Research Article
Differentiation between 6- and 7-Membered Rings Based on Theoretical Calculation of NMR Parameters
Table 3
DFT-calculated and experimental
13C NMR chemical shifts (
/ppm) for
1 and
2.
| | Cmpd, conf. | | C-2 | C-3 | C-4 | C-5a | C-6 | C-7 | C-8 | C-9 | C-9a |
| | 1 | 1 | 67.0 | 52.0 | 62.9 | 135.3 | 117.1 | 121.6 | 121.7 | 118.0 | 148.1 | | 2 | 63.8 | 56.7 | 60.4 | 131.5 | 120.6 | 122.5 | 122.4 | 119.0 | 148.7 | | 3 | 65.0 | 52.2 | 62.1 | 134.5 | 116.8 | 122.4 | 119.3 | 117.5 | 147.2 | | 4 | 64.1 | 51.3 | 60.4 | 133.6 | 115.2 | 122.3 | 119.7 | 117.7 | 147.3 | | 5 | 62.6 | 51.7 | 62.1 | 134.9 | 114.3 | 122.0 | 119.0 | 117.8 | 147.0 | | 6 | 69.9 | 52.3 | 71.8 | 139.3 | 115.1 | 124.0 | 118.1 | 117.6 | 147.6 | | PWA | 66.2 | 52.6 | 62.6 | 134.8 | 117.3 | 121.9 | 121.3 | 118.1 | 148.0 | | exp. [12] | 66.1 | 51.4 | 63.0 | 132.9 | 116.1 | 121.9 | 119.3 | 116.9 | 144.1 |
| | 2 | 1 | 76.0 | 67.9 | 54.2 | 146.9 | 120.1 | 124.9 | 123.7 | 124.1 | 156.7 | | 2 | 76.0 | 69.0 | 52.9 | 143.2 | 117.3 | 123.7 | 121.2 | 122.4 | 153.1 | | 3 | 76.1 | 71.3 | 53.5 | 143.3 | 117.0 | 123.7 | 120.7 | 121.8 | 151.8 | | PWA | 76.0 | 68.1 | 54.1 | 146.6 | 119.8 | 124.8 | 123.5 | 123.9 | 156.3 | | exp. [12] | 75.4 | 68.6 | 52.4 | 142.0 | 120.0 | 124.1 | 122.1 | 122.2 | 150.7 |
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Legend: PWA, population-weighted average.
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