Silicon-containing heterocyclic compounds I. Preparation and reactions of 1,1,2,2,-tetramethyl-1,2-disilacycloalkanes, from disilacyclopentane to disilacyclooctane

Article abstract of DOI:10.1016/S0022-328X(00)92403-3

Four 1,2-disilacycloalkanes of the formula Me₂SiSiMe₂-(CH₂)_n, where n equals 3, 4, 5 and 6, have been prepared by two methods: one involves reaction of ClMe₂SiSiMe₂Cl with BrMg(CH₂)_nMgBr, the other comprises sodium/potassium condensation of ClMe₂Si(CH₂)_nSiMe₂Cl. It has been found that both the disilacyclopentane and -hexane exclusively undergo cleavage of the silicon-silicon bond when treated with concentrated sulfuric acid, whereas the disilacycloheptane gives several products in which the silicon-silicon bond has not been cleaved. The disilacyclopentane undergoes cleavage of the silicon-silicon bond when heated with 0.6 N sodium ethoxide in ethanol at 90°, while the disilacyclohexane is quite stable under the same conditions.