Study of the reaction of 1,1-bis(trimethylsilyl)-2-phenylethylene with some acyl chlorides in the presence of AlCl3

1,1-Bis(trimethylsilyl)-2-phenylethylene (1), which has been synthesized from the Peterson reaction between (Me3Si)3CLi and benzaldehyde, reacts with various acyl chlorides (RCOCl, R = Me, Et, iso-Pr, n-Bu, iso-Bu, iso-C5H11, PhCH2, PhCH2CH2) in the presence of AlCl3 to give α-silyl-α,β-unsaturated enones 3a–3h with high E stereoselectivity along with trans-α,β-unsaturated ketones 4a–4h. The enones 3 can be partially converted into the ketones 4 with an excess of AlCl3. Reaction of 1 with RCOCl, (R = Ph, CH3CH=CH) afforded only the ketones 4. Yields were dependent on time and the amounts of AlCl3 used.