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 Perkin Condensation

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