Synthesis of Azaspirodienones via Intramolecular Cyclization of p-Hydroxybenzylacetone Oximes and Their Transformation into Quinolines

Abstract
Intramolecular cyclization reaction on the nitrogen atom of oximes of p-hydroxybenzylacetone derivatives proceeds by the treatment with tetrabutylammonium perrhenate and trifluoromethanesulfonic acid in refluxing 1,2-dichloroethane to afford azaspirodienones in good yield. The azaspirodienones are transformed into quinolines via dienone-phenol rearrangement.