Cyclo-addition des derives nitroses aromatiques aux cyclopentadienones : Dualite reactionnelle chez les derives dialkyles en 2,5

摘要: Abstract Condensation of p.nitrosodimethylaniline with 2,5-dialkyl-3,4-diphenyl-cyclopentadienone 1b (R  C2H5) and 1c CH3) leads initially to unstable (Z)-imino-ketones 3 which can react further along two divergent patnways according the reaction medium. The first pathway involves an intramolecular cyclization intermediates 2-hydroxy- 2-alkyl-5-alkylidene-2,5-dihydropyrroles 7 , followed by a very easy isaomerization into b2-(1 hydroxy- alkyl)-5-alkyl-pyrroles 12 . This pathway, predominates in refluxing aromatic hydrocarbons, provides mostly transformation products alcohols : 2-vinylpyrrole 10 nitrone 13 second takes place dry pyridine is thermal rearrangement imino-ketones 3,5-dialkyl-3,4-diphenyl-Δ-4,5-pyrroline-2-ones, 4b,c analogous one occurring tetra-aryl series, Δ-4,5 pyrroline-2-ones are reduced LiAlH4 Δ-2 pyrrolines 5b,c