Synthesis of 1,5-diketones
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.
A ruthenium-catalyzed alkylation of cyclopropanols with sulfoxonium ylides provides diverse 1,5-diketones with good efficiency and broad substrate scope. Preliminary mechanistic studies suggest that this process involves a sequential C-C activation and carbene migratory insertion.
X. Huang, J. Li, H. He, K. Yan, R. Lai, Y. Luo, M. Guan, Y. Wu, Synthesis, 2022, 54, 779-787.
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 alkyl intercepted Meyer-Schuster rearrangement with α,β-unsaturated ketones as the electrophiles conveniently provided 2-methylene-pentane-1,5-diones in high yields. An optional in situ Michael addition of malononitrile gives diverse 2-malononitrile methyl substituted pentane-1,5-diones.
Z. Wang, Y. Sun, Q. Zhang, W. Pan, T. Li, Y. Yin, J. Org. Chem., 2022, 87, 3329-3340.