The detailed and 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, which seek information on elementary steps of these processes. It may be applied to hypothetical and/or proposed ...

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3
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Ene-yne metathesis product

In the ene-yne metathesis how to know which product will form predominately, as the mechanisms to both are plausible?
3
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0answers
24 views

Grubbs' reaction and Woodward-Hoffmann rules

The mechanism of the olefine metathesis using Grubbs' catalyst consists of many [2+2] cycloadditions and reverse cycloadditions. How are they in accordance with the Woodward-Hoffmann rules? I think ...
2
votes
1answer
56 views

Gattermann-Koch Reaction with Phenol Substrates

The Gattermann-Koch Reation involves the formation of an aryl aldehyde using carbon monoxide and hydrochloric acid as reactants. The reaction is catalyzed by Aluminum Tri-Chloride in the presence of ...
10
votes
2answers
65 views

Exocyclic vs. endocyclic double bonds in E1 elimination

What will be the major product of this elimination reaction? The exocyclic product has more substituent groups on the alkene which should make it more stable but I have heard that exocyclic alkenes ...
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0answers
27 views

What is the outcome of 2-chloro-2-methylpropane reacting with NaOH? [on hold]

I need a detailed explanation of the reaction mechanics and what could be other outcomes.
6
votes
1answer
87 views

Acid catalysed hydration of allene

In the acid catalysed hydration of allene, acetone is obtained as the major product. This is because of electrophilic addition of $\ce{H+}$ across a double bond to give a vinyl carbocation, and ...
7
votes
1answer
102 views

Thermodynamic vs Kinetic Sulphonation of Naphthalene

The left hand isomer is clearly the kinetically favoured product and the right hand isomer is the thermodynamically favoured product. However, I have no idea why. Can you explain?
4
votes
1answer
37 views

Ketone to alkene regiochemistry

What are the reagents for the following reactions: Typically, when thinking about ketone to alkene reactions, one thinks of the Wittig reaction. However, I don't see an appropriate form of that ...
5
votes
0answers
55 views

What will be the final product of this reaction?

ATTEMPT: The first step will be the attack of $\ce{PhMgX}$ on carbonyl carbon, that is, 1,2 position followed by hydrolysis, yielding an alcohol. But how does the reaction proceed with ...
3
votes
2answers
43 views

Heating of Ethers with HI and Cleavage of Ethers

Here is a question from my textbook:- Q - Give the major product formed by the heating of the following ether with HI. ...
11
votes
2answers
104 views

Does a Grignard reagent react with cyclohex-2-en-1-one to give the 1,2- or 1,4- product?

My attempt: The $\ce{PhMgBr}$ nucleophile attacks on the 1,2 position. But why, in this case, will it attack the 1,4 position?
7
votes
2answers
47 views

Migratory preference in a rearrangement involving carbocations

I just read about the Pinacol rearrangement and the following reaction was presented just after it. The book (Clayden) shows path 1 being taken. My question is why is the second path not taken? I ...
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votes
0answers
29 views

One liter solar for how many kilometer? [closed]

I have one question about LNG Carrier vessel moss. Do you know 1 liter solar, for how many KM? Thanks.
1
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1answer
30 views

Predicting the Product of a Substitution/Elimination Reaction

I am asked to explain why neither $\ce{E2}$ or $\ce{S_{N}}2$ products are formed when 3-chloro-2,2,4,4-tetramethylpentane is treated with NaOH. I realize that since the reagent is a strong ...
1
vote
0answers
40 views

What is the mechanism of formation of Grignard's Reagent?

What is the mechanism of formation of Grignard reagents? I couldn't find much in my book or on the Internet. This page says something which I am unable to understand. Why are the $2$ electrons in the ...
5
votes
1answer
128 views

Periodically oscillating chemical reactions?

I've seen before chemistry demonstrations where solutions are mixed with one another and subsequently where the resulting product goes through periodic color changes: for example blue to orange and ...
4
votes
1answer
46 views

Transformation of acyl group to carboxyl group in biphenyl system with two acyl groups at para position

How do I perform this reaction? I have prepared 4,4'-acylbiphenyl and want to make one acyl group into $\ce{-OH}$ and other into $\ce{-COOH}$ group.
4
votes
2answers
38 views

2,4-dinitrophenyl hydrazine test

I found this reaction over here: which illustrates the carbonyl test but looks fuzzy. Assuming that the R in the product is a typo for H, I couldn't conserve the number of Nitrogen atoms. ...
8
votes
0answers
38 views

Alkylation conjugated nitrile

Why does the enolate of the nitrile attack the alkyl chloride from the bond shown in the picture and not from the far end pi bond?
2
votes
1answer
40 views

What is the product of a Dieckmann condensation of dimethyl adipate

**ATTEMPT:-**MeO- preferably gives SN2 OR E2, being a strong base and good nucleophile. But which reaction proceeds in this case?
3
votes
1answer
37 views

Mechanisms in kinetic reactions

In my book is given the mechanism of $\ce{HBr}$ forming and I understand every step of it. We did the calculations of the rate of each reaction, which is easy depending on the sign (-,+) of compounds ...
4
votes
1answer
64 views

Ketene cycloaddition reactivity

Why do ketenes participate in [2+2] cycloadditions with their $\ce{C=C}$ bond and not the $\ce{C=O}$ bond? Can the reactivity be reversed somehow?
3
votes
1answer
79 views

What is the mechanism of the uncatalysed epoxide opening with alcohols?

The Wikipedia page says this: Ethoxylation is an industrial process in which ethylene oxide is added to alcohols and phenols to turn it into a surfactant. How does the reaction proceed? ...
8
votes
1answer
73 views

Formation of radicals from C-H and C-C bonds

Why do radical mechanisms favor the homolytic dissociation of a $\ce{C-H}$ bond over a $\ce{C-C}$ bond? The $\ce{C-H}$ bond is stronger in magnitude (and it's also slightly polarized), so why would ...
-1
votes
1answer
46 views

Applying Hess's Law Experiment

I was planning to do conduct an experiment using magnesium and hydrochloric acid and measure the temperature. For this lab, I need a manipulated variable, so I was wondering that would changing the ...
5
votes
1answer
55 views

Ring expansion from a given cyclic carbocation

How will the cyclobutane ring behave in the following case? I initially thought there would be ring expansion to a five membered ring so that there may be less angle strain and a secondary ...
7
votes
1answer
59 views

Purpose of ammine in Tollens' reagent

In this previous question the mechanism for the reaction of Tollens' reagent was outlined. As I understand it the oxidising agent in Tollens' is the diamminesilver(I) complex $\ce{[Ag(NH3)2]+}$ but ...
2
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0answers
46 views

How is it possible, that the hydrolysis of ethers proceed via a SN2 mechanism?

Ethers on hydrolysis with dilute $\ce{H2SO4}$ under pressure produce alcohols. This is basically a type of acidic cleavage of ethers by the $\mathrm{S_N2}$ mechanism. There is inversion of ...
7
votes
1answer
87 views

What is the role of pH in azo coupling reaction of diazonium with phenol and aniline?

Why is it so that azo coupling with phenol needs basic pH (9–10) and with aniline it needs acidic pH (4–5). How does pH participate in the mechanism? I have searched the internet for quite a while ...
4
votes
0answers
57 views

Solve this chemical or biological mystery

I hope this is the best place to pose this unique question. Please forgive me if it's not. I went into a closet to get a prescription medication that was filled about a year ago. The label on the ...
7
votes
1answer
71 views

Why would sulfuric acid turn gray/black?

About 2 years ago I purchased 2 liters of 98% concentrated sulfuric acid. It's in a standard poly bottle with leakproof lids, and originally was clear. Recently I noticed the acids have turned a dark ...
6
votes
2answers
130 views

Aromatic ether to phenol reagents

I have been asked to identify suitable reagents for the following transformation: (Apologies it's back to front - the question is a map of reactions and I took a snapshot). I really have no idea ...
7
votes
1answer
86 views

Mechanism for acid-catalyzed dehydration of 2,3-dimethylcyclopentanol

How do you get from 2,3-dimethylcyclopentanol to 1,2-dimethylcyclopent-1-ene? I know the -OH group leaves as water (being protonated by acid) forming a carbocation. Then the weak nucleophile (water) ...
1
vote
0answers
34 views

a chemical model for pde

Consider the initial boundary value problem $$u_t=a(t)u_{xx},\,\,\,0<x<1,\,\,\,t>0$$ $$-ku_x(0,t)=hu(0,t),\,\,\,t>0$$ $$u(1,t)=u_0,\,\,\,t>0$$ $$u(x,0)=f(x),\,\,\,t>0$$ where ...
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0answers
14 views

What radius best represents reaction distance?

Molecules must be within a certain distance for a reaction to begin as well as satisfying a myriad of other factors. Whilst the exact distance varies from reaction to reaction, is their any ...
5
votes
1answer
93 views

Mechanism for formation of amide by reaction of amine with ester

This is the mechanism given in my lecture handout: I have a problem with the third species along. Surely the negatively charged oxygen would protonate before the other oxygen would. Also, why does ...
4
votes
1answer
54 views

Amide synthesis SM alkylchloride

Suggest a synthetic route to amide C from the alkyl chloride B (reaction mechanisms are not required). Standard reagents and solvents may also be used. In this question immediate reaction is to ...
3
votes
1answer
98 views

Alkylation of alkenes by nucleophilic substitution

A double bond/alkene reacts as a nucleophile. I have never seen a reaction where it takes part in an $S_N1$ or $S_N2$ reaction with a halogenoalkane for example. This would presumably be a very useful ...
8
votes
1answer
53 views

Naproxene syntheses: electrophilic aromatic substitution on activated naphthalene

I am studying Syntex's naproxene syntheses and I came across a couple of electrophilic substitutions whose mechanism I can't understand. The first one is a Friedel-Crafts acylation: the products are ...
2
votes
1answer
75 views

Can carboxylic acids be used in the aldol reaction?

A question in a practice paper I did recently showed the aldol condensation of benzaldehyde with ethanoic acid. I think I am right in saying that carboxylic acids do not form enolates because the ...
3
votes
1answer
40 views

Oxymercuration Demercuration Mechanism doubt

I'm having a doubt on the mechanism of oxymercuration Demercuration reaction. How does the reaction, initially heading towards anti addition(after cyclic transition state formation) ,get spoiled by ...
3
votes
1answer
37 views

Mechanism of enolether formation with ethyl orthoformate in estr-4-ene-3,17-dione (Djerassi's norethisterone synthesis)

The second step of Djerassi's synthesis of 19-nor-17α-ethynyltestosterone (norethindrone), involves the protection of the ketone in position 3 via enolether formation, as in the picture: What is ...
4
votes
1answer
67 views

Effect of different electron withdrawing/transition state stabilising groups in nucleophillic aromatic substitution

I have been asked the following question in my problem sheet: The only differemce between reaction A and reaction B is the electron withdrawing group that stabilises the anionic transition state ...
3
votes
0answers
68 views

Calculate the number of moles of NO₂ (g) produced per hour per liter of air?

A reaction of importance in the formation of smog is that between ozone and nitrogen monoxide described by $\ce{O3(g) + NO(g)->O2(g) + NO2(g)}$ the rate law for this reaction is: rate of ...
6
votes
2answers
82 views

Claisen Condensation to Ketone

Can someone explain (and preferably draw) the intermediates of this reaction? I understand that it is a Claisen Reaction, and likely a condensation due to the heat, but I am not sure why there ...
2
votes
1answer
26 views

In regards to the addition of hydrogen to alkynes, does the amount of moles of Hydrogen matter?

Is there any difference between having the addition of 1 mole of hydrogen to 2-pentyne with a platinum catalyst compared to the addition of 2 moles of hydrogen(H2). I was under the impression that ...
1
vote
1answer
25 views

Reaction of ethylacetoacetate with Iodine

A "reaction map" in my lecture handout suggests that the product of this reaction is: So, basically overall it just merges two ethylacetoacetate molecules together at the central carbon. What is the ...
2
votes
1answer
48 views

Decarboxylation product of bicyclic compound

What is the decarboxylation product of the following species: It may seem straightforward but the product enolate involves a double bond with one end at the bridgehead carbon which is ...
1
vote
1answer
46 views

Mechanism for the formation of butanoic acid from ethylacetoacetate

My problem sheet asks me: "Draw a mechanism for the formation of $\ce{EtCH2COOH}$ from the reaction of $\ce{MeCOCH(Et)COOEt}$ with $\ce{NaOH}$ in $\ce{EtOH}$" This has got me stumped. The mechanisms ...
5
votes
1answer
48 views

What determines whether an aldol reaction will occur again or eliminate?

The product of an aldol reaction is a $\beta$-hydroxy ketone. This can go on to eliminate to form an alkene thus: However, the species on the far left of the above diagram (the $\beta$-hydroxy ...