Author Topic: New method for P2P  (Read 389856 times)

0 Members and 1 Guest are viewing this topic.


  • Guest
Baeyer-Villiger with potassium peroxodisulfate
« Reply #20 on: April 04, 2004, 05:43:00 PM »
Rearrangement of aliphatic primary, secondary, and tertiary alkyl hydroperoxides in strong acid
Norman C. Deno, Wilbur E. Billups, Kenneth E. Kramer, and Robert R. Lastomirsky
Journal of Organic Chemistry, 35, 3080-3082 (1970)

The interesting question being: if there is potential for the double bond to react (epoxide for example), is it going to be a problem?


  • Guest
Thanks for obtaining this article, Moo.
« Reply #21 on: April 04, 2004, 07:15:00 PM »
Thanks for obtaining this article, Moo.  I know a bee who is going to be very gratefull.

The interesting question being: if there is potential for the double bond to react (epoxide for example), is it going to be a problem?

This can be a problem indeed, as shown in:

   (page 5/18).  

Another (hypothetical) problem I forsee is that, when the enol ester cleaves & rearranges to the P2P, that the P2P might undergo the Baeyer - Villiger reaction too.  But since the reaction proceeds in minutes, I think kinetics is on our side.  Don't think the benzyl group would migrate very rapidly too.    <--- don't take this info in this paragraph for granted, the Baeyer - Villiger reaction is not my speciality.

For the future experimentator's notice, I think it could be worth to try out the premade persulfuric acid 'dry' Baeyer - Villiger reagent too, for which preparative details (& solvents) are given in the same article (page 10 / 18).


  • Guest
Redox time
« Reply #22 on: April 22, 2004, 07:31:00 AM »
The article says that solutions of K2S2O8 in 20 - 60 % H2SO4 are advantageous for the Baeyer-Villiger oxidation of ketones.

Caro's acid (H2SO5 ) is a powerfull oxidant.  The ketone of the 2-acetyl-propenylbenzene gets protonated in the acidic medium and the peracid reacts with the ketone, whereupon the propenylbenzene migrates and the acetyl group is shopped off in the acidic medium  --> P2P.

Further in the article, is said: It was thus of some interest to find that solutions of K2S2O8 in 50 % H2SO4 gave quantitative yields of the Baeyer-Villiger products of a variety of simple aliphatic ketones.  The reactions were complete at 25 °C, and we cannot understand why this extremely simple procedure has not been utilized !!!

Caro 's acid is generated in situ by adding the K2S2O8 to aqueous sulfuric acid in the folliwing redox reaction:

ox: SO42- + H20  -->  SO52- + 2 H+ + 2 e-
red.: S2O82- + 2 e-  --> 2 SO42-

Or in other words:
H2S2O8 + H2O + H2SO4  -->  H2SO5 + 2 H2SO4

I think it could bee just as simple as that: just adding the 2-acetyl-propenylbenzene to a K2SO8 / H2SO4 solution.

Now, I have been informed that somebee wants to try out this reaction.

I guess the bee who PMed me for retrieving this article forfaited ... arghh: loyality  ::)


  • Guest
« Reply #23 on: April 22, 2004, 08:25:00 PM »
Would 3,4 methylenedioxy benzaldehyde react the same way too? My girlfriend brought me a heliotrope flower from her garden the other day and it struck me how similar it smelled to benzaldehyde...


  • Guest
Piperonal + MEK
« Reply #24 on: April 23, 2004, 03:19:00 AM »
Yes, as you can see here:

Post 487686

(Rhodium: "More MEK/Benzaldehyde condensation refs", Novel Discourse)

The yields aren't stellar though.


  • Guest
I seem to remember a patent about caro's acid...
« Reply #25 on: April 23, 2004, 04:28:00 AM »
I seem to remember a patent about caro's acid production. It said something about  pouring conc. H2SO4 into a solution of persulfate contained in a dewar flask. The resulting mixture was left alone for awhile resulting in 80% yield. When the same was done by mixing the solutions in regular glass, with stirring and external heating the yields were much inferior.


  • Guest
« Reply #26 on: April 23, 2004, 04:35:00 AM »
Here it is:

Patent US4049786

Process of preparing peroxymonosulfate
High strength peroxymonosulfate is prepared by adding concentrated sulfuric acid to a solution of a soluble peroxydisulfate whereby the heat of solvation of the sulfuric acid hydrolyzes the peroxydisulfate to the peroxymonosulfate; the temperature is controlled to provide a range of about to F. After about 15 to 45 minutes, the solution is cooled rapidly to about room temperature.


  • Guest


  • Guest
From document: Fast, high-temperature, acid...
« Reply #28 on: April 26, 2004, 06:57:00 AM »
From document:

Fast, high-temperature, acid hydrolysis, followed by chemical quenching will yield solutions of peroxymonosulfate

This is: Osmium 's procedure.

Strong acid [H+] > 0,5 M
S2O82- + H20  --> HSO4- + HSO5-

Now, there is substantial risk that the enol ether (I 'm practically sure of it) will be hydrolyzed is such acidic conditions (say 20 % H2SO4).  This, combined with an excess of oxidant HSO5- or with a faster hydrolysis than Baeyer-Villiger oxidation will result in Baeyer-Villiger degradation of the P2P.

This bee thinks it would be preferable to use the above mentioned 'dry' Baeyer-Villiger oxidant in acetic acid: transesterification will yield the same product, while hydrolysis can be the first step in further decomposition.

Or mabey after all, it would be preferable to just use peracetic acid like in the original articles   ::) .


  • Guest
Baeyer-Villiger on unsaturated ketones
« Reply #29 on: April 28, 2004, 11:05:00 AM »
I did some reading on the Baeyer-Villiger reaction performed on ?,?-unsaturated ketones and aldehydes (mainly in Org. React. 43, 251-798 (1993) and references found therein), and found out that the main problem with the reaction on compounds like R1CH=CR2COCH3 with straight-chain alkyl substituents is not that the product enol acetate undergoes further oxidation to the epoxy acetate - it is that the majority of the starting material undergoes epoxidation to the epoxy ketone (this doesn't happen if the R groups are tied together in an alicyclic ring though), and there is no way of stopping this side-reaction, only decreasing it by choosing the right oxidant. Unfortunately the best oxidants are really big molecules, such as peroleic acid (CH3(CH2)16CO3H) or hydrogen peroxide with benzeneselenic acids (Ar-Se-Se-Ar). The yields are more promising with the homologous ?,?-unsaturated aldehydes, R1CH=CR2CHO (in our case 2-methylcinnamaldehyde), but on the other hand that starting material is instead harder to synthesize.

Some references which extrapolate on this follows below. The article using benzeneselenic acids as catalyst can be found at DOI:


if you have online access to Tetrahedron.

About the Baeyer-Villiger oxidation of 2-Methylcinnamaldehyde with peracetic acid, achieving a higher yield than with the corresponding methyl ketone.

Recherches sur l'oxydation de l'éthyl-2-hexène-2-al et de quelques aldéhydes apparentés. III.
Oxydation de I'éthyl-2-hexène-2-al et de l'éthyl-2-hexanal par l'acide peracétique

C. Schaer

Helv. Chim. Acta 41, 619-625 (1958)

____ ___ __ _

Reaction mechanism and product distribution in the Baeyer-Villiger oxidation of analogs of our ketone of interest - 3-Methyl-4-Phenyl-2-Butanone - where either of the CH3 groups has been substituted by a phenyl group.

The Peracid Oxidation of Ketones. III. The Reaction of ?,?-Unsaturated Ketones with Peroxybenzoic Acid
By Tai Yokoyama and Fujio Nohara

Bull.Chem. Soc. Japan, 38(9), 1498-1500 (1965)

____ ___ __ _

Baeyer-Villiger oxidation of 3-Aryl-4-Phenyl-2-Butanone with Persulfate in acetic acid with catalytic sulfuric acid.

trans-1-Aryl-2-aroyloxyethylenes. Persulfate Oxidation of Chalcones and Chalchone Analogues
D.N. Dhar & R.C. Munjai, Synthesis 542-543 (1973)


  • Guest
Nice articles
« Reply #30 on: April 29, 2004, 06:34:00 AM »
Even though the yields will be low, it is nice to see that the peroxysulfuric acid oxidation works on unsaturated ketones.  Persulfate seems to be a rather usefull compound.  Osmium demonstrated that in

Patent US4146582

it can also be used to convert toluene to benzaldehyde  {unable to localize post due to technical reasons }

This P2P synthesis would be super easy, and rather not suspicious.


  • Guest
non-OTC method
« Reply #31 on: May 03, 2004, 12:08:00 PM »


  • Guest
Some further related references
« Reply #32 on: May 04, 2004, 01:22:00 PM »
Oxydation des aldéhydes ?,?-non-saturés par l'acide peroxoacétique
C. R. Zanesco

Helv. Chim. Acta 49, 1002-1012 (1966)


Baeyer-Villiger oxidation of ?-methyl-cinnamaldehyde with peracetic acid. Discussion of the reaction mechanisms at work, and the product distibution under different reaction conditions. Their best yield of P2P enol formate is 52%, and this is easily hydrolyzed to P2P by mere water.
____ ___ __ _

Synthesis of Heterocyclic Compounds from ?-Unsaturated 1,3-Diketo-esters.
Part II. ?-Substituted Styrylpyrazole- and Styrylisoxazole-carboxylic Esters

L. Rateb & G. Soliman

J. Chem. Soc. 1426-1430 (1966)


Preparation of various ring-substituted ?-methyl-benzalacetones from benzaldehydes and excess 2-butanone (MEK) with dry HCl gas at -5°C. With references to previous preparations.


  • Guest
Baeyer-Villiger on unsaturated ketones
« Reply #33 on: May 04, 2004, 03:29:00 PM »
The following article describes oxidation of benzylideneacetone to phenylacetaldehyde enol acetate with peracatic acid in acetic acid buffered with potassium acetate in 60% yield, also other unsaturated ketones relatively close to phenylacetone enol acetate are oxidised and "isolated in yields of 65-80%", 2-benzylidenecyclopentanone among them. What do you think, could the need for 90% hydrogen peroxide be avoided by use of UHP (urea hydrogen peroxide complex) here?

Reaction of peroxyacetic acid with a-aralkylidenecyclanones.
Walton, Henry M.
Journal of Organic Chemistry, 22, 1161-5 (1957).  Journal language unavailable.
CAN 52:29915  ISSN 0022-3263
The reaction of peroxyacetic acid (I) with a-aralkylidenecyclopentanones and a-aralkylidenecyclohexanones in AcOH media of different acidity resulted in the intrusion of an O atom between the CO and the methylidene C atoms, with the formation of new 5-enoic-5-hydroxy acid d-lactones and 6-enoic-6-hydroxy
acid e-lactones.  In the presence of massive amts. of KOAc further oxidation of the enol lactones under conditions of their formation was effectively suppressed.  a-Furfurylidenecyclohexanone (II) reacted similarly.  p-Anisaldehyde (28.5 g.), 18.0 g. cyclopentanone (III), 200 ml. Et2O, and 200 ml. N NaOH
stirred 64 hrs. at room temp., the aq. layer sepd. and extd. with Et2O, the combined Et2O exts. washed, dried, and concd., and the residue distd. in vacuo gave 30 g. p-anisalcyclopentanone (IV), b25 175 Deg, m. 68-9 Deg (iso-PrOH).  A higher yield of IV was obtained when the same reactants in Et2O and N NaOH were shaken 15 hrs. at room temp.  Furfural (32 g.), 28 g. III, 150 ml. Et2O, and 0.1N NaOH stirred 45 min. and the product distd. in vacuo gave 55 g. furfurylidenecyclopentanone, b15 154 Deg, m. 59-60 Deg (isopropyl ether).  BzH (212 g.), 218 g. cyclohexanone (V), and 1 l. N NaOH refluxed 3 hrs. gave 273 g. benzalcyclohexanone (Va), b10 173-83 Deg, m. 54 Deg (ligroine).  When substituted benzaldehydes were condensed with V, heating under reflux was applied 5-6 hrs.  With less reactive aldehydes (o- and p-chlorobenzaldehyde), two fold molar quantities of V gave improved yields.  The o-Cl deriv. b0.15
128 Deg and the p-Cl deriv. m. 82 Deg.  Furfural (196 g.) added in 2 portions to 200 g. cyclohexanone
and 2 l. N NaOH, after addn. of the first part the temp. reached 34 Deg in 2 hrs.; when the temp. dropped to 30 Deg the remaining half of the ketone was added and stirring continued 21 hrs., and the product isolated as above gave 217 g. II, b0.2 103 Deg, m. 46-7 Deg.  The I reagent was added rapidly with
stirring to a slight excess of cyclanone dissolved or suspd. in a five- or six-fold amt. of the appropriate solvent system.  The reaction was strongly exothermic and the temp. maintained at 30 Deg by cooling; after 20-30 min. the reaction slowed down, quenched by the addn. of Et2O and H2O, when 1.0 atom of active O had been consumed, and the product was isolated from the Et2O soln.  When the Et2O solns. obtained from reaction mixts. contg. massive amts. of KOAc were evapd. the residue usually crystd., furnishing crude lactones RC6H4CH:C.(CH2)n.CH2.C(O).O (VI); in a few cases partial purification by distn. in vacuo was necessary to bring about crystn.  Characterization of VI involved sapon. of the lactones in a slight excess of aq.-alc. alkali and treatment of the sapon. mixt. with semicarbazide reagent.
I (12 ml., contg. 0.076 mole peracid) was added during 10 min. to 14.05 g. Va in AcOH satd. with KOAc; after 40 min., about 93% of the I and 53% of the H2O2 content of the reagent had been consumed and after 70 min. about 95% and 68%, resp.  Extn. with Et2O and sepn. gave 8.4 g. VI (R = H, n = 2) (VIa).
Somewhat less pure material was isolated from the mother liquors to give a total yield of 67% based on I, 62% based on Va.  The following VI were thus prepd. (R, n, m.p. or b.p./mm., solvent of recrystn., m.p. of semicarbazone, recrystn. solvent, and neutralization equiv. are given): H (VIa), 2, 79-80 Deg, isopropyl ether, 162-3.5 Deg, aq. alc., 264; o-Cl, 2, 113.5-14.5 Deg, iso-PrOH, -, -, -; p-Cl, 2, 111-12 Deg, iso-PrOH, -, -, -; p-MeO (VIb), 2, 72-3 Deg, iso-PrOH, 157 Deg, aq. alc., -; 3,4-OCH2O, 2, 96-7 Deg, isopropyl ether-iso-PrOH, -, -, -; H, 3, 70-1 Deg, isopropyl ether, 158-9 Deg, aq. alc., 271; p-Cl, 3, 103-4 Deg, iso-PrOH, 163-3.5 Deg, aq. dioxane, -; p-MeO, 3, 67 Deg, isopropyl ether, -, -, -; H, (from 3-methyl-6-benzalcyclohexanone), 63.5 Deg, isopropyl ether, -, -, -; o-Cl, 3, 88-9 Deg, iso-PrOH, 188-9 Deg (decompn.), aq. dioxane, -; 2-furyl, 3, 137 Deg/1.5, -, 150 Deg, aq. MeOH, 269.  The
corresponding epoxides (VIIa) and (VIIb) were obtained similarly to VIa and VIb; VIIa m. 80 Deg (isopropyl ether) and VIIb m. 64 Deg (iso-PrOH).  They were isolated from mixts. obtained by using AcOH contg. small amts. of alkali acetate as the solvent.  7-Phenyl-6-hydroxy-6-heptenoic acid e-lactone (2.02
g.) was oxidized 16 hrs. at room temp. with 2% KMnO4, 5 g. K2CO3 added, the stirring continued 2 hrs., several small amts. of (CO2H)2 added to discharge the purple color of the soln., the mixt. filtered,
the filtrate concd., and the residue dissolved in H2O, acidified to pH 5, BzOH removed, and the filtrate worked up to give adipic acid.  VIa (1.3 g.) in 12 ml. AcOH treated 1 hr. with I gave 0.73 g. VIIa.  VIIa (0.10 g.) saponified at room temp. in 0.2N KOH in 3 ml. 50% alc. gave the acid, m. 62 Deg (CCl4-ligroine), neutralization equiv. 221.

The first of the two following articles describe a method for Baeyer-Villiger oxidation of unsaturated ketones with both hydrogen peroxide and a solution of sodium hydroxide added simultaneously to the unsaturated ketone in ethanol at -10°C. The formed enol acetate is hydrolyzed in situ, the products for 2-cyclopentylidenecyclopentanone being both 5-cyclopentyl-5-oxovaleric acid (25% yield) and it's ethyl ester (60% yield). Alkaline NaOH is a standard method for epoxidation of unsaturated ketones, so the fact that the reaction has been got to turn out as a Baeyer-Villiger oxidation is quite interesting. Guillanton even shows that the reaction really is a Baeyer-Villiger oxidation and does not proceed through the epoxide. The second article describes use of this reaction for preparing ketocarboxylic acids, although more sodium hydroxide is used. Too bad they don't tell the yields of the ester and the acid but go on and hydrolyse the crude reaction products by refluxing them in ethanolic KOH for ten hours. The hydrolysis and the use of fivefold amount of NaOH in the reaction might account for the lower yields, which range from 24% to the 45% for 2-benzylidenecyclopentanone. In my opinion the method of Guillanton should work for 3-benzylidene-2-butanone too with which there is no need to hydrolyze the formed ester ethyl acetate at all. Other oxidations are also described in these articles, K2SO8 among them, haven't compared it to the one posted already in this thread though.

Here is the method of Guillanton freely translated from French, I'd appreciate if someone better at French would proofread it and tell if there are errors.

To a solution of 0.5 mole of 2-cyclopentylidenecyclopentanone in 300 ml of ethanol or methanol cooled to -10°C is added a solution of 122 ml of 15% H2O2 and 18 ml of 4M NaOH simultaneously from two addition funnels regulating the addition so that the temperature does not rise (takes approximately 20 minutes). After returning to room temperature the mixture is neutralized with 10% H2SO4. Most of the ethanol is distilled off, the mixture is extracted with ether, the organic phase is dried with Na2SO4 and the solvent distilled off, leaving the crude product behind.

Action of epoxidizing agents on 2-alkylidenecyclopentanones.
Le Guillanton, Georges.
Bulletin de la Societe Chimique de France, (8), 2871-5 (1969).  Journal written in French.
CAN 71:112467  ISSN 0037-8968
Cyclic ketones I are treated with H2O2 to give d-oxoalkanoic acids RR1CHCO(CH2)3CO2H, where R and R1 and H and alkyl and aryl groups or (RR1C =) cyclopentylidene.  5-Cyclopentyl-5-oxovaleric acid is also
prepd. from the I compd. and K2S2O8 and HOOAc.

Synthesis of d-lactones.  IV.  6-Alkyl or 6-aralkyl d-lactones from cyclopentanone.
Ijima, Akie; Takahashi, Kiyoshi.
Chemical & Pharmaceutical Bulletin, 21(1), 215-19 (1973).  Journal written in French.
CAN 78:124397  ISSN 0009-2363
Reaction of cyclopentanone with aldehydes or ketones RCOR1 gave cyclopentanones (I; R = H, Me, Et; R1
= Me, Et, Pr, CHMe2, Bu CH2CHMe2, n-pentyl, n-hexyl, n-heptyl, n-octyl, Ph).  Hydrogenation of I gave
II, Baeyer-Villiger oxidn. of which gave III.


  • Guest
Maybe I expressed myself too cryptic up there...
« Reply #34 on: May 04, 2004, 03:40:00 PM »
The references you posted are good, but they aren't fully applicable for the case we are currently discussing, as alkyl cycloalkene ketones does not suffer from the side-reaction where the double bond gets epoxidized:

Post 503547

(Rhodium: "Baeyer-Villiger on unsaturated ketones", Novel Discourse)


  • Guest
Good to know. I tried to find out about that a
« Reply #35 on: May 04, 2004, 03:53:00 PM »
Good to know. I tried to find out about that a few months ago, but then forgot about it.


  • Guest
Seleninic acid catalyzed Baeyer-Villiger Oxidation
« Reply #36 on: May 14, 2004, 11:08:00 AM »
Here is the article I mentioned in

Post 503547

(Rhodium: "Baeyer-Villiger on unsaturated ketones", Novel Discourse)

Reaction of ?,?-unsaturated aldehydes with hydrogen peroxide catalysed by benzeneseleninic acids and their precursors
Ludwik Syper

Tetrahedron 43(12), 2853-2871 (1987)



Oxidation of ?,?-unsaturated aldehydes with hydrogen peroxide catalysed by benzeneseleninic acids and their precursors has been investigated. Bis 2-nitrophenyl diselenide has proved to be the most effective catalyst. The major products resulting from the oxidation are vinyl formates (a) which on hydrolysis give saturated aldehydes or ketones (g) having the carbon chain shortened by one carbon atom, compared with the starting aldehydes. The minor products are formyloxyoxiranes (b), ?-hydroxy-carbonyl (e) and ?-formyloxycarbonyl (f) compounds with the carbon chain shortened by one carbon atom. Carbonyl compounds (d), formally derived from an oxidative fission of the carbon-carbon double bond, have been also isolated. Diformyloxy (4c) and formyloxyacetoxy phenylmethane (5c) have been isolated when cinnamaldehyde (4) or 1-phenyl-2-formyloxypropane (5a) were oxidized, respectively. Possible mechanisms of formation of these products are discussed. Similar products resulted when ?,?-unsaturated aldehydes were oxidized with organic peroxyacids.

Offline carl

  • Global Moderator
  • Founding Wasp
  • *****
  • Posts: 5,626
  • circular pastry filled with hazelnut crime
Re: New method for P2P
« Reply #37 on: May 09, 2020, 11:04:44 PM »
Apparently, orthoboric acid can substitute the HCl in the condensation step between MEK and benzaldehyde.
Don't ask me for a reference though, it was told me from a first-hands experience.
I would suggest that you guys share information like it was the last day on Earth.  This information slowdown is all because of all that dumb unwillingness to share.  That is where the DEA is winning.  There goal is you not talking to each other.  Let the information flow.  I  promise we will always be 2 steps ahead of DEA chemists if we just keep sharing information
Real bees just hear the buzzing and it doesn´t ever stop. Ever.