Table 2.
Experimental observables for residue A of the ΔUA containing disaccharides 3–5.
| 3 | 4 | 5 | ||||
|---|---|---|---|---|---|---|
| Residue A | NMR | Theoretical | NMR | Theoretical | NMR | Theoretical |
| 3J coupling (Hz)a | ||||||
| H1–H2 | 3.4 | 2.7 | 3.0 | 2.7 | 3.7 | 2.9 |
| H2–H3 | 2.5 | 2.5 | 2.5 | 2.8 | 2.8 | |
| H3–H4 | 4.7 | 5.0 | 4.7 | 5.0 | 4.4 | 4.8 |
| Population (1H2:2H1) | 70:30 | 80:20 | 76:24 | 80:20 | 67:33 | 76:24 |
| NOEs (Å) | ||||||
| H1A–H3B | 3.5 | 2.7 | 3.3 | 2.4 | 2.9 | |
| H1A–H5B | 3.5 | 3.1 | 3.6 | 3.3 | ||
a
J couplings for H1–H2, H2–H3, and H3–H4 in the 1H2 ring form are 1.7, 1.2, and 5.8 Hz, respectively, and for the 2H1 form are 6.7, 7.8, and 1.6 Hz, respectively. The J values were independent of the anomeric configuration (α or β) at the reducing terminus.