Question

Malonic ester (diethyl malonate) is treated successively with sodium ethoxide (1 eq.), ethyl bromide, potassium tert-butoxide, isobutyl chloride, hot aqueous naoh, hcl, and heat. what is the final product?

Answer 1

In first step the acidic proton at alpha position is abstracted by NaOEt and forms Enolate.
The resulting enolate undergoes SN² reaction with Ethyl Bromide.
The resulting product again on treatment with Potassium tertiary Butoxide gives corresponding Enolate.
This second enolate on treatment with Isobutyl Chloride undergo SN² reaction.
At last treatment with NaOH (aq) and HCl at high temperature yield 2-Ethyl-4-methylpentanoic Acid.