Chapter 21, Problem 61DSP

Interpretation Introduction

Interpretation:

The final product obtained in the given reaction sequence is to be determined.

Concept Introduction:

Dianions can be prepared from $\text{β}$-keto esters by double deprotonation using strong bases such as LDA.

Protons on the $\text{α}$- carbon atoms in $\text{β}$-keto esters are flanked by two carbonyl groups and thus are far more acidic than those on the $\text{γ}$- carbon atoms. Therefore, the $\text{γ}$- carbon atom in $\text{β}$-keto esters is more basic and more nucleophilic than $\text{α}$- carbon atom. Alkylation of the dianion occurs at $\text{γ}$- carbon atom in $\text{β}$-keto esters.

In a given dihalo alkyl compound, the bromide ion is a good leaving group than the chloride ion.

Sodium azide is a salt and dissociates as sodium and azide ions. Azide ion is a strong nucleophile and thus it can replace the halogen atom in the given alkyl halide by an ${\text{S}}_{\text{N}}\text{2}$ reaction mechanism.

Potassium carbonate acts as a base and thus depronates the hydroxyl group in the hydroxyl acid derivative.