The retro-Nazarov reaction.
Treatment of 2-bromo-4-t-butoxy-2-cyclopentenone with an amine base in refluxing trifluoroethanol afforded a ring-opened product in moderate yield. The mechanism of the reaction has been formulated as a retro-Nazarov reaction in which an oxyallylic cation undergoes ring-opening to a dienone. Several other examples of the reaction have been established through a protocol involving the conjugate addition of an organocuprate to 2-bromo-4-t-butoxy-2-cyclopentenone followed by treatment of the adducts with base in refluxing trifluoroethanol.
Harmata
Michael
M
Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211, USA. harmatam@missouri.edu
Lee
Dong Reyoul
DR