Using this information, we can propose a structure for the compound:
This write-up synthesizes the core principles and methodologies found in standard educational PDFs on 2D NMR structure elucidation, such as those by Field, Sternhell, and Kalinowski, or problem sets from university courses. organic structures from 2d nmr spectra pdf
| Pitfall | Solution | | :--- | :--- | | | Check for linear or conjugated systems (e.g., H-C≡C-C=O gives 4J). Use a second correlation to confirm. | | Overlooking fast exchange (OH, NH) | These protons often lack COSY or HMBC cross-peaks. Detect them via chemical shift variability or D2O exchange. | | Assuming all cross-peaks are real | Check for artifacts (e.g., t1 noise, folded peaks). Run a ^13C -decoupled HMBC for cleaner data. | | Misassigning diastereotopic protons | In a chiral molecule, two geminal protons (CH2) will have different ^1H shifts and different HSQC correlations to the same carbon. Use NOESY/ROESY to distinguish them. | Using this information, we can propose a structure