Organic Synthesis: Aliphatic Compounds - A-Level Chemistry

Organic Synthesis: Aliphatic Compounds

Synthesis of Aliphatic Compounds

• Aliphatic compounds are synthesized through various reactions, which involve different functional groups
• The synthesis of each functional group is summarized in a flow diagram

Synthesis of Alkanes

• Alkanes are made from alkenes through hydrogenation reactions

Synthesis of Alkenes

• Alkenes are made from alkanes through cracking reactions

Synthesis of Halogenoalkanes

• Halogenoalkanes are made from alkanes through electrophilic substitution reactions
• For example, bromoethane (CH₃CH₂Br) is synthesized from ethane through the following steps:
  • Initiation: Br₂ → 2Br∙
  • Propagation: CH₃CH₃ + Br∙ → HBr + CH₃CH₂∙, CH₃CH₂∙ + Br₂ → CH₃CH₂Br + Br∙
  • Termination: CH₃CH₂∙ + Br∙ → CH₃CH₂Br

Synthesis of Alcohols

• Alcohols are made from alkenes through hydration reactions

Synthesis of Aldehydes

• Aldehydes are made from primary alcohols through oxidation reactions

Synthesis of Ketones

• Ketones are made from secondary alcohols through oxidation reactions

Synthesis of Hydroxynitriles

• Hydroxynitriles are made from aldehydes or ketones through nucleophilic addition reactions

Synthesis of Carboxylic Acids

• Carboxylic acids are made from aldehydes through oxidation reactions

Synthesis of Esters

• Esters are made from carboxylic acids and alcohols through esterification reactions

Synthesis of Amides

• Primary amides are made from carboxylic acids and ammonia through nucleophilic addition reactions
• Secondary amides are made from carboxylic acids and primary amides through nucleophilic addition reactions

Synthesis of Amines

• Amines are made from halogenoalkanes through nucleophilic substitution reactions

Synthesis of Nitriles

• Nitriles are made from carboxylic acids through dehydration reactions

Worked Example

• Reaction pathway 1 involves hydrogenation reactions, and the reaction conditions are high pressure and temperature, and the presence of a catalyst
• Reaction pathway 2 involves electrophilic substitution reactions, and the reaction conditions are the presence of a halogen and a catalyst
• Compound Z contains hydroxynitrile groups, and the reaction conditions for reaction 3 involve the presence of a nucleophile and a catalyst

Prepare for your A-Level Chemistry exam by learning the synthesis of aliphatic compounds, including alkanes and alkenes. This quiz covers the step-by-step synthesis of different organic compounds along with a flow diagram summarizing the process.