12.1: The Oxidation of Alcohols Oxidation by Chromic Acid Oxidation by PCC (pyridinium chlorochromate) 12.2: Oxidation of Aldehydes and Ketones This page looks at ways of distinguishing between aldehydes and ketones using oxidizing agents such as acidified potassium dichromate(VI) solution, Tollens' reagent, Fehling's solution and Benedict's solution. 12.3: Reaction with Primary Amines to form Imines The reaction of aldehydes and ketones with ammonia or 1º-amines forms imine derivatives, also known as Schiff bases (compounds having a C=N function). Water is eliminated in the reaction, which is acid-catalyzed and reversible in the same sense as acetal formation. The pH for reactions which form imine compounds must be carefully controlled. 12.4: Reduction of Aldehydes and Ketones This page looks at the reduction of aldehydes and ketones by two similar reducing agents - lithium tetrahydridoaluminate(III) (also known as lithium aluminium hydride) and sodium tetrahydridoborate(III) (sodium borohydride). 12.5: Reduction of Carbonyls to Alcohols Using Metal Hydrides The most common sources of the hydride nucleophile are lithium aluminum hydride and sodium borohydride. In metal hydrides reductions the resulting alkoxide salts are insoluble and need to be hydrolyzed (with care) before the alcohol product can be isolated. In the sodium borohydride reduction the methanol solvent system achieves this hydrolysis automatically. In the lithium aluminum hydride reduction water is usually added in a second step. 12.6: Making Carboxylic Acids by Oxidation of Primary Alcohols or Aldehydes 12.7: Making Carboxylic Acids by the Hydrolysis of Nitriles 12.8: Conversion of carboxylic acids to alcohols using LiAlH4 Carboxylic acids can be converted to 1o alcohols using Lithium aluminum hydride (LiAlH4). Note that NaBH4 is not strong enough to convert carboxylic acids or esters to alcohols. An aldehyde is produced as an intermediate during this reaction, but it cannot be isolated because it is more reactive than the original carboxylic acid.