2.5- Dimethylfuran, and

Furan undergoes phenylation rather than diazo coupling on reaction with ben-zenediazonium salts, and thiophene similarly yields 2- or 2,5-diaryl derivatives rather than coupled products. However, 2,5-dimethylfuran and 2-/-butylfuran give coupled products with 2,4-dinitrobenzenediazonium ion (Scheme 26). 

Recently, researchers have detected 2,5-dimethylfuran and 2-methylfuran and normal alkanes in kerogen of the 2.7 x 109 year old Belingwe, Rhodesia stromatolites, by the method of pyrolysis/ GC/MS [26]. They concluded that although furans could probably be derived from many compounds, their probable origin is in bacterial and algal sugars, and that the alkanes are either products of decarboxylation of fatty acids or unaltered constituents of ancient organisms. 

Scheme 6.53 Products formed by cycloadditions of 3<52-l H-naphthalene (221), liberated from 220 by KOtBu, with furan, 2,5-dimethylfuran and spiro[2.4]hepta-4,6-diene.

Quantitative kinetic data showed that photosensitized oxygenations of various pollutants (e.g., 2,5-dimethylfuran and the insecticide Disulfoton) in air-saturated natural water samples containing aquatic HS and in distilled water containing soil-extracted or commercial HA/FA were at least one order of magnitude faster than those in distilled water. 

There are photocalorimetric enthalpy data for two other ozonides, both coming from sensitized photochemical dioxygenation reactions in non-polar solvents . This study reports the enthalpies of the reactions of 2,5-dimethylfuran and 1,3-diphenylisobenzofuran to their corresponding endoperoxides to be exothermic by —45 20 and —92 25 kJmoU (the latter value is an average of the values given for different solvents). From... 

Thermally unstable azetidines may be obtained by irradiation of furan in the presence of oxazolinones or 3-ethoxyisoindolone by [7r2s+ .2s] cycloaddition (Scheme 90) (75JA7298). Benzophenone photosensitized [ 2S+W2S] cycloaddition of furan to dimethylmaleic anhydride yields an adduct (34%). This reaction has been extended to 2,5-dimethylfuran and other maleic anhydrides and maleimides (76CA(84)120785). 

The first report on the photochemical reactivity of furan toward carbonyl compounds appeared in 1963. Schenck et al. [20] reported that the irradiation of benzophenone in furan gave the corresponding adduct in 94% yield (Scheme 3.3). The structure assignment was confirmed by Gagnaire and Payo-Subiza [21]. On the basis of the NMR analysis of both the products of the same reaction and the reaction between 2,5-dimethylfuran and benzophenone. Two years later, furan... 

Nuclear substitution in the compounds under discusison is not of great importance since the most reactive positions in the furan ring, 2 and 5, are already substituted. In certain compounds such as 2,5-dimethylfuran and 5-methylfuroic acid, substituents have been introduced at positions 3 and 4 and there are instances of the elimination of one group and its replacement by another.36 73 83 85-86... 

Shiramizu, M. and Toste, F.D. (2011) On the diels-alder approach to solely biomass-derived polyethylene terephthalate (PET) Conversion of 2,5-dimethylfuran and acrolein into p-Xylene. Chemistry A European Journal, 17 (44), 12452-12457. 

Dimethylfuran and acrolein are products of degradation of biomass such as cellulose. They were used as starting materials in the synthesis of p-xylene, demonstrating the utilization of materials obtainable from biomass toward the synthesis of polyethylene terephthalate (Scheme 16.31) [33]. The key steps involve Lewis acid-catalyzed eyeloaddition followed by oxidation and further aromatization through acid-mediated dehydration. 

Benzyne intermediates formed on treatment of 5-arylthianthreniumyl perchlorates (78) with LDA in THF have been trapped by 2,5-dimethylfuran and by DMSO. ... 

Catalytic decomposition of diazoketones 167 with Rh2(OAc)4 in the presence of 2,5-dimethylfuran 94 gave a mixture of trifluoromethylfurans 168 and tricyclic compounds 169 derived from [2+4] cycloaddition of 2,5-dimethylfuran and intermediate cyclopropene [117],... 

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