Determination of the Chemical Structure of the Intense Roasty, Popcorn-like Odorant 5-Acetyl-2,3-dihydro-1,4-thiazine

Article abstract of DOI:10.1021/jf00056a043

The chemical structure of a novel intense popcorn-like odorant isolated from the reaction of cysteine and ribose was studied by one- and two-dimensional NMR spectroscopy and high-resolution mass spectrometry, and the structure elucidation was confirmed by synthetic experiments.Thus, the odorant was identified as 5-acetyl-2,3-dihydro-1,4-thiazine (ADT).A sensory study including 5-propionyl-(PDT) and 5-butanoyl-2,3-dihydro-1,4-thiazine (BDT) revealed that also PDT and BDT elicited roasty, popcorn-like odors.However, the odor threshold of the BDT was by a factor of 50 000 higher than those ADT and PDT (0.06 and 0.1 ng/L of air, respectively).Keywords: 5-Acetyl-2,3-dihydro-1,4-thiazine; 5-propionyl-2,3-dihydro-1,4-thiazine; 5-butanoyl-2,3-dihydro-1,4-thiazine; odor threshold; synthesis; cysteamine; 2,3-butanedione