Organic anions. Part 1. Equilibration of 1,3-diarylpropenes
A number of 1,3-diarylpropenes, potential precursors of the allylic anions (I). have been synthesised, and the base catalysed equilibration between the double bond isomers (II) and (III) has been investigated. The equilibrium constants correlate satisfactorily with the substituent constant σ. N.m.r. shift reagents aided spectroscopic analysis of certain mixtures.