Q61E - Organic Chemistry (Mcmurry)

Question

In contrast to the rapid reaction shown in Problem 23-60, ethyl acetoacetate requires a temperature over 150 °C to undergo the same kind of cleavage reaction. How can you explain the difference in reactivity?

Step-by-Step Solution

Answer

Ethyl acetoacetate requires a temperature over $150°C$ to undergo the same kind of cleavage reaction because its acetoacetate anion becomes stabilized by resonance and becomes unreactive towards nucleophiles.

In Problem 23-60

In Problem 23-60, it does not contain any 𝛂– hydrogen between its carbonyl groups and therefore not stabilized by resonance, hence cleavage of bond occurs followed by elimination of ethyl dimethyl acetate anion occurs.

In the case of ethyl acetoacetate

In the case of ethyl acetoacetate, since it contains 𝛂 – hydrogen between its carbonyl groups and forms acetoacetate anion by the attack of ethoxide ion which is stabilized by resonance and becomes unreactive towards nucleophiles, hence it requires a high temperature of 150⁰C to undergo the same kind of cleavage reaction.