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6 The β-stereochemistry of the major isomer was assigned by the NOE correlations of N-H proton of the indole with H(2) and H(4) of the flavan nucleus. On the other hand, the α-stereochemistry of the minor isomer was assigned by the NOE correlations between H(2) and H(4) of the flavan skeleton. The NOE correlations of the H(4) of the indole and the methylene protons of the indole side chain assured the connectivity as indicated, excluding the exchange of the C(2) and C(3) substituents (Figure 3). Compare: Jackson AH.
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10 Compound 13: colorless amorphous solids. 1H NMR (400 MHz, CDCl3): δ = -0.52 (s, 3 H), -0.20 (s, 3 H), -0.18 (s, 3 H), -0.10 (s, 3 H), 0.69 (s, 9 H), 0.85 (s, 9 H), 3.80 (dd, 1 H, J = 10.0, 2.4 Hz), 4.98 (s, 2 H), 5.01 (d, 1 H, J = 2.4 Hz), 5.02 (s, 2 H), 5.09 (s, 2 H), 5.33 (d, 1 H, J = 10.0 Hz), 6.19 (d, 1 H, J = 2.2 Hz), 6.21 (d, 1 H, J = 2.2 Hz), 6.95 (d, 2 H, J = 8.8 Hz), 7.28-7.44 (m, 17 H). 13C NMR (100 MHz, CDCl3): δ = -5.7, -5.3, -4.59, -4.58, 17.9, 18.4, 25.8, 26.0, 63.2, 70.0, 70.1, 70.2, 73.7, 76.1, 92.8, 94.1, 106.8, 114.6, 127.3, 127.6, 127.77, 127.82, 128.01, 128.04, 128.47, 128.52, 128.6, 129.2, 132.1, 136.6, 136.7, 137.1, 155.9, 157.2, 158.6, 160.5. IR (KBr): 3066, 3033, 2927, 2856, 1616, 1593, 1514, 1377, 1250, 1151, 1076, 883, 837, 775, 673 cm-1. Anal. Calcd for C48H60O6Si2: C, 73.05; H, 7.66. Found: C, 72.87; H, 7.86.
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16 Compound 21: colorless powders, mp 234-236 °C. 1H NMR (400 MHz, DMSO): δ = 2.81 (br t, 2 H, J = 7.3 Hz), 3.43 (br td, 2 H, J = 7.3, 5.6 Hz), 5.09 (s, 2 H), 5.13 (s, 2 H), 6.47 (d, 1 H, J = 16.1 Hz), 6.72 (dd, 1 H, J = 8.5, 2.2 Hz), 6.90 (br d, 1 H, J = 2.2 Hz), 7.00 (br s, 1 H), 7.03 (d, 2 H, J = 8.6 Hz), 7.27-7.52 (m, 14 H), 8.10 (br t, 1 H, J = 5.6 Hz), 10.6 (br s, 1 H). 13C NMR (100 MHz, DMSO): δ = 25.4, 39.6, 69.3, 69.5, 96.0, 109.1, 111.8, 115.2, 118.9, 120.0, 121.4, 121.9, 127.5, 127.6, 127.7, 127.9, 128.4, 128.5, 129.0, 136.8, 137.7, 138.1, 154.4, 159.3, 165.1. IR (KBr): 3224, 1645, 1601, 1539, 1510, 1452, 1174, 694 cm-1. Anal. Calcd for C33H30N2O3: C, 78.86; H, 6.02; N, 5.57. Found: C, 78.94; H, 5.91; N, 5.43.
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18 Compound 3: 1H NMR (500 MHz, CD3OD): δ = 2.98-3.10 (m, 2 H), 3.47-3.55 (m, 1 H), 3.69-3.77 (m, 1 H), 4.15 (dd, 1 H, J = 9.6, 5.7 Hz), 4.67 (d, 1 H, J = 5.7 Hz), 4.95 (d, 1 H, J = 9.6 Hz), 5.95 (d, 1 H, J = 2.4 Hz), 6.00 (d, 1 H, J = 2.4 Hz), 6.27 (d, 1 H, J = 15.7 Hz), 6.55 (dd, 1 H, J = 8.5, 2.2 Hz), 6.74 (d, 1 H, J = 2.2 Hz), 6.77 (d, 2 H, J = 8.7 Hz), 6.78 (d, 2 H, J = 8.7 Hz), 7.24 (d, 2 H, J = 8.7 Hz), 7.27 (d, 2 H, J = 8.7 Hz), 7.33 (d, 1 H, J = 8.5 Hz), 7.35 (d, 1 H, J = 15.7 Hz), 9.30 (br s, 1 H). 13C NMR (125 MHz, CD3OD): d = 25.3, 36.2, 41.3, 71.8, 79.6, 95.8, 96.8, 97.8, 102.9, 109.6, 111.7, 116.1, 116.7, 118.7, 119.4, 123.9, 127.9, 130.2, 130.6, 131.7, 133.9, 138.6, 141.5, 153.6, 157.5, 158.1, 158.5, 159.1, 160.4, 169.3. IR (KBr): 3300, 1647, 1514, 1458, 1227, 1146, 829 cm-1. Anal. Calcd for C34H30N2O8: C, 68.68; H, 5.09; N, 4.71. Found: C, 68.41; H, 5.38; N, 4.42.
19 Compound 24: 1H NMR (400 MHz, CD3OD): δ = 2.90-3.05 (m, 1 H), 3.05-3.20 (m, 1 H), 3.46-3.58 (m, 1 H), 3.64-3.78 (m, 1 H), 4.08 (dd, 1 H, J = 9.8, 8.8 Hz), 4.33 (d, 1 H, J = 8.8 Hz), 4.62 (d, 1 H, J = 9.8 Hz), 5.95 (d, 1 H, J = 2.4 Hz), 5.98 (d, 1 H, J = 2.4 Hz), 6.38 (d, 1 H, J = 15.9 Hz), 6.52 (dd, 1 H, J = 8.6, 2.4 Hz), 6.66 (d, 1 H, J = 2.4 Hz), 6.75 (d, 2 H, J = 8.6 Hz), 6.81 (d, 2 H, J = 8.8 Hz), 7.25 (d, 2 H, J = 8.6 Hz), 7.27 (d, 1 H, J = 8.6 Hz), 7.33 (d, 2 H, J = 8.8 Hz), 7.37 (d, 1 H, J = 15.9 Hz), 8.02 (br s, 1 H), 9.52 (br s, 1 H). 13C NMR (100 MHz, CD3OD): δ = 25.3, 41.3, 41.8, 75.1, 83.4, 96.6, 97.7, 97.9, 104.1, 109.3, 110.6, 116.1, 116.7, 118.8, 119.0, 123.6, 127.9, 130.3, 130.6, 131.0, 136.9, 138.6, 141.5, 153.5, 158.4, 158.6, 158.8, 159.0, 160.4, 169.3. IR (KBr): 3326, 1647, 1604, 1516, 1458, 1234, 1173, 1145, 1068, 831 cm-1. Anal. Calcd for C34H30N2O8: C, 68.68; H, 5.09; N, 4.71. Found: C, 68.43; H, 5.38; N, 4.46.
