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Empirical force field calculations VII. Rotation of the tert-butyl groups on the chair conformers of tert-butylcyclohexane, 9-tert-butylbicyclo[3.3.1]nonane and cis-1,2-di-tert-butylcyclohexane

✍ Scribed by J. M. A. Baas; B. van de Graaf; A. van Veen; B. M. Wepster


Publisher
Elsevier Science
Year
2010
Tongue
English
Weight
444 KB
Volume
99
Category
Article
ISSN
0165-0513

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✦ Synopsis


Abstract

Empirical force field calculations indicate the existence of two chair conformers of cis‐1,2‐di‐tert‐butylcyclohexane. The energy difference amounts to 4.82 kJ mol^−1^ using the Engler force field. Reaction paths for the interconversion of these conformers have been explored by means of the forced rotation of the tert‐butyl groups. Six transition states have been found in a complicated scheme. The barriers to rotation of both tert‐butyl groups are compared with those calculated for an axial and an equatorial tert‐butyl group on the chair conformation of cyclohexane and on position 9 of bicycle[3.3.1]nonane.