Synthesis and chemistry of unusual bicyclic endoperoxides containing the pyridazine ring

Ozer, G
Saracoglu, N
Balcı, Metin
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 NEt3 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.


Unusual fragmentation of fulvene endoperoxides with phenyliodosyl bis(trifluoroacetate) (PIFA)
Ozer, G; Saracoglu, N; Balcı, Metin (Wiley, 2003-05-01)
Reaction of unsaturated fulvene endoperoxides with dimethyl 1,2,4,5-tetrazine-3,6-dicarboxylate gave saturated fulvene endoperoxides containing the 1,2-dihydropyridazine ring. Treatment of dihydropyridazine endoperoxides with water followed by phenyliodosyl bis(trifluoroacetate) oxidation provided acrylic acid derivatives and dimethyl pyridazine-3,6-dicarboxylate.
Synthesis of 1,2,3,5- tetrasubstituted pyrrole derivatives via 5-exo-dig type cyclization and stereoselective functionalisation of ferrocene derivatives
Kayalar, Metin; Demir, Ayhan Sıtkı; Department of Chemistry (2005)
A convenient and new method for the synthesis of 1,2,3,5-tetrasubstituted pyrrole derivatives starting from 1,3,-dicarbonyl compounds through acid catalyzed cyclization reaction is described. Alkylation of 1,3-dicarbonyl compound with propargyl bromide followed by one step cyclization with the introduction of primary amines in the presence of catalytic amount of triflouroacetic acid (TFA) affords the corresponding pyrrole derivatives in high yields. The investigations on the studies of developing a new meth...
Synthesis of the possible carcinogenic dihydrodiol and diol epoxide of phthalazine
Ozer, G; Saracoglu, N; Menzek, A; Balcı, Metin (Elsevier BV, 2005-02-07)
Inverse-Diels-Alder reaction of dimethyl 1,2,4,5 -tetrazine-3,6-dicarboxylate with benzene cis-diol gave dihydrodiol coninini 2 the 1,4-dihydropyridazine ring. Attempts at oxidation of the dihydropyridazine ring with PIFA and MnO2, resulted in the formation of 5- and 5,6-dihydroxy-phthalazine derivatives. The oxidation of the dihydropyfidazine ring was achieved by way of photooxygenation. The phthalazine type dihydrodiol is unstable and easily undergoes aromatization. The Diels-Alder reaction of tetrazine w...
Synthesis and structure of cyclopropano-annelated homosesquinorbornene derivatives containing pyramidalized double bonds: Evidence for the sterical effect of a cyclopropyl. group on the degree of C=C double-bond pyramidalization
Saracoglu, N; Talaz, O; Azizoglu, A; Watson, WH; Balcı, Metin (American Chemical Society (ACS), 2005-07-08)
endo- and exo-2,3,4,7-tetrahydro-1H-1,4-methanobenzoeyeloheptene-7-carboxylic acid ethyl esters have been synthesized, and their Diels-Alder cycloaddition reactions with maleic anhydride, dimethyl acetylenedicarboxylate and singlet oxygen have been investigated. The X-ray analysis of four adducts indicated the pyramidalization of the central double bond. Density functional theory calculations on the isolated products and model compounds showed excellent agreement between the experimental and theoretical det...
Addition of trifluoromethyltrimethylsilane to acyl phosphonates: Synthesis of TMS-Protected 1-alkyl-1-trifluoromethyl-1-hydroxyphosphonates and 1-aryldifluoroethenyl phosphates
Demir, Ayhan Sıtkı; Eymur, Serkan (American Chemical Society (ACS), 2007-10-26)
Addition reactions of nucleophilic CF3TMS to acyl phosphonates were investigated. Various acyl phosphonates reacted readily with CF3TMS in the presence of K2CO3 in DMF at rt to give 1-alkyl-2,2,2-trifluoro-1-trimethylsilyloxyethylphosphonate in 70−90% yields. When benzoyl phosphonates were used as starting material, after addition of CF3, the formed alcoholate undergoes phosphonate−phosphate rearrangement to form the acyl anion, followed by elimination of F- to give 1-aryldifluoroethenyl phosphates in 87−97...
Citation Formats
G. Ozer, N. Saracoglu, and M. Balcı, “Synthesis and chemistry of unusual bicyclic endoperoxides containing the pyridazine ring,” JOURNAL OF ORGANIC CHEMISTRY, pp. 7009–7015, 2003, Accessed: 00, 2020. [Online]. Available: