Chapter 21, Problem 21.57AP

Interpretation Introduction

(a)

Interpretation:

The curved arrow mechanism for the given reaction is to be explained.

Concept Introduction:

The reaction of carbon dioxide with water forms carbonic acid. The carbon dioxide acts as an electrophile. Lone pair of the water molecule acts as the nucleophile. The nucleophilic addition reaction takes place between carbon dioxide and water.

Interpretation Introduction

(b)

Interpretation:

The curved arrow mechanism for the given reaction is to be explained.

Concept Introduction:

In the hydrolysis of halo lactone, Grignard reagent is used as an intermediate. The given halo lactone is first converted into alkylmagnesium halide by reaction of halo lactone with magnesium in the presence of ether. Then, the alkylmagnesium halide lactone undergoes hydrolysis in presence of acid.

Interpretation Introduction

(c)

Interpretation:

The curved arrow mechanism for the given reaction is to be explained.

Concept Introduction:

The ring opening of the lactone takes place in presence of ethanol and hydrogen bromide to form bromoacid. The bromoacid formed then undergoes esterification reaction to form the bromo ester compound. The esterification reaction is the reaction in which the formation of esters from acid takes place.

Interpretation Introduction

(d)

Interpretation:

The curved arrow mechanism for the given reaction is to be explained and compound A is to be identified.

Concept Introduction:

The reaction of alkene with mercuric acetate and then reduction with sodium borohydride to form alcohol is known as oxymercuration-demercuration reaction. The addition of mercuric acetate to the double bond is oxymercuration. The reduction of mercury in presence of sodium borohydride is demercuration.

Interpretation Introduction

(e)

Interpretation:

The curved arrow mechanism for the given reaction is to be explained.

Concept Introduction:

Lactones are cyclic ester compounds. Lactones are formed by the reaction between carboxylic acid and hydroxyl group present in the same compound. The lactones have ring strucuture. Lactone formation takes place in acidic conditions.