Aldehydes, Ketones & Carboxylic Acids

IUPAC names of open chain aldehydes

Aldehydes are organic compounds that contain a carbonyl group (C=O) at the end of a carbon chain.
The IUPAC naming of open chain aldehydes is based on the parent alkane and the suffix “-al” is added to indicate the presence of the aldehyde group.
The carbon chain is numbered starting from the end closest to the aldehyde group.
The terminal carbon atom of the chain, bearing the aldehyde group, is assigned number 1.
The position of the aldehyde group is indicated by the numerical prefix and the name of the alkane chain.
For example, methanal is the IUPAC name for formaldehyde. Example:
Methanal (formaldehyde) has the aldehyde group (-CHO) attached to the first carbon atom of a one-carbon chain. Equation:
H-C=O (aldehyde group)

IUPAC names of open chain aldehydes (cont.)

If the aldehyde group is attached to a longer chain, the name of the alkane chain is modified to indicate the position of the aldehyde group.
The carbon chain is numbered to give the aldehyde group the lowest possible number.
Aldehydes with more than three carbons are named using the suffix “-aldehyde”. Examples:

Ethanal (acetaldehyde) has the aldehyde group (-CHO) attached to the second carbon atom of a two-carbon chain.

Butanal has the aldehyde group (-CHO) attached to the first carbon atom of a four-carbon chain. Equations:

Aldehydes, Ketones & Carboxylic Acids

IUPAC names of open chain aldehydes (cont.)

If there are branches or substituents on the carbon chain, the position of the aldehyde group is indicated by numbering the main chain to give the aldehyde group the lowest possible number.
The branches or substituents are specified using prefixes like “methyl”, “ethyl”, etc., and their positions are indicated by the numbers. Example:
3-Methylbutanal has the aldehyde group (-CHO) attached to the third carbon atom of a five-carbon chain, with a methyl group (-CH3) attached to the second carbon atom. Equation:
CH3-CH(CH3)-CH2-CHO (3-methylbutanal)

Aldehydes, Ketones & Carboxylic Acids

IUPAC names of open chain aldehydes (cont.)

Sometimes, cyclic aldehydes are encountered.
In cyclic aldehydes, the carbonyl group is attached to a carbon atom within the ring structure.
The suffix “-carbaldehyde” is used to indicate the presence of the aldehyde group in cyclic aldehydes. Example:
Cyclopentanecarbaldehyde has the aldehyde group (-CHO) attached to a carbon atom within a cyclic five-carbon structure. Equation:
Cyclic Structure: C-C-C-C-C
```
               |
```
```
    H-C=O (aldehyde group)
```

Aldehydes, Ketones & Carboxylic Acids

IUPAC names of ketones

Ketones are organic compounds that contain a carbonyl group (C=O) attached to two carbon atoms within a carbon chain.
The IUPAC naming of ketones is based on the parent alkane and the suffix “-one” is added to indicate the presence of the ketone group.
The carbon chain is numbered starting from the end closest to the carbonyl group.
The position of the carbonyl group is indicated by the numerical prefix and the name of the alkane chain. Example:
Propanone (acetone) has the ketone group (C=O) attached to the second carbon atom of a three-carbon chain. Equation:
CH3-CO-CH3 (propanone)

Aldehydes, Ketones & Carboxylic Acids

IUPAC names of ketones (cont.)

If there are branches or substituents on the carbon chain, the position of the carbonyl group is indicated by numbering the main chain to give the ketone group the lowest possible number.
The branches or substituents are specified using prefixes like “methyl”, “ethyl”, etc., and their positions are indicated by the numbers. Example:
3-Methylpentan-2-one has the ketone group (C=O) attached to the second carbon atom of a five-carbon chain, with a methyl group (-CH3) attached to the third carbon atom. Equation:
CH3-CH2-CH(C=O)-CH2-CH3 (3-methylpentan-2-one)

Aldehydes, Ketones & Carboxylic Acids

IUPAC names of carboxylic acids

Carboxylic acids are organic compounds that contain a carboxyl group (-COOH) attached to a carbon atom within a carbon chain.
The IUPAC naming of carboxylic acids is based on the parent alkane, with the suffix “-oic acid” added to indicate the presence of the carboxyl group.
The carbon chain is numbered starting from the end closest to the carboxyl group.
The position of the carboxyl group is indicated by the numerical prefix and the name of the alkane chain. Example:
Ethanoic acid (acetic acid) has the carboxyl group (-COOH) attached to the second carbon atom of a two-carbon chain. Equation:
CH3-COOH (ethanoic acid)

Aldehydes, Ketones & Carboxylic Acids

IUPAC names of carboxylic acids (cont.)

If there are branches or substituents on the carbon chain, the position of the carboxyl group is indicated by numbering the main chain to give the carboxyl group the lowest possible number.
The branches or substituents are specified using prefixes like “methyl”, “ethyl”, etc., and their positions are indicated by the numbers. Example:
2-Methylpropanoic acid has the carboxyl group (-COOH) attached to the second carbon atom of a three-carbon chain, with a methyl group (-CH3) attached to the second carbon atom. Equation:
CH3-CH(COOH)-CH3 (2-methylpropanoic acid)

Aldehydes, Ketones & Carboxylic Acids

Summary

Aldehydes are named by adding the suffix “-al” to the alkane name.
Ketones are named by adding the suffix “-one” to the alkane name.
Carboxylic acids are named by adding the suffix “-oic acid” to the alkane name.
The position of the functional group is indicated by numbering the carbon chain and specifying the position of any branches or substituents. Example:
Methanal (formaldehyde): H-C=O
Ethanal (acetaldehyde): CH3-CH=O
Butanal: CH3-CH2-CH2-CHO
3-Methylbutanal: CH3-CH(CH3)-CH2-CHO
Cyclopentanecarbaldehyde: Cyclic Structure: C-C-C-C-C H-C=O
Propanone (acetone): CH3-CO-CH3
3-Methylpentan-2-one: CH3-CH2-CH(C=O)-CH2-CH3
Ethanoic acid (acetic acid): CH3-COOH
2-Methylpropanoic acid: CH3-CH(COOH)-CH3

Aldehydes, Ketones & Carboxylic Acids

Slide 11

Aldehydes contain a carbonyl group (C=O) at the end of a carbon chain.
Aldehydes serve as important intermediates in various chemical reactions.
Some common aldehydes include formaldehyde, acetaldehyde, and butyraldehyde.
Aldehydes can be prepared by the oxidation of primary alcohols or by the reduction of carboxylic acids. Example:
Formaldehyde is used in the production of resins and plastics. Equation:
H-C=O (aldehyde group)

Aldehydes, Ketones & Carboxylic Acids

Slide 12

Ketones contain a carbonyl group (C=O) attached to two carbon atoms within a carbon chain.
Ketones have a wide range of applications, such as solvents, flavorings, and pharmaceuticals.
Some common ketones include acetone, butanone, and cyclohexanone.
Ketones can be prepared by the oxidation of secondary alcohols or by the ozonolysis of alkenes. Example:
Acetone is commonly used as a solvent. Equation:
C=O (ketone group)

Aldehydes, Ketones & Carboxylic Acids

Slide 13

Carboxylic acids contain a carboxyl group (-COOH) attached to a carbon atom within a carbon chain.
Carboxylic acids are important in biological systems, as they are involved in various metabolic processes.
Some common carboxylic acids include acetic acid, formic acid, and benzoic acid.
Carboxylic acids can be prepared by the oxidation of primary alcohols or by the hydrolysis of nitriles. Example:
Acetic acid is the main component of vinegar. Equation:
COOH (carboxyl group)

Aldehydes, Ketones & Carboxylic Acids

Slide 14

Aldehydes undergo various chemical reactions, such as nucleophilic addition, oxidation, and reduction.
Aldehydes can be converted into primary alcohols through reduction reactions.
Oxidation of aldehydes results in the formation of carboxylic acids.
Aldehydes can undergo nucleophilic addition reactions with nucleophiles such as cyanide ion, Grignard reagents, and alcohols. Example:
The reduction of acetaldehyde (CH3CHO) produces ethanol (CH3CH2OH). Equation:
CH3CHO + 2[H] → CH3CH2OH

Aldehydes, Ketones & Carboxylic Acids

Slide 15

Ketones can undergo nucleophilic addition reactions with nucleophiles such as cyanide ion, Grignard reagents, and alcohols.
Ketones do not undergo oxidation reactions under normal conditions.
Ketones can be converted into secondary alcohols through reduction reactions.
Ketones can undergo dehydration reactions to form alkenes. Example:
The reduction of acetone (CH3COCH3) produces 2-propanol (CH3CH(OH)CH3). Equation:
CH3COCH3 + 2[H] → CH3CH(OH)CH3

Aldehydes, Ketones & Carboxylic Acids

Slide 16

Carboxylic acids are acidic in nature due to the presence of the carboxyl group.
Carboxylic acids can undergo nucleophilic substitution and esterification reactions.
Carboxylic acids can be reduced to primary alcohols using reducing agents.
Carboxylic acids can undergo decarboxylation reactions under certain conditions. Example:
The reduction of ethanoic acid (CH3COOH) produces ethanol (CH3CH2OH). Equation:
CH3COOH + 2[H] → CH3CH2OH

Aldehydes, Ketones & Carboxylic Acids

Slide 17

Reactions of aldehydes and ketones with primary amines result in the formation of imines.
The reaction between aldehydes and secondary amines leads to the formation of enamines.
Aldehydes and ketones can undergo condensation reactions with alcohols to form hemiacetals and acetals.
Reactions of aldehydes and ketones with cyanide ion result in the formation of cyanohydrins. Example:
The reaction between benzaldehyde and ammonia produces benzaldehyde imine. Equation:
C6H5CHO + NH3 → C6H5CH=NH

Aldehydes, Ketones & Carboxylic Acids

Slide 18

Carboxylic acids can undergo esterification reactions with alcohols to form esters.
The reaction between carboxylic acids and alcohols is an equilibrium reaction, catalyzed by acids or bases.
Hydrolysis of esters results in the formation of carboxylic acids and alcohols.
Esterification reactions are widely used in the synthesis of fragrances, flavors, and plasticizers. Example:
The reaction between acetic acid and ethanol produces ethyl acetate. Equation:
CH3COOH + CH3CH2OH → CH3COOCH2CH3 + H2O

Aldehydes, Ketones & Carboxylic Acids

Slide 19

Aldehydes and ketones can undergo oxidation reactions to form carboxylic acids.
Oxidation of aldehydes can be achieved using mild oxidizing agents such as Tollens’ reagent or Fehling’s solution.
Ketones do not usually undergo oxidation reactions under normal conditions.
Oxidation-reduction reactions of aldehydes and ketones are important in various biological processes. Example:
The oxidation of ethanol (CH3CH2OH) produces ethanoic acid (CH3COOH). Equation:
CH3CHOH + [O] → CH3COOH + H2O

Aldehydes, Ketones & Carboxylic Acids

Slide 20

Carboxylic acids can undergo decarboxylation reactions under certain conditions, leading to the loss of a carbon dioxide molecule.
Decarboxylation is often observed in the metabolism of fatty acids and in the preparation of carbon dioxide gas.
Decarboxylation reactions involve the removal of a carboxyl group (-COOH) from the carboxylic acid. Example:
The decarboxylation of acetic acid (CH3COOH) produces carbon dioxide gas (CO2). Equation:
CH3COOH → CO2 + H2O

Aldehydes, Ketones & Carboxylic Acids - IUPAC names of open chain aldehydes

Aldehydes are organic compounds that contain a carbonyl group (C=O) at the end of a carbon chain.
The IUPAC naming of open chain aldehydes is based on the parent alkane and the suffix “-al” is added to indicate the presence of the aldehyde group.
The carbon chain is numbered starting from the end closest to the aldehyde group.
The position of the aldehyde group is indicated by the numerical prefix and the name of the alkane chain.
For example, methanal is the IUPAC name for formaldehyde. Example:
Methanal (formaldehyde) has the aldehyde group (-CHO) attached to the first carbon atom of a one-carbon chain. Equation:
H-C=O (aldehyde group)

Aldehydes, Ketones & Carboxylic Acids - IUPAC names of open chain aldehydes (cont.)

If the aldehyde group is attached to a longer chain, the name of the alkane chain is modified to indicate the position of the aldehyde group.
The carbon chain is numbered to give the aldehyde group the lowest possible number.
Aldehydes with more than three carbons are named using the suffix “-aldehyde”. Examples:

Ethanal (acetaldehyde) has the aldehyde group (-CHO) attached to the second carbon atom of a two-carbon chain.

Butanal has the aldehyde group (-CHO) attached to the first carbon atom of a four-carbon chain. Equations:

Aldehydes, Ketones & Carboxylic Acids - IUPAC names of open chain aldehydes (cont.)

If there are branches or substituents on the carbon chain, the position of the aldehyde group is indicated by numbering the main chain to give the aldehyde group the lowest possible number.
The branches or substituents are specified using prefixes like “methyl”, “ethyl”, etc., and their positions are indicated by the numbers. Example:
3-Methylbutanal has the aldehyde group (-CHO) attached to the third carbon atom of a five-carbon chain, with a methyl group (-CH3) attached to the second carbon atom. Equation:
CH3-CH(CH3)-CH2-CHO (3-methylbutanal)