ISSUE:

Hello everyone.

I need your help in a couple of exercises please.



First attached file b: In that exercise I don't know how to break the carbon-carbon bond.



Any ideas? What I have: I just added the OH l carbon 3 since there is resonance. From then on I don't know how to go on. Second attached file section C: In this exercise I am not sure which would be the most acidic hydrogen: if the one in the middle of the two carbonyls of the ester, if the carbon number 3 of the acetone or if the carbon number 1 of the ketone (due to its proximity to the bromine). I have not been able to start the reaction for that doubt. What I did was remove the hydrogen from carbon 3 of the ketone and then I reacted it with the ester. The result was a 1-bromo3methyl 2,4,6-heptanone. Another thing that causes me doubt is the presence of bromine. Since it is a good leaving group it could react by removing the acidic hydrogen from the ester. It could even come out because of the base. It is really difficult to know which is the predominant product. Funny

Hello, in b) you have a retroaldol.
First you add the hydroxide ion to the beta carbon of the alpha, beta-unsaturated, make an acid-base balance and give up the oxygen pair breaking the CC bond. In section C it is more important that a stable cycle is formed, with 5 or 6 members, than the acidity of the hydrogen itself.

I would choose the alpha of one of the neighboring esters that cycles forming a cycle of 5. Greetings!