Author Topic: piperonylic acid (Read 2600 times)

Jan1983 · « **on:** June 17, 2002, 11:33:00 AM »

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 · « **Reply #1 on:** June 18, 2002, 01:39:00 AM »

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

GOOD GOOD

PrimoPyro · « **Reply #2 on:** June 18, 2002, 04:56:00 AM »

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 · « **Reply #3 on:** June 18, 2002, 07:33:00 AM »

The alcohol:

100 g = 45€

cheap enough ?

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

anyone has ref's ?

Antoncho · « **Reply #4 on:** June 18, 2002, 11:35:00 AM »

Fe(NO₃)₃

Antoncho

PrimoPyro · « **Reply #5 on:** June 18, 2002, 02:25:00 PM »

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 · « **Reply #6 on:** June 18, 2002, 06:28:00 PM »

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 · « **Reply #7 on:** June 18, 2002, 07:11:00 PM »

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 · « **Reply #8 on:** June 18, 2002, 07:42:00 PM »

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 · « **Reply #9 on:** June 18, 2002, 08:51:00 PM »

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

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