BOD513 - 21-8-2018 at 14:26
Hey all,
I’m trying to convert the unsaturated carbons in butadiene rubber to vicinal diones by oxidation. I’m considering direct oxidation of the double
bond with permanganate, but the yields I’ve found for that seem low at between 40-80%, which makes sense because I’m sure it’s hard to control
it enough to give one oxidation product. I’ve also seen selenium dioxide used to synthesize diketones from alkenes but due to availability and
selenium-grossness I’m not sure if that’s an option. I’m also thinking about brominating or dihydroxylating and then oxidizing that. Does anyone
have any advice on how to do this in a way that would give high yields?
draculic acid69 - 23-8-2018 at 20:55
Maybe using hbr to get what I would presume to be a mix of 1,3 1,4 and 2,3 dibromo butanes and isolating the desired isomer followed by sodium
hydroxide sudstitutiun of the bromos with OH groups followed by dichromate oxidation to the aldehyde you were looking for.I think I have read this
reaction works differently when light and heat are used compared to cold and in the dark.by different I mean gives different isomers as main products.
No experience or references just what I've read elsewhere about butadiene.hope it helps.
Just realized you were talking about polybutadiene and not 1,3butadiene.not sure how that would work in the polymer form compared to the starting
material.
[Edited on 24-8-2018 by draculic acid69]
BOD513 - 24-8-2018 at 12:28
Thanks for the response. From what I’ve read crosslinking can be a problem when trying to -OH substitute halogenated polymers, but the yields I’ve
seen for direct permanganate oxidation are so low that bromination-substitution-oxidation might be better in the end anyway. For lack of a better
option I’ll try both when my order of unvulcanized polybutadiene comes in.