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Benzaldehyde + MEK acid catalyzed aldol

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I am prepared to do the subject reaction with Bayer Villager oxidation to P2P. Where I am now I have no access to a library only the internet for references. Does anyone have anymore details on this procedure? I feel the sketchy details in Post 245942 (twodogs: "New method for P2P", Novel Discourse) are fraught with pitfalls and I sure don't want to waste my analytical grade $80 a liter PhCHO. Also I have been searching the internet for other catalysts other than Hydrogen Chloride which would be suitable for this type reaction to no avail. Any references or pointers would be highly appreciated. The Organic Reactions volumes referenced don't seem to be available on-line and the Patents referenced aren't very helpful. Anyway I will try it on a small scale soon and will let you all know how it turns out.

Sketchy details?? Jesus Christ much detail do you want? If you follow the procedure exactly as I have mentioned you will get a result.

OK, Two Dogs thanks for the encouragment. Perhaps sketchy was a poor choice of words. So I assume you have had success with this reaction. It does seem fairly simple to do. Apparently a little H2O is not detrimental to the condensation product yield as they performed it in an open beaker at freezing temperature. This puzzled me somewhat as water is eliminated and usually I used a Dean Stark tube or at least a drying tube in a sealed system for similar PhCHO condensations. Also I wonder if the relatively low yields are partly due to doing atmospheric distillation. At those high temps it seems a lot of decomposition could occur. I will try a test batch tomorrow and see if it will crystallize after removing the excess MEK. If you have done this reaction could you share some more thoughts? I want to scale it up and think the oxidation step could get by with way less MeCOOH.

Bio...yes I have had sucess with this reaction but I felt that 35% was too low for me. The aldol condensation part is very easy and as I mentioned can be done with refluxing conc. HCl or with H2SO4 but you get the best result with dry HCl. With the oxidation part, I would use peracetic acid or performic acid if I were you as the perborate makes for a messy workup. If you use less Acetic with the perborate you will end up with such a solid mass that you won't be able to stir it. I don't do this shit any more but have a look at this site from time to time but I know two another ways to the ketone from the unsaturated ketone that is formed from the aldol condensation. The unsaturated ketone can be oxidised with NaOCl to give the alpha- methyl cinnamic acid. This can be decarboxylated to give phenyl propene that can be worked up with performic etc or the methyl cinnamic can be oxidised with oxone and the resulting epoxy acid decarboxylated to give the ketone. I was looking at these reactions when I figured out that the Baeyer-villager worked as well and that seemed easier. It is a pity you don't have a library handy as I think that the Baeyer-Villager would work much better with a catalyst.

question for two dogs.what strength peracetic would you recommend for the oxidation?would 30-35 %work? viki


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