Table 1.
1H and 13C NMR spectroscopic data of compounds 1–3.
| Position | 1 a | 2 a | 3 a | |||
|---|---|---|---|---|---|---|
| δH (ppm) | δC (ppm) | δH (ppm) | δC (ppm) | δH (ppm) | δC (ppm) | |
| 1 | - | 133.3 | - | 132.0 | - | 130.0 |
| 2 | 6.95 d (J = 1.9 Hz, 1H) | 114.7 | 7.07 d (J = 2.0 Hz, 1H) | 111.5 | 6.97 d (J = 1.9 Hz, 1H) | 116.2 |
| 3 | - | 147.9 | - | 149.3 | - | 146.5 |
| 4 | 6.91 d, 1H | 112.8 | - | 148.3 | - | 147.3 |
| 5 | - | 149.5 | 6.82 d (J = 8.1 Hz, 1H) | 116.3 | 6.80 d (J = 8.1 Hz, 1H) | 116.0 |
| 6 | 6.91 d, 1H | 119.1 | 6.92 dd (J = 8.1, 2.0 Hz, 1H) | 120.7 | 6.85 dd (J = 8.1, 1.9 Hz, 1H) | 121.0 |
| β | 5.31 dd (J = 12.6, 3.0 Hz, 1H) | 80.4 | 5.34 dd (J = 12.8, 3.0 Hz, 1H) | 80.8 | 4.91 d (J = 11.4 Hz, 1H) | 85.3 |
| α | 2.71 dd (J = 17.1, 3.0 Hz,1H) 3.05 dd (J = 17.1, 12.6 Hz,1H) |
44.2 | 2.70 dd (J = 17.1, 3.0 Hz,1H) 3.12 dd (J = 17.1, 12.8 Hz,1H) |
44.3 | 4.50 d (J = 11.4 Hz,1H) | 73.8 |
| β′ | - | 197.7 | - | 197.6 | - | 198.5 |
| 1′ | - | 103.5 | - | 103.2 | - | 102.0 |
| 2′ | - | 164.9 | - | 165.0 | - | 164.6 |
| 3′ | 5.89 d (J = 2.2 Hz, 1H) | 97.3 | 5.89 d (J = 2.2 Hz, 1H) | 97.6 | 5.92 d (J = 2.0 Hz, 1H) | 97.5 |
| 4′ | - | 168.7 | - | 169.8 | - | 168.8 |
| 5′ | 5.87 d (J = 2.2 Hz, 1H) | 96.4 | 5.87 d (J = 2.2 Hz, 1H) | 96.1 | 5.89 d (J = 2.0 Hz, 1H) | 96.4 |
| 6′ | - | 165.6 | - | 165.7 | - | 165.4 |
| 3-OCH3 | - | - | 3.88 s (3H) | 56.7 | - | - |
| 5-OCH3 | 3.86 s (3H) | 56.6 | - | - | ||
a NMR data were recorded in MeOH-d4.