1. Combustion of Alcohols•Alcohols can react like hydrocarbons with oxygen to create carbon dioxide and water.•Example: propanol + oxygen → carbon dioxide + waterC3H7OH (l) + O2 (g) → CO2 (g) + H2O (g)
2. Elimination of Alcohols•Alcohols can be converted to alkenes through elimination – specifically dehydration.•In a dehydration, the hydroxyl group and an adjacent hydrogen are removed and a double bond is formed.•This reaction requires a sulfuric acid catalyst.
3a. Substitution with Alcohols•Alcohols can be converted to alkyl halides only in the presence of a strong acid that contains a halogen, like HCl (aq). •This reaction can happen with any alcohol, but is very slow with both primary and secondary alcohols, as pulling off the nucleophile hydroxide to exchange it with a halide is not desirable. This reaction happens more quickly with tertiary alcohols.
3b. Substitution with AminesSubstitution can also occur with amines and alkyl halides to create more complex amines (secondary or tertiary).
4a. Oxidation of Alcohols•Oxidation is defined as a reaction in which a carbon atom forms more bonds to oxygen, or fewer bonds to hydrogen.•Alcohols can be converted to aldehydes and ketones through controlled oxidation, which is actually a type of elimination reaction. •In this type of reaction, an oxidizing agent, such as hydrogen peroxide (H2O2), potassium permanganate (KMnO4) or potassium dichromate (K2Cr2O7) is added to the alcohol and allowed to slowly react – the oxidizing agent is not present in excess. If it was, combustion would occur instead.•Primary alcohols will create aldehydes, and secondary alcohols will create ketones. These reactions do not happen with tertiary alcohols.
4b. Oxidation of AldehydesAn aldehyde can further be converted to a carboxylic acid through an oxidation reaction. Ketones cannot be converted to acids.
Butanal + [O] →
5a. Reduction of Carbonyls•Reduction is defined as a reaction in which a carbon atom forms fewer bonds to oxygen, or more bonds to hydrogen.•Aldehydes and ketones can be converted back to alcohols through a hydrogenation reaction when a reducing agent, such as lithium aluminum hydride, LiAlH4, or hydrogen over a platinum catalyst, is present.
5b. Reduction of CarboxylsCarboxylic acids can be converted back to aldehydes through a hydrogenation reaction when a reducing agent and a platinum catalyst are present.
Butanoic Acid + [H] →
6a. Condensation to Ethers•A condensation reaction is one in which two large molecules combine and form one larger molecule and one very small molecule, usually water. In simple terms, water is removed to form one molecule. •Condensation is important in all living systems – these type of reactions form most of the large biomolecules, such as proteins, carbohydrates, fats, and DNA.•Two alcohols can undergo condensation to form an ether and water. A sulfuric acid catalyst is necessary.
6b. Condensation to EstersCarboxylic acids can react with alcohols to form esters. A sulfuric acid catalyst is necessary.
Propanoic acid + Pentan-1-ol →
6c. Condensation to AmidesCarboxylic acids can react with amines to form amides.
Butanoic Acid + propan-1-amine →
7a. Hydrolysis of Esters•A hydrolysis reaction is essentially the reverse of a condensation reaction. It means “breaking apart using water”. •The compounds that are formed in condensation can be broken down by hydrolysis. The hydroxyl in a water molecule is added to one side of a bond such as an ester or amide, and the hydrogen is added to the other side, which breaks the bond.•Esters react with water to form alcohols and carboxylic acids.
7b. Hydrolysis of AmidesAmides react with water to form amines and carboxylic acids.
N-propyl-2-methylpropanamide + Water →
Functional Group
Reactions Type Conditions
Alcohols Alcohol + Oxygen → Carbon Dioxide + WaterAlcohol → Alkene + WaterAlcohol + Acid Halide → Alkyl Halide + WaterAlcohol + Alcohol → Ether + WaterPrimary Alcohol + [O] → Aldehyde + WaterSecondary Alcohol + [O] → Ketone + WaterAlcohol + Carboxylic Acid → Ester + Water
CombustionEliminationSubstitutionCondensationOxidationOxidationCondensation
H2SO4
H2SO4
Oxidizing AgentOxidizing AgentH2SO4, heat
Ethers NONE
Aldehydes Aldehydes + [O] → Carboxylic AcidAldehydes + [H] → Primary Alcohol
OxidationReduction
Oxidizing AgentPt, heat, pressure
Ketones Ketone + [H] → Secondary Alcohol Reduction Pt, heat, pressure
Carboxylic Acids
Carboxylic Acid + [H] → Aldehyde + WaterCarboxylic Acid + Alcohol → Ester + WaterCarboxylic Acid + Amine → Amide + Water
ReductionCondensationCondensation
Pt, heat, pressure H2SO4, heat
Esters Ester + Water → Carboxylic Acid + Alcohol Hydrolysis
Amines Amine + Alkyl Halide → Amine (of higher bonds)Amine + Carboxylic Acid → Amide + Water
SubstitutionCondensation
Amides Amide + Water → Amine + Carboxylic Acid Hydrolysis