aldehydes & ketones - مواقع اعضاء هيئة التدريس | ksu...

Aldehydes & Ketones

Chapter 6

Dr. Seham ALTERARY

Chem 340- 2nd semester 1437-1438

Chapter out lines Definition & General Structure Aldehydes.

Common Names for Aldehydes.

IUPAC Nomenclature of Aldehydes.

Physical Properties of Aldehydes and Ketones.

Preparation of Aldehydes and Ketones.

Definition & General Structure Ketones.

Common and IUPAC Naming of Ketones.

Reactions of Aldehydes and Ketones.

Chapter 6; Aldehydess& Ketoness


1) Aldehydes

The aldehyde group is always at the end of a chain, so it will

always take number 1.

General formula: RCHO or RCH=O

Aldehydes and ketones are simple compounds which contain a

carbonyl group - a carbon-oxygen double bond.

What are aldehydes and ketones?

In aldehydes, the carbonyl group has a hydrogen atom attached

to it together with either

- a second hydrogen atom

- or, more commonly, a hydrocarbon group which might be an alkyl

group or one containing a benzene ring.

C

O

HR



Common names for aldehydes are derived from the common names

of carboxylic acids. They often reflect the Latin or Greek term for

the original source of the acid or the aldehyde.

Common Names for Aldehydes A

cid

Ald

ehyd

e

Propionic acid Butyric acid Formic acid Acetic acid

Formaldehyde Acetaldehyde Propionaldehyde Butyraldehyde



Valeric acid

Valeraldehyde

http://en.wikipedia.org/wiki/File:Formaldehyde-2D.svg

http://en.wikipedia.org/wiki/File:Acetaldehyde-tall-2D-skeletal.png

http://en.wikipedia.org/wiki/File:Propanal-skeletal.png

http://en.wikipedia.org/wiki/File:Butanal-skeletal.png

http://en.wikipedia.org/wiki/File:Ameisens%C3%A4ure_Keilstrich.svg

http://en.wikipedia.org/wiki/File:Butanoic_acid.png.svg

• Aromatic aldehydes are usually designated as derivatives of the

simplest aromatic aldehyde, Benzaldehyde.

H O

O

p-Methoxybenzaldehyde

Anisic aldehyde m-Nitrobenzaldehyde Salicylaldehyde (o-hydroxybenzaldehyde)

Examples:

Benzaldehyde



http://en.wikipedia.org/wiki/File:3-nitrobenzaldehyde.svg

http://en.wikipedia.org/wiki/File:Salicylaldehyde.svg

http://en.wikipedia.org/wiki/File:Benzaldehyde.png

• Name the substituents attached to the chain in the usual way.

IUPAC Nomenclature of Aldehydes

• Select the longest carbon chain containing the carbonyl carbon.

• The -e ending of the parent alkane name is replaced by

the suffix -al.

• The carbonyl carbon is always numbered “1.” (It is not necessary to

include the number in the name.)

• The CHO group is assigned the number “1” position and takes

precedence over other functional groups that may the present such as

–OH, C=C .

• If the presence of another functional group demands the use

of a suffix, the aldehyde group is named with the prefix formyl-.



IUPAC Naming

Formaldehyde Acetaldehyde Propionaldehyde Butyraldehyde

Methanal Ethanal Propanal Butanal

Common:

IUPAC:

Examples

2-pentenal

O

H

CH3CH2CHC

H

OCH3

2-Methyl butanal

2-chloropropanal

O

Cl

3-hydroxypropanal

OHO



http://en.wikipedia.org/wiki/File:Formaldehyde-2D.svg

http://en.wikipedia.org/wiki/File:Acetaldehyde-tall-2D-skeletal.png

http://en.wikipedia.org/wiki/File:Propanal-skeletal.png

http://en.wikipedia.org/wiki/File:Butanal-skeletal.png

General formula: RCOR’ (R and R’=alkyl or aryl)

Common name: listing the alkyl substitutents attached to the

carbonyl group, followed by the word ketone.

IUPAC system: relpace the ending –ane by the suffix –one. The

chain is numbered in such a way as give the lowest number to the

C=O group.

If another group has priority, then the ketone group is called

"oxo“.

2) Ketones

C

O

RR



IUPAC:

Common:

acetone acetophenone Benzophenone

Diphenylketone Dimethylketone Methylphenylketone

Propanone diphenylmethanone 1-phenylethanone

1-Cyclopentyl propanone

Methyl isopropylketone

CH3C CH

O

CH3

CH3

3-Methylbutan-2-one

Ethylcyclopentylketone

Cyclobutanone

CH3CH2 C

OExamples:

Common & IUPAC Naming

O



http://en.wikipedia.org/wiki/File:Acetone-2D-skeletal.svg

http://en.wikipedia.org/wiki/File:Acetophenone-2D-skeletal.png

http://en.wikipedia.org/wiki/File:Benzophenon.svg

Physical Properties of Aldehydes and Ketones A. Boiling Points

CO

C O

CO

C O

CO

C O

CO

C O

Because of polarity of carbonyl groups, aldehydes and ketones are polar

compounds.

As a result, the boiling points of aldehydes and ketones are higher than those of

nonpolar alkanes, but lower than those of alcohols.

Dipole-dipole attractions, although important, are not as strong as intractions due

to hydrogen bonding.

Dipole-dipole interaction amang carbonyl compounds



B. Solubility in water The lower aldehydes and ketones are soluble in water because they form

hydrogen bonds with water.

C

O

HR

OH H

C

O

R'R

OH H

Intermolecular hydrogen bonding

between water and aldehydes

Intermolecular hydrogen bonding

between water and ketones.

Aldehydes and ketones with less than six carbons are essentialy

insoluble in water.

The higher aldehydes and ketones are soluble in organic solvents such as;

benzene, ether, and carbontetrachlorid.



Preparation of Aldehydes and Ketones

The major methods for preparing aldehydes an ketones are:

2. Ozonolysis of alkenes.

4.Friedel-Crafts acylation

1. Oxidation of alcohols

3.Hydration of alkynes



1. Oxidation of alcohols

The oxidation of primary alcohols, using mild oxidizing agents yields

aldehydes. [O] represents the oxidizing agent used.

When strong oxidizing agents are used, the aldehydes are very easily

oxidized to further carboxylic acids.

[O] = CrO3/ pyridine or Cu/ heat

1° alcohol An Aldehyde

Mild oxidizing agent

CH3CH2OH[O]

CH3CH

O

[O] = H2Cr2O7 Strong oxidizing agents

1° alcohol

A carboxylic acid

CH3CH2OH[O]

CH3CH

O

CH3COH

O



No Reaction

For oxidizing a tertiary alcohol, Nothing happens.

3° alcohol

OH

CH3CCH3

CH3

[O]

This reaction also illustrates the importance of differentiating

between primary, secondary, and tertiary alcohols.

Secondary alcohols, are converted either into ketones on treatment

with both mild or strong oxidizing agent.

2°

alcohol A Ketone

CH3CHCH3

OH[O]

CH3CCH3

O

[O] = may be CrO3/ pyridine ; Cu/ heat or H2Cr2O7



2. Ozonolysis of alkenes

1) O3

2) Zn, H2OCH2CH2 C

O

HCH

O

1) O3

2) Zn, H2OO +

H

O

Examples

General equation

Results in aldehydes or ketones depending on structure of the alkene

used.

(1) O3

(2) Zn, H2OC C

R

HR

R R

RC O

H

RCO+



R C C R + H2OHgSO4/ H2SO4

Water adds to alkynes in the presence of dilute sulfuric acid and

murcuric sulfate catalyst. to yield an enol. However the initially formed

enol reacts further to produce a ketone.

Such isomers, differing only in the placement of a hydrogen atom, are

called tautomers.

Enol form Keto form

General equation

More stable Less stable

3.Hydration of alkynes: Addition of water



Examples

H3C C

CH

+ H2OHgSO4/ H2SO4a)

Propyne

H3C C

CH2

OH H3C C

CH3

O

Acetone

C CH

+ H2OHgSO4/ H2SO4b)

1-Cyclohexyl acetylene



C CH

H

OH

C CH3

O

1-Cyclohexyl ethanadehyde 1-Cyclohexyl ethananone

4- Friedel-Crafts acylation

A general method for preparing ketones that contain an aromatic ring is

the Friedel-Crafts acylation reaction.

General equation

Examples

+ CH3CH2 C Cl

O

AlCl3 C CH2CH3 + HCl

O

Propionyl chloride

Propiophenone

Ethyl phenyl ketone

+ R C Cl

O

AlCl3 C R + HCl

O

The reaction involves treatment of an aromatic ring with an acylchloride,

, in the presence of AlCl3, which acts as a catalyst.

C

O

ClR



Reactions of Aldehydes and Ketones Aldehydes and ketones undergo nucleophilic addition reaction

to the carbon-oxygen double bond. 1. Addition of metal hydrides: Formation of alcohols.

2. Addition of Grignard Reagents : Formation of alcohols.

3-Oxidations of aldehydes and ketones:

a.Oxidation under acidic conditions/ H+

b. Under alkaline conditions/ OH-

5. Addition of Hydrogen cyanide: Formation of cyanohydin. 6- Nucleophilic addition of Acetylide ions:

7- Nucleophilic Addition of Alcohols:

Formation of Hemiacetals and Acetals.

8- Addition of Ammonia and Ammonia Derivatives.



4. Tollen’s Test: Silver mirror test.

9- Aldol condensation reaction.

10 - Cannizzaro reaction.

Catalytic hydrogenation reduces aldehydes to produce 1° alcohols & ketones

to produce 2° alcohols.

(conditions are very similar to those used to reduce alkene double bonds).

Lithium aluminum hydride; LiAlH4 is a very strong reducing agent that will

reduce many functional groups in addition to aldehydes and ketones.

Sodium borohydride; NaBH4 is a much weaker reducing agent that

basically will reduce only aldehydes and ketones to alcohols.

1. Addition of metal hydrides: Formation of alcohols.

Metal Hydrides; LiAlH4, NaBH4

H2/ Ni

Low Pressure

O

LiAlH4

H

OH

O OH

1)NaBH4

2)H2O



Exercise: Choose the best reagent for the following reactions.

Although the same result may be achieved by catalytic hydrogenation, or

LiAlH4 , but NaBH4 has the advantage of selectively reducing of unsaturated

aldehydes and ketones into unsaturated alcohols.

H2/Ni

LiAlH4

NaBH4 / CH3OH OH

Propanol

O

Propanal

A] or

or

Conclusion

NaBH4 / CH3OH

H2/Ni LiAlH4 or C]

O

Cyclopent-2-enone

OH

Cyclopentanol

OH

3-Phenyl-prop-2-en-1-ol

B]

3-Phenyl-prop-2-en-1-al

O



2. Addition of Grignard Reagents : Formation of alcohols.

Grignard reagents are strong nucleophiles that they can serve as nucleophilic

addition to carbonyl group.

Treatment of an aldehyde or ketone with Grignard reagent followed by water

forms an alcohol with new C-C bond.

Grignard reagents react with formaldehyde to produce primary alcohols.

1. In case of formaldehyde:

CH3MgBr + C

O

HH

1) Dry ether

2) H3O+

CH3CH2OH

General equation

Example:

RMgBr + C

O

HH

1) Dry Ether

2) H3O+

RCH2OH

Formaldehyde Ethanol

1° Alcohol



2. In case of other aldehyde:

Grignard reagents react with aldehyde to produce secondary alcohols.

General equation

Examples:

2° Alcohol Aldehyde

RMgBr + C

O

R'H

1) Dry Ether

2) H3O+ C

OH

R'

HR

Acetaldehyde 2-Butanol

CH3CH2MgBr + C

O

H

CH3

1) Dry ether

2) H3O+C

H

OH

CH3 CH2CH3



General equation 3. In case of Ketones:

Examples:

Grignard reagents react with ketones to produce tertiary alcohols.

O

1) Dry ether

2) H3O+

CH3MgBr + OH

CH3

3° Alcohol ketones

cyclohexanone cyclohexyl methyl alcohol

RMgBr + C

O

R''R'

1) Dry Ether

2) H3O+ C

OH

R''

R'R



3-Oxidations of aldehydes and ketones

Aldehydes can be oxidized to carboxylic acid with both mild and strong

oxidizing agents.

Typical oxidizing agents for aldehydes include either potassium permanganate

(KMnO4) or potassium dichromate (K2Cr2O7) in acid solution.

C H

O

KMnO4 /H+

C OH

O

Benzaldehyde Benzoic acid

Peroxy acids, such as peroxybenzoic acid (C6H5CO3H) are used to

oxidize ketones to esters.

a.Oxidation under acidic conditions/ H+

CH3

O

CH3Cl

C

O

OOHC6H5O

O

CH3

cyclohexylmethylketone cyclohexylacetate

Oxygen insertion

occurs between

carbonyl carbon

and larger group.



The iodoform test

CH3C

O

CH3C

OH

HThe compounds containing or , give iodoform test.

CH3C

O

R +3I2 + 4NaOH CHI3 + CH3COO- Na+ + 3H2O + 3NaI

The General equation

The iodoform test is a test for the existence an acetyl group, or

a group that can be oxidized to an acetyl group which will give a positive

iodoform test.

+ve Iodoform(CHI3) result =

is a pale yellow substance.

These type of methylketones can be distinguished from other non-methyl

ketone by their reaction with iodine; I2 in a basic solution; NaOH to yield

iodoform (CHI3) as a yellow colored precipitate.

b. Under alkaline conditions/ OH-

-ve

Iodoform



http://en.wikipedia.org/wiki/File:Acetyl_group.svg

http://upload.wikimedia.org/wikipedia/commons/c/c8/Jodoformprobe.jpg

Examples:

3I2NaOH+ CHI3 CH3C

O

H + C

O

ONaHa)

acetaldehyde

NaOHCHI3 + C

O

ONa

3I2+ CH3C

O

b)

acetophenone

3I2NaOH+ CHI3 CH3C

O

CH3 + C

O

ONaCH3

c)

acetone



Exercise:

Which of the following compounds will give a positive result +ve toward

iodofrom test:

HCHO

Compounds

CH3CHO

CH3COCH3

O

Results Why ??

-ve, No yellow ppt

+ve, gives yellow ppt

Has no CH3CO

Has no CH3CO

Has CH3CO

Has CH3CO

-ve, No yellow ppt

+ve, gives yellow ppt




Reaction Mechanism of haloform Chapter 6; Aldehydess& Ketoness

R CH3

Oexcess X2

NaOH R ONa

O+ CHX3

Overall reaction

This reaction happen when you have terminal ketone.

Haloform could be chloroform, bromoform and Iodoform.

Note that

α-hydrogens are more acidic due to the inductive effect

near by the halogen. As there are excess of halogen; the

halogen will replace all the methyl hydrogens.


O

H

Br

OH

NaOH

O

H

Br

OHO

H

BrBrNaOH

O

Br

Br

Br Br

Br Br

OBr

BrBr

OH

O

Br

BrOH Br

O

O

H C

Br

Br

Br

+

O

O

C

Br

Br

Br

+ HNa

O

H

H

HNaOH

O

H

H Br Br

Reaction Mechanism of haloform Chapter 6; Aldehydess& Ketoness

Reaction Mechanism


OH from sodium hydroxide will attract the –hydrogen add create

the enolate intermediat.


The enolate collapse back dawn and the 1st halogen adds to the

molecule.

The reaction happens twice till the three halogens are added.

OBr

BrBr

The presence of 3 halogen atoms on the carbon

makes it δ+ and difficult to act as leaving group. C δ+

In the presence of more molecules of NaOH in the solution the OH

will attack the C δ+ forming tetrahydral unstable intermediat.

The –ve oxygen will collapse back dawn to reform the double bond

and kick out the :CBr3 instead of OH.

Mechanism Description

The :CBr3 anion abstracts a proton from either the solvent or

the carboxylic acid formed in the previous step, and forms the

haloform and carboxylate ion.



4. Tollen’s Test: Silver mirror test. Tollen’s reagent (Ag(NH3)2

+ / OH- is a weak oxidant

Aldehydes are readily oxidized to carboxylic acids by Tollen’s

reagent to produce a silver mirror on the inside of a clean test tube.

Ketones are not oxidized by Tollen’s reagent.

https://www.youtube.com/watch?v=7I-y3I3VzM8

video link

R H

O

+ 2 Ag(NH3)2OH 2 Ag +R O NH4

O

+ H2O + 3 NH3

H

O

AgO2

NH3/ H2O

OH

O

+ Ag

General Equation

Example

Ammonium salt

of carboxylic acid Metalic silver is deposted

in a thin mirror coating












Experiment Observation Conclusion

Tollen’s test The colourless solution

produces a grey precipitate of

silver, or a silver mirror on the

test tube.

Aldehyde

Tollen’s test

No change in the colourless

solution

Ketone


5. Addition of Hydrogen cyanide: Formation of cyanohydin.

The nucleophilic addition of hydrogen cyanide (HCN) to aldehydes or

ketones affords Cyanohydrin.

(Cyanohydrin: A molecule containing an -OH group and a -CN group

bonded to the same carbon.

General equation

aldehydes or ketones Cyanohydrin

R H or R'

O

HCN, -CNR H or R'

OH

CN



Examples:

Benzaldehyde Benzaldehyde cyanohydrin

a) C HHCN, -CN

O

C H

OH

CN

b)

O

HCN, -CN

HO CN

Cyclohexanone Cyclohexanone cyanohydrin



Cyanohydrins are very useful because the CN group can be converted to

other functional groups.

For example: reduction with LiAlH4 followed by water reduces the

CN group to a primary amine. Thus an aminoalcohol product is formed.

Also, hydrolysis of the CN group with acidic water gives a hydroxy

carboxylic acid product. This affords us with an important method of

synthesizing α-hydroxy-carboxylic acids.

C H

OH

CN

1) LiAlH4

2) H2O

H3O+

heat

C H

OH

CH2NH2

C H

OH

COOH

2-Amino-1phenyl-ethanol

2-hydroxy-2-phenylacetic acid



6- Nucleophilic addition of Acetylide ions:

Acetylide ions are another example of organometallic reagents; it can be

thought of as “organo sodium reagents”. They are good nucleophiles.

The addition of acetylides ions to aldehydes and ketones yields an

alkynol.

(An alkynol: is an alcohol on carbon adjacent to triple bond.)

General equation

Acetylide ions can also used to attack carbonyl group, The net effect of

the reaction of organometallic reagents with an aldehyde or ketone is the

addition of the components R and H across the C=O double bond.

.

An alkynol



Examples:

b)

CH3 C C Na + C O

H

H

H3O+

CH3 C C C OH

H

H

a)

An alkynol, 1° alcohol Formaldehye

CH3 C C Na + C O

CH3

H

H3O+

CH3 C C C OH

H

CH3

Acetaldehye An alkynol, 2° alcohol

c) CH3 C C Na +

O

H3O+

OHCH3 C C

Cyclohexanone An alkynol, 3° alcohol



7- Nucleophilic Addition of Alcohols:

Formation of Hemiacetals and Acetals A.1 Hemiactals The addition of one mole of an alcohol to the carbonyl group of an aldehyde

yields a hemiacetal. (hemi, Greek, half).

An Aldehyde A hemiacetal An alcohol

R C

O

H + R' OH H+

CR OR'

OH

H

General equation

B.1 Acetals When hemiacetals are treated with an addition mole of an alcohol in

the presence of anhydous acid, they are converted to acetals .

CR OR'

OH

H

CR OR'

OR"

H

H+ (anhyd.)R" OH+General equation

A hemiacetal An alcohol Acetals Chem 340- 2nd semester 1437-1438


Example

The addition of one mole of an alcohol to the carbonyl group of a ketone

yields a hemiketal.

A.2 Hemiketals

Ethanal Methanol 1-Methoxyethanol

(A hemiacetal)

+ CH3OHCH3OH

CH3 C

O

H CCH3

OH

H

OCH3H+

H+(anhyd.)

CCH3

OCH3

H

OCH3

1,1-Dimethoxyethanol

(An acetal)

+ R' OH H+

CR OR'

OH

R"

R C

O

R"

A hemiketal A Ketone

General equation

An alcohol



B.2 Ketals

The reaction of hemiketal with alcohols to form ketals is seldom works.

CR OR'

OH

R"

H+ (anhyd.)R'" OH+ CR OR'

OR'"

R"

a hemiketal An alcohol ketals

The Conclusion

The hemiacetal and the hemi ketal are compounds that have an

alkoxy group (OR) & hydroxy group (OH) that are attached to

the same carbone.

The acetals & the ketals are compounds that have two

alkoxy groups (OR) on the same carbon. Chem 340- 2nd semester 1437-1438


Nitrogen nucleophiles such as ammonia and its derivatives H2N - Z add

to carbonyl group of aldehydes and ketones.

8- Addition of Ammonia and Ammonia Derivatives

The reaction is reversible and catalyszed by acid.

a) The Reaction with Hydroxylamine

Aldehydes and ketones react with hydroxylamine to form oximes.

C O

R

R' (H)

+ H2 NOH H+

C NOH + H2O

R

R' (H)

Hydroxylamine Oxime

The net result is replacement

of the >C = O group with >C = N - Z group

Aldehyde

or Ketone Chem 340- 2nd semester 1437-1438


Aldehydes and ketones react with hydrazine to form hydrazones.

b) The Reaction with Hydrazine

With aldehydes

With ketones

H++ H2 NNH2

C O

H

CH3

+ H2OC NNH2

H

CH3

Acetaldehyde Hydrazine Acetaldehyde

hydrazone

H++ H2 NNH2 + H2O

C O

CH3

CH3

C NNH2

CH3

CH3

Acetone Hydrazine Actone

hydrazone Chem 340- 2nd semester 1437-1438


c) The Reaction with ammonia NH3

Like ammonia derivatives ammonia also reacts with aldehydes (except

formaldehyde) and ketones to form the products called imines.

+ NH3 C

H

CH3 OH

NH2

C O

H

CH3

C NH

H

CH3-H2O

Acetaldehyde Ammonia Acetaldehyde

ammonia

Acetaldimine



Summary

Structure and names of nitrogen nucleophiles that react with

carbonyl compounds:

+

Nitrogen Nucleophile Nitrogen derivative

of carbonyl compounds

NH3Ammonia Imine

C N NH2NH2NH2Hydrazine Hydrazone

NH2OHHydroxylamine Oxime

C HN

C OHN

C O





http://web.chem.ucla.edu/~harding/notes/notes_14D_enolates.pdf





9- Aldol condensation


Aldol means aldehyde and alcohol groups on the same molecule.

May occur between two aldehydes (aldols) or two ketones

(ketols) in the presence of catalytic base.

Reaction ONLY possible between two components having

α-hydrogen.

- With Aldehydes, the equilbrium favors product

- With ketones, the equilbrium favors the sarting materials.

The reactions are reversible

HR

O

HR

O

+Dilute Alkali

HR

O

R

OH

O

+Dil. Ba(OH)2

O OHO


NaOH Na + OH


Aldol condensation Reaction Mechanism Step 1. Ionization of base

Step 2. Formation of acceptor electrophile

HR

O+ Na

HRONa

Step 3. The base removes an acidic alpha hydrogen from one aldehyde

molecule; yielding a resonance stabilized enolate ion (nucleophile).

HR

O

+OH

HR

O

Step 4. The enolate ion attacks a second aldehyde molecule in

nucleophilic addtion reaction to give a tetrahydral alkoxide ion

intermediate.

HRONa

HR

O+

HR

O

R

ONa

HR

O

R

OH

NaOH

H2O

Step 5. Protonation of the alkoxide ion intermediate yields neutral aldol

product and regenerate the base catalyst.


The aldol products formed often undergoes dehydration to form

conjugated systems. This reaction is a type of nucleophilic

addition

In some cases, the adducts obtained from the Aldol Addition can

easily be converted (in situ) to α,β-unsaturated carbonyl

compounds, either thermally or under acidic or basic catalysis

Note that:



O ONaH

H +

ONaO

NaOH

H2OOHO

Ketol condensation Reaction Mechanism

NaOH Na + OH

Step 1. Ionization of base

Step 2. Formation of acceptor electrophile

O

+OH

O

Step 3. Formation of donar enolate nucleophile

O+ Na

ONa


Step 4. The enolate ion attacks a second ketone molecule giving a

tetrahydral alkoxide ion intermediate.

Step 5. Protonation of the alkoxide ion intermediate yields neutral

ketol product and regenerate the base catalyst.


Dehydration is favorable because the product is stabilized

by conjugation of the alkene with the carbonyl group.

In similar manner dehydrates takes place in ketols to the

α,β -unsaturated compound.

The aldol product cannot be isolated.


Note That:



10- Cannizzaro Reaction

Upon treatment with strong bases (e.g. in aqueous NaOH)

and heating, non-enolizable aldehydes undergo redox

disproportionation to give corresponding alcohols and

carboxylic acids in 1:1 ratio.

General equation

Examples

2

2


Reaction Mechanism of Cannizzaro Reaction



Home Work Chapter 6; Aldehydess& Ketoness

Q.1 Each of the following compounds was prepared by an aldol

condensation followed by dehydration. In each case, select the

structure of the starting material from the list of choices in the box

below.


Q.2. Give the IUPAC name for the following.


O

Br

O

…………………………………… ……………………………………

A) B)

Acetone Propan-1-ol Propanal n-Butane Methoxyethane

(i) (ii) (iii) (iv) (v)

Q.3 Arrange these compounds in order of increasing

Boiling point.

Thank you For your attention


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