Chapter 13, Problem 13.10P

Interpretation Introduction

(a)

Interpretation:

How the given transform would appear in a synthesis is to be shown.

Concept introduction:

A synthetic trap is a synthesis which prevents the reaction from occurring in the forward direction as planned. This occurs mainly because the reactant molecule contains multiple functional groups which interfere in the desired mechanism. However, even when there is only one functional group, a synthetic trap can still arise if a reaction takes place at two or more sites within that functional group. In such cases, regiochemistry is an issue. Regiochemistry is the specific region in the given molecule at which the reaction takes place selectively. We can choose a synthesis according to the regioselectivities of the functional group transformation reactions.

In epoxide ring opening reactions, the regiochemistry can be controlled by using acidic or basic/neutral medium. The nucleophile tends to attack the most substituted carbon atom under acidic conditions whereas a nucleophile tends to attack the least substituted carbon atom under neutral or basic conditions.

Interpretation Introduction

(b)

Interpretation:

How the given transform would appear in a synthesis is to be shown.

Concept introduction:

A synthetic trap is a synthesis which prevents the reaction from occurring in the forward direction as planned. This occurs mainly because the reactant molecule contains multiple functional groups which interfere in the desired mechanism. However, even when there is only one functional group, a synthetic trap can still arise if a reaction takes place at two or more sites within that functional group. In such cases, regiochemistry is an issue. Regiochemistry is the specific region in the given molecule at which the reaction takes place selectively. We can choose a synthesis according to the regioselectivities of the functional group transformation reactions.

In epoxide ring opening reactions, the regiochemistry can be controlled using acidic or basic/neutral medium. The nucleophile tends to attack the most substituted carbon atom under acidic conditions whereas a nucleophile tends to attack the least substituted carbon atom under neutral or basic conditions.