On the basis of PMR decoupling experiments and thermal decomposition studies, the reaction of the cyclooctatetraenyl dianion and chlorotrimethylsilane produces 5,8-bis(trimethylsilyl)-l,3,6-cyclooctatriene, in contrast to a previous report which suggested 7,8-bis(trimethylsilyl)-l,3,5-cyclooctatriene. The product is stable at room temperature in vacuo but undergoes decomposition (isomerization) reactions at higher temperatures or in contact with air.