Chapter 7, Problem 7.58P

Interpretation Introduction

Interpretation:

The product for each given step with appropriate curved arrows is to be drawn.

Concept introduction:

In the nucleophilic addition step, the nucleophile adds to the polar $\text{π}$ bond. The nucleophile is relatively electron rich, and the polar $\text{π}$ bond is relatively electron poor. Thus, the curved arrow drawn from the nucleophile to the polar $\text{π}$ bond represents the flow of electrons from an electron rich site to an electron poor site.

In the nucleophilic elimination step, the more electronegative atom bears full negative charge or partial negative charge. This is the electron rich atom and the less electronegative atom bonded to an electronegative atom is relatively electron poor. The curved arrow drawn from the lone pair of electron rich atom points to the bonding region between the more electronegative atom and less electronegative atom representing the electron flow from an electron rich site to an electron poor site. The second curved arrow is drawn to represent the breaking of the bond between the less electronegative atom and the leaving group to avoid exceeding an octet on the less electronegative atom.