7. Substitution Reactions

Fill in the squares in the following chemical equations:

a.

b.

Fill in the squares in the following chemical equations:

c.

d.

What substitution products are obtained when each of the following compounds is added to a solution of sodium acetate in acetic acid?

a. 2-chloro-2-methyl-3-hexene

b. 3-bromo-1-methylcyclohexene

Draw the substitution products for each of the following S_N2 reactions. If the ­products can exist as stereoisomers, show which stereoisomers are formed:

a. (3S,4S)-3-bromo-4-methylhexane + CH₃O^-

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

Draw the substitution products for each of the following S_N2 reactions. If the ­products can exist as stereoisomers, show which stereoisomers are formed:

c. (3R,4R)-3-bromo-4-methylhexane + CH₃O^-

d. (3R,4S)-3-bromo-4-methylhexane + CH₃O^-

Propose a mechanism for the following reaction.

Draw the substitution and elimination products.

a.

b.

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

a.

b.

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

e.

f.

Aldolase shows no activity if it is incubated with iodoacetic acid before fructose-1,6-bisphosphate is added to the reaction mixture. What causes this loss of activity?

Predict the major products of the following substitutions.

a.

Predict the major products of the following substitutions.

f.

Chlorocyclohexane reacts with sodium cyanide (NaCN) in ethanol to give cyanocyclohexane. The rate of formation of cyanocyclohexane increases when a small amount of sodium iodide is added to the solution. Explain this acceleration in the rate.

Draw perspective structures or Fischer projections for the substitution products of the following reactions.

(b)

a. Optically active 2-bromobutane undergoes racemization on treatment with a solution of KBr. Give a mechanism for this racemization.

b. In contrast, optically active butan-2-ol does not racemize on treatment with a solution of KOH. Explain why a ­reaction like that in part (a) does not occur.