DO(METHOXYDIMETHYLSILYL)BIS(TRIMETHYLSILYL)METHANE - A REAGENT FOR THE PREPARATION OF NOVEL ORGANOMETALLIC COMPOUNDS - CRYSTAL-STRUCTURE OFMG(C(SIME(3))(2)(SIME(2)OME))(2) AND MGI2(OET(2))(2)

The alkyl chloride R(2)(HMe(2)Si)CCl (R = SiMe(3)) reacted with ICl to give the iodide R(2)(ClMe(2)Si)CI, which with MeOH gave R(2)((MeOMe(2 )Si)CI. This reacted with Mg in Et(2)O to give MgI2(OEt(2))(2) (which was isolated and structurally characterised) and the chelated dialkylm agnesium Mg{C(SiMe(3))(2)(SiMe(2)OMe)}(2), apparently following initia l formation of the Grignard reagent MeOSiMe(2)CR(2)MgI. The latter com pound was isolated from the products of the reaction between the iodid e R(2)(MeOMe(2)Si)CI and Mg in toluene. The lithium compound MeOSiMe(2 )CR(2)Li was made by treatment of the chloride R(2)(MeOMe(2)Si)(2)CCl with Bull in THF and the chelated structure was confirmed by an X-ray study.