# Tag Info

35

Some general information on side-chain oxidation in alkylbenzenes is available at Chemguide: An alkylbenzene is simply a benzene ring with an alkyl group attached to it. Methylbenzene is the simplest alkylbenzene. Alkyl groups are usually fairly resistant to oxidation. However, when they are attached to a benzene ring, they are easily oxidised by ...

22

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 ...

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 ...

7

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. ...

7

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 ...

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

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

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 ...

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 ...

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

[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 ...

3

The Baeyer-Villiger oxidation is conducted under acidic conditions such as an alkyl peroxide in the presence of a mineral acid (e.g.; H2SO4) or a peracid (e.g.; peracetic acid or m-chloroperbenzoic acid). In the reactions described in the diagram, the reactions of aldehyde 1 or α-diketone 7 are initiated by proton of the carbonyl oxygen followed by ...

3

Fun fact: this synthesis is/was the commercial method used by BASF to make the product, menadione, which is often found as a supplement in animal feeds (patent DE092952709). Apparently the use of stoichiometric chromium is worth it. Why are alpha positions more reactive? There are two potential questions here, I'll try to answer both. 1) Why does ...

3

In the Wikipedia article of PCC, it is written that: PCC offers the advantage of the selective oxidation of alcohols to aldehydes or ketones, whereas many other reagents are less selective. Further, on the Wikipedia article of Collin's reagent, it is written that: This complex is both difficult and dangerous to prepare, as it is very hygroscopic and ...

3

There are many $\ce{CrO3}$ oxidation reagents (Jones, Sarett, Collins, PCC, etc.), however, most are selective and stop the oxidation of a primary alcohol at the aldehyde stage. On the other hand, the Jones reagent is relatively unselective and will oxidize a primary alcohol to the corresponding carboxylic acid - if enough reagent is present. It takes two-...

3

If I was tasked with making 4-oxooctanoic acid I would not start from octanoic acid! There is no easy way of making 4-oxooctanoic acid directly from octanoic acid. It is however a relatively trivial exercise from other starting materials. My suggestion is to react the commercially available ethyl succinyl chloride (ethyl 4-chloro-4-oxobutyrate) with n-...

3

Reactive oxygen species, primarily superoxide, may result from one-electron reduction of molecular oxygen. Given that aerobic metabolism involves loooooong chain of electron transfers, it isn't all that rare. Human body uses specialized enzymes to defang reactive oxygen species. The most well known are peroxidase and superoxide dismutase (see wiki for ...

3

Some enzyme-catalyzed reactions produce free radicals as short-lived intermediates, but these are likely to be contained within the enzyme active site until they can react further to form product. Example: ribonucleotide reductase - which catalyzes the formation of deoxyribonucleotides and enables the production of DNA. I can't think of any case where a ...

3

Sodium dithionite Na2S2O4 (also called sodium hydrosulfite) is a flexible reducing agent that reduces and cleaves ArN=NAr bonds to give ArNH2. It is also good for ArNO2 to ArNH2 and reductions of enones to ketones. Further reading here 1

3

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 ...

3

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 ...

2

The best approach, and good practice, is to draw out the reaction products for each case. You should know that alkaline potassium permanganate replaces a carbon-carbon double bond with two carbon-oxygen bonds, one to each of the original double-bonded carbons. For instance, with 2-butene we have: $\ce{CH3-CH=CH-CH3 -> CH3-CH=O + CH3-CH=O}$ Here the ...

2

I think the final oxidation product should be carbon dioxide ($\ce{CO_2)}$ if acidified potassium permanganate is present in excess amount. Firstly, ethylene glycol will be oxidised to oxalic acid. But oxalic acid can still be oxidised. In fact, it is the concept of titration of oxalates with potassium permanganate ($\ce{KMnO_4}$). Under acidic conditions, ...

2

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 ...

2

@Waylander: A general Procedure given in J. Org. Chem. 1999, 64(7), 2564–2566 as follows: Typical Procedure. A mixture of alcohol 1 ($\pu{40 mmol}$), TEMPO ($\pu{436 mg}$, $\pu{2.8 mmol}$), $\ce{MeCN}$ ($\pu{200 mL}$), and sodium phosphate buffer ($\pu{150 mL}$, $\pu{0.67 M}$, $\pu{pH = 6.7}$) is heated to $\pu{35 °C}$. Then mixtures of $\pu{9.14 g}$ of ...

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