Luche reduction is the selective organic reduction of α,β-unsaturated ketones to allylic alcohols.[1][2][3] The active reductant is described as "cerium borohydride", which is generated in situ from NaBH4 and CeCl3(H2O)7.[4]
The Luche reduction can be conducted chemoselectively toward ketone in the presence of aldehydes or towards α,β-unsaturated ketones in the presence of a non-conjugated ketone.[5]
An enone forms an allylic alcohol in a 1,2-addition, and the competing conjugate 1,4-addition is suppressed.
The selectivity can be explained in terms of the HSAB theory: carbonyl groups require hard nucleophiles for 1,2-addition. The hardness of the borohydride is increased by replacing hydride groups with alkoxide groups, a reaction catalyzed by the cerium salt by increasing the electrophilicity of the carbonyl group. This is selective for ketones because they are more Lewis basic.
In one application, a ketone is selectively reduced in the presence of an aldehyde. Actually, in the presence of methanol as solvent, the aldehyde forms a methoxy acetal that is inactive in the reducing conditions.
^Kürti, László; Czakó, Barbara (2005). Strategic Applications of Named Reactions in Organic Synthesis: Background and Detailed Mechanisms. Elsevier Academic Press. ISBN 0-12-429785-4.
^Luche, J.-L. (1978). "Lanthanides in Organic Chemistry. 1. Selective 1,2 Reductions of Conjugated Ketones". J. Am. Chem. Soc.100 (7): 2226–2227. doi:10.1021/ja00475a040.
^Luche, J.-L.; Rodriguez-Hahn, L.; Crabbé, P. (1978). "Reduction of Natural Enones in the Presence of Cerium Trichloride". J. Chem. Soc., Chem. Commun. (14): 601–602. doi:10.1039/C39780000601.
^Paquette, Leo A.; Sabitha, G.; Yadav, J. S.; Scheuermann, Angelique M.; Merchant, Rohan R. (2021). "Cerium(III) Chloride". Encyclopedia of Reagents for Organic Synthesis. pp. 1–15. doi:10.1002/047084289X.rc041.pub3. ISBN 9780471936237.
^Gemal, A. L.; Luche, J.-L. (1981). "Lanthanoids in Organic Synthesis. 6. The Reduction of α-Enones by Sodium Borohydride in the Presence of Lanthanoid Chlorides: Synthetic and Mechanistic Aspects". J. Am. Chem. Soc.103 (18): 5454–5459. doi:10.1021/ja00408a029.
Luchereduction is the selective organic reduction of α,β-unsaturated ketones to allylic alcohols. The active reductant is described as "cerium borohydride"...
perform specifically conjugate reduction. To selectively form the allyl alcohol and avoid the 1,4 product, the Luchereduction uses "cerium borohydride" generated...
the selectivity for 1,2-reduction of unsaturated ketones (Luchereduction). α,β-Unsaturated esters also undergo 1,4-reduction in the presence of NaBH4...
borohydride and CeCl3 (Luchereduction) is also effective. Hydrazine and potassium hydroxide give limonene (6) via a Wolff–Kishner reduction. Oxidation of carvone...
groups, which can be used to direct reactivity. A famous example is the LucheReduction, where an oxophilic metal makes the carbonyl of a conjugated ketone...
enones is another route. Some of these methods are achieved by the Luchereduction, Wharton reaction, and the Mislow-Evans rearrangement. Allyl alcohol...
diazomethane insertion reaction dehydrohalogenation reaction with DMF Luchereduction to alcohol with sodium borohydride elimination reaction with Burgess...
the total synthesis of roseophilin, a potent antitumor antibiotic. Luchereduction Berger, Tassilo; Lebon, Jakob; Maichle‐Mössmer, Cäcilia; Anwander,...
isomigrastatin, reagent 11 and 15 need to be prepared. Through LACDAC reaction, Luchereduction, aqueous Ferrier rearrangement and Epoxidation, reagent 6, 7, 8, 9...
maintain U.S. distribution rights (including the family sitcom La Familia P. Luche and the sketch comedies La Hora Pico, Desmadruga2 and its spin-off Estrella2)...
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