Hydrosilylation of cyclohexene and isopropylidenecyclohexane with chloro(methyl)silanes Me3−n SiHCln (n = 1–3) gives rise to cyclohexyl- and chloro(2-cyclohexylpropyl)methylsilanes. Hydrosilylation of 1-methylcyclohexene with chlorodimethylsilane (n = 1) occurs anomalously and involves double-bond migration to form a mixture of seven compounds: the cis and trans isomers of 2-, 3-, 4-chlorodimethyl(methylcyclohexyl)silanes and chlorodimethyl(cyclohexylmethyl)silane. Chlorodimethylsilane (n = 2) adds to 1-methylcyclohexene to form a mixture of the cis and trans isomers of dichloro(methyl)(2-methylcyclohexyl)silane and dichloro(cyclohexylmethyl)methylsilane. With trichlorosilane (n = 3), no other products than trichloro(cyclohexylmethyl)silane are formed. The hydrosilylation products were reacted with ethynylmagnesium bromide to synthesize the corresponding ethynyl derivatives.