Table 2.
1H NMR (300 MHz), 13C NMR (75 MHz), 1H—1H COSY, NOESY, and HMBC spectral data for corallolide B (2)a
| position | δH, mult, intgt (J, Hz) | δC (mult)b | 1H–1H COSY | NOESY | HMBCc |
|---|---|---|---|---|---|
| 1 | 2.74, br d, 1H (10.4) | 50.5 (CH) | H12β | H3, H4, H14αβ | H14αβ, H3-15 |
| 2 | 209.8 (C) | H1, H3 | |||
| 3 | 4.44, s, 1H | 73.1 (CH) | H1, H4, H9, H12α | H3-16 | |
| 4 | 1.78, br q (6.9) | 41.6 (CH) | H3-16 | H1, H3, H3-16 | H3, H3-16 |
| 5 | 84.3 (C) | H3, H3-16 | |||
| 6 | 208.1 (C) | H18α | |||
| 7 | 135.7 (C) | H18α, H3-19 | |||
| 8 | 5.89, br s, 1H | 76.1 (CH) | H9, H18αβ, H3-19 | H9 | H9 |
| 9 | 8.09, br s, 1H | 150.5 (CH) | H8 | H3, H8, H12αβ | |
| 10 | 133.6 (C) | H9, H11αβ | |||
| 11αβ | 2.42, br m, 2H | 20.8 (CH2) | H12αβ | H1, H12α | |
| 12αβ | 1.54, br m, 1H; 2.17, br m, 1H | 31.6 (CH2) | H1, H11αβ | H3, H9 | H1 |
| 13 | 138.2 (C) | H1, H3-15 | |||
| 14αβ | 5.08, br s, 1H; 4.80, br s, 1H | 115.3 (CH2) | H3-15 | H1, H3-15 | H1, H3-15 |
| 15 | 1.70, br s, 3H | 21.8 (CH3) | H14αβ | H14α | H1, H14αβ |
| 16 | 0.88, d, 3H (6.9) | 7.1 (CH3) | H4 | H4, H18α | H3, H4 |
| 17 | 169.1 (C) | H18α, H3-19 | |||
| 18αβ | 2.64, br d, 1H (17.3); 2.77, br d, 1H (17.3) | 44.3 (CH2) | H8 | H3-16 | H3-19 |
| 19 | 2.33, br s, 3H | 19.4 (CH3) | H8 | ||
| 20 | 174.0 (C)d | H9 |
a
Spectra were recorded in CDCl3 at 25 °C. Chemical shift values are in parts per million relative to the residual CHCl3 (7.26 ppm) or CDCl3 (77.0 ppm) signals. Assignments were aided by 2D NMR experiments, spin-splitting patterns, number of attached protons, and chemical shift values.
b
13C NMR multiplicities were obtained from a DEPT-135 experiment.
c
Protons correlated to carbon resonances in the 13C column. Parameters were optimized for 2,3JCH = 6 and 8 Hz.
d
Due to its low intensity the chemical shift value of this peak was carefully estimated from HMBC experiments.