L. Yu. Brezhnev

Synthesis of 2-substituted 3-formyl-5-methoxy-tetrahydrofurans from 2,5-dimethoxytetrahydrofuryl-3-carbinols

The acid-catalyzed rearrangement of 2,5-dimethoxytetrahydrofuryl-3-carbinol, obtained from 2,5-dimethoxy-3-formyltetrahydrofuran, gave the 2-substituted 3-formyl-5-methoxytetrahydrofuran.

Liquid-phase hydroformylation of 2,3- and 2,5-dihydrofurans

The synthesis of 3-formyl derivatives of the tetrahydrofuran series was carried out by hydroformylation of 2,3-dihydrofuran and 2,5-dimethoxy-2,5-dihydrofuran in the presence of HRh(CO)(PPh3)3. The influence of the temperature, pressure, catalyst concentration, and the nature of the solvent on the conversion of dihydrofuran, the composition of aldehydes obtained and the selectivity of their formation was investigated.

Catalytic hydroformamination of dihydrofurans

ConclusionsA preparative method has been developed for the synthesis of 3-(N-alkyliminomethyl)-tetrahydrofurans and 3-(N, N-dialylaminomethyl)tetrahydrofurans by the hydroformamination of 2,3- and 2,5-dihydrofurans in the presence of HRh(CO)(PPh3)3.

Synthesis of furan compounds with amino and imino groups at theβ-position of the side chain by the catalytic hydroformamination of 2-vinylfuran

The hydroformamination of 2-vinylfuran in the presence of HRh(CO)(PPh3)3 was used for the first time to give N- [2- (2- furyl)propyl]- N,N- dialkylamines and N- [2- (2-furyl)propylidene]- N- alkylimines.

Catalytic hydroformamination of 2,5-dimethoxy-2,5-dihydrofurans

N-Substituted 3- and 4-formylpyrroles have been obtained by hydroformamination of 2,5-dimethoxy-2,5-dihydrofurans in the presence of HRh(CO)(PPh3)3.

Trifluoroacetylation of furan compounds

Conclusions1.Furan, 2-alkylfurans, and 1,1-di(fur-2-yl)alkanes react with trifluoroacetic anhydride to giveα-trifluoroacetyl derivatives of furan.2.In the case of 2,5-dimethylfuran, the trifluoroacetylation proceeds at the exposition of the furan ring and the methyl group to form a substituted 2,5-dihydrofuran.

Some thermal transformation characteristics of dihydrosylvan

ConclusionsThe isomerization of dihydrosylvan in the vapor phase at 500–590° proceeds in two directions, and specifically with the formation of methyl cyclopropyl ketone and cyclopentanone.