1JCC‐edited HSQC‐1,n‐ADEQUATE: a new paradigm for simultaneous direct and long‐range carbon–carbon correlation

Abstract

Establishing the carbon skeleton of a molecule greatly facilitates the process of structure elucidation, leaving only heteroatoms to be inserted, heterocyclic rings to be closed, and stereochemical features to be defined. INADEQUATE, and more recently PANACEA, have been the only means of coming close to the goal of totally defining the carbon skeleton of a molecule. Unfortunately, the extremely low sensitivity and prodigious sample requirements of these experiments and the multiple receiver requirement for the latter experiment have severely restricted the usage of these experiments. Proton-detected ADEQUATE experiments, in contrast, have considerably higher sensitivity and more modest sample requirements. By combining experiments such as 1,1-ADEQUATE and 1,n-ADEQUATE with higher sensitivity experiments such as GHSQC through covariance processing, sample requirements can be further reduced with a commensurate improvement in the s/n ratio and F(1) resolution of the covariance processed spectrum. We now wish to report the covariance processing of an inverted (1)J(CC) 1,n-ADEQUATE experiment with a non-edited GHSQC spectrum to afford a spectrum that can trace the carbon skeleton of a molecule with the exception of correlations between quaternary carbons.