Table 1.
The NMR data of compound 1a.
| Position | 1H-NMR | 13C-NMR | HMBC (H→C) |
|---|---|---|---|
| 1 | 1.88 (1H, m) | 38.6 | C-3, 7, 9, 12, 13 |
| 2a | 2.86 (1H, dd, 12.6, 1.8) | 47.9 | C-1, 3, 10 |
| 2b | 2.34 (1H, ddd, 12.6, 7.8, 1.2) | C-1, 3, 4, 10, 11 | |
| 3 | - | 211.3 | |
| 4a | 2.88 (1H, ddd, 13.2,7.8, 1.8) | 52.6 | C-2, 3, 5, 6 |
| 4b | 2.62 (1H, dd, 13.2, 3.0) | C-3, 5, 6 | |
| 5 | 4.39 (1H, ddt, 10.2, 7.2, 1.8) | 72.2 | C-3, 7, 8 |
| 6a | 2.64 (1H, dd, 14.4, 10.2) | 35.4 | C-4, 5, 7, 11 |
| 6b | 2.18 (1H, br d, 14.4) | C-4, 7, 8, 11 | |
| 7 | 1.77 (1H, d, 10.2) | 50.6 | C-1, 5, 12, 14 |
| 8 | - | 83.8 | |
| 9a | 1.85 (1H, m) | 30.3 | C-1, 7, 8, 10 |
| 9b | 1.79 (1H, m) | C-8, 10 | |
| 10a | 1.94 (1H, m) | 19.6 | C-1, 2, 8, 9 |
| 10b | 1.90 (1H, m) | C-1, 2, 8, 9 | |
| 11 | - | 35.1 | |
| 12 | 1.14 (3H, s) | 34.3 | C-1, 7, 11, 13 |
| 13 | 1.11 (3H, s) | 28.4 | C-1, 7, 11, 12 |
| 14 | 1.17 (3H, s) | 30.1 | C-7, 8, 9 |
a 1H-NMR (600 MHz), 13C-NMR (150 MHz) spectra of compound 1 were measured in CDCl3 on a Varian Inova-600 MHz spectrometer, δ in ppm, J in Hz.