Base-promoted acyloin rearrangement of 1,8-di-tert-butyldimethylsilyloxybicyclo[2.2.2]oct-5-en-2-ones

Treatment of 1,8-di-tert-butyldimethylsilyloxybicyclo[2.2.2]oct-5-en-2-ones having an electron-withdrawing group such as a nitro, formyl, cyano, and imido group at C-7 with a strong base (potassium hydride, or potassium bistrimethylsilylamide, etc.), resulted in an acyloin rearrangement reaction accompanied by retention of two silyloxy groups to afford 1,8-disilyloxybicyclo[3.2.1]oct-3-en-2-ones.