# Tag Info

24

I am uncertain about the "Popoff's" rule you mention. There are two reactions that can oxidize ketones, and one seems to follow the behavior you are suggesting, but does not form a carboxylic acid. The other reaction does form carboxylic acids, but is more complex. The Baeyer-Villager oxidation is an oxidation of ketones to esters using a peracid in the ...

17

The migratory aptitude list for the Baeyer-Villager oxidation is as it is because that is how the molecules undergoing the reaction behave. When we are learning about new reactions from a textbook, we often read about the mechanism and theoretical explanations of chemo-, regio-, and stereoselectivity. It is easy to forget that the experimental observations ...

11

According to Tony Gebely at Tea Epicure (https://teaepicure.com/tea-leaves-oxidation/), it's not steam per se, but rather heating that slows oxidation, by denaturing two enzymes (polyphenol oxidase and peroxidase) that are responsible for it. Steaming is simply one way to do this: Much of the oxidation process revolves around polyphenols, particularly the ...

10

Of your three "thoughts", you are correct that an aldol reaction is not an option. Not only is the product "crowded", but the reaction is reversible. [BTW, an aldol condensation occurs when water is eliminated from the initial aldol product. In the case of a benzoin aldol product, elimination of water is impossible.] Your second premise is a good one. ...

10

The given answer is wrong in many ways: 4 did not satisfy both criteria C and E, because it is not a chiral compound to begin with. 10 did not satisfy the criteria D, because it does give a precipitate with iodine in presence of $\ce{NaOH}$. That gives only 5 in given answer to satisfy all criteria. Let's eliminate given compounds in systematic order: ...

9

Cyclic ethers usually do not get oxidized by periodic acid. However, epoxides would do only if they were acidified first or use acidified periodic acid in the reaction (Ref.1). In general, acidified periodic acid has been used as a qualitative test for the presence of epoxide moiety in organic compounds (Ref.1). The procedure is a modification of the ...

8

Sorry @ JavaScriptCoder, but I've to agree with aventurin. I'd say idoform test should have been done in a certified laboratory because of safety concern. However, I think fractional distillation might be helpful for this identification (or simply verification). OP can do this at home since he/she has done simple distillation at home. Ethanol/water binary ...

8

The conventional mechanism is as follows: The phenol displaces one acetate group on iodine – this makes the iodine itself act as what is essentially a fancy leaving group. Nucleophilic attack at either the ortho or para position allows the loss of iodobenzene and another molecule of acetic acid. What I can't explain right now is why it chooses to go para ...

8

The answer appears to be "it depends" (perhaps this should not surprise an experienced organic chemist). According to the abstract of the paper by Mendelovici and Glotter [1] in steroid chemistry: Treatment of 3β- and 3α-hydroxy-(acetoxy-)cholest-4-en-6-one and of 6β-and 6α-hydroxy-(acetoxy-)cholest-4-en-3-one with MCPBA gives two types of product, ...

7

I think that correct answer should be 5 and 6 only, because: 12 will produce terephthalic acid, instead of benzoic acid as it possess two benzylic-H (also given by 7). 4 and 10 doesn't satisfy statement C and D, as you've mentioned.

6

The interaction of the alkene with m-CPBA is primarily nucleophilic/electrophilic in nature, i.e. the π MO of the alkene attacks the O–O σ* orbital. Therefore, the more electron-rich alkene (i.e. more highly substituted alkene) preferentially reacts. With methyl groups there probably isn't too much steric hindrance. m-CPBA approaches above/below the alkene ...

6

You can justify the formation of Benzaldehyde from Toluene by oxidising with peroxide just by looking at the mechanism of the reaction and think of migratory aptitude of Phenyl group , hydride and methyl group. Firstly, if we delve into the mechanism of the oxidation of Cumene, we'll find that there is a rearrangement step in the mechanism. The ...

6

This source states that MCPBA gives preferential epoxidation of the more substituted alkene. This source explains that due to intra-molecular hydrogen bonding in solution, the high degree of polarisation results in an electrophilic oxygen atom that adds to alkenes. The most substituted alkene will be the most electron-rich alkene and hence the most ...

6

This quote is from Comprehensive Organic Name Reactions and Reagents by Zerong Wang. The oxidation of adjacent diols with periodic acid or its salt in aqueous solution is generally known as the Malaprade reaction. Several solvents have been used to increase the solubility of organic substrates and the reaction proceeds faster under acidic conditions. This ...

6

3 nitrogroups of TNT are rich of oxygen, but the aromatic ring has only carbon and hydrogen atoms. Therefore oxygen of nitrogroups oxidizes carbon and hydrogen atoms. There is no principle difference between oxidation and reduction agens being separate molecules, or being different parts of the same molecule. Note that TNT, in contrary to e.g ...

5

In J. Org. Chem. 1979, 44 (15), 2726–2730, the authors Lee and Chang have investigated the permanganate oxidation of alkynes to α-diketones. In addition, they investigated the oxidative cleavage of several α-diketones to carboxylic acids. In the case of hexadecane-8,9-dione, permanganate oxidation under at least three sets of conditions provided ...

5

The mechanism of haloform reaction will also be almost similar in the case if we use hypohalites (here, it is $\ce{NaOCl}$). In the first step, instead of $\ce{OH-}$, the acidic $\alpha$ proton will be taken up by $\ce{OCl-}$ (Remember, $\ce{HOCl}$ is a weak acid (but not as weak as water), so it's conjugate base i.e $\ce{OCl-}$ is a moderately strong base ...

5

Here are the three equations describing the reduction of manganese (and concurrent oxidation of whatever substrate may be present) under basic, neutral and acidic conditions respectively. $$\ce{Mn^{+7}O4- +e- ->~ Mn^{+6}O4^2-~~~~[basic]}$$ $$\ce{2H2O + Mn^{+7}O4- + 3e- ->~ Mn^{+4}O2 + 4OH-~~~~[neutral]}$$ \ce{8H+ + Mn^{+7}O4^{-} + 5e- ->~ Mn^{+2} ...

5

From the article by van Asselt and van Krevelen [1]: Cyclohexanol is oxidized to cyclohexanone. The cyclohexanone reacts with the nitrous acid to yield isonitrosocyclohexanone producing 2-nitro-2-nitrosocyclohexanone by reaction with nitric acid. With attendant ring opening and uptake of water the latter compound is transformed into 6-hydroxyimino-6-nitro ...

5

From the Institute of Minerals, Materials and Mining, Most aluminium foil is made from pure aluminium, but increasingly alloys are used to improve properties and reduce the thickness required. If you want to make sure that the Aluminium foil you're using is pure, the only way would probably to ask the manufacturer. Other than that, it could be the case ...

5

The selective Baeyer-Villiger Oxidation of unsaturated ketones is definitely depends on the conditions used. I do not want to eloborate this fact any further because it was well documented in Waylander's answer. Howevr, so far into the literature suggest that use of peracids in presence of unsaturation in the substrate ketone is not a good idea. The quote "...

5

The provided link (Lab Tutorial at Washington University in St. Louis) states the following: Another problem for water-treatment plants in the Great Lakes and Mississippi Valley is zebra mussels, which can "congregate" at the water intake and clog the screen, eventually sealing it off. Potassium permanganate, KMnO4, can be used to kill these ...

4

There's probably no reliable chemical test for the presence of methanol in alcohol mixtures that could be carried out at home without decent laboratory equipment. Qualitative tests such as esterification with boric acid and subsequent flame test or oxidation to formaldehyde and its detection are unreliable, especially in the presence of ethanol. I advise ...

4

From the Wikipedia entry on Tollens 1 Tollens' reagent is a chemical reagent used to determine the presence of an aldehyde, aromatic aldehyde and alpha-hydroxy ketone functional groups The substrate you have drawn is an alpha-hydroxy ketone.

4

A similar reaction with chromium oxide in alkaline solution has been documented. The acidic chromium oxide serves the same role as alkaline KMnO4 i.e a strong oxidizing agent. As pointed out by @Waylander in the comments permanganate oxidizes double bonds even in aromatic compounds. Reference: $\large{•}$ Chromium Oxidations in Organic Chemistry; By G. ...

4

In each case the permanganate oxidises the most electron rich ring. In the nitro-substituted case, that is the unsubstituted ring, probably first at the position alpha to the nitro group, forming a phenol, then para to that to a quinone but permanganate keeps on chewing until the phthalic acid is formed. In the aniline case the most electron rich ring is ...

4

[Answer based on comments from @KemonoChen, @IvanNeretin and @NilayGhosh. Thanks for your input :D] In the presence of alkali (or acid, for that matter) aldehyde will turn against itself, creating all matters of ugly polycondensate products. See Aldol condensation and note that it ends up in another aldehyde, so the process can and will be ...

4

Acetone and sodamide give acetone sodium enolate A, nothing further happens until acetylene is introduced. The pKas of acetone and acetylene are both around 25 so an exchange occurs reforming acetone and creating sodium acetylide. This seems an unusual way of making sodium acetylide, but I don't think this is a real world example (unless someone can find a ...

4

As has been stated by @Beerhunter those benzylic hydrogens are a serious concern . Nonetheless, here is a different offering. To solubilize carboxylic acid 1 both the phenolic group and the acid should be protected. Here, both of the groups are protected as methyl groups. [An ester group and silylated (TBS?) phenol would also suffice.] The double bond of 2 ...

4

There are indeed examples of $\mathrm{PCC}$ oxidation of allylic alcohols to $\alpha, \beta$-unsaturated aldehydes. The first example is from the original Corey-Suggs paper while the other two cases are from the work of Dauben and Michno. References: E. J. Corey, J. William Suggs, “Pyridinium chlorochromate. An efficient reagent for oxidation of primary ...

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