8. Elimination Reactions

Identify the bonds that break and form in the following elimination reactions.

(b)

a. Explain why 1-bromo-2,2-dimethylpropane has difficulty undergoing both S_N2 and S_N1 reactions.

b. Can it undergo E2 and E1 reactions?

What is the major organic product formed when $C_2{H}_5{\mathrm{Br}}_1$ (ethyl bromide) reacts with a strong base such as $O_2{H}_1-$ (ethoxide ion) in an E2 elimination reaction?

When a secondary haloalkane is treated with sodium ethoxide in ethanol, we predict alkene formation over ether formation. How did we make this determination?

What are the products of the following reactions?

g.

h.

Predict the major product(s) of the following elimination reactions, paying close attention to the stereochemical outcome of the reactions.

(a)

Which compound has the greatest rate of hydrolysis at pH = 3.5: benzamide, o-carboxybenzamide, o-formylbenzamide, or o-hydroxybenzamide?

Which of the following is the major $E_2$ reaction product formed when $\text{cis-1-chloro-2-ethylcyclohexane}$ is treated with a strong base?

cis-4-Bromocyclohexanol and trans-4-bromocyclohexanol form the same elimination product but a different substitution product when they react with HO⁻.

a. Why do they form the same elimination product?

When $2-\mathrm{bromo}-2,3-\mathrm{dimethylbutane}$ is heated with $\mathrm{sodium} \mathrm{methoxide}$, which is the major alkene product formed via the $E2$ mechanism?

Indicate how each of the same factors affects an E2 reaction.

1. the strength of the base

2. the concentration of the base

3. the solvent

When 2-bromopropane is treated with sodium ethoxide, propene is produced. What molecule is lost from 2-bromopropane in this process?

Which of the following alkyl halides reacts the fastest in an $E2$ reaction?

Draw the structure of DDE.

Draw the major product obtained when each of the following alkyl halides undergoes an E2 reaction:

e.