Sciencemadness Discussion Board

Sesamin

detritus - 6-5-2008 at 16:13

When raw sesame seed oil is washed with acetone plus water (US2467904) the potent antioxidants sesamin and sesamolin can be extracted without damage to the remainder of the oil.

I know how much people love antioxidants, so I decided to post interesting structure here.




Sesamolin can be hydrolyzed to sesamol in aqueous alkali, as a side note.

Sesamol:

organometallic - 8-5-2008 at 08:58

Ok so sesamol has a pretty interesting shape.. to me anyway. I want to know, would it be possible to replae the phenol OH group with a methyl group, possibly with 1-iodomethane? If so, that would produce 3,4(methylenedioxy)toluene, which I bet could be oxidised similarly to methyl benzene to produce piperonal... the hunt for vanilla flavourings has taken an interesting turn..
Anyone care to lend insight? :)

methoxy

Tsjerk - 8-5-2008 at 09:19

If you would react sesamol with iodomethane you would get the methoxy, not the methyl. You would have to react the sesamol with HI to change the hydroxy for a iodine, and react that with something to get to the methyl.

organometallic - 8-5-2008 at 10:12

"If you would react sesamol with iodomethane you would get the methoxy, not the methyl. You would have to react the sesamol with HI to change the hydroxy for a iodine, and react that with something to get to the methyl."

Can anyone confirm that this would work? Also, anyone have any idea what "something" would react with 3-4(methylenedioxy)iodobenzene to produce 3,4(methylenedioxy)toluene?

This seems fairly promising..

12AX7 - 8-5-2008 at 10:54

Sounds like a classic Grignard.

[Edited on 5-8-2008 by 12AX7]

organometallic - 8-5-2008 at 11:13

Haha! Shit, i'm blind. Thanks.

Klute - 8-5-2008 at 11:17

HI reduction would cleave the methylenedioxy- long before iodinating the cycle... Tosylation and subsequent reduction of the tosylate (LAH, NaBH4, NaBH3CN, H2/Pd/C, etc would give 3,4-methylenedioxybenzene.

The NaBH3CN procedure is for alkyl tosylate. I'm not sure if it can be applied to aryl tosylates, you would need to check that..

[Edited on 8-5-2008 by Klute]

Bolt - 8-5-2008 at 12:52

I thought that it is nearly impossible to remove a hydroxyl group from a benzene ring. I know that you can replace a halide with an ~OH if there's a meta(?) deactivating group. Aryl alcohols don't react the same way aliphatic alcohols do...

stoichiometric_steve - 8-5-2008 at 14:03

Quote:
Originally posted by KluteTosylation and subsequent reduction of the tosylate (LAH, NaBH4, H2/Pd/C, etc would give 3,4-methylenedioxybenzene.


and then you could just buy catechol and methylenate that. avoids extracting huge amounts of sesame oil... ;)

Klute - 8-5-2008 at 22:42

Totally agreed! But who want's piperonal in the first place :D And as Bolt mentionned, this could not work on phenols, I have found no direct examples (but didn't search much), so it's just a suposition..

Now what could be done is ortho-formylation of sesamol, followed by methylation of the phenol. The benzaldehyde would be a precursor to MMDA-2 without the need of a Vilsmeyer... The Mg/(HCHO)n formylation should yield the right isomer. This could be higher yielding than the original procedure.

not_important - 9-5-2008 at 05:33

If you look at sesamin and pay attention to those benzilic and tertiary hydrogens, you might come up with a method to selectively attack those to give handholds that end up letting you cleave the side chain and get (two) ArCHO or ArCO2H.

But at 5 to 10 parts per thousand, you'll need a lot of sesame oil, and a bunch of messy extraction work.

LSD25 - 12-5-2008 at 02:07

Here is something interesting you can do with it if you can find it, but...

http://jchemed.chem.wisc.edu/Journal/Issues/2006/FebACS/ACSS...

Now what would you describe that reaction as? It ain't a Claisen rearrangement, because it doesn't use an ether, it is not a Fries rearrangement because it doesn't use the carboxylic acid, rather it uses the dimethylbutenal, which attaches itself ortho to the phenol, doesn't bother the MD, and looks like it might be of some use (I like the way they describe the entire thing in such detail - even I couldn't fuck it up - bet I could).

Oh yeah, Klute, is this what you were thinking of?

Attachment: PdC.DEA.Hydrodeoxygenation.phenols.pdf (818kB)
This file has been downloaded 3063 times

Saerynide - 12-5-2008 at 12:17

Quote:
Originally posted by not_important
But at 5 to 10 parts per thousand, you'll need a lot of sesame oil, and a bunch of messy extraction work.


You can buy Sesamin supplements I think ;)

ChemistryGhost - 26-7-2012 at 23:04

Quote: Originally posted by organometallic  
"If you would react sesamol with iodomethane you would get the methoxy, not the methyl. You would have to react the sesamol with HI to change the hydroxy for a iodine, and react that with something to get to the methyl."

Can anyone confirm that this would work? Also, anyone have any idea what "something" would react with 3-4(methylenedioxy)iodobenzene to produce 3,4(methylenedioxy)toluene?

This seems fairly promising..


I don't know what "something" would react with 3-4(methylenedioxy)iodobenzene to produce 3,4(methylenedioxy)toluene. However, I can say that sesamol can react with methyllithium under certain lab conditions to produce 3,4-methylenedioxytoluene. :cool:

ctrlphreak - 21-8-2012 at 19:41

This was all discussed by Klute, nothing original.

Sorry for the post.

[Edited on 22-8-2012 by ctrlphreak]