Transformation of Oximes of Phenethyl Ketone Derivatives to Quinolines and Azaspirotrienones Catalyzed by Tetrabutylammonium Perrhenate and Trifluoromethanesulfonic Acid
quinolines by the treatment with tetrabutylammonium perrhenate, trifluoromethanesulfonicacid, and chloranil in refluxing 1,2-dichloroethane. Azaspirotrienones can be synthesized from p-hydroxyphenethyl or 3-(p-hydroxyphenyl)propyl ketone oximes by applying the above method. Thus prepared azaspirotrienones are converted to quinolines by acid treatment.
Isomerization of oxime derivatives was researched in detail to find out the methods for the syn-anti isomerization of O-substituted oximes. Based on these findings were developed simple methods for the preparation of aza-heterocycles from both stereoisomers of oximes. Quinolines were synthesized from β-aryl ketone oximes by treatment with trifluoroacetic anhydride and 4-chloranil. γ,δ-Unsaturated O-methoxyacetyloximes were transformed to 2H-dihydropyrroles by reaction with methoxy-acetic acid.