catalyzed reaction of 7-epimeric 3β,7-diacetoxy-9β,11β-epoxy-5α-lanostanes 1 and 2 in acetic anhydride resulted in the formation of a series of skeletally rearranged products, mainly 19(10→9β)abeo-lanostanes. 19(10→9β),30(14→8α)Bis-abeo-lanostane derivative 5 possessing a novel type of the triterpene skeleton was formed as the major product in the reaction of 7α-epimer 2. The direction and extent of
三氟化硼醚化物在
乙酸酐中催化7-表异构体3β,7-
二乙酰氧基-9β,11β-环氧-5α-
羊毛甾烷1和2的反应导致一系列骨架重排产物的形成,主要是19(10→9β)的a
BEO- -lanostanes。19(10→9β),30(14→8α)双- A
BEO -lanostane衍
生物5具有一种新型的三萜骨架的形成为在7α差向异构体反应的主要产物2。9β,11β-
环氧化物1和2的重排方向和程度取决于7-乙酰氧基的构型。新化合物的结构是根据光谱学方法确定的,主要是1 H和13 C NMR。化合物5的结构通过单晶X射线衍射确认。