Carboxylic Acid and Derivatives

• RCOOH is the most abundant organic compound present in biological systems as they take on diverse roles in the biological processes
• RCOOH serves as a parent compound for a variety of derivatives
• RCOOH are found almost everywhere in nature (eg. acetic acid = vinegar, butanoic acid = rancid odor of butter, hexanoic acid = dirty socks)
• RCOOR' are abundant in nature and is responsible of fragrant odors of fruits and flowers. It is also used as solvents and plasticizers.
• RCONH2 are abundant in living organisms. Least reactive of all derivative but very stable in normal living conditions.
• RCOX and RCO2COR' are not found in nature because both are very reactive
• RCOSR' and RCO2PO32- are biological acid derivatives and are reaction substrates in living organisms
• Synthesis of Carboxylic Acids

  • Oxidation of alkyl benzene
  • Oxidation of Primary Alcohol and Aldehyde
  • SN2 reaction of RX with RCN followed by RCN hydrolysis
• Reactions of Carboxylic acids and Derivatives

  • Nucleophilic Acyl Substitution Reactions
• Nucleophilic Acyl Substitution

  • RCOOH and its derivative compounds are generally made of an acyl group with a good leaving group attached to the carbonyl carbon
  • this allows the carbonyl group to participate in nucleophilic acyl substitution reaction
  • derivative species have different reactivity and more reactive ones are used to synthesize the less reactive derivatives
  • From most unreactive to most reactive : RCNH2 < RCOOR' < RCSR' < RCO2COR' < RCOX
• Carboxylic Acids

  • Acid Halide (Acid Chloride) = SOCl2
  • Esters = ROH, HCl
  • Amides = NH3/ RNH2/ R2NH, DCC
  • Aldehyde (partial) and Primary Alcohol (complete) = LiAlH4, H3O+
  • Acid Anhydride = Acid Halide
• Acid Halides or Acid Anhydrides

  • Carboxylic Acid = H2O
  • Esters = ROH, Pyridine (applicable to Acid Halide only)
  • Amides = NH3/RNH2/R2NH (2 moles if its Acid Halide)
  • Ketones (partial) and Tertiary Alcohol (complete) = 2 RMgX, H3O+
  • Aldehydes (partial) and Primary Alcohol (complete) = LiAlH4, H3O+
• Esters

  • Carboxylic Acid = H2O
  • Amides = NH3/RNH2/R2NH
  • Ketones (partial) and Tertiary Alcohol (complete) = 2RMgX, H3O+
  • Aldehyde (partial) and Primary Alcohol (complete) = LiAlH4, H3O+
• Amides

  • Carboxylic Acid = H2O
  • Amines = LiAlH4, H3O+
• Nitriles

  • Carboxylic Acid = H2O, NaOH or H3O+
  • Ketones = RMgX, H3O+
  • Aldehyde - LiAlH4, H3O+