ChemInform Abstract: REACTION OF 2‐ACETYL‐2‐CYCLOALKEN‐1‐ONES WITH CYCLIC β‐DIKETONES

Abstract

Reduktion der Cyclohexenone (I) mit Zn, das durch AgOAc aktiviert wurde, ergibt als Hauptprodukte die Cyclohexadienole (II), deren Reaktionsverhalten gegenüber den β‐Diketonen (III) mit aktiver Methylengruppe unter den Bedingungen der Michael‐Reaktion untersucht wird.

Chemistry of 2-Acylcycloalkane-1,3-diones

“…Under the action of sodium borohydride they have been transformed into chlorovinyl diols ( 103 ), which in turn have been reduced to diols ( 104 ) by sodium in liquid ammonia (Scheme ) . Reduction by zinc activated by silver acetate provides a method for the conversion of chlorides ( 96 ) to diones ( 105 ), which easily isomerize into keto dienols ( 106 ) (Scheme ) 20

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“…Cyclic dithioacetals (67) can be thionated to give thia derivatives (69) with Lawesson's reagent and other dithiadiphosphetane disulfides. 53 Under these conditions acyclic dithioacetals (68) readily undergo dealkylation (dearylation) followed by intramolecular condensation to give the 1,2dithiol-3-thione (70). The reaction of the dimethyl derivative (68) with P 4 S 10 -Et 3 N in acetonitrile at -30 °C has permitted isolation of the primary dealkylation product: dimedonedithiocarboxylate (71).…”

Synthesis of Tri- and Tetracycle Compounds via Reaction of 1,3-Decalinediones and 4-Hydroxycoumarines with 2-Acetyl-2-Cyclohexenes and Biological Testing

“…4-Hydroxycoumarins (13a, b) were obtained from phenols or resorcinol as it is descried in [23]. Using 2-acetylcy-clohexen-1,3-dions as starting materials acetylcyclohexadienols (4b, c) were prepared in accordance with our method [12] previously described.…”

“…Evaporation of the solvent yielded: 12-Methyl-6,11-dioxa-9-hydroxy-D-homo-l,3,5(10)-tetraen-7,17a-dione (15). To a solution of 1.62 g (10 mmole) 4-hydroxycoumarin (13a) in 60 ml chloroform was added 1.38 g (10 mmole) freshly-prepared [12] acetylcyclohexadienol (4b) in 150 ml ether and the mixture held at + 10˚C for 24 h. The solvent was evaporated and the residue separated on a chromatograph column (silicagel 100/160 m, l6 cm, ethyl acetate). The yield was 2.4 g (80%) hydroxydiketone 15 and 0.12 g (9%) of the dimer [13] (11a, b and 16a, b,…”

“…We have developed an efficient two-step synthesis of ketodienols (4b, c) [12] from corresponding 2-acetylcyclohexan-1,3-diones, which allowed them to explore their chemical properties. It has been shown that in the presence of bases, they can easily enter the reaction with 1,3-cyclohexanediones giving adducts of Michael addition (6a, b, c).…”