Table 1.
1H and 13C NMR chemical shifts of madagascarensilides A (1), B (2), C (3) and D (4)a
| position | 1b | 1c | 2b | 3c | 3b | 4b | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1H (J, Hz) | 13C | 1H (J, Hz) | 13C | 1H (J, Hz) | 13C | 1H (J, Hz) | 13C | 1H (J, Hz) | 13C | 1H (J, Hz) | 13C | |
| Aglycone | ||||||||||||
| 1 | 1.46 m | 31.0 | 30.9 | 31.0 | 2.59m, 1.91m | 18.9 | 1.72 m, 1.60m | 18.9 | 18.9 | |||
| 2 | 1.63 m | 27.5 | 27.5 | 28.1 | 2.19m, 1.68m | 26.0 | 1.94m, 1.61m | 25.9 | 25.9 | |||
| 3 | 4.02 m | 74.5 | 4.27 m | 73.6 | 4.26 m | 74.5 | 4.33 m | 75.3 | 4.15 m | 76.3 | 4.15 m | 76.3 |
| 4 | 1.83 m, 1.46 m | 31.4 | 31.2 | 31.4 | 2.19m, 1.73m | 36.2 | 2.17m, 1.62m | 36.8 | 36.8 | |||
| 5 | 1.66 m | 38.0 | 37.4 | 38.0 | OH 4.89s | 74.1 | 75.2 | 75.2 | ||||
| 6 | 1.88 m, 1.26 m | 27.9 | 27.5 | 27.5 | 2.34m, 1.82m | 37.3 | 2.17m, 1.62m | 37.2 | 37.2 | |||
| 7 | 1.78 m, 1.25 m | 22.4 | 22.0 | 22.4 | 2.33 m, 1.46m | 25.2 | 2.12m, 1.32m | 25.2 | 25.2 | |||
| 8 | 1.63 m | 42.7 | 42.3 | 42.7 | 2.31 m | 42.3 | 1.94 m | 42.6 | 42.6 | |||
| 9 | 1.73 m | 36.9 | 36.3 | 36.9 | 1.78m | 39.9 | 1.66m | 40.4 | 40.4 | |||
| 10 | 36.3 | 35.9 | 36.3 | 56.1 | 56.1 | 56.1 | ||||||
| 11 | 1.43 m, 1.24 m | 22.6 | 22.4 | 22.6 | 1.59m, 1.40m | 23.0 | 1.56m, 1.51m | 23.3 | 23.3 | |||
| 12 | 1.51 m | 41.0 | 40.3 | 41.0 | 1.45 m, 1.35m | 39.9 | 1.49 m, 143m | 40.5 | 40.5 | |||
| 13 | 51.1 | 50.5 | 51.1 | 50.2 | 50.7 | 50.7 | ||||||
| 14 | 86.5 | 85.0 | 86.5 | −OH, 5.66 | 84.8 | 85.9 | 85.9 | |||||
| 15 | 2.18, 1.73 | 33.4 | 33.6 | 33.4 | 2.08m, 1.86m | 32.5 | 2.17 m, 1.72 m | 32.4 | 32.4 | |||
| 16 | 2.18, 1.88 | 28.1 | 27.7 | 27.9 | 2.10m, 2.02m | 27.6 | 2.19 m, 2.14 m | 27.9 | 27.9 | |||
| 17 | 2.83 m | 52.1 | 2.79 m | 51.9 | 2.83 m | 52.1 | 2.79 m | 51.5 | 2.82 m | 51.7 | 2.82 m | 51.8 |
| 18 | 0.88 s | 16.4 | 0.89 s | 16.6 | 0.88 s | 16.4 | 1.01 | 16.4 | 0.85 s | 16.2 | 0.85 s | 16.2 |
| 19 | 0.94 s | 24.3 | 1.02 s | 24.3 | 0.95 s | 24.3 | 10.42 | 208.9 | 10.05 s | 209.9 | 10.05 s | 209.9 |
| 20 | 178.5 | 176.4 | 178.5 | 176.1 | 178.2 | 178.2 | ||||||
| 21 | 5.04 dd (18.6, 1.8) | 75.4 | 5.34 dd (18.2, 1.4) | 74.1 | 5.03 dd (18.4, 1.5) | 75.4 | 5.31 dd (18.2, 1.7) | 74.4 | 5.03 dd (18.5, 1.7) | 75.3 | 5.03 dd (18.5, 1.7) | 75.3 |
| 4.92 dd (18.6,1.8) | 5.06 dd (18.2,1.4) | 4.92 dd (18.4,1.5) | 5.05 dd (18.2, 1.7) | 4.91dd (18.5, 1.7) | 4.91dd (18.5, 1.7) | |||||||
| 22 | 5.90 s | 117.8 | 6.15 s | 118.1 | 5.90 s | 117.8 | 6.14 | 118.2 | 5.90 | 117.9 | 5.90 | 117.9 |
| 23 | 177.3 | 174.9 | 177.3 | 174.9 | 177.2 | 177.2 | ||||||
| Sugar I | ||||||||||||
| 1′ | 4.91 dd (9.5, 1.8) | 96.8 | 5.44 dd (9.5, 1.8) | 96.9 | 4.91 dd (9.4, 1.5) | 96.8 | 5.39 dd (9.6, 1.9) | 98.0 | 4.91 dd (8.9, 1.9) | 98.3 | 4.91 dd (8.9, 1.9) | 98.3 |
| 2′ | 1.95 m, 1.73 m | 39.0 | 2.43 m, 2.11 m | 39.9 | 1.95 m, 1.73 m | 38.9 | 2.34 m, 1.93 m | 39.1 | 1.98 m, 1.71 m | 38.7 | 1.98 m, 1.71 m | 38.7 |
| 3′ | 4.24 m | 68.7 | 4.71 m | 68.1 | 4.26 m | 68.7 | 4.61 m -OH, 5.52 |
67.8 | 4.24 m | 68.3 | 4.24 m | 68.3 |
| 4′ | 3.23 m | 84.3 | 3.67 dd (9.7, 2.7) | 84.7 | 3.23 dd (9.5, 2.9) | 84.1 | 3.50 dd (9.7, 3.0) | 83.2 | 3.23 dd (9.5, 2.9) | 83.5 | 3.23 m | 83.5 |
| 5′ | 3.85 m | 69.7 | 4.37 m | 69.3 | 3.85 m | 69.7 | 4.26 m | 69.2 | 3.80 m | 69.6 | 3.80 m | 69.6 |
| 6′ | 1.31 d (6.5) | 18.6 | 1.67 d (6.2). | 19.2 | 1.29 d (6.2) | 18.5 | 1.41d (6.3) | 18.9 | 1.21 d (6.2) | 18.4 | 1.21 d (6.1) | 18.4 |
| Sugar II | ||||||||||||
| 1″ | 4.37 d (7.7) | 106.2 | 4.77 d (7.7) | 106.7 | 4.34 (7.7) | 106.2 | 5.17 dd (9.7, 1.8) | 100.1 | 4.84 m | 100.7 | 4.84 m | 100.6 |
| 2″ | 3.66 m | 71.4 | 4.42 m | 71.7 | 3.55 dd (9.7, 7.7) | 71.4 | 2.28 m, 1.76m | 36.9 | 2.15 m, 1.62 m | 36.2 | 2.15 m, 1.62 m | 35.8 |
| 3″ | 3.25 m | 85.3 | 3.57 dd (9.7, 2.9) | 85.6 | 3.12 dd (9.7, 3.1) | 84.4 | 4.07 m | 78.1 | 3.87 m | 78.5 | 3.87 m | 78.2 |
| 4″ | 4.16 m | 76.3 | 4.28 m | 77.8 | 3.85 m | 68.6 | 3.48 dd (9.7, 2.7) | 83.3 | 3.30 m | 83.5 | 3.30 m | 83.7 |
| 5″ | 3.66 m | 71.8 | 3.75 m | 71.0 | 3.63 bq (6.4) | 71.6 | 4.20 m | 69.5 | 3.86 m | 70.1 | 3.86 m | 70.0 |
| 6″ | 1.29 d (6.5) | 17.4 | 1.55 d (6.4) | 17.9 | 1.27 d (6.4) | 17.0 | 1.34 d (6.3) | 18.9 | 1.22 d (6.2) | 18.6 | 1.22 d (6.2) | 18.6 |
| Sugar III | ||||||||||||
| 1‴ | 4.57 d (7.7) | 103.9 | 5.10 d (7.8) | 106.4 | 4.69 dd (9.7, 2.1) | 103.1 | 4.55 dd (9.7, 2.0) | 103.4 | 4.57 dd (9.7, 1.9) | 103.4 | ||
| 2‴ | 3.22 m | 76.0 | 4.02 t (7.8) | 76.6 | 2.17 m, 2.29 m | 33.1 | 1.93 m, 1.65 m | 32.9 | 2.00 m, 1.81m | 33.2 | ||
| 3‴ | 3.37 m | 78.2 | 4.26 m | 79.1 | 3.41 ddd (12.1, 4.7, 2.9) | 79.3 | 3.35 m | 79.2 | 3.47 m | 80.6 | ||
| 4‴ | 3.26 m | 71.8 | 4.25 m | 72.2 | 3.91 m -OH 6.00 |
67.1 | 3.67 m | 67.7 | 3.99 m | 74.6 | ||
| 5‴ | 3.26 m | 78.0 | 3.98 m | 78.9 | 3.56 qd (6.4, 1.3) | 71.9 | 3.49 qd (6.6, 1.3) | 72.0 | 3.53 m | 71.8 | ||
| 6‴ | 3.88 m, 3.65 m | 63.0 | 4.59 m, 4.38 m | 63.4 | 1.55 d (6.4) | 17.9 | 1.28 d (6.6) | 17.2 | 1.30 d (6.4) | 17.7 | ||
| Sugar IV | ||||||||||||
| 1″″ | 4.56 d (7.7) | 104.6 | ||||||||||
| 2″″ | 3.22 m | 76.0 | ||||||||||
| 3″″ | 3.36 m | 78.2 | ||||||||||
| 4″″ | 3.27 m | 71.8 | ||||||||||
| 5″″ | 3.25 m | 78.0 | ||||||||||
| 6″″ | 3.86m, 3.64m | 63.0 | ||||||||||
| 3″-OCH3 | 3.52 s | 58.8 | 3.69 s | 59.5 | 3.46 | 57.3 | 3.51 s | 59.1 | 3.44 s | 58.4 | 3.42 s | 58.0 |
| 3‴-OCH3 | 3.40 s | 55.7 | 3.38 s | 55.8 | 3.41 s | 56.6 | ||||||
a
δ (ppm) 500 MHz for 1H and 125 MHz for 13C; multiplicities; J values (Hz) in parentheses.
b
In CD3OD
c
In deuterated pyridine