防已科植物アルカロイド研究 (第202報)

ハスノバカズラ Stephania japonica MIERSのアルカロイド (補遺8) Hasubanonineの構造 (1) Hasubanolについて

抄録

Hasubanonine, m.p. 116°, C₂₁H₂₇O₅N=C₁₆H₁₂O(OCH₃)₄⋅NCH₃, one of the alkaloids of Stephania japonica MIERS (family Menispermaceae. Japanese name “Hasunohakazura”), forms acetylhasubanol, C₁₉H₁₈O₅, by the Hofmann degradation followed by acetolysis, and hydrolysis of the acetylhasubanol gives hasubanol, C₁₇H₁₆O₄, which is positive to the Gibbs reagent and forms methylhasubanol, C₁₈H₁₈O₄, on methylation. Methyl-hasubanol was confirmed as 3, 4, 6, 8-tetramethoxyphenanthrene (III) by synthesis. Since hasubanol is positive to the Gibbs reagent, Satomi assumed it to be 3, 4, 6-trimethoxy-8-hydroxyphenanthrene.
In the present series of work, hasubanol was derived to ethylhasubanol, which was proved to be 3, 4, 8-trimethoxy-6-ethoxyphenanthrene (VI) by its synthesis. It follows, therefore, that hasubanol is not II but is 3, 4, 8-trimethoxy-6-phenanthrenol (VII).