Structure–Odor Correlations in Homologous Series of Mercapto Furans and Mercapto Thiophenes Synthesized by Changing the Structural Motifs of the Key Coffee Odorant Furan-2-ylmethanethiol

• DOI: 10.1021/acs.jafc.8b00857
• Publication Date: 2018-04-09T04:17:47Z
• Authors: Sebastian Schoenauer; Peter Schieberle
• Keywords: Furan; Homologous series

Furan-2-ylmethanethiol (2-furfurylthiol; 2-FFT, 1) is long-known as a key odorant in roast and ground coffee was also previously identified wide range of thermally treated foods such meat, bread, roasted sesame seeds. Its unique coffee-like odor quality elicited at very low concentrations, the fact that only few compounds showing similar structure have been described make 1 suitable candidate for structure-odor activity studies. To gain insight into structural features needed to evoke 46 heterocyclic mercaptans thio ethers were synthesized, 32 them first time, their qualities thresholds determined. A movement mercapto group 3-position kept aroma but led an increase threshold. separation thiol from furan ring by elongation carbon side chain caused loss thresholds, especially ω-(furan-2-yl)alkane-1-thiols with six or seven atoms chain. displacement thiophene had no significant influence on properties most studied, newly synthesized longer-chain 1-(furan-2-yl)- 1-(thiophene-2-yl)alkane-1-thiols interesting passion fruit-like scents. In total, 4 out showed like 1, none lower Besides attributes, retention indices, mass spectra, NMR data elaborated, which are helpful possible future identification these trace levels other materials.