[Jessie00]

Hi, I am sorry for my English. I can not do my homework. Could you help me with it please? 

[kriggy]

I think you should show us some work you already did, its forum rule.

btw hi form Czech :-D

[orgopete]

Hint, it looks as if Claisen condensation reaction is one of the topics. How can you convert the starting material to a Claisen reactant?

[kriggy]

Quite a good hint but even with it I always end with 5 membered or 7 membered ring and have too many steps or similar troubles

[orgopete]

Quite a good hint but even with it I always end with 5 membered or 7 membered ring and have too many steps or similar troubles

I agree. I didn't look at it very carefully. I'm not sure if 4 is supposed to be acetoacetate or an anion (for a Claisen). None the less, a Claisen intermediate requires a carbonyl anion synthon. I don't know if that was covered in the class. I don't see why toluene would be the starting material if 4 is acetoacetate.

[kriggy]

Maybe we are focusing too much on the Claisen?
What about this:


Its one more step but I think the oxidation of toluene to benzaldehyde is possible in one step with CrO₃ and acetanhydride but I dont have any reference book atm.. I also think that the addition of Bromoaceticacid derivative might also go to the methyl carbon..

[orgopete]

That looks like a perfectly fine strategy. Getting the aldehyde, not so much. I might suggest adding a benzyl Grignard to acetaldehyde as an alternative. Good suggestion though.

[kriggy]

Thats looks better. I knew that I somehow need to get phenylacetone so I found this reaction on wiki
http://en.wikipedia.org/wiki/Phenylacetone
Using grignard reaction would need two more steps If count right - reduce the acid to benzylalcohol then halogenation and make grignard then grignard reaction and then reduciton of hydroxygroup to ketone.
Or is there a way to halogenate toluene on that methyl group, which stops after single halogenation? I know about radical halogenation but this substitues all hydrogen AFAIK.

[Jessie00]

Maybe we are focusing too much on the Claisen?
What about this:


Its one more step but I think the oxidation of toluene to benzaldehyde is possible in one step with CrO₃ and acetanhydride but I dont have any reference book atm.. I also think that the addition of Bromoaceticacid derivative might also go to the methyl carbon..

Thank you very much. I dont understand what type of reaction is BrCH2COBr with Phenylacetone. Is it aldolisation?

[kriggy]

Just alkylation. α-protons are acidic so if you aply some base then you can alkylate them.