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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Can the nitrogen of an amide displace a primary chloride in a S_N_2 reaction in the presence of a strong base?

I was looking at the following reaction and am confused. It appears that $\ce{N}$ is attacking the $\ce{C-Cl}$ and $\ce{Cl}$ is leaving in a $\mathrm{S_N2}$ reaction. I know that $\ce{Cl}$ is a good ...
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434 views

Diazo Coupling reaction with para-substituted phenol?

Usually Diazo coupling occurs at para-position unless the para-position is occupied, in which case coupling occurs at ortho-position. While solving questions I found in both the cases as shown, the ...
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185 views

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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309 views

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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23 views

Analytics of a paramagnetic complexes

I am working with salophene iron[III] complexes. Unfortunately, my 5th ligand cannot be determined via MS. I performed a 1H-NMR in methanol, but it's not a suitable method for a paramagnetic compound. ...
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42 views

Rationalising diastereoselectivity of hydroboration using stereoelectronics

Using bulky reagents such as 9-BBN, hydroboration is often highly diastereoselective, giving rise to the 1,2-anti diastereomer: This is easily explained using a steric argument, with the major ...
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270 views

Reaction of alpha hydroxyketone with KOH

What happens when 2-hydroxycyclohexan-1-one (an alpha hydroxyketone) reacts with aqueous $\ce{KOH}$? I tried something like Favorskii rearrangement, but it's wrong because OH isn't a good enough ...
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1k views

Why is [Fe(CN)6]4- colored and at the same time diamagnetic?

While I was studying Chemistry, it came to me wondering why $\ce{[Fe(CN)6]^4-}$ is colored and at the same time diamagnetic. For a transition metal to be diamagnetic all the electrons should be paired ...
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71 views

Activation of alcohols by forming sulphonate ester

In activation of alcohol by tosyl chloride, why does the chloride ion not displace the poor leaving group? I think that's because chlorine is a poorer base than that thing which will be formed. But ...
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325 views

Mechanism for reaction of enol ether with HBr

Please refer to the image for the question. I tried two different mechanisms for the reaction (1 and 2) and ended up with two different products. Now I can't decide which of the two mechanisms would ...
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604 views

Hydrogen bond strength of trichloromethane and chloromethane

Chloromethane has a larger dipole moment than trichloromethane. Does that mean that the hydrogen bond (C-H...O type) between chloromethane and acetone is stronger than that of trichloromethane and ...
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171 views

What is a good solvent for pentacene?

I am doing an experiment with pentacene molecule ($\ce{C22H14}$). I want to clean my sample reservoir after using it. But I show in some literature that it is slightly soluble in organic solvent. ...
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99 views

Directing nature of the -SOR substituent in electrophilic aromatic substitution

This is (alkanesulfinyl)benzene: I didn't draw it, but we know that the sulphur atom also has a lone pair. So, the sulphur atom can increase electron density in the ring by donating a lone pair. ...
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248 views

Sigma bond behaving as stronger nucleophile despite presence of pi bond?

In my book, the following reaction is given The solution states that the sigma bond between hydrogen and carbon (3 degree) in isobutane attacks $\ce{H+}$ from $\ce{HF}$ to generate tert-butyl ...
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234 views

Substitution of a cyclic diether by a halogen

I’m in an organic synthesis class and I have to draw a mechanism for the reaction in the picture. At first I thought it was just forming a free radical but I haven’t been able to find any way to do ...
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125 views

Rationalise the Relative Reactivity of Borane and DIBAL as Reductants

In Clayden's Organic Chemistry (Second Edition) it is written that borane is useful in chemoselectively reducing the most nucleophilic carbonyl to its corresponding alcohol. It is later said that ...
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724 views

Comparison of the rate of SN1 and SN2 reaction

It is known that $\mathrm{S_N1}$ (Substitution Nucleophilic Unimolecular) follows the order of rate of reaction: Tertiary ($3^\circ$) > Secondary ($2^\circ$) > Primary ($1^\circ$) For $\mathrm{...
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211 views

Why is this step exothermic?

From Wade's "Organic Chemistry" [1, p. 1003-1004]: MECHANISM 21-7 Conversion of an Ester to an Amide (Ammonolysis of an Ester) Step 2, loss of a poor leaving group is justified by claiming ...
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3k views

Which is the correct mechanism for the ozonolysis of an alkyne?

According to Organic Chemistry by Jonathan Clayden, Nick Greeves and Stuart Warren (2nd edition), the mechanism for alkene ozonolysis is given as In Advanced Organic Chemistry, Part B: Reactions and ...
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208 views

Reaction of bicyclic diol with periodic acid

I'm in an organic 1 class, and we learned about using periodic acid (HIO4) to cleave a glycol into two carbonyl groups, oxidizing the glycol. However, in the given reaction (see picture below), I'm ...
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72 views

Kinetics of nitric oxide production

Several articles affirm that NO can enhance the glutamate release from the presynaptic site; moreover, glutamate has been recognized as a major brain neurotransmitter and is considered to mediate ...
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191 views

Waterproofing and recycling paper

I've recently begun studying about waterproofing paper. Through what I learned is that the reason why paper absorbs water so easily is mainly because of it's material composition. Paper is generally ...
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465 views

Number of intermediates and transition states in hydration of given alkene

What is the number of transition states and intermediates formed in the following reaction? My thought: First the alkene extracts $\ce {H^+}$ from the acid to form a carbocation. This step involves ...
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51 views

Pd-catalysed hydrogenation of imines

Hydrogenation of imines to amines by $\ce{H2}$ on $\ce{Pd/C}$ has been used e.g. in the synthesis of Pumiliotoxin. By contrast, carbonyl groups are rarely reduced in this way, which I though was due ...
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In-vivo racemization of thalidomide

In 1961, thalidomide was first introduced as an over-the-counter cure for morning sickness. Pregnant women across the country began to take the drug, which worked well, but shortly after, babies began ...
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4k views

Why is enol content higher in non-polar solvents?

Apparently, for keto-enol tautomerism, the enol content of a given carbonyl compound increases when in a non-polar solvent. What is the reason for this?
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312 views

Mechanism for conversion of gem-dihalide to carbonyl compound

How does nucleophilic substitution work in a compound consisting of two leaving groups? I understand that hydroxide ions will attack the carbon centre (which bears a partial positive charge) and ...
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247 views

On the directing nature of these groups in electrophilic aromatic substitution

These three groups are listed in our workbook. I don't know the answer and our teacher isn't sure either: (each has a free valency through which it is attached to a benzene ring): ...
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128 views

Why is dimethylmercury more toxic (to animal life) than methylmercury or ethylmercury?

It's obviously a two step process to reduce dimethylmercury to the less harmful inorganic form. Is neuronal uptake also enhanced due to lipophilicity? Is there some other mechanism of toxicity I'm ...
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89 views

How can I test fruits and vegetables for certain insecticides?

I live in Turkey and I don't feel safe eating the fruits and vegetables that I enjoy that are plentiful here. After reading this article, I have been washing all fruits and vegetables with water and ...
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58 views

Nucleophilic substitution of 2-chloropropanoyl chloride

Upon heating 2-chloropropanoyl chloride with concentrated ammonia in a sealed vessel, a primary amide is formed but the chlorine atom at the beta carbon does not get substituted with an amino group, ...
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70 views

Should I add more of a trihydrate chemical to a solution if recipe calls for hemihydrate?

I am running phosphate by the ascorbic acid method (SM 4500-PE, PDF), and making the antimony potassium tartrate reagent. Standard methods uses $\pu{1.3715 g}$ of $\ce{K(SbO)C4H4O6 * 1/2 H2O}$ per $\...
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180 views

Why does viscosity decrease when divalent cations are dissolved into aqueous solutions of sodium carboxymethylcellulose?

Sodium Carboxymethylcellulose (CMC/NaCMC/Aqualon) is a common product used in many instances for its unique properties, especially its ability to make solutions viscous. It is well known that the ...
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58 views

Thyroid peroxidase - can atomic iodine serve as iodinating agent?

McMurry's Organic Chemistry (7th Ed.) states, that Tyrosine is iodinated by mechanism of electrophilic aromatic substitution and the iodinating agent is $\ce{I+}$ or $\ce{HIO}$ formed by thyroid ...
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146 views

Expedient phosponium synthesis (for Wittig)

I have been making ethyltriphenylphosphonium bromide (somewhat of a time crunch, would have used iodoethane instead of bromoethane if we didn't have to wait for it). All the syntheses I see of Wittig ...
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46 views

Is optical activity of a given compound a statistical picture?

When optical activity is taught it is done in terms of single molecules. But when it is actually measured it is done on a large collection of such molecules. So, how does the asymmetry manifest itself ...
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2k views

Reactivity of meta and para xylene towards nitration

Is meta xylene more reactive towards nitration or is it para xylene? I would say it is meta xylene as it has two methyl groups meta to each other. Since both are activating groups, there would be a ...
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136 views

[3+1]-Cycloadditions of Sulfur Ylides and 1,3-Dipoles(?)

My question is basically regarding the stereoselectivity of the situation. I am not being able to decide on the positioning of the sulfur ylide with proper justification. In the attached hand-drawn ...
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1k views

On baker nathan hyperconjugation

Recently I have been reading about the history of the Baker Nathan reaction. In addition to the large rate increase for Me vs H, all the other alkyl groups showed decreases with respect to Me ...
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0answers
2k views

How does Lindlar's catalyst work?

I can not find a mechanism online. I understand that some poisoning effect causes the catalyst to be unable to reduce an alkene to alkane; however, if the catalyst is poisoned, how does it continue to ...
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218 views

Hammett plot shape: dependent on substituent or mechanism?

So, we were shown a Hammett plot that, on the left was linear, but on the right was concave up. How would I explain the shape of the Hammett plot? Does it depend on whether the substituent is an EDG ...
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648 views

Oxidation of dihydropyridine

This is a step in a experiment I have carried out. Usually DDQ (dichlorodicyanoquinone) would be used here to oxidise the dihydropyridine. However in this case Nitric Acid is being used as the ...
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508 views

Sodium Naphthalenide

The sodium fusion test done in the lab for the systematic identification of a given organic compound is basically fusing sodium metal in a fusion tube, and then adding the compound in a small quantity,...
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619 views

Experimentally proving the mechanism and rate laws of SN1 & SN2 reactions

I have been given the task of experimentally proving the rate laws and mechanisms of $\mathrm{S_N1}$ and $\mathrm{S_N2}$ reactions. Unfortunately, the only equipment I can use is limited to analytical ...
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473 views

Why doesn't beta hydride elimination happen in alkenyl/aryl halides?

Beta hydride elimination is an important reaction in organometallic chemistry: This reaction prohibits the use of saturated alkyl halides in coupling reactions, because it can take place after ...
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161 views

Stability of unsaturated syn/anti 3-ladderane

In an oral exam for physical organic chemistry, one student was asked to explain the differences in the ionization potential ($IP$) of syn and anti tricyclo[$4.2.0.0^{2,5}$]octa-3,7-diene (unsaturated ...
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137 views

Asymmetric Suzuki coupling - saturated alkyl chain

9-BBN is applied for Suzuki coupling of a saturated alkyl chain with some alkenyl,alkynyl or even secondary alkyl halide like the modification attached: (Saito, B.; Fu, G. C. Alkyl−Alkyl Suzuki Cross-...
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335 views

Regioselectivity of the Beckmann rearrangement

It seems to be that the Beckmann rearrangement is a nice way to prepare secondary amines. This can be achieved by removal of oxygen via the use of $\ce{HI}$/$\ce{P}$. However, if ketones are used, ...
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71 views

Molecule analog similar and commercially available

I wanted to carry out some experiments on the following molecule: Unfortunately this molecule (santalene; either isomer will do) seems neither commercially available nor easily synthesizable. Hence ...
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122 views

Benzyl (3,4-difluorophenyl)carbamate reaction with epoxide in basic conditions

I attempted this mechanism, however I am uncertain if I am correct.

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