Table 2.
Comparison of interproton distances determined by NOEs for plakilactone H (2) in CDCl3 with DFT-calculated values for 2b and 2c. Values in bold were used to calibrate the NOEs.
| 2b | 2c | |||||
| proton | exp RNOE (Å) | Rcalcd (Å) | ABS % errora | Rcalcd (Å) | ABS % errora | |
| H16 | H15b | 2.75 | 2.75 | – | 2.75 | – |
| H8 | H9 | 2.68 | 2.73 | 1.8% | 2.72 | 1.5% |
| H8 | H10 | 3.27 | 3.02 | 7.9% | 2.95 | 10.1% |
| H8 | H6 | 2.32 | 2.44 | 4.9% | 3.80 | 48.4% |
| H7 | H9 | 2.65 | 2.71 | 2.1% | 3.93 | 38.7% |
| H7 | H10 | 3.60 | 3.39 | 6.1% | 4.71 | 26.8% |
| H7 | H6 | 2.94 | 3.03 | 2.9% | 3.07 | 4.2% |
| MAEb | 4.7% | 20.7% | ||||
| STD | 2.9% | 17.3% | ||||
a|% error| = |Rcalcd − RNOE|/[(Rcalcd + RNOE)/2], absolute differences for calculated versus NOE-derived distances/calculated distances. bMAE = Σ[% error]/n.