Studies on the Chemical Constituents of Rutaceous Plants. LXIV. Structural Establishment of Oxyterihanine, a Phenolic Benzo [c] phenanthridone Alkaloid. Syntheses of Phenolic Benzo [c] phenanthridine Alkaloids, Terihanine and Isoterihanine, and Related Compounds

Abstract

The structure of oxyterihanine (2c), a new phenolic benzo [c] phenanthridone alkaloid which was isolated from Formosan Xanthoxylum nitidum (ROXB.) D. C. (Fagara nitida ROXB.), was established as 8-hydroxy-9-methoxy-5-methyl-2, 3-methylenedioxybenzo [c] phenanthridin-6 (5H) one by direct comparison with a synthetic specimen, which was derived from 2- (4-isopropoxy-3-methoxyphenyl) -6, 7-methylenedioxy-3, 4-dihydronaphthalen-1 (2H) -one (8a) through the synthetic sequence shown in Charts 3 and 4.
9-Hydroxy-8-methoxy-5-methyl-2, 3-methylenedioxybenzo [c] phenanthridin-6 (5H) -one [oxyisoterihanine (2d)] and two phenolic quaternary benzo [c] phenanthridine alkaloids, terihanine (1c) and isoterihanine (1d), were also synthesized.