Pyramidalized double bonds containing endoperoxide linkages: Photooxygenation of dimethyl cis-3,8-dihydroheptalene-3,8-dicarboxylate

Download
1999-09-03
Saracoglu, N
Menzek, A
Sayan, S
Salzner, U
Balcı, Metin
Diels-Alder cyclo;addition utilizing singlet oxygen as the dienophile with dimethyl cis-3,8-dihydraheptalene-3,8-dicarboxylate (5) has been investigated, and monoaddition product 7 has been isolated. The addition of a second singlet oxygen to the cycloheptatriene unit in 7 gave syn-bis(norcaradiene) bis(endoperoxide) 4. H-1 NMR spectral studies and theoretical calculations indicate the increased pyramidalization in syn-4 compared with carbon analogue. The increased pyramidalization results from hyperconjugation between the central pi-bond and the four adjacent C-O bonds and by rehybridization at C3, C4, C5, and C6. Furthermore, the increased reactivity for syn-4, which is probably arising from further folding of the central double band, is also in agreement with theoretical calculations.
JOURNAL OF ORGANIC CHEMISTRY

Suggestions

HINDERED LIGAND MOVEMENTS IN TRANSITION-METAL COMPLEXES DECARBONYL (ETA-4-DIENE) TUNGSTEN(0)
Özkar, Saim; KREITER, CG (1992-08-04)
1,2-Bis(dimethylphosphino)ethane-dicarbonyl-eta-4-diene-tungsten(0) complexes (diene = 1,3-butadiene (1), E-1,3-pentadiene (2), E,E-2,4-hexadiene (3) and E-2-methyl-1,3-pentadiene (4)) were synthesized by UV irradiation of 1,2-bis(dimethylphosphino)ethane-tetracarbonyltungsten(0) and the corresponding dienes in toluene. The constitutions of these complexes were determined by IR and NMR spectroscopy (H-1, C-13, P-31). The spectral data indicate pseudo-octahedral structures for the complexes. When the dienes ...
Covalent immobilization of alpha-amylase onto poly(2-hydroxyethyl methacrylate) and poly(styrene-2-hydroxyethyl methacrylate) microspheres and the effect of Ca2+ ions on the enzyme activity
Tumturk, H; Aksoy, S; Hasırcı, Nesrin (2000-02-01)
alpha-Amylase (1,4-alpha-D-glucan-glucanohydrolase; EC 3.2.1.1, Type VI-B from porcine pancreas, extra pure 29 units mg(-1)) was covalently immobilized on poly (2-hydroxyethyl methacrylate), p(HEMA), and poly (styrene-2-hydroxyethyl methacrylate), p(St-HEMA) microspheres, which were activated by using epichlorohydrin (ECH). The properties of the immobilized enzyme were investigated and compared with those of the free enzyme. For the assays carried out at 25 degrees C and pH 6.9, the relative activities were...
Insertion of Fischer Carbene Complexes into the Carbon-Carbon Bond of 1,2-Diphenylcyclopropenone: Formation of Cyclobutenones and o- and p-Methoxyphenol Derivatives
Zora, Metin (American Chemical Society (ACS), 1994-08-01)
Thereactionbetween1,2-diphenylcyclopro-penoneandFischercarbenecomplexeshasbeeninves-tigated.Thereactionproducedamixtureofdipheny-lacetyleneandcyclobutenones.Whena,ß-unsaturatedcarbenecomplexeswereemployed,benzannulationprod-uctsanddiphenylacetylenewereproduced.Amecha-nisminvolvingmetallacyclobutenoneformation,followedbyeithercarbeneinsertionandreductiveeliminationorfragmentationhasbeenproposed.Recently,wereportedthatcarbon—carbonbondin-sertionisthemajorreactionpathwaywhenFischercarbenecomplexesreactwith1,2-...
The Pb-12(2-) and Pb-10(2-) zintl ions and the M@Pb-12(2-) and M@Pb-10(2-) cluster series where M = Ni, Pd, Pt
Nalbant Esentürk, Emren; Eichhorn, Bryan (2006-07-19)
Ethylenediamine (en) solutions of K4Pb9 react with toluene solutions of ML4 (M = Pt, Pd, L = PPh3; M = Ni, L-2 = COD) and 2,2,2-crypt to give M@Pb-12(2-) cluster anions (M = Pt (1), Pd (2), Ni (3)) as the [K(2,2,2-crypt)](+) salts in low (Ni) to good (Pt) yields. The ions have near perfect I-h point symmetry and have been characterized by X-ray diffraction, Pb-207 NMR and LDI-TOF mass spectrometry studies. For M = Ni, the primary product formed is the D-4d Ni@Pb-10(2-) cluster that has also been structurall...
Synthesis and characterizations of N,N-bis(diphenylphosphino)ethylaniline derivatives and X-ray crystal structure of palladium (II), platinum (II) complexes
DURAP, FEYYAZ; BİRİCİK, NERMİN; Guemguem, Bahattin; Özkar, Saim; Ang, Wee Han; Fei, Zhaofu; Scopelliti, Rosario (2008-01-20)
N,N-Bis(diphenylphosphino)ethylaniline compounds, [Ph2P](2)N-C6H4-C2H5, with ethyl groups at the ortho- and para-positions have been synthesized. Oxidation of the aminophosphines with hydrogen peroxide, elemental sulfur and selenium gave the corresponding oxides, sulfides and selenides [Ph2P(E)](2)N-C6H4-C2H5 (E = O, S, Se). Complexes [MCl2{(Ph2P)(2)N-C6H4-(C2H5)}] (M = Pd, Pt) and [Cu{(Ph2P)(2)N-C6H4-C2H5)(2)]PF6 were obtained by the reaction of NN-bis(diphenylphosphino)ethylaniline with [MCl2(COD)] (M = P...
Citation Formats
N. Saracoglu, A. Menzek, S. Sayan, U. Salzner, and M. Balcı, “Pyramidalized double bonds containing endoperoxide linkages: Photooxygenation of dimethyl cis-3,8-dihydroheptalene-3,8-dicarboxylate,” JOURNAL OF ORGANIC CHEMISTRY, pp. 6670–6676, 1999, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/57801.