Ketenesilyl acetals

Conjugate addition of ketenesilyl acetals to a,P-unsaturated carbonyl compounds (Mukaiyama-Michael reaction) with Li Lewis acid has been widely investigated. When sterically less hindered ketenesilyl acetals are utilized, the reaction proceeded smoothly, even in catalytic systems (with LiCo(B9C2Hn)2 in CICH2CH2CI or LiCl04 in CH2CI2). On the other hand, in the case of more hindered ketenesilyl acetals, high concentration of LPDE is necessary to promote the reaction... 

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