Table 1.
NMR Spectroscopic Data for Nitropyrrolins A-E (1–5) [500 MHz, CDCl3 (δ 7.27), δH mult (J in Hz)]
| 1 | 2 | 3 | 4 | 5 | |
|---|---|---|---|---|---|
| 1 | 9.49, br s | 9.51, br s | 9.48, br s | 9.38, br s | 9.58, br s |
| 3 | 7.06, br s | 7.03, br s | 7.07, br s | 7.01, br s | 7.08, br s |
| 5 | 6.90, br s | 6.87, br s | 6.92, br s | 6.84, br s | 6.92, br |
| 1′ | 2.73, br dd (15.0, 2.0) | 2.71, dd (15.0, 6.0) | 2.93, dd (15.0, 1.5) | 2.72, ma | 2.94, dd (15.0, 2.0) |
| 2.53, dd (15.0, 10.5) | 2.68, dd (15.0, 6.0) | 2.60, dd (15.0, 10.5) | 2.60, dd (15.0, 10.5) | ||
| 2′ | 3.58, br dd (10.5, 2.0) | 2.94, dd (6.0, 6.0) | 3.75, dd (10.5, 1.5) | 4.18, dd (6.5, 6.5) | 3.76, br d (10.5) |
| 4′ | 1.73, br ddd (14.0, 10.5, 6.0) | 1.70, ddd (13.5, 8.0, 6.0) | 2.00, m | 5.38, dd (7.0, 7.0) | 1.98, ddd (14.0, 11.0, 5.0) |
| 1.49, br ddd (14.0, 10.5, 6.0) | 1.49, ddd (13.5, 9.5, 6.5) | 1.75, ddd (14.0, 11.0, 5.0) | 1.72, ddd (14.0, 11.0, 5.0) | ||
| 5′ | 2.20, m | 2.11, m | 2.28, m | 2.73, ma | 2.29, ma |
| 2.14, m | 2.19, m | 2.19, ma | |||
| 6′ | 5.18, br t (7.0) | 5.08, ma | 5.15, td (7.0, 1.0) | 5.08, ma | 5.22, dd (7.0, 7.0) |
| 8′ | 2.01, m | 2.05, m | 1.99, m | 1.99, m | 2.27, ma |
| 2.09, ddd (15.0, 8.0, 8.0) | |||||
| 9′ | 2.09, m | 1.96, br dd (8.0, 7.0) | 2.08, dd (7.5, 7.5) | 2.07, m | 1.60, ma |
| 1.42, dddd (14.0, 10.0. 8.0, 5.0) | |||||
| 10′ | 5.10, tq (7.0, 1.0) | 5.08, ma | 5.09, tq (7.0, 1.5) | 5.09, ma | 3.36, dd (10.0, 1.5) |
| 12′ | 1.69, br d (1.0) | 1.68, br d (1.0) | 1.69, s | 1.69, s | 1.22, s |
| 13′ | 1.61, s | 1.60, s | 1.61, s | 1.61, s | 1.18, s |
| 14′ | 1.65, s | 1.60, s | 1.63, s | 1.63, s | 1.66, s |
| 15′ | 1.27, s | 1.38, s | 1.64, s | 1.71, s | 1.62, s |
a
The multiplicity of this signal was unresolved due to peak overlapping and the chemical shift was assigned by interpretation of HSQC and HMBC spectroscopic data.