Synthesis of 1,5-diketones
An asymmetric direct Michael addition of α,β-unsaturated aldehydes with acetophenone catalyzed by a Jørgensen-Hayashi catalyst in methanol gave δ-keto aldehydes in up to 82% yield and 98% ee.
W. Li, W. Wu, J. Yang, X. Liang, J. Ye, Synthesis, 2011, 1085-1091.
An intermolecular Michael addition of simple aldehydes to nonactivated enones with high enantioselectivities is catalyzed by 5 mol-% diphenylprolinol methyl ether.
Y. Chi, S. H. Gellman, Org. Lett., 2005, 7, 4253-4256.