In continuing studies on the elucidation of essential factors for the favorable biogenetictype angular methyl migration starting from 5α, 6α-epoxy-eudesman-8β, 12-olide (1) leading to several eremophilanolides, four related eudesmane-type 5, 6-epoxides (4, 5, 6, 7) have been prepared and treated under four different acid conditions. Based on the product analyses, it has been demonstrated that the following three factors seem to be important for the biogenetic-type 10-methyl migration of 1 giving eremophilane-type derivatives : i) the presence of 5α, 6α-epoxide function, ii) the spatial interaction between 10-methyl and 4β-methyl which would bring about distortion of the ring A, and iii) the presence of cis-γ-lactone moiety attached to C-7 and C-8.
在继续研究阐明从 5α,6α-环氧-桉叶烷-8β,12-内酯(1)开始的有利的
生物遗传型角甲基迁移的基本要素,从而产生几种勃瑞莫非兰内酯的过程中,制备了四种相关的桉叶烷型 5,6-环氧内酯(4,5,6,7),并在四种不同的酸性条件下进行了处理。根据对产物的分析表明,以下三个因素似乎对 1 的
生物发生型 10-甲基迁移产生埃利莫非兰类衍
生物非常重要:i) 5α,6α-
环氧化物功能的存在;ii) 10-甲基和 4β-甲基之间的空间相互作用会导致环 A 变形;iii) C-7 和 C-8 上顺式-γ-内酯分子的存在。