Table 1. NMR spectroscopic data for rufescenolide C (1) in CDCl3.
| Positiona | δC(mult.)b | δH(mult., J, Hz)c | COSY (H→H)d | HMBC (H→C)e | NOESY (H→H)f |
|---|---|---|---|---|---|
| 1a | 205.0 C | ||||
| 2a | 104.9 CH | 5.70 s | 1a, 3a, 10a | 8a | |
| 3a | 187.2 C | ||||
| 4a | 130.6 C | ||||
| 5a | 135.0 CH | 5.98 br s | 6a | 15a | 15a |
| 6a | 81.9 CH | 5.25 m | 7a | 8a | 8a |
| 7a | 51.3 CH | 3.70 m | 6a, 8a | 6a, 9a-b, 13a-a | |
| 8a | 74.2 CH | 4.47 dt (2.0, 12.0) | 7a, 9a | 6a, 10a, 1′a | 6a, 9a-a, 9a-b |
| 9a-a | 44.2 CH2 | 2.26 m | 8a, 9a-b | 1a, 8a, 10a, 14a | 8a |
| 9a-b | 2.50 t (12.0) | 8a, 9a-a | 1a, 8a, 10a, 14a | 7a, 8a, 14a | |
| 10a | 89.8 C | ||||
| 11a | 133.8 C | ||||
| 12a | 168.8 C | ||||
| 13a-a | 124.5 CH2 | 5.42 d (2.4) | 7a, 12a | 7a | |
| 13a-b | 6.23 d (3.2) | 7a, 12a | |||
| 14a | 20.9 CH3 | 1.52 s | 1a, 9a, 10a | ||
| 15a | 20.5 CH3 | 2.07 s | 3a, 4a, 5a | 5a | |
| 1′a | 166.3 C | ||||
| 2′a | 137.9 C | ||||
| 3′a-a | 128.5 CH2 | 5.76 br s | 1′a, 2′a, 4′a | 4′a-a, 4′a-b | |
| 3′a-b | 6.12 br s | 1′a, 2′a, 4′a | |||
| 4′a-a | 30.8 CH2 | 2.22 m | 5b | 1′a, 2′a, 3′a, 4b, 5b, 6b | 3′a-a, 15b |
| 4′a-b | 2.73 m | 5b | 1′a, 2′a, 3a′, 4b, 5b, 6b | 3′a-a | |
| 1b | 205.7 C | ||||
| 2b | 105.9 CH | 5.70 s | 1b, 3b, 10b | 6b, 8b, 15b | |
| 3b | 193.8 C | ||||
| 4b | 36.3 CH | 2.85 m | 5b, 15b | 3b, 5b, 6b, 15b | |
| 5b | 46.3 CH | 2.63 m | 4′a, 6b | 6b, 7b, 15b, 2′a | 7b, 14b |
| 6b | 81.0 CH | 4.28 dd (3.6, 7.2) | 5b, 7b | 8b, 11b, 12b, 13b | 2b, 7b, 15b |
| 7b | 55.9 CH | 3.40 m | 6b, 8b | 5b, 6b, 8b, 13b-a | |
| 8b | 72.4 CH | 4.36 dt (2.0, 11.2) | 7b, 9b | 6b, 10b, 1′b | 7b, 9b-b |
| 9b-a | 45.8 CH2 | 2.35 m | 8b, 9b-b | 1b, 8b, 10b, 14b | |
| 9b-b | 2.63 m | 8b, 9b-a | 1b, 8b, 10b, 14b | 8b | |
| 10b | 90.1 C | ||||
| 11b | 133.3 C | ||||
| 12b | 169.2 C | ||||
| 13b-a | 125.2 CH2 | 5.47 d (2.4) | 7b, 12b | 7b | |
| 13b-b | 6.17 d (2.8) | 7b, 12b | |||
| 14b | 21.2 CH3 | 1.51 s | 1b, 9b | 5b | |
| 15b | 9.9 CH | 1.25 (overlap) | 4b | 3b, 4b, 5b | 2b, 6b, 4′a-a |
| 1′b | 166.9 C | ||||
| 2′b | 135.7 C | ||||
| 3′b-a | 126.4 CH2 | 5.51 br s | 1′b, 2′b, 4′b | 4′b | |
| 3′b-b | 5.98 brs | 1′b, 2′b, 4′b | |||
| 4′b | 18.1 CH3 | 1.81 s | 1′b, 2′b, 3′b | 3′b-a |
a
Assigned by analysis of 1H, 13C, DEPT 90, DEPT 135, COSY, HSQC, and HMBC NMR spectra.
b
Recorded at 100.6 MHz and referenced to residual CDCl3 at δ 77.16.4 CH3, CH2, CH, and C determined by DEPT 90 and DEPT 135 and HSQC experiments.
c
Recorded at 400.1 MHz and referenced to residual CDCl3 at δ 7.26.4 The overlapped signals were assigned by 1H–1H COSY, HSQC, and HMBC spectra are presented without designating multiplicity.
d
Recorded at 400.1 MHz and referenced to residual CDCl3 at δ 7.26 with proton showing COSY correlation to indicated proton.
e
Recorded at 800.1 MHz with proton showing HMBC correlation to indicated carbon.
f
Recorded at 800.1 MHz and referenced to residual CDCl3 at δ 7.26 with proton showing NOESY correlation to indicated proton.