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Helvetica Chimica Acta Vol. 87 (2004)
Data of 27a: TLC (Et2O/hexane 8 :2): Rf 0.32. IR (CHCl3): 2990, 2960, 2930, 2900, 2860, 1740, 1600, 1470,
1465, 1440, 1385, 1375, 1260, 1175, 1160, 1140, 1075, 1000, 975, 940, 900, 840, 815. 1H-NMR (CDCl3): 0.07
(s, Me2Si); 0.90 (s, tBuSi); 1.35 (s, 3 H, Me2CO2); 1.54 (s, 3 H, Me2CO2); 1.67 (br. s, NH2); 3.57 (d, J 3.2,
HÀC(2)); 3.72 (dd, J 3.5, Jgem 11.2, 1 H, CH2(5')); 3.75 (s, MeO); 3.80( dd, J 3.3, Jgem 11.2, 1 H, CH2(5'));
3.98 (ddd(dt), J 3.4, 4.6, HÀC(4')); 4.41 (dd(t), J 3.4, HÀC(1')); 4.67 (dd, J 4.6, 6.4, HÀC(3')); 4.82
(dd, J 3.6, 6.4, HÀC(2')); NOE data were used to assign configuration. 13C-NMR (CDCl3): À5.50( q, MeSi);
À5.41 (q, MeSi); 18.39 (s, Me3CSi); 25.64 (q, Me2CO2); 25.90( q, Me3CSi); 27.61 (Me2CO2); 52.25 (q, MeO);
56.46 (d, NCHCO2Me); 63.06 (t, SiOCH2); 80.90, 82.42, 84.68, 85.17 (4d, C(1'), C(2'), C(3'), C(4')); 113.72
(s, Me2CO2); 174.12 (s, CO2Me). GC/MS (P15020): tR 5.6; 360, 318, 287, 242, 200, 171, 129, 73 (100). MS: 377
t
(12), 376 (49, [M 1] ); 360(13, [ M À Me] ), 319 (20), 318 (98, [M À Bu), 317 (17), 316 (19), 288 (10), 287 (48,
t
[M À NH2CHCO2Me] ), 286 (12), 260(16, [ M À BuMe2Si] ), 229 (10), 200 (10), 187 (13), 172 (10), 171 (17),
159 (10), 143 (10), 131 (12), 130 (16), 129 (81), 128 (14), 126 (10), 117 (55), 116 (18), 115 (23), 114 (11), 101
(27), 97 (24), 89 (39), 88 (51), 85 (16), 84 (10), 81 (10), 75 (72), 74 (12), 73 (100), 70 (11), 69 (16), 59 (42), 58
(14), 57 (25), 56 (13), 55 (23), 43 (35), 41 (21), 33 (14).
Data of 27b: TLC (Et2O/hexane 8 :2): Rf 0.24. IR (CHCl3): 2990, 2960, 2930, 2900, 2860, 1740, 1600, 1470,
1465, 1440, 1385, 1375, 1260, 1175, 1160, 1140, 1080, 1010, 975, 860, 840, 815. 1H-NMR (CDCl3): 0.07 (s, Me2Si);
0.90 (s, tBuSi); 1.34 (s, 3 H, Me2CO2); 1.53 (s, 3 H, Me2CO2); 1.64 (br. s, NH2); 3.72 (dd, J 3.5, Jgem 11.2, 1 H,
CH2(5')); 3.73 (d, J 5.9, HÀC(2)); 3.75 (s, MeO); 3.78 (dd, J 3.2, Jgem 11.2, 1 H, CH2(5')); 4.03 (q-like m,
J 3.3, HÀC(4')); 4.18 (dd-like m, J 3.1, 5.8, HÀC(1')); 4.64, 4.65 (2m, HÀC(2'), HÀC(3')); NOE data were
used to assign configuration. 13C-NMR (CDCl3): À5.50( q, MeSi); À5.41 (q, MeSi); 18.42 (s, Me3CSi); 25.61
(q, Me2CO2); 25.94 (q, Me3CSi); 27.54 (Me2CO2); 52.12 (q, MeO); 56.46 (d, NCHCO2Me); 63.42 (t, SiOCH2);
81.28, 82.06, 85.10, 85.75 (4d, C(1'), C(2'), C(3'), C(4')); 113.72 (s, Me2CO2); 173.35 (s, CO2Me). MS: 3.77 (4),
t
376 (16, [M 1] ), 360(13, [ M À Me] ), 319 (12), 318 (62, [M À Bu] ), 316 (12), 288 (12), 287 (56, [M À
t
NH2CHCO2Me), 260(30, [ M À BuMe2Si] ), 229 (11), 187 (15), 172 (18), 172 (12), 170 (20), 143 (12), 136 (10),
133 (11), 131 (10), 130 (15), 129 (92), 117 (52), 116 (12), 115 (21), 114 (12), 101 (28), 97 (22), 89 (37), 88 (62),
85 (17), 84 (10), 81 (11), 75 (72), 74 (11), 73 (100), 70 (11), 69 (15), 59 (39), 58 (13), 57 (24), 56 (12), 55 (22), 43
(33), 41 (19), 33 (14).
2-{5-O-[(tert-Butyl)dimethylsilyl]-2,3-O-isopropylidene-b-d-ribofuranosyl}glycinamide (28a/b). Meth-
od A, by Removal of the Z-Group from 26a/b: To a soln. of 26a/b (6.84 g, 13.8 mmol) in MeOH (80ml) was
added Pd/C (6.9 g). The mixture was stirred for 48 h under H2 at r.t. The mixture was filtered through a bed of
Celite, which was washed with MeOH. The filtrate and washings were evaporated. FC (silica gel, CH2Cl2/MeOH
95 :5) of the residue yielded 28a/b (4.45 g, 89%) as a colorless oil. The reaction proceeded without
epimerization.
Method B, by Aminolysis of 27a/b: A soln. of 27a/b (1.132 g, 3.015 mmol) in MeOH (30 ml) in a glass tube
was saturated at 08 with NH3 gas. The tube was sealed and the mixture stirred for 2 d at r.t. The mixture was
evaporated and the residue purified by FC (silica gel, CH2Cl2/MeOH 95 :5): 28a/b (1.082 g, quant.) as a colorless
oil. The reaction proceeded without epimerization.
Data of 28a: TLC (CH2Cl2/MeOH 9 :1): Rf 0.44. IR (CHCl3): 3500, 3380, 3000, 2960, 2935, 2860, 1685, 1590,
1
1550, 1470, 1465, 1385, 1375, 1260, 1160, 1135, 1080, 1005, 980, 970, 905, 860, 840, 815. H-NMR (CDCl3): 0.07
(s, MeSi); 0.08 (s, MeSi); 0.90 (s, tBuSi); 1.35 (s, 3 H, Me2CO2); 1.54 (s, 3 H, Me2CO2); 1.77 (br. s, NH2); 3.52
(d, J 3.9, HÀC(2)); 3.75 (dd, J 2.6, Jgem 11.3, 1 H, CH2(5')); 3.86 (dd, J 2.7, Jgem 11.3, 1 H, CH2(5')); 4.04
(ddd(dt), J 2.6, 3.9, HÀC(4')); 4.36 (dd(t), J 4.1, HÀC(1')); 4.63 (dd, J 4.4, 6.6, HÀC(2')); 4.69
(dd, J 4.0, 6.7, HÀC(3')); 5.49 (br. s, 1 H of CONH2); 7.31 (br. s, 1 H of CONH2). 13C-NMR (CDCl3): À5.50
(q, MeSi); À5.41 (q, MeSi); 18.42 (s, Me3CSi); 25.61 (q, Me2CO2); 25.93 (q, Me3CSi); 27.54 (Me2CO2); 55.97
(d, NCHCONH2); 63.02 (t, SiOCH2); 80.83, 82.09, 84.59, 84.78 (4d, C(1'), C(2'), C(3'), C(4')); 114.21
(s, Me2CO2); 175.19 (s, CONH2). GC/MS (P1001020): tR 9.4. GC/MS (P10010): tR 15.1; 360, 345, 318, 303, 245,
171, 97, 73 (100). MS: 362 (4), 361 (5), 318 (11), 317 (36), 316 (57), 305 (24), 304 (51), 303 (53), 287 (22), 259
(11), 258 (21), 245 (10), 171 (39), 131 (10), 130 (12), 129 (55), 126 (10), 117 (39), 116 (11), 115 (18), 101 (18), 98
(11), 97 (25), 89 (35), 85 (16), 76 (10), 75 (70), 74 (23), 73 (100), 70 (10), 69 (12), 59 (33), 58 (13), 57 (20), 56
(11), 55 (16), 43 (23), 41 (14).
Data of 28b: TLC (CH2Cl2/MeOH 9 :1): Rf 0.43. IR (CHCl3): 3500, 3380, 3010, 2950, 2930, 2900, 2880, 2860,
1685, 1585, 1555, 1470, 1460, 1385, 1375, 1255, 1160, 1135, 1080, 1005, 970, 935, 860, 835, 810. 1H-NMR (CDCl3):
0.08 (s, MeSi); 0.09 (s, MeSi); 0.91 (s, tBuSi); 1.35 (s, 3 H, Me2CO2); 1.53 (s, 3 H, Me2CO2); 1.77 (br. s, NH2); 3.52
(d, J 6.7, HÀC(2)); 3.73 (dd, J 3.3, Jgem 11.3, 1 H, CH2(5')); 3.83 (dd, J 2.8, Jgem 11.3, 1 H, CH2(5')); 4.11
(m, HÀC(4'), HÀC(1')); 4.64 (dd, J 3.6, 6.5, HÀC(2')*); 4.75 (dd, J 4.0, 6.5, HÀC(3')*); 5.7 (br. s, 1 H of
CONH2); 6.9 (br. s, 1 H of CONH2). 13C-NMR (CDCl3): À5.48 (q, MeSi); À5.37 (q, MeSi); 18.39 (s, Me3CSi);