Abstract A five-carbon ring-expansion reaction from a cyclohexane derivative fitted with a 3- hydroxy-2-silyloxyprop-1-en-1-yl unit in lieu of one of the C= C double bonds in the Cope rearrangement was studied to synthesize cycloundecanone derivatives. It was found that (E)- triethylsilyl enol ether is necessary for the reaction. The trans-isomer with respect to the cyclohexane ring afforded (2E, 8E)-cycloundeca-2, 8-dien-1-one, while its cis-isomer ...
