| NMR | δppm | Splitting pattern | Integration | J(Hz) | Chat Forum |
| Ha | 1.34 | s | 3H |  The three protons in either of the three methyl group are homotopic with no neighbors that are less than 3 bond distance away, thus they only have a single peak with an integration of 3.Note: Without given coupling constants, the chemical shifts of Ha and Hb are indistinguishable due to their similar chemical environment. |
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| Hb | 1.37 | s | 3H | ||
| Hc | 1.44 | s | 3H |  The three homotopic protons in this methyl group are more deshielded than the Ha and Hb because they are 2 bond distance away from the electronegative O atom. The protons only emit a single peak because there is no neighbors that are less than 3 bond distance away from this methyl group. |
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| Hd | 1.63-1.81 | m | 2H |  Although these two protons (exo and endo) are diastereotopic, it is hard to differentiate the two due to their similar chemical environment. Compare to Hf exo-endo pair, the Hd exo-endo pair is further from the electronegative region (C=C and ester) of the molecule, thus is expected to have a lower chemical shift than its comparative. |
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| He | 2.13 | tt (possible alternative: ddd) | 1H | J=3.9, 2.2 Hz (may be missing a J~3-6Hz) | This proton has four 2-bond neighbors: Hd exo-endo pair and Hg exo-endo pair. Presumably, only coupling between He and Hg(exo) (J=3.9Hz) and Hd(exo) (J=3~6Hz) that are equatorial to the ring are observable. Considering He and Hh may constitute a W pattern, it is also possible that He couples with Hh despite they are 4 bond apart (J=2.2Hz). |
| Hf | 2.23-2.48 | m | 2H |  These two protons are diastereotopic: one is in the exo and one is in the endo configuration. It is, however, hard to distinguish them without assignable coupling constants.
Theoretically, the Hf exo-endo pair may couple with one another and with the Hd exo-endo pair, resulting in a ddd splitting pattern. However, only Hf(endo) may couple with Hh, if a 4-bond W-pattern coupling is possible.
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| Hg(exo) | 2.93 | dd | 1H | J=14.8, 4.0Hz | Hg(exo) couples with its endo counterpart (J=14.8Hz) and He (J=4.0Hz). |
| Hg(endo) | 2.98 | d | 1H | J=1.2 Hz (possible alternative: 14.8Hz) | Unlike Hg (exo), the coupling between Hg (endo) and He is not observable (J~0Hz), leaving it with only a 2-bond neighbor Hg (exo).
The coupling constant should be 14.8Hz rather than 1.2 Hz because the exo-endo pair are geminal protons.
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| Hh | 4.04-4.21 | m (possible alternative: dd) | 1H | Hi is deshielded by the O atom and has a chemical shift around 4ppm. To be more exact, the splitting pattern should be dd because Hh forms two W pattern with two of its 4-bond neighbors He and Hf(endo). |
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| Hi | 4.28 | d | 1H | J=1.6HZ (possible alternative 11.9Hz) | Analogous to the proton in methyl acetate, which typically carries a chemical shift around 4.2ppm, Hj and Hk have similar peaks at 4.28 and 4.65ppm.
Hj couples with Hk and should have a coupling constant of 11.9Hz since they are geminal at the same carbon of the ring.
Note:The chemical shifts 4.28 and 4.65ppm are not definite and may be exchanged between Hj and Hk since both protons share similar chemical environment and splitting pattern.
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| Hj | 4.65 | d | 1H | J=11.9Hz | |
| Hk | 5.93 | d | 1H | J=10.1Hz | This proton has a lower chemical shift than Hl because the electrons on the double bond may delocalize and relocate at the sp2C carrying Hk and push the C=O to the O atom.
The doublet signifies Hk’s 3-bond neighbor Hl.
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| Hl | 6.70 | d | 1H | J=10.1Hz | This proton is more de-shielded than Hk because of resonance between the conjugated C=C and C=O. The formation of an enolate makes the sp2C farther from the O partially positive. This resonance contributes to deshielding of Hl.
The doublet signifies Hl’s 3-bond neighbor Hk.
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ChemChat
1HNMR Correlation
Molecule 49
1H NMR (400 MHz, CDCl3) δ 6.70 (d, J = 10.1 Hz, 1H), 5.93 (d, J = 10.1 Hz, 1H), 4.65 (d, J = 11.9 Hz, 1H), 4.28 (d, J = 1.6 Hz, 1H), 4.21-4.04 (m, 1H), 2.98 (d, J = 1.2 Hz, 1H), 2.93 (dd, J = 14.8, 4.0 Hz, 1H), 2.48-2.23 (m, 2H), 2.13 (tt, J = 3.9, 2.2 Hz, 1H), 1.81-1.63 (m, 2H), 1.44 (s, 3H), 1.37 (s, 3H), 1.34 (s, 3H)