Process for preparing 2-acetyl-1-aza-1-cycloalkenes useful as flavor components for bread and rice.

摘要

Straightforvard and inexpensive syntheses of 2-acetyl-1-aza-1-cycloalkenes usefull as bread and rice flavor components, i.e. 2-acetyl-1,4,5,6-tetrahydropyridine and 2-acetyl-1-pyrroline, respectively, comprise the following steps : oxidation of cyclic amines to cyclic imines; subsequent cyanation of cyclic amines to 2-cyano-1-azacycloalkanes ; oxidation of 2-cyano-1-azacycloalkanes to 2-cyano-1-aza-1-cycloalkenes; synthesis of 2-acetyl-1-aza-1-cycloalkenes by a Grignard reaction. These syntheses give rise to the title compounds, free of side products, in a way easily amenable to industrial production.