Organic Chemistry 2: Conjugated Systems & Diels-Alder Reactions
Predict the product of 1,3-butadiene reacting with ethene.
Answer and explanation
Cyclohexene. This is the basic Diels-Alder cycloaddition product.
Predict the favored product of 1,3-butadiene reacting with maleic anhydride.
Answer and explanation
The endo cyclohexene anhydride product is favored.
What happens when an s-cis conjugated diene reacts with an alkene dienophile?
Answer and explanation
A Diels-Alder reaction can form a cyclohexene product because the diene is in the s-cis conformation.
Predict the product type when a conjugated diene reacts with an alkyne dienophile.
Answer and explanation
An alkyne dienophile gives a cyclohexadiene product.
Predict the product of an alkene with an allylic hydrogen treated with NBS and light.
Answer and explanation
An allylic bromide forms; bromination occurs at the allylic position.
Predict the product of cyclohexene treated with NBS and light.
Answer and explanation
3-bromocyclohexene forms by allylic bromination.
Predict the major product type for low-temperature HBr addition to 1,3-butadiene.
Answer and explanation
The 1,2-addition product is favored at low temperature; it is the kinetic product.