THE REACTION OF 2-ALKYLTETRAHYDROPYRANS WITH ANILINE OVER ACTIVATED ALUMINA

Abstract

The vapor-phase reaction over activated alumina of 2-ethyltetrahydropyran with aniline gave 1-phenyl-2-ethylpiperidine, 1-phenyl-2-propylpyrrolidine, N-phenyl-4-heptenylamine, and N-phenyl-5-heptenylamine. 2-Methyltetrahydropyran with aniline gave 1-phenyl-2-methylpiperidine, 1-phenyl-2-ethylpyrrolidine, N-phenyl-4-hexenylamine, and N-phenyl-5-hexenylamine. The structures of the cyclic amines were confirmed by independent syntheses. The unsaturated secondary amines were reduced to known N-alkylanilines and degraded by ozonolysis. A mechanism has been proposed to account for the formation of these products.