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Unusual effects of steric hindrances in NMR spectra of o,o′-dialkylsubstituted benzylidene dichlorides

✍ Scribed by A.P. Yakubov; D.V. Tsyganov; L.I. Belen'kii; V.S. Bogdanov; B.I. Ugrak; M.M. Krayushkin

Publisher
Elsevier Science
Year
1991
Tongue
French
Weight
511 KB
Volume
47
Category
Article
ISSN
0040-4020

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✦ Synopsis

It has been found that steric hindrances of the CRC12 group rotation around CAr -CHC12 bond in o,o'-dialkylsubstituted benzylidene dichlorides call forth a non-equivalence of the alkyls in positions 2 and 6. The non-equivalence displays in 'H and 13C EMR spectra at room temperature and at -20 "C. At the latter temperature, the spectra of 2,4,6-trimethyl-3-chloromethylbenzylidene dichloride and bis(dichloromethyl)mesitylene indicate the presence of two conformations, the assignment of signals having been accomplished for each of them.

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