Identifiable 1H chemical shifts forA, M3a, M3b, M3c,andM6b All δ values are referenced to the CD2HCN resonance set at 1.95 ppm. M3c δ values are referenced to the O-Me peak, which was set to 3.87 ppm.
Position | A | M3a | M3b | M3c (LC-NMR) | M6b |
|---|---|---|---|---|---|
| Pyr-3 | 6.87 | 6.83 | 6.81 | 6.90 | 6.75 |
| Pyr-4 | 7.73 | 7.70 | 7.68 | 7.72 | 7.61 |
| Pyr-6 | 8.05 | 8.10 | 8.10 | 8.04 | 8.10 |
| Prop-β-CH | 5.27 | 5.20 | 5.19 | 5.25 | 5.32 |
| Prop-α-CH2 | 2.73, 2.83 | 2.86, 2.94 | 2.86, 2.93 | 2.74, 2.81 | 2.79, 3.04 |
| 3 | 6.51 | 6.67 | 6.66 | 6.72 | 6.84 |
| 4 | 7.41 | 7.70 | 7.74 | 7.59 | 7.46 |
| 5 | 2.68 | 4.62 | 4.61 | 2.75 | 2.87 |
| 6 | 1.84 | 1.81 | 1.80 | 1.70 | 2.54 |
| 7 | 3.39 | 3.41 | 3.42 | 5.24 | |
| 1′-CH2 | 3.12, 3.08 | 3.08 | 3.10 | 3.1, 3.06 | 3.01 |
| 2′-CH2 | 1.88, 1.81 | 1.75 | 1.73 | 1.85 | 1.87 |
| 3′-CH2 | 2.65, 2.55 | 2.60 | 2.60 | 2.73, 2.61 | 2.63 |
| Imid-CH2s | 3.17, 3.46 | 3.45 | 3.35 | 3.16, 3.43 | 3.21, 3.36 |
| 2.95, 3.33 | 3.20 | 3.19 | 2.94, 3.30 | 2.92, 3.30 | |
| O-Me | 3.87 | 3.82 | 3.82 | 3.87 | 3.88 |
Pyr, pyridine; Imid, imidazolidine; Prop, propionic acid moieties.