[orgobot]

Hi everyone,
I'm working on a synthesis problem that really looks like a Mannich reaction (ketone, formaldehyde, amine).  The thing is we need to start with given molecules as our only carbon source.  I'm given cycloheptene as a starting molecule but if it is a Mannich reaction, it looks like I need a cyclohexanone.

My question is, is it possible to synthesize cyclohexanone from cycloheptene?  My first thought was ozonolysis --> aldol but then I'm stuck.  I've also tried to figure out other ways that aren't Mannich reactions but I get stuck there.  Does anyone have any hints in the right direction?  Thanks   

edit: my bad. I meant cyclohexanone, not cyclohexanal...

[macman104]

If you provide the structure, people would be able to say whether they agree with your choice of Mannich.

What about addition with an aqueous halogen, oxidation of the alcohol to a ketone and then favorskii rearrangement to get the carboxylic acid.  If you need the aldehyde, reduce to the alcohol and oxidize with PCC.

[orgobot]

Apologies! First, I meant cyclohexanone, since Mannich needs a ketone.
I'm not sure how to properly name the structure, but it looks like the result of a Mannich given a cyclohexanone, formaldehyde, and a methyl amine.

[macman104]

So...like this?

[orgobot]

yes, that is it.

[Yarr]

My question is, is it possible to synthesize cyclohexanone from cycloheptene?

1) Treatment with CrO2Cl2 in acetone to get 2-chlorocycloheptanone.

2) 2-chlorocycloheptanone + NaHO, then acidify, to get cyclohexanecarboxilic acid.

3) Br2, HgO, heat, to get cyclohexyl bromide.

4) Oxidation with DMSO to get cyclohexanone.

[orgobot]

Hi Yarr, thanks for the response.  I don't think I've ever heard of CrOCl2, and we're only allowed to use reagents we know, though...  Does anyone have other suggestions?  Until then I'm going to keep working at it

[macman104]

Hi Yarr, thanks for the response.  I don't think I've ever heard of CrOCl2, and we're only allowed to use reagents we know, though...  Does anyone have other suggestions?  Until then I'm going to keep working at it

Surely if you are learning the mannich reaction you're able to use other reactants.  If not, all the CrO2Cl2 does is what the first 2 steps of my synthesis does:  chlorine water, then oxidation of the alcohol to a ketone.  Which is where you are at for step 2 of Yarr's synthesis.

[Rico]

Hello

I'm not quite sure what it is you're discussing here but one thing I got out of it was that you needed to synthesise cyclohexanone from cycloheptene and I have a suggestion on how to do that (see jpeg attached). Ozonolysis of cycloheptene and workup with hydrogenperoxide to the diacid. Esterification and treatment with base giving via a claisen (dieckmann) condensation a beta-keto ester, that after hydrolysis can be decarboxylated to give cyclohexanone.

Rico