Chapter 17, Problem 17.80P

Interpretation Introduction

(a)

Interpretation:

The structure of the product is to be drawn for the given reaction from the given data.

Concept introduction:

The $\text{α,β}$$\text{-}$ unsaturated carbonyl compounds have two electrophilic centers. One is the carbonyl carbon yielding the direct addition product; the second is the $\text{β}$ carbon yielding the conjugate addition product.

Thus, both can react with the nucleophile depending, on the nature of the nucleophile and the regioselectivity of the reaction.

When the nucleophile adds to the carbonyl carbon, the reaction yields a $\text{1, 2-addtion}$ product, and the final product is alcohol in this case.

When the nucleophile adds to the $\text{β}$ carbon of the carbonyl compound, the reaction yields a $\text{1, 4-addition}$ product, keeping the carbonyl group intact.

A broad absorption between ${\text{3200 - 3600 cm}}^{\text{-1}}$ in IR spectrum is characteristic of an $\text{O-H}$ stretching, and a band near ${\text{1700 cm}}^{\text{-1}}$ is characteristic of the carbonyl group.

Interpretation Introduction

(b)

Interpretation:

it is to be argued whether the nucleophile adds reversibly or irreversibly to the carbonyl group in the given reaction.

Concept introduction:

The $\text{α,β}$$\text{-}$ unsaturated carbonyl compounds have two electrophilic centers. One is the carbonyl carbon yielding the direct addition product; the second is the $\text{β}$ carbon yielding the conjugate addition product.

Thus, both can react with the nucleophile depending, on the nature of the nucleophile and the regioselectivity of the reaction.

When the nucleophile adds to the carbonyl carbon, the reaction yields a $\text{1, 2-addtion}$ product, and the final product is alcohol in this case.

When the nucleophile adds to the $\text{β}$ carbon of the carbonyl compound, the reaction yields a $\text{1, 4-addition}$ product, keeping the carbonyl group intact.

A broad absorption between ${\text{3200 - 3600 cm}}^{\text{-1}}$ in IR spectrum is characteristic of an $\text{O-H}$ stretching, and a band near ${\text{1700 cm}}^{\text{-1}}$ is characteristic of the carbonyl group.