S. Hanessian et al. / Tetrahedron 59 (2003) 983–993
991
1H), 2.27 (m, 1H), 1.92 (m, 1H), 1.92 (s, 1H), 1.78 (s, 24H)
1.62 (m, 1H); 13C NMR (100 MHz, D2O) d 182.1, 101.6,
93.5, 83.6, 83.1, 82.9, 82.7, 77.6, 74.1, 73.6, 71.8, 69.4,
66.1, 65.9, 64.8, 60.2, 55.5, 53.9, 50.5, 49.3, 48.4, 46.6,
45.7, 40.6, 40.5, 40.1, 30.2, 30.0, 29.9, 25.3, 24.0; [a]D¼
þ25 (c 1.0, H2O); MALDI-FTMS calcd for C23H50N8O9Na
(MþNaþ) 605.3593; found 605.3601.
2.3.5. Compound 9h. (quant.); 1H NMR (400 MHz, D2O) d
5.36 (s, 1H), 5.21 (s, 1H), 4.10–3.17 (m, 22H), 3.10–3.05
(m, 4H), 2.95–2.80 (m, 6H), 2.40–2.20 (m, 2H), 2.10–1.95
(m, 1H), 1.91 (s, 24H), 1.80–1.60 (m, 1H); 13C NMR
(75 MHz, D2O) d 182.1, 101.1, 94.3, 83.5, 82.3, 78.2, 74.0,
72.4, 69.5, 65.9, 65.4, 60.2, 55.7, 52.5, 51.3, 50.8, 49.4,
48.7, 40.5, 37.3, 31.5, 31.3, 31.0, 24.0; [a]D¼þ21 (c 0.90,
H2O); MALDI-FTMS calcd for C24H53N8O9 (MþHþ)
597.3930; found 597.3938.
1H), 2.10 (m, 2H), 1.90 (m, 1H); 13C NMR (75 MHz, D2O)
d 163.5, 163.0, 157.4, 118.6, 114.7, 101.1, 93.2, 83.6, 82.0,
78.4, 77.4, 74.3, 68.8, 65.8, 63.1, 54.9, 52.2, 49.6, 48.5,
47.4, 38.5, 36.9, 27.9; [a]D¼þ33 (c 1.1, H2O); MALDI-
FTMS calcd for C26H57N12O9 (MþHþ) 681.4366; found
681.4361.
2.4.4. Compound 9j. (quant.); 1H NMR (400 MHz, D2O) d
5.26 (s, 1H), 5.08 (s, 1H), 4.50–3.10 (m, 30H), 2.40 (m,
1H), 2.10 (m, 2H), 1.89 (m, 1H); 13C NMR (100 MHz, D2O)
d 163.9, 163.5, 163.1, 157.0, 118.2, 115.3, 101.4, 93.3, 83.1,
82.2, 78.5, 77.4, 74.4, 68.7, 68.5, 66.3, 63.1, 61.3, 57.5,
54.6, 52.6, 49.7, 48.5, 47.4, 43.1, 38.4, 27.9, 23.1; [a]D¼
þ33 (c 1.1, H2O); MALDI-FTMS calcd for C25H52N7O9
(MþHþ) 622.3882; found 622.3882.
2.4.5. Compound 10. A solution of 7 (200 mg, 0.148 mmol)
in MeOH (2 mL) was cooled at 08C and treated with NaBH4
(22 mg, 0.590 mmol). The mixture was stirred for 15–
20 min, few drops of AcOH were added to quench the
reaction and the mixture was warmed to rt. The solvents
were removed under vacuum, the residue was dissolved in
EtOAc, washed with water, brine and dried over Na2SO4.
The solvent was removed under vacuum and the crude solid
purified by flash chromatography (CH2Cl2/acetone, 85:15)
to give 10 (152 mg, 76%) as a white solid; 1H NMR
(400 MHz, CDCl3) d 7.40–7.20 (m, 25H), 5.60–5.40 (m,
4H), 5.30–4.70 (m, 16H), 4.60 (m, 1H), 4.40–4.20 (m, 2H),
4.00–3.25 (m, 13H), 3.05 (m, 1H), 2.85 (m, 1H), 2.08 (s,
3H), 2.00 (s, 3H), 1.84 (s, 6H), 1.70 (m, 1H); 13C NMR
(75 MHz, CDCl3) d 171.2, 170.6, 157.3, 156.7, 156.4,
155.9, 136.9, 136.8, 136.7, 129.1, 129.0, 128.8, 128.6,
128.3, 128.2, 128.0, 95.8, 94.9, 84.6, 70.9, 68.9, 68.7, 67.5,
67.2, 67.0, 62.5, 61.7, 52.1, 51.7, 50.2, 49.3, 42.7, 35.6,
30.9, 21.2, 20.8; [a]D¼þ67 (c 1.4, CHCl3); FAB m/z calcd
(MþHþ) 1350.5; found 1350.4.
2.3.6. Compound 9i. (quant.); 1H NMR (400 MHz, D2O) d
5.30 (s, 1H), 5.05 (s, 1H), 3.92–3.00 (m, 24H), 2.75–2.52
(m, 8H), 2.17 (m, 2H), 1.88 (m, 1H), 1.76 (s, 21H) 1.55 (m,
1H); 13C NMR (100 MHz, D2O) d 181.7, 92.9, 82.7, 81.9,
77.0, 73.7, 71.9, 69.0, 66.5, 65.7, 64.8, 60.2, 57.0, 55.1,
50.4, 50.1, 48.7, 48.1, 43.1, 40.0, 30.7, 30.3, 23.5; [a]D¼
þ35 (c 1.0, H2O); MALDI-FTMS calcd for C24H49N7O9Na
(MþNaþ) 602.3484; found 602.3471.
2.4. General procedure for deprotection (9d,e, 9g and 9j)
The appropriate pseudo-disaccharide was treated with a
catalytic amount of NaOMe in MeOH (2 mL). The reaction
mixture was stirred at room temperature until completion
(approximately 2 h) then reaction mixture was neutralized
by addition of Amberlite IR-120(Hþ), the resin was filtered
off and the filtrate was evaporated to dryness The resulting
residue was dissolved in TFA (2 mL), stirred for 2 h and
concentrated under vacuum. To the resulting residue in
AcOH (80% in H2O, 2 mL), was added 10% Pd/C
(approximately 10 mg) and the mixture was stirred under
1 atm of hydrogen overnight. The mixture was filtered
through a Celite pad, concentrated under vacuum, diluted
with water and lyophilized to afford (9d,e, 9g and 9j) as
fluffy white solids.
2.4.6. Compound 11. To a suspension of 10 (50 mg,
0.037 mmol), tris(N,N0,N00-benzyloxycarbamate)guanidine15
(40 mg, 0.11 mmol) and PPh3 (15 mg, 0.056 mmol) in
toluene (1.5 mL) was added slowly diethylazodicarboxylate
(8.7 mL, 0.056 mmol). The mixture was heated at 708C
during 1 h, cooled down at room temperature and
concentrated under vacuum. The resulting residue was
purified by flash chromatography (EtOAc/hexanes, 45:55)
to give 11 (51 mg, 77%) as a white solid; 1H NMR
(400 MHz, CDCl3) d 7.35–7.20 (m, 40H), 5.80 (m, 1H),
5.50 (m, 2H), 5.35–5.76 (m, 20H), 4.45 (m, 2H), 4.25–3.30
(m, 12H), 3.00 (m, 2H), 2.20 (m, 2H), 2.05 (m, 3H), 1.99 (m,
3H), 1.89 (s, 3H), 1.74 (s, 3H); 13C NMR (100 MHz,
CDCl3) d 170.4, 169.9, 169.7, 156.7, 155.7, 155.6, 155.5,
154.4, 136.6, 136.3, 134.4, 128.5, 128.4, 128.3, 128.0,
127.9, 127.8, 127.6, 95.7, 94.9, 70.1, 69.2, 68.5, 68.2, 67.8,
66.7, 66.5, 66.2, 61.8, 51.9, 49.3, 49.0, 41.6, 29.9, 29.5,
20.7, 20.5, 20.4, 20.1; [a]D¼þ62 (c 1.0, CHCl3); FAB m/z
calcd (MþHþ) 1793.7; found 1793.8.
2.4.1. Compound 9d. (quant.); 1H NMR (400 MHz, D2O) d
5.33 (s, 1H), 5.20 (s, 1H), 4.30 (m, 1H), 4.20–3.15 (m,
22H), 2.50 (m, 1H), 2.20 (m, 1H), 1.85 (s, 1H), 1.25 (m,
1H); 13C NMR (75 MHz, D2O) d 164.0, 163.5, 163.1, 162.6,
157.6, 122.5, 118.6, 114.7, 110.9, 101.5, 93.3, 82.6, 78.3,
77.3, 74.1, 68.7, 66.8, 63.1, 61.7, 54.5, 49.7, 48.5, 47.4,
46.9, 38.4, 38.1, 28.0, 27.8; [a]D¼þ27 (c 1.0, H2O);
MALDI-FTMS calcd for C23H49N9O9Na (MþNaþ)
618.3545; found 618.3548.
2.4.2. Compound 9e. (quant.); 1H NMR (400 MHz, D2O) d
5.35 (s, 1H), 5.15 (s, 1H), 4.15–2.85 (m, 30H), 2.42 (m,
1H), 1.90 (m, 3H); 13C NMR (75 MHz, D2O) d 165.8,
163.6, 115.3, 101.9, 94.1, 83.1, 82.3, 77.7, 74.4, 69.2, 67.1,
63.6, 55.1, 49.0, 47.9, 46.3, 38.9, 37.7, 32.2, 25.8; [a]D¼
þ29 (c 1.0, H2O).
2.4.7. Compound 12. A solution of 10 (50.0 mg,
0.037 mmol) in MeOH (2 mL) was treated with a catalytic
amount of NaOMe. The reaction mixture was stirred at
room temperature until completion (approximately 2 h),
neutralized by addition of Amberlite IR-120(Hþ), the resin
was filtered off and the filtrate was evaporated to dryness.
2.4.3. Compound 9g. (quant.); 1H NMR (400 MHz, D2O) d
5.27 (s, 1H), 5.05 (s, 1H), 4.50–3.05 (m, 30H), 2.40 (m,