General Strategies for Structure Elucidation by NMR
Example I.
Typical organic compound (40 mgr of strychnine. MW=450) dissolved in a deuterated solvent (CDCl3).
Dual 1H-13C probehead in an AVANCE  250 MHz spectrometer.

Main Objective: Complete and inambiguous assignment of both 1H and 13C spectra.

  1. A conventional 1H spectrum.
  2. 2D 1H-1H COSY to trace out all J-connectivites
  3. 2D NOESY (or 2D ROESY) for all NOE-connectivites. Alternatively, a series of selective NOEDIFF experiments could be also recorded to obtain specific NOE correlations.
  4. A conventional 1H-decoupled 13C-spectrum.
  5. Carbon multiplicity from DEPT-135 and DEPT-90 spectra.
  6. 2D 1H-13C HETCOR spectrum for heteronuclear correlation map.
  7. Long-range 1H-13C connectivites from a 2D 1H-13C  COLOC spectrum.
Notes: Excellent results can be also obtained using inverse-detected correlation experiments instead of the carbon-detected experiments. Thus 2D 1H-13C HMQC and  2D 1H-13C  HMBC experiments can be recorded with improved sensitivity at expense of some degree of quality due to undesired t1-noise.