9. Alkenes and Alkynes

For each set of isomers, choose the isomer that you expect to be most stable and the isomer you expect to be least stable.

(b)

Bromination of buta-1,3-diene with a single equivalent of Br₂ can give either of two products. (a) Which of these products (A or B) would you predict to be more stable? Justify your answer.

Conjugated dienes, molecules containing two alkenes separated by one single bond, are discussed in detail in Chapter 21.

(a) Considering the observed ∆H° of hydrogenation, is hexa-1,3-diene (conjugated) or hexa-1,4-diene (unconjugated) more stable?