Molecular dynamics of (Z)-1-(2-hydroxy-5-methyl-3-nitrophenyl)ethanone oxime and (E)-2-hydroxy-5-methylacetophenone thiosemicarbazone in solution studied by NMR spectroscopy

Synthesis of a new 1,2,3,4,5-pentasubstituted cyclohexanol and determining its stereochemistry by NMR spectroscopy and quantum-chemical calculations

The presence of substituents in cyclohexane can influence to the ratio of conformers; for some cases, the boat form is preferable. The new six-membered cyclohexanol derivative 2 has been obtained by the synthesis of (E)-1-(bromophenyl)-3-phenylpropen-2-one (1). The NMR and quantum-chemical conformational analysis for the 2 have carried out, and its possible mechanism of formation was given. Copyright © 2015 John Wiley & Sons, Ltd.

New synthesis on the basis 2-allyloxy chalcone and NMR studies its some derivatives

Synthesis and NMR investigations of cyclohexenone, flavanone, isoxazol and indazole derivatives of (2E)-3-[2-(allyloxy)-5-bromophenyl]-1-(2-hydroxy-5-methylphenyl)-2-propen-1-one (I, chalcone) have been carried out. The results confirm the formation of O-H•••O type intramolecular hydrogen bond and intramolecular cyclization in the (2E)-3-[2-(allyloxy)-5-bromophenyl]-1-(2-hydroxy-5-methylphenyl)-2-propen-1-one (I), the presence of conformational and keto-enol tautomeric transitions in the 6-acetyl-5-[2-(allyloxy)-5-bromophenyl]-3-(2-hydroxy-5-methylphenyl)-2-cyclohexen-1-one (II), conformational transitions in the 2-{4-[2-(allyloxy)-5-bromophenyl]-3-methyl-4.5-dihydro-1.2-benzisoxazol-6-yl}-4-methylphenol (III) and 2-{4-[2-(allyloxy)-5-bromophenyl]-3-methyl-4.5-dihydro-1H-indazol-6-yl}-4-methylphenol (IV). The conformational and keto-enol tautomerism in the investigated compounds have been also confirmed by chemical methods.

Molecular dynamics of 6-methyl-2-phenyl-2,3-dihydro-4H-chromen-4-one and 6-methyl-2-(4-nitrophenyl)-2,3-dihydro-4H-chromen-4-one (flavanone) derivatives in a solution studied by NMR spectroscopy

Molecular dynamics of benzoxazepin, oxime, pyrazole, and thiosemicarbazone derivatives of some flavanones have been investigated in a solution using NMR. The results confirm the formation of different O-H···O, O-H···N, N···H-N type intramolecular hydrogen bonds in the pyrazole and oxime molecules. The rotational barrier energy and energy of intramolecular hydrogen bonds have been determined.