Syntheses of Allied Compounds of Lupine Alkaloids. III. Synthesis of 3, 6-Dioxo-1H, 3H, 6H-pyrano [3, 4, 5-i, j] quinolizine.

抄録

2-Cyanomethyl-3-methoxymethylpyridine and ethyl (3-methoxymethyl-2-pyridyl) acetate were prepared from ethyl 2-methylnicotinate. Condensation of these compounds with diethyl ethoxymethylenemalonate afforded 1, 3-bis (ethoxycarbonyl)-9-methoxymethyl-4-oxo-4H-quinolizine and 1-cyano-3-ethoxycarbonyl-9-methoxymethyl-4-oxo-4H-quinolizine. The ethoxycarbonyl group in these compounds was saponified and further decarboxylated on being heated with hydrochloric acid. A more drastic condition easily afforded 3, 6-dioxo-1H, 3H, 6H-pyrano [3, 4, 5-i, j] quinolizine.