Conjugated Pi Systems and Pericyclic Reactions

Fill in the blanks below. To verify that your answers are correct, look in your textbook at the end of Chapter 17. Each of the sentences below appears verbatim in the section entitled Review of Concepts and Vocabulary. 

Conjugated dienes experience free-rotation about the C2-C3 bond, giving rise to two important conformations s- and s-. The conformation is lower in energy. 

When butadiene is treated with HBr, two major products are observed, resulting from  

Conjugated dienes that undergo addition at low temperature are said to be under  

High temperatures can often be used to achieve the reverse of a Diels-Alder reaction, called a Diels-Alder. 

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