7. Substitution Reactions

Starting with an alkyl halide, how could the following compounds be prepared?

a. 2-methoxybutane

How will the rate of each of the following S_N2 reactions change if it is carried out in a more polar solvent?

a.

Predict the major products of the following substitutions.

b.

For each pair, choose the haloalkane that would react most quickly in an S_N2 reaction.

(d)

Which of the following sets of conditions would most favor a successful $S_{\mathrm{N}}2$ reaction for a primary alkyl halide?

Starting with an alkyl halide, how could the following compounds be prepared?

c. butylmethylamine

Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (iii) SOCl₂ , NEt₃ (iv) 1. TsCl, Et₃N 2. NaCN; If no reaction occurs, write 'no reaction.'

(f)

Which of the following compounds will undergo an $S_{\mathrm{N}}2$ reaction most readily?

Cardura, a drug used to treat hypertension, is synthesized as shown here.

b. Show the mechanism for conversion of A to B. Which is formed more rapidly, A or B?

Which of the following is a property of the $S{N}_2$ reaction mechanism?

2-Acetoxycyclohexyl tosylate reacts with acetate ion to form 1,2-cyclohexanediol diacetate. The reaction is stereospecific—that is, the stereoisomers obtained as products depend on the stereoisomer used as a reactant. Recall that because 2-acetoxycyclohexyl tosylate has two asymmetric centers, it has four stereoisomers—two are cis and two are trans. Explain the following observations:

b. Both trans reactants form the same racemic mixture.

Predict the products of the following S_N2 reactions.

(e)

(f)