Yazar "Demircan A." seçeneğine göre listele

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  • Küçük Resim Yok
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    (3aR*,6S*,7aR*)-7a-Chloro-6-methyl-2-(4-methyl-phenyl- sulfon-yl)-2,3,3a,6,7,7a-hexa-hydro-3a,6-ep-oxy-1H-isoindole
    (2012) Temel E.; Demircan A.; Beyazova G.; Büyükgüngör O.
    In the title compound, C16H18ClNO3S, the six-membered ring has a boat conformation. The two five-membered rings with the bridging O atom adopt envelope conformations, whereas the N-containing five-membered ring adopts a twisted conformation. In the crystal, C-H?O hydrogen bonds link the mol-ecules into a three-dimensional network.
  • Küçük Resim Yok
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    (3aR,6S,7aR)-7a-Chloro-2-[(4-nitrophenyl)sulfonyl]-1,2,3,6,7, 7a-hexahydro-3a,6-epoxyisoindole
    (2013) Temel E.; Demircan A.; Kandemir M.K.; Çolak M.; Büyükgüngör O.
    In the title compound, C14H13ClN2O5S, the chlorine-substituted tetrahydrofuran ring adopts a twist conformation and the other tetrahydrofuran ring an envelope conformation with the O atom as the flap. The pyrrolidine ring adopts a twist conformation. In the crystal, C - H?O hydrogen bonds link the molecules into zigzag chains running along the b-axis direction.
  • Küçük Resim Yok
    Öğe
    (3aR,6S,7aR)-7a-Chloro-6-methyl-2-(4-nitrophenylsulfonyl)-1,2,3,6,7, 7a-hexahydro-3a,6-epoxyisoindole
    (2013) Demircan A.; Temel E.; Kandemir M.K.; Çolak M.; Büyükgüngör O.
    In the title compound, C15H15ClN2O 5S, the tetrahydrofuran ring adopts an envelope conformation with the O atom as the flap. The pyrrolidine ring adopts an envelope conformation with the chlorine-substituted C atom as the flap. In the crystal, two types of C - H?O hydrogen bonds generate R22(20) and R 44(26) rings, with adjacent rings running parallel to ac plane. Further C - H?O hydrogen bonds form a C(6) chain, linking the molecules in the b-axis direction.
  • Küçük Resim Yok
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    Ab initio studies on 5-Bromo-10-oxa-3-thiatricyclo[5.2.1.0 1,5]-Dec-8-ene3,3-dioxide
    (2007) Arslan H.; Demircan A.
    5-Bromo-10-oxa-3-thiatricyclo[5.2.1.01,5]-dec-8-ene 3,3-dioxide (BOTCDO) was synthesized from the reaction between 2-(2- bromoallylsulfanylmethyl)-furan and m-chloroperbenzoic acid in dichloromethane. The molecular structure and vibrational frequencies of BOTCDO in the ground state have been investigated with ab initio (HF) and density functional theory methods (B3LYP, B3PW91 and MPW1PW91) implementing the standard 6-31G(d) basis set. The optimized geometric bond lengths and bond angles obtained by using HF and DFT methods show the best agreement with the experimental data. Comparison of the observed fundamental vibrational frequencies of title compound and calculated results by HF and DFT methods indicate that MPW1PW91 is superior to the scaled HF approach for molecular problems. Optimal uniform scaling factors calculated for the title compound are 0.8920, 0.9553, 0.9518 and 0.9452 for HF, B3LYP, B3PW91 and MPW1PW91 methods, respectively.
  • Küçük Resim Yok
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    Thermal intramolecular Diels-Alder reaction of furan; synthesis of nitrogen tetracycles, isobenzofuran and isobenzothiophene
    (2007) Karaarslan M.; Gokturk E.; Demircan A.
    Thermal intramolecular Diels-Alder (IMDA) reaction of furan cored compounds has been further investigated; a series of key precursors to the IMDA reaction of furan diene (9a-c) have been prepared via facile alkylation and protection. While the cycloaddition process for (10a-c) was afforded in hot toluene, a commercial microwave (2450 MHz) was used for the synthesis of (12a-b). Treatment of fused oxy- and thio-heterotricycles (12a-b) with borontrifluoride-etherate in dichloromethane at -78°C cleaved epoxy bridge and concomitant aromatisation gave the isobenzo-furan and thiophene (13a-b) in 72-76% yields respectively.