An expeditious, high-yielding construction of the food aroma compounds 6-acetyl-1,2,3,4-tetrahydropyridine and 2-acetyl-1-pyrroline.

[reaction: see text] The key compound responsible for the aroma of bread, 6-acetyl-1,2,3,4-tetrahydropyridine (1), has been constructed in an efficient three-step procedure from 2-piperidone in an overall yield of 56%. Compound 1 was liberated in the final step under basic conditions. A related synthetic route produced 2-acetyl-1-pyrroline (2), the principal component of cooked rice, in 10% overall yield.