9. Alkenes and Alkynes

Which mechanism best describes the formation of the major product(s) in the dehydrohalogenation of $2_{-}-bromobutane$?

Which of the following is the major organic product formed in the E2 dehydrohalogenation of $C_2{H}_5\mathrm{Br}$ (bromoethane) with a strong base such as $\mathrm{NaOH}$?

Predict the dehydrohalogenation product(s) that result when the following alkyl halides are heated in alcoholic KOH. When more than one product is formed, predict the major and minor products.

(d)

(e)

Predict the dehydrohalogenation product(s) that result when the following alkyl halides are heated in alcoholic KOH. When more than one product is formed, predict the major and minor products.

(a)

(b)

(c)

Predict the dehydrohalogenation product(s) that result when the following alkyl halides are heated in alcoholic KOH. When more than one product is formed, predict the major and minor products.

(f)

Predict the products formed by sodium hydroxide-promoted dehydrohalogenation of the following compounds. In each case, predict which will be the major product.

a. 1-bromobutane

b. 2-chlorobutane

c. 3-bromopentane

Predict the products formed by sodium hydroxide-promoted dehydrohalogenation of the following compounds. In each case, predict which will be the major product.

d. cis-1-bromo-2-methylcyclohexane

Predict the products formed by sodium hydroxide-promoted dehydrohalogenation of the following compounds. In each case, predict which will be the major product.

e. trans-1-bromo-2-methylcyclohexane

What halides would undergo E2 dehydrohalogenation to give the following pure alkenes?

d. methylenecyclohexane

What halides would undergo E2 dehydrohalogenation to give the following pure alkenes?

e. 4-methylcyclohexene