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2.5- Dialkoxy-2,5-dihydrofuran

The 2,5-dialkoxy-2,5-dihydrofurans can be obtained by electrolytic oxidation of furan in alcoholic ammonium bromide or by bromine oxidation of furan in the appropriate alcohol. ... [Pg.30]

The 2,5-dialkoxy-2,5-dihydrofurans are cyclic acetals of male-aldehyde and may be used to generate this substance in situ. Also, the 2,5-dialkoxy-2,5-dihydrofurans readily undergo hydrogenation to provide the cyclic acetals of succindialdehyde." ... [Pg.30]

In this way furanes form 2,5-dialkoxy-2,5-dihydrofuranes in high yields on electrolysis in R 0H/NH4Br (Eq. (120) ) ... [Pg.83]

Bromine or electrolytic oxidation of furan in alcoholic solution gives the corresponding 2,5-dialkoxy-2,5-dihydrofuran 159 (R = Alk). Lead tetraacetate in acetic acid oxidation yields 2,5-diacetoxy-2,5-dihydrofuran 159 (R = Ac). [Pg.418]

Electrolytic oxidation of furan in alcoholic solution gives the corresponding 2,5-dialkoxy-2,5-dihydrofuran. [Pg.429]

The acid fission of furans, to yield 1,4-dicarbonyl compounds, is not satisfactory from the preparative point of view. This fission reaction has recently been restudied.169, 287-292 It is preferable to use the route involving 2,5-dialkoxy-2,5-dihydrofurans, which on hydrogenation and acid hydrolysis give the desired 1,4-dicarbonyl compounds. [Pg.436]

If the bromination is conducted in an alcohol, trapping of the intermediate by C-5 addition of the alcohol, then alcoholysis of C-2-bromide, produces 2,5-dialkoxy-2,5-dihydrofurans, as mixtures of cis- and trans-isomers ° hydrogenation of these species affords 2,5-dialkoxy-tetrahydrofurans, extremely useful as... [Pg.349]

The bromine/methanol (18.1.1.4) oxidation of furans to give 2,5-dialkoxy-2,5-dihydrofurans and the cycloaddition of singlet oxygen (18.7) are discussed elsewhere in this chapter. 2,5-Dialkoxy-2,5-dihydrofurans can also be obtained by electrochemical oxidation in alcohol solvents or conveniently by oxidation with magnesium monoperoxyphthalate in methanol. Reaction of furan with lead(IV) carboxylates produces... [Pg.351]

Bromine/potassium acetate 2,5-Dialkoxy-2,5-dihydrofuran from furan ring... [Pg.70]

See other pages where 2.5- Dialkoxy-2,5-dihydrofuran is mentioned: [Pg.57]    [Pg.61]    [Pg.318]    [Pg.57]    [Pg.609]    [Pg.57]    [Pg.609]    [Pg.429]    [Pg.444]    [Pg.281]    [Pg.373]    [Pg.273]    [Pg.47]    [Pg.220]   
See also in sourсe #XX -- [ Pg.418 , Pg.429 ]



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