As nouns the difference between cyclopropane and spirocyclopropane

is that cyclopropane is the simplest alicyclic hydrocarbon, C₃H₆, an inflammable gas, sometimes used as an anaesthetic while spirocyclopropane is a divalent radical in which a cyclopropane ring is fused to another ring at a single carbon atom, the two rings being more-or-less at right angles to one another.