Abstract Lithium N-butyl-4-pentenylamide (1) in tetrahydrofuran at 22 C rearranged smoothly to give a mixture (after protonation) of 1-butyl-2-methylpyrrolidine, formed by an unusual cyclization process, and cis-and trans-N-butyl-3-pentenylamine; in the presence of 2.0 molar equiv of hexamethylphosphoramide, the total rate of isomerization was accelerated by a factor of 2.5.
