Abstract The preparation of the first silacyclopropanes, all derivatives of 7, 7-dimethyl-7- siladispiro [2.0. 2.1] heptane, by magnesium-induced ring closure reactions of 1, 3-dihalides, is described. Mass spectral and 1 H, 13 C and 29 Si NMR spectral data, as well as the unusually high chemical reactivity of these compounds support the assigned silacyclopropane structures.
![1',1'-dimethyl-dispiro[bicyclo[4.1.0]heptane-7,2'-silirane-3',7''-bicyclo[4.1.0]heptane] Structure](https://image.chemsrc.com/caspic/219/42732-69-4.png)
![[7-(7-bicyclo[4.1.0]heptanyl)-7-bicyclo[4.1.0]heptanyl]methoxy-dimethylsilane Structure](https://image.chemsrc.com/caspic/487/40193-83-7.png)