AlCl₃-Mediated Aldol Cyclocondensation of 1,6- and 1,7-Diones to Cyclopentene and Cyclohexene Derivatives

Abstract

Exactly 1/3 mol of AlCl3 is sufficient to cyclize 1 mol of 1,ω-dibenzoylbutane (or pentane) to a cyclopentenone (or hexenone) derivative in high yield at room temperature in 40 min to several hours. This condensation is driven by removing elements of water as HCl and Al(OH)3, and the product enones are exclusively unconjugated, unlike the base-catalyzed condensations providing thermodynamically more stable conjugated enones.

AlCl3-Catalyzed Cascade Reactions of 1,2,3-Trimethoxybenzene and Adipoyl Chloride: Spectroscopic Investigations and Density Functional Theory Studies

“…In that reaction, they only obtained the demethylation product of both aryl methyl ethers in the ortho positions, and then they converted these OH groups to the methoxy groups with dimethyl sulfate . On the other hand, unconjugated enones were formed by acid-catalyzed aldol condensation of 1,4-dibenzoylbutane, also called 1,6-diphenylhexane-1,6-dione. ,, …”

Computational study on the Rh‐catalyzed CC activation of cyclopropanol to construct diketone or monoketone

“…As one of the important carbon synthons used to prepare pharmaceutically relevant and biologically active five‐ and six‐membered carbo‐ and heterocyclic compounds, [ 1–3 ] 1,6‐diketones and other acyclic long‐chain diketones have attracted increasing attention in recent years. Although several synthetic methods have been reported to yield 1,6‐diketones, many of them were less efficient and selective, and used nonreadily obtainable substrates and synthetically harsh reaction conditions.…”

Theoretical study on the Rh-catalyzed C−C activation of cyclopropanol to construct diketone or monoketone

“…As one of the important carbon synthons to prepare pharmaceutically relevant and biologically active fiveand six-membered carbo-and heterocyclic compounds, [1][2][3] 1,6-diketones and other acyclic long-chain diketones have attracted increasing attention in recent years. Although a lot of synthetic methods have been reported to yield 1,6-diketones, many of them were less efficiency and selectivity, and used non-readily obtainable substrates and synthetically harsh reaction conditions.…”