[I_do_smart_sometimes]

Would greatly appreciate any tips on removing triphenyl phosphine oxide. My product contains a diothioketene acetal and an enol ether as the two major functional groups. I have attempted crashing out the oxide in cold (-78 - 0) hexane and cold ether. Column separation wasn't successful as it looks like my product has a similar R factor to the phosphine oxide. I would like to exhaust my options here before moving onto a julia olefination.   

[rolnor]

If I would try to crystalize I would do it in roomtemp and give it time. You can try different solvent systems for the chromatography, maby you get lucky find one that gives separation.

[TheUnassuming]

The first thing I would try is just using different mobile phase combinations to see if you can get separation.  What are you currently using?

Last ditch I would start looking at different crystallization conditions, hexane/ether and benzene/cyclohexane are the two main ones I think to get the OPPh3 to crash out.  When you tried the hexanes/ether route, did you compound just co-crystalize and thats why it didn't work?

You might search the literature as well for a metal that chelates the OPPh3 and makes it filterable.  I can't remember what metal/ligand it is off hand or the reference for that matter, but worth a search to find it while you are screening TLC conditions.

[I_do_smart_sometimes]

I've used two different mobile phases. a 1:6:13 mixture of DCM:Ethyl acetate:Hexane and then a 1% Diethyl ether in Hexane. The 1% looked like it separated well on TLC, but the oxide still stuck to my material. It could just as well be that I needed to use a longer column, but I did not have enough after my second column to attempt that.

Currently using neat solutions to crash out the oxide. I have not attempted a mixture yet. I also thought a metal would help pull it out, but I want to keep that as a last ditch effort.