Predict the product for the following substitution reactions. Indicate whether each reaction likely proceeds by an S_N1 or S_N2 mechanism.
(c)

Predict the product of the substitution reactions, paying attention to the stereochemical outcome.

(b)

Crown ethers are able to solvate cations based on their size. Specifically, 15-crown-5 forms stable complexes with sodium. How would the addition of a crown ether change the rate of an S_N2 reaction?

To solve this problem, you need to read the description of the Hammett $\sigma$, $\rho$ treatment given in [Chapter 15, Problem 92]. When the rate constants for the hydrolysis of several morpholine enamines of para-substituted propiophenones are determined at pH 4.7, the $\rho$ value is positive; however, when the rates of hydrolysis are determined at pH 10.4, the $\rho$ value is negative.

b. What is the rate-determining step of the hydrolysis reaction when it is carried out in an acidic solution?

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Predict the product for the following substitution reactions. Indicate whether each reaction likely proceeds by an S_N1 or S_N2 mechanism.

(b)

Predict the product(s) of the following reactions.

(h)

The benzylic bromide shown undergoes neither S_N1 nor S_N2 substitution reactions. Explain.

Predict the product for the following substitution reactions. Indicate whether each reaction likely proceeds by an S_N1 or S_N2 mechanism.

(a)

Would you expect the following substitution reaction to proceed with inversion or racemization? Why?