Enhanced C-13 resolution in semi-selective HMBC: a band-selective, constant-time HMBC for complex organic structure elucidation by NMR

A semi-selective 2D HMBC experiment is described which yields high-resolution in the indirect carbon-13 dimension by suppressing homonuclear proton coupling modulations and so provides an NMR technique suitable for the structure elucidation of organic compounds which exhibit particularly crowded carbon-13 spectra.