Dimethylfuran, reaction + singlet

Broadbent et al.50 have also observed the reaction of dimethylfuran with singlet oxygen. The product of reaction is probably the ozonide ... 

Singlet oxygen reactions measured at [dye] = 3.0 x 10 4 using 2,5-dimethylfuran as the singlet oxygen trap solvent MeOH at 20°. 

Closer investigations of pseudoazulenes 26, 27, 39, and 4()50,214 revealed that irradiation of these systems in the presence of 302 produced singlet oxygen. It was possible to demonstrate the formation of 02 by quenching experiments with DABCO and 2,5-dimethylfuran. In a thermal reaction 02 adds to the pseudoazulenes, whereby dioxetane derivatives (126) are... 

Attempts to obtain stereoselective Paterno-Buchi reactions were performed carrying out the reaction between 3,4-dimethylfuran and R-isopropylidene dia-stereoisomer. The coupling products were obtained with an overall yield of 35% as a 1.2 1 mixture of diastereoisomers. Furthermore, the compound 37 was obtained with 54% ee (Scheme 3.39) [76, 77]. This behavior suggests the operation of a mechanism that is insensitive to the substitution pattern of chiral aldehydes. Reaction between an excited aldehyde (singlet or triplet state) and furan... 

Gollnick, K. and Griesbeck, A. 1983. [4+2]-Cycloaddition of singlet oxygen to 2,5-dimethylfuran isolation and reactions of the monomeric and dimeric endoperoxides. 

The rate constants of singlet oxygen reactions have been determined for a series of substituted furans by Koch, Clennan et al., and Gollnick and Griesbeck. ° Only a moderate solvent dependence was observed, which implies a concerted (possibly asynchronous) [4 -i- 2]-cycloaddition. More thermally persistent endoperoxides were obtained from alkyl-substituted furans, e.g., 2,5-dimethylfuran or furans with electron-withdrawing substituents. A few representative examples of furan endoperoxides together with their thermal stability are given in Table 25.3. 

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