Vicinal c-h coupling as an aid to stereochemical assignments in substituted propenoic acids

Abstract

Two isomeric pairs of 3-bromopropenoic acids were prepared and vicinal C-H couplings were measured in their 13C n.m.r. spectra. Complete C-H coupling schemes were also obtained for these and several other propenoic acids. It was seen that the ranges for 3Jtrans and 3Jcis did not overlap, and so a stereochemical assignment based upon n.m.r. data for a single isomer can be made with confidence. © 1993 ASEG.