1,2,4-triazines in organic synthesis. 8. Intramolecular diels-alder reaction of 5-acyl-1,2,4-triazineoxime ethers. New route of synthesis of alkylhetarylketones

Intramolecular diene cycloaddition of 5-acyl-1,2,4-triazineoxime ethers involving a dienophile substituent in the 3-position of the triazine ring is studied. New alkylhetarylketones are synthesized by hydrolysis of the condensed N- and O-containing heterocyclic products. The starting materials are prepared by oxidation of 5-acetyl- and 5-butyryl-3-methylthio-1,2,4-triazineoxime ethers with KMnO₄ to the sulfonyl derviatives with subsequent replacement of the CH₃SO₂ group by sodium 3-butyn-1-oxide, 4-pentyn-1-oxide and o-cyanophenoxide.For Communication 7, see 1].Institute of Chemistry, Agricultural and Teachers University, Siedlce, 08–110, Poland.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 381–389, March, 1999.