Benzoin & Perkin
Condensation
Contents
• Benzoin condensation
• Perkin condensation
Learning
Objectives
At the end of this
lecture, student will be able to
• Explain the mechanism involved in benzoin and Perkin
condensation
Benzoin
Condensation
• Self condensation of aromatic aldehydes in the presence of
CN‾ as catalyst
• Aqueous ethanolic NaCN or KCN
• Product – α hydroxy ketone
Mechanism of Benzoin Condensation
Perkin
Condensation
• Condensation reaction between aromatic aldehyde and
aliphatic anhydride
• Catalyst – Na or K salt of the same acid
• Product – α,β – unsaturated acids
Mechanism of
Knoevenagel
Condensation
• Condensation of an aldehyde or a ketone that has no α
hydrogens and a compound with active methylene group
Summary
• Benzoin condensation – self condensation of aromatic
aldehydes in the presence of CN‾ as catalyst
• Product – α hydroxy ketone
• Perkin condensation – reaction between aromatic aldehyde and aliphatic
anhydride with Na or K salt of the same acid as catalyst
• Product – α,β – unsaturated acids