Synthesis and thermolysis of the 2,3-dihydro-1H-pyrole-2,3-diones, pseudopericyclic reactions of formyl(N-phenylimidoyl)ketene: Experimental data and PM3 calculations.

Saripinar E., KARATAS S.

JOURNAL OF HETEROCYCLIC CHEMISTRY, cilt.42, sa.5, ss.787-796, 2005 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 42 Sayı: 5
  • Basım Tarihi: 2005
  • Doi Numarası: 10.1002/jhet.5570420507
  • Dergi Adı: JOURNAL OF HETEROCYCLIC CHEMISTRY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.787-796
  • Erciyes Üniversitesi Adresli: Evet

Özet

The reactions of the 2,3-dihydro-1H-furan-2,3-dione 1 with Schiff bases 2a-f at 60-70 degrees C furnish the corresponding 2,3-dihydro-1H-pyrole-2,3-diones 3a-f. The heating of 3a-d afforded the corresponding 4-methoxybenzoyl(N-arylimidoyl)ketenes 4a-d as intermediates which undergo a very facile cyclization to quinoline-4-ones 5a-d. According to our PM3 calculations, fragmentation of 4-formyl-2,3-dihydro-1H-pyrole-2,3-dione and 1,4-cyclization of formyl(N-phenylimidoyl)ketene IN1 to azetin-2-one IN2 and oxetone IN3 are pseudopericyclic reactions with two orbital connections, proceed via planar transition structures. Due to to the possibility of syn and anti conformations of the imine phenyl, there are eight E/Z-isomers of IN1. In addition, we have also calculated reaction mechanism of formation of quinoline-4-ones by the PM3 method.