
%0 Journal Article
%A Brecknell, Douglas J. 
%A Carman, Raymond M. 
%A Edwards, Ross A. 
%A Hansford, Karl A. 
%A Karoli, Tomislav 
%A Robinson, Ward T. 
%T Halogenated Terpenoids. XXIX The 1-Bromo 1-Bromomethyl Cyclohexyl System
%J Australian Journal of Chemistry
%D 1997/09/05
%V 50
%N 7
%P 689-700
%K 
%R https://doi.org/10.1071/C96188
%U https://www.publish.csiro.au/paper/C96188 
%X Bromination of methylene groups exocyclic to cyclohexyl systems normally affords two isomeric products; the axial 1-bromo equatorial 1-bromomethyl compound and the axial 1-bromomethyl equatorial 1-bromo derivative. Free energy differences between these two isomers, and the conformations adopted by the axial 1-bromomethyl group, have been explored by n.m.r. spectroscopy, by X-ray crystallography and by MM3 calculations. Evidence is presented to show that the ax-bromomethyl group exists primarily as those rotamers which site the bromine atom synclinal to the vicinal bromine. The A value for a bromomethyl group in this system is then similar to that of an unsubstituted methyl group. 
