Electrolytic reduction of dichloromethylphenyl-, dichlorodiphenyl-, dichlorodi-o-tolyl-, and dichlorodi-p-tolylsilanes in the presence of 2, 3-dimethylbutadiene afforded 1-methyl-1- phenyl-, 1, 1-diphenyl-, 1, 1-di-o-tolyl-, and 1, 1-di-p-tolyl-3, 4-dimethyl-1-silacyclopent-3- ene, respectively, while the similar reaction of chloromethyldiphenylsilane with 2, 3- dimethylbutadiene afforded 1-(methyldiphenylsilyl)-and 1, 4-bis (methyldiphenylsilyl)-2, 3- ...