Polycyclic compounds (I) can be prepared in accordance with the following reaction formula:
wherein R₁-R₈ each represents a hydrogen atom, a hydroxyl group, an alkoxyl group or a substituted or unsubstituted benzyloxy group or neighboring two groups of R₁-R₈ are coupled together to form an alkylenedioxy group; and A is an alkylene group which may be substituted by one or more alkoxycarbonyl groups, an alkenylene group which may be substituted by one or more alkoxycarbonyl groups, or a group represented by any one of the following formulas:
多环化合物 (I) 可根据以下反应式制备:
其中 R₁-R₈各自代表一个氢原子、一个羟基、一个烷氧基或一个取代或未取代的苄氧基,或 R₁-R₈ 的相邻两个基团连接在一起形成一个烷二氧基;A 是可被一个或多个烷氧羰基取代的亚烷基、可被一个或多个烷氧羰基取代的烯基、或由以下任何一个式子表示的基团: