Syntheses of Allied Compounds of Lupine Alkaloids. IV. Synthesis and Hydrogenation of 4-Oxo-4H-quinolizine Derivatives.

Abstract

Three-step reduction of 3, 6-dioxo-1H, 3H, 6H-pyrano [3, 4, 5-i, j] quinolizine (I) and a compound derived from it, 3, 6-dioxo-2-methyl-2, 3-dihydro-1H, 6H-pyrido [3, 4, 5-i, j] quinolizine (III), respectively afforded perhydropyrano [3, 4, 5-i, j] quinolizine (XVI) and 2-methylperhydropyrido [3, 4, 5-i, j] quinolizine (XIX). It was concluded that both compounds possess the cis-quinolizidine ring.