The reduction of acetals derived from formaldehyde, acetaldehyde, acetone, and diethyl ketone to the corresponding ethers with trichlorosilane under y irradiation has been studied. An acetal reacts at first with chlorosilane to give an a-chloro ether, which is in turn reduced with the silicon hydride under y irradiation. The present study, especially the reduction of mixed acetal containing a triethylsilyl group, makes clear the reduction sequence of an ...