Chapter 11.14, Problem 28P

(a)

Interpretation Introduction

Interpretation:

The acyl chloride and carboxylate ion that could be used to form the given mixed anhydride have to be found.

Concept Introduction:

Mixed anhydrides are unsymmetrical anhydrides which have different alkyl groups.

Example:

  

The acetyl chloride and carboxylate ion that could be used to form any given mixed anhydride can be analysed using the simple retro analysis as shown here:

  

(b)

Interpretation Introduction

Interpretation:

The other reagents that could be used to form the given mixed anhydride have to be found.

Concept Introduction:

Mixed anhydrides are unsymmetrical anhydrides which have different alkyl groups.

Example:

Any anhydride can be obtained using the following two pairs of reagents:

1. 1. Acetyl chloride and a carboxylate ion.

  

1. 2. Two different carboxylic acids if mixed or unsymmetrical anhydride has to be formed or two same carboxylic acids if symmetrical anhydride has to be formed.

  

For any simple anhydride, the two carboxylic acids from which it has been formed can be found by the simple retro analysis as shown here: