INTERCONVERSIONS AMONG ALPHA-(TRIMETHYLSILYL) ALKOXIDES, ALPHA-TRIMETHYLSILOXY CARBANIONS, AND CARBONYL-COMPOUNDS ACCOMPANIED BY THE TRIMETHYLSILYL ANION

The possible existence of an unusual cycle was investigated, which inv olved an equilibrium among alpha-silylalkoxides, alpha-siloxy carbanio ns, and carbonyl compounds accompanied by -SiR3. This postulation was supported by the product distributions of a series of control reaction s: the C-deprotonation of 3-methoxybenzyl trimethylsilyl ether, the 0- deprotonation of 3-methoxy-alpha-(trimethylsilyl)benzyl alcohol, and t he 1,2-addition of 3-methoxybenzaldehyde with LiSiMe3. Consistent with this postulation were results from the reaction of 3-methoxybenzyl al cohol with KH and Me3SiSiMe3, giving 3-methoxybenzaldehyde (20% yield) , and the reaction of alpha-clopropylbenzyl trimethylsilyl ether with LiSiMe3, affording cyclopropyl phenyl ketone (90% yield).