Dienes can be divided into three classes:
- Unconjugated dienes have the double bonds separated by two or more single bonds.
- Conjugated dienes have conjugated double bonds separated by one single bond. They are also the most stable.
- Cumulated dienes have the double bonds sharing a common atom as in a group of compounds called allenes.
Reactions with dienes
The 1,3 configuration of double bonds found in 1,3-butadiene (conjugated double bonds) make these types of dienes capable of participating in more reaction types than is the case for molecules with either just a single alkene functional group or with multiple, but non-alternating, alkene groups. One possible reaction for such dienes is the Diels-Alder reaction for example Danishefsky’s diene.