A variety of trialkylsilylvinylcyclopropanes were prepared by two different routes: (a) Cyclopropanation of 1-alkenylsilanes and (b) the reactions of 1-bromocyclopropyllithium with trimethylsilyl chloride. Radical induced ringopeningreaction of these cyclopropanes were examined. 1-Dimethylphenylsilyl-2-vinylcyclopropane or 3-methyl-1-trialkylsilyl-2-vinylcyclopropane provided the corresponding homoallylic