Questions tagged [organic-chemistry]

Use this tag for questions relating to organic molecules and their properties (structure of organic molecules, spectroscopic properties, reaction mechanisms, stereochemistry etc). DO NOT use this tag as the only tag in your question, as this tag by itself cannot appropriately classify your question. Always use this tag in addition to other more specific tags.

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Why is o-fluorophenol a stronger acid than p-fluorophenol?

The $\mathrm{p}K_\mathrm{a}$ value of o-fluorophenol is $8.7$, while that of the p-fluorophenol is $9.9$. It's obvious that the inductive effect is more dominant at ortho-position, which results in a ...
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Why does the presence of EWG's on the aryldiazonium ring increase the yield of a Meerwein arylation?

In my textbook, Strategic Applications of Named Reactions in Organic Synthesis, the author says the following regarding properties of the Meerwein arylation: The general features of this reaction ...
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Using Ethylene Glycol as anti-freeze in a biodigester gas storage system

I am busy building a bio-digester to produce biogas for cooking/water heating in a cold climate. I am using the 3 IBC tank solution. Tank 1 is the digester itself. Tank 2 is the gas storage unit. ...
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How would you measure the rate of this SN1 reaction?

I am performing the following $\mathrm{S_N1}$ reaction: $$\ce{t-BuOH + HCl -> t-BuCl + H2O}$$ I would also like to measure the rate of this reaction, but I cannot seem to find a way. I initially ...
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Treatment of ketones with excess Tebbe reagent

The reaction in black below was presented in a set of lecture notes as an example of the use of the Tebbe reagent, however it's not immediately obvious (to me, at least) that the product should be the ...
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Reaction of fumaric acid and performic acid

Performic acid ($\ce{CH2O3}$) has strong oxidizing properties. So when it reacts with fumaric acid, is this the product (2,3-dihydroxybutanedioic acid) that I should expect?
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Do both NH2 groups in semicarbazide have the same properties?

Would it be correct to consider both the hydrazine and amide $\ce{-NH2}$ groups in semicarbazide (hydrazinecarboxamide) as derivatives of ammonia? I thought about this possibility while writing the ...
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What is the degradation mechanism of pyrrole?

A vial of pyrrole (that was occasionally exposed to air) changed its color while degrading from pale yellow to dark orange. What is the mechanism of pyrrole degradation? What are the resulting ...
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How big is the gauche interaction of methyl with phenyl in a disubstituted cyclohexane?

I'd like to compare the equatorial 1-methyl-2-phenylcyclohexane conformation of with axial conformation of 1-chloro-3-methylcyclohexane conformation. In which molecule there is less steric repulsion? ...
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Lemieux-Johnson oxidation on cycles

Consider 5-cyano-2,2-dimethylpentyl 4-methylbenzene-1-sulfonate: What would it yield by a Lemieux-Johonson oxydation ($\ce{OsO4}$, $\ce{NaIO4}$)? My first guess would have been that $\ce{OsO4}$ was ...
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Dissolving ability of octane vs nonane on neoprene

I have been working with straight chain octane and nonane. The neoprene seals in some parts of the apparatus are allegedly far more vulnerable to the deleterious effects of octane than nonane - why? [...
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Methylation of perchlorate

I am exploring (non-experimentally!) the methylation of a perchlorate precursor, either the acid or pre-existing salts, to produce the alkali methyl perchlorate. The methylating agent would be methane ...
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In the Haworth projections of D and L glucose, is the stereochemistry at every carbon except the anomeric carbon just inverted?

I'm having a bit of trouble grasping sugar stereochemistry. Using glucose as an example, if you cyclize D and L glucose, is the stereochemistry at every carbon just inverted from the other form? ...
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Orientation in benzene rings with more than one substituent

Why is it that the chlorination of 1-chloro-3-nitrobenzene (18) gives 1,4-dichloro-2-nitrobenzene (19) as the major product, 1,2-dichloro-3-nitrobenzene (20) as a minor product and 1,2-dichloro-4-...
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How did the first amino acids appear on Earth?

Is there proof or a theory that shows that the first amino acid syntheses on Earth were influenced by a change in heat, gravity, radiation, or something similar?
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Is it possible to do Cobalt catalyzed directing group asisted meta C-H functionalization of arenes

Directing Group assisted Pd catalyzed (sp2)meta-C-H functionalization has a growing attention in recent years. In addition, few examples can be found for meta-C-H functionalization via Rhodium. I am ...
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Does π values vary in Hansch-Fujita equations for a given substituent?

I was reading about Hansch-Fujita equations from Hansch-Fujita paramaters and observed that the $π$ values of substituents (analogous to Hammet $σ$ values) change according to the specific environment ...
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Why are S-thiocarbamates less toxic than carbamates?

According to Haley and Rhodes, neostigmine bromide (alternatively known as Prostigmine) has an LD50 in mice of around 0.165 mg/kg by IV injection. Pubchem claims that this is also the LD50 for ...
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Optical activity of tartaric acid

The meso-form of tartaric acid is optically inactive due to the plane of symmetry. But how are these forms able to show optical activity when the σ-bonds can freely rotate, which can change the ...
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Wittig reagent with metal–oxo bonds

Could you use the Wittig reagent to attack a metal–oxo bond and replace the oxygen with a carbene? Specifically, is it possible for the Wittig reagent to do σ-bond metathesis with an electrophilic ...
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How do bonds rotate in pericyclic reactions?

In Pericyclic reactions, it is shown that the terminal bonds rotate (conrotation or disrotation) to allow for allignment of the FMO's, thereby forming the sigma bond However, a detail that most of my ...
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The best way to designate unsaturation (double bond)

Although it has already been explained here that the use of the "Δ" (Greek capital delta) character is not recommended to designate unsaturation in individual names, IUPAC 1989 Nomenclature ...
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Reaction of 1,3-dibromobutane with zinc dust upon heating

I've studied that when 1,3-dibromopropane (or in general any halogen, not just bromine) is heated with Zn dust, the electrons produced cause the halogens to break away homolytically and two free ...
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Geometry of a free radical at the bridgehead carbon

With reference to J. Am. Chem. Soc. 1968, 90 (19), 5266–5267, they state: The most favorable geometry of aliphatic free radicals remains an unsolved problem, since existing data are consistent with a ...
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How much oxygen is used up by the browning of an apple?

This is inspired by a recent popular question on Cooking. Let's assume that I take some apples, cut them up, and place them in a hermetically sealed container. Then the container goes into the fridge. ...
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What drives the 'internal return' in SNi?

I just learnt that alcohols can undergo $\mathrm{S_N}i$ with $\ce{SOCl2}$ (without pyridine) to achieve retention: However, what I really do not understand is the 'internal return' step (forming '...
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Interaction of trifluoroacetates with acetylcholinesterase

There exists a substance called TMTFA, or 3-(N,N,N-Trimethylammonio)-2,2,2-trifluoroacetophenone. It is known for being able to inhibit acetylcholinesterase at femtomolar concentrations. The TMTFA-...
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Distilling milligram quantities of oil like it's late 1970s

In a currently retracted* manuscript by Tomas Hudlicky [1, Retraction Watch] the following has been noted: Fifty years ago professors took an active part in all laboratory instructions and they ...
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120 views

Why isn't PBr3 used to halogenate tertiary alcohols?

I've been looking into activation of alcohols for nucleophilic substitution, and I've come across a series of reactions that differentiate between primary, secondary and tertiary alcohols. I've seen ...
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The IUPAC name of a multifunctional carboxylic acid compound

What is more preferred name when ester is present as junior functional group bis-carboxylic acid? (refer the image attached): to count carbon of ester and consider two branches on it (one oxo and ...
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Is it possible to estimate the abundance of conformers from J values?

I have a system of two disubstituted cyclohexanes and I want to estimate the abundance/ratio of the two based on the J values and if possible, roughly estimate the difference in free energy. To get ...
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Specific reduction of certain functional groups

Consider the compound $\ce{Alkyl-(4 oxocyclopent-2-ene)carboxylate (A)}$. For example consider- Now consider the operations: $\ce{1. (A) + (i)BH3/THF (ii) H+}$ $\ce{2. (A) + H2/Pt}$ ...
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How is NaBH4 able to reduce tertiary alkyl halides to alkane but LiAlH4 create an alkene?

When attacking tertiary alkyl halides, aren't both of them just supposed to follow $\mathrm{S_N2}$ and substitute the leaving group with Hydride ion? Apparently only $\ce{NaBH4}$ does it and $\ce{...
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What makes this molecule achiral?

I don't understand why this molecule is achiral: I've circled what I think is the sole chiral center in red. I thought that any molecule with exactly one chiral center is chiral without exception. I ...
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Can a per-acetylated sugar anomerize?

So I have a question concerning a reaction mechanism for the reaction below. I know for certain that I get the alfa anomer, but I can't explain it. When I draw out the mechanism it doesn't make sense ...
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An unknown glassware piece from our cupboard

We have multiple of these. It is a small glass funnel with splits into 3 spouts from it. Now, we are thinking it might be similar to a cow receiver, however, I have never seen one this small or ...
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Stability of carbocation

While comparing the stability, as the $\ce{CH3}$ group is electron donating, the first structure should be more stable due to this reason. But apparently the second one is more stable. Is there ...
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Shouldn't the 5-membered ring expand to a six membered one in this nucleophilic addition reaction?

I am dealing with a problem involving addition of $\ce{HCl}$ to a ring: According to what I think, the ring should expand to a six-membered following carbocation formation at the tertiary site, as a ...
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635 views

Is there an advantage to the Clemmensen or Wolff-Kishner reductions over the Mozingo reaction?

As I understand it (and please correct me if I'm wrong), ketones and aldehydes can be reduced to methylene derivatives via: Clemmensen Reduction (acidic conditions): Wolff-Kishner Reaction (basic ...
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555 views

Why is bis(1,2,2,6,6-Pentamethyl-4-Piperidinyl) Sebacate used as a “bottom coat” for a superhydrophobic coating?

According to this MSDS sheet, a compound named bis(1,2,2,6,6-Pentamethyl-4-Piperidinyl) Sebacate is used in the "bottom coat" layer before a "top coat" of superhydrophobic NeverWet coating is applied. ...
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Why is the carbon atom omitted from the molecular formula?

In my chemistry textbook, the following reaction was given: I have two questions related to the marked in orange boxes/parts of the image: Why is the molecule symbolized by $\ce{(CH3)3Cl}$ instead ...
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Reaction of cyclopropane with hot potassium permanganate

Hot potassium permanganate is usually used as an oxidising agent, and cyclopropane being an unstable three membered ring undergoes reaction with several reagents such as bromine, $\ce{HBr}$, metal ...
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Reactivity of carbon-centered radical

I've read this site for a long time but I had never asked a question, so this is my first time :). So, i'm currently working on a computational chemistry project on radical cyclization reactions and ...
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What makes the first 3 alkanes decrease in melting point while after that they rise?

What makes the first 3 alkanes decrease in melting point (m.p.) while after that they rise? $$ \begin{array}{lr} \hline \text{Alkane} & \text{m.p.}/\pu{°C} \\ \hline \text{Methane} & -182 \\ \...
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Is the haloform reaction possible with fluorine and pseudohalogens also?

The haloform reaction is: $$\ce{RCOCH3 +3X2 +4OH^- -> RCOO^- +CHX3 + 3X- + 3H2O}$$ where, $\ce{X}$ is $\ce{Cl}$, $\ce{Br}$, or $\ce{I}$. However, I was wondering if this reaction works with ...
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Why do t-butyl bromide and silver(I) nitrite form the nitroalkane, not the nitrite ester?

We know that reaction of $\ce{AgNO2}$ with alkyl halides is SN1 type reaction and follows HSAB principle. So in the reaction of $\ce{(CH3)3C Br}$ we would expect $\ce{AgBr}$ to form and also a ...
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An interesting oxonium ion

On p. 429, when introducing the idea of bromonium ions, Clayden et. al.[1] mention that: You can think of the bromonium ion as a carbocation that has been stabilised by interaction with a nearby ...
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Which site is more favorable for EAS in O-Acetotoluidide?

Which site is more favorable for electrophilic aromatic substitution in O-Acetotoluidide? The answer given in my textbook says the site para to acetamide group is more favorable, however I believe ...
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293 views

Stability of extended enolates

I'd expect an extended enolate to be more stable than a normal enolate, when both can form, but my textbook suggests otherwise. What is the stability of an extended enolate compared with a normal ...
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Platt's Notation/Nomenclature for transitions

How do you read Platt's Notation / Nomenclature? Where can I learn this? Some examples where I've seen this mentioned: In Platt's notation the transitions are designated as $\ce{A -> B}$ and $\ce{...

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