The Vespiary

The Hive => Serious Chemistry => Topic started by: Dr_Heckyll on August 03, 2002, 08:25:00 PM

Title: Sensitivity of methylenedioxy group
Post by: Dr_Heckyll on August 03, 2002, 08:25:00 PM
How sensitive is the methylenedioxy group in a simple molecule like methylenedioxybenzene to acid-catalyzed splitting? Will it be split by methanesulfonic acid or acetic acid in a water-free system and prolonged reflux?


Happiness, health and wealth through chemistry...
Title: naaa don't think so. HI(aq) will do BF3 will also ...
Post by: hest on August 04, 2002, 10:06:00 AM
naaa don't think so.
HI(aq) will do BF3 will also (or most other lewis acids)
Title: Re: Sensitivity of methylenedioxy group
Post by: Flip on August 04, 2002, 07:10:00 PM
On a similar note, relating to my current project;

What would be the effects of ozonolysis on a methylenedioxy benzene? Assuming of course the standard controlled conditions are met, the benzene ring is not attacked, and that a dilute O3/O2 mixture is used?  Would the methylenedioxy group even make a difference from the results of an ozonolysis on plain ol' benzene?  This may seem obscure but to me it is quite pertinent.
Title: By instinct rather than by knowledge I would be ...
Post by: Dr_Heckyll on August 04, 2002, 07:51:00 PM
By instinct rather than by knowledge I would be worried that the product would be something like












Molecule: (https://www.the-hive.ws/forum/faq.pl?Cat=#applet)

bdo ("O=C2OC1=CC=CC=C1O2")


Happiness, health and wealth through chemistry...
Title: Unstable
Post by: PrimoPyro on August 04, 2002, 07:53:00 PM
This compound is an acid anhydride of carbinic acid and catechol, and would likely hydrolyze in moisture to carbon dioxide and catchol, would it not?
Title: please forgive my ignorance
Post by: Flip on August 04, 2002, 08:10:00 PM
How exactly would O3 attack the methylenedioxy to form this compound which hydrolyses to CO2 and bezenediol?
Title: It Doesn't
Post by: PrimoPyro on August 04, 2002, 08:19:00 PM
That compound would not be formed.
Title: Halogenating Reagents
Post by: WizardX on August 07, 2002, 06:18:00 PM
Halogenating Reagents: PCl3 or PCl5, PBr3 etc... will halogenate the methylenedioxy ring with halogens.

Reference? Must find it again? Stay tuned!

Title: methylenedioxy ring chlorination
Post by: Rhodium on August 07, 2002, 07:27:00 PM
It's in

http://www.orgsyn.org/orgsyn/prep.asp?prep=cv2p0549 (http://www.orgsyn.org/orgsyn/prep.asp?prep=cv2p0549)

Title: Thanks Rhodium!
Post by: WizardX on August 09, 2002, 07:05:00 PM
Ahh, yes! That's one. There is also another, in the JOC, I think??
Title: Ozonolysis
Post by: Antoncho on August 25, 2002, 09:06:00 AM
There was a ref (on the Hive? i think) that described ozonolysis of piperic acid to piperonal - so i think it's not much of a problem, of course having the exact conditions at hand is strongly recommended.



Antoncho
Title: ozon etc
Post by: GC_MS on August 25, 2002, 09:51:00 AM
As far as SWiM remembers, O3 is active on olefins as isosafrol, where it oxidizes the propenyl pi-bond and converts the propenylbenzene analogue to its benzaldehyde derivative (i.e. isosafrole -> piperonal).
Stability of the methylenedioxybridge: be sure to keep it away from Lewis bases as AlX3 (X=Cl, Br, I) and all those other stuff that can be used for the O-demethylation of methoxybenzene derivatives (such as vanillin, isoeugenol etc). Don't have the exact references and patents handy, but SWiM remembers they are used for the synthesis of 3,4-dimethoxybenzaldehyde and 3,4-dimethoxyphenylpropene from piperonal and (iso)safrole respectively.
Doped(TM) since 19.... euhm... a long time  :)