Neighboring group participation by the pyrrole nucleus
Using proton and carbon-13 NMR spectroscopy, the transformation of 2-hydroxyethylpyrroles (5,15) into 2-haloethylpyrroles by treatment with thionyl chloride or carbon tetrabromide/triphenylphosphine is shown to proceed by randomization of the two side-chain carbon atoms. A spirocyclopropylpyrrolium ion (19) is postulated as an intermediate in this unexpected process. © 1981.
Publication Source (Journal or Book title)
Smith, K., Martynenko, Z., & Tabba, H. (1981). Neighboring group participation by the pyrrole nucleus. Tetrahedron Letters, 22 (14), 1291-1294. https://doi.org/10.1016/S0040-4039(01)90299-0