Carbonyl Compound Crash Course

Aldehydes and Ketones: Nomenclature, Synthesis, and Reactions

• Aldehydes and ketones are characterized by the carbonyl functional group (C=O).
• Carbonyl compounds are abundant in nature and have many important applications in industry, biology, and pharmaceuticals.
• The C=O bond is planar, shorter, stronger, and more polar than the C=C bond in alkenes. Carbon is electrophilic and oxygen is nucleophilic.
• Carbonyl compounds can be categorized into two groups: aldehydes and ketones (R-C=O is bonded to H or C) and carboxylic acids and their derivatives.
• Aldehydes are named by selecting the longest carbon chain containing the -CHO group and replacing the terminal -e of the corresponding alkane with -al.
• Ketones are named by selecting the longest carbon chain containing the -C=O group and replacing the terminal -e of the corresponding alkane with -one.
• Aldehydes and ketones can also be named using common names.
• The R-C=O group can be used as a substituent, with the suffix -yl, and the prefix oxo- is used if other functional groups are present.
• Aldehydes can be synthesized by oxidizing primary alcohols using pyridinium chlorochromate (PCC).
• Ketones can be synthesized by oxidizing secondary alcohols using PCC, CRO3, or Na2Cr2O7 or by hydrating terminal alkynes in the presence of Hg+2 as a catalyst.
• Aromatic ketones can be synthesized through Friedel-Crafts acylation of an aromatic ring.
• Aldehydes can be oxidized to carboxylic acids using Tollens' reagent, which involves the use of silver ions in aqueous ammonia. Ketones are unreactive towards this reaction. Aldehydes and ketones can also be reduced using strong nucleophiles such as NaBH4 and LiAlH4.