Reaction of hexa-2,4-diene and acrolein
Click the structures and reaction arrows in sequence to view the 3D models and animations respectively
In this case both the diene and dienophile have stereochemistry. Although there are four stereogenic centres in the product only two diastereoisomers can be formed. The diastereoisomers formed are known as exo and endo.
The endo product is favoured, but which one is it? The easiest way to work this out is by drawing the reactants coming together in 3D. See one method for working this out.