γ,δ-Unsaturated β-Diketones by Acylation of Ketones

Abstract

[reaction: see text] Gamma,delta-unsaturated beta-diketones have been prepared by the acylation of ketones with N-acylbenzotriazoles of various aliphatic and aromatic alpha,beta-unsaturated carboxylic acids.

Reductive Reformatsky–Honda Reaction of α,β‐Unsaturated Esters: Facile Formation of 1,3‐Dicarbonyl Compounds and β‐Hydroxy Esters

“…[1] However, surprisingly, there is only a limited number of procedures for a direct synthesis of 1,3-dicarbonyl compounds, especially 1,3-diketones, this is due to the higher acidity of the a-hydrogen of the 1,3-dicarbonyl compounds than that of the starting carbonyl compounds. [2][3][4] We recently reported the direct synthesis of 1,3-diketones (3) by using Rh-catalyzed reductive a-acylation of a,b-unsaturated ketones (2) (Scheme 1). [5] The acylation proceeded at the a-position of the a,b-unsaturated ketones, since the Rh À H complex that was easily derived from the combination of RhClA C H T U N G T R E N N U N G (PPh 3 ) 3 with Et 2 Zn properly acted as the key intermediate.…”

1,3-Diketones. Synthesis and properties

“…N-Acylbenzotriazoles 13a-13e derived from aliphatic and aromatic α,β-unsaturated carboxylic acids were used to acylate ketones 14a-14f [22] in THF at -78°C in the presence of LDA. As a result, 16 α,β-unsaturated diketones 15-18 were obtained.…”

Facile and Highly Regiospecific Synthesis of 2-Aryl-Substituted Pyrazolidin-3-ones from α,β-Unsaturated N-Acylbenzotriazoles and Arylhydrazines

“…Calcd for C 17 H 18 N 2 O 2 : C, 72.32; H, 6.43;N,9.92. Found: C,72.21;H,6.47;N,9.89. 1, 137.6, 129.1, 128.7, 119.4, 51.1, 42.6, 18.5. …”