Investigation of furan acetal compounds

New 1,3-dioxanes, which are derivatives of 2-nitro-2-ethylpropane-1,3-diol and aldehydes of the furan series, were synthesized. The nitrodioxanes were reduced by means of sodium amalgam to the corresponding amines. The kinetics of the formation of the nitrodioxanes was studied. The accelerating action of the electron-acceptor diol substituent on the reaction rate was established. The rate constants in the aldehyde series increase on passing from-methylfurfural to-nitrofurfural, and they correlate satisfactorily with Brown's _p ⁺ constants.See [1] for communication IV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1159–1162, September, 1972     

Reaction of carbonyl compounds with dimethyl 3-ketoglutarate. Synthesis of bicyclic furan derivatives

Acid catalyzed reaction of cyelododecane-1,2-dione VI with dimethyl,3-ketoglutarate II led to the formation of methyl (E)-6,7,8,9,10,11,12,13-octahydro-3-(methoxycarbonyl)cyclododeca-[b]furan-2-aeetate IX, presumably formed through the dihydrodihydroxy furan VIII. This dihydrofuran intermediate VIII was shown to be characteristic of the reaction of 2-substituted carbonyl-compounds with 11 for both α-chlorocyclohexanone and α-chlorocyclopentanone furnished furans XVIa and XX, respectively, when treated with 11. The effect of dihydrodihydroxy-furan intermediates on the course of such reactions is discussed.     

Phase-transfer catalyzed alkoxylation of 2-(dichloromethyl) furan by alcohols in the presence of potassium hydroxide

Reaction of 2-(dichloromethyl)furan (I) with KOH in a CH₂Cl₂ medium and in the presence of alcohols (methanol, ethanol, and n-butanol) and a catalytic amount of triethylbenzylammonium chloride (TEBAC) results in the formation of 2-chloro-methylene-5-alkoxy-2, 5-dihydrofurans (II) (mixtures of Z- and E-isomers) and 2-dialkoxymethylfurans (III), in overall yields of up to 96%. Reaction with isopropyl and tert-butyl alcohols gave only the corresponding products (II), in 21 and 12% yield, respectively.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1403–1407, June, 1991.     

Organosilicon compounds of the furan series VIII. Reaction of triethylsilane with unsaturated alcohols

When triethylsilane is reacted with unsaturated primary alcohols such as allyl, cinnamic, and furylallyl alcohols, in the presence of H₂PtCl₆, the main reaction is one of dehydrocondensation. With secondary unsaturated alcohols such as methylallylcarbinol and furylallylcarbinol, dehydrocondensation and hydrosilylation take place simultaneously. A number of new furylalkoxy- and furyl-alkenoxysilanes are synthesized and described.     

Study of furan compounds

Adducts of 2,5-dimethoxy-2,5-dihydrofuran with several dienes were obtained by the Diels-Alder reaction. The possibility of the participation of 2-methoxy-7-methyl-1,6-dioxaspiro-[4.4]-3-nonene as a dienophile in the diene synthesis was demonstrated for the first time. The structures of the adducts were confirmed by their IR spectra and catalytic hydrogenation.See [8] for Communication XLVI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1591–1594, December, 1970.     

Study of furan compounds

The electrolytic alkoxylation of several furan aldehydes and ketones was accomplished. It is shown that the electrolytic methoxylation of the aldehydes is an intramolecular reaction and leads to compounds of the 2,7-dimethoxy-1,6-dioxaspiro[4.4]-3-nonene series. Depending on the conditions, 2,7-dimethoxy-1,6-dioxaspiro[4.4]nonanes and 1,6-dioxaspiro [4.4]-nonanes were synthesized by the catalytic hydrogenation of the latter. The corresponding -carbonyl-containing 2,5-dimethoxy-2,5-dihydrofurans are formed in the case of the methoxylation of the furan ketones.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1155–1158, September, 1971.     

Organosilicon compounds of the furan series. VI. Nitrogen- and sulfur-containing organosilicon derivatives of furan

Five new furfurylaminoorganylsilanes and furfurylaminoalkyltriorganylsilanes are synthesized by reacting furfurylamine with organylchlorosilanes, chloroalkyltriorganylsilanes, and triorganylhydrosilanes. Furfuraldoxime readily reacts with triorganylchlorosilanes in the presence of triethylamine to give O-triorganylsilyl substituted oximes. It is shown for the first time that in the presence of H₂PtCl₆ aldoximes undergo dehydrocondensation with triorganylsilanes, accompanied by reduction processes. Reaction of hexamethyldisilazane with pyromucamide gives the trimethylsilylamide. Pyromuconitrile and magnesium 3-(methyldiethylsilyl)propyl chloride gives 1-furyl-4-(methyldiethylsilyl)butanone-1. Reaction of organylchlorosilanes with furfurylmercaptan and sodium furfurylmercaptide permits synthesis of the first representatives of the sulfur-containing organosilicon derivatives of furan.Part V, see [1].     

Study of furan compounds

Furyl nitro alkanols were obtained by the condensation of 1-(2-furyl)-3-propanols with nitromethane. Catalytic hydrogenation of the products gave the corresponding furyl amino alkanols.See [1] for communication L.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 147–151, February, 1972.     

Study of furan compounds

Research on synthesis of polycyclic spirans of the 1, 6-dioxaspiro-[4, 4]nonane group is continued. Electrolysis of methanol solutions of 2-furylcyclopentanol, 2-(5-methyl-furfuryl)cyclopentanol, and 2-furfuryl-1-indanol, gives, by intramolecular alkoxylation, spiro{perhydrocyclopenta[b]furan-2, 2-(5dihydrofuran)}, spiro{perhydrocyclopenta[b]furan-2, 2-(5-methoxy-5-methyl-2, 5-dihydrofuran)}, and spiro{2, 3, 3a, 8b-tetrahydro-4H-indeno[1, 2-b]furan-2, 2-(5-methoxy-2, 5-dihydrofuran)}, hitherto undescribed in the literature. Depending on the conditions, catalytic hydrogenation of these gives: spiro{perhydiocyclopenta[b]furan-2, 2-(5-methoxytetrahydrofuran)}, spiro{2, 3a, 8b-tetrahydro-4H-indeno[1, 2-b]furan-2, 2-(5-methoxytetrahydrofuran)}, spiro{perhydrocyclopenta[b]furan-2, 2-tetrahydrofuran}, and spiro{2, 3, 3a, 8b-tetrahydro-4H-indeno[1, 2-b]furan-2, 2-tetrahydrofuran}.For Part XXXI see [1].     

Intramolecular ene reaction of a chiral bicyclic lactam

The preparation of bicylic lactam 2 is described, employing an acetoacetate-based synthesis of 1,4-ketoacid 3. The lactam 2 was shown to undergo a thermal ene reaction at 280-300 degrees C to afford tricycle 7. Reduction of the ene product followed by removal of the chiral auxiliary fragment provided the unusual lactam system 9 in highly enantioenriched form.     

Chemistry of furan and thiophene compounds

1-(-Furyl)pentan-1-ol-3-one and 1-(-thienyl)pentan-1-o1-3-one were synthesized by the reaction of furfural and -formylthiophene with methyl ethyl ketone. The products were used to synthesize secondary-tertiary -glycols with -furyl and -thienyl groups attached to the secondary carbinol carbon. It was proved that these -glycols are capable of undergoing hydrolytic cleavage at the C₂–C₃ bond.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 295–297, March, 1972.     

Organosilicon compounds of the furan series. V. Furylorganylsilanes

Twelve new furylorganylsilanes and furfurylorganylsilanes are synthesized by reacting 2-furyllithium, 5-methyl-2-furyllithium, and 5-trimethylsilyl-2-furyllithium with organylchlorosilanes, organylchlorohydrosilanes, chloromethyltriorganylsilanes, and silicon tetrachloride.-(2-furyl)ethyltrimethylsilane and 1-furyl-2-trimethylsilylethanol-1, which were previously unknown, are synthesized by reacting trimethylsilylmethyl magnesium chloride with furfuryl chloride and furfural, respectively.For Part IV see [1].     

A study of furan compounds

The ethyl esters of N-phenyl-, N-p-tolyl-, and N-ethoxyphenyl--pyrrolecarboxylic acid have been synthesized by the reaction of ethyl 2, 5-dimethoxytetrahydrofuran-2-carboxylate with aniline, ptoluidine, and p-phenetidine in the presence of p-toluenesulfonic acid. The reaction of the same ester with benzylamine gives N-benzylpyrrole--carboxybenzylamine or 2,5-dimethoxytetrahydrofuran-2carboxybenzylamide, depending on the ratio of the reactants.For part XXXIX, see [1].     

A study of furan compounds

[N-(2-Furoyl)-, N-(5-methyl-2-furoyl)-, N-(5-chloro-2-furoyl)-, N-(5-bromo-2-furoyl)-, N-(5-iodo-2-furoyl)-, N-(5-nitro-2-furoyl)-, and N-(tetrahydro-2-furoyl) ureas were obtained by acylation of urea with the corresponding acid chlorides.For part XXXIV, see [23].