Table 1.
1H-NMR Data of compounds 1–3.
| Proton | 1 a | 2 b | 3 b |
|---|---|---|---|
| 1 | 6.71 s | ||
| 3 | 6.97 s | 7.00 s | |
| 5 | 9.36 d (9.0) | 9.38 d (9.0) | 8.08 d (9.0) |
| 6 | 7.09 dd (9.0, 3.0) | 7.10 dd (9.0, 3.0) | 6.63 dd (9.0, 3.0) |
| 8 | 7.04 d (3.0) | 7.06 d (3.0) | 6.69 d (3.0) |
| 9 | 7.28 d (9.0) | 7.31 d (9.0) | 2.73–2.78 m c |
| 10 | 6.90 d (9.0) | 6.91 d (9.0) | 2.73–2.78 m c |
| 3′ | 6.92 s | 7.00 s | 6.96 s |
| 5′ | 8.96 s | 9.17 d (9.0) | 9.50 d (9.0) |
| 6′ | 7.20 d (9.0) | 7.17 dd (9.0 3.0) | |
| 8′ | 7.02 s | 7.25 d (3.0) | |
| 9′ | 7.20 d (9.0) | 7.66 d (9.0) | 7.53 d (9.0) |
| 10′ | 6.71 d (9.0) | 6.98 d (9.0) | 7.36 d (9.0) |
| 4-OCH3 | 4.10 s | 4.12 s | 3.14 s |
| 4′-OCH3 | 4.10 s | 4.14 s | 4.15 s |
| 7′-OCH3 | 3.92 s | ||
| 8′-OCH3 | 3.76 s |
a 1H-NMR data were measured at 600 MHZ in DMSO-d6 for 1, δ in ppm, J in Hz; b 1H-NMR data were measured at 500 MHZ in DMSO-d6 for 2, in CD3OD for 3, δ in ppm, J in Hz; c overlapped; the number in brackets represented coupling constants.