Synthese nouvelle d'allylcetones par voie organosilicique

In the presence of a Lewis acid (AlCl₃, InCl₃, GaCl₃), acyl chlorides react with allyltrimethylsilane to give the corresponding allyl ketones, CH₂CHCH₂COR, in good yields.Substituted allylsilanes, synthesized by 1,4-disilylation of conjugated dienes, give a similar reaction. The electrophilic substitution of SiMe₃ by a COR group occurs with allylic rearrangement and therefore silylated β,γ-ethylenic ketones,

, are obtained. In most cases the allylic ketones prepared isomerize easily to the corresponding conjugated ketones; ketones having the formula CH₂CHCH₂COR lead uniquely to the trans-,propenylketones, MeCHCHCOR.