Diels-Alder with an aromatic diene

Reaction class

Cycloaddition

Typical conditions

Heat, often neat or in a sealed tube. The addition is reversible, so the adduct is favoured at lower temperatures and the starting materials return on strong heating.

Mass balance

balanced — the co-products are written out, not dropped

Mechanism

Diels-Alder with an aromatic diene, one concerted step

Conditions are what the literature ordinarily uses, recorded so you can see whether yours are in the usual range. They are not a procedure and they are not scaled to your flask.

The same six electrons moving round at once, except that the diene is an aromatic ring and gives up its aromaticity to react.

1. 1The aromatic ring adds across the alkene

This is the pathway taught for the class, not a record of what was observed. On the platform it is drawn on the structures you supply, with the curly arrows on the atoms that actually move.