Chapter 23, Problem 23.62P

Interpretation Introduction

(a)

Interpretation: Two different halo ketones that can form A by an intramolecular alkylation reaction is to be drawn.

Concept introduction: Alkylation of aldehydes and ketones takes place in the presence of a strong base. The use of appropriate base, solvent and temperature can yield one major product regioselectively.

Lithium diisopropylamide (LDA) is a sterically hindered strong base. In an unsymmetrical ketone, it abstracts hydrogen from least substituted carbon to form kinetic product.

Interpretation Introduction

(b)

Interpretation: The synthesis of compound A from acetoacetic ester is to be devised.

Concept introduction: Alkylation of aldehydes and ketones takes place in the presence of a strong base. The use of appropriate base, solvent and temperature can yield one major product regioselectively.