[bimmer3]

What is wrong with this synthesis? And what would I need to change to get the major products? / is it possible to do this in one flask?

[bimmer3]

There is a benzene on the end of the product, if you click on the picture you get the whole thing.

[discodermolide]

You can do everything in one pot, not advisable as the side products you get may also react.
Why use acidic KMnO₄ for the first oxidation? There are easier and better ways to oxidise ketones.
The product after the aldol condensation can also react on the other side to give the bis-aldol product.
Your final product is a hemi-ketal and will probably revert to the ketone.

[bimmer3]

thanks for clearing all of that up. I used that oxidizer cause it was my only choice, but i kept it at a low enough temp so it wouldn't go nuts on the ketone.

[discodermolide]

So what was the yield of the oxidation reaction?

[bimmer3]

Not sure, in the literature its very high.

[discodermolide]

OH, I got the impression you had actually done the synthesis, or part of it.

[bimmer3]

Would a michael addition happen at the Beta position? So the result would be the dialdolcondensated ketone with di-ether at the beta position?

[discodermolide]

It could, but the anion may be a bit sterically crowded for this.

[bimmer3]

So what would be the major product. The dialdocondensated ketone? I actually did end up doing this synthesis but many items in the lab are not working so identification of products was next to nill, but my end product is a transparent yellow colored liquid with a strong (slightly fatty and sweet) aroma. Seems like there is a fair amount of ether. I did had a pretty large amount of NaOH.

[discodermolide]

At a guess it may be the following.

[bimmer3]

Also a sample boiled at ~86 °C, but i doubt that tells me much, since their would be such a mixture of products.

[discodermolide]

Well your description of the reaction and the products does not readily lend itself to easy identification.

[Archer]

I can't see this working to form the hemiacetal particularly well.

Unless hemiacetals are cyclic (lactols) they are notoriously unstable (in my experience) the final molecule would quite happily eliminate water to form a double bond which is favoured because it is conjugated to the benzylidene.



Could you provide the literature reference and maybe the experimental details?

[bimmer3]

What could I do to the 2,5-dibenzalcyclopentanone that would be a good yield?