(1) Oxidation of tokorogenin by means of chromic anhydride in acetic acid, periodic acid in ethanol and lead tetraacetate in aqueous acetic acid led to the conclusion that tokorogenin must have a glycerol moiety in ring A of the steroid nucleus.(2) Tokorogenic acid, an oxidation product from tokorogenin, forms an anhydride by heating with acetic anhydride and gives rise to a monomethyl ester (α-monoester) by treatment with methanol and hydrogen chloride, while alkaline hydrolysis of the dimethyl ester of the acid furnishes a different monomethyl ester (β-monoester). The same α-monoester also results from tokorogenic anhydride by the action of alkali in a methanol solution.(3) On the basis of the theoretical considerations and the afore-mentioned observations in the tokorogenic acid series compared with those in the camphoric acid and etiobilienic acid series, it is concluded that tokorogenic acid has to be defined as 1,3-seco-2-nor-spirostan-1,3-dioic acid (II) and hence tokorogenin as spirostan-1,2,3-triol (I).
(1) 使用
铬酸酐在
乙酸中、在
乙醇中使用周期酸,以及在
水合
乙酸中使用四
乙酸铅对托可根素的氧化,得出结论认为托可根素在类
固醇骨架的A环中必定含有
甘油基团。(2) 托可根酸是托可根素的氧化产物,通过与
乙酸酐加热形成酸酐,并通过与
甲醇和
氯化氢的处理生成单甲酯(α-单酯),而酸的二甲酯的碱性
水解则产生不同的单甲酯(β-单酯)。同样的α-单酯也可以通过在
甲醇溶液中用碱作用托可根酸酐得到。(3) 基于理论考虑以及与
樟脑酸和乙酰
生物烯酸系列的观察相比,得出结论认为托可根酸应被定义为1,3-seco-2-nor-spirostan-1,3-二
羧酸(II),因此托可根素应被定义为spirostan-1,2,3-三醇(I)。