title: Synthesis and chemistry of unusual bicyclic endoperoxides containing the pyridazine ring.
abstract: Inverse-Diels-Alder reaction of dimethyl 1,2,4,5-tetrazine-3,6-dicarboxylate with unsaturated bicyclic endoperoxides gave the bicyclic endoperoxides containing the pyridazine ring. The NEt(3) and CoTPP (TPP = tetraphenylporphyrin) catalyzed reaction of endoperoxide 8 resulted in the formation of hydroxy ketone 11 and cis-diol 9. Cleavage of the peroxide linkage in 8 with thiourea provided cis-diol 9. Oxidation of hydroxy ketone 11 and cis-diol 9 led to the phthalazine-5,8-dione 10. Furthermore, the various transformations of the other endoperoxides 19, 20, 22, 23, and 30 resulted in the formation of pyridazine derivatives.
authors.affiliation: Department of Chemistry, Faculty of Art and Sciences, Atatürk University, 25240 Erzurum, Turkey.
authors.forename: Galip
authors.initials: G
authors.lastname: Ozer
authors.forename: Nurullah
authors.initials: N
authors.lastname: Saraçoğlu
authors.forename: Metin
authors.initials: M
authors.lastname: Balci