Selective Excitation 1D-NMR Experiments for the Assignment of the Absolute Configuration of Secondary Alcohols

Abstract

Routine selective excitation experiments, easy to set up on modern NMR spectrometers, allow for the determination of the absolute configuration of chiral secondary alcohols by double derivatization directly in the NMR tube. As a general method, TOCSY1D with selective excitation of the α proton in the MPA esters and with a short mixing time reveals only the nearby protons in the coupling network. Typically, the analysis takes less than 30 min. A longer mixing time, selective excitation of other signals, or NOESY1D experiments can be used for measuring Δδ<i>RS</i> of other protons