When, how and why does sodium metal react with cycloalkenes, cycloalkadienes, cycloalkatrienes? I've been searching for the conditions necessary for the reaction of sodium (Na) metal with cycloalkenes, cyclo-di-alkenes, cyclo-tri-alkenes all over the internet but I cannot find a proper answer. Can someone explain to me the necessary conditions?

For example why does sodium metal react with cyclopentadiene but not with cycloheptatriene?
The negatively charged particles are conjugate bases of respective compounds, which (reactants) acts due to presence of active methylene group. Depends on the stabitily of conjugate base the reaction goes forward.