Table 1.
1H and 13C-NMR spectral data of compound 1 (300/75 MHz, CDCl3, J in Hz)
| Position | Carbon | Proton | HMBC (→C) | ||
|---|---|---|---|---|---|
| δc[ppm] | δH[ppm] | Mult. | J [Hz] (→H) | ||
| 1 | 177.5 | ||||
| 2a + b | 29.1 | 2.528 | dd | 6.84 (3a), 9.51 (3b) | 1, 4 |
| 3a | 28.3 | 2.319 | ddt | 6.84 (2), −12.69 (3b), 6.62 (4) | 1, 4, 5 |
| b | 1.846 | ddt | 9.51 (2), −12.69 (3a), 5.60 (4) | 1, 4, 5 | |
| 4 | 81.2 | 4.484 | ddt | 6.62 (3a), 5.60 (3b), 6.84 (5a), 7.72 (5b) | 1, 5, 6 |
| 5a | 35.8 | 1.721 | dt | 6.84 (4), −11.98 (5b), 5.88 (6) | 6, 7 |
| b | 1.609 | ma | 6.00 (6), 7.72 (4), −11.98 (5a) | ||
| 6a + b | 25.1 | 1.408 | ma | 6.00 (5b), 5.88 (5a), 5.56 (7) | 7, 8 |
| 7a + b | 29.6 | 1.408 | ma | 5.56 (6), 5.50 (8), 0.45 (9)b | 6, 9 |
| 8a + b | 27.2 | 2.039 | dt | 5.50 (7), 6.81 (9) | 6, 10 |
| 9 | 130.7 | 5.372 | dtt | 0.45 (7)b, 6.81 (8), 10.94 (10) | 7, 11 |
| 10 | 129.4 | 5.328 | dtt | 10.94 (9), 6.71 (11), 0.49 (12)b | 8, 12 |
| 11a + b | 27.5 | 2.014 | dt | 6.71 (10) | 9 |
| 12a + b | 29.7 | 1.269 | ma | 0.49 (10)b | |
| 13a + b | 29.8 | 1.269 | ma | ||
| 14a + b | 29.9 | 1.269 | ma | ||
| 15a + b | 30.0 | 1.269 | ma | ||
| 16a + b | 32.2 | 1.269 | ma | 18 | |
| 17a + b | 22.9 | 1.269 | ma | 18 | |
| 18 | 14.4 | 0.881 | br t/m | 6.78 (17) | 16, 17 |
a
Overlapping peaks limited effective iteration, resulting in unresolved exact resonances and J values (see text).
b
An interesting observation is that, instead of the expected allylic4J9, 11 and 4J8, 10 couplings, W-type 4J7, 9 and 4J10, 12 long-range couplings are observed.