Acetoacetic Ester

Reactions of Carbonyl and Related Compounds Acetoacetic Ester Syntheses, Acetoacetic ester synthesis is a chemical reaction where ethyl acetoacetate is alkylated at the á-carbon to both carbonyl groups and then converted into a ketone, or more specifically an á-substituted acetone. This is very similar to malonic ester synthesis.

Mechanism A strong base deprotonates the dicarbonyl á-carbon. This carbon is preferred over the methyl carbon because the formed enolate is conjugated, and thus resonance stabilized. The carbon then undergoes nucleophilic substitution. When heated with aqueous acid, the newly alkylated ester is hydrolyzed to a â-keto acid, which is decarboxylated to form a methyl ketone.

1.

What product is formed when 1-bromobutane is used in an acetoacetic ester synthesis?

(A)2-heptanone(B)2-hexanone(C)2-pentanone(D)hexanoic acid(E)heptanoic acid

2

Identify the correct sequence of reagents employed in an acetoacetic ester synthesis.

(A) (B) (C) (D) (E)

1) alkyl bromide (2) warm acid-catalyzed hydrolysis (3) alkoxide ion (1) warm acid-catalyzed hydrolysis (2) alkoxide ion (3) alkyl bromide (1) alkoxide ion (2) warm acid-catalyzed hydrolysis (3) alkyl bromide (1) alkyl bromide (2) alkoxide ion (3) warm acid-catalyzed hydrolysis (1) alkoxide ion (2) alkyl bromide (3) warm acid-catalyzed hydrolysis