Diels-Alder cycloaddition:
The Diels-Alder cycloaddition reaction is a significant method through which six-membered rings can be synthesized. The reaction includes a conjugated diene and an alkene as displayed in figure.
![2289_Diels–Alder cycloaddition.png](https://www.expertsmind.com/CMSImages/2289_Diels%E2%80%93Alder%20cycloaddition.png)
Figure: Diels-Alder cycloaddition.
The alkene is considered to like a dienophile (diene-lover) and generally has an electron-withdrawing group related to it (for example a carbonyl group or a nitrile). The mechanism is planned with new bonds being created at the same time as old bonds are being broken. No intermediates are included.
![458_Diels–Alder cycloaddition1.png](https://www.expertsmind.com/CMSImages/458_Diels%E2%80%93Alder%20cycloaddition1.png)
Figure: Mechanism of Diels-Alder cycloaddition.