General Strategies for Structure Elucidation by NMR
Example II.
Typical organic compound (10 mgr of strychnine. MW=450) dissolved in a deuterated solvent (CDCl3).
Inverse broadband probehead incorporating Z-gradients in an AVANCE 400 MHz spectrometer.

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

  1. A conventional 1H spectrum.
  2. ge-2D 1H-1H COSY to trace out all J-connectivites
  3. ge-2D NOESY (or 2D ROESY) for all NOE-connectivites. Alternatively, a series of selective ge-1D NOESY 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. ge-2D 1H-13C HMQC spectrum for heteronuclear correlation map. Alternatively, carbon multiplicity and heteronuclear correlation can be simultaneously obtained from a single ge-2D edited-HSQC spectrum.
  7. Long-range 1H-13C connectivites from a ge-2D 1H-13C  HMBC spectrum.
Notes: Useful long-range 1H-15N connectivites can be assigned from an equivalent ge-2D 1H-15N  HMBC spectrum.