The conjugated-unconjugated tautomerism of β-ketoester enamines has been investigated. Enamines with different amine ring size, ketone ring size, and ester alkyl group have been prepared. Equilibrium ratios of the conjugated and unconjugated forms have been determined. A three-point rationalization is presented:(1) the relative instability of the conjugated form is due to a large steric interaction;(2) the ring size combination largely ...
