Table 1.
1H and 13C NMR spectroscopic data of 1–3 recorded in DMSO-d6 (δ in ppm).
| Position | 1 a | 2 b | 3 a | |||
|---|---|---|---|---|---|---|
| δH (J in Hz) | δC | δH (J in Hz) | δC | δH (J in Hz) | δC | |
| 2 | 163.4 | 5.62, dd (12.6, 3.0) | 78.7 | 5.55, dd (13.0, 3.0) | 78.4 | |
| 3ax | 7.03, s | 104.9 | 3.31, dd (17.4, 13.2) | 42.2 | 3.31, overlapped | 42.8 |
| 3eq | 2.82, dd (16.8, 3.0) | 2.83, dd (17.0, 3.0) | ||||
| 4 | 182.4 | 197.1 | 198.7 | |||
| 5 | 152.8 | 154.4 | 148.3 | |||
| 6 | 130.6 | 128.3 | 136.1 | |||
| 7 | 159.3 | 161.1 | 139.5 | |||
| 8 | 6.97, s | 91.6 | 6.30, s | 92.0 | 6.27, s | 106.4 |
| 9 | 152.3 | 158.3 | 153.0 | |||
| 10 | 105.3 | 102.5 | 106.2 | |||
| 1′ | 130.6 | 138.5 | 138.8 | |||
| 2′ | 8.11, dd (7.0, 1.5) | 126.4 | 7.54, d (7.2) | 126.6 | 7.53, dd (8.5, 1.5) | 126.5 |
| 3′ | 7.58–7.63, m | 129.1 | 7.44, dd (7.2, 7.2) | 128.5 | 7.37–7.44, m | 128.5 |
| 4′ | 132.1 | 7.40, m | 128.6 | 128.4 | ||
| 5′ | 129.1 | 7.44, dd (7.2, 7.2) | 128.5 | 128.5 | ||
| 6′ | 8.11, dd (7.0, 1.5) | 126.4 | 7.54, d (7.2) | 126.6 | 7.53, dd (8.5, 1.5) | 126.5 |
| 1″ | 4.46, d (7.5) | 68.3 | 4.35, d (7.2) | 68.4 | 3.26, overlapped | 28.7 |
| 2″ | 5.45, m | 120.5 | 5.42, m | 120.6 | 5.24, m | 121.1 |
| 3″ | 137.4 | 137.1 | 132.7 | |||
| 4″ | 1.71, s | 25.4 | 1.70, s | 25.4 | 1.69, s | 25.4 |
| 5″ | 1.63, s | 17.7 | 1.61, s | 17.7 | 1.65, s | 17.6 |
| 5-OH | 12.77, s | 11.94, s | 11.71, s | |||
| 6-OH | 8.51, s | |||||
| 7-OCH3 | 3.94, s | 56.5 | 3.83, s | 56.3 | ||
a NMR at 500/125 MHz. b NMR at 600/125 MHz.