Synthesis and chemistry of endoperoxides derived from 3,4-dihydroazulen-1(2H)-one: An entry to cyclopentane-anellated tropone derivatives

Celik, M
Akbulut, N
Balcı, Metin
Reduction of trienone 1 and subsequent treatment with acid in MeOH furnished 1-methoxy-1,2,3,4-tetrahydroazulene (13). Photo-oxygenation of 13 provided the two bicyclic endoperoxides 14 and 15. Pyrolysis of 14 and 15 gave the corresponding bis-epoxides 17 and 18, which have been synthesized also upon treatment with a catalytic amount of CoTPP (TPP = tetraphenylporphyrin). That an unusual endoperoxide-endoperoxide rearrangement has not been observed strongly supports the assumption that the carbonyl group in 2-4 is responsible for this unprecedented endoperoxide-endoperoxide rearrangement. Treatment of the endoperoxides 14 and 15 with a catalytic amount of Et3N at 0 degrees provided the azulenones 22 and 23 in high yield. Attempted cleavage of the O-O peroxide linkage in 14 and 15 with thiourea resulted, contrary to our expectation, in the formation of 22 and 23. That thiourea acts as a base instead of a reducing reagent has been observed for the first time in peroxide chemistry.


Synthesis, characterization, crystal and molecular structure of 1,5-Dihydro-2H-cyclopenta[1,2-b : 5,4-b ']dipyridin-2-imine
Baysal, Akin; Durap, Feyyaz; Gumgum, Bahattin; Yildirim, Leyla T.; Ulku, Dincer; Boga, Ayse Dilek; Özkar, Saim (Wiley, 2007-01-01)
The reaction of 1,5-diliydro-2H-cyclopenta[1,2-b:5,4-b'ldipyridin-2-one (3) with an alkylamine (butvlamine, hexylamine or ethylenediamine) yields, quite unexpectedly and in the absence of catalyst, the novel compound 1,5-dihydro-2H-cyclopentafl,2-b:5.4-b']dipyridin-2-imine (4) as the sole, analytically pure, solid product, which was fully characterized. The structure of 4 was unequivocally solved by single-crystal X-ray-diffraction analysis. The compound crystallizes in a monoclinic cell (space group P 2(1/...
Synthesis and characterizations of N,N,N ',N '-tetrakis (diphenylphosphino)ethylendiamine derivatives: Use of palladium(II) complex as pre-catalyst in Suzuki coupling and Heck reactions
AKBA, OSMAN; DURAP, FEYYAZ; AYDEMİR, MURAT; BAYSAL, AKIN; Guemguem, Bahattin; Özkar, Saim (Elsevier BV, 2009-03-01)
Oxidation of N,N,N',N'-tetrakis(diphenylphosphino)ethylendiamine (1) with elemental sulfur and selenium gives the corresponding sulfide and selenide, respectively, [(Ph2P(E))(2)NCH2CH2N(P(E)Ph-2)(2)] (E: S 1a, Se 1b). Complexes of 1 [(M2Cl4){(Ph2P)(2)NCH2CH2N(PPh2)(2)}] (M: Ni(II) 1c, Pd(II) 1d, Pt(II) 1e) were prepared by the reaction of 1 with NiCl2 or [MCl2(COD)] (M = Pd, Pt). The new compounds were characterized by NMR, IR spectroscopy and elemental analysis. The catalytic activity of Pd(II) complex 1d ...
Chemistry of the benzotropone endoperoxides and their conversion into tropolone derivatives: Unusual endoperoxide rearrangements
Guney, M; Dastan, A; Balcı, Metin (Wiley, 2005-01-01)
The chemistry of two bicyclic endoperoxides, obtained by photooxygenation of 2,3-benzotropone (= 5H-benzocyclohepten-5-one 5) and of its ethyl carboxylate derivative 15, was investigated with the aim of synthesizing the respective benzotropolone derivatives. The reaction of the endoperoxide 10 derived from 5 with thiourea gave the desired benzotropolone, i.e., 6-hvdroxy-5H-benzocyclohepten-5-one (11), in high yield (Scheme 1). On the other hand, the endoperoxide 16 derived from the ethyl carboxylate derivat...
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 and structural characterization of a novel seven-coordinate cobalt(II) complex: 2,9-Bis(ethanolamine)-1,10-phenanthrolinechlorocobalt(II) chloride
BAYSAL, AKIN; AYDEMİR, MURAT; DURAP, FEYYAZ; Özkar, Saim; Yildirim, Leyla Tatar (Elsevier BV, 2011-05-31)
Condensation reaction of 2,9-dicarboxaldehyde-1,10-phenanthroline with 2-aminoethanol followed by NaBH4 reduction yielded the polydentate Schiff base ligand 2,9-bis(ethanolamine)-1,10-phenanthroline in its reduced form. This ligand was characterized by elemental analysis, LC-MS, IR, UV-Vis and NMR spectroscopy. Reaction of the reduced Schiff base ligand with aqueous solution of cobalt(II) chloride affords 2,9-bis(ethanolamine)-1,10-phenanthrolinechlorocobalt(II) chloride in high yield. Single crystals of th...
Citation Formats
M. Celik, N. Akbulut, and M. Balcı, “Synthesis and chemistry of endoperoxides derived from 3,4-dihydroazulen-1(2H)-one: An entry to cyclopentane-anellated tropone derivatives,” HELVETICA CHIMICA ACTA, pp. 3131–3138, 2000, Accessed: 00, 2020. [Online]. Available: