Reaction of 1,3-Disilacyclopentanes with MeMgCl

Reaction of 3 with 2 mole equivalents of MeMgCl in Et20 at 20 °C generates 355  

At temperatures exceeding 140 °C, a ring cleavage occurs via P-elimination producing the linear vinyl compound 357. 

Obviously Si-methylation begins on the SiCl2 group not adjacent to the CCI2 group. 

The reaction of 3 with 6 mole equivalents of MeMgCI also produces methylation of Si atom 3, and yet the main products of the reaction arise from ring cleavage occurring by means of p-elimination. An example of this is the formation of H2C=CCl-SiMeCl-CH2-SiMe2Cl [148]. 

Cl2C = CCl-SiMe -CCl -SiMej cCl-SiCl -CMeCI-SiMe Cl 361 362 66% 11% 

---