piperonylic acid

[Jan1983]

Hi guys, again piperine piperidine piperic acid and so on,

here a question:

Can "piperonylic acid or the alcohol" also be used as a source for piperonal ?

Greets

[OB1KNoBee]

Don't think so... stick to the sure thing.
GOOD GOOD

[PrimoPyro]

The alcohol can be oxidized to the aldehyde (which is piperonal) and technically LAH could reduce the acid (an ester of it) to the alcohol, ready for oxidation. But the practicality of this is very small.

The piperonyl alcohol would be a good source if it was cheap for you to get.  

                                                    PrimoPyro

[Jan1983]

The alcohol:

100 g   =  45€

cheap enough ?

what can be used to oxidise the stuff ?? KMnO4 ? H2O2 ?

anyone has ref's ?

[Antoncho]

Fe(NO₃)₃




Antoncho

[PrimoPyro]

We so very rarely here that tone from you, Antoncho.  

As Antoncho says, ferric nitrate is the known method here. I bet cupric acetate with ammonium nitrate oxidation would work as well without overoxidation. It is a very gentle reducing agent.

KMnO4 will very likely yield the carboxylic acid. I don't know how H2O2 would fare at all, personally. I myself would stick with ferric nitrate since it has been documented here.

Reduction of the acid ester with LAH to the alcohol, then oxidation to the aldehyde, is not worth all the effort just for some piperonal. LAH is damn expensive, and should be saved for more important steps, i.e.reduction of nitrostyrenes etc.

                                                 PrimoPyro

[Antoncho]

I forgot to mention that for those who, unlike swim, aren't financially challenged , PtO₂ and oxygen is the best possible way. A very general and selective/high-yielding oxidation.


Antoncho

P.S. Primo:  

[terbium]

I bet cupric acetate with ammonium nitrate oxidation would work as well without overoxidation. It is a very gentle reducing agent.
Any reputable references to this procedure? I was under the impression that it was just someones pipe dream.

[Rhodium]

The references I have seen on that oxidizing system deals with the oxidation of hydroxyketones to 1,2-diketones - I don't know its scope outside this.

[PrimoPyro]

My references for that would be in TFSE, in posts that represent it as fact rather than novelty. I hate when TFSE is wrong or incomplete.  

                                                PrimoPyro