Diene

Dienes are polyenes.

Classes

Dienes can be divided into three classes:

1. Unconjugated dienes have the double bonds separated by two or more single bonds.
2. Conjugated dienes have conjugated double bonds separated by one single bond. They are also the most stable.
3. Cumulated dienes have the double bonds sharing a common atom as in a group of compounds called allenes.
4. Heterodienes have one or more of the unsaturated carbon atoms replaced with a heteroatom.

In Whiting reaction.

1,3-butadiene undergoes 1,2-addition and 1,4-addition.

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 Danishefsky’s diene.