and 1,7-bis(acylsilanes) have been prepared using a strategy of substitution of dihalo derivatives with a synthetic equivalent of the trialkylsilylcarbonyl anion. These bis(acylsilanes) could easily be converted, under Lewis acid activation, into cis-β-hydroxyacylsilanes or the corresponding α,β-unsaturated derivatives, by means of a completely stereoselective intramolecular aldolreaction.