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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The most acidic hydrogen of 4‐hydroxybutanenitrile
Identify the most acidic hydrogen atom in the compound below:
$$\ce{NC-CH2-CH2-CH2-OH}$$
My teacher said that the $\ce{H}$ connected to $\ce{O}$ is the most acidic since $\ce{O}$ is more ...
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Diastereoselectivity of the Pauson Khand Reaction
I hope someone may help me. I don‘t know how to determine the diastereoselectivity of the product of the Pauson Khand reaction in generally.
In the following I’ve got 3 practice examples,however in ...
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Volatility comparison for isomers of phthalic acid
All the atoms of these compounds are in a plane.
o-phthalic acid can show extensive intra-molecular hydrogen bonding as well as inter-molecular hydrogen bonding.
m-phthalic acid can show intra-...
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Dipole moments of dibromoethene isomers
There was an exercise in my textbook asking to compare the dipole moments of 1,1-dibromoethene and 1,2-dibromoethene(Z). The answer in the textbook says that the dipole moment of 1,1-dibromoethene is ...
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Enantiomeric excess catalysed
Enantiomeric excess is defined as
$$ee = \frac{[R]-[S]}{[R]+[S]}$$
I found this problem in an IChO paper:
"When using the enantiomerically pure (BINOL)Al(OiPr) as a catalyst for reduction of ...
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Why do some compounds without carbonyl group give positive 2,4-DNPH test?
I was performing some experiments in Chemistry Lab today in which I had to find the functional groups present in a compound.
It being a very basic undergraduate course introducing us to the ...
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How ethylbenzene and 1,2‐xylene are chain isomers?
How the following two structures are chain isomers?
According to what I have studied in nomenclature when a compound has both cyclic and straight chain, we consider that the chain as parent chain ...
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Reduction of ester / eneone in presence of epoxide
I want to reduce an ester and an eneone in the presence of a terminal epoxide.
I read on here @jerepierre did an ester in the presence of an epoxide with DIBAL.
I know the DIBAL works for my ester, ...
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Question on identification of a compound
Question:
Multiple correct answers are possible
My Approach:
I just found structure Q for all options A, B, C and D for which I have uploaded the structures below with their corresponding options.
...
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249
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Diketone intramolecular reaction question
I realize that one of the methyl groups on either carbonyl compound will become deprotonated and then it will attack the other carbonyl to form a pentane ring. However, with the methyl group in the ...
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Is the 1,4-adduct of carbonyl compounds ever a major product over the 1,2-adduct?
If, say, propenal undergoes nucleophilic addition of hydrazine, will the 1,2- adduct or the 1,4-adduct be preferred? Why?
There is an obvious reasonace structure with an electrophilic beta carbon so ...
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How to remove the foggy discoloration in polycarbonate tubes caused by acetone?
Unknowing that the tubes used in the centrifuge are made of polycarbonate, I cleaned them with acetone. Following, a white smoky discolouration appeared and the tubes turned opaque. Is there any way ...
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578
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Mechanism of Bis-decarboxylation of α,β-dicarboxylic acid
According to an internal test series in FIITJEE, it was given that the following compound decarboxylates on heating,
I know that β-keto acids undergo decarboxylation on heating, but I was not sure ...
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Will a Lewis acid catalyze the reaction of HBr with primary alcohols?
It is well-established that a Lewis acid catalyst (popularly $\ce{ZnCl2})$ is necessary to form an alkyl chloride when reacting $\ce{HCl}$ with a primary alcohol. This actually changes the mechanism: ...
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Number of aromatic rings in triphenylene
My question is how to find the number of aromatic rings in triphenylene:
My professor said that there are 3 aromatic rings, after which he added that the carbons of the middle rings are only ...
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Last steps of mechanism of Swern Oxidation
My question is regarding Swern oxidation. Why is the methyl group of the DMSO deprotonated and not directly the red hydrogen atom of the R2-CH-O bond deprotonated? Shouldn't it be that oxygen more ...
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Investigating the effect of solvents on the alkaline hydrolysis of ethyl acetate
In the following reaction, I believe a polar aprotic solvent like propanone will be more favorable since the partial negative charge on the oxygen atom in propanone will attract the sodium ion from ...
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Which of the following groups show +M and -I effect?
Which of the following group show +M and -I effect?
(A) $\ce{-\underset{\underset{\huge O}{||}}{C}-F}$
(B) $\ce{-\underset{\underset{\huge O}{||}}{C}-OR}$
(C) $\ce{-O^-}$
(D) $\ce{-OH}$
Answer is ...
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293
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Product of Diels-Alder reaction + Consecutive Reaction with base and heat
there is a problem regarding a Diels-Alder reaction that I do not understand (see image).
The Diels-Alder reaction of the diene and the dienophile should lead to the product A. I hope I did it ...
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Investigating the effect of solvents (protic vs aprotic) on the alkaline hydrolysis of ethyl acetate using a conductivity meter
What different areas about solvents can be explored with the conductivities collected of the alkaline hydrolysis of ethyl acetate in propanone and ethanol?
$$\ce{CH3COOC2H5 + NaOH -> CH3COONa + ...
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How do you purify phosphoric acid from cheap commercial (hardware-store) products?
I am looking for idea's on how to purify phosphoric acid for lab use, as the the price for reagent grade V's home-use ended with me buying a product designed as a rust-killer for steel... The ...
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What makes determining entropy changes theoretically so hard compared to enthalpy?
It is really hard to determine the entropy change of a reaction accurately because of subtle solvent effects and a lack of standard entropies. On the other hand, enthalpy is relatively easy and ...
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How do blue shifts in Raman spectra indicate a co-crystalline compound?
The short conference paper The Acetylene-Butane Co-Crystal: A Potentially Abundant Molecular Mineral on Titan (mentioned in EurekaAlert's 'Bathtub rings' around Titan's lakes might be made of alien ...
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Why isn't the base reformed in base-catalyzed hydrolysis of esters?
In acid-catalyzed hydrolysis, the hydronium ion is clearly reformed; however, in the base-catalyzed hydrolysis, an alcohol is formed as a by-product, but the strong base isn't reformed. Is it a ...
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Comparing the emission spectrum of ethanol and mixture of alcohols
Sorry if this question has a simple answer, but I've been unable to find it elsewhere.
Using a diffraction grating, burning ethanol (99.9%) will produce a rainbow of colours. However, when burning ...
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Polar Protic and Aprotic Solvents
I know $\mathrm{S_N2}$ is favored polar aprotic solvents, which means that they may have hydrogens on them somewhere, but they lack $\ce{O-H}$ or $\ce{N-H}$ bonds, and therefore cannot hydrogen bond ...
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77
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Aldol Reaction on an intermediate
I was given the following reaction to prove a mechanism for:
and I managed to prove the first step with ease.
The second step, forming the "base-catalysed aldol" is the part that's rather confusing ...
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Robinson annulation
In the mechanism of Robinson annulation, what is the rate determining step?
I have searched in my book but it is not given. If possible please specify the reason for that step being the RDS.
Thanks in ...
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Does boric acid catalyze esterifications with isopropanol?
I am going to synthetise isopropyl salicylate. From what I have read on phillysim.org (pdf) the formation of ethyl salicylate can be catalyzed by boric acid. I could use sulfuric acid but it would be ...
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Number of hyperconjugative structures in aromatic systems
I know that to find the number of hyperconjugative structures in aliphatic systems we use the formula $a + 1$ (where $a$ is the number of α-hydrogens in that compound)
However, my teacher answered ...
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Why is the nucleophilic substitution of OH- with 1-bromopentane slower than with 2-bromo-2-methylbutane?
Which statement about the reaction of a hydroxide ion with the organic reagent is correct?
A. 1-bromopentane predominantly follows an $\mathrm{S_N1}$ mechanism.
B. 2-bromo-2-methylbutane predominantly ...
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775
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1,4-addition vs 1,2-addition aldol/aldol type reactions
In the aldol/cross aldol reaction, of $α,β$-unsaturated carbonyl compound, under what circumstances does a 1,2-addition i.e. aldol condensation (carbanion formed directly attacking carbon of carbonyl ...
- 1,027
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Why is only one of the lone pairs on the oxygen in furan delocalized?
Both the lone pairs on the oxygen are in allylic positions, thus both should be able to participate in resonance. If both lone pairs can participate in resonance, why is only one of the lone pairs ...
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How does HCl break down amylopectin in starch into amylose?
I'm currently researching on manufacturing bioplastics. During one of the steps, HCl is added to break down amylopectin into amylose, but I don't understand how exactly this happens. It would really ...
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Reaction of Br2/KOH with succinic anhydride
What products will be formed when $\ce{Br2/KOH}$ reacts with the following compound in water at room temperature?
Here is what I think is possible:
$\ce{OH-}$ will take up the acidic hydrogen.
$\ce{...
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Does Raney nickel deprotect acetals?
I know that Raney nickel can deprotect thioacetals. Can it deprotect acetals as well?
I found this image which shows that it deprotects and removes many protecting groups. But there was no reference ...
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Find the increasing order of formation of ortho product
Find the increasing order of ortho product formation when Y is (i) F, (ii) Cl, (iii) Br, (iv) I.
We know that halides are ortho, para directing for EAS reactions and we consider the electronic ...
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Kinetics for E1cb reactions
We were taught that the kinetics of a reaction is determined by the reactions ‘rate determining step’ which is also the slowest step of the reaction. For E1 as well as E2 reactions the slowest steps ...
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How is a ring formed when a carbon atom in an aliphatic chain attached to benzene ring has a positive charge?
This is my approach towards this problem. First off, a positive charge would appear in the C atom at the end of the chain, and then that carbocation would rearrange into a tertiary carbocation.
But I ...
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Potassium ethoxide
Is it possible to make potassium ethoxide by mixing $\ce{KOH}$ and $\ce{EtOH}$ in the presence of a dehydrating agent like $\ce{MgSO4}$ or $\ce{CaO}$ or $\ce{K2CO3}$?
The easy way is adding metallic ...
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Distinguishing between a nucleophilic substitution and an electrophilic substitution
Why don't we consider all nucleophilic substitution reactions as electrophilic reactions and vice versa?
For example, look at this reaction I found in my textbook. (See picture)
This is an ...
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Determination of the most acidic hydrogen in an organic compound
Identify the most acidic hydrogen in the compound below:
Can someone please explain why is $\ce{H^\mathrm{a}}$ in the compound below more acidic than $\ce{H^\mathrm{b}}$?
This is what is written in ...
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Resonance in a non-planar molecule
I am well aware that the following compound is non-planar and hence, will not be anti-aromatic but non-aromatic.
But I wonder whether resonance will occur to some extent i.e. whether any three ...
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How to acetylate a thiol group in general?
I wonder (and have tried to find the answer by searching in synthetic chemistry resources) how do you acetylate thiol (R-SH) groups in general? For example the cysteine-SH group either alone to make S-...
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How many moles of methyl iodide will be consumed by one mole of crixivan?
My take on this question : a total of 5 moles of $\ce{CH3I}$ should be consumed.
The oxygen atoms in the $\ce{2 OH}$ groups each have a lone pair of electrons. They should displace $\ce{I-}$ from ...
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How to recreate bioluminescence in fireflies in a lab?
I have several mg/mL of D-luciferin, luciferase (firefly), ATP solution (25 mmol) and MgSO4 (for the mg2+ ions). The experiment has to be done in cuvettes of 2,5 mL (if I get any results, it will be ...
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279
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Iodoform on acetone gives one product?
During the Iodoform reaction of acetone why does the second iodine addition happen on the carbon that already has undergone substitution instead of the other carbon?
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Antiaromaticity can be explained by Hückel method?
Pentalene is one of the most famous antiaromatic molecules. But I obtained its energy of $\pi$ system as $8\alpha+10.46\beta$ by Hückel method (with a bit complicated but straightforward calculation). ...
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Deuteration of following enone - mechanism?
What happens when the above compound is subjected to DCl in MeOD? As a result of tautomerism, I'd expect at least 7H atoms, two alpha to carbonyl carbon (right side), and five at gamma position (two ...
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Predicting the products obtained after addition of bromine and then elimination using alcoholic KOH
If we have an alkene reacting with bromine, then I know that the the reaction happens by a cyclic intermediate. But if we add alcoholic KOH to the products formed, then what will be the major products ...
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