A concise synthesis of forbesione (1) and desoxymorellin (3) is presented. Central to the strategy is a biomimetic Claisen/DielsâAlder/Claisen reaction cascade that proceeds in a regioselective manner and produces the desired scaffold exclusively. The observed regioselectivity and product distribution of the Claisen/DielsâAlder/Claisen reaction are attributed to the electronic effects of the xanthone oxygen (O10), the C9 carbonyl group and the nature of the C1 functionality.
本文介绍了福尔酮(1)和脱氧毛蕊花素(3)的简明合成方法。该策略的核心是仿
生物的 Claisen/DielsâAlder/Claisen 级联反应,该反应以区域选择性的方式进行,并完全生成所需的支架。观察到的 Claisen/DielsâAlder/Claisen 反应的区域选择性和产物分布归因于
氧杂蒽酮(O10)、C9 羰基和 C1 官能团性质的电子效应。