10.3 The Diene

10.3 The Diene

• Diels-Alder reactions were the focus of the previous section.
• The diene is one of the reactants in Diels-Alder reactions.
• The diene has two p bonds.
• There are several conditions that must be met in order for a diene to react with a dienophile.

• There is an important condition that must be met in order for a diene to react in a Diels-Alder reaction.

• When cyclopentadiene is used as the diene in a Diels-Alder reaction, the reaction occurs very quickly because all of the diene spend 100% of the time in the same place.

• When cyclopentadiene is used as the diene in a Diels-Alder reaction, we need to draw the product that we expect.
• The extra carbon atom is expected to come along for the ride.

• Draw a pattern that connects the tops of the roof to form a pi bond.

• The structure is shown.

• The other side will be connected last.

• You can practice these steps on a blank piece of paper and draw the skeleton without instructions.
• Whenever cyclopentadiene is used as the diene in a Diels-Alder reaction, a skeleton will be formed.

• We expect a bicyclic structure in this Diels-Alder reaction.

• The aldehyde groups must be placed at positions C5 and C6 when we draw the product.
• The configuration of the dienophile must be preserved in the product when drawing these substituents.

• The two structures that we expect are not actually produced by the reaction.

• There are two products that represent a pair of enantiomers.

• The plane of the mirror is in between the two compounds, so they are mirror images.

• We expect a Diels-Alder reaction from the reactants.

• Draw a pattern that connects the tops of the roof to form a pi bond.

• The structure is shown.

• The other side will be connected last.

• The group goes here.

• There are two products that represent a pair of enantiomers.