ミカン科植物アルカロイド研究 (第9報)

キハダPhellodendron amurense RUPR. のアルカロイド その4 dl-Phellodendrineならびにその異性体の合成

抄録

The water-soluble quaternary base, phellodendrine, contained in Phellodendron amurense RUPR. (Japanese name ‘Kihada’) and Ph. amurense var. sachalinense FR. SCHM. (Japanese name ‘Hiroha-kihada’), had been shown to have a structure corresponding to L(-)-N-methylcoreximine (VIII). In the present series of work, 3, 10-dimethoxy-7-methyl-5, 6, 13, 13a-tetrahydro-8H-dibenzo a, g quinolizine-2, 11-diol (VIII), its O, O-diethyl derivative (IX), and its methine base (X) were prepared by the route shown in Chart 1 and the compounds synthesized were identified with the natural phellodendrine and its corresponding derivatives. This has proved beyond doubt that phellodendrine has the structural formula (VIII) as had been presumed. On the other hand, Manske had proposed the formula (VII) for the tertiary phenolic base, coreximine, isolated from Dicentra eximia, based on its decomposition reactions and from biogenetic consideration of this kind of bases in the plant. The structure of coreximine was also found to be correct by the preparation of the substance (VII) in the present series of work. In this connection, an isomer of phellodendrine, dl-3, 11-dimethoxy-7-methyl-5, 6, 13, 13a-tetrahydro-8H-dibenzo [a, g] quinolizine-2, 10-diol (VIIa), was also synthesized.