Q 14-14-40 E-c - Organic Chemistry (Mcmurry)

Question

How could you use Diels-Alder reactions to prepare the following products ? Show the starting diene and dienophile in each case.

c)

Step-by-Step Solution

Answer

You will find it out by working in a reverse direction of Diels –Alder reaction.

Diels-Alder reaction

Diels-Alder reaction was discovered by the German chemists Otto Diels and Kurt-Alder in 1928. Diels-Alder reaction is an important organic reaction which includes a substituted alkene in the form of a dienophile and a conjugated diene. It proceeds via concerted mechanism. Diels alder reaction can be used to generate 6 membered rings since there is a simultaneous construction of two new Carbon-carbon bonds.

Diene and dienophile

Diene is an organic compound which comprises of two conjugated pi bonds (4 pi bonds) while dienophile is a diene loving compound containing 2 pi electrons. When the interaction between them, occurs a transition state without any additional energy barrier, is obtained.

Predicting the Diene and dienophile

By working out in a reverse direction of Diels-Alder reaction or by breaking the bonds in our imagination, which were formed during the cycloaddition reaction (Diels-Alder reaction) we can predict the diene and dienophile of the given reaction.

                                    Diels-Alder reaction