If you are distilling ketone and have it up to a vigorous boil around ~102-110C, and decide to break down your glass and collect out a fraction quickly, your distillate will turn into tar upon disconnection of the vacuum source and quick repressurization.  I did this once, and ever since then I have made sure to remove the distilling flask from the oil bath and allowing to cool before collecting fractions.  You can't add acetone to a flask that is currently 120C, and by the time it cools down to 50C you have a hardened lump at the bottom.

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All paths are the same: they lead nowhere

BTW, the yield of bisulfite complex from the 1 gram of clean ketone was 1.6 grams of dry, bright white powder.
So, you are claiming a quantitative yield:

(178+104)/178 = 1.6

Awesome! That's a 95%+ yield if your crystals are absolutely dry (1.6g / 1.67g). Now, MaDMAx, just tell me another solvent to use other than ether to get the bisulfite adduct to form from impure ketone, and I'll love you forever!

I suppose I should be doing those experiments myself... but I'm being a lazy bee.

for those of us less fortunate than most, this procedure verifiably can be used(if done correctly) to circumvent fractional distillation of ketone.
I UTFSE and have read of one account where MDP2P was purified via bisulfite procedure and subsequently aminated after washing with alcohol and the result after a Nitro Al/Hg reduction was %60 yeild, the usual result of impure ketone (ie. peracid produced and washed with NaOH, water) was anywhere from
%10-to nothing.
So after careful research of case examples, this is feasible if need be for those of us in a pinch.
Although classical purification methods are less tedious.
I'm not trying to deliberatly take shortcuts but it's nice to calculate all of the possibilties, rather than assume to know everything needed to know.

I would think using excess water and a hard shaking would allow the adduct to seperate from the alkene.  I would also add that the adducts from impure usually has a mixture smell of iso and glycol. however Swim couldn't get crystals to form then either, But not much effort was applied.
VL_

Ok. I took 0.2ml pmp2p, 1ml DCM and stirred with 5ml bisulfite. It stirred for a day with no adduct forming. I boiled off the DCM and the beautiful white crystals formed. I then added DCM to the test tube. The bisulfite adduct was not soluble in the DCM.

Any other ideas? I don't have any substancial amounts of ether around.

Stirring is usually not good enough. You have to shake the shit out of it O2 wacker style.
Try toluene, or xylene. And use less bisulfite solution.

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I'm not fat just horizontally disproportionate.