Clemmensen reduction

Clemmensen reduction
Named after Erik Christian Clemmensen
Reaction type Organic redox reaction
Reaction
Ketone or Aldehyde
+
Zn(Hg)
+
HCl
↓
Reduction product
Conditions
Catalyst
+Δ
Identifiers
Organic Chemistry Portal clemmensen-reduction
RSC ontology ID RXNO:0000038

Clemmensen reduction is a chemical reaction described as a reduction of ketones or aldehydes to alkanes using zinc amalgam and concentrated hydrochloric acid (HCl).[1][2] This reaction is named after Erik Christian Clemmensen, a Danish-American chemist.[3]

The Clemmensen reduction
Scheme 1: Reaction scheme of Clemmensen Reduction.

Clemmensen reduction conditions are particularly effective at reducing aryl[4]-alkyl ketones,[5][6] such as those formed in a Friedel-Crafts acylation. The two-step sequence of Friedel-Crafts acylation followed by Clemmensen reduction constitutes a classical strategy for the primary alkylation of arenes.  

  1. ^ Smith, Michael (2007). March's advanced organic chemistry : reactions, mechanisms, and structure. Jerry March (6th ed.). Hoboken, N.J.: Wiley-Interscience. p. 1835. ISBN 978-0-471-72091-1. OCLC 69020965.
  2. ^ Carey, Francis A.; Sundberg, Richard J. (2007). Advanced Organic Chemistry: Part B: Reactions and Synthesis (5th ed.). New York: Springer. p. 453. ISBN 978-0387683546.
  3. ^ Clemmensen, Erik (1913). "Reduktion von Ketonen und Aldehyden zu den entsprechenden Kohlenwasserstoffen unter Anwendung von amalgamiertem Zink und Salzsäure". Berichte der Deutschen Chemischen Gesellschaft. 46 (2): 1837–1843. doi:10.1002/cber.19130460292. ISSN 0365-9496.
  4. ^ Carey, Francis A.; Sundberg, Richard J. (2007). Advanced Organic Chemistry: Part B: Reactions and Synthesis (5th ed.). New York: Springer. p. 453. ISBN 978-0387683546.
  5. ^ "Y-Phenylbutyric Acid". Organic Syntheses. 15: 64. 1935. doi:10.15227/orgsyn.015.0064. ISSN 0078-6209.
  6. ^ "CREOSOL". Organic Syntheses. 33: 17. 1953. doi:10.15227/orgsyn.033.0017. ISSN 0078-6209.