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
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 determined butterfly angles. Furthermore, it has been shown that a cyclopropyl group fused to [2.2.2] system decreases significantly the degree of the pyramidalization which is attributed to the steric interactions between the cyclopropyl group and ethano bridge of the norbornene systems. Due to the instability of the bicyclic endoperoxides, their X-ray analysis could not be carried out. DFT calculations on model compounds showed increased bending in the case of the product obtained by the addition of singlet oxygen to endo-2,3,4,7tetrahydro-1H-1,4-methanobenzocycloheptene-7-carboxylic acid ethyl ester.


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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...
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Chiral Baeyer-Villiger (BV) oxidation of cyclic ketones allows rapid access to asymmetric lactones as valuable intermediates in organic chemistry and frequently encountered precursors in enantioselective synthesis. In the first part, BV oxidation of functionalized ketones, especially cyclic -hydroxy and acetoxy ketones is described which could be a straightforward route to the -hydroxy lactones and -hydroxyalkanoic acid derivatives. The -acetoxylation of indanone, tetralone and chromanone derivatives by usi...
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Zeytinci, Serhat; Doğan, Özdemir; Department of Chemistry (2006)
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Çakır, Esen; Tanyeli, Cihangir; Department of Chemistry (2007)
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Keskin, Eda; Tanyeli, Cihangir; Department of Chemistry (2007)
Aminoalcohols are very important compounds used in various asymmetric transformations as chiral ligands or chiral auxiliaries. In this thesis, four novel heterocyclic amine substituted chiral 1,4-aminoalcohols were synthesized. In the synthetic strategy, amide esters were synthesized from (2S, 3R)-3-methoxycarbonylbicyclo[2.2.1]hept-5-ene-2-carboxylic acid by DCC coupling method. Subsequent reduction of these amide esters lead to target 1,4-aminoalcohols. The activities of these novel chiral 1,4-aminoalcoho...
Citation Formats
N. Saracoglu, O. Talaz, A. Azizoglu, W. Watson, and M. Balcı, “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,” JOURNAL OF ORGANIC CHEMISTRY, pp. 5403–5408, 2005, Accessed: 00, 2020. [Online]. Available: