2952
Helvetica Chimica Acta Vol. 86(2003)
combined org. phase was washed with sat. NaHCO3 soln. (3 Â 50 ml) and brine (3 Â 50 ml), dried (Na2SO4),
and evaporated and the remaining yellow foam chromatographed (silica gel, Et2O/AcOEt 1:0, 4 :1, 1:1, 0 :1):
14a (605 mg, 35%), 15a (746mg, 43%), and starting 12 (132 mg, 9%) as colorless foams. The products of the two
1
methods were identical according to TLC and H-NMR.
Data of 14a: UV (MeCN): 252 (15500), 309 (6800). 1H-NMR (CDCl3, 300 MHz): 1.06( s, t-Bu); 1.76 1.88
(m, 1 HÀC(5')); 1.97 2.12 (m, 1 HÀC(5'), HÀC(3')); 2.14 2.22 (m, 1 HÀC(2')); 2.51 (s, Me (to)); 2.51 2.63
(m, 1 HÀC(2')); 3.69 (d, J 5.0, CH2ÀC(3')); 3.74 3.85 (−dt×, J 2.0, 6.0, 2 HÀC(6')); 4.15 (dt, J 3.5, 9.0,
HÀC(4')); 6.07 (dd, J 2.5, 7.0, HÀC(1')); 7.28 (m, HÀC(3)(to), HÀC(5)(to)); 7.34 7.48 (m, 6H, Ph 2Si);
7.48 7.58 (m, HÀC(4)(to), HÀC(6)(to), HÀC( 5 )) ; 7.62 7.64 ( m, 4 H, Ph2Si); 8.04 (d, J 7.4, HÀC(6)); 8.32
(br., NH). 13C-NMR (CDCl3, 75 MHz): 19.23 (s, Me3C); 20.10 (q, Me (to)); 26.07 (q, Me3C); 36.15 (t, C(5'));
37.13 (t, C(2')); 44.51 (d, C(3')); 60.89 (t, C(6')); 62.90 (t, CH2ÀC(3')); 83.19 (d, C(4')); 87.89 (d, C(1')); 95.91
(d, C(5)); 126.16, 126.98 (2d, to); 127.87, 129.96(2 d, Ph2Si); 131.58, 131.81 (2d, to); 132.82 (s, Ph2Si); 134.11
(s, Cipso (to)); 135.55 (d, Ph2Si); 137.47 (s, Co (to)); 144.00 (d, C(6)); 162.11 (s, CO). FAB-MS (NOBA; pos.):
634 (15, [M Na] ), 613 (15, [M H] ), 612 (34, M ), 611 (20, [M À H] ), 610 (31, [M À 2 H] ), 556(15, [ M À
t-Bu) 2 H] ); 555 (41, [M À (t-Bu) H] ), 554 (100, [M À (t-Bu)] ), 534 (24), 509 (15), 468 (14), 428 (27),
411 (18), 410 (29), 404 (14), 230 ([MeC6H4CONHC4H3N2O H] ); 135 (only m/z > 130 were considered).
Data of 15a: UV (MeCN): 253 (16100), 309 (7200). 1H-NMR (CDCl3, 300 MHz): 1.05 (s, t-Bu); 1.76 1.98
(m, HÀC(3')), 2 HÀC(5')); 2.27 2.38 (m, 1 HÀC(2')); 2.86( dt, J 6 .0, 9.0, 1 HÀC(2')); 3.56 3.69
(m, CH2ÀC(3')); 3.81 (dd, J 5.0, 10.3, 2 HÀC(6')); 4.36( dt, J 3.5, 8.0, HÀC(4')); 6.08 (t, J 4.0,
HÀC(1')); 7.26 7.32 ( m, 2 H, to); 7.37 7.47 (m, 7 H, Ph2Si, HÀC(5)); 7.48 7.52 (m, 2 H, to); 7.58 7.63
(m, 4 H, Ph2Si); 7.89 (d, J 7.4, HÀC(6)); 8.33 (br., NH). 13C-NMR (CDCl3, 75 MHz): 19.21 (s, Me3C), 20.41
(q, Me (to)); 26.82 (q, Me3C); 36.18 (t, C(5')); 37.15 (t, C(2')); 44.61 (d, C(3')); 61.29 (t, C(6')); 62.90
(t, CH2ÀC(3')); 83.15 (d, C(4')); 88.65 (d, C(1')); 95.93 (d, C(5)); 126.21, 126.90 (2d, to); 127.88, 129.82 (2d,
Ph2Si); 131.51, 131.93 (2d, to); 132.62 (s, Ph2Si); 134.13 (s, Cipso (to)); 135.53 (d, Ph2Si); 137.81 (s, Co (to)); 144.11
(d, C(6)); 162.12 (s, CO). FAB-MS (NOBA; pos.): 634 (21, [M Na] ), 613 (44, [M H] ), 612 (100, M ),
554 (59, [M À (t-Bu)] ), 510 (14), 509 (31), 491 (29), 451 (20), 433 (15), 428 (18), 413 (16), 411 (19), 410 (17),
269, 230 ([MeC6H4CONHC4H3N2O H] ); 197, 135 (only m/z > 130 were considered).
N4-Benzoyl-1-{3'-{{[(tert-butyl)diphenylsilyl]oxy}methyl}-2',3',5'-trideoxy-b-d-erythro-hexofuranosyl}cyto-
sine (14b) and N4-Benzoyl-1-{3'-{{[(tert-butyl)diphenylsilyl]oxy}methyl}-2',3',5'-trideoxy-a-d-erythro-hexofur-
anosyl}cytosine (15b). As described for 14a/15a (Method 2), with 13b (1.94 g, 9 mmol) in HMDS (20 ml), and
Me3SiCl (3.8 ml, 30 mmol) for 8 h. Then with the pale yellow oil in 1,2-dichloroethane (15 ml), 10 (1.24 g,
3 mmol), 1,2-dichloroethane (10 ml), and TfOSiMe3 (1.64 ml, 9 mmol) for 4 h. After hydrolyzation with sat.
NaHCO3 soln. (20 ml), filtration through sea sand, and washing with CH2Cl2 (100 ml), the org. filtrate was
washed with brine (3 Â 20 ml), dried (Na2SO4), and evaporated and the remaining yellow foam chromato-
graphed (silica gel, AcOEt/petroleum ether 2 :1): 14b (681 mg, 38%) and 15b (792 mg, 44%). Colorless foams.
Data of 14b: [a]D20 66.73 (c 1.6, CHCl3). UV: 259 (24800), 308 (8000). IR (CHCl3): 3450 3360, 3070,
3030, 3000, 2960, 2930, 2890, 2860, 1710, 1660, 1620, 1550, 1480, 1430, 1390, 1360, 1310, 1300, 1260, 1110, 1070,
1040, 1000, 980, 940, 910 890, 820. 1H-NMR (CDCl3, 300 MHz): 1.06( s, t-Bu); 1.83 1.88 (m, HÀC(3')); 1.89
2.16( m, 2 HÀC(5')); 2.16 2.19 ( m, OH); 2.17 2.22 (m, 1 HÀC(2')); 2.45 2.55 (m, 1 HÀC(3')); 3.68 (d, J 5,
CH2ÀC(3')); 3.82 3.86(− dt, J 2, 7, 2 HÀC(6')); 4.15 (dt, J 3, 9, HÀC(4')); 6.04 (dd, J 2, 7, HÀC(1')); 7.37
7.47 (m, 7 arom. H); 7.48 7.54 (m, 2 H, bz); 7.58 7.65 (m, 5 H, Ph2Si, HÀC(5)); 7.88 7.92 (m, 2 H, bz); 8.03
(d, J 7, H ÀC(6)); 8.79 (br., NH). 13C-NMR (CDCl3, 75 MHz): 19.23 (s, Me3C); 26.87 (q, Me3C); 36.15
(t, C(5')); 37.16( t, C(2')); 44.57 (d, C(3')); 60.86 (t, C(5')); 62.96 (t, C(6')); 83.09 (d, C(4')); 87.63 (d, C(1')); 96.19
(d, C(5)); 127.54, 129.06(2 d, bz); 127.86, 129.94 (2d, Ph2Si); 132.95, 133.17 (2s, Ph2Si); 135.55 (d, Ph2Si); 143.87
(d, C(6)); 162.18 (s, CO). FAB-MS (NOBA; pos.): 620 ([M Na] ); 598 (M ), 540, 302, 295, 269 (3), 239
(5), 238 (9), 217 (27), 216 (100), 215 (6), 199 (23), 198 (5), 197 (19), 183 (6), 165 (6), 154 (8), 139 (9), 137 (17),
136 (15), 135 (45), 127 (27), 121 (7), 112 (6), 109 (8), 107 (7), 106 (6), 105 (52), 97 (7), 95 (8), 91 (11), 83 (9), 81
(14), 79 (8), 77 (15), 69 (8). Anal. calc. for C34H39N3O5Si: C 68.31, H 6.58, N 7.03; found: C 68.05, H 6.74, N 6.80.
Data of 15b: [a]D20 À41.32 (c 1.7, CHCl3). UV: 207 (45000), 260 (20500), 304 (7500). IR (CHCl3). 3450
3380, 3050, 3000, 2960, 2930, 2860, 1700, 1660, 1640, 1550, 1480, 1430, 1390, 1360, 1300, 1260, 1110, 1070, 1050,
1000, 970, 890, 820. 1H-NMR (CDCl3 , 300 MHz): 1.03 (s, t-Bu); 1.76 1.83 ( m, HÀC(3')); 1.83 1.97
(m, 2 HÀC(5')); 2.05 (m, OH); 2.26 2.38 ( m, 1 HÀC(2')); 2.85 (dt, J 6
,
9, 1 HÀC(2')); 3.57 3.69
(m, CH2ÀC(3')); 3.80 (t, J 5, 2 HÀC(6')); 4.35 (dt, J 3.5, 8, HÀC(4')); 6.04 (t, J 4, HÀC(1')); 7.36 7.46
(m, 6H, Ph 2Si); 7.49 7.52 (m, 3 H, bz, HÀC(5)); 7.58 7.64 (m, 4 H, Ph2Si); 7.87 7.90 (m, 3 H, bz, HÀC(6));
8.76(br., NH). 13C-NMR (CDCl3, 100 MHz): 19.21 (s, Me3C); 26.86 (q, Me3C); 36.56 (t, C(5')); 37.19 (t, C(2'));
46.38 (d, C(3')); 60.32 (t, CH2ÀC(3')); 63.19 (t, C(6')); 81.94 (d, C(4')); 88.03 (d, C(1')); 96.33 (d, C(5)); 127.55