Preferred Label : Bredt's rule;
IUPAC definition : A double bond cannot be placed with one terminus at the bridgehead of a bridged ring
system unless the rings are large enough to accommodate the double bond without excessive
strain. For example, while bicyclo[2.2.1]hept-1-ene is only capable of existence as
a transient, its higher homologues having a double bond at the bridgehead position
have been isolated: e.g.;
Origin ID : B00732;
See also
A double bond cannot be placed with one terminus at the bridgehead of a bridged ring
system unless the rings are large enough to accommodate the double bond without excessive
strain. For example, while bicyclo[2.2.1]hept-1-ene is only capable of existence as
a transient, its higher homologues having a double bond at the bridgehead position
have been isolated: e.g.
