The step by step sequence of elementary reactions by which overall chemical change occurs.

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Acidic conditions, high heat, and return to carboxylic acids

Apparently carboxylic acid derivatives such as cyanohydrins can be taken back to "daddy" - a carboxylic acid - under the right conditions. This involves acid, water, and "high heat." What, however, is ...
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19 views

Relationship between Auto-Ignition Temperature with Pressure and Fuel

Experimentally it appears that increase in pressure, fuel concentration, and chain length causes AIT to decrease until a minimum where even further increase in these parameters increases the AIT. ...
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25 views

Anti hydrogenation of alkynes-Purpose of NH4Cl

In my orgo textbook, Lithium is used to create a free radical of the alkynes, to then allow the anti addition of hydrogen to get an alkene. "The Dissolving Metal Reduction of Alkynes" is a reaction ...
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416 views

Are carbocations that bad?

My professor has an anti-fetish for carbocations. In any mechanism that we draw with a carbocation, the maximum earnable credit is automatically halved. In any case, he draws all mechanisms involving ...
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1answer
46 views

Are all esterification reactions reversible? What is their general mechanism?

For example the reaction of ethanoic acid with ethanol is reversible, however is this true for all esters? I'm not quite whether it is as easy for a reversible reaction to occur both ways. Is there a ...
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45 views

Relationship between Equivalence Ratio and Adiabatic Flame Temperature for Fuel Rich Combustion

I'm reading a combustion text and would like help interpreting the following passage (diagram attached). It is regarding the relationship between equivalence ratio and adiabatic flame temperature: ...
3
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1answer
61 views

A few basic questions about activation energy and the Maxwell-Boltzmann distribution

I understand activation energy to be the relative difference in energy between that of the activated complex/transition state (at some temperature) and the average energy of the reactants like shown ...
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61 views

Oxidation of formate ion by peroxydisulfate in water solution: Why are there “strange” kinetics?

As you can see, the first step is the slowest, but by using the rate-determining step approximation you wouldn't arrive at the correct rate law which is: $\ce{r=k[HCOO^{−}]^1^/^2 [S2O8^{2−}]}$. ...
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183 views

Complicated reaction mechanism

The reaction is this: The only idea I have thus far is if we have a chloride acid that can form an ester, then we might be able to find a suitable mechanism. This would require a chloride reagent.
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27 views

Synthesis of synthetic detergent with Friedel Crafts Acylation

I propose the following synthesis. 1) Oxidation of aldehyde to a carboxylic acid. This sets me up for FC acylation once I ... 2) Attack the -OH with thionyl chloride ad form the acid chloride. 3) ...
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19 views

Restricted synthesis; formation of nucleophile and electrophile from one carbon source

I am tasked by my textbook to synthesize 2-hexyne from 1-propanol. All carbon atoms must come from the starting material, 1-propanol. My solutions manual (an older version) does not have this ...
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83 views

Alllylic bromination of 1-butene

My book asks me to consider reacting 1-butene with NBS and light. I know that NBS and light leads to radical formation, and this is an allylic/benzylic bromination problem. However, my book only ...
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1answer
50 views

Alkyne formation from vicinal dihalide

Why must 3 equivalents of sodium amide be used here to form the alkyne? The part I specifically have issue with is in red. From what I understand, we should just use 2 equivalents of sodium amide to ...
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1answer
30 views

What is the chemical reaction in a home-made high-bouncer ball?

I took the kids to the Science Museum in Canberra (Questacon) and one of the toys we brought back was a Home-Made High Bouncing Ball. Now I did it with the kids and it was amazing. You pour the ...
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1answer
43 views

Allylic Radicals Bromination Mechanism

For (a) (iii), how do you get the second product listed in the answers manual? I just can't visualize it. What about (c) (i), why are there three resonance structures? If a hydrogen is taken away ...
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1answer
23 views

Syn Dihydroxylation of Alkenes

The answer makes sense to me. However, what if OsO4 were to attack from the other side of the double bond? Why does the answer key not show that possibility? Would we not get an other molecule?
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1answer
50 views

Nucleophilicity of bonding vs lone pairs

Does the bonding pair in $\ce{FeCl4^-}$ attack a proton or does a lone pair on the chlorine attack the proton? My prof has an argument for the first one; the first one involves fewer steps, so it ...
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33 views

Concerted hydride and alkyl shifts

I noticed while looking through a couple of books (specifically, Wade, Carey, and Vollhardt/Schore) that the mechanism of concerted hydride and alkyl shifts is always shown with alcohol leaving ...
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1answer
49 views

Method of allylic and benzylic oxidation

I am told that $\ce{MnO_2}$ oxidizes allylic and benzylic alcohols. However, what is the mechanism of this oxidation? All the professor had to offer me was that the metal ion, manganese 2+, chelates ...
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1answer
46 views

Free rotation of sigma bonds; diastereomer formation; thermodynamic and kinetic products

For the reaction of 1,3-butadiene with DBr (D = heavy hydrogen), I found that several possible products could be formed. Kinetic products A pair of enantiomers is formed. One of the pi bonds ...
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1answer
39 views

Sodium metal reduction of chloroform

In discussing how best to deuterate chloroform, it occurred to me that we could use sodium metal to reduce hydrogen into hydrogen gas. If this could actually happen, this would be a great thing - we ...
2
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1answer
64 views

Hydrogen and deuterium exchange

Is this a valid mechanism? I think it is. It is just a simple acid base mechanism. Could I increase yield though by using a stronger base than heavy water? Perhaps heavy sodium hydroxide? Or is ...
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1answer
41 views

The instability of hydrated carbon dioxide or “carbonic acid”

Why is hydrated carbon dioxide - the predominant form of acid that one gets upon dissolution of carbon dioxide in solution - so unstable? Is the below rationale valid? Carbon in carbon dioxide has ...
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2answers
70 views

Synthesis of 1-hexene from 1-octyne

This is my synthetic pathway. For one, is it plausible? For another, is it efficient? 1) Reduction of 1-octyne with hydrogen gas and Lindlar's catalyst to 1-octene. 2) Oxymercuration to install a ...
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1answer
118 views

2-methylpropene to tert-butyl alcohol Reaction Mechanism

Can someone explain what reaction is going on here? I looked in my list of mechanisms learnt: I find nothing related!
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1answer
64 views

Regioselectivity of Birch reduction (electron donating groups)

Why does Birch reduction on benzene derivatives with an electron donating group happen at ortho and meta positions? When the substitute is electron withdrawing, ipso and para reduction take place ...
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153 views

Can in any case the faster step of the reaction be rate determining?

I found a sentence in book which states the reverse step of this reaction ( I forgot what was it!) has the faster step as rate determining . Even Rate determining step-Wikipedia states: In ...
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3answers
239 views

Carbon decrease from 1-octyne to 1-hexene

I am to turn 1-octyne to 1-hexene. Method 1 1) Reduction using sodium metal in pure ammonia to an alkene. 2) Halohydrin formation; the -OH installs at the more substituted carbon due to its ...
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1answer
32 views

What reaction is expectable from the atomized reactants?

Let we have a reaction that starts from some reactants to produce some products. When the activation energy is provided to the reactants they will be atomized and produce a gas of individual atoms. ...
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1answer
53 views

Deamination of Spermidine?

I was making a solution of spermidine, and noticed that Sigma Aldrich warns that spermidine solutions deaminate over time. I tried to think of how that would happen, and made a diagram: Assuming ...
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1answer
80 views

Nitrosation of benzene

How does benzene react with $\ce{NaNO2/HCl}$? Will $\ce{PhNO}$ be obtained? I read that pyridine can be produced under special conditions, but what will happen in some less exotic conditions?
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69 views

Is this the correct mechanism of the formation of the nitronium (NO2+) ion from sodium nitrate and sulfuric acid?

I am currently working on a mechanism for forming paracetamol (or N-(4-hydroxyphenyl)-ethanamide). The typical reaction to nitrate the phenol (starting product) is $\ce{NaNo3}$ with a catalyst of ...
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487 views

Pedagogical exercise - How to synthesize methamphetamine

I am asked to synthesize "methamphetamine." Note that there is no configuration designated for this molecule, and methamphetamine refers to a very specific configuration. In any case, here are the ...
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165 views

Bromination Pathways with alkane, alkene, and alkyne substrates

I'm confused about halogenation pathways. From what I understand, there are multiple halogenation pathways. I'll try summarizing them below; let me know if I do anything incorrectly. Halogenation ...
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315 views

Nitrobenzene reduction with (tin) Sn catalyst: Why is C-H bond cleavage preferred over O-H bond cleavage?

I am trying to understand this mechanism for nitrobenzene reduction with $\ce{Sn/HCl}$. I do not understand why it implies that you pull off the $\ce{C-H}$ hydrogen instead of the $\ce{O-H}$ hydrogen ...
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1answer
81 views

HI/P reduction mechanism

I recently answered a question about Breaking Bad's initial methamphetamine production method (i.e. the reduction of (pseudo)ephedrine). The reaction is as follows: (Source: ...
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66 views

Causes of reversible reaction

It is generally said that reactants react so that they can achieve a lower energy state. Then why does a reversible reaction occur in the first place? Since turning reactants into products increases ...
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1answer
101 views

How does sulfuric acid dehydrate sugars?

I know sugars have -OH groups, and that sulfuric acid is a strong acid. What I'm failing to see is how exactly sulfuric acid dehydrates sugars. Does it protonate the hydroxyl groups, making them good ...
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1answer
56 views

Nitration of Aromatic Compounds

I am told by Dr. Klein that in the nitration of benzene, hydrogen sulfate anion acts as the base and deprotonates the sigma complex. My question is why would the hydrogen sulfate anion be doing ...
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1answer
40 views

Benzene Halide Sn1 Reaction?

Is such a reaction possible? Will the benzene carbocation be stabilized via resonance? Suppose the leaving group is super electronegative and the environment is protic. What would be a suitable ...
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1answer
88 views

Why is the addition of a singlet carbene to an alkene stereospecific? [closed]

Why is the addition of a singlet carbene to an alkene stereospecific, but not when a triplet carbene is added?
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4answers
84 views

How to figure out if the reaction proceeds via SN1 or SN2 mechanism?

I have been assigned with the task of figuring out whether a reaction is $\ce{S_{N}1}$ or $\ce{S_{N}2}$. The information that I have is, that the yield is dependent on solvent polarity. More ...
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2answers
98 views

Acid catalysed mechanism of the addition of alcohols to alkenes

I believe that this mechanism is false. The protonated ether would in my opinion give a proton to methanol rather than $\ce{H2SO4}$ because the protonated $\ce{CH3OH}$ is more stable than ...
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1answer
58 views

Catalytic iodine in synthesis of phosphonium salts

From Clayden et al. However, iodine is expensive and a way round that problem is to use a catalytic amount of iodide. The next phosphonium salt is formed slowly from benzyl bromide but the ...
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36 views

Mercury vapor release from amalgam fillings

What would cause vapour release from elemental mercury? Would it be pressure, friction... could one stop the vapour release through cooling the mercury?
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1answer
46 views

2,2,6,6-Tetramethylpiperidine - Bronsted Basicity

I understand that this molecule can only act as a Bronsted base because it is sterically hindered by its multiple methyl groups. However, isn't the proton bound up in solution? Doesn't that ...
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1answer
40 views

Ethene to ethanol: electrophillic additions involving ethyl sulfates

http://www.chemguide.co.uk/mechanisms/eladd/symh2so4.html I was reading my textbook and this website. I just cannot find the mechanism for what happens when we go from CH3CH2OSO3H to ethanol by the ...
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Synthesis via Sn2/Sn1, E2, E1: Choice of solvent

I uploaded pictures on http://www.physicsforums.com/showthread.php?t=765106 I was looking at the answers in my textbook. They seem to make incongruent choices of solvents. In e) and j), why choose ...
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1answer
32 views

Reaction of alkyl halides with strong unhindered bases

Please look at the image on this website: http://www.physicsforums.com/showthread.php?t=765853 For (b) and (c), what the solution manual says makes no sense to me. You're reacting a primary alkyl ...
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22 views

Can anyone explain the reaction mechanisms of these synthesis?

Can anyone explain the reaction mechanism of the following synthesis ? 2NH4Cl + Ca(OH)2 --> 2NH3 + 2H2O + CaCl2 (NH4)2SO4 + 2NaOH --> 2NH3 + 2H2O + NaSO4