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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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Stability of the alkenyl and phenyl cations

One reason often cited for why alkenyl and phenyl halides do not undergo nucleophilic substitution by the $\ce {S_N1}$ mechanism is that the formation of the alkenyl and phenyl cations involve a ...
0
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1answer
72 views

Basic strength of nitrogen

What is the order of basic strength of nitrogens in the compound given in the figure? $$\ce{ H2\overset{.\!\!.}{\underset{(γ)}{N}}-\overset{.\!\!.}{\underset{(β)}{N}}H-\overset{\overset{\huge O}{||}}{...
2
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1answer
42 views

Thermodynamics behind organic chemical reactions? [closed]

I took organic chemistry a few years ago at my university, and although I went through the motions to pass the exams, I didn't understand the thermodynamic reasoning behind why the reactions actually ...
8
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0answers
58 views

How is the aromaticity in graphene different from the aromaticity in benzene?

The web page Aromaticity in Graphene and other 2-D Systems begins: I. Graphene While the σ-bonding in graphene is assumed to be a rigid honeycomb framework built out of two-center two-...
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1answer
66 views

Why does Azo coupling of β-naphthol takes place at alpha position and not at gamma position [duplicate]

I have searched for coupling reaction of $\beta$-naphthol with benzene diazonium salt at quite a few places. But everywhere the coupling has been shown at alpha position. Why doesn't it take place at ...
1
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0answers
70 views

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 ...
0
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1answer
32 views

Organic reaction rate equations needed [closed]

Where to find a list of common organic reaction rate laws?? Anybody has this?? I could not find one on internet
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0answers
54 views

Do alkenes have priority over alkynes in R/S naming?

I am studying for an upcoming exam and I came upon a confusing question for the drawing of the molecule (3⁠R)-hex-1-en-5-yn-3-ol. Why is the stereocenter (3-carbon) R? Shouldn't it be S? After ...
4
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1answer
55 views

Why do we use LiCl as a source of chloride ions as nucleophile but not other alkali metal chlorides? [closed]

$\ce{LiCl}$ has higher covalent character than other alkali-metal chlorides, so in polar solutions like ethanol, its ioniztion will be less, and so less chloride ions will be available for ...
12
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1answer
162 views

What is the physical origin of conjugation?

I had a question about the origins of conjugation in conjugated molecules. Take two ethylenes as compared to butadiene. Huckel seemed to argue that conjugation was the result of pi-pi stabilization ...
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0answers
20 views

Confusion Regarding Nitrogen Inversion

In nitrogen inversion, the lone pair changes its direction continuously. Does this in any way delocalize the charge density on the nitrogen making it less nucleophilic and less basic than another ...
3
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1answer
54 views

What will be the major enol form of methyl acetoacetate?

I presume the best enol form would have a double bond between the two $\ce{C=O}$ so they're conjugated, but I'm not sure how the resonance would play out.
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What could cause foam formation in a Wet Flue Gas Treatment process ? (Desulfurization)

The process in question is a Desulfurization process operating in Close Loop mode. It means that the initial seawater is recirculated a given number of time in the process. In the mean time, a small ...
2
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1answer
60 views

Why is adenine aromatic?

I don't think it follows the $4n + 2$ rule. The double bonds give 8 π electrons. Then the lone pairs on the $\ce{NH}$ and $\ce{NH2}$ groups are delocalized (are they?) so they must contribute 4 π ...
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0answers
41 views

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 ...
8
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0answers
118 views

What is the mechanism for this reaction?

The closest reaction I can find is Lossen rearrangement but in that hydroxyamic acid is first converted to its derivative but how will that be possible here? Moreover, even if I make an amine in this ...
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1answer
114 views

Why do weak acids like ethanol not act as a strong base in water?

In water, ethanol has a $\mathrm{p}K_\mathrm{a} = 15.9$ which means that its $\mathrm{p}K_\mathrm{b}$ is $-1.9$. Which implies that all weak acids in water are in fact strong bases. But this is not ...
1
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1answer
76 views

What will be the order of acidity in the following compounds? [closed]

What will be the order of acidity in the following compounds ? From My point of view it should be 3>1>2>4. But the answer given is 3>2>1>4. Can anyone explain how ?
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1answer
39 views

Why is 5-chloro-1-methylcyclopentene not named 3-chloro-2-methylcyclopentene? [duplicate]

Why is the ring numbered the way it is? What is it about the double bond that makes it so? source
1
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1answer
46 views

When does ipso attack occur in electrophilic aromatic substitution?

My textbook doesn't mention the conditions required for an ipso attack to occur. It just describes some examples where groups like $\ce{-C(CH3)}$ and $\ce{-SO3H}$ are replaced by $\ce{Br}$ using ...
3
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1answer
24 views

Names of NAD+ and NADH

As part of the biochemical process of glycolysis, NAD+ is reduced to NADH. In other words, nicotinamide adenine dinucleotide is reduced to... nicotinamide adenine dinucleotide? Everywhere I look ...
3
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0answers
84 views

Synthesis of anthranilic acid

Yesterday, I performed the synthesis of anthranilic acid (also known as, 2-aminobenzoic acid. I was instructed to use the common route that is also featured on the Wikipedia page for this compound. ...
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1answer
25 views

What is the chemical equation for the digestion/decomposition of cellulose?

I'm trying to find the chemical equation/pathway from cellulose $\ce{(C6H10O5)_n}$ to methane $\ce{CH4}$. What are the other reactants or products in the reaction? $$\ce{C6H10O5 + ? -> CH4 + ?}$$ ...
4
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0answers
49 views

Reagents for synthesis of ethyl 2-(2,3-dihydrobenzofuran-2-yl)acetate from naphthalen-1(4H)-one

The following conversion can be performed in a few steps. Show key intermediates and reagents (detailed mechanisms are not required). So I've been looking at this for a while and I can't seem ...
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2answers
68 views

reaction mechanisms of peroxides

Task: Explain the reaction mechanism of 1,4-Dioxane in terms of how you get peroxides. Start here with the autoxidation with one radical X. My explanation: in the first step 1,4 Dioxan reacts with ...
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0answers
24 views

H-bonding in o-hydroxybenzoic acid [duplicate]

Amongst all hydroxybenzoic acids the ortho isomer is most acidic and the major reason is intramolecular H-bonding in the anion. My question is that isn't the loss of proton destabilising the molecule ...
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0answers
56 views

Does acetophenone show haloform reaction?

Although acetophenone is a methyl ketone, as it is aromatic, it is immiscible in H2O so the last step in the haloform reaction should not occur? I couldn't find any source regarding the haloform ...
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0answers
19 views

Flow of electrons DNMT [closed]

In a paper about the modes of action of DNMT, it said there an increased flow of electrons to carbon 5 following the formation of a covalent bond between DNMT and carbon 6 on cystine. Why is this? ...
0
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1answer
50 views

Can I determine purity of isopropanol with a hydrometer?

Assuming I start with a known 99.8% purity of isopropanol, after recovery with a distillation apparatus, could I use a hydrometer to test for water content? If so, is there a special one I should use?
4
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1answer
131 views

Why do polar aprotic solvents favour SN2 over E2?

I was reading about Substitution and Elimination Reactions and I came across the following on MasterOrganicChemistry: Polar protic solvents tend to favor elimination (E2) over substitution (SN2). ...
4
votes
2answers
148 views

Chiral carbon in carvone molecules

This is the structure of carvone, with the chiral carbon noted by *. I don't understand why this is a chiral carbon, to my understanding a chiral carbon is a carbon with 4 different chemical groups ...
1
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1answer
47 views

Hydroxide as leaving group in Aldol Condensation in base [closed]

My professor said that in the base-catalyzed aldol condensation, because there is a lot of hydroxide already in solution, hydroxide on the beta position on a ketone can act as a leaving group. What's ...
3
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1answer
31 views

Why does Methyl Carbocation have p orbital

For a carbocation to form, it needs to lose an electron. In the example below the leaving group is Br and the products are a methyl carbocation and a bromide ion. What I am unsure about is why the ...
5
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2answers
141 views

LiOH hydrolysis of methyl 2,2-dimethoxyacetate not giving product?

I am forming 2,2-dimethoxyacetic acid from its methyl ester, and below is the experimental protocol I am following (from Tetrahedron 2016, 72 (3), 420–430): 2,2-Dimethoxy Acetic Acid Formation ...
0
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1answer
98 views

Dehydration of carboxylic acids with phosphoric acid

To find Z one must find X. Finding Y is of no use to find Z. I get X as: After addition of $\ce{H2/Pd-C}$, the unsaturated portion becomes saturated and the carboxylic acid remains unchanged. ...
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0answers
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Why is the fragrant molecule linalool volatile when it has hydorgen bonding?

I've done a bit of research on volatile molecules and from what I've read, highly volatile molecules should have weak intermolecular forces (easy to go from liquid to gaseous state)....however it ...
7
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0answers
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What is the hybridization state of the carbon atoms in [10]annulene?

I know that one of the more stable structures of [10]annulene or cyclodecapentaene is planar boat-shaped. But that means the hybridization state of the carbons must have changed to suit the geometry. ...
7
votes
1answer
420 views

Do quaternary sulfur dications exist?

We know that sulfur can form sulfides $\ce{R2S}$, with two substituents bonded to it. The simplest example of this would be hydrogen sulfide. However, sulfur can also form sulfonium ions $\ce{R3S+}$,...
4
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1answer
65 views

Stereochemical outcomes in opening of vinyl epoxides

Explain the outcomes of the following reactions. In each case the major product is shown. Firstly, I don't understand why the chloride always attacks on the right hand side of the epoxide. Also,...
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1answer
48 views

SN1, SN2 and enantiomeric excess

When (R)-2-bromobutane is heated with water, the $\mathrm{S_N1}$ substitution proceeds twice as fast as $\mathrm{S_N2}$. Calculate the appropriate enantiomeric excess and the specific rotation of the ...
7
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2answers
95 views

Are the triply-bonded carbons in pyridyne (and benzyne) sp-hybridised?

I was given this molecule (3,4-pyridyne) in a test: I had to find out if it had any atoms which had a hybridization state other than sp2. The solution said that it doesn't have any. But aren't the ...
3
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0answers
51 views

Can benzene undergo Diels–Alder reactions?

I was reading about the Diels–Alder reaction and wondered that since benzene also consists of two conjugated double bonds, then should it also undergo Diels–Alder reactions? If not, then why not?
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2answers
47 views

Which of the five main branches of chemistry has the most labwork? [closed]

Budding chemistry student here. I am aware of the so called "five branches" of chemistry, namely organic, inorganic, bio, physical and analytical. Which of these paths lead to work with the most ...
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0answers
22 views

Aromaticity of Tropone [duplicate]

When we are determining if a given compound is aromatic using Hückel's rule, we count the number of delocalized $\pi$ electrons. In tropone for example, if I wanted to count the number of delocalized ...
1
vote
1answer
60 views

The products of a chain reaction beginning with acetone and sodium amide

I encountered the following question in an exam: $\ce{CH3COCH3 + NaNH2}$  giving out $\ce{A}$. $\ce{A}$ then reacts with $\ce{C2H2}$ giving out $\ce{B}$. $\ce{B}$ then reacts with $\ce{H+}$ to ...
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1answer
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33 views

Organic conversion involving Grignard reagent and alkyl group with a carbonyl carbon on an benzene ring

I have been asked to synthesize the organic compound shown below using the following reagents and solvents. $\ce{Mg, Zn, Hg, FeBr3, AlCl3, Br2, LiAlH4, KMnO4}$, dil. $\ce{H2SO4}$, conc. $\ce{NH3}$, ...
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1answer
35 views

How to chelate magnesium oxide and l-lysine [closed]

Given magnesium oxide and l-lysine dissolved in water. What needs to happen so that both form a chelate inside the solution.
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0answers
28 views

Halogen bonding in organic reactions

Recently, a group of researchers from the Nanyang Technological University in Singapore have investigated the novel $\ce {S_N2X}$ mechanism which involves a "frontside attack" on the substrate, rather ...
0
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1answer
22 views

Do the mechanism (SN1 or SN2 ) which reaction follow depends more upon intermediate stability than on substrate and nucleophilic?

For eg : would the reaction of 3-methylbut-2-en-1-ol with HBr follow SN1 mechanism due to stability of your intermediate carbocation stability or SN2 due to the compound being primary alcohol and ...