Table 1.
Assignment of the 1 H- 1 H correlation signals found in the two-dimension COSY spectra of the transformed production
| Chemical shift (ppm) | J (Hz) | Number of proton | Assignment a | 1 H- 1 H COSY |
|---|---|---|---|---|
| 7.46 | d/5.0 | 1 | 10-OH (B) | H10 (B) |
| 6.82 | d/5.2 | 0.15 | 10-OH (A) | H10 (A) |
| 6.47 | s | 1 | 3-OH (B) | |
| 6.38 | s | 0.15 | 3-OH (A) | |
| 6.07 | s | 1 | H12 (B) | |
| 6.02 | s | 0.15 | H12 (A) | |
| 5.30 | d/4.0 | 1 | H6 (B) | H7a, H7b (B) |
| 5.02 | d/5.0 | 1 | H10 (B) | 10-OH (B) |
| 4.92 | m | 1 | 1-OH (B) | H1 (B) |
| 1.14 | H6, H10 (A) | H7, 10-OH (A) | ||
| 4.83 | dd/7.2,8.0 | 0.15 | H2 (A) | H1a, H1b (A) |
| 4.64 | d/7.4 | 1 | H2 (B) | H1 (B) |
| 4.04 | dd/3.0,7.4 | 1 | H1 (B) | H2, 1-OH (B) |
| 2.93 | q/7.2 | 0.15 | H14 (A) | H16 (A) |
| 2.83 | q/7.1 | 1 | H14 (B) | H16 (B) |
| 2.75 | dd/7.2,15.2 | 0.15 | H1a (A) | H1b, H2 (A) |
| 2.15 | m | 1 | H7a (B) | H7b, H8 (B) |
| 2.02 | m | 1.14 | H7 (A) | H8 (A) |
| 1.96 | m | 1 | H7b (B) | H6, H7a, H8 (B) |
| 1.81 | dd/8.0,15.2 | 0.15 | H1b (A) | H1a, H2 (A) |
| 1.72 | m | 1 | H8 (B) | H7a, H7b (B) |
| 0.15 | H8 (A) | H7 (A) | ||
| 1.11 | m | 3 | H16 (B) | H14 (B) |
| 0.51 | H16 (A) | H14 (A) | ||
| 1.03 | s | 9 | H18, H19, H20 (B) | |
| 1.53 | H18, H19, H20 (A) |
a(A): H assigned ginkgolide A; (B): H assigned ginkgolide B.