15P - Organic Chemistry (Mcmurry)

Question

Question: How would you prepare the following compound using an acetoacetic ester synthesis?

Step-by-Step Solution

Answer

Step 1: The given compound

Step 1: The given compound

Step 2: Explanation

The base ethoxide ion abstracts a proton from the methylene group and forms an enolate ion.

Then the enolate ion attacks 1,4-dibromobutane and displaces a bromide ion.

Then again the ethoxide ion abstracts second proton from the methylene group and forms another enolate ion.

Then the enolate ion attacks the other end of the 1,4-dibromobutane and displaces a bromide ion.

Thus the cyclic keto ester forms.

Then hydrolysis of the keto ester with dilute acids and decarboxylation by heating forms the required product.

Step 3: Conclusion

Thus you can prepare the given compound using an acetoacetic ester synthesis.