Helvetica Chimica Acta ± Vol. 82 (1999)
2405
8.20 mmol), stirred for 44 h, diluted with AcOEt (50 ml), and suction-filtered over a Celite/sand bed.
Evaporation and FC (toluene/AcOEt 10 : 1) of the amber-coloured oil (1.43 g) gave 39 (920 mg, 78%). Weakly
yellowish oil. An anal. sample was obtained by HPLC (toluene/Et2O 10 : 1). Rf (toluene/AcOEt 10 : 1) 0.23.
[a]2D5
3.0 (c 0.94, CHCl3). IR (CHCl3): 3420w, 3230w, 3060w, 3020w, 2920w, 2860w, 1760s, 1730s, 1515s,
1
1455m, 1385w, 1370w, 1249s, 1180s, 1170s, 1115m, 1095s, 830m, 700m. H-NMR (400 MHz, (D6)acetone): see
Table 3; additionally, 3.74 (s, MeO); 4.39, 4.660 (2d, J 11.1, PhCH2); 4.51 (s, PhCH2); 4.665, 4.715 (2d, J 11.9,
PhCH2); 6.79 ± 6.82 (m), 6.99 ± 7.02 (m) (AA'BB'); 7.11 ± 7.39 (m, 15 arom. H); 9.21 (d, J 8.9, exchange with
D2O, NH). 13C-NMR (50 MHz, (D6)acetone): see Table 4; additionally, 55.70 (q, MeO); 72.68, 73.69, 74.58 (3t,
3 PhCH2); 114.57 (2d); 121.74 (2d); 128.24 ± 129.09 (several d); 131.95 (s); 138.90, 139.29, 139.53 (3s); 157.77
(s). CI-MS (NH3): 666 (8, [M NH4] ), 651 (8), 650 (40), 649 (100, [M 1] ), 496 (12), 419 (9). Anal. calc.
for C36H35F3N2O6 (648.68): C 66.66, F 8.79, N 4.32; found: C 66.50, F 8.61, N 4.29.
2,3-Dideoxy-3-[(4-methoxyphenyl)amino]-2-(trifluoroacetamido)-d-mannono-1,3-lactam (40). A suspen-
sion of 10% Pd/C (60 mg) in dioxane/H2O 1 :1 (5 ml) was hydrogenated, treated with soln. of 39 (171 mg,
0.263 mmol) in dioxane/H2O 1:1 (6.5 ml), vigorously stirred under 7.5 bar of H2 for 7 h, treated with MeOH
(3 ml) and 20% Pearlmanꢀs catalyst (80 mg), and stirred under 7.5 bar of H2 for 135 h. The mixture was diluted
with EtOH, and repeatedly treated with Celite and centrifuged (EtOH was used to suspend the residue after
each centrifugation cycle). Evaporation of the combined supernatants and FC (CH2Cl2/MeOH 12 :1) gave 40
(91 mg, 91%). Colourless oil. Rf (CH2Cl2/MeOH 10 :1) 0.32. [a]D25
20.0 (c 0.80, CHCl3). IR (CHCl3): 3605w,
3350m (br.), 2980w, 2940w, 2820w, 1750m, 1712s, 1515s, 1360m, 1250m, 1175m, 1015s, 832w. 1H-NMR (400 MHz,
(D6)acetone): see Table 3; 3.53 (qd, J ꢀ 5.0, 9.0, addition of D2O ! 3.46, ddd, J 3.7, 5.0, 9.0, H C(5)); 3.62
(br. dd, J ꢀ 5.0, 11.0, addition of D2O ! 3.57, dd, J 5.1, 11.4, H C(6)); 3.70 ± 3.78 (m, addition of D2O ! 3.68,
dd, J 5.1, 11.4, H' C(6)); 3.76 (s, MeO); 3.80 ± 3.87 (br. s, exchange with D2O, HO C(6)); 3.93 (ddd, J 3.3,
6.7, 8.8, addition of D2O ! 3.87, dd, J 3.4, 9.0, H C(4)); 4.03 (d, J 5.7, exchange with D2O, HO C(5)); 4.56
(d, J 6.8, exchange with D2O, HO C(4)); 4.66 (dd, J 2.6, 3.2, H C(3)); 5.15 (br. s, addition of D2O ! 4.98,
d, J 2.3, H C(2)); 6.86 ± 6.90 (m), 7.49 ± 7.53 (m) (AA'BB'); 9.16 (br. s, exchange with D2O, NH). 1H-NMR
(400 MHz, CD3OD): 3.42 (ddd, J 3.3, 5.4, 9.1, H C(5)); 3.55 (dd, J 5.3, 11.4, H C(6)); 3.69 (dd, J 3.3,
11.3, H' C(6)); 3.77 (s, MeO); 3.81 (dd, J 3.3, 9.1, H C(4)); 4.62 (dd, J 2.3, 3.3, H C(3)); 5.01 (d, J 2.3,
H
C(2)); 6.89 ± 6.93 (m), 7.46 ± 7.50 (m) (AA'BB'). 13C-NMR (CD3OD, 50 MHz): see Table 4, additionally,
55.88 (q, MeO); 115.01 (2d); 123.06 (2d); 131.61, 158.71 (2s). CI-MS (NH3): 397 (15), 396 (100, [M NH4] ),
380 (13), 379 (90, [M 1] ), 378 (10). Anal. calc. for C15H17F3N2O6 (378.31): C 47.62, H 4.53, F 15.07, N 7.40;
found: C 47.67, H 4.69, F 14.84, N 7.20.
2-Azido-4,5,6-tri-O-benzyl-3-{[(benzyloxycarbonyl)methyl]amino}-2,3-dideoxy-d-mannono-1,3-lactam (41).
Under Ar, a soln. of 31a (202 mg, 0.43 mmol) in dry 1,3-dimethylimidazolidin-2-one (10 ml) was treated with 3-
molecular sieves (300 mg), freshly prepared Ag2O [106] (99 mg, 0.43 mmol), and benzyl bromoacetate
(98 mg, 0.43 mmol), and stirred in the dark at 248 for 24 h and then at 408 for 64 h. After the addition of more
Ag2O (50 mg, 0.21 mmol) and benzyl bromoacetate (49 mg, 0.21 mmol), stirring was continued at 508 for 32 h.
The same amounts of both reagents and 3- molecular sieves (250 mg) were added, and the suspension was
stirred at 608 for 24 h. The same amounts of reagents were added a third time, and the suspension was stirred at
758 for 50 h. The suspension was cooled to 188 and suction-filtered over a Celite/sand bed (washing with 100 ml
of AcOEt). Evaporation of the clear, weakly yellowish filtrate and FC (toluene/AcOEt 25 :1) gave 41 (205 mg,
77%). Colourless oil. Rf (toluene/AcOEt 15 :1) 0.28. [a]D25
74.7 (c 0.61, CHCl3). IR (CHCl3): 3060w, 3030w,
3005w, 2960w, 2950w, 2930w, 2870w, 2115s, 1770s, 1748s (sh), 1495m, 1455m, 1410m, 1385m, 1355w, 1260m,
1
1189s, 1095s (br.), 1030s, 700s. H-NMR (400 MHz, (D6)acetone): see Table 3; additionally, 3.97 (d, J 18.1),
4.23 (d, J 18.0) (CH2N); 4.51, 4.74 (2d, J 11.5, PhCH2); 4.54, 4.57 (2d, J 12.1, PhCH2); 4.67, 4.72 (2d, J
12.0, PhCH2); 5.00, 5.05 (2d, J 12.3, PhCH2); 7.24 ± 7.38 (m, 20 arom. H). 1H-NMR (400 MHz, CD3OD): 3.58
(dd, J 5.1, 10.4, H C(6)); 3.61 (dd, J 5.5, 10.4, H' C(6)); 3.82 (dt, J ꢀ 3.2, 5.1, H C(5)); 3.91 (dd, J 3.2,
6.7, H C(4)); 3.95, 4.21 (2d, J 18.0, CH2N); 4.00 (dd, J 2.1, 6.8, H C(3)); 4.32 (d, J 2.1, H C(2)); 4.37,
4.60 (2d, J 11.5, PhCH2); 4.47, 4.52 (2d, J 11.9, PhCH2); 4.55, 4.61 (2d, J 12.0, PhCH2); 4.97, 5.03 (2d, J
12.2, PhCH2); 7.18 ± 7.37 (m, 20 arom. H). 13C-NMR (50 MHz, (D6)acetone): see Table 4; additionally, 67.28
(t, PhCH2); 72.88 (t, 2 PhCH2); 73.75 (t, PhCH2); 128.33 ± 129.17 (several d); 136.50, 138.90, 139.12, 139.25 (4s);
168.63 (s, CO). CI-MS (NH3): 623 (7), 622 (32), 621 (78, [M 1] ), 610 (12), 595 (12), 594 (41), 593 (100,
[M 1 N2] ), 575 (6), 533 (12), 507 (24), 506 (70), 488 (7), 487 (7), 486 (13), 485 (36), 430 (8), 418 (8), 399
(22), 398 (86), 377 (8), 340 (14), 323 (23), 108 (30), 91 (12, Bn ). Anal. calc. for C36H36N4O6 (620.71): C 69.66,
H 5.85, N 9.03; found: C 69.68, H 5.78, N 9.20.
4,5,6-Tri-O-benzyl-3-{[(benzyloxycarbonyl)methyl]amino}-2,3-dideoxy-2-(trifluoroacetamido)-d-mannono-
1,3-lactam (42). At 258 and under Ar, a soln. of 41 (538 mg, 0.866 mmol) in dry THF (7.5 ml) was treated with