Reaction Of Dimedone Research Articles

3-Hydr-oxy-5,5-dimethyl-2-(2-oxo-propyl)cyclo-hex-2-enone.

The title compound, C11H16O3, was obtained by reaction of dimedone, 5,5-dimethylcyclohexane-1,3-dione, and α-chloro­acetone. The cyclo­hexenone ring exhibits an envelope conformation with puckering amplitudes Q = 0.433 (2) and Φ = −109.0 (3)°. The 2-oxopropyl fragment is almost perpendicular to the cyclo­hexa­none ring [dihedral angle = 77.72 (8)°]. In the crystal, the mol­ecules are linked to each other through O—H⋯O hydrogen bonding, building a chain parallel to the b axis.

An Efficient Solvent Free Synthesis of 1,8‐Dioxo‐octahydroxanthene Using p‐Toluene Sulfonic Acid

AbstractA simple and efficient method for the synthesis of 1,8‐dioxo‐octahydroxanthene by using p‐toluenesulfonic acid as a catalyst under solvent free conditions is described, which involves cyclization of 2,2‐arylmethylenebis(3‐hydroxy‐5,5‐dimethyl‐2‐cyclohexene‐1‐one) that was obtained firstly by the reaction of dimedone with aromatic aldehydes in water as solvent and catalyst at room temperature. The experimental procedures in the two steps are very simple and the products are formed in excellent yields.

Single-Pot Synthesis of Spiroannulated Dihydrofurans by Iodine–Ammonium Acetate–Mediated Reaction of Dimedone with Aldehydes

Iodine–ammonium acetate–mediated annealation of dimedone with aldehydes led to facile formation of spirodihydrofuran in good yields through tandem Knoevenagel–Michael iodonation and cyclodehydroiodonation reactions in a single pot.

Synthesis of 2,2′-arylmethylene bis (3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) in aqueous medium at room temperature

The reaction of dimedone with various aromatic aldehydes produces 2,2′-arylmethylene bis (3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) in excellent yields. The reactions occur in water as solvent at room temperature and avoiding the addition of any catalyst. The workup procedure is very simple and the products do not required further purification.

9-(4-Fluoro-phen-yl)-3,3,6,6-tetra-methyl-10-p-tolyl-1,2,3,4,5,6,7,8,9,10-deca-hydroacridine-1,8-dione.

The title compound, C30H32FNO2, was synthesized by the reaction of dimedone with 4-fluoro­benzaldehyde and p-toluidine in water. The dihydro­pyridine and both of the cyclo­hexenone rings are not planar and have flattened boat conformations. The dihedral angle between the planar aromatic rings is 15.33 (3)°. In the crystal structure, inter­molecular C—H⋯O hydrogen bonds link the mol­ecules into centrosymmetric dimers.

10-(4-Chlorophenyl)-9-(4-methoxyphenyl)-3,3,6,6-tetramethyl-3,4,6,7-tetrahydroacridine-1,8(2H,5H,9H,10H)-dione

The title compound, C30H32ClNO3, was synthesized by the reaction of dimedone with 4-methoxy­benzaldehyde and 4-chloro­benzenamine in water. The dihydro­pyridine ring is in a boat conformation. Both cyclo­hexene rings adopt envelope conformations. The chloro­phenyl and methoxy­phenyl rings form dihedral angles of 81.31 (11) and 88.84 (12)°, respectively, with the planar part of the dihydro­pyridine ring. The crystal packing is stabilized by weak C—H⋯O hydrogen bonds.

9-(1,3-Benzodioxol-5-yl)-10-(4-chlorophenyl)-3,3,6,6-tetramethyl-3,4,6,7-tetrahydroacridine-1,8(2H,5H,9H,10H)-dione

The title compound, C30H30ClNO4, was synthesized by the reaction of dimedone with 1,3-benzodioxole-5-carbaldehyde and 4-chloro­benzenamine in water. The dihydro­pyridine ring adopts a boat conformation, while the two cyclo­hexenone rings have envelope conformations.

9-(1,3-Benzodioxol-5-yl)-3,3,6,6-tetramethyl-10-p-tolyl-3,4,6,7-tetrahydroacridine-1,8(2H,5H,9H,10H)-dione

The title compound, C31H33NO4, was synthesized by the reaction of dimedone with 1,3-benzodioxole-5-carbaldehyde and p-toluidine in water. The dihydro­pyridine and both of the cyclo­hexenone rings are not planar and have flattened boat conformations, while the remaining rings are planar. The dihedral angle between the planar rings of the 1,3-benzodioxole system is 1.30 (2)°, so they are nearly coplanar; the angle between the benzene and benzodioxole rings is 9.7 (1)°.

9-(4-Chlorophenyl)-3,3,6,6-tetramethyl-1,8-dioxo-1,2,3,4,5,6,7,8,9,10-decahydroacridine-10-acetic acid

The title compound, C25H28ClNO4, was synthesized by the reaction of dimedone with 4-chloro­benzaldehyde and glycine in glycol under microwave irradition. X-ray analysis reveals that the dihydro­pyridine ring is in a boat conformation and both cyclo­hexenone rings adopt envelope conformations.

Uses of 5,5-Dimethyl-7-oxocyclohexeno[b]thiophene Derivatives in Heterocyclic Synthesis

The reaction of dimedone (1) with sulfur and the cyanomethylene reagents gave the cyclohexeno[b]thiophene derivatives. The reactivity of the latter products towards some chemical reagents was studied to give annulated derivatives. Their toxicity also was studied.

Enantioselective Enol Lactone Synthesis under Double Catalytic Conditions.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Enantioselective Enol Lactone Synthesis under Double Catalytic Conditions

[reaction: see text] The reaction of dimedone with 1-(2-alkenoyl)-4-bromo-3,5-dimethylpyrazoles in THF, catalyzed by catalytic amounts of both DBFOX/Ph-nickel(II) perchlorate trihydrate and 2,2,6,6-tetramethylpiperidine, in the presence of acetic anhydride in THF produces the corresponding enol lactones in high enantioselectivities through enantioselective Michael additions followed by cyclization with removal of the pyrazole auxiliary. Other related nucleophile precursors can be successfully applied in the enantioselective enol lactone synthesis under the double catalytic conditions.

10-Cyclopropyl-9-(4-hydroxy-3-methoxyphenyl)-3,3,6,6-tetramethyl-1,2,3,4,5,6,7,8,9,10-decahydroacridine-1,8-dione

The title compound, C27H33NO4, was synthesized by the reaction of dimedone with 3-methoxy-4-hydroxy­benz­aldehyde, cyclo­propyl­amium chloride and NaOAc in glycol and water. X-ray analysis reveals that the di­hydro­pyridine ring is in a distorted boat conformation. O—H⋯O hydrogen bonds involving the hydroxy and carbonyl O atoms link the screw-related mol­ecules into zigzag chains along the b axis.

9-[4-(1,2,3,4,5,6,7,8,9,10-Decahydro-3,3,6,6-tetramethyl-1,8-dioxoacridin-9-yl)phenyl]-1,2,3,4,5,6,7,8,9,10-decahydro-3,3,6,6-tetramethylacridine-1,8-dione dihydrate

The title compound, C40H48N2O4·2H2O, was synthesized by the reaction of dimedone with terephthal­aldehyde and NH4OAc in glycol. X-ray analysis reveals that the di­hydro­pyridine and cyclo­hexenone rings adopt half-boat conformations. The screw-related mol­ecules form N—H⋯N and O—H⋯O hydrogen-bonded chains along the c axis.

9-(4-Hydroxy-3-methyoxyphenyl)-3,3,6,6,10-pentamethyl-1,2,3,4,5,6,7,8,9,10-decahydroacridine-1,8-dione

The title compound, C25H31NO4, was synthesized by the reaction of dimedone with 4-hydroxy-3-methoxy­benz­aldehyde and CH3NH2HCl(NaOAc) in glycol. X-ray analysis reveals that the dihydropyridine ring is in a distorted-boat conformation. O—H⋯O hydrogen bonds involving the hydroxy and carbonyl O atoms link glide-related mol­ecules into zigzag chains along the c axis.

Triphenylphosphine Catalized Reaction Between 1,3-Dicarbonyl Compounds and Acetylenic Esters

Reaction of triphenylphosphine with dialkyl acetylenedicarboxylates in the presence of strong CH-acids such as acetylacetone, methyl acetoacetate, cyclopentane-1,3-dione, or 5,5-dimethylcyclohexane-1,3-dione (dimedone) have been studied. In some cases, stable phosphorus ylides are obtained in excellent yields. The ylide moiety of these compounds is strongly conjugated with the adjacent carbonyl group and rotation about the partial double bond in (E) and (Z) geometrical isomers is slow on the NMR time scale at ambient temperature. Thus, these ylides exist as a mixture of geometrical isomers. From the reaction of dimedone with dimethyl acetylenedicarboxylate (DMAD) in the presence of triphenylphosphine, a chromene derivative is obtained. A Michael addition product was obtained from the reaction of cyclopentane-1,3-dione and DMAD.

Two diastereomers of 9-(2,6-dichlorophenyl)-4a-hydroxy-3,3,6,6-tetramethyl-1,2,3,4,4a,5,6,7,8,9a-decahydroxanthene-1,8-dione in the same crystal.

The reaction of dimedone with 2,6-dichlorobenzaldehyde leads to the title compound, C(23)H(26)Cl(2)O(4). In principle, the reaction could yield eight different stereoisomers. We have found four of them in the same crystal as two enantiomeric pairs of diastereomers, which means that the asymmetric unit is built up of two different diastereomers. Two of the three chiral centres display the same configuration, while the third is different in the two molecules in the asymmetric unit. The packing of the molecules is stabilized by hydrogen bonds between the hydroxy group and the carbonyl group attached to the cyclohexene ring, forming chains in which the different diastereomers alternate.

Cyclocondensation and Aromatization During Reaction of Dimedone, p-Dimethylaminobenzaldehyde, and Ammonium Acetate

Cyclocondensation and Aromatization During Reaction of Dimedone, p-Dimethylaminobenzaldehyde, and Ammonium Acetate

Synthesis of pyridine derivatives by the three-component condensation of a β-dicarbonyl compound, β-enaminocarbonyl compound, and ethyl orthoformate

The major products of the three-component condensation of a β-dicarbonyl compound, β-enaminocarbonyl compound, and ethyl orthoformate are pyridine derivatives. The reaction of 1,3-cyclohexanedione or dimedone, the enamino ketones obtained from these diones, and ethyl orthoformate gives octahydroacridinediones, while the reaction of dimedone, ethyl β-aminocrotonate, and ethyl orthoformate gives a tetrahydroquinoline derivative. The structures of the minor products were established in some cases. The reduction of 3,3,6,6-tetramethyl-1,2,3,4,5,6,7,8-octahydro-1,8-acridinedione by LiAlH4 proceeds with retention of the pyridine ring and leads to the corresponding octahydroacridinediol.

Alkylation of β-dicarbonyl compounds with 1,2-dibromocyclohexane

Alkylation of acetylacetone, ethyl acetoacetate, and diethyl malonate with 1,2-dibromocyclohexane in the presence of K2CO3 in DMSO occurs only asC-alkylation accompanied by dehydrobromination, whereas a similar reaction of dimedone follows bothC- andO-alkylation pathways.