M 10- Carbonyl Compounds

• Carbonyl compounds


  Chemicals that include a carbon-oxygen double bond
• Carbonyl group


  • Polarity is stronger than molecules having carbon atoms connected to oxygen through a single bond
• Carbonyl compounds


  • Polar in nature, exhibit both positive and negative charges in slight form
  • Chemically reactive, undergo nucleophilic addition and substitution reactions
  • Insoluble in water but sometimes they dissolve other forms of polar molecules
• Ketones


  • Carbonyl compounds that contain a carbonyl group bonded to two alkyl or aryl groups
  • Important intermediates in drug synthesis and commonly used to modify the properties of drugs

  
• Aldehydes


  • Carbonyl compounds that contain a carbonyl group bonded to at least one hydrogen atom and one alkyl or aryl group
  • Important intermediates in drug synthesis and commonly used as reagents in organic chemistry

  
• Carboxylic acids


  • Carbonyl compounds that contain a carbonyl group bonded to a hydroxyl group and an alkyl or aryl group
  • Important in drug design because they can form esters and amides, which are common functional groups in drugs

  
• Esters


  • Carbonyl compounds that contain a carbonyl group bonded to an oxygen atom and an alkyl or aryl group
  • Important in drug design because they are stable and can easily be hydrolyzed to form carboxylic acids and alcohols
• Amides


  • Carbonyl compounds that contain a carbonyl group bonded to a nitrogen atom and an alkyl or aryl group
  • Important in drug design because they are stable and can easily be hydrolyzed to form carboxylic acids and amines

  
• Addition reactions of carbonyl compounds

  1. Base-catalyzed addition (under basic or neutral conditions)

  2. Acid-catalyzed addition (under acidic conditions)
• Carbonyl alkylation


  Process in which the carbonyl compounds are alkylated with the use of organometallic compounds like Grignard reagents, organolithium reagents, acetylides, etc.
• Carbonyl reduction


  Process in which the carbonyl groups are reduced by the hydride reagents such as the LiAlH4 and NaBH4 with baker's yeast or by the process of catalytic hydrogenation
• Addition of water to aldehydes

  Formation of a hydrate via a nucleophilic addition mechanism
• Carbonyl substitution reaction


  1. The carbonyl serves as the electrophile and 'X' is a leaving group, which is replaced by the 'Nu' group

  2. Substitution of the atom of a hydrogen by an electrophile
• Ketones usually do not form stable hydrates
• Addition of water to carbonyl compounds

  1. Water, acting as nucleophile, is attracted to the partially positive carbon of the carbonyl group that generates an oxonium ion

  2. The oxonium ion liberates a hydrogen ion that is picked up by the oxygen anion in an acid-base reaction
• Addition of alcohol to aldehydes


  1. Produces either hemiacetals (one -OH group and one -OR group bonded to the same carbon) or acetals (two -OR groups bonded to the same carbon), depending upon conditions

  2. Hemiacetal is produced when the two reactants are mixed together, acetal is produced when the two reactants with hydrochloric acid are mixed