7. Substitution Reactions

For each solvent, indicate the most likely substitution reaction to take place.

(a)

Predict the product of the following substitution reactions, making sure to note whether a rearrangement should occur.

(d)

Explain how 1-butanol can be converted into the following compounds:

a.

What nucleophiles would form the following compounds as a result of reacting with 1-iodobutane?

e.

f.

Suggest a mechanism for the following substitution reactions.

(b)

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

b. Explain, by showing the mechanisms, why different substitution products are obtained.

Using cyclohexane as one of your starting materials, show how you would synthesize the following compounds.

(c)

Suggest a mechanism for the following reactions.

(a) Substitution:

What is the major product of each of the following reactions?

a.

A solution of pure (S)-2-iodobutane ([α] = +15.90°) in acetone is allowed to react with radioactive iodide, ¹³¹I^–, until 1.0% of the iodobutane contains radioactive iodine. The specific rotation of this recovered iodobutane is found to be +15.58°.

b. What does this result suggest about the mechanism of the reaction of 2-iodobutane with iodide ion?

Order the following molecules on the basis of their nucleophilic strength using the pKₐ values of their conjugate acids.

Starting with (R)-1-deuterio-1-propanol, how could you prepare

c. (R)-1-deuterio-1-methoxypropane?

When tert-butyl bromide is heated with an equal amount of ethanol in an inert solvent, one of the products is ethyl tert-butyl ether.

a. What happens to the reaction rate if the concentration of ethanol is doubled?

Would the following nucleophiles be more likely to participate in an S_N1 or S_N2 reaction?

(f)

Draw the substitution products for each of the following reactions; if the products can exist as stereoisomers, show what stereoisomers are obtained:

e. 1-bromo-2-butene + CH₃O⁻

f. 1-bromo-2-butene + CH₃OH