Bredt’s Rule

Trans cycloalkenes are not stable unless there are at least 8 carbon atoms in the ring. Bredt’s rule states that a bridged bicyclic compound cannot have a double bond at the bridgehead position unless one of the rings contains at least 8 carbon atoms.

bond is at bridgehead,

system in not bridged.

bridgehead and ring contains

only 6 carbons.

Trans cycloalkenes are not stable unless there are at least 8 carbon atoms in the ring. Bredt’s rule states that a bridged bicyclic compound cannot have a double bond at the bridgehead position unless one of the rings contains at least 8 carbon atoms.