The molecular structure of conformationally stable 1-(p-bromophenyl)-4-t-butyl-1-methyl-1-silacyclohexane was determined by an X-ray diffraction study. Stereochemical as well as kinetic studies on halodesilylation of both cis- and trans-4-t-butyl-1-nethyl-1-phenyl-1-silacyclohexanes are described.