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-While 1,4-reduction usually predominates in the reduction of α,β-unsaturated ketones with NaBH4 alone, selective 1,2-reduction is possible using CeCl3-7H2O as an additive. Luche reduction can be used for a wide range of compounds and reaction times are also short (3-5 min). Simple procedure is another plus for this reaction. DIBAL is used for the same purpose but it requires lower temperature.
Aside from acting as a hard Lewis acid, cerium is considered to promote ligand exchange on the boron atom leading to the formation of NaHnB(OMe)4-n, a harder reducing agent than NaBH4.
In the substrate containing both ketone and aldehyde groups, Ce(III)-catalyzed acetalization (or hemiacetalization or hydration) prevents the aldehyde from getting reduced, enabling selective reduction of the ketone.
An example in the synthesis of batracotoxinin.
 Kurosu, M.; Marcin, L. R.; Grinsteiner, T. J.; Kishi, Y. J. Am. Chem. Soc. 1998, 120, 6627. doi: 10.1021/ja981258g