Questions tagged [reaction-mechanism]

The detailed (and as complete as possible) description of plausible or observable pathways leading from reactants to products of a chemical process. This tag should be applied to questions about these processes. It may be applied to hypothetical and/or proposed mechanisms.

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Radical Chain Reaction, termination steps

In the termination step of radical chain reaction, we often neglect the recombination of hydrogen atom radicals and it will not be included in the mechanism. Let say the reaction is between $\ce{H2}$ ...
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Why do resorcinol and iodine react to give 2-iodobenzen-1,3-diol?

I am supposed to perform the above shown reaction in the lab soon, but I don't really understand the mechanism behind it. I got told by my lab assistant that the mechanism is an electrophilic aromatic ...
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Cyanide hydrolysis; could it yield an oxime?

The mechanisms for both acid and base catalyzed hydrolysis of nitriles are clear; (With the subsequent deprotonation from the hydroxyl) and (Source) In both cases, the hydroxyl adds to the carbon ...
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Yield of alkyl chloride in the Hunsdiecker reaction

Apparently the yield of alkyl chlorides is low as compared to that of alkyl bromides when preparing alkyl halides using the Hunsdiecker reaction. Why does this occur? The only factor I can see is the ...
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Why are we not getting the most stable product in Aldol condensation?

The picture above is from my class notes. I am familiar with the mechanism of both acid and base catalysed Aldol condensation. I also understand the reason why KCP was told as the major product in ...
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Proton removal during benzyne formation in substituted haloarenes

I encountered the following question in an organic chemistry paper - The reaction follows benzyne mechanism. My answer was B. However, the answer given in the test solutions was D. The mechanism ...
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Regarding Hard and Soft nucleophiles

In the above reaction, I was told that the reason organocadmium reacts only with aryl chloride segment is because it is very less reactive and reacts only with most reactive sites. This was consistent ...
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Why negative charge delocalises away from electronegative atoms

In the mechanism for the Wolff-Kishner reduction, after the $\ce{OH-}$ abstracts a proton, the resulting negative charge delocalises away from the nitrogen atom to the carbon, and the subsequent ...
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Is Chromium (VI) fluoride be synthesized properly?

Chromium (VI) fluoride, also known as chromium hexafluoride is a possible chemical compound with a chromium atom attached to 6 fluorine atoms. It has been unsuccessfully synthesized a number of times ...
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Products of the reaction between ethoxyethene and HI

Problem The products formed in the reaction $$\ce{CH2=CHOCH2CH3 + HI ->}$$ are (a) $\ce{CH2=CHI}$ and $\ce{CH3CH2I}$ (b) $\ce{CH2=CHI}$ and $\ce{CH3CH2OH}$ (c) $\ce{CH3CHO}$ and $\ce{CH3CH2I}$ (d) ...
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On the molybdenum(III) oxide-catalysed oxidation of alkanes to carbonyls

The following reaction is specified in my notes; $$\ce{CH4 ->[Mo2O3, \Delta]HCHO}$$ The intermediate steps involve the dehydration of an alcohol to yield the final product. Wouldn't this only work ...
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Mechanism of formaldehyde / phenol condensation

The production of bakelite using this method, but with an acid as the catalyst is simple enough; a protonation of the carbonyl oxygen, followed by an electrophilic substitution to the ring. The ...
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First step in a reaction between an acyl chloride and sodium acetate in acetic acid

What would the first step be in a reaction between acyl chloride and sodium acetate in the presence of acetic acid? I'm a bit confused because I'm not quite sure which step would occur first. I was ...
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On which side is the intermediate carbocation formed during acid-catalyzed opening of epoxide?

I found an organic chemistry question which asked the major product of the following reaction - The mechanism for the same in the answer was - My questions regarding this are as follows - The ...
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Periodic acid oxidation of carbonyls?

The following reaction seem to be valid; $\ce{CH2OH-CHOH-CH2OH ->[HIO4]CH2O + HCOOH + CH2O + 2H2O}$ Apparently, there are similar reactions by 2,3-dihydroxypropanal, and also by the straight chain ...
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Lindemann-HInshelwood mechanism difference between high and low concentration

I have a gas reaction which follows the Lindemann-Hinshelwood mechanism and want to calculate the rate constant at low and at high concentrations of the gas but I find myself stuck at what my next ...
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What is the reaction mechanism between boric acid and 2-ethyl-1-hexanol

Here is a photo from an article, Hydrometallurgy 2016, 160, 129–136 This indicates the reaction mechanism as esterification. However, the written reaction equation ($\ce{H3BO3 + nROH -> H3BO3.nROH}...
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Which oxygen is favored for protonation when hydrolysis of an acetal occurs?

My question is about which oxygen is favored for protonation in acidic conditions. So, R1 and R2 are different in the following diagram (for example, one is propyl but the other is ethyl). I looked up ...
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Why does (2-methoxyethyl)benzene undergo nitration at the ortho position (major product)?

This is an option in a question in which we needed to mark all the correct reactions: According to the answer key, this is a correct option. As an alkyl group is directly bounded to the benzene ring, ...
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On the use of hexane in the organic reduction by DIBAL-H

In some variations of the organic reduction by DIBAL-H, I've seen hexane used, as in this equation from this website; I've looked it up, but I haven't seen any explanation for why hexane's used there....
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What reagents are used to selectively reduce 2,2,3‐trimethyloxirane to secondary and tertiary alcohols?

Problem Answer Questions I know $\ce {LiAlH4}$ is a reducing agent because it gives four $\ce{H-}$ and will attack on our reactant on carbon with less substituents, i.e. in this case on $\ce{-CH-}$ ...
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On the relative ease of E2 dehydration

Concerning alcohol dehydration, I get that it's E1 in secondary and tertiary alcohols, that it's E2 in primary alcohols, and also why E1 reaction is easier for tertiary alcohols as compared to ...
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Lindemann–Hinshelwood mechanism for a gas reaction

The effective rate constant for a gaseous reaction which proceeds by a Lindemann–Hinshelwood mechanism is $\pu{1.01E-5 s^-1}$ at a concentration of $\pu{4.6E-6 M}$ and $\pu{2.21E-5 s^-1}$ at a ...
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Difference between Tishchenko reaction and Meerwein-Ponndorf-Verley reduction

For the Tishchenko reaction, Al(OEt)3 is used as reagent where an aldehyde is oxidized as well as reduced, so it's a redox reaction. Whereas in Meerwein-Ponndorf-Verley reduction, an aldehyde is ...
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What is the literature value of the activation energy of the reaction between iodate and bisulfite?

I explored the Arrhenius equation using the reaction between potassium iodate (containing the IO3- iodate ion) and sodium metabisulfite (bisulfite ion), however I can't find a literature value to draw ...
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Acid catalyst decarboxylation of 1-carboxyl-tryptoline

One of my labs had the following reaction: I understand the Pictet Spengler mechanism. However, I am confused about the decarboxylation. I cannot come up with a way in which this decarboxylation ...
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How is this Cope Reaction forming Ethene as major product?

I have been asked to find the major product of the reaction: As this a case of pyrolysis of $3^{\circ}$ Amine Oxide (or, in other words, Cope Reaction), I figured there are two possible products ...
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Determine reaction order and reaction rate

In a solution of $\ce{Fe^3+}$ the concentration was measured to be: $$\begin{array}{c|c} t/\pu{min} & \ce{[Fe^3+]}/\pu{\mu M} \\ \hline 10\ & 238\\ 20 & 227\\ 40\ & 206\\ 60\ & ...
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Stabilization of multiple bonds through inductive effects

In the conversion of m-chloroanisole to m-anisidine using $\ce{NaNH2}$ and liquid $\ce{NH3}$, apparently the reason the $\ce{NH2-}$ goes for the meta- position instead of the para position is that, in ...
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Where do I find data on 'molecular membership' sequences?

Techniques such as isotopic labeling allow for radioactive tracing of an element through a sequence of molecules. Using analytical instruments (such as LC-MS) we can then find out where labelled atoms ...
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How is the hydrazone formed in the Wolff-Kishner reduction?

In the Wolff-Kishner reduction the first step is to react a carbonyl with hydrazine to form a hydrazone. The later steps of the reaction requires a strong base to cause loss of nitrogen. However, the ...
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Mechanism of hydrolysis of acyl chlorides

The following mechanism for acyl chloride hydrolysis was given by my professor : However I do not understand why in the second step, oxygen has a partially negative charge, should it not gain a ...
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Reaction of Copper and concentrated sulphuric acid

We know that dilute $\ce{ H2SO4}$ doesn't react with copper because copper has higher reduction potential ($0.33$) as compared to hydrogen ($0.00$). However, it reacts with conc. $\ce{H2SO4}$ and ...
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Hydration in Chloral [duplicate]

Chloral consists of two OH bonds on the same carbon, which is usually unstable, and leads to the evolution of a water molecule, and converts into an aldehyde. However, this is not observed in chloral, ...
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Hydrogen peroxide on damp clothes left out in the sun [duplicate]

Somebody told me that sunlight is a good bleach for clothes because leaving damp clothes outside in the sunlight will turn some of the water into hydrogen peroxide. Is this true. If yes, then why can'...
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Using the steady state approximation in the decomposition of nitramide to determine rate law

$\ce{O2NNH2 (aq) ->[\mathit{k}_1] O2NNH- (aq) + H+ (aq)}$ $\ce{O2NNH- (aq) + H+ (aq) ->[\mathit{k}_{-1}] O2NNH2 (aq)}$ $\ce{O2NNH- (aq) ->[\mathit{k}_2] N2O(g) + OH- (aq)}$ $\ce{H+ (aq) + OH-...
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Reaction of but-2-ene with Cl2/CCl4

I have often studied the reaction of Br2/CCl4 with But-2-ene which results in formation of But I wondered what would be formed if Cl2/CCl4 reacts with But-2-ene. Does it lead to the formation of ...
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Does a geminal or vicinal diiodide form upon addition of excess HI to but-2-yne?

Reaction: $\ce{CH3-C#C-CH3 + HI (excess) -> ?}$ Product : I thought of different carbons by the reasoning from this post earlier I posted. But it is given that both iodine atoms exist on the same ...
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Is there a way to convert aniline to phenol without diazotizing it?

I am a high school student and while reading about reactions on amines, I was trying to figure out a way to convert aniline $(\ce{C6H5NH2})$ to phenol $(\ce{C6H5OH})$ without diazotizing it with ...
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How to avoid explosion when there is a leakage of LPG gas and coal gas/town gas?

How to avoid explosion when there is a leakage of LPG gas and coal gas/town gas? What are the conditions of that happening? The related underlying chemical reactions are hydrogen and butane combustion ...
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Reliance of migratory aptitude on steric hindrance and its effect on rate of reaction

I've learnt that the migratory aptitude of phenyl is greater than that for methyl, for example. But how do I find the order of the same for any given 2 groups, like $\ce{Cl-}$ and $\ce{PhCH2CH2CH3-}$, ...
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Can sodium borohydride reduce hemiacetals?

In the synthesis of Panacene by Canesi et al. [1], a step involves the installation of an $\ce{-OH}$ group on a double bond, using the oxymercuration-demercuration procedure. However, the product ...
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Mechanism for Ce(IV) Oxidation of Naphthalene

S. Cotton's Lanthanide and Actinide Chemistry reports that naphthalene can be oxidized to naphthalene-1,4-dione using cerric ammonium sulfate (CAS), $\ce{MeCN, H2SO4},$ and $\ce{H2O}$.1 No mechanism ...
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Second-step activation energy in SN1 reactions

In SN1 reactions, it's known that there are generally two steps, with the first being the R.D.S step involving carbocation formation and the next having a lower activation energy. Why does the second ...
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Can secondary alkyl halides be used in the Corey–House synthesis?

I've been told by my teacher that the Corey–House synthesis cannot proceed with secondary alkyl halides; they will prefer to undergo elimination over $\mathrm{S_N2}$ substitution. [used as the pseudo ...
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109 views

Why is the molozonide adduct thermally unstable?

In the mechanism of alkene-ozonolysis, the intermediate molozonide adduct, which is a cyclical but symmetric molecule (shouldn't symmetry about the C-C single bond bring stability?), decomposes ...
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Confusion regarding dehydration of 1° alcohols

My lecturer told me that 2° and 3° alcohols prefer to dehydrate through E-1 mechanism. On the other hand, 1° alcohols tend to prefer the E-2 mechanism, which does not involve the formation of a ...
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Michaelis–Menten kinetics applied to a solution with two enzymes

Two enzymes are added to a solution containing a tow concentration of a substrate that they can both use. Which statement is correct? A. Both enzymes will use equal amounts of the substrate. B. ...
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Why does Birch reduction of naphthalene with isoamyl alcohol form tetralin instead of 1,4-dihydrodialin (as formed with C2H5OH)?

I recently came across this question, which required me to know the difference between performing a Birch reduction on naphthalene using ethanol and using isopentanol. Why does using isopentanol lead ...
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Does β-hydride elimination in main group metals occur?

As a side reaction of Grignard reagents, the following reaction is introduced on the Internet. I think this is β-hydride elimination reaction, but magnesium is a main group metal, not a transition ...

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