Difurfuryl disulfide

Furfural comes from pentose sugars in cereal straws and brans. Furfural is the precursor of furfuryl mercaptan and its disulfide, difurfuryl disulfide, which are both important chemicals for coffee, meat and roasted flavours. They are prepared by the reaction of furfural and hydrogen sulfide (Scheme 13.15). 

If the Hydrogen Sulfide and Furfural are allowed to react in a buffered ethanolic solution at -35°C, substantial yields of Difurfuryl Disulfide (FEMA 3146) are obtained. This is a powerful flavor material witii a roasted coffee and roasted meaty taste. It is widely used to obtain roasted notes in meat flavors (equation 8). 

We believe the mechanisms of the reaction are as shown in equation 9. The final step is an unusual one. The thiofurfural intermediate undergoes a redox reaction with Hydrogen Sulfide to produce Difurfuryl Disulfide and Sulfur (equation 9). The reaction is carried out in a Nitrogen atmosphere, which would preclude the facile oxidation of Furfuryl Mercaptan to Furfuryl Disulfide. 

The synthesis of furan-2-methanethiol was described by Reichstein and Staudinger (1928). Furfural (1.63) is converted into furfuryl disulfide (difurfuryl disulfide, 1.136) by treatment with the sulfide or hydrosulfide of an alkaline-earth metal or of ammonia. The disulfide in an alcoholic solution can be reduced, for example, by addition of zinc dust and a small quantity of acetic acid. A method has been described by Kofod (1955). 

Liillmann (1993b) was probably the difurfuryl disulfide. The low concentration increased from < 1 ppb to <10ppb by roasting 5 min at 220 or 230 °C and increased slightly until 260 C. 

Bis (ethylphenylcarbamodithioato-S,S )-(T-4)-zinc. See Zinc ethylphenyidithiocarbamate Bis(N-ethyl-N-phenyl) urea. See N,N -Diethyl-N,N -diphenylurea Bis (ethyixanthic) disulfide Bis (ethyixanthogen) disulfide. See Diethyl xanthogen disulfide Bis (4-fluorophenyl) sulfone. See 4,4 -Difluorodiphenyl sulfone 1,4-Bis (1-formamido-2,2,2-trichloroethyl) piperazine N,N -Bis (1-formamido-2,2,2-trichloroethyl) piperazine. SeeTriforine Bis (2-furfuryl) disulfide. See Difurfuryl disulfide... 

Furan, 2,2-dithiobis (methylene) bis-. See Difurfuryl disulfide Furane. See Furan... 

Furfuryl disulfide 2-Furfuryl disulfide. See Difurfuryl disulfide Furfuryl mercaptan... 

Beeswax, white Beeswax, yellow Benzoic, acid Benzyl tiglate y-Bisabolene Brominated vegetable oil 3-Butylidenephthalide Butyloxepanone 3-Butylphthalide Calcium lactate Caramel Castor (Ricinus communis) oil Citronellyl isovalerate Citronellyloxy acetaldehyde p-Cresyl isovalerate p-Cresyl octanoate Crotonic acid p-Cyclocitral p-Damascenone 9-Decenal trans-4-Decenal Diacetyl tartaric acid esters of mono- and diglycerides Diethyl malate Difurfuryl disulfide Dihydroeugenol Dihydro-a-ionone Dihydrojasmone Diisobutyl ketone Diisopropyl disulfide 3,4-Dimethylcyclopentane-1,2-dione Dimethyl dicarbonate 2,5 Dimethyl-3-furanthiol p-a-Dimethylstyrene Diphenyl oxide Ethyl acetate... 

Difurfuryl disulfide Furfuryl disulfide CigHggOgSg 4437-20-1 226.315 10 167 vs EtOH... 

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