Carbanion || Reactive intermediates || Aldol condensation || Favorskii rearrangement
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- Опубликовано: 5 окт 2024
- #carbanion #organicchemistry #reaction
Quiz
1. Why carbanion has negative charge?
2. Why shape of carbanion is pyramidal and not tetrahedral?
3. Why trifluoro carbanion is more stable than tri methyl carbanion?
4. Define favorskii rearrangement reaction?
5. Write down names of methods of generation of carbanion?
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1- A carbanion has a Lone pair other than it's usuall valance electrons means it is electron efficient that's why it has a negative charge.
2- Although carbanions are sp³ hybridized (that should be a tetrahedral) , but they posses a pyramidal shape because of the bond angle , which is lesses than the regular tetrahedral bond angle.
3- triflouro carbanion is more stable than the trimethyl carbanion because triflouro has 3 flourine means it is more electro negative. More electronegative the molecule , more is the stablity.
4- The rearrangement of cyclopropane and alpha halo alkanes in the presence of base to carboxylic acid derivatives is known as favorskii rearrangement.
5- proton abstraction
Decarboxylation
Addition of nucleophile to alkene
Formation of organomettalic compound.
1: Because of heterocyclic cleavage
2: bond angle in carbanion are much less than regular terahedral angle of 109 28 that why carboanion donot have tetrahedral geometry but have pyramidal structure.
3:triflurocarbonium has more electronegative Atom than methyl carbonium
4: the rearragement of cyclopanone and alpha-halo ketone in the presense of base to carboxylic acid
5:
1/ proton abstraction
2/ decarboxylation
3/ addition of nuleophile to Alkene
4/ fornation of organo metallic compounds
1.
When covalent bond in which carbon is linked to less E.N atom/group is break up by cleavage the carbon atom takes away both bonding electrons and thus,aquire -ve charge.
2.
Carbanion is pyramidal b/c it has bond angle between 97° to 100°.
3.B/c TFM carbanion is more -ve than other and more stabilizing.
4.
The rearrangment of cyclopropane and alpha halo ketone in the presence of base to carboxylic acid derivative is known as Favoroskii rearrangment.
5.
Carbanion is generated by diffrent methods:
•Proton abstraction
•Decarboxylation
•Addition of nucleophile to alkene
•Formation of organometallic compounds.
1. a carbanion (ie, carbon
atom has a negative charge) In these species, a carbon atom carrying a negative charge has eight electrons in the valence shell-six from three covalent bonds and two from lone pair of electrons.
2. Since the lone pair-bond pair repulsions are expected to be greater than bond-pair bond-pair repulsions. The bond angles in
carbanions are much less than regular tetrahedral angle
of 109.28°.In other words, carbon ions do not have regular
tetrahedral geometry but have pyramidal structures in which bond angles are between 97°-100°
3.The energy barrier is different for different types of carbanions. For example for a
methyl carbanion the energy barrier is 2 kcal/mol, while for trifluoromethyl carbanion value is around 120 kcal/mol. The higher energy barrier of
trifluoromethyl carbanion is due to the mare electronegativity of a fluorine atom which is more stabilizing than a hydrogen atom.
4. Favoraskii rearrangement: The rearrangement of cyclopropanes and a-halo ketones in the presence of a base to
carboxylic acid derivatives are known as Favorskii
5. Some of the methods for the generation of carbanion are:
a.Proton abstraction
b.Decarboxylation
c.Addition of a nucleophile to an alkene
1) carbonation has negative charge b/c when there is covalent bond and carbon is attached with less electronegative atom Bond breaks by cleavage electron move towards more electronegative ,
2) shape of carbonion is pyrimidal
b/c hybridization is sp3 or geometry angle b/w is 97 to 100 ,
3) Trifluro carbanion are more stable than methyl carbanion due to more electronegative atom of flourine ,
4)The rearrangement of cyclopropane and -a hola ketone is the presence of base to carboxylic acid derivative is knoias favorski arrangements,
5) proton abstraction
Decarboxylation addition of nucleophile to alkene formation of organomettalic compound,
Q1) Carbanion has negative charge because when their is covalent bond and carbon is attached with less electronegative atom bond breaks by cleavage, electrons move towards more electronegative(C) .
Q2) Shape of Carbanion is pyramidal while it has sp3 hybridization because lone pair-bond pair repulsion is greater than bond pair-bond pair repulsion and its bond angle is less than tetrahedral.
Q3) Trifluoro carbanion is more stable than methyl carbanion due to more electronegativity of fluorine.
Q4) The rearrangement of cyclopropanones and alpha-halo ketones in presence of base to carboxylic acid derivates is called Favorski rearrangment.
Q5)
1-Proton abstract
2-Decarboxylation
3-Addition of nucleophile to alkene
4-Formation of organometallic compounds.
Qno:1 A carbanion can be defined as a negatively charged ion in which a carbon atom exhibits trivalence (implying it forms a total of three bonds) and holds a formal negative charge whose magnitude is at least -1
Qno:2 carbanion is sp3 hybridised with one lone pair of electron pyramidal in shape.
Qno:3 trifluoro carbanion is more stable then tri methyal carbanion b/c of the presence of three EWG
Qno:4 the rearrangements of cyclopropanones and alpa halo ketones in the presence of base to carboxylic acids derivatives known as favorskii rearrangement
Qno: 5. Proton abstraction
Decarboxylation
Additiona of nucleophilic to alkenes
Q:1 Carbonation has negative charge bcz when there is covalent bond and carbon is attached with less electronegative atom bond breaks by cleavage electron move towards more electronegative (c) .
Q:2 shape of Carbanian is pyramidal while it has sp3 hybridization bcz lone pair -bond pair repulsion is greater than bond pair -bond repulsion and its bond angle is less than tetrahedral.
Q:3 Trifluro carbonian is more stable than methyl carbonian due to more electronegativity of fluorine
Q:4 The rearrangement of cyclopropanones and alpha -halo ketones in presence of base to carboxylic acid derivatives is called Favorski rearrangement .
Q5: 1 Proton abstract
2 Decarboxylation
3 addition of nucleophile to Alkene
4 Formation of organometallic conpounds
QUESTION :1
a carbanion (ie, carbon
atom having negative charge) In these species, carbon atom carrying negative charge has eight electrons in the valence shell-six from three covalent bonds and two from lone pair of electrons.
Question:2
Since the lone pair-bond pair repulsions are expected to be greater than bond-pair bond-pair repulsions. The bond angles in
carbanions are much less than regular tetrahedral angle
of 109.28°.In other words, carbonions do not have regular
tetrahedral geometry bat have pyramidal structure in which bond
angles are in between 97°-100°
Question:3
The energy barrier is different for different types of carbanions. For example for a
methylcarbanion the energy barrier is 2 kcal/mol, while for trifluoromethyl carbanion value is around 120 kcal/mol. The higher energy barrier of
trifluoromethyl carbanion is due to the mare electronegativity of floorine atom which is more stabilizing than a hydrogen atom.
Question:4
Favoraskii rearrangement: The rearrangement of cyclopropanones and a-halo ketones inthe presence of base to
carboxylic acid derivatives is known as Favorskii
QUESTION:5
Some of the methods forthe generation of carbanion are:
°Proton abstraction
°Decarboxylation
°Addition of nucleophile to alkene.
Q1.when covalent bond in which carbon is linked to less electronegative atom or group is break up by cleavage the carbon atom takes away boty bonding electron and thus aquire negative charge.
Q2. Shape of caboanion is pyramidal because hybirdization is sp³ or geometry angle between is 97⁰ to 100⁰.
Q3. Trifluro carboanion is more stable than the tri methyl carboanion because of three of electro withdrawimg group.
Q4. The rearrangement of cyclopropanones and a-halo ketone is the presence of base to carboxylic acid derivatives is known as favorski arrangement.
Q5. Proton abstraction
Decarboxylation
Addition of nucleophillic alkenes
Ans 1
When covelent bond in which carbon is linked to less electronegative atom group is break up by cleavage the atom takes away both bonding electrons and thus aquire negative charge.
Ans 2
Shape of Carbonanion is pyrimidal because of hydrization sp3 or geometry (angle in between 97°-100°)
Ans 3
Triflouro carbonion is more stable then trimethyl carbonion because of the presence of three EWG
Ans 4
The rearrangement of cyclopropanones and a-halo ketones in the presence of base of carboxylic acid derivative is known as favourskii rearrangement
Ans 5
Proton abstraction
Decarboxy cation
Addition of Nucleophile to alkenes
Q1 The carbanion is negative due to the 8electron in valence electron
Q2 the shape of carbanion is pyramidal due the lone pair repulsion and bond angle is much less then the tetrahedral
Q3 rearangemnts of cyclopropane and heloketone in presence of the base and carboxylic acid to derivates
Q4
Protone abstruction
Addition of nucloephile and alkene
Formation of organometallic compound
Bakhtawar aijaz
Q1 carbanion( carbon atom carrying negative charge )in this species carbon atom carrying negative charge has eight electron in their valence shell six from three covalent bond and 2 from lone pair of electron.
Q2 carbanion have a pyramidal structure but not tetra hyderal because of bond angle which is about between 97° to 100°.
Q3 the energy barrier is different for different types of carbanion. For example a methylcarbanion has 2 kcal/mol while for trifluromethyl carbanion value is around 120kcal/mol . The higher energy barrier of trifluromethyl carbanion is due to the more electronegative of flourine atom which is more stablize than hydrogen atom.
Q4 the rearrangement of cyclopropanone and alpha halo ketones in the presence of base and carboxylic acid.
Q5 proton abstruction
Decarboxylation
Addition of nucleophile to alkene
Dr try again ur Q #01 and 03 other answers are ok.
@@farazqurbanrajper5074 okay sir
Q#1 carboanion has negative charge because it is electron rich species and have lone pair of electron
Q#2 carboanion is pyramidal because it has bond angle 97-100
Q#3 Because trifloromethyl carboanion is more negative than other and more stabilizing
Q#4 The rearrangement of cyclopropane and alpha halo ketone in the presence of base to carboxylic acid derivatives is known as favoroski rearrangement.
Q#5 carboanion is generated by different methods
1 proton abstraction
2decarboxylation
3 addition of nucleophile to alkene
4 formation and organometallic compound
Question no:1
Carbanion has the negative charge because the electron rich species due to lone pair of electron.
Question no:2
Lone pair bond pair replusion are greater extend bond pair bond pair replusion bond angle of carbanion do not have regular tetrahedral 109.28° but have carbanion pyramidal shape 97°-100
Question no:3
Trifluro carbanion are more stable than methyl carbanion due to more electronegative atom of flourine.
Question no:4
The favorskii rearrangement is the cylcopropanone and Alpha halo ketone in the presence of base to give carboxylic acids derivative.
Question no:5
1. Proton abstraction
2. Decarboxylation
3. Addition of nucleophile to alkene
4.foramtion of organometallic compounds
Question No:01
Ans: Carbanion has negative charge because it is electron rich species and have extra lone pair of electrons
Question No:02
Ans: Carbanion is pyramidal in shape because The bond angles in carbanions are much less than tetrahedral angle of 109.28°. it has bond angle between 97-100° and has Sp³ hybridization .
Question No:03
Ans: The higher energy barrier of triflouromethyle carbonian is due to the mare electronegativity of fluorine atom which is more stabling than a hydrogen atom.
Question No:04
Ans: The rearrangement of cyclopropanones and alpha halo ketone in the presence of base to carboxylic acid derivative is known as Favorski rearrangement
Question No:05
Ans: some of the methods for the generation of carbanion are:
1) Proton abstraction
2) Decarboxylation
3) Addition of nucleophile to alkene
Q1 The carbanion is negative due to the 8 electron in valence electron
Q2 The shape of carbanion is pyramidal due the lone pair repulsion and bond angle is much less then tetrahedral
Q3 Triflouro is more stable then the due the negativity of electron in a atom more then hydrogen
Q4 Rearrangement of cyclopropane and haloketone in the presence of the base and carboxylic acid to dervitives
Q5
Proton abstruction
Decarboxylation
Addition of nucleophile to alkene
Formation of organometallic compound
Q1: carbanion has negative charge because it is electron rich species and have lone pair of electron.
Q2: carbanion is pyramidal because it has bond angle 97- 100°.
Q 3 ; Because trifloromethyl carbanion is more electronegative than other and more stabilizing .
Q4: The rearrangment of cyclopropanones and alpha halo ketone in tha presence of base to carboxylic acid derivative is known as favorski rearrangement.
Q5: carbanion is generated by different methods
1 proton abstraction
2 decarboxylation
3 addition of nucleophile to alkene
4 formation of organometallic compounds.
QUESTION :1
ANSWER:
a carbanion (ie, carbon
atom having negative charge) In these species, carbon atom carrying negative charge has eight electrons in the valence shell-six from three covalent bonds and two from lone pair of electrons.
Q:2
ANSWER:2
Since the lone pair-bond pair repulsions are expected to be greater than bond-pair bond-pair repulsions. The bond angles in
carbanions are much less than regular tetrahedral angle
of 109.28°.In other words, carbonions do not have regular
tetrahedral geometry bat have pyramidal structure in which bond
angles are in between 97°-100°
Q:3
ANSWER:
The energy barrier is different for different types of carbanions. For example for a
methylcarbanion the energy barrier is 2 kcal/mol, while for trifluoromethyl carbanion value is around 120 kcal/mol. The higher energy barrier of
trifluoromethyl carbanion is due to the mare electronegativity of floorine atom which is more stabilizing than a hydrogen atom.
Q:4
ANSWER:4
Favoraskii rearrangement: The rearrangement of cyclopropanones and a-halo ketones inthe presence of base to
carboxylic acid derivatives is known as Favorskii
QUESTION:5
ANSWER 5
Some of the methods forthe generation of carbanion are:
°Proton abstraction
°Decarboxylation
°Addition of nucleophile to alkene
Q1 carbonian has -ve charge because it is electron rich specie and have lone pair of electrons
Q2 shape of carbonian is pyramidal and it’s bond angle is 97-100
Q3 trifluro carbonian is more stable than tri methyl carbonian because 3 electron with drawing group
Q5 proton abstraction, decarboxylation,addition of nucleophile to alkene
Qno:1
Ans: Carbanion has negative charge because it is electron rich species and have lone pair of electron
Qno:2
Ans: Carbanion is pyramidal because it has bond angle 97-100
Qno:3
Ans: Because trifloromethyl carbanion is more electronegative than other and more stabilizong.
Qno:4
Ans: The rearramgement of cyclopropanones and alpha halo ketone on the presence of base to carboxylic acid derivative is known as favoroski rearrangement
Qno:5
Ans: Carbanion is generated by different method
proton abstraction
decarboxylation
addition of nucleophile to alkene
formation or organometallic compound
Q1=The shared pair of electrons remains with one of the fragments.One atom has a sextet electronic structure and a positive charge and the other, a valance octet with atleast one lone pair and a negative charge.
Q2= Carbanion have a pyramidal structure ,not tetrahyderal because of bond angle which is between 97° to 100°.
Q3= The chlorine atoms have vacant d orbitals which the fluorine atoms don't. So, this allows effective back bonding and the negative charge on the C-atom is delocalised to a much greater extent
. The higher electron affinity and the lesser electronic repulsion allows the delocalisation of the negative to a greater extent in trichloromethyl carbanion.
So, greater the delocalisation of charge density, greater is the stability of the species. Hence, trichloromethyl carbanion is more stable than trifluoromethyl carbanion
.
Q4= The rearrangement of cyclopropanone and alpha halo ketones in the presence of base and carboxyl acid.
Q5= Proton abstraction
Decarboxylation
Addition of nucleophile to alkene.
Q1 & Q3 wrong. Try again these Q
Sir question no 3 ek br again dekh le
Answer#1 ► A carbanion is an ion with a negatively charged carbon atom. The most stable carbanions have six electrons in the valence shell of the carbon atom. Carbanions are important in organic chemistry because they can act as nucleophiles, which means they can donate electrons to other molecules. Carbanions are also important in biochemistry because they can be used to transfer electrons between molecules.
Answer#2 Carbanion is formed if one proton is removed from methane molecule. Therefore, the shape of carbanion is 'pyramidal'.
It is made up of one s-orbital and two p-orbitals in equal proportions. Carbocation possesses three sigma bonds, which results in a trigonal planar shape.
Answer#3 Triphenylmethyl cation is more stable than trimethylmethyl cation because the resonance
Answer#4
the rearrangement of cyclopropane and alpha halo ketone in the presence of base to carboxylic acid derivatives is known as favoroski rearrangement.
Answer #5
carboanion is generated by different methods 1 proton abstraction 2decarboxylation 3 addition of nucleophile to alkene 4 formation and organometallic compound
Q1
Ans: Carbanion Have negative charge because of electronegativity effect when carbon is covelentlty bonded with a atom which have less electronegativity than carbon it causes attraction effect of electrons toward more electronegative atom which is carbon in case of carbanion. Carbanion have 8 electrons in outer most shell 6 are paired and 2 are unpaired which also known as lone pair negative charge is due to this lone pair
Q2
....Ans: As we know the shape of molecules Is related with hybridization as carbanion have Sp3 hybridization 3 bonded pairs and one lone pair this result pyramidal shape and tetra hedral arrangements of electrons
Q3
Ans: Because of electronegativity effect the most stable carbanion is one in which carbon is bonded with most electronegative atom this increase the dislocation of bonds and inductive effect also due to dislocation of bonds more resonance structures are forms
Ans: rearrangement of cyclopropanones and α-halo ketones that leads to carboxylic acid derivatives.
When enolate formation is impossible, the Favorskii rearrangement takes place by an alternate mechanism, in which addition to hydroxide to the ketone takes place, followed by concerted collapse of the tetrahedral intermediate and migration of the neighboring carbon with displacement of the halide.
Q5
Ans : Carbanion are generated by the attack of nucleophiles on one of the carbon of an alkene. It results into the development of negative charge on the other carbon atom
Aneesa 08
A=
a carbanion In these species, carbon atom carrying negative charge has eight electrons in the valence shell-six from three covalent bonds and two from lone pair of electrons. So it has a negative charge on it due to efficiency oe electrons
A=
Since the lone pair-bond pair repulsions are expected to be greater than bond-pair bond-pair repulsions. The bond angles in
carbanions are much less than regular tetrahedral angle
of 109.28°.In other words, carbonions do not have regular
tetrahedral geometry bat have pyramidal structure in which bond
angles are in between 97°-100°
A=
The energy barrier is different for different types of carbanions. For example for a
methylcarbanion the energy barrier is 2 kcal/mol, while for trifluoromethyl carbanion value is around 120 kcal/mol. The higher energy barrier of
trifluoromethyl carbanion is due to the mare electronegativity of floorine atom which is more stabilizing than a hydrogen atom.
A=
Favoraskii rearrangement: The rearrangement of cyclopropanones and a-halo ketones inthe presence of base to
carboxylic acid derivatives is known as Favorskii
A=
Some of the methods forthe generation of carbanion are:
°Proton abstraction
°Decarboxylation
°Addition of nucleophile to alkene
Q#1
When covalent bond in which carbon is linked to less electronegative atom/group is break up by cleavage the carbon atom takes away both bonding electrons and thus aquire negative charge
Q#2
Shape of carbanion is pyramidal because of hybridization (sp³ ) or geometry ( angle in between 97° -- 100°)
Q#3
Triflouro carbanion is more stable than tri methyl carbanion because of the presence of three EWG
Q#4
The rearrangement of cyclopropanones and a- halo ketones in the presence of base to carboxylic acid derivatives is known as favorskii rearrangement.
Q#5
Proton abstraction
Decarboxylation
Addition of nucleophillic to alkenes.
Ans 1: when covalent bond in which carbon is linked to less electronegative atom is break up by cleavage the carbon atom takes away bonding electrons thus carbon has negative charge. Ans 2: shape of carbanion is pyramidal because of SP3 hybridization . Ans 3: trifluoro carbanion is more stable than tri methyl carbanion is because of three electron withdrawing group. Ans 4: The rearrangement of cyclopropanones and a halo ketones is the presence of base to carboxylic acid derivatives known as favorskii rearrangement. Ans 5: proton abstraction , Decarboxylation, addition of nucleophiles to alkenes .
1: a carbanion (ie, carbon
atom having negative charge) In these species, carbon atom carrying negative charge has eight electrons in the valence shell-six from three covalent bonds and two from lone pair of electrons.
2: Since the lone pair-bond pair repulsions are expected to be greater than bond-pair bond-pair repulsions. The bond angles in
carbanions are much less than regular tetrahedral angle
of 109.28°.In other words, carbonions do not have regular
tetrahedral geometry bat have pyramidal structure in which bond
angles are in between 97°-100°
3: The energy barrier is different for different types of carbanions. For example for a
methylcarbanion the energy barrier is 2 kcal/mol, while for trifluoromethyl carbanion value is around 120 kcal/mol. The higher energy barrier of
trifluoromethyl carbanion is due to the mare electronegativity of floorine atom which is more stabilizing than a hydrogen atom.
4:Favoraskii rearrangement: The rearrangement of cyclopropanones and a-halo ketones inthe presence of base to
carboxylic acid derivatives is known as Favorskii
5: Some of the methods forthe generation of carbanion are:
°Proton abstraction
°Decarboxylation
°Addition of nucleophile to alkene
Q1.when covalent bond in which carbon is linked to less electronegative atom or group is break up by cleavage the carbon atom takes away boty bonding electron and thus aquire negative charge.
Q2. Shape of caboanion is pyramidal because hybirdization is sp³ or geometry angle between is 97⁰ to 100⁰.
Q3. Trifluro carboanion is more stable than the tri methyl carboanion because of three of electro withdrawimg group.
Q4. The rearrangement of cyclopropanones and a-halo ketone is the presence of base to carboxylic acid derivatives is known as favorski arrangement.
Q5. Proton abstraction
Decarboxylation
Addition of nucleophillic alkenes
Q1 The carbanion is negative due to the 8electron in valence electron
Q2 the shape of carbanion is pyramidal due the lone pair repulsion and bond angle is much less then the tetrahedral
Q3 rearangemnts of cyclopropane and heloketone in presence of the base and carboxylic acid to derivates
Q4
Protone abstruction
Addition of nucloephile and alkene
Formation of organometallic compound
Aqsa Memon
QUESTION :1
ANSWER:
a carbanion (ie, carbon
atom having negative charge) In these species, carbon atom carrying negative charge has eight electrons in the valence shell-six from three covalent bonds and two from lone pair of electrons.
Q:2
ANSWER:2
Since the lone pair-bond pair repulsions are expected to be greater than bond-pair bond-pair repulsions. The bond angles in
carbanions are much less than regular tetrahedral angle
of 109.28°.In other words, carbonions do not have regular
tetrahedral geometry bat have pyramidal structure in which bond
angles are in between 97°-100°
Q:3
ANSWER:
The energy barrier is different for different types of carbanions. For example for a
methylcarbanion the energy barrier is 2 kcal/mol, while for trifluoromethyl carbanion value is around 120 kcal/mol. The higher energy barrier of
trifluoromethyl carbanion is due to the mare electronegativity of floorine atom which is more stabilizing than a hydrogen atom.
Q:4
ANSWER:4
Favoraskii rearrangement: The rearrangement of cyclopropanones and a-halo ketones inthe presence of base to
carboxylic acid derivatives is known as Favorskii
QUESTION:5
ANSWER 5
Some of the methods forthe generation of carbanion are:
°Proton abstraction
°Decarboxylation
°Addition of nucleophile to alkene
Q1.when covalent bond in which carbon is linked to less electronegative atom or group is break up by cleavage the carbon atom takes away boty bonding electron and thus aquire negative charge.
Q2. Shape of caboanion is pyramidal because hybirdization is sp³ or geometry angle between is 97⁰ to 100⁰.
Q3. Trifluro carboanion is more stable than the tri methyl carboanion because of three of electro withdrawimg group.
Q4. The rearrangement of cyclopropanones and a-halo ketone is the presence of base to carboxylic acid derivatives is known as favorski arrangement.
Q5. Proton abstraction
Decarboxylation
Addition of nucleophillic alkenes
Ans 1 When covalent bond in which carbon is linked to less electronegative atom or group is break up by cleavage the carbon atom takes away boty bonding electrons and thus acquire negative charge. Ans 2 Shape of carbon is pyramidal because hybridization is sp3 or geometry angle b/w is 97° to 100° Ans 3 Trifluro carboanion is more stable than the tri methyl carboanion because of three of electrons withdrawing group. Ans 4 The rearrangement of cyclopropane and -a halo ketone is the presence of base to carboxylic acid derivative is knoias favorski arrangements. Ans 5 Proton abstraction ,. Decarboxylation , Addition of nucleophilic alkene.
QUESTION :1
ANSWER:
a carbanion (ie, carbon
atom having negative charge) In these species, carbon atom carrying negative charge has eight electrons in the valence shell-six from three covalent bonds and two from lone pair of electrons.
Q:2
ANSWER:2
Since the lone pair-bond pair repulsions are expected to be greater than bond-pair bond-pair repulsions. The bond angles in
carbanions are much less than regular tetrahedral angle
of 109.28°.In other words, carbonions do not have regular
tetrahedral geometry bat have pyramidal structure in which bond
angles are in between 97°-100°
Q:3
ANSWER:
The energy barrier is different for different types of carbanions. For example for a
methylcarbanion the energy barrier is 2 kcal/mol, while for trifluoromethyl carbanion value is around 120 kcal/mol. The higher energy barrier of
trifluoromethyl carbanion is due to the mare electronegativity of floorine atom which is more stabilizing than a hydrogen atom.
Q:4
ANSWER:4
Favoraskii rearrangement: The rearrangement of cyclopropanones and a-halo ketones inthe presence of base to
carboxylic acid derivatives is known as Favorskii
QUESTION:5
ANSWER 5
Some of the methods forthe generation of carbanion are:
°Proton abstraction
°Decarboxylation
°Addition of nucleophile to alkene