海人草有効成分ならびに関連化合物の研究 第27報

Kainic Acidの異性化ならびに異性体に関する研究 (13) Kainic Acidおよびその諸異性体の立体構造 その2

抄録

Lactonization of α-isokainic acid (α-XVIII) yields only α-allokainic acid lactone (α-allo-XV) from which the latter was assumed to be the cis-lactone and further that the acetic acid and isopropenyl groups is α-allokainic acid (α-allo-I) are in cis-configuration. It is thereby known that they are in trans-configuration in α-kainic acid (α-I). Since the relationship between acetic acid and isopropenyl groups in β-kainic acid (β-I) is the same as in (α-I), they must be in trans-configuration. Summarizing the facts described in this and the preceding paper, the steric structures indicated in Fig. 2 and Table I are proposed for kainic acid and the isomers.