Preparation of Aldehydes and Ketones

Preparation of Aldehydes and Ketones

From Acyl Chlorides

• Aldehydes can be prepared from acyl chlorides by treating them with hydrogen peroxide (H2O2) in the presence of a catalyst, such as potassium iodide (KI) or potassium bromide (KBr).
• This reaction is known as the Rosenmund reduction.

From Nitriles

• Aldehydes can be prepared from nitriles by treating them with diisobutylaluminium hydride (DIBAL-H) or lithium aluminium hydride (LiAlH4) in a reducing environment.
• Ketones can be prepared from nitriles by treating them with a strong base, such as sodium amide (NaNH2), followed by hydrolysis with water.

From Esters

• Aldehydes can be prepared from esters by treating them with diisobutylaluminium hydride (DIBAL-H) in a reducing environment.

From Benzene or Substituted Benzenes

• Ketones can be prepared from benzene or substituted benzenes by treating them with a strong oxidizing agent, such as chromium trioxide (CrO3) in the presence of sulfuric acid (H2SO4).
• This reaction is known as the Friedel-Crafts alkylation.
• Ketones can also be prepared from benzene or substituted benzenes by treating them with a alkyl halide in the presence of a Lewis acid, such as aluminium chloride (AlCl3).

Learn about the different methods of preparing aldehydes and ketones, including from acyl chlorides, nitriles, esters, hydrocarbons, and more. Understand the chemical reactions involved in each method.