摘要:
AbstractA new merocyanine was prepared by addition of the pyrrolidine enamine of N‐ethoxycarbonylpyrrolidine‐3‐one to 1‐octyne‐3‐one. This addition was regioselective (with an unexpected C‐4 alkylation of the pyrrolidinone‐3‐enamine) and stereospecific (exclusively trans addition to the triple bond). The structure and conformational equilibrium were studied by high resolution proton magnetic resonance (NOE and variable temperature effects). Activation parameters ΔH*, ΔS* and ΔG* are given, and the behaviour on protonation examined.