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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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How to calculate the kinetic order of an enzymatic reaction?

This question is concerning the metabolism of ethanol by an alcohol dehydrogenase enzyme. Usually people metabolize alcohol equivalent to "one beer per hour". One beer is said to contain 33cL. The ...
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1answer
75 views

Can anyone tell me what reaction is this?

I came across this reaction, but I have no idea what reaction is this. Can anyone please tell me? What will be the products? My first guess is that a carbene will be formed which will attack on the ...
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Mechanisms of Birch and Bouveault-Blanc Reductions

The question is all about the sequence of a possible Birch- and Bouvault-Blanc-Reduction in this exemplary substrate. With which reduction the mechanism begin? My first attempt was to classify the ...
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Does OH- attack carbonyl carbon in aldehyde during aldol reaction?

Why does $\ce {OH^-}$ not attack the carbonyl carbon in an aldehyde during the aldol reaction and instead, deprotonate the $\alpha$ hydrogen to form an enolate intermediate? Also, why does the ...
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Diels Alder stereoselectivity

I'm familiar with the endo rule as well as the regioselectivity of the reaction. However, what I fail to understand is the stereoselectivity of the product in relation to the diene. For example, in ...
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2answers
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Why isn't iron (III) oxide an effective catalyst for decomposing hydrogen peroxide?

I've been working on a project involving the catalyst iron(III) oxide for decomposing hydrogen peroxide. It barely seemed to produce any oxygen. https://www.youtube.com/watch?v=Ta4DomSDzF8 This video ...
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What is a probable mechanism for acid catalysed decarboxylation of alpha-hydroxy acid?

The following question was on one of the tests we had recently Now i worked out the intermediates and the product as follows: The first step is an intramolecular Cannizzaro reaction in which the ...
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Where will a H+ attack on 6-hydroxyhexan-2-one? [closed]

Where will a H+ attack on 6-hydroxyhexan-2-one? Protonation can take place either on the ketone or the alcohol. So where will it attack? In short, on which of the two oxygen atoms is electron density ...
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1answer
51 views

Friedel–Crafts with unsaturated halides

Which of the following compounds will not undergo Friedel–Crafts reaction with benzene: vinyl chloride or allyl chloride? According to me vinyl chloride will be a better electrophile than allyl ...
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Abnormal reaction of grignard reagent

My book states that: When isopropyl magnesium bromide is added to diisopropyl ketone, the expected tertiary alcohol is not obtained; instead the secondary alcohol; diisopropyl carbinol is obtained ...
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1answer
49 views

Can't decide between E1 and E2 mechanisms for this reaction

I can see that due to the substrate being bulky, an elimination reaction will take place and not substitution. The reagent is a strong base. E1 reactions are independent of the base chosen, and E2 ...
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Organic Chemistry - Reduction

Can anybody help me with the product? Seems like Birch reduction, but Birch reduction is used for conjugated systems and alkynes.
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Clarification in the mechanism for Molisch's test for glucose

Wikipedia says Molisch's test is a sensitive chemical test, named after Austrian botanist Hans Molisch, for the presence of carbohydrates, based on the dehydration of the carbohydrate by sulfuric ...
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Are nucleophilic aromatic substitutions stepwise or concerted?

Recently, there has been a lot of discussion about nucleophilic aromatic substitution (SNAr) reactions apparently being concerted instead of stepwise (e.g. Krämer, K. Textbook aromatic substitution ...
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Ozonolysis mechanism question

Is this mechanism will be similar to ozonolysis ? My try : My Question is will B be the answer ? And what does Me2S do ?
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1answer
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What is/are the product(s) of the reaction of (5,5-²H₂)cyclopenta-1,3 diene with NaH, and quenched with H₂O?

$\ce{NaH}$ breaks as $\ce{Na+}$ and $\ce{H-}$. Here $\ce{H-}$ acts as a nucleophile and attacks at a place where the electron density is less. But the $\ce{C-D}$ bond is stronger than the $\ce{C-H}$ ...
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1answer
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Why are reactions with higher activation energy more sensitive to temperature?

In the above picture it is stated clearly, with an example, that the more the Ea of a rxn the more it's sensitive to temperature, and hence even a small change in temperature in a reaction with high ...
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1answer
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Which reaction rate formula is suited for diatomic molecules in a plasma?

I am an experimental physicist, so I unfortunately do not know much about chemistry except the basics. For my current study, I am investigating diatomic molecule formation in plasma. These diatomic ...
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1answer
167 views

hydrogenation using H2 + Ni2B [closed]

I am having trouble understanding why hydrogenation with $\ce{Ni2B}$ gives anti-addition. all my book says is this: Could someone explain the mechanism.
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1answer
86 views

Most reactive site for electrophilic aromatic substitution

I was given a problem in which I had to identify the most reactive site for electrophilic substitution out of the positions 1,2,3,4 (shown in the figure). My Approach: Upon drawing the resonating ...
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0answers
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What is the purpose of tetrazole in oligonucleotide synthesis?

The ATDBio book on nucleic acids describes tetrazole as an activator required to couple nucleotides. The diisopropylamino group of the nucleoside phosphoramidite is protonated by the activator, ...
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Reaction between Salicylaldehyde and 2-Benzoylpyridine

In a paper by Sheng et al (10.1016/j.dyepig.2018.07.036) the authors synthesize the compound MZC as shown in the scheme below. I'm looking for information about what the reaction mechanism is that ...
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1answer
210 views

Reaction between HCl and NaHCO3 [duplicate]

I want to know why in the reaction between HCl and NaHCO3, we have CO2 and H2O instead of H2CO3 ?
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1answer
124 views

Why do nonmetal oxides react with water to form acidic compounds? [closed]

I am confused about the molecular basis by which nonmetal oxides react with water to form acidic compounds. For example, I understand that sulfur trioxide reacts with water to form sulfuric acid as ...
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1answer
71 views

Regioselectivity in Diels Alder reaction

Since $\ce{-CN}$ shows strong $\ce{-I}$ effect, there will be $\delta +ve$ charge on the carbon adjacent to it. Similarly, $\ce{-NO2}$ shows strong $\ce{-I}$ and $\ce{-M}$ effects. So I this is my ...
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1answer
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Alcohol protection with ethers

Various ethers are used for hydroxyl protection. My question is about their removal. I know that there are various methods but I want to specify on the use of acids. Certain groups are removed easily ...
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2answers
41 views

Acetal Formation Mechanism

In this example, why is there is a ring formation with the attack of the OH from the intermediate itself rather than a continuation of addition? I know my proposed product is wrong, however I just ...
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25 views

Please explain the reason why E2 mechanism occurs

I known as that when the weak bases are reacting with 2° alcohol, E1 mechanism occurs. But, in the picture, E2 mechanism is occurred. Why E2 mechanism occurred? In step [3] Weak base : pyridine Did ...
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1answer
135 views

Optimum pH range for formation of Schiff bases

What is the optimum range of pH for the formation of Schiff Bases by the addition of hydroxylamine to an aldehyde or a ketone? According to Peter Sykes' A Guidebook to Mechanisms in Organic Chemistry,...
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2answers
58 views

Aldol condensation in acidic medium

Attempt: I did aldol condensation in acidic medium followed by $\ce{E1cB}$ to get 1,3-diphenylbut-2-enone but the answer given is: I am unable to devise a mechanism to reach the above product from ...
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How did Zyklon hold and release HCN?

$\ce{HCN}$ is notoriously unstable: It boils at room temperature, and it tends to polymerize when concentrated in unbuffered liquid form. Yet $\ce{HCN}$ was for decades widely used as a fumigant ...
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109 views

Mechanism of oxidation of phenol to quinone by chromium(VI)

In the supplementary information for Org. Lett. 2005, 7 (19), 4297–4300, the following experimental method for the synthesis of 2-bromo-6-methylcyclohexa-2,5-diene-1,4-dione is given: To a ...
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1answer
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Why cyclohexane-1,4-dicarbaldehyde does not give aldol condensation?

I was recently came to know as a fact that cyclohexane-1,4-dicarbaldehyde does not give the aldol condensation reaction in spite of possessing α-hydrogens. I was told that this is due to steric ...
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Soda mixed with lemon juice [closed]

I mixed 1 tbsp of soda and 1 squeeze of lemon juice in a glass. There was strong reaction with a lot of foam. What caused such a reaction?
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1answer
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Stability order of methy benzyl cations?

I know that meta position shown no resonance effect and hyperconjugation effect . So According to the order given I guess Hyperconjugating effect is taken into account as -CH3 has no Resonance effects....
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1answer
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Oxymercuration demercuration, PCC, NaCN/HCl reaction

In this reaction of the alkene, the correct answer is below but I don't understand why it goes to that. This is my thought process - reagents 1 and 2 do oxymercuration demercuration and makes a ...
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100 views

Major product of isomerization reaction

I am trying to come up with a logical mechanism for the following transformation, where 2-methylenecyclobutan-1-ol is converted to cyclopentanone under acidic conditions: What I have tried to do was ...
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1answer
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Can we interpret the “extent of reaction” as the number of reactions that happened?

Consider this reaction: $$\ce{\alpha\ A + \beta\ B -> \omega\ C + \delta\ D}$$ Where $\ce A$ and $\ce B$ are the reactants, $\ce C$ and $\ce D$ are the products, and $ \alpha, \beta, \omega, \...
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How to identify whether an electrophile will attack benzene ring when a deactivating group is attached to it?

I was asked to find out the major product formed when this molecule is subjected to nitration using $\ce{HNO3/H2SO4}$ mixture Here $\ce{NO2+}$ will be the electrophile. Lets call the benzene ring ...
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Reaction of phoshorus pentasulfide with ethers

Why does phosphorous pentasulfide on reaction with ethers give dialkyl sulfides? I searched for this reaction in my organic chemistry reference books and the internet but couldn't find it. What is ...
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1answer
496 views

What is “mechanistic duality”?

I am doing a general overview of different kinds of dualities present in science. I am quite well versed with the dualities in physics and mathematics. I was searching for dualities in chemistry, ...
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155 views

Electrophilic addition of IBr to alkene

I would assume options A and B are possible products due to the $\ce{I+}$ electrophile attacking the alkene, and hence are ruled out. However, I am torn between options C and D. Both products are ...
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Show that this mechanism is consistent with the rate law - how to?

The problem is from Principles of general chemistry, 2nd edition by Silverberg, chapter 16 problem no.81: "Even when a mechanism is consistent with the rate law, later work may show it to be ...
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195 views

Why can't terminal alkynes take part in Birch reduction?

According to my book terminal alkynes are not observed in Birch reduction.Why is this so? The only property I know about them is that they are slightly acidic. Does this have something to do with it? ...
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Why can't a quaternary carbon product be obtained by alkane isomerization in presence of AlCl3 and HCl?

This question actually deals with the reaction in another question: Isomerisation of alkanes under Lewis acidic conditions. I have a further doubt, regarding this reaction my book says that a ...
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1answer
38 views

Formation of (Gamma) Methylparaconic acid

I came across this question recently, I tried to devise a mechanism but I'm struck here, My try - Moreover, I think my mechanism is somewhat inefficient because of formation of some byproducts, ...
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293 views

What is the mechanism of alkane combustion?

I understand that combustion of hydrocarbons (such as alkanes) produces energy by breaking bonds: $$\ce{C_nH_{2n} + $\frac{3n}{2}$ O2 -> nCO2 + n H2O}$$ And I can find dozens of explanations of ...
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How does Boudouard reaction influence the temperature?

I've a question that is giving me a lot of troubles: I'm depositing and gasifying Carbon by varying a flow rate of $\ce{CO}$ and $\ce{CO2}$ and by using the Boudouard reaction ($\ce{2CO -> C + CO}$)...
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Do Sodium Alkynides react with esters in the same way that Grignard reagents do?

We know that Sodium alkynides react with aldehydes and ketones like Grignard reagents. But do they behave the same way with esters?
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Organic chemistry. how to control the Friedel–Crafts alkylation rection to methylbenzene as the major product?

My question is due to a discrepancy I founnd in reactivity and organic conversions. In reactivity of organic compounds it has been established that an alkyl group activates the benzene ring and hence ...