Improved Solvent-Free Synthesis and Structure Elucidation of (E)- and (Z)-4-(Arylmethylene)-3-isochromanones

Analysis of vibrational spectra of some new E- and Z-4-arylidene-3-isochromanones

“…The title compounds have been synthesized according to a new, one-step method by base-catalyzed Knoevenagel condensation conducted under solvent-free conditions [5]. The reaction is usually stereospecific, providing either the E or the Z isomer (Scheme 1), due to intramolecular steric/electronic interactions reflected in increased stability of one of the isomers.…”

“…Depending on the aromatic aldehyde, it may occasionally yield a mixture of the two isomers that can be separated by means of column chromatography. Seventeen different aryl derivatives have been prepared, six of which were obtained as mixtures of E and Z isomers whose relative proportions were determined by 1 H and 13 C NMR spectroscopy [5].…”

“…This contribution deals with the structure and vibrational spectra of the 2V-pyrrolyl and 2V-nitrophenyl derivatives. 12) were prepared as described previously [5]. The synthesis of IK-6 yielded pure Z isomers; recrystallization from methanol gave dark red crystals (m.p.…”

Design, synthesis, biological evaluation, and molecular dynamics of novel cholinesterase inhibitors as anti‐Alzheimer's agents

“…The structures of all the newly synthesized compounds were characterized by IR, 1 H NMR, 13 C NMR spectroscopies, and CHN analyses. It is well‐known that the geometry of compounds is affected by thermodynamically controlled reactions . So at room temperature and even by rising temperature up to 80°C, E isomer is obtained, while in the presence of hυ irradiation conditions, Z isomer is formed.…”

“…So at room temperature and even by rising temperature up to 80°C, E isomer is obtained, while in the presence of hυ irradiation conditions, Z isomer is formed. Therefore, the molecular configuration of all of the compounds that have been obtained at room temperature is assigned as E configuration …”