| Abstract
| - High-temperature bromination of 10-bromotricyclo[6.3.1.02,7]dodeca-2,4,6,9-tetraene (8) resultedmainly in the formation of two isomeric tribromides (16 and 17) whose dehydrobromination withDBU afforded the corresponding 9,10-dibromotricyclo [6.3.1.02,7] dodeca-2,4,6,9-tetraene (14).Treatment of 14 with tert-butyllithium in THF at −78 °C produces the strained bicyclic alkyne(10) which is trapped by 1,3-diphenylisobenzofuran to give two isomeric cycloadducts 12a and 12b.The adducts 12a and 12b were found to readily rearrange to the isomeric ketones 19a and 19bupon chromatography. Upon treatment with potassium tert-butoxide, the adducts 12a and 12bundergo base-catalyzed double bond isomerization to give four products 20−23. Furthermore,reaction of 14 with one and two mole of potassium tert-butoxide has been studied and the mechanismof the product formation is discussed with regard to either an allene or alkyne as a possibleintermediate.
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