[cseil]

Hello,
I have to synthesise from the cyclohexanone.

Could you give me some hints to start? Thank you

[Dan]

What C-C bond forming reactions do you know?

[cseil]

Acetoacetic ester synthesis (could be), Malonic esther synthesis, Michael Reaction, Aldolic addition, claisen condensation.. these are the ones related to the compound I want to synthesise.

I was thinking about the acetoacetic esther synthesis with the 3-bromocyclohexanone. But the fact is I have to start from the cyclohexanone and I don't know how to beta-halogenate the ketone..

[Dan]

Acetoacetic ester synthesis (could be), Malonic esther synthesis, Michael Reaction, Aldolic addition, claisen condensation.. these are the ones related to the compound I want to synthesise.

I was thinking about the acetoacetic esther synthesis with the 3-bromocyclohexanone. But the fact is I have to start from the cyclohexanone and I don't know how to beta-halogenate the ketone..

Of the reactions you listed, do any of then give a product where the C-C bond forms β to a carbonyl?

[cseil]

I don't know if this is right. The Michael Reaction is the only one that can produce a CC bond on the β carbon.
The fact is I thought I could use only some kind of enolates for the Michael Reaction (β-ketoesters, β-diesters ecc..).

EDIT: I can start from the cyclohexanone, halogenate the α carbon, then do an E2 reaction and produce the α-β unsaturated compound. Then everything I wrote.

[Dan]

Charges and curly arrows in the first step need checking, but otherwise the strategy looks good.

[orgopete]

Although this strategy looks good, I doubt this will work. Practically, acetone is going to self-condense, but I don't think most students would know this. My model for predicting 1,2 v 1,4-additions is as follows. If the product of the 1,2-addition is a weaker base than the reactant, that is the tetrahedral intermediate cannot reverse to give a weaker base, then the product will be a 1,2-addition product, e.g. Grignard, hydride, aldol, etc. if that intermediate can give a weaker base, then it can reverse, e.g., halides, water, alcohol, etc. If it can reverse, then a kinetically slower 1,4-addition may also occur. If this product becomes protonated (or otherwise complexed), then the weakly basic conditions would be unable to reverse this reaction and give the product of a 1,4-addition.

Hint, how can the acidity of the alpha protons of acetone be increased?