Single crystal structure and molecular dynamics analysis of a myo-inositol derivative

The crystal structure of 5-O-tert-butyldimethylsilyl-3,4-O-carbonyl-1,2-O-cyclohexylidene-2-oxo-3-oxa-4-bornanylcarbonyl-D-myo-inositol has been studied by single-crystal X-ray diffraction at both room temperature and 173 K. At room temperature, the tert-butyldimethylsilyl group exhibits dynamical disorder. A molecular dynamics simulation was used to model the disorder and this indicates that the group librates between two stable conformations in the crystal. Approximate relative energies of the different forms and energy barriers for the transition were obtained by empirical force field methods. Calculations of the thermal motion of the atoms are in good qualitative, but fair to poor quantitative agreement with the X-ray data.