Chapter 17.7, Problem 21ATS

(a)

Interpretation Introduction

Interpretation:

Resonance structures of 3-methyl anisole have to be drawn.

Concept Introduction:

Resonance is an electron displacement effect for stabilizing a molecule through delocalization of bonding electrons in the pi orbital.

Delocalized electrons stabilize a compound. The extra stability gains from having delocalized electrons are called resonance stabilization or resonance energy.

(b)

Interpretation Introduction

Interpretation:

More dominant factor among the resonance effect and the inductive effect for the methoxy substituent has to be identified based on the given Birch reaction.

Concept Introduction:

Resonance is an electron displacement effect for stabilizing a molecule through delocalization of bonding electrons in the pi orbital.

Delocalized electrons stabilize a compound. The extra stability gains from having delocalized electrons are called resonance stabilization or resonance energy.

Inductive effect: It is an electronic effect occurs due to the difference in the electronegativity of atoms in a bond. This unequal sharing of electrons in the bond leads to a permanent dipole.

In Birch reduction, the benzene ring undergoes $\text{1,4}$ reduction where unconjugated cyclohexadienes are formed.

  

If the benzene ring has an electron donating substituent, the double bond next to it does not get reduced in Birch reduction.