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Treatment of trimethylchlorosilan with a keton enolate usually leads to a silyl enol ether(O- silylated product) rather than the C- Silylated keton. Since bis - silylated Ketones could uot be prepared by this procedure we decided to prepare the enolates of compouuds by treating alkyllithium and Gringnard reagents with bis - (trimethy sily) ketene, availble from lithio tert - butyl bis - (trimethy sily) acetate.
Bis - (trimethylsily) ketene was reacted with methyl lithium, n - butyllithum aud tertbutyllithium at room temprerature to give the corresponding a. a - bis - (trimethylsilyl) Ketone enolate.
a, a - bis (trimethylsily) Ketones were obtained in 75-85% yield by quenching the reaction mixtures with dilute acetic acid or H20.
Bis - (trimethylsilyl) ketene was reacted with methyl magnesium bromide. ethyl magnesium bromide, phenyl magnesium bromide and other Grignard reagents at a wide varity conditions but unfortunately none of the expected products were obtained.