| Autor: |
Brecknell, Douglas J., Carman, Raymond M., Edwards, Ross A., Hansford, Karl A., Karoli, Tomislav, Robinson, Ward T. |
| Zdroj: |
Australian Journal of Chemistry; 1997, Vol. 50 Issue: 7 p689-700, 12p |
| Abstrakt: |
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 Avalue for a bromomethyl group in this system is then similar to that of an unsubstituted methyl group. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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