J.-B. Behr et al. / Tetrahedron 59 (2003) 543–553
549
2.7 mmol, 1.7 equiv.), the OsO4 solution (2 ml) in acetone
(1.5 ml) and H2O (1 ml) for one day. Standard work-up gave
7a (0.22 g, 40%).
resulting crystals were washed with iPr2O to give 8a (0.26 g,
quantitative).
Compound 8a. Colorless crystals. Mp 1768C (AcOEt/
iPr2O). [a]2D0¼þ6 (c¼0.4, CHCl3). IR (KBr): 2980, 1728,
1705, 1440, 1408, 1390, 1378, 1362, 1270, 1242, 1232,
1212, 1160, 1140, 1100, 972, 720. 1H NMR (CDCl3)
Table 1. 13C NMR (CDCl3, 300 K): 24.5 (C(40)); 26.2 (Me);
27.6 (CMe3); 27.7 (Me); 29.6 (C(30)); 46.3 (C(3)); 58.6
(C(50)); 68.0 (CH2Ph); 71.3, 70.9 (C(4), C(5)); 82.1 (C(6));
82.5 (CMe3); 110.3 (CMe2); 135.8, 128.6, 128.4, 128.2
(Ph); 156.5 (CO–N(2)); 171.3 (CO–C(50)); 176.0 (CO(20)).
Anal. calcd for C24H32N2O8 (476.51): C 60.49, H 6.77, N
5.88; found: C 60.5, H 6.9, N 5.9.
Compound 7a. Colorless crystals. Mp 1718C (AcOEt/Et2O).
[a]2D0¼þ31 (c¼0.85, CHCl3). IR (KBr): 3480, 3350, 2950,
1730, 1700, 1635, 1390, 1380, 1270, 1230, 1200, 1100, 995,
980. 1H NMR (CDCl3): Table 1. Anal. calcd for
C13H21N3O7 (331.32): C 47.13, H 6.39, N 12.68; found: C
47.4, H 6.4, N 12.7.
4.2.2. t-Butyl (4S)-t-6-[(50S)-50-(t-butyloxycarbonyl)-20-
oxo-pyrrolidine-10-yl]-r-4,c-5-dihydroxy-1,2-oxazinane-
2-carboxylate (7b). General procedure with compound 5b
(1.8 g, 4.9 mmol) in acetone (10 ml) and water (2 ml), 5 M
aqueous NMO solution (1.8 ml, 9 mmol, 2 equiv.) and the
OsO4 solution (2.4 ml and again 2.4 ml after 8 h) for
one day. Standard work-up gave a mixture of 7b and 5b
(2.1 g) which was resolved by FC (AcOEt/cyclohexane,
8:2) and gave successively 5b 0.30 g, 16%) and 7b (1.50 g,
75%). 7b crystallised difficulty, but easily in AcOEt as
solvate.
4.2.5. Benzyl (3S)-c-6-[(50S)-50-(t-butyloxycarbonyl)-20-
oxo-pyrrolidine-10-yl]-t-4,t-5-dihydroxy-r-3-methyl-1,2-
oxazinane-2-carboxylate (7d). General procedure with
compound 5d (3.61 g, 8.7 mmol), NMO (2.34 g,
17.4 mmol, 2 equiv.) and the OsO4 solution (7.1 ml) in
acetone (14 ml) and H2O (3.5 ml) for 16 h at 408C. Standard
work-up and filtration over a bed of silica gel (AcOEt) gave
7d (3.87 g, 99%) which was characterised as its acetonide
8b.
Compound 7b. Colorless crystals. Mp 118–1228C (Et2O/
iPr2O) or 80–858C (solvated with 1 mol AcOEt).
[a]2D0¼222 (c¼1, CHCl3). IR (KBr): 3470, 3330, 2965,
1700, 1450, 1390, 1365, 1245, 1273, 1240, 1225, 1158,
1118, 985, 898, 860, 820, 760; solvated with AcOEt: 3500,
3370, 2980, 1735, 1722, 1690, 1395, 1368, 1335, 1285,
1243, 1220, 1150, 1130, 1095, 1035, 970, 938, 815, 800. 1H
NMR (CDCl3): Table 1. 13C NMR (CDCl3, 300 K): 24.9
(C(40)); 27.8, 28.0 (2 CMe3); 29.2 (C(30)); 50.4 (C(3)); 56.2
(C(50)); 66.8, 67.9 (C(4), C(5)); 78.9 (C(6)); 82.4, 84.0 (2
CMe3); 156.2 (CO–N(20)); 174.1 (CO–C(50)); 176.4
(CO(20)). Anal. calcd for C18H30N2O8 (402.45): C 53.72,
H 7.51, N 6.96; found C 53.9, H 7.7, N 6.9; calcd for
C18H30N2O8þC4H8O2 (solvate, 490.56): C 53.87, H 7.81, N
5.71; found: C 53.7, H 7.8, N 5.8.
Compound 7d. Colorless resin. [a]2D0¼232 (c¼1, CHCl3).
IR (KBr): 3460, 2975, 1718, 1708, 1401, 1370, 1300, 1325,
1141. 1H NMR (CDCl3): Table 1. 13C NMR (CDCl3,
300 K): 14.4 (Me–C(3)); 24.8 (C(40)); 27.8 (CMe3)); 29.3
(C(30)); 55.4 (C(3)); 56.6 (C(50)); 65.0 C(5)); 68.0 (CH2Ph);
70.7 C(4); 80.4 (C(6)); 83.8 (CMe3); 136.0, 128.4, 128.2,
128.0 (Ph); 156.3 (CO–N(2)); 173.9 (CO–C(50)); 176.5
(C(20)).
4.2.6. Acetonide 8b. A solution of 7d (0.44 g, 0.99 mmol)
in acetone (6 ml) and 2,2-dimethoxypropane (1.4 ml) was
stirred with Amberlyst-15 (Hþ) (in beads, 57 mg) for 4 h at
408C, then filtered and evaporated. The resulted crystals
were washed with iPr2O to give 8b (0.43 g, 89%).
4.2.3. Benzyl (4S)-t-6-[(50S)-50-(t-butyloxycarbonyl)-20-
oxo-pyrrolidine-10-yl]-r-4,c-5-dihydroxy-1,2-oxazinane-
2-carboxylate (7c). General procedure with compound 5c
(2.4 g, 6 mmol), NMO (1.61 g, 12 mmol, 2 equiv.) and the
OsO4 solution (4.8 ml) in acetone (9.6 ml) and H2O (2.4 ml)
for one day. Standard work-up gave 7c (2.42 g, 93%) as a
colorless resin which crystallised with difficulty.
Compound 8b. Colorless crystals. Mp 1338C (AcOEt/
iPr2O). [a]2D0¼þ20 (c¼0.55, CHCl3). IR (KBr): 2981,
1709, 1415, 1303, 1278, 1222, 1170, 1142, 1119, 1091,
1075, 1028, 996, 754. H NMR (CDCl3): Table 1. Anal.
calcd for C25H34N2O8 (490.54): C 61.21, H 6.99, N 5.71;
found: C 61.2, H 7.0, N 5.7.
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Compound 7c. Colorless crystals. Mp 126–1288C (AcOEt).
[a]1D8¼233 (c¼1, CHCl3). IR (KBr): 3445, 2980, 1735,
1715, 1460, 1392, 1370, 1332, 1282, 1258, 1205, 1150,
4.3. Hydrogenolysis to aminoalditols
4.3.1. 1-[(N,N-Dimethylcarbamoyl)-amino]-1-deoxy-D-
erythritol (D-9a). Compound 7a (0.24 g, 0.72 mmol) was
hydrogenated at rt in MeOH (5 ml) over Raney-Ni (wet
1.2 g) for 5–6 h. The solution was filtered over celite and
evaporated. The resulting oily crystals were washed with
hot AcOEt to give D-9a (0.12 g, 90%). The AcOEt solution
contained the methyl L-pyroglutamate 10a (0.105 g, quant.)
which was identified by its NMR data.
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1137, 1093, 1050, 963, 820, 752, 700. H NMR (CDCl3):
Table 1. 13C NMR (CDCl3, 300 K): 24.8 (C(40)); 27.7
(CMe3); 29.2 (C(30)); 50.6 (C(3)); 56.4 (C(50)); 66.4, 67.7,
67.9, (C(4), C(5), CH2Ph); 79.7 (C(6)); 83.7 (CMe3); 135.8,
128.2, 128.1, 127.9 (P0h); 156.5 (CO–N(2)); 173.7
(CO–C(50)); 176.6 (CO(2 )). Anal. calcd for C21H28N2O8
(426.37): C 57.79, H 6.47, N 6.57; found: C 57.8, H 6.5, N
6.4.
Compound D-9a. Colorless crystals. Mp 1308C (MeOH/
Et2O). [a]2D0¼þ8.9 (c¼1, MeOH). IR (KBr): 3350, 3300,
3200, 2930, 1625, 1450, 1380, 1350, 1255, 1245, 1060,
1040. H NMR (D2O, 300 K): 2.87 (s, NMe2), 3.23 (dd,
Ha–C(4)), 3.40 (dd, Hb–C(4)), 3.60 (m, Ha–C(1), H–C(2),
4.2.4. Acetonide 8a. A solution of 7c (0.24 g, 0.55 mmol) in
acetone (3.2 ml) and 2,2-dimethoxypropane (0.7 ml,
5.8 mmol) was stirred with Amberlyst-15 (Hþ) (in beads,
30 mg) for 4 h at 358C, then filtered and evaporated. The
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