Question

How would you prepare the following ketone using either an acetoacetic ester or a malonic ester synthesis? a) 3-ethyl-2-pentanone b) Hex-1-en-5-one

Answer 1

Since in both cases you need a ketone the acetoacetic acud synthesis can be used:

a) You need to identify the carbons you want to add to the alpha carbon of the acetoacetic acid.

you need to add twice ethyl bromide in the alpha carbon according to the following synthesis (the blue atoms are the one from the ethyl bromide)

b)You need to identify the carbons you want to add to the alpha carbon of the acetoacetic acid.

you need to add a bromide with three carbons, and also a double bond to the alpha carbon according to the following synthesis (the blue atoms are the one from the 3-Br-prop-1-ene)