), 7.25–7.29 (m, 1H, Har-4), 7.45 (ddd, 1H, Har-6), 7.73 (s, 1H, H-6), 8.75
0
0
0
0
0
0
0
0
0
0
(bs, 1H, NH). J1 2 ¼ 4.1, J2 ,3 ¼ 5.7, J3 4 ¼ 6.0, J4 ,5 a ¼ 9.2, J5 a,5 b ¼ 14.6,
J3ar,4ar ¼ 8.5, J3ar,5ar ¼ 1.1, J3ar,F ¼ 9.9, J4ar,5ar ¼ 7.5, J4ar,6ar ¼ 1.8, J5ar,6ar
¼
13
7.5, J6ar,F ¼ 7.5. C NMR (CDCl3): d À 0.1 [Si(CH3)3], 48.3 (C-50), 55.6