Comment by Chakravarthy Kalyan on Number of sterioisomers of...
I wrote only those that are optically active and have omitted meso and duplicates in my answer. However , I am well aware of these.I corrected my mistake.
View ArticleComment by Chakravarthy Kalyan on Why does phenolphthalein form in this...
from 4 to 5 , Cl para to hydroxyl group is undergoing nucleophillic aromatic substitution. Aryl halides are known to undergo nucleophillic aromatic substitution if nitro group is at ortho or para...
View ArticleComment by Chakravarthy Kalyan on Counting number of acidic-H in a molecule
@Rahul verma if two keto groups are in two 6 membred rings seperated by a carbon bonded to these two rings , the two keto groups may not be in the same plane.
View ArticleComment by Chakravarthy Kalyan on How to compare the rate of decarboxylation?
Compound 1 undergoes decarboxylation via vinologous intermediate. The intermediate is a vinyl alcohol. Not a carbanion. The comparision is akin to bananas and apples.
View ArticleComment by Chakravarthy Kalyan on Is a Methoxy group meta directing in this...
@Waylander , understood that Methoxy group activates ring. But electrophillic attack at meta gives an intermediate that is relatively unstable. Since intermediate is unstable , can EAS occur ?
View ArticleComment by Chakravarthy Kalyan on Why are two three-membered rings preferred...
Three membred ring is formed faster due to proximity effect.
View ArticleComment by Chakravarthy Kalyan on Is azonine planar?
Please check the following link en.m.wikipedia.org/wiki/Azonine . It clearly states , this molecule is planar.
View ArticleComment by Chakravarthy Kalyan on Disubstituted cyclic alcohols - looking for...
Sad to see loong's work not acknowledged.
View ArticleComment by Chakravarthy Kalyan on Dehydration reaction of an alcohol,...
Agree with @orthocresol .Further , what is the book & author ?
View ArticleComment by Chakravarthy Kalyan on Acidification of a vicinal diol
Steo 1 should be cyclopropane ring collapse, after protonation to give alkene and ketone. Step 2: Protonation of alkene keading to stable tertiary carbocation. Step 3 : carbocation as electrophile...
View ArticleComment by Chakravarthy Kalyan on Internal Electrophilic Aromatic Reaction in...
@shukraditya bose , reaction scheme and page number with edition eoukd help in answering. And circumastance of reaction can be understood.
View ArticleComment by Chakravarthy Kalyan on Will...
I realize now that configuration at 3rd carbon will not change. While tautomerism can occur between 1st a d 2nd carbon. Good work guys, thankyou.
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Answer by Chakravarthy Kalyan for Redox reactions redefined
As per IUPAC gold book , reduction and oxidation are defined as follows$^1$$^2$. A reduced species can be formed also through the gain of electrons (either at the negative electrode in a cell or...
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Answer by Chakravarthy Kalyan for What is non-hückel double bond of Aromaticity?
In the given molecule Pyrene , the π bond shown in green is in cross conjugation (shown in green in figure 1). This bond( figure 2) is excluded from interaction with rest of conjugated system. Hence ,...
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Answer by Chakravarthy Kalyan for Number of optically active compounds among...
Ozonolysis of the given compound gives $\ce{I}$ , $\ce{II}$ , $\ce{III}$ and $\ce{IV}$.$\ce{I}$ and $\ce{II}$ are Homomers and have same configuration "S" and therefore identical (as shown in the...
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Answer by Chakravarthy Kalyan for Radical monobromination of cycloalkane
The radical monobromination of bicyclo[2.2.1] heptane could give $\ce{1}$ ,$\ce{2}$ and $\ce{3}$.However , $\ce{2}$ and $\ce{3}$ , are unstable .On observing $\ce{2}$ , planar radical at bridgehead is...
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What is the major product obtained on acidification of substituted epoxide?
The problemSource : MS Couhan (problems in organic chemistry . Chapter: Alcohols , phenols and ethers).My ThoughtsIf I proceed along $\ce{path 1}$ , $\ce1a$ is formed . It is unstable due to inductive...
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Answer by Chakravarthy Kalyan for Which of the Following is Optically Active?
I am quoting from IUPAC GOLD book$^1$ .Meso-compound : A term for the achiral member(s) of a set of diastereoisomers which also includes one or more chiral members. For example:There is a plane of...
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Answer by Chakravarthy Kalyan for Which is more basic: 1,2‐dihydropyridine or...
In compound $\ce{A}$ , lone pair on $\ce{N}$ is in conjugation with two $\ce pi$ bonds (as shown below). Therefore this lone pair is delocalized (resonance structures in the figure below) to a greater...
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Answer by Chakravarthy Kalyan for Why does the tautomerism of purine favor...
The given purine has two structures as shown below.In $\ce{9H–Purine}$ (figure 2), lone pairs are far apart from each other (3 and 7). Comparatively in $\ce{7H–Purine}$ (figure 1) lone pairs are very...
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Answer by Chakravarthy Kalyan for Resonance and mesomeric effect
The relevant resonance structures of the given molecule are as follows.Structure A is shown below. NItrogen with 2 sigma bonds is linear as shown below. However , nitrogen in the ring is strained with...
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Answer by Chakravarthy Kalyan for Number of sterioisomers of...
The given compound 2,3,5,6-tetrachloroheptane has 10 isomers. These have been shown below.The compound 2,3,5,6-tetrachlorooctane in the link does not have a meso compound. The terminal groups, methyl...
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Answer by Chakravarthy Kalyan for Acidic cleavage of ether with a 2° alkyl group
what happens if a ether with a 2° alkyl group and a 1° alkyl group is cleaved with a halogen acid?To this question I have drawn a scheme below. The given ether is $\ce{2^0}$ group to the left and...
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Answer by Chakravarthy Kalyan for Which has the highest enol content?
The extent of enol content can be explained on the basis of acidic hydrogen, intramolecular hydrogen bonding.The stability of the carbanion formed is dependent on its stability after it is formed. In...
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Answer by Chakravarthy Kalyan for Are all lone pairs considered as π-electrons?
I am quoting from http://www.hutters-online.de/publikationen/dmchdo.html.One requirement that is basic to this concept and is agreed upon by most authors is that there have to be two double bonds that...
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What is proximity effect?
From Klein's Organic chemistry [1, p. 780]:The 1,2-adduct is believed to form more rapidly as a result of a proximity effect. Specifically, the carbocation and the bromide ion are initially very close...
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Will phosphorous Ylide participate in carbene generation and insertion?
The following question was sent to me . The answer for this question was given to me as option bI attempted it as following , recognizing the first step as a ylide reaction with a carbonyl compound.In...
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Answer by Chakravarthy Kalyan for Odd looking carbocation stability order
If hetro atom with lone pair is neighboring to carbocation, then that lone pair can be donated to empty orbital on carbocation (see figure below). These orbitals are said to be in conjugation....
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Answer by Chakravarthy Kalyan for SN2 reactions and inversion of...
Here I have a compound with 2 chiral centers. There is only inversion at Carbon with iodine undergoing $\mathrm{S_N2}$ reaction. The second carbon does not undergo $\mathrm{S_N}$ reaction. There is no...
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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 asIn Advanced Organic Chemistry, Part B: Reactions and...
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Answer by Chakravarthy Kalyan for Reaction mechanism of rearrangement
The first step is nucleophilic substitution.It is possible for nucleophile to attack directly at the allylic position, displacing the leaving group in a single step, in a process referred to as...
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Answer by Chakravarthy Kalyan for Which is the most acidic hydrogen in vitamin C
Compare the $\ce{OH}$ bonds in Vitamin C (ascorbic acid) and decide which one is the most acidic. The most acidic proton in ascorbic acid is the one whose conjugate base is most resonance...
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Which functional group gets reduced first?
The following is a reduction reaction. In the reduction of 2 to 3, keto group undergoes reduction by nucleophillic addition.Ester could undergo nucleophillic acyl substitution to give an aldo group,...
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Which of the canonical structures contributes more to resonance hybrid?
I am quoting a rule on resonance from Organic Chemistry by T.W. Graham Solomons, Craig B. Fryhle, 12th edition, page 25.Structures in which all the atoms have a complete valence shell of electrons...
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Answer by Chakravarthy Kalyan for What Are Examples of Reducing Sugar in...
Quoting from medium.comIf it wasn’t for Maillard, we would not have juicy seared steak, deep fried chicken wings, nor grilled sausages. All these browning, aromas and flavor bursts are a result of...
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Answer by Chakravarthy Kalyan for What atom would be protonated first in a...
In the given moleculeD's lone pair on oxygen is in conjugation with C=O group. Consequently it acquires a positive charge, its Kb is less for protonation to take place (as shown in scheme 1, as pointed...
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Will ferrocene undergo electrophilic aromatic substitution?
Ferrocene has two structures (1 and 2). It is bonded to the aromatic cyclopentadienyl anion. Aromatic species such as benzene, cyclopentadienyl anion undergo electrophilic aromatic substitutions.Then,...
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Answer by Chakravarthy Kalyan for Nucleophilicity in polar aprotic solvent...
let me start with nucleophilicity of halides. In protic polar solvent, $\ce{F^-}$ is more solvated (hydrogen bonding) than $\ce{I^-}$ and hence less reactive.In polar aprotic solvent$\ce{F^-}$...
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Why is porphyrin aromatic?
I was asked which of the following were aromatic:My understanding of aromatic nature is, that the molecule must be cyclic, planar, every atom in the ring must be $sp^2$-hybridized and the molecule must...
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