Table 1.
1H NMR spectroscopic data of compound 2–6 (500 MHz, CDCl3) a.
| Position | 2 | 3 | 4 | 5 | 6 |
|---|---|---|---|---|---|
| H-1 | 5.95 (s) | 5.96 (s) | 5.56 (d, 3.0) | 5.95 (s) | 5.95 (s) |
| H-2 | 2.09 (d, 3.0) | ||||
| H-3α | 3.39 (dd, 12.5, 7.5) | 3.40 (dd, 13, 7.5) | 3.73 (m) | 3.40 (dd, 12.8, 7.5) | 3.40 (dd, 12.5, 7.5) |
| H-3β | 2.30 (dd, 12.5, 1.5) | 2.37 (d, 13) | 2.55 (m) | 2.32 (d, 13) | 2.32 (d, 13) |
| H-4 | 3.02 (m) | 3.09 (m) | 2.67 (m) | 3.05 (m) | 3.03 (m) |
| H-6 | 6.04 (s) | 5.89 (1H,s) | 6.30 (s) | 5.99 (s) | 5.99 (s) |
| H-7 | 2.76 (d, 3.3) | 3.24 (1H,s) | 2.65 (d, 3.5) | 2.84 (d, 4.0) | 2.72 (d, 3.5) |
| H-8 | 5.39 (d, 3.3) | 4.99 (d, 3.3) | 5.17 (d, 3.3) | 5.08 (d, 3.3) | |
| H-9 | 5.09 (s) | 5.49 (s) | 4.47 (s) | 5.52 (s) | 5.43 (s) |
| H-12 | 1.05 (d, 7.5) | 1.05 (d, 7.5) | 1.36 (d, 8.0) | 1.06 (d, 7.0) | 1.05 (d, 6.5) |
| H-13 | 1.45 (s) | 1.46 (3H,s) | 1.45 (s) | 1.45 (s) | 1.49 (s) |
| H-14 | 1.57 (s) | 1.54 (3H,s) | 1.56 (s) | 1.57 (s) | 1.56 (s) |
| H-15 | 2.29 (s) | 1.62 (3H,s) | 1.62 (s) | 1.61 (s) | 1.62 (s) |
| AcO-8 (CH3) | 1.61 (s) | ||||
| RCH2OCO-8b | 4.35 (s) | 3.46 (s) | |||
| N(CH2CH2)2O | 2.78 (m) | ||||
| N(CH2CH2)2O | 3.57 (m) |
a
Data for additional ester groups are provided in the Experimental Section.
b
For compound 5, R = Cl; for compound 6, R = N(CH2CH2)2O. Data are based on DEPT, HSQC, and HMBC experiments.