Aldehyde, Ketones, and Carboxylic Acid Derivatives

Aju Nice

Oxidative Methods
• alkenes to aldehydes to carboxylic acid
•alkynes to carboxylic acid
• alkyl benzene io benzoic acid
• primary alcohols to aldehydes to carboxylic acid
• aldehyde to carboxylic acid

Aldehyde

class of organic compounds that have a carbonyl group
• any of a class of organic compounds in which a carbon atom shares a double bond with an oxygen atom, a single bond with a hydrogen atom, and a single bond with another atom or group of atoms
• some types are additive to fules
• used in fragrances, dyes, and pigments

Formaldehyde

• a type of gas, it is flammable and widely used to make home building products
• used in preservatives and disinfectants

Acetaldehyde

• highly reactive and non toxic
• generated during alcohol metabolism
• high levels of acetaldehyde can create a heightened and unpleasant response to alcohol characterized by facial flushing, headache, and nausea

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(Acetaldehyde) has an increasing boiling point and melting point with molecular mass
• Higher boiling point than hydrocarbons and lower boiling point than alcohols
• Polar and Soluble, it can form/accept hydrogen bonds from water molecules
• more soluble than hydrocarbons and less soluble than alcohols

Methanal

The boiling point of __________ is - 19 o C and for ethanal it is +21 o C. From this, we can say that the boiling point of ethanal is close to room temperature. Generally, the boiling point of aldehyde increases with an increase in molecular weight. This is because the boiling point depends upon the strength of the intermolecular forces

Aldehydes

cannot form hydrogen bonds with themselves, but they can have hydrogen bonds with water molecules and this forms the basis for good solubility of aldehydes and ketones in water.

Aldehydes

Are commonly prepared by the oxidation of alcohols whose -OH functional group is located on the carbon atom at the end of the chain of carbon atoms in the alcohol

Aldehyde

An alcohol with its -OH group bonded to a carbon atom that is bonded to no or one other carbon atom will form an

Are readily oxidized to carboxylic acids. The presence of that hydrogen atom is makes aldehydes easier to oxidize. Moreover,
_____________ have a proton attached to the carbonyl carbon which can be abstracted.

-al

The IUPAC system of nomenclature assigns a characteristic suffix ________ to aldehydes.

formaldehyde

(Aldehyde)
H2C=0 is methanal, more commonly called _______________. Since an aldehyde carbonyl group must always lie at the end of a carbon chain, it is always is given the #1 location position in numbering.

Carboxylic Acid and Ketone

Aldehyde has higher priority than alcohol, alkene, alkyne, and alkanes but lower than

Ketone

are organic compounds characterized by a carbonyl group (C=0) bonded to two carbon atoms. Their general formula is R1(C=0)R2, where R1 and R2 represent hydrocarbon chains.

CH3COCH3

The simplest ketone is acetone, with the formula _________________

Ketosis

Ketones can be formed through the oxidation of secondary alcohols in chemical reactions and are also produced in the body during fat metabolism, especially when carbohydrate intake is low, leading to a metabolic state known as

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Ketones have various applications, including use as solvents in industrial processes, in the production of plastics, and in pharmaceuticals. Their solubility in water, due to the polar nature of the carbonyl group, and thei reactivity in chemical reactions make them important in both scientific research and everyday products.

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Ketones exhibit a range of PHYSICAL properties that stem from their molecular structure. Here are some key characteristics:
State and Appearance
• Physical State: Most small ketones, such as acetone and methyl ethyl ketone, are liquids at room temperature.
Larger ketones may be solids.
•
Color: Generally, ketones are colorless.

dipole-dipole interactions

Boiling Points: Ketones typically have higher boiling points than alkanes of similar molecular weight due to the presence of the polar carbonyl group, which allows for

Solubility

Small ketones (like acetone) are generally soluble in water due to their polar carbonyl group, which can form hydrogen bonds with water molecules. As the carbon chain length increases, solubility in water decreases. Solubility in Organic Solvents:
Ketones are typically soluble in many organic solvents, including alcohols, ethers, and hydrocarbons.

Density

Ketones usually have densities greater than water but less than that of most organic compounds. For example, the density of acetone is about 0.79 g/cm'.

Odor

Many ketones have distinctive odors. For instance, acetone has a sweet, fruity smell, while larger ketones may have varying scents.

Nucleophilic Addition

They can react with nucleophiles, leading to the formation of alcohols.

Oxidation

Ketones can be oxidized to carboxylic acids under strong conditions.

Aldo Condensation

They can combine with other ketones or aldehydes to form larger molecules.

Reaction with Alcohols

Ketones can react with alcohols to create hemiketal and ketals.

Haloform Reaction

Ketones with a methyl group next to the carbonyl can react with halogens to produce compounds like iodoform.

Reaction with Amines

They react with primary amines to form imines and with secondary amines to create enamines.
These properties make ketones useful in many chemical reactions and applications

NUMENCLETURE

Steps for Naming Ketones
Identify the Longest Carbon Chain: Determine the longest continuous carbon chain that contains the carbonyl group (C=0).

Propanone (CH3COCH3)

Acetone:
The simplest ketone, also known as

Butan-2-one

A four-carbon chain with the carbonyl group on the second carbon

3-Pentanone

A five-carbon chain with the carbonyl group on the third carbon

Cyclohexanone

A cyclic ketone with the carbonyl group as part of the ring structure

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Special Cases
Complex Structures: For more complex ketones, follow the same naming conventions but be mindful of additional structural features that may require prefixes or other descriptors.
Common Names: Some ketones have well-known common names, like "acetophenone" for phenyl methyl ketone, which may be used instead of systematic names.

Ketone nomenclature

involves identifying the longest carbon chain, numbering it to give the carbonyl group the lowest number, naming the parent alkane with the "-one" suffix, indicating the carbonyl position, and including any substituents in alphabetical order. These rules ensure clarity and consistency in naming ketones.

Surfactant Properties

While soaps are typically made from fatty acids and glycerol, some detergents can contain ketone derivatives as part of their formulation. Ketones can help enhance the solubility of various ingredients, contributing to the overall surfactant properties of the detergent.

Solvent Action

Ketones, like acetone or methyl ethyl ketone, are effective solvents. They can help dissolve oils and grease, making them useful in some cleaning products. In formulations, these ketones can assist in breaking down stains or residues that traditional soaps may struggle with.

Fragrance and Odor

Ketones can also contribute to the fragrance of soaps and detergents. Some ketones have pleasant scents and are used as fragrance compounds, enhancing the sensory experience of using these products.

Chemical Stability

Ketones can add to the chemical stability of certain formulations. They can act as intermediates or stabilizers, improving the shelf life of soaps and detergents.

Biodegradability

While traditional soaps are often more biodegradable, some synthetic detergents containing ketones may have varying degrees of environmental impact. The use of biodegradable ketone derivatives in detergents can help reduce environmental concerns associated with synthetic surfactants.

Carboxylic Acid

an organic compound containing a carboxyl functional group.
• Contain the -COOH group.
• are organic compounds characterized by the presence of the carboxyl

Carboxylic Acid

• contains the carboxylic group
• combination of carbonyl group and hydroxyl group
• derivatives: acid halide, acid anhydride, ester, amide

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carboxylic acids have higher boiling points and melting points than alcohols
• acid chlorides, acid anhydrides and ester have similar boiling points with aldehydes and ketones, but have lower boiling points than alcohols and carboxylic acids
• amides have high boiling points because of the presence of hydrogen bonding

Acid Halide

Carbonyl bound to halogen

Acid Anhydride

an oxide that forms an acid when reacted with water

Ester

an organic compound made by chemically combining an alcohol and an organic acid

Amines

organic compounds with an amino group

Ammonia

• contains amino group
• can be in a chain (straight or branched), or in a ring (heterocyclic amine), or in a ring
• if highest priority: suffix = -amine
• if as a substituent: prefix = amino-

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polar substances (similar with ammonia)
• can undergo hydrogen bonding with water and with itself (but not all
• thus, small amine molecules are soluble in water
• have higher boiling point than nonpolar compounds
• however, have lower boiling point than alcohols and carboxylicacids
• soluble in less polar solvents such as ether, alcohol, benzene
• smells like ammonia
• aromatic amines: generally toxic
• similar with ammonia: has basic pH

Detection of Aldehydes and Ketones

2, 4 DNP Test
1. Add 1 ml 95% ethanol
2. Add 1-2 drops of sample
3. Add 1 ml of 2, 4 DNP
4. Shake and let it stand for 15 minutes
- positive result: formation of yellow-orange-red precipitate
- aliphatic = yellow
- aromatic = red

Detection of Aldehydes

Tollen's Test
• 1. Add 1.5 ml of Tollen's reagent
• 2. Add 4 drops of sample
• 3. Shake
• 4. Heat in water bath
• - positive result: formation of silver mirror at the bottom

Detection of Aliphatic Aldehydes

Benedict's Test
- Reagent: CuSO4 in sodium citrate
1. Add 1 ml of Benedict's reagent
2. Add 5 drops of sample
3. Put the solution in water bath
- positive result: discoloration of light blue solution and formation of red-brown precipitate

Detection of Methyl Ketone

lodoform Test
Reagent: K1/12
1. Add 1 ml of NaOH
2. Add 4 drops of sample
3. Add KI/12 dropwise with shaking
4. Warm to 60°C
Figu
5. If solution is colorless, repeat step 3 and 4
- positive result: formation of yellow precipitate

Detection of Carboxylic Acids

Esterification - ester formation
- reagent: ethanol
1. Add 2 drops of sample
2. Add 5 drops of ethanol
3. Add 1 drop of concentrated sulfuric acid
4. Warm the solution
- positive result: the solution has a pleasant smell

Detection of Esters

Hydroxamic acid for Esters
- reagent: 0.5 M hydroxylamine in 95% ethanol
1. Add 2 drops of sample
2. Add 3 drops of alcohol NH2OH _ HCI
3. Add 2 drops of NaOH
4. Heat to boil
5. Add drops of 2 M HCI until it becomes acidic
6. If solution becomes cloudy: add 1 ml of 95% ethanol
7. Add 2 drops of FeCI3 solution
- positive result: formation of magenta-colored complex with
FeCI3