Molecular structures of regioisomeric 7‐arylidene hexahydroindazoles from 1H NMR spectra |
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Authors: | Nikolay S Pivnenko Alexander V Turov Vladimir V Abakumov Lidiya A Kutulya Svetlana V Shishkina Oleg V Shishkin |
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Institution: | 1. STC “Institute for Single Crystals”, National Academy of Sciences of Ukraine, 60 Lenin Ave, Kharkov, 61001 Ukraine;2. T.G. Shevchenko Kiev National University, Vladimirskaya St. 4, Kiev, 01033 Ukraine |
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Abstract: | The structural characterization of two regioisomeric products of the interaction of 2,6‐bis‐(4‐methoxybenzylidene)‐3R‐methylcyclohexanone with methyl hydrazine was achieved using 1H NMR spectral data, including chemical shifts, coupling constants and results of COSY and nuclear overhauser effect (NOE) experiments. Configurations of the new chiral centers in the (3S,3aR,6R,7E)‐7‐(4‐methoxybenzylidene)‐3,4,5,7‐hexahydro‐3‐(4‐methoxyphenyl)‐2,6‐dimethyl‐ and 2,4‐dimethyl‐2H‐indazoles were assigned on the basis of experimental data combined with molecular modeling by the density functional theory (DFT) method. The distinction in the helical twisting power of studied compounds under addition to a nematic liquid crystal is discussed on the basis of peculiarities of the molecular structures. Copyright © 2009 John Wiley & Sons, Ltd. |
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Keywords: | NMR 1H NMR COSY NOESY stereochemistry conformation chiral (3S 3aR 6R 7E)‐7‐(4‐methoxybenzylidene)‐3 4 5 7‐hexahydro‐3‐(4‐methoxyphenyl)‐2 6‐dimethyl‐ and 2 4‐dimethyl‐2H‐indazoles |
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