Окисление пропенилбензолов перуксусной кислотой.

1. Классическая процедура

* Peracid:

- 1650ml of Glacial Acetic Acid
- 325ml of 30% H2O2
- 5ml of H2SO4
- Olefin:
- 500ml Acetone
- 325g of Isosafrole

- Solvents:
- 7500ml of Water
- 1500ml of DCM
- 600ml of MeOH
- H2SO4(15%):
- 525g(285ml) of Concentrated H2SO4
- 3215ml of Water

* Wash(s):

- 1250ml of Water
- 1250ml of NaOH 5% solution

* Drying:
- 50g of Anhydrous MgSO4

* Distillation:
- 100ml of Cooking oil to prevent scorching

Procedure:

- Mix the peracetic acid chemicals together in an appropreate sized flask(3L+), swirl or stir solution until thouroughly mixed and let stand for 12 hours.
- Combine the olefin chemicals and place into the freezer to chill.
- Bring the peracid solution down to 5C with the help of an ice/salt/water bath.
While magnetically stirring this solution sitting in the ice bath, add the now chilled olefin solution to the peracid solution at such a rate that the mixture stays below 40C. After all of the olefin has been added, let the solution stir for 16 hours, letting the ice bath melt away and the solution come to room temperature on it's own.

- After the 16 hours of stirring has elapsed, flood solution, or pour solution into 7500ml cold water and mix thouroughly. After which time one extracts this mixture with 3 X 500ml DCM. The extractions are combined and the solvent removed via distillation to yeild a thick, dark red syrup.

- This syrup is taken up with 600ml MeOH and added to the 3500ml H2SO4 solution and lightly refluxed for two hours. After which the flask is cooled under running water and/or the use of an ice bath, do not proceed until solution has reached room temperature or lower.

- Using a large sepratory funnel or by simply pouring off the acid layer collect the dark bottom layer BEFORE extracting this mixture 3 X 400ml DCM(you did reuse the DCM from the first extraction, didn't you?). Combine the extracts with the dark layer which was first collected and proceed.

- Wash this dark mixture of ketone/solvent with 1250ml of water, then with the 1250ml of the 5% NaOH solution which was made previously. Please note that the seperation with the second wash will be difficult to see, therefor the use of a light is favorable to determine the different layers(similar to the first seperation of a Benzoquinone wacker wash).

- Dry organic phase over/thru 50g of anhydrous MgSO4(made by baking epsom salts at 300C for a couple of hours, let cool, then grinding into a powder) making sure to filter off the MgSO4, and washing the filter cake with a small amount of DCM. The solvent is removed and kept for a later run, the resulting residue is Combined with 100ml of vegitable cooking oil and distilled under vac to yeild ketone(>200g).

Oh yeah, I forgot, some amounts were changed with out a change in yeild. I think SWIM said that the amount of GAA could be reduced to 1500ml and the resulting glycol can be taken up in 500ml of MeOH and refluxed with 2500ml of H2SO4(15%)

Please remember that the peracetic is explosive, so please try to treat it with some respect (caution)...

2. Улучшенная процедура от Chromic.

I watched a gray-haired old man with black-trimmed glasses add 100mmol alkene (14.8g), 150ml DCM to a 500ml flask. 76.1g of 15% peracetic acid (2) buffered with 3g sodium acetate (3) was dripped in over 10 minutes. A mild reflux was present for 5 minutes or so. Then subsided. The reaction was left to stir as the protagonist went off, apparently, into a deep sleep.

Perhaps, five or six hours later the main character awoke quite restlessly from his deep sleep, and there I observed him slowly add 150ml of 10% Na2CO3 (NaOH would work too, but Na2CO3 was apparently less expensive to the old man), allowed it to stir, transferred to a sep funnel, drained off organic, then repeated.

The DCM was distilled off (4), 18.8g of oxidation product remained (1), and the oxidation product was put into a standard rearrangement technique.

25ml MeOH were added along with 120ml 15% H2SO4. This was heated to reflux with stirring for 2hrs, extracted 3x with 20ml DCM, washed 2x with 5% NaOH.

After rearranging, a simple distillation was setup, the DCM distilled, then vacuum was applied and this yielded 0.3g clear and colorless forerun at 148C-168C (~5 drops) (likely anethole) and 9.2g slightly yellowish PMP2P at 172-76C. (56.1% yield)

I watched the old man smile with a slight chuckle as I came to consciousness, and decided to quickly jot down some these notes that he telepathically relayed:

(1) if it was solely the glycol this 18.8g of glycol would be 103mmol, which is impossible, and upon no-vac distillation the distillate smells of acetic acid (but the oxidation product does not have this smell), so he had a good yield of the acetate ester as well. So the sodium acetate buffered version does not produce the epoxide, and in other trials it also appears that adding bicarbonate doesn't allow the epoxide to be formed either... but perhaps some other dreamer will get it to work. Maybe it would be best to try a stronger base like sodium carbonate for the buffering.

(2) 38.4g 35% H2O2, 36.9g acetic acid, 0.8g H2SO4 can be used to prepare 76.1g of 15% peracetic acid. This solution must sit for, preferably, 2-3 days. In fact, he had prepared a large stock solution in advance so he only had to do this once-an old man, but a smart old man. He DID NOT BUFFER his stock solution.

(3) A 2x molar excess of sodium acetate with respect to the sulfuric acid content in the peracetic acid was used to buffer the solution before addition to the flask.

(4) The internal temperature of the flask hit a temperature of over 100C, so I'm sure he distilled off all the DCM, this yield is correct.

(5) PMP2P sinks in water (rather than floats), smells nothing like licorice and tests positive to bisulfite.

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