Chapter 18, Problem 18.1P

Interpretation Introduction

(a)

Interpretation:

A mechanism of given reaction under neutral condition is to be drawn.

Concept introduction:

The carbonyl carbon is electrophilic in nature due to the electronegativity difference between the carbonyl carbon and oxygen. Since water is amphoteric in nature can act as acid as well as a base depending on availability and the reaction condition. Under neutral conditions, water acts as the nucleophile.

Answer to Problem 18.1P

A mechanism of given reaction under neutral condition is:

Explanation of Solution

The given reaction is:

Under neutral conditions, water acts as the nucleophile. The electrophilic addition step increases the total number of charges by two as shown below,

Conclusion

Under neutral conditions, water acts as a nucleophile.

Interpretation Introduction

(b)

Interpretation:

A mechanism of given reaction under basic condition is to be drawn.

Concept introduction:

Under basic conditions, the nucleophile becomes stronger and the electrostatic attraction is increased when the uncharged nucleophile is converted into a negatively charged nucleophile.

Answer to Problem 18.1P

A mechanism of given reaction under neutral condition is:

Explanation of Solution

The given reaction is:

Under basic conditions, ${\text{HO}}^{\text{-}}$ is present in a significant concentration and can thus act as the nucleophile. The total number of charges remains the same under basic conditions. Thus, nucleophilic addition is faster under basic conditions.

Conclusion

Under basic conditions, the nucleophile becomes stronger.