6-Acetyl-2,3,4,5-tetrahydropyridine explained

6-Acetyl-2,3,4,5-tetrahydropyridine is an aroma compound and flavor that gives baked goods such as white bread, popcorn, and tortillas their typical smell, together with its structural homolog 2-acetyl-1-pyrroline.

6-Acetyl-2,3,4,5-tetrahydropyridine and 2-acetyl-1-pyrroline are usually formed by Maillard reactions during heating of food. Both compounds have odor thresholds below 0.06 ng/L.^{[1] [2]}

Structure and properties

6-Acetyl-2,3,4,5-tetrahydropyridine is a substituted tetrahydropyridine and a cyclic imine as well as a ketone. The compound exists in a chemical equilibrium with its tautomer 6-acetyl-1,2,3,4-tetrahydropyridine that differs only by the position of the double bond in the tetrahydropyridine ring:

	\rightleftharpoons
6-Acetyl-2,3,4,5-tetrahydropyridine	(1 : 2)	6-Acetyl-1,2,3,4-tetrahydropyridine

References

1. T. J. Harrison, G. R. Dake. 2005. An expeditious, high-yielding construction of the food aroma compounds 6-acetyl-1,2,3,4-tetrahydropyridine and 2-acetyl-1-pyrroline. J. Org. Chem.. 70. 26. 10872–10874. 16356012. 10.1021/jo051940a.
2. De Kimpe. Norbert. Stevens, Christian. A convenient synthesis of 6-acetyl-1,2,3,4-tetrahydropyridine, the principle bread flavor component. Journal of Organic Chemistry. 1993. 58. 10. 2904–2906. 10.1021/jo00062a042.