Elecanacin, an unusual cyclobuta-fused naphthalene-1,4-dione derivative isolated from the bulbs of Eleutherine Americana Merr. et Heyne (Iridaceae) has been obtained, together with its epimer isoelecanacin, by a 2 + 2 cycloaddition resulting from irradiation of 5-methoxy-2-(2-vinyloxypropyl)naphthalene-1,4-dione. The synthesis of enantiopure elecanacin starting with (R)-propylene oxide has established the absolute configuration of the natural product and has revealed that the sample isolated from the bulbs possessed an enantiomeric excess of only 14%.
通过对 5-甲氧基-2-(2-
乙烯氧基丙基)
萘-1,4-二酮进行 2 + 2 环加成反应,从美洲
榄香烯 Merr. et Heyne(鸢尾科)的鳞茎中分离得到了一种不寻常的
环丁基融合
萘-1,4-二酮衍
生物--
榄香素及其同系物
异榄香素。从(R)-环氧
丙烷开始的对映体纯榄香脂的合成确定了
天然产物的绝对构型,并发现从鳞茎中分离出的样品对映体的过量率仅为 14%。