Synthesis and Radical Induced Ring Opening Reaction of 1-Trialkylsilyl-2-vinylcyclopropanes

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 ring opening reaction of these cyclopropanes were examined. 1-Dimethylphenylsilyl-2-vinylcyclopropane or 3-methyl-1-trialkylsilyl-2-vinylcyclopropane provided the corresponding homoallylic silane exclusively upon treatment with PhSH, Ph3SnH, n-Bu3SnH, or n-C6F13I. On the other hand, 2-phenyl-1-trimethylsilyl-3-vinylcyclopropane or 2-acetyl-1-trimethylsilyl-3-vinylcyclopropane gave allylic silane selectively.