Luche Reduction-百灵威

The quick (5-10 min) 1,2-reduction of enones to corresponding allylic alcohols with CeCl₃•7H₂O/NaBH₄ in methanol is known as the Luche reduction. Ethanol and isopropanol may also be used, but reaction rates are slower. Formation of alkoxyborohydrides occur first followed by hydride attack of the carbonyl compound. This reaction is especially useful because many functional groups are tolerated, steric hindrance has little or no effect on regioselectivity, and ketones can be selectively reduced in the presence of aldehydes.

Reagents: CeCl₃•7H₂O, NaBH₄, Solvent (Methanol, Ethanol, Isopropanol)
Reactant: Acyclic or Cyclic α,β-Unsaturated Ketone
Product: Acyclic or Cyclic Allylic Alcohol (1,2 Reduction Product)
Type of Reaction: Reduction

Mechanism

Original Paper

Luche, J. L. Lanthanides in Organic Chemistry. 1. Selective 1,2 Reductions of Conjugated Ketones. J. Am. Chem. Soc. 1978, 100 (7), 2226–2227.

Top Citations

Highly Stereoselective Luche Reduction of α-Enonesulfoxides to 2-Sulfinyl Allylic Alcohols. Tetrahedron: Asymmetry 2007, 18 (11), 1269–1271.

Stereoselectivity of Sodium Borohydride Reduction of Saturated Steroidal Ketones Utilizing Conditions of Luche Reduction. Steroids 2010, 75 (19), 721–725.

The Stereoselective Horner-Wittig Reaction with Phosphine Oxides: Synthesis of Hindered z Alkenes via Luche Reduction. Tetrahedron Letters 1995,36 (43), 7905–7908.

Related Compounds

Sodium Borohydride (CAS 16940-66-2)

Cesium Chloride (CAS 18618-55-8)

Methanol (CAS 67-56-1)