Chapter 11.8, Problem 16P

(a)

Interpretation Introduction

Interpretation:

To predict the products of the following transesterification reaction.

  $\text{ethyl benzoate + excess isopropanol + HCl}$

Concept Introduction:

Transesterification is the process of formation of a new ester molecule from the reaction of alcohol and an ester.  This is like hydrolysis of ester but here nucleophile is alcohol molecule instead of ${\text{H}}_{\text{2}}\text{O}$.  As alkoxide groups have same basicity, therefore, an excess amount of alcohol is used.  The addition of an acid also increases the rate of reaction by protonating the carbonyl oxygen atom.  A general transesterification is written as,

(b)

Interpretation Introduction

Interpretation:

To predict the products of the following transesterification reaction.

  $\text{phenyl acetate + excess ethanol + HCl}$

Concept Introduction:

Transesterification is the process of formation of a new ester molecule from the reaction of alcohol and an ester.  This is like hydrolysis of ester but here nucleophile is alcohol molecule instead of ${\text{H}}_{\text{2}}\text{O}$.  As alkoxide groups have same basicity, therefore, an excess amount of alcohol is used.  The addition of an acid also increases the rate of reaction by protonating the carbonyl oxygen atom.  A general transesterification is  written as,