- 182. Novel Access to Furan-3-thiols and Derivatives, Impact Meat-Flavor Compounds
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A versatile process for the preparation of a number of 3-thio-substituted furans 1-4 is described.These products have very low odor thresholds and are thus potent flavor compounds.Fur-3-yl thiocyanates 10a,b as well as other S-containing analogues (2b, 7a, b, and 8) were prepared by a Michael-type addition of thiocyanic acid, thioacetic acid, alkanethiols, and sodium thiosulfate to alkynones 6 and 15, followed by cyclization (Schemes 3 and 4).The thiocyanates 10a, b were converted to mixed disulfides 3, symmetric disulfides 4, thioethers 2, and thiols 1, using 'hard' or 'soft' nucleophiles or reducing agents, respectively (Scheme 6).
- Huber, Ulrich A.,Bergamin, Desiree
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- An analysis of substituent effects on 1H and 13C NMR parameters of substituted furans. Linear free energy relationships and PM3 semiempirical calculations
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Forty five furans have been obtained in a synthetic project designed to evaluate monothiosubstituted furans as potential food flavourings. A full NMR (1H and 13C) study and PM3 molecular orbital semiempirical calculations have been carried out. Substituent-induced chemical shifts (SCS) for six and nine substituents at the 2- and 3-positions have been calculated and a separation of inductive and resonance effects of these substituents has been proposed. Finally, a linear correlation between the net atomic charges localized at ring carbons and their 13C NMR chemical shifts has been established.
- Alvarez-Ibarra, Carlos,Quiroga-Feijoo, Maria L.,Toledano, Emilio
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p. 679 - 689
(2007/10/03)
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- Process for the manufacture of furan derivatives
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The invention is concerned with a process for the manufacture of substituted furans which are, in particular, flavorants; thereby 4-hydroxy-2-yn-1-ones or acetals or ketals thereof are cyclized with nucleophilic S-compounds to 3-S-furans, whereby this 3-S atom can be optionally substituted, and the acetylene derivatives, the 4-hydroxy-2-yn-1-ones, can be optionally 1- and/or 4-alkyl or alkenyl substituted.
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- Certain 3-furyl sulfides
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Novel 3-sulfur derivatives of furan including alkyl furan-3-thiols and bis(alkyl-3-furyl) sulfides and di- and tetrahydro derivatives thereof having meaty and/or roasted aromas and flavors; processes for producing such 3-sulfur derivatives; novel flavoring compositions containing such derivatives; and novel food compositions containing such derivatives.
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