Hasel, Winnfried; Schnick, Wolfgang; Jansen, Martin; Hoffmann, H. M. R.
Highly alkylated cyclohexanes. X-Ray crystal structures, force-field calculations, and conformations of cis/trans-1,4-disubstituted cyclohexane isomers.
In: Chemische Berichte, Vol. 121, No. 8: pp. 1469-1474
The structures of mesylated cis- and trans-tetramethylshisool cis- 2 and trans-2 have been elucidated by single-crystal X-ray techniques. In cis-2 the isopropenyl group adopts an axial position in the crystal, and the structural data obtained are in good agreement with those from force-field calculations. In trans-2 the two rotamers arising from rotation of the isopropenyl group were assigned by NOE measurements. Comparison of the spectroscopic data with those of other tetramethyllimonene derivatives showed that these can be classified into compounds with preferred equatorial and preferred axial position of the isopropenyl group.