J. C. Anderson et al. / Tetrahedron: Asymmetry 9 (1998) 3461–3490
3477
C13H17O3N requires C, 66.35; H, 7.29; N, 5.96%); [α]D22=−82.5 (c 2, CHCl3); νmax (film)/cm−1 2966,
1743 (C_O), 1682 (HC_O), 1596, 1496; δH (250 MHz; CDCl3) 0.91 (3H, d, J 6.6, CH(CH3)2), 0.99
(3H, d, J 6.6, CH(CH3)2), 2.36 (1H, dsept, J 10.1, 6.6, CH(CH3)2), 3.54 (3H, s, CO2CH3), 4.64 (1H, d,
J 10.1, CHCO2Me), 7.24–7.43 (5H, m, Ar), 6.35 (1H, s, CHO); δC (63 MHz; CDCl3) 19.8 (CH(CH3)2),
20.3 (CH(CH3)2), 27.8 (CH(CH3)2), 52.1 (CO2CH3), 63.8 (CHCH(CH3)2), 126.4 (Ar), 127.7 (Ar), 129.5
(Ar), 39.7 (Ar), 163.2 (HC_O), 170.9 (C_O); m/z (EI) 235 (M+, 13%), 206 (100), 120 (12), 115 (26),
77 (14). (Found: M+, 235.1210. C13H17NO3 requires M, 235.1208.)
6.10. (S)-N-Methyl-N-phenyl-2-amino-3-methylbutan-1-ol 14
A solution of 13 (1.29 g, 5.5mmol) in tetrahydrofuran (20 ml) was added to a suspension of lithium
aluminium hydride (1.05 g, 27.5 mmol) in diethyl ether (20 ml) at 0°C under nitrogen. The suspension
was stirred for a further 15 minutes and then quenched at 0°C by careful addition of water (1 ml), aqueous
sodium hydroxide (15% w/v, 1 ml) and water (3 ml). The resulting white suspension was filtered through
a pad of Celite™ꢀ and the residue washed with tetrahydrofuran (25 ml). The organic layers were dried
(MgSO4) and concentrated in vacuo to yield a white solid which was recrystallised to afford 14 (1.04
g, 98%) as a white solid, mp 78–79°C (light petroleum) (found: C, 74.42; H, 9.94; N, 7.11; C12H19ON
requires C, 74.55; H, 9.91; N, 7.25%); [α]D22=−153.8 (c 1.3, CHCl3); νmax (film)/cm−1 3323 (OH),
2960, 2896, 2802, 1600, 1570; δH (250 MHz; CDCl3) 0.76 (3H, d, J 6.7, CH(CH3)2), 0.93 (3H, d, J 6.7,
CH(CH3)2), 1.75–1.97 (1H, m, CH(CH3)2), 2.05 (1H, brs, CH2OH), 2.78 (3H, s, NCH3), 3.52–3.19 (2H,
m, CH2OH), 3.76–3.91 (1H, br m, CHCH(CH3)2), 6.71–7.32 (5H, m, Ar); δC (63 MHz; CDCl3) 20.0
(CH(CH3)2), 20.89 (CH(CH3)2), 29.04 (CH(CH3)2), 30.1 (NCH3), 61.0 (CH2OH), 67.7 (CHCH(CH3)2),
113.7 (Ar), 117.4 (Ar), 129.2 (Ar), 152.2; m/z (EI) 193 (M+, 20%), 162 (100), 150 (45). (Found: M+,
193.1463. C12H19NO requires M, 193.1466.)
6.11. (S)-N-Methyl-N-phenyl-2-amino-3-methyl-1-thiolacetyl butane
Identical to the preparation of 12, gave the N-methyl,N-phenyl thioacetate (83%) as a colourless oil
(found: C, 67.06; H, 8.59; N, 5.52; S, 12.66; C14H21ONS requires C, 66.89; H, 8.42; N, 5.52; S, 12.75%);
[α]D22=+9.0 (c 1.2, CHCl3); νmax (film)/cm−1 2924, 1689 (C_O), 1598, 1504; δH (250 MHz; CDCl3)
0.82 (3H, d, J 6.6, CH(CH3)2), 1.07 (3H, d, J 6.6, CH(CH3)2), 1.81–2.02 (1H, m, CH(CH3)2), 2.22
(3H, s, SCOCH3), 2.71 (3H, s, NCH3), 2.98 (1H, dd, J 13.7, 11.0, CHCHαHβ), 3.49 (1H, dd, J 13.7,
3.7, CHCHαHβ), 3.64 (1H, ddd, J 11.0, 9.7, 3.7, CHCH(CH3)2), 6.62–7.25 (5H, m, Ar); δC (63 MHz;
CDCl3) 20.4 (CH(CH3)2), 20.7 (CH(CH3)2), 30.6 (CH(CH3)2), 31.3 (CH2S), 32.0 (CHCH(CH3)2), 30.1
(SCOCH3), 63.5 (NCH3), 112.5 (Ar), 116.3 (Ar), 129.0 (Ar), 152.2 (C_O); m/z (EI) 251 (M+, 32%),
208 (69), 166 (32), 162 (100), 77 (34). (Found: M+, 251.1351. C14H21NOS requires M, 251.1344.)
6.12. (S)-N-Methyl-N-phenyl-2-amino-3-methylbutan-1-thiol 2
Identical to the preparation of 1, gave 2 (98%) as a colourless oil; [α]D22=−93.8 (c 0.8, CHCl3); νmax
(film)/cm−1 2959, 2566w (SH), 1598, 1504; δH (250 MHz; CDCl3) 0.73 (3H, d, J 6.6, CH(CH3)2), 0.92
(3H, d, J 6.6, CH(CH3)2), 1.38 (1H, dd, J 8.6, 5.5, SH), 1.8 (1H, dsept, J 9.5, 6.6, CH(CH3)2), 2.67
(3H, s, NCH3), 2.68–2.80 (2H, m, CH2SH), 3.52 (1H, dt, J 9.5, 4.9, CHCH(CH3)2), 6.57–7.19 (5H, m,
Ar); δC (63 MHz; CDCl3) 20.5 (CH(CH3)2), 20.9 (CH(CH3)2), 26.3 (CH2SH), 30.2 (CH(CH3)2), 31.8
(NCH3), 67.3 (CHCH(CH3)2), 112.7 (Ar), 116.5 (Ar), 129.3 (Ar), 151.1; m/z (CI) 209 (M+, 33%), 166
(64), 162 (100), 132 (16), 107 (12), 86 (10). (Found: M+, 209.1244. C12H19NS requires M, 209.1238.)