54023-32-4

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• 86577-00-6 3-(2-Phenyl-propylidene)-pentane-2,4-dione 
• 123-54-6 acetylacetone 
• 98-83-9 isopropenylbenzene 
• 34713-70-7 2-Phenylpropanal 

Relevant academic research and scientific papers

A facile synthesis of dihydrofurans utilizing silver(I)/celite promoted oxidative cycloaddition of 1,3-dicarbonyl compounds to alkenes

An efficient synthesis of dihydrofurans has been carried out starting from 1,3-dicarbonyl compounds.

Can-mediated oxidative free radical reactions in an ionic liquid

Cerium(IV) ammonium nitrate-mediated oxidative radical reactions are carried out in the presence of ionic liquids, including 1-butyl-3-methylimidazolium tetrafluoroborate, for the first time. The presence of the ionic liquid not only increases the rate and yield of reactions in dichloromethane but also extends the range of 1,3-dicarbonyl precursors, which can be utilized in these carbon-carbon bond-forming reactions.

Electronic and Steric Effects in the Addition of Electrophilic 1,3-Dicarbonylalkyl Radicals to Styrenes

The addition reactions of 1,3-dicarbonylalkyl radicals to ring-substituted styrenes have been kinetically investigated in MeOH and/or MeCN.It has been observed that the rate effect of ring substituents is nearly identical in the reactions of MeCOCHCOMe (1), MeOCOCHCOMe (2) and MeOCOCHCOOMe (4), the ρ value, in MeOH being -0.96, -1.01 and -1.06, respectively.Since the three radicals are relatively strong oxidants and have similar reduction potentials, an important contribution of the transfer structure RCOCHCOR(1-)*CH2CHAr(1+) to the addition transition state is suggested.It has also be found that in the reactions of 1 and 4 with α-alkyl-substituted styrenes the rate of additions is strongly influenced by the nature of the alkyl group, decreasing in the order: Me > Et > i-Pr > t-Bu.The observed effects are much larger than those reported for the corresponding reactions of the nucleophilic cyclohexyl radical.It is suggested that the α-alkyl substituents exert an effect of steric inhibition of resonance thereby ring delocalization of the charge and/or unpaired electron in the transition state is significantly reduced.Delocalization may be more important in the reactions of 1 and 4 than in those of the cyclohexyl radical since it is possible that the former utilizes a transition state occurring later along the reaction coordinate and/or characterized by a larger extent of charge transfer.

Oxidative Addition of 1,3-Dicarbonyl Compounds to Conjugated Olefins

A convenient one step synthesis of the 5-aryl- or 5-(1-alkenyl)-4,5-dihydrofurans from 1,3-dicarbonyl compounds and conjugated olefins in the presence of copper(II) chloride/pyridine or copper(II) chloride/pyridine/oxygen is reported.

The Facile Synthesis of Dihydrofurans by the Oxidation of Olefins with Tris(2,4-pentanedionato)manganese(III)

Eleven olefins were oxidized with tris(2,4-pentanedionato)manganese(III) at the reflux temperature to give the corresponding 3-acetyl-2-methyl-4,5-dihydrofurans in good yields.The oxidation of 9-benzylidene-9,10-dihydroanthracene under the same reaction conditions did not produce the corresponding dihydrofuran, but 9--9,10-dihydroxyanthracene.When 1,1-diphenylethene was oxidized at room temperature, 3-acetyl-2-hydroperoxy-2-methyl-5,5-diphenyltetrahydrofuran was obtained in a high yield.The effects of the solvent and the additives on the yield of dihydrofuran, the comparable reactivities of other (2,4-pentanedionato)metal complexes, such as Co(III), Cr(III), Fe(III), and Cu(II), and the reaction mechanism are discussed.

ACID CATALIZED RING CLOSURE REACTINOS OF ELECTROPHILIC ALKENES

Treatment of α-acyl-α,β-unsaturated ketones with sulfuric acid or dimethylformamide-hydrogen chloride or p-toluenesulfonic acid gave rise to 3-acyl-2-alkyl-4,5-dihydrofurans.Similar cyclization of α-acyl-α,β-unsaturated esters initially afforded 3-alkoxycarbonyl-2-alkyl-4,5-dihydrofurans which were transformed into 2-acylbutanolides on further reaction with sulfuric acid.This acid catalized cyclization is strongly dependent upon the substitution pattern of the electrophilic alkenes, the acid used and reaction conditions.