Sciencemadness Discussion Board

theoretical principle of the olefin auto-oxidation

postart - 29-8-2010 at 10:22

Hey, sorry for forgeting about references and such last time. I think this should be better. According to Chemical Abstracts 97, 23367 (1982), heating isosafrole in DMSO to 100-120°C for an unspecified amount of time results in autooxidation of the isosafrole, forming MDP2P as the major product, but the precise yield is also unspecified in the abstract. The details for this synthesis has been published in Yukagaku 31(4), 222-225 (1982) (ISSN: 0513-398X). As the reaction is labelled as an "auto-oxidation" I suppose that it comes from the air, or else they would label the DMSO as the oxidant (and dimethylsulfide would form).

My theory goes as follows:

You dissolve for instance a certain amount of isosafrole in DMSO and introduce a stream of dry air into the mixture. The oxygen will form an intermediary complex with isosafrole, which will decompose into piperonal and acetaldehyde. These two aldehydes, however, are subject to auto-oxidation as well! Perbenzoic acid can be formed by introducing oxygen in a solution of benzaldehyde in acetone. Acetaldehyde will result in peracetic acid while piperonal will yield 3,4-methylenedioxy perbenzoic acid. The actions of peracids on alkenes as isosafrole is well known. And this is where the fun starts . The epoxide (formed by the reaction between isosafrole and peracid) can rearrange to a zwitterion (positive charge on C1 and negative charge on O of the side chain), which on itself is a substrate in a Pfitzner-Moffatt oxidation reaction. And voila, there you have your MD-P2P. I must add that the zwitterion I just talked about can also rearrange to MD-P2P spontaneously. Thaughts?

Quantum_Dom - 29-8-2010 at 11:02

The journal you are referring (Journal of Japan Oil Chemists' Society) is freely available to anyone online. May I suggest next time that you do a little bit more effort in looking for references. Quotes are good but if you can get the actual paper its way better.

Now the least you could do, if you want people to pay attention, is to translate the relevant part in the paper and highlight them in your thread.

Attachment: Autoxidation of Benzene and Phenolic Compounds Containing Isopropyl,.pdf (551kB)
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[Edited on 29-8-2010 by Quantum_Dom]