A very easy and quick NOESY to probe stereo chemistry

There is a much easier way to run NOESY than the old 1D NOE-difference and the 2D NOESY:

  1. first, run a proton spectrum.
  2. with the spectrum on screen, click Acquire, then click Options, then click Setup Selective 1D Experiments.
  3. Follow the menu and its prompts; select the peak(s) that you want to probe.
  4. Click Create Datasets, select Selective gradient NOESY:

selnoesy-setup5. the computer will ask you to confirm some experimental parameters. The default choices are usually good. For each of the peak area that you select, one experiment will be run, and it will be stored under the same sample name, in incremental experiment numbers.

Following is a proton spectrum (blue) of pamoic acid and two selective NOESY spectra. Each took less than 1 minute. You can immediately see which proton is spatially close to the targeted protons (the large negative peak).

pamacid-selnoesy