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)

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

(c)

In 1935, J. Bredt, a German chemist, proposed that a bicycloalkene could not have a double bond at a bridgehead carbon unless one of the rings contains at least eight carbons. This is known as Bredt's rule. Explain why there cannot be a double bond at this position.