Process for isolating cyclopentane and/or cyclopentene

Cyclopentane and/or cyclopentene and, if desired, isopentane can be obtained by distillative separation from a pre-benzene fraction or a C5 fraction which has in each case being partially hydrogenated to remove acetylene compounds and diolefins, whereina) in a first fractional distillation, low boilers are removed as first top product and, eitherb1) the first bottom product is fed to a second fractional distillation and there cyclopentene is taken off as second top product and cyclopentane and higher-boiling hydrocarbons are taken off as second bottom product and this second bottom product is separated into cyclopentene and higher boilers in a third fractional distillation, orb2) the first bottom product is subjected to a catalytic hydrogenation and subsequently, in a fractional distillation, separated into cyclopentane as top product and higher boilers as bottom product, orb3) the first bottom product is subjected to a fractional distillation to separate off the relatively high boilers as bottom product and the top product is subjected to a catalytic hydrogenation to form cyclopentene.