Author Topic: Easy Oxidation of THF to GBL  (Read 31761 times)

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moo

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Second thoughts
« Reply #80 on: May 12, 2003, 03:02:00 PM »
The Fenton oxidation of THF to GBL involves both Fe2+ and Fe3+ species not least because it is a catalytic amount of the iron salt. Now after checking the references I have on hand on decomposition of peroxides by iron, they say that hydrogen peroxide is decomposed by acidic solutions of Fe3+, but say nothing about THF hydroperoxide (Acc. Chem. Res. 8, 125 (1975)). On the other hand the ref. that explicitly discusses the decomposition of THF hydroperoxide by metal salts mostly discusses the reaction with Fe2+ (Bull. Chem. Soc. Japan, 36(5), 527-30 (1963)). So I'm not so sure anymore because there is a risk I don't want to get blamed for if the information was incorrect. It could possible that undecomposed hydroperoxides remain after the reaction, but I guess it is unlikely. These free-radical reactions are chaotic, hard to predict, produce various byproducts and considering the possibility of an explosion it might just be wiser to add a little ferrous sulfate later on to take care of the bogies.

Distilling the reaction mixture by itself would be at least partly a steam distillation... I remember it is a method that has been used in isolation products from horrible reaction mixtures containing iron salts, yes it is really a dirty reaction. I think adding FeSO4, distilling, extracting the goodies from the distillate with DCM, drying the DCM, evaporating the DCM and then vacuum distilling the GBL from the residue for further purification would be in order.

Bwiti

  • Guest
>isolation products from horrible reaction...
« Reply #81 on: May 12, 2003, 11:45:00 PM »
>isolation products from horrible reaction mixtures >containing iron salts, yes it is really a dirty reaction.

  Probably won't be as messy as with iron/nitrotoluene. ;)