Congratulations! You're one step ahead of where I am, to where I want to be. I love dmmda-2 and I ought to get off of my butt, get a good vacuum pump and pursue it.
I wouldn't have bothered recrystallizing your isodillapiole. It sounds fine. Vacuum is only necessary during the beginning of the isomerization. Once the water is removed, everything is a go. (there might even be other ways around this, such as using KOH in 99% IPA and distilling off the IPA... but why think about these methods as you have to use the vacuum anyways to do the reflux.
I'd always bisulfite test your ketone before you prepare your oxime. If you can't get the bisulfite to form crystals as I talked about in other posts, you haven't a chance with the oxime formation. It's a great priliminary test that involves almost no reagents (try 5ml sat K or Na (meta)bisulfite in water, and 0.2ml of ketone). The test tube should fill with white crystals. If you don't see white, that likely means there's a few impurities in the ketone. For example, the last run I did with mdp2p the bisulfite was yellowish orange. I went to prepare the oxime and it was a heavily viscious oil that did not crystallize when left to stand overnight in the freezer. In the past with tma-2, I just went on to reduce it and I got some yields! BUT... you can do better than me. No excuses.
>a) Would using the slightly oily crystals from the previous
>recrystallization (described earlier) affect the performic
>drastically (as opposed to having purer iso-dillapiole).
I doubt it. If it was relatively pure, the performic will go after the isodillapiole before the dillapiole.
>Is the red organic layer experienced with iso-dillapiole a sign
>of a problem or is it correct?
Color change to yellow or orange is common with epoxidation of propenylbenzenes, and I think is a sign of success.
>Should the formic / H2O2 be cooled during mixing or will this cause a problem?
Leave it for an hour like the writeup says, no cooling.
>Is it likely that the ketone was too impure in the first run to
>get crystals of the oxime?
Absolutely. With the tosic acid mdp2p I made (without further purification), I'd guestimate it was fairly pure. (my guess, and just a number from a hat, 80%+) But it wasn't pure enough to form the oxime. You really should distill it with a short fractionating column.
>Or in fact non-existent?
That I very much doubt. Use the bisulfite test to tell.
1) If your bisulfite fills with white crystals, it's likely quite pure. BRAVO!
2) If the crystals are off colored, then there's a small bit of impurity. Fine for amination, risky with oxime formation.
3) If the oil turns to small bits of chicken fat, then your ketone is pretty damn impure. Distill again!
4) If there's no reaction after 1-2 hours, then there's likely zero ketone.
>e) How necessary is a column for ketone distillation
I'd say it's pretty damn important, but if you collect relatively narrow fractions (5C range) with simple distillation I'd say you're going to get success.
>f) When insulating a column, it seems dangerous to clamp the flask from
>outside the insulation - is it normal to leave the flask neck un-insulated?
I insulate the necks with glasswool and clamp around the glasswool. Caveat emptor. I often don't know a normal intelligence quotient from Ally McBeal's dress size.