4484-53-1Relevant academic research and scientific papers
Conformations of E-2-phenyl-3(2′-furyl)propenoic acid and its methyl ester in various solvents - An NMR study
Forgó,Felf?ldi,Pálinkó
, p. 273 - 276 (2007/10/03)
The conformations of E-2-phenyl-3(2′-furyl)propenoic acid and its methyl ester were investigated by NMR spectroscopy. Applying various solvents (methanol, chloroform and dimethyl sulfoxide) the possible conformers in solutions were studied by two-dimensional NOESY measurements. Irrespective to the solvents and whether the investigated moiety was the ester or the acid dimer, no conformational preferences could be identified experimentally.
Metal Ion Effects in Wittig Reactions: A General Hypothesis for the Mechanism of the Wittig Reaction
Ward, William J.,McEven, William E.
, p. 493 - 500 (2007/10/02)
To evaluate better the effects of N2p-P(IV) through-space interactions in Wittig reactions, a thorough study of metal ion effects in Wittig reactions lacking such interactions has been completed.As in the case of Wittig reactions with stabilized ylides, it has been determined that, with a moderated ylide, the stereochemistry (E:Z ratio) of alkene formation with an aldehyde is determined at the point that a new carbon-carbon bond has been formed to give a betaine or an oxaphosphetane intermediate.The observations that in most cases where lithium ion is present, theproduct mixture is enriched with the Z alkene, while when sodium or potassium ions are present, the E isomer predominates, are deemed to support the concept that a spin-paired diradical is formed as an unstable intermediate when sodium or potassium ions are present but that an ionic reaction occurs when lithium ions are present.The evidence that has been accumulated suggests that the reactions studied here (involving aromatic, heterocyclic, and aliphatic aldehydes and benzylidenediphenylmethylphosphorane or the preformed betaines, in THF at -78 deg C) occur under kinetic control and without any significant degree of equilibration or Wittig reversal.
SYNTHESIS OF BENZOFURO- AND BENZOTHIENOPHENANTHRIDONES BY TWOFOLD PHOTOCHEMICAL DEHYDROCYCLIZATION REACTION
Karminski-Zamola, G.,Bajic, M.
, p. 1325 - 1334 (2007/10/02)
Four new N-(p-chlorophenyl)carboxamides 1 - 4 of 9-phenanthrene-, 5-naphthofuran-, and 5-naphtho- and 4-naphthothiophenecarboxylic acids have been synthesized.All carboxanilides were exposed to UV oxidative irradiation in methanolic solution.In the case of 2 and 3 corresponding benzo-furophenanthridin-10(9H)-one 5 and benzo-thienophenanthridin-10(9H)-one 6 are isolated.
Structural Effects of the Acidity of E-α-Phenyl-β-arylacrilic Acids
Maccarone, Emanuele,Mamo, Antonino,Perrini, Giancarlo,Torre, Michele
, p. 395 - 398 (2007/10/02)
The dissociation equilibrium constants of some E-α-phenyl-β-arylacrilic acids (Ar=2-pyridyl, 3-pyridyl, 4-pyridyl, 1-naphthyl, 2-naphthyl, anthracen-9-yl) have been measured in 80percent aqeous 2-methoxyethanol at 25 deg C., The pKa values of these acids, together with those of p-substituted phenyl, 2-furyl, 2-thienyl and selenophen-2-yl derivitives, have been rationalized by an equation involving separate contributions of polar, conjugative and steric effects of heterocycles.The pKa values of some E-α-phenyl-β-alkylacrilic acids (alk=methyl; ethyl; n-propyl; i-propyl; n-butyl; i-butyl) are also reported.
