Question

Barbiturates, including "truth serums" seen in movies like Meet the Fockers and sedatives that may have led to the untimely death of Jimi Hendrix, are often synthesized using what type of reaction sequence involving two consecutive enolate alkylations

Answer 1

Step-by-step explanation:

Diethyl malonate is more acidic than monocarbonyl compounds (pKa=13) due to their alpha hydrogens being attached to two carbonyl groups. Thus, the malonic ester is easily converted to its enolate ion by reaction with sodium ethoxide in ethanol. The product of the alkylation of the malonic ester leaves a hydrogen atom acid in an alpha position, so the alkylation process can be repeated a second time to produce a dialkylated malonic ester.

In this case, when urea is treated with diethyl malonate in the presence of sodium ethoxide base, the second alkylation step occurs intramolecularly to generate a cyclic product, barbituric acid.