||Chapter 10: Conjugation in Alkadienes and Allylic
Reactions of Dienes
In general terms, dienes undergo electrophilic addition
reactions in a similar fashion to alkenes (review)
However, in a little more detail:
Our attention here will focus on conjugated dienes.
- Conjugated dienes undergo addition but the proximity
of the conjugated C=C influences the reactions
- Isolated dienes react just like alkenes (chapter
- Cumulated dienes react more like alkynes (after all, both have sp hybridised
- The π bonds are a region
of high electron density (red).
- Therefore, conjugated dienes are typically nucleophiles.
- Hence, dienes react with electrophiles (e.g. H+,
- Dienes can undergo addition reactions in which
one or both of the π bonds are converted
to new stronger σ bonds.
- Overall reaction : Electrophilic addition
The reactions that will be considered in the following sections