The [3,5,5,7] tetracyclic skeleton of echinopines has been stereoselectively accessed through a gold(I)-catalyzed alkoxycyclization of cyclopropyl-tethered 1,6-enynes. The key bicyclo[4.2.1]nonane core of the enyne precursors was readily assembled by means of a Co-catalyzed [6 + 2] cycloaddition. Furthermore, the attempted alkoxycyclization of 1,5-enyne substrates revealed an uncovered cyclopropyl
通过
金(I)催化的环丙基束缚的1,6-
炔烃的烷氧基环化反应,立体选择性地访问了棘皮碱的[3,5,5,7]四环骨架。烯炔前体的关键
双环[4.2.1]壬烷核很容易借助共催化的[6 + 2]环加成反应组装。此外,对1,5-烯炔底物的烷氧基化尝试揭示了未发现的环丙基重排,该环丙基重排产生了[3,6,5,7]四环结构。