HETEROCYCLES, Vol. 83, No. 3, 2011
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(2C, d), 121.95 (d), 120.23 (d), 111.32 (d), 110.59 (d), 79.42 (s), 73.16 (t), 69.38 (t), 55.72 (2C, q), 53.93
(d), 51.22 (q), 50.90 (d), 28.10 (3C, q); IR (ATR) cm-1: 3366, 1707, 1653; FAB-MS (pos) m/z: 486
[M+1]+, 430, 386; HRMS (FAB-pos) m/z calcd for C27H36NO7 486.2492 found 486.2517.
(2E,4RS,5SR)-6-Benzyloxy-5-benzyloxycarbonylamino-4-(3’,4’-dimethoxyphenyl)hex-2-enoic acid
1
methyl ester (40a): Colorless oil; H-NMR (CDCl3) : 7.39-7.22 (10H, m), 7.18 (1H, dd, J = 15.6, 8.8
Hz), 6.79 (1H, d, J = 8.4 Hz), 6.74 (1H, d, J = 8.4 Hz), 6.71 (1H, s), 5.82 (1H, d, J = 15.6 Hz), 5.26 (1H, d,
J = 9.6 Hz), 5.14 (1H, d, J = 12.4 Hz), 5.08 (1H, d, J = 12.4 Hz), 4.40 (1H, d, J = 11.8 Hz), 4.31 (1H, d, J
= 11.8 Hz), 4.16 (1H, m), 3.86 (3H, s), 3.82 (3H, s), 3.69 (1H, t, J = 9.6 Hz), 3.68 (3H, s), 3.40 (1H, dd, J
13
= 9.6, 3.2 Hz), 3.23 (1H, dd, J = 9.6, 2.8 Hz); C-NMR (CDCl3) : 166.53 (s), 156.01 (s), 149.15 (s),
148.56 (d), 148.10 (s), 137.63 (s), 136.37 (s), 131.71 (s), 128.46 (2C, d), 128.34 (2C, d), 128.03 (d),
127.92 (2C, d), 127.74 (d), 127.54 (2C, d), 122.35 (d), 120.30 (d), 111.36 (d), 110.78 (d), 73.22 (t), 69.34
(t), 66.75 (t), 55.80 (2C, q), 54.51 (d), 51.43 (q), 50.35 (d); IR (ATR) cm-1: 3342, 1718, 1654; FAB-MS
(pos) m/z: 520 [M+1]+, 476; HRMS (FAB-pos) m/z calcd for C30H34NO7 520.2335 found 520.2341.
(2E,4RS,5SR)-6-Benzyloxy-5-benzyloxycarbonylamino-4-(2’,4’-dimethoxyphenyl)hex-2-enoic acid
methyl ester (41a): Colorless oil; 1H-NMR (CDCl3) : 7.42-7.20 (11H, m), 7.04 (1H, d, J = 8.0 Hz), 6.43
(1H, s), 6.42 (1H, d, J = 7.6 Hz), 5.78 (1H, d, J = 15.6 Hz), 5.22 (1H, d, J = 9.6 Hz), 5.12 (1H, d, J = 12.4
Hz), 5.07 (1H, d, J = 12.4 Hz), 4.43 (1H, m), 4.37 (1H, d, J = 11.8 Hz), 4.28 (1H, d, J = 11.8 Hz), 3.98
(1H, t, J = 9.6 Hz), 3.78 (3H, s), 3.77 (3H, s), 3.66 (3H, s), 3.42 (1H, dd, J = 9.6, 3.2 Hz), 3.24 (1H, dd, J
= 9.6, 2.4 Hz); 13C-NMR (CDCl3) : 166.82 (s), 160.01 (s), 158.01 (s), 156.04 (s), 148.78 (d), 137.92 (s),
136.55 (s), 130.12 (d), 128.42 (3C, d), 128.24 (2C, d), 127.93 (d), 127.87 (d), 127.54 (d), 127.46 (2C, d),
121.92 (d), 119.73 (s), 104.47 (d), 98.85 (d), 73.12 (t), 69.82 (t), 66.58 (t), 55.26 (2C, q), 52.98 (d), 51.30
(q), 45.70 (d); IR (ATR) cm-1: 3342, 1718, 1654; FAB-MS (pos) m/z: 520 [M+1]+, 476, 444; HRMS
(FAB-pos) m/z calcd for C30H34NO7 520.2335 found 520.2314.
(2E,4R,5S)-5-tert-Butoxycarbonylamino-6-tert-butyldimethylsilyloxy-4-(2’-methoxy-5’-methylphenyl)-
hex-2-enoic acid methyl ester (42a): Colorless oil; 1H-NMR (CDCl3) : 7.25 (1H, dd, J = 15.6, 9.2 Hz),
7.05-6.96 (2H, m), 6.74 (1H, d, J = 8.4 Hz), 5.77 (1H, d, J = 15.6 Hz), 4.89 (1H, d, J = 9.6 Hz), 4.27 (1H,
br t, J = 10.0 Hz), 3.93 (1H, t, J = 9.6 Hz), 3.77 (3H, s), 3.66 (3H, s), 3.51 (1H, dd, J = 10.0, 3.2 Hz), 3.32
(1H, dd, J = 10.0, 2.0 Hz), 2.24 (3H, s), 1.42 (9H, s), 0.88 (9H, s), -0.06 (3H, s), -0.10 (3H, s); 13C-NMR
(CDCl3) : 166.94 (s), 155.63 (s), 155.02 (s), 149.40 (d), 130.40 (d), 129.90 (s), 128.51 (d), 127.25 (s),
121.77 (d), 110.76 (d), 79.26 (s), 62.66 (t), 55.34 (q), 53.56 (d), 51.24 (q), 45.87 (d), 28.29 (3C, q), 25.78
(3C, q), 20.38 (q), 18.22 (s), -5.79 (q), -5.84 (q); IR (film) cm-1: 3451, 3370, 1723, 1651; EI-MS m/z: 493
27
[M]+; HR-MS m/z: calcd for C26H44NO6Si [M+1]+ 494.2938 found 444.2918; []D −47.53 (CDCl3, c
1.04).