8. Elimination Reactions

For each reaction, decide whether substitution or elimination (or both) is possible, and predict the products you expect. Label the major products.

b. 1-bromo-1-methylcyclohexane + triethylamine(Et₃N:)

Give the substitution and elimination products you would expect from the following reactions.

b. 1-iodo-1-phenylcyclopentane heated in ethanol

Predict the major and minor elimination products of the following proposed reactions (ignoring any possible substitutions for now). In each case, explain whether you expect the mechanism of the elimination to be E1 or E2.

(b)

Predict the products and mechanisms of the following reactions. When more than one product or mechanism is possible, explain which are most likely.

a. 1−bromohexane + sodium ethoxide in ethanol

Predict the products and mechanisms of the following reactions. When more than one product or mechanism is possible, explain which are most likely.

b. 2−chlorohexane + NaOCH₃ in methanol

When (±)−2,3−dibromobutane reacts with potassium hydroxide, some of the products are (2S,3R)-3-bromobutan-2-ol and its enantiomer and trans-2-bromobut-2-ene. Give mechanisms to account for these products.

Make models of the following compounds, and predict the products formed when they react with the strong bases shown.

(c) (d,l)-1,2-dibromo-1,2-diphenylethane + (CH₃CH₂)₃N:

Make models of the following compounds, and predict the products formed when they react with the strong bases shown.

(d)

Propose mechanisms for the following reactions. Additional products may be formed, but your mechanism only needs to explain the products shown.

(c)

Silver-assisted solvolysis of bromomethylcyclopentane in methanol gives a complex product mixture of the following five compounds. Propose mechanisms to account for these products.

(c)

Silver-assisted solvolysis of bromomethylcyclopentane in methanol gives a complex product mixture of the following five compounds. Propose mechanisms to account for these products.

(d)

Silver-assisted solvolysis of bromomethylcyclopentane in methanol gives a complex product mixture of the following five compounds. Propose mechanisms to account for these products.

(e)

Draw the products of each of the following S_N2/E2 reactions. If the products can exist as stereoisomers, show which stereoisomers are formed.

b. (3R,4R)-3-bromo-4-methylhexane + CH₃O⁻

Which of the following compounds would react faster in an

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a. E1 reaction?

b. E2 reaction?

What product is obtained when the following compound undergoes two successive elimination reactions?