13C NMR-Based Approaches for Solving Challenging Stereochemical Problems

Determining the configuration of proton-deficient molecules is challenging using conventional NMR methods including nuclear Overhauser effect (NOE) and the proton-dependent J-based configuration analysis (JBCA). The problem is exacerbated when only one stereoisomer is available. Alternative methods based on the utilization of 13C NMR chemical shifts, 13C–13C homonuclear couplings measured at natural abundance, and residual chemical shift anisotropy measurements in conjunction with density functional theory calculations are illustrated with a proton-deficient model compound.