A new approach to the synthesis of 16-heteroprostanoids via isoxazole intermediates

Translated from Khimiya Geterotsiklicheskikh Soedinenii. Vol. 30. No. 3, pp. 424–425, March, 1994.     

Synthesis of novel 2-perfluoroacylcyclohexane-1,3-diones

A one-pot synthesis of 2-perfluoroalkanoylcyclohexane-1,3-diones via C-acylation of cyclohexane-1,3-diones with N-perfluoroacylimidazole as an acylating agent is reported. A reaction was examined with isolated N-trifluoroacetylimidazole and with N-perfluoroacylimidazoles generated in situ from perfluorocarboxylic acid anhydrides or perfluorocarboxylic acids.     

Heterocyclic analogs of prostaglandins: III. Synthesis of 10-oxa-13-aza, 11-oxa-13-aza, and 9-oxa-7-aza prostanoids from 3-acyl-and 3-(3-arylprop-2-enoyl)furan-2,4-diones

A number of new 10-oxa-13-aza, 11-oxa-13-aza, and 9-oxa-7-aza prostanoids belonging to the B series were synthesized on the basis of 3-acyl-and 3-(3-arylprop-2-enoyl)furan-2,4(3H,5H)-diones. The scheme of synthesis includes selective hydrogenation of the exocyclic carbonyl group and reduction of the conjugated double bond in the acyl fragment of 3-acyl-and 3-(3-arylprop-2-enoyl)furan-2,4(3H,5H)-diones to obtain 3-alkyl-and 3-(3-arylpropyl)furan-2,4(3H,5H)-diones, transformation of the latter into the corresponding regioisomeric enol ethers via regioselective O-alkylation, and treatment of the enol ethers with primary aliphatic amines.     

Synthesis and properties of fluorinated 2-benzoylcyclohexane-1,3-diones

Fluorinated 2-benzoylcyclohexane-1,3-diones were obtained by the O-C isomerization of the corresponding 3-benzoyloxycyclohex-2-en-1-ones under the action of acetone cyanohydrin in the presence of triethylamine in the medium of absolute acetonitrile. The structure of the target compounds was investigated by the means of IR and NMR spectroscopy, and X-ray diffraction analysis.     

Chemical Transformations of 9,11-Ethano-13,15-isoxazolinoprostanoids

Chemical transformations of 9,11-ethano-13,15-isoxazolinoprostanoids furnished new prostanoids with a bufunctional fragment of -hydroxyketone and -aminoalcohol in the -chain. The reaction of -hydroxyketones with methanesulfonyl chloride gave rise to prostanoids with an enone component in the -chain. 9,11-Ethano-16-thiaprostanoids were prepared for the first time by nucleophilic addition of thiols to the polarized double bond in the -chain. The 1,3-dipolar addition to terminal alkenes of nitrile oxides generated from nitromethylene derivatives of bicycloheptane provided 9,11-ethano-13,15-isoxazolinoprostanoids with an alkyl, phenyl, or additional heterocyclic fragment in the -chain.     

Selective reduction of the acyl group in cyclic α-acyl-β-dicarbonyl compounds with sodium cyanoborohydride. Efficient synthesis of cyclic α-alkyl-β-dicarbonyl compounds

Efficient synthesis of cyclic -alkyl--dicarbonyl compounds of the cyclopentane, cyclohexane, tetronic acid, and -pyrone series from the corresponding cyclic -acyl--dicarbonyl compounds under the action of NaBH₃(CN) in a THF--HCl system is described.