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J ¼ 6.6 Hz), 1.09 (3H, d, J ¼ 6.0 Hz), 1.21–1.44 (10H, m),
1.72 (1H, m), 2.32 (1H, dt, J ¼ 9.3, 5.4 Hz), 3.44 (2H, d,
J ¼ 13.3 Hz), 3.60 (1H, m), 3.85 (2H, d, J ¼ 13.3 Hz),
4.34 (1H, br), 7.21–7.33 (10H, m). MS m=z 340 [M+1]þ.
Anal. Calcd for C23H33NO: C, 81.73; H, 9.80; N, 4.13.
Found: C, 81.58; H, 9.90; N, 4.37.
for C23H33NOÆ0.2H2O: C, 80.51; H, 9.81; N, 4.08.
Found: C, 80.76; H, 9.80; N, 4.23.
5.4.12. ( )-N,N-Dibenzyl-3-aminodecan-2-ol [( )-10g].
Yield 71%. 1H NMR (CDCl3) d: 0.90 (3H, t,
J ¼ 6.8 Hz), 1.18 (3H, d, J ¼ 6.6 Hz), 1.20–1.48 (11H, m),
1.70 (1H, m), 2.32 (1H, br), 2.64 (1H, m), 3.62 (2H, d,
J ¼ 13.7 Hz), 3.73 (2H, d, J ¼ 13.5 Hz), 3.89 (1H, m),
7.20–7.34 (10H, m). MS m=z 354 [M+1]þ. Anal. Calcd
for C24H35NO: C, 81.53; H, 9.98; N, 3.96. Found: C,
81.28; H, 9.86; N, 4.10.
5.4.6. ( )-N,N-Dibenzyl-3-aminodecan-2-ol [( )-5g].
Yield 40%. 1H NMR (CDCl3) d: 0.92 (3H, t,
J ¼ 6.7 Hz), 1.09 (3H, d, J ¼ 6.0 Hz), 1.21–1.44 (11H, m),
1.72 (1H, m), 2.32 (1H, dt, J ¼ 9.3, 5.4 Hz), 3.44 (2H, d,
J ¼ 13.4 Hz), 3.60 (1H, m), 3.85 (2H, d, J ¼ 13.2 Hz),
4.34 (1H, s), 7.21–7.33 (10H, m). MS m=z 354 [M+1]þ.
Anal. Calcd for C24H35NOÆ0.1H2O: C, 81.12; H, 9.98;
N, 3.94. Found: C, 81.22; H, 10.04; N, 4.08.
5.5. Synthesis of ( )-2-aminopentan-3-ol [( )-6a]
To a solution of ( )-5a (5.89 g, 20.8 mmol) in MeOH
(400 mL) was added 20% Pd(OH)2–C (1.47 g) in one
portion under argon. The mixture was stirred under
1 atm of hydrogen over night, and the catalyst was re-
moved by filtration through Celite and washed with
MeOH. The combined filtrate was evaporated under
reduced pressure to afford the title compound ( )-6a
(2.00 g, 93%). 1H NMR (CDCl3) d: 0.99 (3H, t,
J ¼ 7.4 Hz), 1.10 (3H, d, J ¼ 6.4 Hz), 1.37 (1H, m), 1.55
(1H, m), 1.90–2.10 (2H, br), 2.75 (1H, qu, J ¼ 6.4 Hz),
3.12 (1H, dq, J ¼ 3.7, 3.4 Hz). MS m=z 104 [M+1]þ. The
title compound was treated with oxalic acid in EtOH/n-
hexane solution to give the oxalate as a white solid, mp
104–105 ꢁC. Anal. Calcd for C5H13NOÆC2H2O4: C,
43.52; H, 7.83; N, 7.25. Found: C, 43.63; H, 7.82; N,
7.32.
5.4.7. ( )-N,N-Dibenzyl-3-aminopentan-2-ol [( )-10b].
Yield 77%. 1H NMR (CDCl3) d: 1.00 (3H, t,
J ¼ 7.5 Hz), 1.19 (3H, d, J ¼ 6.6 Hz), 1.50 (1H, m), 1.77
(1H, m), 2.58 (1H, td, J ¼ 7.0, 4.7 Hz), 3.64 (2H, d,
J ¼ 13.5 Hz), 3.74 (2H, d, J ¼ 13.7 Hz), 3.90 (1H, m). MS
m=z 284 [M+1]þ. Anal. Calcd for C19H25NOÆ0.4H2O: C,
78.52; H, 8.95; N, 4.82. Found: C, 78.70; H, 8.76; N,
4.92.
5.4.8. ( )-N,N-Dibenzyl-4-aminohexan-3-ol [( )-10c].
Yield 68%. 1H NMR (CDCl3) d: 0.89 (3H, t,
J ¼ 7.3 Hz), 0.99 (3H, d, J ¼ 7.3 Hz), 1.27–1.84 (4H, m),
2.58 (1H, td, J ¼ 7.0, 4.1 Hz), 3.60 (1H, m), 3.68 (4H, s),
7.20–7.39 (10H, m). MS m=z 298 [M+1]þ. Anal. Calcd
for C20H27NOÆ0.1H2O: C, 80.28; H, 9.16; N, 4.68.
Found: C, 80.33; H, 9.21; N, 4.95.
The following amino alcohol derivatives were synthe-
sized according to a synthetic method similar to that of
( )-6a.
5.4.9. ( )-N,N-Dibenzyl-3-aminohexan-2-ol [( )-10d].
Yield 65%. 1H NMR (CDCl3) d: 0.91 (3H, t,
J ¼ 6.9 Hz), 1.18 (3H, d, J ¼ 6.6 Hz), 1.35–1.72 (4H, m),
2.30 (1H, br), 2.65 (1H, td, J ¼ 6.3, 4.8 Hz), 3.62 (2H, d,
J ¼ 13.6 Hz), 3.73 (2H, d, J ¼ 13.7 Hz), 3.89 (1H, m),
7.20–7.35 (10H, m). MS m=z 298 [M+1]þ. Anal. Calcd
for C20H27NO: C, 80.76; H, 9.15; N, 4.71. Found: C,
81.01; H, 8.91; N, 5.07.
5.5.1. ( )-3-Aminopentan-2-ol [( )-6b]. Yield 67%. Mp
1
28–30 ꢁC (hexane). H NMR (CDCl3) d: 0.98 (3H, t,
J ¼ 7.4 Hz), 1.19 (3H, d, J ¼ 6.0 Hz), 1.26 (1H, m), 1.62
(1H, m), 2.15–2.35 (3H, br), 2.42 (1H, m), 3.46 (1H, qu,
J ¼ 6.3 Hz). MS m=z 104 [M+1]þ. Anal. Calcd for
C21H29NOÆ0.1H2O: C, 57.21; H, 12.68; N, 13.34. Found:
C, 57.15; H, 12.50; N, 13.15.
5.5.2. ( )-4-Aminohexan-3-ol [( )-6c]. Yield 84%. Mp
1
5.4.10. ( )-N,N-Dibenzyl-3-aminoheptan-2-ol [( )-10e].
Yield 73%. 1H NMR (CDCl3) d: 0.92 (3H, t, J ¼ 7.1 Hz),
1.17 (3H, d, J ¼ 6.6 Hz), 1.23–1.50 (6H, m), 2.33 (1H,
br), 2.64 (1H, m), 3.62 (2H, J ¼ 13.5 Hz), 3.74 (2H,
J ¼ 13.5 Hz), 3.89 (1H, m), 7.20–7.34 (10H, m). MS m=z
312 [M+1]þ. Anal. Calcd for C21H29NO: C, 80.98; H,
9.38; N, 4.50. Found: C, 80.87; H, 9.29; N, 4.58.
43–44 ꢁC (hexane). H NMR (CDCl3) d: 0.99 (3H, t,
J ¼ 7.4 Hz), 1.10 (3H, d, J ¼ 6.4 Hz), 1.39 (1H, m), 1.55
(1H, m), 1.85 (3H, br), 2.75 (1H, qu, J ¼ 6.4 Hz), 3.11
(1H, m). MS m=z 118 [M+1]þ. Anal. Calcd for
C6H15NO: C, 61.49; H, 12.90; N, 11.95. Found: C,
61.25; H, 12.65; N, 11.71.
5.4.11. ( )-N,N-Dibenzyl-3-aminononan-2-ol [( )-10f].
Yield 78%. 1H NMR (CDCl3) d: 0.90 (3H, t,
J ¼ 6.7 Hz), 1.18 (3H, d, J ¼ 6.6 Hz), 1.25–1.48 (9H, m),
1.70 (1H, m), 2.33 (1H, m), 2.64 (1H, m), 3.62 (2H, d,
J ¼ 13.7 Hz), 3.73 (2H, d, J ¼ 13.6 Hz), 3.90 (1H, m),
7.21–7.33 (10H, m). MS m=z 340 [M+1]þ. Anal. Calcd
5.5.3. ( )-3-Aminohexan-2-ol [( )-6d]. Yield 95%. 1H
NMR (CDCl3) d: 0.95 (3H, t, J ¼ 6.8 Hz), 1.22 (3H, d,
J ¼ 6.0 Hz), 1.31–1.56 (4H, m), 2.67 (1H, td, J ¼ 7.9,
3.0 Hz), 3.55 (1H, m), 3.35–3.70 (3H, br). MS m=z 118
[M+1]þ. Anal. Calcd for C6H15NO: C, 61.49; H, 12.90;
N, 11.95. Found: C, 61.38; H, 12.42; N, 11.76.